Surgical instrument having a differential articulation joint arrangement for accommodating a flexible actuator - Patents.com

Abstract

A surgical instrument including an articulation joint configured to establish upper and lower pathways through the articulation joint. When the surgical instrument is in a non-articulated position, the upper and lower pathways are parallel to one another and when the surgical instrument is articulated, the upper and lower pathways are concentric to one another. An upper flexible firing assembly slidably extends through the upper pathway and a lower flexible firing assembly slidably extends through the lower pathway. The upper and lower flexible firing assemblies communicate with a firing member and a differential drive assembly configured to impart axial drive motion to the upper and lower flexible firing assemblies.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This non-provisional application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 63 / 057,430, filed July 28, 2020, entitled "SURGICAL INSTRUMENTS WITH TORSION SPIN DRIVE ARRANGEMENTS," and U.S. Provisional Patent Application No. 63 / 057,432, filed July 28, 2020, entitled "ARTICULATION JOINT ARRANGEMENTS FOR SURGICAL INSTRUMENTS," the disclosures of which are incorporated herein by reference in their entireties. [Background technology]

[0002] The present invention relates to surgical instruments and to surgical stapling and severing instruments, and staple cartridges for use therewith, designed for stapling and severing tissue in a variety of devices. The surgical instruments may be configured for use in open surgical procedures, but have application in other types of surgery, such as laparoscopic, endoscopic, and robotic-assisted procedures, and may include an end effector that is articulatable relative to a shaft portion of the instrument to facilitate precise positioning within a patient. [Brief explanation of the drawings]

[0003] The novel features of the various aspects are set forth with particularity in the appended claims. However, the described aspects, both as to organization and method of operation, can best be understood by reference to the following description taken in conjunction with the accompanying drawings. [Figure 1] FIG. 1 is a perspective view of a surgical end effector portion of a surgical instrument according to at least one embodiment of the present disclosure. [Figure 2] FIG. 2 is a side view of the surgical end effector portion of FIG. 1 in a closed orientation. [Figure 3]FIG. 3 is an end view of the surgical end effector of FIG. 2. [Figure 4] FIG. 3 is a top view of the surgical end effector of FIG. 2. [Figure 5] FIG. 2 is an exploded view of a portion of the surgical instrument of FIG. 1. [Figure 6] FIG. 2 is an exploded view of the elongate shaft assembly of the surgical instrument of FIG. 1. [Figure 7] FIG. 7 is another exploded view of the elongate shaft assembly of FIG. [Figure 8] FIG. 1 is an exploded view of a firing system and a rotary drive system according to at least one aspect of the present disclosure. [Figure 9] FIG. 9 is a side view of a firing member and upper and lower flexible spine assemblies of a firing system engaged with the rotary drive screw of the rotary drive system of FIG. 8. [Figure 10] 10 is a cross-sectional view of the firing member and upper and lower flexible spine assemblies of FIG. 9. FIG. [Figure 11] FIG. 10 is a side view of the firing member and upper and lower flexible spine assemblies engaged with the rotary drive screw of FIG. [Figure 12] FIG. 12 is a cross-sectional end view of the surgical end effector of FIG. 4 taken along line 12-12 of FIG. 4. [Figure 13] 11 is an exploded perspective view of two adjacent upper vertebral members of the upper flexible spine assembly of FIG. 10. FIG. [Figure 14] FIG. 11 is an exploded perspective view of two adjacent lower vertebral members of the lower flexible spine assembly of FIG. 10. [Figure 15] FIG. 10 is a top view of the firing member and upper and lower flexible spine assemblies engaged with the rotary drive screw of FIG. [Figure 16] FIG. 9 is a perspective view of a CV drive shaft assembly of the rotary drive system of FIG. 8 in an articulated orientation. [Figure 17] FIG. 17 is a perspective view of the firing system of FIG. 8 in driving engagement with the CV drive shaft assembly of FIG. 16, according to at least one embodiment of the present disclosure. [Figure 18]FIG. 17 is a perspective view of a drive joint of the CV drive shaft assembly of FIG. [Figure 19] 19 is a cross-sectional view of a portion of the surgical instrument of FIG. 4 taken along line 19-19 of FIG. 4. [Figure 20] FIG. 2 is a partial perspective view of a proximal end portion of a surgical end effector and portions of a firing system and a rotational drive system of the surgical instrument of FIG. 1; [Figure 21] FIG. 2 is a perspective view of a rotational drive system of the surgical instrument of FIG. 1 in driving engagement with a firing system, according to at least one embodiment of the present disclosure. [Figure 22] FIG. 22 is an exploded perspective view of the rotary drive screw and thrust bearing assembly of the firing system of FIG. 21; [Figure 23] FIG. 23 is a side view of the rotary drive screw of FIG. 22. [Figure 24] 22 is a partial cross-sectional side view of a portion of the lower flexible spine assembly and a portion of the firing member of FIG. 21 in driving engagement with a portion of the rotary drive screw. [Figure 25] FIG. 2 is a perspective view of a firing member in a home or starting position within the surgical end effector of the surgical instrument of FIG. [Figure 26] 22 is a side view of the upper and lower flexible spine assemblies of FIG. 21 in driving engagement with the rotary drive screw after the firing member has been driven distally from a home or starting position. [Figure 27] FIG. 2 is a partial cross-sectional perspective view of a portion of a surgical end effector, a firing system, and a rotational drive system of the surgical instrument of FIG. 1 , with an outer elastomeric joint assembly of the articulation joint omitted for clarity, in accordance with at least one embodiment of the present disclosure; [Figure 28] FIG. 28 is another partial perspective view of a portion of the surgical end effector, firing system, and rotational drive system of FIG. 27, with portions of the outer elastomeric joint assembly and elongated shaft assembly of the articulation joint omitted for clarity. [Figure 29]FIG. 28 is a top view of the surgical end effector of FIG. 27 articulated in a first direction relative to a portion of the elongate shaft assembly, according to at least one embodiment of the present disclosure. [Figure 30] FIG. 30 is a side view of the surgical end effector of FIG. 29 articulated in another direction relative to a portion of the elongate shaft assembly, according to at least one embodiment of the present disclosure. [Figure 31] FIG. 30 is a perspective view of the surgical end effector of FIG. 29 articulated in multiple planes relative to a portion of the elongate shaft assembly, according to at least one embodiment of the present disclosure. [Figure 32] FIG. 10 is a side view of a portion of another surgical instrument employing another outer elastomeric coupling assembly in accordance with at least one embodiment of the present disclosure. [Figure 33] FIG. 33 is a partial cross-sectional perspective view of the surgical instrument of FIG. 32. [Figure 34] FIG. 33 is a perspective view of a portion of the outer elastomeric coupling assembly of FIG. 32. [Figure 35] 35 is a cross-sectional end view of a portion of the surgical instrument of FIG. 19 taken along line 35-35 of FIG. 19. [Figure 36] 36 is a cross-sectional end view of a portion of the surgical instrument of FIG. 19 taken along line 36-36 of FIG. 19. [Figure 37] FIG. 20 is a partial cross-sectional view of a portion of the anvil cap and upper vertebra member of the surgical instrument of FIG. 19, in accordance with at least one embodiment of the present disclosure. [Figure 38] FIG. 20 is a side view of a portion of the surgical end effector of the surgical instrument of FIG. 19 with the anvil in an open position and portions of the surgical end effector omitted for clarity in accordance with at least one embodiment of the present disclosure. [Figure 39] FIG. 39 is a partial cross-sectional side view of the surgical end effector of FIG. 38 with the anvil in an open position and the firing member in a home or starting position, according to at least one embodiment of the present disclosure. [Figure 40] FIG. 40 is another partial cross-sectional side view of the surgical end effector of FIG. 39 with the anvil in a partially closed position; [Figure 41] FIG. 40 is another partial cross-sectional side view of the surgical end effector of FIG. 39 with the anvil in a fully closed position and the firing member advanced distally through the surgical end effector; [Figure 42] FIG. 20 is a partial side view of the surgical end effector of FIG. 19 with parts omitted for clarity to show the anvil opening spring applying an opening motion to the anvil and with the firing member in a home or starting position. [Figure 43] FIG. 43 is another partial side view of the surgical end effector of FIG. 42 after the firing member has been moved proximally a short distance to apply a rapid closing motion to the anvil for grasping purposes. [Figure 44] FIG. 20 is a cross-sectional view of the surgical end effector of FIG. 19 with the jaws in a closed position and the firing member in a proximal-most position. [Figure 45] FIG. 45 is another cross-sectional view of the surgical end effector of FIG. 44 after the firing member has been advanced distally to a final position within the surgical end effector. [Figure 46] FIG. 10 is a perspective view of a portion of another surgical instrument. [Figure 47] FIG. 47 is a side view of the surgical end effector of the surgical instrument of FIG. 46 with the jaws in the open position; [Figure 48] FIG. 49 is another side view of the surgical end effector of FIG. 48 with the jaws in a closed position. [Figure 49] FIG. 47 is an exploded view of a portion of the surgical instrument of FIG. 46. [Figure 50] FIG. 47 is a perspective view of a firing member and portions of the upper and lower flexible spine assemblies of the firing system of the surgical instrument of FIG. [Figure 51] 51A-51C are cross-sectional side views of portions of the launch system shown in FIG. 50. [Figure 52] FIG. 52 is a partial exploded view of the upper and lower flexible spine assemblies shown in FIG. 51. [Figure 53] FIG. 51 is a partial cross-sectional end view of the upper portion of the firing member shown in FIG. 50. [Figure 54]FIG. 47 is a cross-sectional end view of the surgical end effector of the surgical instrument of FIG. 46 with the jaws in a closed position; [Figure 55] FIG. 47 is a view of the proximal surface of the annular rib member of the mobile exoskeleton assembly of the surgical instrument of FIG. [Figure 56] FIG. 56 is a view of the distal face of the annular rib member of FIG. 55. [Figure 57] FIG. 57 is a side view of the annular rib member of FIGS. 55 and 56. [Figure 58] FIG. 47 is a partial cross-sectional view of a portion of the surgical instrument of FIG. 46. [Figure 59] FIG. 47 is a side view of the articulation joint of the surgical instrument of FIG. 46 when the surgical end effector is in a non-articulated position; [Figure 60] FIG. 60 is another side view of the articulation joint of FIG. 59 when the surgical end effector is in an articulated position. [Figure 61] FIG. 47 is a partial perspective view of a portion of the surgical instrument of FIG. 46 with the surgical end effector omitted for clarity; [Figure 62] FIG. 47 is another partial perspective view of a portion of the surgical instrument of FIG. [Figure 63] FIG. 47 is another partial perspective view of a portion of the surgical instrument of FIG. [Figure 64] FIG. 47 is a perspective view of a portion of the CV drive shaft assembly and elongate shaft assembly of the surgical instrument of FIG. [Figure 65] FIG. 65 is another perspective view of the CV drive shaft assembly and elongated shaft assembly of FIG. 64 with an embodiment of a drive cover installed around the CV drive shaft assembly. [Figure 66] FIG. 65 is another perspective view of the CV drive shaft assembly and elongated shaft assembly of FIG. 64 with another drive cover embodiment installed around the CV drive shaft assembly. [Figure 67] FIG. 65 is another perspective view of the CV drive shaft assembly and elongated shaft assembly of FIG. 64 with another drive cover embodiment installed around the CV drive shaft assembly. [Figure 68]FIG. 68 is a side view of a portion of the firing system of the surgical instrument of FIG. 46 with the drive cover of FIG. 67 installed around the CV drive shaft assembly. [Figure 69] FIG. 70 is another side view of a portion of the firing system and drive cover of FIG. 68. [Figure 70] FIG. 10 is a cross-sectional view of a portion of another surgical instrument. [Figure 71] FIG. 71 is a cross-sectional end view of a surgical end effector of the surgical instrument of FIG. [Figure 72] FIG. 71 is a cross-sectional side view of a rotary drive nut engaged with a drive component of the surgical instrument of FIG. 70; [Figure 73] FIG. 10 is a partial side view of a surgical end effector of another surgical instrument employing a series of flexibly tethered drive components to drive a firing member through the surgical end effector. [Figure 74] FIG. 74 is a side view of a portion of a series of flexibly coupled drive components of the surgical instrument of FIG. 73 prior to engagement with a rotary drive gear in a surgical end effector. [Figure 75] FIG. 75 is another side view of a portion of the drive component of FIG. 74 after being engaged with a rotary drive gear to form a rigid series of drive components. [Figure 76] FIG. 75 is a partial cross-sectional view of the rotary drive system of the surgical instrument of FIG. 74, with a component in the series of flexible drive components in driving engagement with its rotary drive gear; [Figure 77] FIG. 10 is a side view of a portion of a rotational firing system and firing member of another surgical instrument. [Figure 78] FIG. 10 is a side view of a portion of a rotational firing system and firing member of another surgical instrument. [Figure 79] FIG. 10 is a side view of a portion of a rotational firing system and firing member of another surgical instrument. [Figure 80] FIG. 10 is a partial view of another surgical instrument employing a rotary drive firing system to drive a firing member through a surgical end effector with the anvil of the surgical end effector in an open position. [Figure 81]FIG. 81 is another partial side view of the surgical instrument and end effector of FIG. 80 with the anvil in a closed position; [Figure 82] FIG. 81 is a perspective view of a portion of a rotary drive firing system of the surgical instrument of FIG. 80; [Figure 83] FIG. 83 is a top view of a portion of the rotary drive launch system shown in FIG. 82. [Figure 84] FIG. 84 is a perspective view of a guide member and rotary drive shaft of the rotary drive launching system of FIG. 83; [Figure 85] FIG. 84 is a perspective view of a portion of another flexible firing drive assembly that may be used with the firing drive system of FIG. 83; [Figure 86] FIG. 84 is another perspective view of a portion of another embodiment of a flexible firing drive assembly that can be used with the firing drive system of FIG. 83. [Figure 87] FIG. 10 is a perspective view of a surgical end effector of another surgical instrument with the anvil in an open position and the surgical end effector in an unarticulated orientation; [Figure 88] FIG. 88 is an exploded view of the surgical end effector and surgical instrument of FIG. [Figure 89] FIG. 88 is a side elevational view of the articulation joint of the surgical instrument of FIG. [Figure 90] FIG. 90 is a top view of the articulation joint of FIG. [Figure 91] FIG. 90 is a perspective view of the articulation joint of FIG. 89 and a cable controlled closure pulley system for applying a closure motion to the anvil of the surgical end effector of FIG. 89; [Figure 92] 89; FIG. 90 is a perspective view of a portion of the surgical end effector of FIG. 89 articulated by the articulation joint of FIG. [Figure 93] FIG. 92 is another perspective view of the cable controlled closure pulley system of FIG. 91. [Figure 94] FIG. 94 is an end view of a pulley unit of the cable controlled pulley system of FIG. 93. [Figure 95] FIG. 95 is a side elevational view of the first lateral alpha wrap pulley of the pulley unit of FIG. 94. [Figure 96]90 is a side cross-sectional view of a portion of the surgical end effector of FIG. 89 with the anvil of the surgical end effector in an open position. [Figure 97] FIG. 97 is another side elevational view of the surgical end effector of FIG. 96 with the anvil in a closed position. [Figure 98] FIG. 88 is a perspective view of the articulation joint and cable controlled closure system of the surgical instrument of FIG. 87 with the central joint member and the distal joint member articulated relative to the proximal joint member of the articulation joint; [Figure 99] FIG. 88 is another perspective view of the articulation joint and cable controlled closure system of the surgical instrument of FIG. 87 with the distal joint member articulated through a second articulation plane relative to the central joint member of the articulation joint; [Figure 100] FIG. 88 is a side elevational view of a portion of a firing drive system of the surgical instrument of FIG. [Figure 101] FIG. 101 is another perspective view of the firing drive system of FIG. 100 with the upper and lower chain link features in an articulated position. [Figure 102] FIG. 101 is another side view of the firing drive system of FIG. 100 with the upper and lower chain link features in driving engagement with the rotary drive screw of the firing drive system. [Figure 103] FIG. 88 is a cross-sectional end view of the surgical end effector of FIG. 87 with the anvil in a closed position; [Figure 104] FIG. 88 is a cross-sectional side view of a portion of the surgical instrument of FIG. 87 with the firing member in the actuated position and the anvil in the closed position; [Figure 105] FIG. 88 is an exploded view of the rotational drive system of the surgical instrument of FIG. 87. [Figure 106] FIG. 106 is a perspective view of a first drive shaft segment and a second drive shaft segment of the rotary drive system of FIG. 105. [Figure 107] FIG. 88 is a perspective view of the surgical end effector of FIG. 87 with the rotational drive system in an articulated orientation. [Figure 108]FIG. 88 is an exploded view of a portion of the articulation joint and rotational drive system of the surgical instrument of FIG. [Figure 109] FIG. 109 is a cross-sectional view of the articulation joint and rotational drive system of FIG. 108 in an unarticulated orientation. [Figure 110] FIG. 109 is another cross-sectional view of the articulation joint and rotational drive system of FIG. 109, with the proximal joint member of the articulation joint articulated relative to the central joint member of the articulation joint. [Figure 111] FIG. 88 is a partial side elevation view of the surgical instrument of FIG. 87 showing one form of cable tensioning system with the surgical end effector in an unarticulated orientation. [Figure 112] FIG. 112 is another partial side view of the surgical instrument and cable tensioning system of FIG. 111 with the surgical end effector in an articulated orientation. [Figure 113] FIG. 88 is a partial side elevational view of the surgical instrument of FIG. 87 showing another form of cable tensioning system with the surgical end effector in an unarticulated orientation. [Figure 114] FIG. 114 is another partial side view of the surgical instrument and cable tensioning system of FIG. 113 with the surgical end effector in an articulated orientation. [Figure 115] FIG. 10 is a perspective view of a portion of another surgical instrument embodiment. [Figure 116] 116 is a perspective view of a portion of the surgical instrument of FIG. 115 with the surgical end effector portion in an articulated position relative to the elongate shaft portion thereof; [Figure 117] 117 is a side elevational view of the surgical end effector of FIG. 116 with the anvil in a closed position; [Figure 118] FIG. 118 is a top view of the surgical end effector of FIG. 117; [Figure 119] FIG. 116 is an exploded perspective view of a portion of the surgical instrument of FIG. 115; [Figure 120] FIG. 116 is a partial bottom cross-sectional view of the articulation joint and anvil of the surgical instrument of FIG. 115; [Figure 121] FIG. 121 is an exploded view of the articulation joint of FIG. 120. [Figure 122] FIG. 122 is a side view of the annular disc member of the articulation joint of FIG. 121; [Figure 123] FIG. 123 is a perspective view of the annular disc member of FIG. 122; [Figure 124] FIG. 123 is a distal face view of the annular disc member of FIG. 122; [Figure 125] FIG. 123 is a proximal face view of the annular disc member of FIG. 122; [Figure 126] FIG. 116 is a top view of a pulley unit of the surgical instrument of FIG. 115; [Figure 127] FIG. 116 is a perspective view of a portion of the articulation joint and elongate shaft assembly of the surgical instrument of FIG. 115, with the outer shaft tube omitted for clarity. [Figure 128] FIG. 127 is a side elevational view of the pulley unit of FIG. 126. [Figure 129] FIG. 127 is another side elevational view of the pulley unit of FIG. 126. [Figure 130] FIG. 127 is a perspective view of the pulley unit of FIG. 126 and the continuum shaft of the articulation joint of the surgical instrument of FIG. 115; [Figure 131] FIG. 127 is another perspective view of the pulley unit of FIG. 126 and the series of elastomeric annular spacer members of the articulation joint of the surgical instrument of FIG. 115; [Figure 132] FIG. 116 is another perspective view of the pulley unit, portions of the firing system, and articulation joint of the surgical instrument of FIG. 115; [Figure 133] FIG. 116 is a perspective view of a portion of the firing system of the surgical instrument of FIG. 115; [Figure 134] FIG. 134 is a partial cross-sectional view of the launch system of FIG. 133; [Figure 135] FIG. 116 is a perspective view of the firing system, articulation joint, and closure system of the surgical instrument of FIG. [Figure 136] 116 is a partial cross-sectional view of the surgical instrument of FIG. 115 with the surgical end effector in a non-articulated position; [Figure 137] FIG. 116 is a partial view of a different drive assembly embodiment of the firing system of the surgical instrument of FIG. 115. [Figure 138]FIG. 116 is another partial cross-sectional view of the surgical instrument of FIG. 115 with the surgical end effector in an articulated position; [Figure 139] 116 is another partial cross-sectional view of the surgical instrument of FIG. 115 with the surgical end effector in an articulated position; DETAILED DESCRIPTION OF THE INVENTION

[0004] The applicant of the present application owns the following US patent applications, filed on even date herewith, each of which is incorporated herein by reference in its entirety: -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH TORSION SPIN DRIVE ARRANGEMENTS," Attorney Docket No. END9248USNP1 / 200084-1; -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH FIRING MEMBER CLOSURE FEATURES," Attorney Docket No. END9248USNP2 / 200084-2; -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH SEGMENTED FLEXIBLE DRIVE ARRANGEMENTS," Attorney Docket No. END9248USNP3 / 200084-3; -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH FLEXIBLE BALL CHAIN DRIVE ARRANGEMENTS," Attorney Docket No. END9248USNP4 / 200084-4; -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH DOUBLE SPHERICAL ARTICULATION JOINTS WITH PIVOTABLE LINKS," Attorney Docket No. END9248USNP5 / 200084-5; -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH DOUBLE PIVOT ARTICULATION JOINT ARRANGEMENTS," Attorney Docket No. END9248USNP6 / 200084-6; -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH COMBINATION FUNCTION ARTICULATION JOINT ARRANGEMENTS," Attorney Docket No. END9248USNP7 / 200084-7; -U.S. Patent Application, entitled "METHOD OF OPERATING A SURGICAL INSTRUMENT," Attorney Docket No. END9248USNP8 / 200084-8M; -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH DUAL SPHERICAL ARTICULATION JOINT ARRANGEMENTS," Attorney Docket No. END9248USNP9 / 200084-9; -U.S. Patent Application, entitled "SURGICAL INSTRUMENTS WITH FLEXIBLE FIRING MEMBER ACTUATOR CONSTRAINT ARRANGEMENTS," Attorney Docket No. END9248USNP10 / 200084-10; and -U.S. Patent Application entitled "ARTICULATABLE SURGICAL INSTRUMENTS WITH ARTICULATION JOINTS COMPRISING FLEXIBLE EXOSKELETON ARRANGEMENTS," Attorney Docket No. END9248USNP11 / 200084-11.

[0005] As described herein and illustrated in the accompanying drawings, numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments. Well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described herein. The reader will understand that the embodiments described and illustrated herein are non-limiting examples, and thus the specific structural and functional details disclosed herein may be representative and exemplary. Variations and modifications can be made thereto without departing from the scope of the claims.

[0006] The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), "include" (and any form of include, such as "includes" and "including"), and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, a surgical system, device, or instrument that "comprises," "has," "includes," or "contains" one or more elements has those one or more elements, but is not limited to having only those one or more elements. Similarly, a system, device, or apparatus element that "comprises," "has," "includes," or "contains" one or more features has those one or more features, but is not limited to having only those one or more features.

[0007] The terms "proximal" and "distal" are used herein with reference to a clinician manipulating the handle portion of a surgical instrument. The term "proximal" refers to the portion closest to the clinician, and the term "distal" refers to the portion located away from the clinician. It will be further understood that for convenience and clarity, spatial terms such as "vertical," "horizontal," "up," and "down" may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and / or absolute.

[0008] Reference to a singular item should be understood to include the plural item, and vice versa, unless expressly stated otherwise or obvious from the context. Grammatical conjunctions are intended to represent any and all disjunctive and conjunctive combinations of joined clauses, sentences, words, etc., unless otherwise stated or obvious from the context. Thus, the term "or" should generally be understood to mean "and / or," etc.

[0009] The description of ranges of values in the present invention is intended to refer individually, rather than limiting, to any and all values falling within that range, unless otherwise specified herein, and each separate value within such range is incorporated into the specification as if it were individually recited herein. Words such as "about," "approximately," and the like, when accompanying numerical values, should be interpreted as indicating a deviation that would be understood by one of ordinary skill in the art to function satisfactorily for the intended purpose. Similarly, approximation words such as "approximately" or "substantially," when used in reference to physical properties, should be interpreted to contemplate a range of deviation that would be recognized by one of ordinary skill in the art to function satisfactorily for the corresponding use, function, purpose, etc.

[0010] Any and all examples provided herein, i.e., the use of exemplary language (such as, for example, or the like), are intended merely to better elucidate each embodiment and do not impose limitations on the scope of the embodiments. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the embodiment.

[0011] Various exemplary apparatus and methods are provided for performing laparoscopic and minimally invasive surgical procedures. However, the reader will readily appreciate that the various methods and devices disclosed herein can be used in many surgical procedures and applications, including, for example, those associated with open surgical procedures. By proceeding through the Detailed Description of the Invention section of this specification, the reader will further appreciate that the various instruments disclosed herein can be inserted into the body in any manner, such as through a natural opening, an incision or puncture made in tissue, etc. The working portions or end effector portions of these instruments can be inserted directly into the patient's body or through an access device having a working channel through which the end effector and elongate shaft of the surgical instrument can be advanced.

[0012] During various laparoscopic surgical procedures, it is common practice to insert a surgical end effector portion of a surgical instrument through a trocar placed in the patient's abdominal wall to access a surgical site located within the patient's abdomen. In its simplest form, a trocar is a pen-shaped instrument with a sharp triangular tip on one end that is typically used within a hollow tube known as a cannula or sleeve to create an opening in a body cavity through which a surgical end effector may be introduced. Such a device forms an access port within a body cavity through which a surgical end effector may be inserted. The inner diameter of the trocar's cannula necessarily limits the size of the end effector and drive support shaft of a surgical instrument that may be inserted through the trocar.

[0013] Regardless of the specific type of surgical procedure being performed, once a surgical end effector is inserted into a patient through a trocar cannula, it is often necessary to move the surgical end effector relative to a shaft assembly positioned within the trocar cannula in order to properly position the surgical end effector relative to the tissue or organ being treated. This movement or positioning of the surgical end effector relative to the portion of the shaft that remains within the trocar cannula is often referred to as "articulation" of the surgical end effector. To facilitate such articulation of the surgical end effector, various articulation joints have been developed for attaching the surgical end effector to an associated shaft. As anticipated in many surgical procedures, it is desirable to use a surgical end effector that has as large a range of articulation as possible.

[0014] Due to size constraints imposed by the size of the trocar cannula, the components of the articulation joint must be sized to be freely insertable through the trocar cannula. These size constraints also limit the size and configuration of the various drive members and components operatively associated with the motor and / or other control system supported within the housing, which may be handheld or comprise part of a larger automated system. Often, these drive members must operatively pass through the articulation joint to be operatively coupled to or operatively associated with the surgical end effector. For example, one such drive member is commonly used to impart articulation-controlled motion to the surgical end effector. During use, the articulation drive member is inactivated to position the surgical end effector in a non-articulated position to facilitate insertion of the surgical end effector through the trocar, and can then be activated to articulate the surgical end effector to a desired position once the surgical end effector has entered the patient.

[0015] Thus, the aforementioned size constraints pose many challenges in developing an articulation system that can achieve a desired range of articulation and also accommodate the variety of different drive systems required to operate the various features of a surgical end effector. Furthermore, once the surgical end effector is positioned in a desired articulation position, the articulation system and articulation joint must be able to hold the surgical end effector in that position during actuation of the end effector and performance of a surgical procedure. Such an articulation joint device must also be able to withstand the external forces to which the end effector is subjected during use.

[0016] There are a variety of surgical end effectors configured to cut and staple tissue. Such surgical end effectors generally include a first jaw feature that supports a surgical staple cartridge and a second jaw with an anvil. The jaws are supported relative to one another so that they can move between open and closed positions to position and clamp target tissue therebetween. Many of these surgical end effectors employ an axially moving firing member. In some end effector designs, the firing member is configured to engage the first and second jaws such that when the firing member is initially advanced distally, the firing member moves the jaws to the closed position. Other end effector designs employ a separate closure system that is independent of the system that operates the firing member.

[0017] The staple cartridge includes a cartridge body. The cartridge body includes a proximal end, a distal end, and a deck extending between the proximal and distal ends. During use, the staple cartridge is positioned on a first side of tissue to be stapled, and the anvil is positioned on a second side of the tissue. The anvil is moved toward the staple cartridge to press and clamp the tissue against the deck. Staples removably stored within the cartridge body can then be deployed into the tissue. The cartridge body includes staple cavities defined therein, and the staples are removably stored within the staple cavities. The staple cavities are arranged in six longitudinal rows. Three rows of staple cavities are positioned on a first side of a longitudinal slot, and three rows of staple cavities are positioned on a second side of the longitudinal slot. Other arrangements of staple cavities and staples may be possible.

[0018] The staples are supported by staple drivers within the cartridge body. The drivers are movable between a first, or unfired, position and a second, or fired, position to eject the staples from the staple cavities. The drivers are retained within the cartridge body by a retainer extending around a lower periphery of the cartridge body and include a resilient member configured to grip the cartridge body and hold the retainer against the cartridge body. The drivers are movable between their unfired and fired positions by a sled. The sled is movable between a proximal position adjacent the proximal end and a distal position adjacent the distal end. The sled includes a plurality of ramps configured to slide beneath the drivers and lift the drivers, on which the staples are supported, toward the anvil.

[0019] In addition to the above, in these surgical end effectors, the sled is moved distally by a firing member. The firing member is configured to contact the sled and push it toward the distal end. A longitudinal slot defined in the cartridge body is configured to receive the firing member. The anvil also includes a slot configured to receive the firing member. The firing member further includes a first cam engaging the first jaw and a second cam engaging the second jaw. When the firing member is advanced distally, the first cam and the second cam can control the distance between the deck of the staple cartridge and the anvil, i.e., the tissue gap. The firing member also includes a knife configured to cut tissue captured intermediate the staple cartridge and the anvil. It is desirable that the knife be positioned at least partially proximal to the beveled surface so that the staples are fired forward of the knife.

[0020] Many surgical end effectors use an axially movable firing beam that is attached to a firing member and used to impart axial firing and retraction motions to the firing member. Many such firing beams include a laminated structure that provides the firing beam with some degree of flexure around the articulation joint. As the firing beam traverses the articulation joint, it can apply a disarticulation force to the joint and cause the beam to buckle. To prevent the firing beam from buckling under pressure, the articulation joint typically includes lateral supports or "blowout" plate features to support the portion of the beam that traverses the articulation joint. For example, to advance the firing beam through an angle greater than 60 degrees, a significant amount of axial force is required. This axial force must be applied to the firing member in a balanced manner to avoid binding of the firing member with the jaws as the firing member moves distally. Any binding of the firing member with the jaws can not only result in component damage and wear, but can also require an increased amount of axial drive force to drive the firing member through the clamped tissue.

[0021] Other end effector designs employ a rotary-powered firing member. In many such designs, a rotary drive shaft extends through the articulation joint and communicates with a rotatable firing member drive shaft that is rotatably supported in one of the jaws. The firing member threadably engages the rotatable firing member drive shaft, and as the rotatable firing member drive shaft is rotated, the firing member is driven through the end effector. In such devices, the support jaw must be larger to accommodate the firing member drive shaft. In such devices, the lower end of the firing member is generally operatively associated with the drive shaft, which can also result in the application of forces that tend to unbalance the firing member when driven distally.

[0022] 1-4 illustrate one form of a surgical instrument 10 that can address many of the challenges faced by surgical instruments having articulatable end effectors configured to cut and fasten tissue. In various embodiments, the surgical instrument 10 may comprise a handheld device. In other embodiments, the surgical instrument 10 may comprise an automated system, sometimes referred to as a robotic control system, for example. In various forms, the surgical instrument 10 comprises a surgical end effector 1000 operably coupled to an elongate shaft assembly 2000. The elongate shaft assembly 2000 may be operably attached to a housing 2002. In one embodiment, the housing 2002 may comprise a handle configured to be grasped, manipulated, and actuated by a clinician. In other embodiments, the housing 2002 may comprise a portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one control motion that can be used to actuate the surgical end effectors disclosed herein and their respective equivalents. Additionally, various components may be "housed" or contained within the housing, or various components may be "associated" with the housing. In such instances, the components may not be contained with or directly supported by the housing. For example, the surgical instruments disclosed herein may be used with the various robotic systems, instruments, components, and methods disclosed in U.S. Patent No. 9,072,535, entitled "SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS," which is incorporated herein by reference in its entirety.

[0023] In one form, the surgical end effector 1000 includes a first jaw 1100 and a second jaw 1200. In the illustrated device, the first jaw 1100 includes an elongated channel 1110 having a proximal end 1112 and a distal end 1114 and configured to operably support a surgical staple cartridge 1300 therein. The surgical staple cartridge 1300 includes a cartridge body 1302 having an elongated slot 1304 therein. A plurality of surgical staples or fasteners (not shown) are stored therein on drivers (not shown) arranged in a row on each side of the elongated slot 1304. Each driver is associated with a corresponding staple cavity 1308 opening through a cartridge deck surface 1306. The surgical staple cartridge 1300 may be replaced after the staples / fasteners have been ejected therefrom. Other embodiments are contemplated in which the elongate channel 1110 and / or the entire surgical end effector 1000 may be disposed of after the surgical staple cartridge 1300 has been used. Such an end effector device may be referred to, for example, as a "disposable loading unit."

[0024] In the illustrated device, the second jaw 1200 includes an anvil 1210 including an elongated anvil body 1212 with a proximal end 1214 and a distal end 1216. In one device, a pair of reinforcing rods or members 1213 may be supported within the anvil body 1212 to provide additional stiffness and rigidity to the anvil body 1212. The anvil body 1212 includes a staple-forming lower surface 1218 facing the first jaw 1100 and may include a series of staple-forming pockets (not shown) corresponding to each of the staples or fasteners in the surgical staple cartridge 1300. The anvil body 1212 may further include a pair of downwardly extending tissue stop features 1220 formed adjacent the proximal end 1214 of the anvil body 1212. One tissue stop feature 1220 extends from each side of the anvil body 1212 such that the distal end 1222 of each tissue stop corresponds to the proximal-most staple / fastener in the surgical staple cartridge 1300. When the anvil 1210 is moved to a closed position on tissue positioned between the staple forming lower surface 1218 of the anvil 1210 and the cartridge deck surface 1306 of the surgical staple cartridge 1300, the tissue contacts the distal end 1222 of the tissue stop feature 1220, preventing the tissue from moving proximally beyond the proximal-most staple / fastener, thereby ensuring that the severed tissue is also stapled. When the surgical staple cartridge is "fired," as discussed in further detail below, the staples / fasteners supported within each staple cavity are driven through the clamped tissue, out of the staple cavity 1308, and into forming contact with the staple-forming lower surface 1218 of the anvil 1210.

[0025] 5 and 6, the proximal end 1214 of the anvil body 1212 comprises an anvil mounting portion 1230 including a pair of laterally extending mounting pins 1232 configured to be received in a corresponding mounting or pivot cradle 1120 formed in the proximal end 1112 of the elongated channel 1110. The mounting pins 1232 are pivotally retained within the mounting cradle 1120 by an anvil cap 1260, which may be attached to the proximal end 1112 of the elongated channel 1110 by mechanical snap features 1261 configured to engage retaining structures 1113 on the elongated channel 1110. See FIG. 5. In other arrangements, the anvil cap 1260 may be attached to the elongated channel 1110 by welding, adhesives, or the like. Such an arrangement facilitates pivotal advancement of the anvil 1210 relative to the surgical staple cartridge 1300 mounted within the elongate channel 1110 about a pivot axis PA between an open position ( FIG. 1 ) and a closed position ( FIGS. 2-5 ). Such pivot axis PA may be referred to herein as “fixed” in that the pivot axis PA does not translate or otherwise move when the anvil 1200 is pivoted from the open position to the closed position.

[0026] In the illustrated arrangement, the elongate shaft assembly 2000 defines a shaft axis SA and comprises a proximal shaft portion 2100 that may be operatively associated with a housing of a control portion of the surgical instrument 10 (e.g., a handheld unit, a robotic tool driver, etc.). The elongate shaft assembly 2000 further comprises an articulation joint 2200 attached to the proximal shaft portion 2100 and the surgical end effector 1000. In various examples, the proximal shaft portion 2100 comprises a hollow outer tube 2110 that may be operatively coupled to the housing 2002. See FIG. 2. As can be seen in FIG. 6, the proximal shaft portion 2100 may further comprise a rigid proximal support shaft 2120 that is supported within the hollow outer tube 2110 and extends from the housing to the articulation joint 2200. The proximal support shaft 2120 may comprise a first half 2120A and a second half 2120B that may be coupled together by, for example, welding, adhesive, etc. The proximal support member 2120 comprises a proximal end 2122 and a distal end 2124 and includes an axial passage 2126 extending therethrough from the proximal end 2122 to the distal end 2124.

[0027] As described above, many surgical end effectors use a firing member that is pushed distally through a surgical staple cartridge by an axially movable firing beam. The firing beam is typically attached to the firing member at a central region of the firing member body. This attachment location can create imbalance in the firing member as it is advanced through the end effector. Such imbalance can lead to undesirable friction between the firing member and the end effector jaws. Creating this additional friction can require the application of higher firing forces to overcome such friction and can cause undesirable wear on portions of the jaws and / or firing member. Applying higher firing forces to the firing beam can result in undesirable bending in the firing beam as it traverses the articulation joint. Such additional bending can cause the articulation joint to de-articulate, especially when the surgical end effector is articulated at relatively high articulation angles. The surgical instrument 10 uses a firing system 2300 that can address many, if not all, of these issues.

[0028] As can be seen in FIGS. 5-11 , in at least one embodiment, the firing system 2300 comprises a firing member 2310 including a vertically extending firing member body 2312 comprising an upper firing member feature 2320 and a lower firing member feature 2350. A tissue-cutting blade 2314 is attached to or formed within the vertically extending firing member body 2312. See FIGS. 9 and 11 . In at least one device, it is desirable for the firing member 2310 to pass through the anvil body 1212 with low friction, high strength, and high stiffness. In the illustrated device, the upper firing member feature 2320 comprises an upper tubular body 2322 having an upper axial passageway 2324 extending therethrough. See FIG. 10 . The lower firing member feature 2350 comprises a lower tubular body 2352 having a lower axial passageway 2354 extending therethrough. In at least one device, the upper firing member feature 2320 and the lower firing member feature 2350 are integrally formed with the vertically extending firing member body 2312. As can be seen in FIG. 12, the anvil body 1212 includes an axially extending anvil slot 1240 having a cross-sectional shape resembling a "keyhole." Similarly, the elongated channel 1110 includes an axially extending channel slot 1140 also having a keyhole cross-sectional shape.

[0029] Conventional firing member devices employ long, flexible cantilever wings extending from the upper and lower portions of the firing member. These cantilever wings slidably pass through slots in the anvil and channel, which are typically cut with rectangular T-cutters, which tend to create higher-friction surfaces. Such long cantilever wings minimize the surface area in contact with the anvil and channel, potentially resulting in wear and tear on these components. The keyhole-shaped channel slot 1140 and the keyhole-shaped anvil slot 1240 may be cut with a round T-cutter and finished with a reamer / borer, which creates a lower-friction surface. Additionally, the upper tubular body 2322 and the lower tubular body 2352 tend to be stiffer than conventional cantilever wing devices and increase the surface area in contact with the anvil and channel, which may reduce wear and result in a stronger sliding connection, respectively. In other words, because the anvil slot 1240 and channel slot 1140 are keyhole shaped and less material is removed than with conventional rectangular slots, the geometry and increased material can result in a stiffer anvil and channel compared to conventional devices.

[0030] 9-11 , in one arrangement, the firing system 2300 further comprises an upper flexible spine assembly 2400 operably coupled to the upper firing member feature 2320 and a lower flexible spine assembly 2500 operably coupled to the lower firing member feature 2350. In at least one embodiment, the upper flexible spine assembly 2400 comprises an upper series 2410 of upper vertebra members 2420 loosely coupled together by an upper flexible coupler member 2402 attached to the upper firing member feature 2320. The upper flexible coupler member 2402 may comprise an upper cable 2404 extending through an upper axial passage 2324 in the upper firing member feature 2320, the distal end 2406 of the upper cable 2404 being attached to a retainer ferrule 2408 secured to the upper axial passage 2324.

[0031] 13, each upper vertebra member 2420 comprises an upper vertebra body portion 2422 having a proximal end 2424 and a distal end 2428. An upper hollow passage 2429 extends through the upper vertebra body portion 2422 to accommodate the passage of the upper flexible coupler member 2402. Each upper vertebra member 2420 further comprises a downwardly extending upper drive feature or upper vertebra member tooth 2450 protruding from the upper vertebra body portion 2422. Each upper vertebra member tooth 2450 has a helical-shaped proximal upper surface portion 2452 and a helical-shaped distal upper surface portion 2454. Each proximal end 2424 of the upper vertebra body portion 2422 has an upper proximal mating feature 2426 therein, and each distal end 2428 has an upper distal mating feature 2430 formed therein. In at least one embodiment, the upper proximal mating feature 2426 comprises a concave recessed portion 2427, and each upper distal mating feature 2430 comprises a convex mound 2431. When positioned in the upper series 2410, the convex mound 2431 on one upper vertebra member 2420 contacts and mates with the concave recess 2427 on an adjacent upper vertebra member 2420 in the upper series 2410 to maintain the upper vertebra members 2420 in a generally aligned state, so that the spiral-shaped proximal upper surface portion 2452 and the spiral-shaped distal upper surface portion 2454 on each corresponding upper tooth 2450 can be drivingly engaged by the rotary drive screw 2700, as described in further detail below.

[0032] Similarly, in at least one embodiment, the lower flexible spine assembly 2500 comprises a lower series 2510 of lower vertebra members 2520 loosely coupled together by a lower flexible coupler member 2502 attached to the lower firing member feature 2350. The lower flexible coupler member 2502 may comprise a lower cable 2504 extending through a lower axial passage 2354 in the lower firing member feature 2350, the distal end 2506 of the lower cable 2504 being attached to a retainer ferrule 2508 secured to the lower axial passage 2354.

[0033] 14, each lower vertebra member 2520 comprises a lower vertebra body portion 2522 having a proximal end 2524 and a distal end 2528. A lower hollow passage 2529 extends through the lower vertebra body portion 2522 to accommodate the passage of the lower flexible coupler member 2502. Each lower vertebra member 2520 further comprises an upwardly extending lower drive feature or lower vertebra member tooth 2550 protruding from the lower vertebra body portion 2522. Each lower vertebra member tooth 2550 has a helical-shaped proximal lower surface portion 2552 and a helical-shaped distal lower surface portion 2554. Each proximal end 2524 of the lower vertebra body portion 2522 has a lower proximal mating feature 2526 therein, and each distal end 2528 has a lower distal mating feature 2530 formed therein. In at least one embodiment, the lower proximal mating feature 2526 comprises a concave recess 2527, and each lower distal mating feature 2530 comprises a convex mound 2531. When positioned in the lower series 2510, the convex mound 2531 on one lower vertebra member 2520 contacts and mates with the concave recess 2527 on an adjacent lower vertebra member 2520 in the lower series 2510 to maintain the lower vertebra members 2520 in a generally aligned state, so that the spiral-shaped proximal lower surface portion 2552 and the spiral-shaped distal lower surface portion 2554 on each corresponding lower tooth 2550 can be drivingly engaged by the rotary drive screw 2700, as described in further detail below.

[0034] 5, 7, and 8, in at least one arrangement, the firing drive system 2300 further comprises a rotary drive screw 2700 configured to be in driving communication with the upper series 2410 of upper vertebral members 2420 and the lower series 2510 of lower vertebral members 2520. In the illustrated arrangement, the rotary drive screw 2700 is driven by a rotary drive system 2600 including a proximal rotary drive shaft 2610 rotatably supported in an axial passage 2126 in the proximal support shaft 2120. See FIG. 7. The proximal rotary drive shaft 2610 has a proximal end 2612 and a distal end 2614. The proximal end 2612 may be in communication with a gearbox 2004 or other device driven by a motor 2006 or other source of rotational motion contained within the housing of the surgical instrument. See FIG. 2. Such a source of rotational motion rotates the proximal rotational drive shaft about shaft axis SA within axial passage 2126 in proximal support shaft 2120 .

[0035] The proximal rotational drive shaft 2610 is operably supported within the elongate shaft assembly 2000 at a location proximal to the articulation joint 2200 and is in operative communication with a constant velocity (CV) drive shaft assembly 2620 that extends or axially through the articulation joint 2200. As seen in FIGS. 8 , 16 , and 17 , in at least one device, the CV drive shaft assembly 2620 comprises a proximal CV drive assembly 2630 and a distal CV drive shaft 2670. The proximal CV drive assembly 2630 comprises a proximal shaft segment 2632 comprising a mounting shaft 2634 configured to be non-rotatably received within a similarly shaped coupler cavity 2616 in the distal end 2614 of the proximal rotational drive shaft 2610. The proximal shaft segment 2632 is in operative communication with a series 2640 of movably coupled drive couplings 2650.

[0036] As can be seen in FIG. 18 , in at least one device, each drive coupling 2650 includes a first or distal spherical portion 2660 and a second or proximal spherical portion 2652. The distal spherical portion 2660 is larger than the proximal spherical portion 2652. The distal spherical portion 2660 includes a socket cavity 2662 configured to rotatably receive the proximal spherical portion 2652 of the adjacent drive coupling 2650 therein. Each proximal spherical portion 2652 includes a pair of diametrically opposed coupling pins 2654 configured to be movably received in corresponding pin slots 2664 in the distal spherical portion 2660 of the adjacent drive coupling 2650, as can be seen in FIG. 16 . The proximal spherical portion 2652P of the proximal-most drive coupling 2650P is rotatably received in the distal socket portion 2636 of the proximal shaft segment 2632, as shown in FIG. 16 . The coupling pin 2654P is received in a corresponding pin slot 2637 in the distal socket portion 2636. As can be further seen in FIG. 16 , the distal-most drive coupling 2650D in the series 2640 of movably coupled drive couplings 2650 is movably coupled to a distal CV drive shaft 2670.

[0037] In at least one device, the distal CV drive shaft 2670 includes a proximal spherical portion 2672 dimensioned to be movably received within a socket cavity 2662D in the distal-most drive coupling 2650D. The proximal spherical portion 2672 includes a coupling pin 2674 that is movably received within a pin slot 2664D in the distal-most drive coupling 2650D. The distal CV drive shaft 2670 further includes a distally extending shaft stem 2676 configured to be non-rotatably coupled to a rotary drive screw 2700 positioned distally of the articulation joint 2200. The distal CV drive shaft 2670 includes a flange 2677 and a mounting barrel portion 2678 for receiving a thrust bearing housing 2680 thereon.

[0038] In the illustrated arrangement, when the series 2640 of movably coupled drive couplings 2650 articulates, the coupling pin 2674 remains in the corresponding pin slot 2664 of the adjacent drive coupling 2650. In the example shown in FIG. 18, each drive coupling may be capable of approximately 18 degrees of articulation in the pitch and yaw directions. FIG. 16 shows the angle of the series 2640 of drive couplings 2650 when each drive coupling 2650 in the series is articulated a full 90 degrees in pitch and yaw, resulting in an angle α of approximately 100.9 degrees. In such an arrangement, the outer surface of each distal spherical portion 2660 has clearance with the outer surface of the adjacent or nearby proximal spherical portion 2652, allowing unlimited movement up to the 18-degree limit. The rigid design and limited small angle allow the series 2640 of movably coupled drive couplings 2650 to carry high loads in the torsional direction at large overall angles.

[0039] In the illustrated arrangement, the articulation joint 2200 includes an articulation joint spring 2230 supported within an outer elastomeric joint assembly 2210. The outer elastomeric joint assembly 2210 includes a distal end 2212 attached to the proximal end 1112 of the elongated channel 1110. For example, as can be seen in FIG. 6 , the distal end 2212 of the outer elastomeric joint assembly 2210 is attached to the proximal end 1112 of the elongated channel 1110 by a pair of cap screws 2722 extending through a distal mounting bushing 2720 so as to be threadably received in the proximal end 1112 of the elongated channel 1110. The proximal end 2214 of the elastomeric joint assembly 2210 is attached to the distal end 2124 of the proximal support shaft 2120. The proximal end 2214 of the elastomeric joint assembly 2210 is attached to the distal end 2124 of the proximal support member 2120 by a pair of cap screws 2732 extending through a proximal mounting bushing 2750 so as to be threadably received in a threaded insert 2125 mounted in the distal end 2124 of the proximal support shaft 2120.

[0040] To prevent the drive joint 2650 from buckling during articulation, the series 2640 of movably coupled drive joints 2650 extends through at least one low-friction articulation joint spring 2730 supported within the outer elastomeric joint assembly 2210. See FIG. 19 . The articulation joint spring 2730 is sized relative to the drive joint 2650 such that a slight radial clearance is provided between the articulation joint spring 2730 and the drive joint 2650. The articulation joint spring 2730 is designed to carry articulation loads that may be significantly lower than the torsional firing loads. The joint spring is longer than the series 2640 of drive joints 2650, which allows the drive joint to float axially. If the "hard stack" of the series 2640 of drive joints 2650 is longer than the hard stack of the articulation joint spring 2730, the drive joint 2650 may act as an articulation compression limiter, forcing firing and articulation loads to resolve axially through the series 2640 of drive joints 2650. When firing loads resolve axially through the series 2640 of drive joints 2650, the loads may tend to straighten the articulation joint 2200, or in other words, cause articulation disengagement. If the hard stack of the articulation joint spring 2730 is longer than the hard stack of the series 2640 of drive joints 2650, the firing loads will be contained within the end effector and will not resolve through the drive joint 2650 or through the spring 2730.

[0041] To further ensure that the drive joints 2650 are always engaged with one another, a proximal drive spring 2740 is used to apply an axial biasing force to the series 2640 of drive joints 2650. For example, as can be seen in FIGS. 8 , 19, and 20 , the proximal drive spring 2740 is disposed between the proximal mounting bushing 2734 and a support flange formed between the distal socket portion 2636 and the proximal barrel portion 2638 of the proximal shaft segment 2632. In one arrangement, the proximal drive spring 2740 may comprise an elastomeric O-ring / bushing received on the proximal barrel portion 2638 of the proximal shaft segment 2632. The proximal drive spring 2740 gently biases the drive joints 2650 together, reducing any clearance that may occur during articulation. This ensures that the drive joint 2650 transmits loads torsionally. However, it will be appreciated that in at least one device, the proximal drive spring 2740 does not apply a sufficiently high axial load to create a firing load to translate through the articulation joint 2200.

[0042] 9 and 10 , the upper firing member feature 2320 on the firing member 2310 includes a distal upper firing member tooth segment 2330 that corresponds to one half of the upper teeth 2450 on each upper vertebra member 2420. Additionally, a proximal upper firing member tooth 2336 that is identical to the upper tooth 2450 on each upper vertebra member 2420 is spaced apart from the distal upper firing member tooth segment 2330. The distal upper firing member tooth segment 2330 and the proximal upper firing member tooth 2336 may be integrally formed with the upper firing member feature 2320 of the firing member 2310. Similarly, the lower firing member feature 2350 of the firing member 2310 includes a distal lower firing member tooth 2360 and a proximal lower firing member tooth 2366 that are integrally formed on the lower firing member feature 2350. For example, in at least one device, firing member 2310 with rigidly attached teeth 2330, 2336, 2360, and 2366 may be fabricated at once as one unitary component using conventional metal injection molding techniques.

[0043] As discussed above, each of the upper vertebra members 2520 is movably received on an upper flexible coupler member 2402 in the form of an upper cable 2404. As discussed above, the distal end 2406 of the upper cable 2404 is secured to the upper firing member feature 2320 of the firing member 2310. Similarly, each of the lower vertebra members 2520 is movably received on a lower flexible coupler member 2502 in the form of a lower cable 2504. The distal end 2506 of the lower cable 2504 is secured to the lower firing member feature 2350 of the firing member 2310. In at least one device, the upper cable 2404 and the lower cable 2504 extend through the proximal shaft portion 2100 and may interface with a bailout device supported within the housing to retract the firing member 2310 to its home or starting position in the event of a failure of the firing member drive system, as described in further detail below.

[0044] Referring again to FIG. 8, the axial length AL of the upper series 2410 of the upper vertebral members 2420 u and the axial length AL of the lower series 2510 of the lower vertebra member 2520 land must be equal and long enough to facilitate full distal advancement of the firing member 2310 from a home or starting position to a distal-most end position within the staple cartridge while the most proximal upper vertebra member 2420 in the upper series 2410 of upper vertebra members 2420 and the most proximal lower vertebra member 2520 in the lower series 2510 of lower vertebra members 2520 remain in driving engagement with the rotary drive screw 2700. As can be seen in FIG. 8 , the upper compression limit spring 2421 is configured to interface with the most proximal upper vertebra member 2420P in the upper series 2410 of upper vertebra members 2420. The upper compression limit spring 2421 is held in biasing engagement with the proximal-most upper vertebra member 2420P by an upper spring holder 2423 journaled on the upper cable 2404 and held in place by an upper ferrule 2425 crimped onto the upper cable 2404. The upper cable 2404 extends through an upper hypotube 2433 supported in the proximal support shaft. Similarly, the lower compression limit spring 2521 is configured to interface with the proximal-most lower vertebra member 2520P in the lower series 2510 of lower vertebra members 2520. The lower compression spring 2521 is held in biasing engagement with the proximal-most lower vertebra member 2520P by a lower spring holder 2523 journaled on the lower cable 2504 and held in place by a lower ferrule 2525 crimped onto the lower cable 2504. The lower cable 2504 extends through a lower hypotube 2533 that is supported within the proximal support shaft.

[0045] As the upper vertebra member 2420 and the lower vertebra member 2520 angle through the articulation joint (after the end effector is placed in an articulated position), the gap between the respective vertebra members 2420, 2520 increases in each series 2410, 2510, causing the springs 2421, 2521 to become tighter. The compression limit springs 2421, 2521 provide sufficient slack in the cables 2404, 2504, respectively, to allow the vertebra members 2420, 2520 to angle over the most extreme articulation angles. If the cables 2404, 2504 are pulled too tight, the spring holders 2423, 2523 will contact their respective proximal-most vertebra members 2420P, 2520P. Such a compression limiter ensures that the vertebra members 2420, 2520 in each series 2410, 2510 always remain close enough together so that the rotary drive screw 2700 will always drivingly engage them in a manner discussed in more detail below. Once the vertebra members 2420, 2520 are again linearly aligned, the compression limit springs 2421, 2521 can partially relax while still maintaining some compression between the vertebra members.

[0046] As described above, when the upper vertebra members 2420 are disposed in the upper series 2410 and the lower vertebra members 2520 are disposed in the lower series 2510, the convex mounds and concave grooves of each vertebra member and the compression limiter springs function to maintain the upper and lower vertebra members in a relatively linear alignment for driving engagement by the rotary drive screw 2700. As can be seen in Figures 9 and 10, when the upper vertebra members 2420 are linearly aligned, the upper teeth 2450 are spaced apart from one another by open spaces generally designated 2460 which facilitate driving engagement with the helical drive threads 2170 on the rotary drive screw. Similarly, when the lower vertebra member 2520 is linearly aligned, the lower vertebra member teeth 2550 are spaced apart from one another by open spaces generally designated 2560 which facilitate driving engagement with the helical drive threads 2170 of the rotary drive screw 2700.

[0047] 8 and 22, the rotary drive screw 2700 includes a screw body 2702 having a socket 2704 therein for receiving the distally extending shaft stem 2676 of the distal CV drive shaft 2670. Internal radial grooves 2714 (FIG. 10) are formed in the screw body 2702 for supporting a plurality of ball bearings 2716 therein. In one arrangement, for example, twelve ball bearings 2716 are employed. The radial grooves 2714 support the ball bearings 2716 between the screw body 2702 and the distal end of the thrust bearing housing 2680. The ball bearings 2716 function to distribute the axial load of the rotary drive screw 2700 and significantly reduce friction through the rolling motion of the balls.

[0048]

[00137] As can be seen in FIG. 23, a helical drive thread 2710 is provided around the screw body 2702 and functions to form a proximal thread scoop feature 2712. The proximal thread scoop feature 2712 is formed with a first pitch 2713, and the remainder of the helical drive thread 2710 is formed with a second pitch 2715 that is different from the first pitch 2713. In FIGS. 22 and 23, region 2718 indicates where the first pitch 2713 and the second pitch 2715 converge. In at least one embodiment, the first pitch 2713 is greater than the second pitch 2715 to ensure that the rotary drive screw 2700 captures and "scoops up" or drivingly engages all of the upper vertebral members 2420 and all of the lower vertebral members 2520. 24, the proximal end 2717 of the helical drive thread 2710 having a first pitch 2713 is scooped into the open space 2560 between two adjacent lower vertebra member teeth 2550A and 2550B, while the central portion 2719 of the helical drive thread 2710 having a second pitch 2715 is drivingly engaged with the helical distal lower surface portion 2554 on the lower vertebra member tooth 2550B and the helical proximal lower surface portion 2552 on the proximal lower firing member tooth 2366. As can also be understood, the scoop feature 2712 may not contact the helical distal lower surface portion 2554A of the lower vertebra member tooth 2550A when scooping the lower vertebra member tooth 2550B when driving the firing member 2310 distally. The helical drive threads 2710 interface with the teeth 2450 of the upper vertebra member 2420 in a similar manner.

[0049] The power screw is a threaded rod with a nut that extends a full 360 degrees around it. Rotation of the power screw advances or moves the nut longitudinally. However, in the present device, due to space constraints, a full 360-degree nut cannot fit inside the end effector. In a general sense, the upper and lower flexible spine assemblies 2400 and 2500 comprise radially / longitudinal segmented "power screw nuts" that are rotatably driven by a rotary drive screw 2700. When the rotary drive screw is rotated in a first rotational direction, the rotary drive screw 2700 drives one or more vertebra members in each of the upper and lower series of vertebra members longitudinally, while the vertebra members 2420, 2520 remain radially in the same location. The upper and lower series 2410, 2510 are constrained to rotate around the rotary drive screw 2700 and can only move longitudinally. In one arrangement, the upper vertebral members 2420 of the upper series 2410 and the lower vertebral members 2520 of the lower series 2510 each surround the rotary drive screw 2700 by less than 10 degrees each.

[0050] FIG. 25 shows the firing member 2310 in a home or starting position. As can be seen in FIG. 25, a portion of the helical drive thread 2710 on the rotary drive screw 2700 is engaged between the distal upper firing member tooth segment 2330 and the proximal upper firing member tooth 2336, and another portion of the helical drive thread 2710 is engaged between the distal lower firing member tooth 2360 and the proximal lower firing member tooth 2366 on the firing member 2310. Such an arrangement allows the rotary drive screw 2700 to precisely control the distal and proximal movement of the firing member 2310, which can result in precise movement of the anvil 1210, as discussed in further detail below. When the firing member 2310 is advanced sufficiently distally during the firing stroke, the helical drive thread 2710 operably engages the teeth on the upper and lower vertebrae. See FIG. 26.

[0051] The surgical instrument 10 also includes an articulation system 2240 configured to impart articulation to the surgical end effector 1000 to articulate the surgical end effector relative to the elongate shaft assembly 2000. In at least one arrangement, for example, the articulation system includes four articulation cables 2242, 2246, 2250, and 2254 extending through the elongate shaft assembly 2000. See FIG. 27. In the illustrated arrangement, the articulation cables 2242, 2246 pass through a proximal mounting bushing 2750, the proximal end 2214 of the elastomeric joint assembly 2210, and a central rib segment 2216 that is secured to the distal end 2212 of the elastomeric joint assembly 2210 or another portion of the surgical instrument. Similarly, articulation cables 2250 and 2254 pass through proximal mounting bushing 2750, proximal end 2214 of elastomeric joint assembly 2210, and central rib segment 2218 that is secured to distal end 2212 of elastomeric joint assembly 2210 or other portion of the surgical end effector. Cables 2242, 2246, 2250, and 2254 are operatively associated with an articulation control system supported within the housing of surgical instrument 10. For example, a proximal portion of each cable 2242, 2246, 2250, and 2254 may be wound onto a corresponding rotating spool or cable management system 2007 ( FIG. 2 ) within the housing portion of surgical instrument 10 that is configured to pay out and retract each cable 2242, 2246, 2250, and 2254 in a desired manner. The spool / cable management system may be motor-driven or manual (e.g., ratcheting device). Figure 29 illustrates articulation of the surgical end effector 1000 relative to the elongate shaft assembly 2000 through a first plane of articulation. Figure 30 illustrates articulation of the surgical end effector 1000 relative to the elongate shaft assembly 2000 through a second plane of articulation. Figure 31 illustrates articulation of the surgical end effector 1000 relative to the elongate shaft assembly 2000 through multiple planes of articulation.

[0052] 32-34 illustrate an alternative articulation joint 2200' in the form of an elastomeric joint assembly 2210'. As can be seen in FIG. 33, each articulation cable passes through a corresponding spring 2215' attached to a rib 2216' of the elastomeric joint assembly 2210'. For example, cable 2242 extends through spring 2244. Cable 2246 extends through spring 2248. Cable 2250 extends through spring 2252, and cable 2254 extends through spring 2256. As described above, the end effector is articulated by pulling or releasing the appropriate cables 2242, 2246, 2250, and 2254. To achieve a greater angle of articulation with greater joint stability, each of the springs 2244, 2248, 2252, and 2256 can slide through the ribs of the elastomeric joint to push against the end effector and pull on the cables extending therethrough. The springs 2244, 2248, 2252, and 2256 also retract into the ribs when the cables 2242, 2246, 2250, and 2254 are pulled tight. Each of the springs 2244, 2248, 2252, and 2256 loosely seats on the particular cable that passes through it. Each cable and corresponding spring can be supported within the elongate shaft assembly 2000 and terminate in or otherwise coupled to a corresponding solid rod that can be pushed or pulled from its proximal end. When a cable is pulled, the corresponding spring carries little or no load. When the spring is compressed, the cable carries little load but serves to limit the movement of the end effector. This linkage between the cable and the spring can facilitate higher angles of articulation, which can approach 90 degrees, for example.

[0053] Because the radially / longitudinal segmented power screw nut arrangement disclosed herein does not have the same constraints as a 360-degree nut, the upper vertebra members 2420 of the upper series 2410 and the lower vertebra members 2520 of the lower series 2510 are constrained to ensure that their loads are transferred to the firing member in the longitudinal direction. To maintain each of the upper vertebra members 2420 in a desired orientation and to prevent the upper vertebra members 2420 from binding or losing orientation as they move through the articulation joint 2200, the upper vertebra members 2420 are aligned to pass through an upper sleeve 2470 that extends through the upper portion of the outer elastomeric joint assembly 2210 of the articulation joint 2200. See FIGS. 27, 28, and 35. The distal end 2472 of the upper sleeve 2470 is supported within the proximal end 1112 of the elongate channel 1110, and the proximal end 2474 of the upper sleeve 2470 is supported within the distal end of the proximal support shaft 2120. The upper sleeve 2470 is fabricated from a polymer or plastic material that has a low coefficient of friction and is flexible to allow the upper sleeve 2470 to flex with the outer elastomeric coupling assembly 2210. The upper sleeve 2470 prevents the upper vertebra member 2420 from contacting the outer elastomeric coupling assembly 2210, which is fabricated from an elastomeric material that may have a higher coefficient of friction than the coefficient of friction of the material of the upper sleeve 2470. In other words, the upper sleeve 2470 forms a low-friction, flexible, continuous, uninterrupted, and completely enclosed path for the upper vertebra member 2420 as it traverses the articulation joint 2200.

[0054] Similarly, a lower sleeve 2570 is employed to support the lower vertebra member 2520 as it passes through the articulation joint 2200. The distal end 2572 of the lower sleeve 2570 is supported within the proximal end of the elongated channel, and the proximal end of the lower sleeve 2570 is supported within the distal end of the proximal support shaft 2120. Similar to the upper sleeve 2470, the lower sleeve 2570 is fabricated from a polymer or plastic material that has a low coefficient of friction and is flexible to allow the lower sleeve 2570 to flex along with the outer elastomeric joint assembly 2210. The lower sleeve 2570 prevents contact between the lower vertebra member 2520 and the outer elastomeric joint assembly 2210 as it passes through the articulation joint 2200. Stated another way, the lower sleeve 2570 forms a low-friction, flexible, continuous, uninterrupted, and fully enclosed path for the lower vertebral member 2520 as it traverses the articulation joint 2200. In various embodiments, the upper sleeve 2470 and the lower sleeve 2570 are configured to bend freely without kinking. To prevent kinks from forming in the sleeves, in at least one device, the sleeves 2470, 2570 are supported within the outer elastomeric joint assembly 2210 so that the sleeves can move axially. For example, when the articulation joint angles upward, the lower sleeve 2570 can slide distally and have a larger bend radius. The upper sleeve 2470 in the same example can slide proximally and have a tighter bend radius. The axial movement reduces the amount of material exposed to the outside of the fitting assembly 2210 that may otherwise be susceptible to kinking under tight bend radii. In at least one arrangement, the distal end 2472 of the upper sleeve 2470 is formed with an upper scoop 2476 configured to feed the upper vertebra member 2420 into the anvil cap 1260. Similarly, the distal end of the lower sleeve 2570 can be formed with a lower scoop configured to feed the lower vertebra member 2520 into the channel slot 1140 in the elongated channel 1110.

[0055] As described above, the anvil mounting portion 1230 may include a pair of laterally extending mounting pins 1232 configured to be received in corresponding mounting or pivot cradles 1120 formed in the proximal end 1112 of the elongated channel 1110. The mounting pins 1232 are pivotally retained within the mounting cradle 1120 by an anvil cap 1260 attached to the proximal end 1112 of the elongated channel 1110 in the manner described above. The anvil cap 1260 includes a proximal end 1262 and a distal end 1264 and has a keyhole-shaped vertebra passage 1266 extending therethrough to accommodate passage therethrough of the upper firing member feature 2320 and the upper vertebra member 2420. FIG. 36 illustrates the vertebra passage 1266 within the anvil cap 1260. As the rotary drive screw 2700 applies a load to the upper vertebra member 2420, the vertebra member 2420 tends to tilt around region A in FIG. 37, so the upper vertebra member teeth 2450 are no longer perpendicular to the rotary drive screw 2700 and may instead experience higher pressure line contact. Region B in FIG. 37 indicates where the upper vertebra member 2420 stops tilting. To ensure that the majority of the load remains longitudinal and performs useful work, the upper vertebra member teeth 2450 must be angled the same amount as the upper vertebra member 2420 tilts. Thus, as the upper vertebra member 2420 tilts, the upper vertebra member teeth 2450 still maintain surface contact with the helical drive member 2710 on the rotary drive screw 2700 and all of the load is directed longitudinally and not vertically. The slightly angled teeth 2450 of the upper vertebra member allow the vertebra member 2420 to behave like a square thread when tilted, better distributing the load and reducing pressure contact. By directing the majority of the load longitudinally, normal loads are avoided, which can result in the establishment of friction that opposes the longitudinal load. The upper vertebra member 2420 reacts similarly as it passes through the keyhole-shaped anvil slot 1240. Similarly, the lower vertebra member 2520 reacts similarly as it passes through the keyhole-shaped, axially extending channel slot 1140 in the elongated channel 1110.

[0056] In the illustrated device, the anvil 1210 is moved to the open position by a pair of anvil springs 1270 supported within the proximal end of the elongated channel. See Figures 38, 42, and 43. The springs 1270 are positioned to apply a pivotal biasing force to corresponding anvil control arms 1234 that may be integrally formed with and extend downwardly from the anvil mounting portion 1230. See Figure 38.

[0057] 39-41 show portions of the anvil 1210, firing member 2310, and anvil cap 1260 when the anvil 1210 is open (FIG. 39), when the anvil 1210 is partially closed (FIG. 40), and after the firing member has been advanced distally from a home or starting position (FIG. 41). As seen in FIG. 39, when the firing member 2310 is in a home or starting position, the upper firing member feature 2320 is fully received within the vertebra passage 1266 in the anvil cap 1260. During the firing stroke, the upper firing member feature 2320 and the upper vertebra members 2420 in the upper series 2410 must transition from the vertebra passage 1266 in the anvil cap 1260 into the keyhole-shaped anvil slot 1240. Therefore, it is desirable to minimize any gap "G" between the anvil mounting portion 1230 and the distal end 1264 of the anvil cap 1260. To minimize this gap G while facilitating unhindered pivotal advancement of the anvil 1210, the distal end 1264 of the anvil cap 1260 is formed with a curved cap surface 1265 that matches a curved mating surface 1231 on the anvil mounting portion 1230. Both surfaces 1265, 1231 are curved and concentric about the pivot axis PA or some other reference point. Such an arrangement allows the anvil 1210 to move radially and not interfere with the anvil cap 1260 while maintaining a minimal gap G therebetween. The gap G between the anvil mounting portion 1230 and the distal end 1264 of the anvil cap 1260 is significantly shorter than the length of the upper vertebra members 2420, which facilitates easy transition of each upper vertebra member 2420 from the vertebra passage 1266 in the anvil cap 1260 into the keyhole-shaped anvil slot 1240. Additionally, to further assist the transition of the upper firing member feature 2320 into the keyhole-shaped anvil slot 1240, a ramp 1241 is formed adjacent to the curved mating surface 1231 on the anvil mounting portion 1230. When the firing member 2310 is initially advanced distally from a home or starting position, the distal end of the upper firing member feature 2320 contacts the ramp surface 1241 and begins to impart a closing motion to the anvil 1210, as seen in FIG.Further distal advancement of the firing member 2310 during the firing stroke or firing sequence will cause the upper firing member feature to enter the keyhole-shaped anvil slot 1240, fully closing the anvil 1210 and holding the anvil 1210 in the closed position during the firing sequence. See FIG. 41 .

[0058] Generally, the highest firing forces established in an endocutter are associated with cutting and stapling tissue. If these same forces can be used to close the anvil, the forces generated during pre-clamping and grasping of tissue can be similarly high. In at least one device, the firing member body 2312 further includes firing member wings or tabs 2355 extending laterally from each side of the firing member body 2312. See FIGS. 15 and 36 . The firing member wings 2355 are positioned to contact corresponding anvil control arms 1234 when the firing member 2310 is driven in the proximal direction PD from a home or starting position to rapidly close the anvil 1210 for grasping purposes. In at least one device, when the firing member 2310 is in the home or starting position, the firing member wings 2355 are located distal to the anvil control arms 1234, as shown in FIG. 42 . As the firing member 3210 is moved proximally, the firing member wing 2355 pushes against the anvil control arm 1234 (pivot direction C) against the bias of the anvil spring 1270. See FIG. 42. In one arrangement, the firing member 2310 only needs to move a short distance D to pivot the anvil 1210 to the closed position. In one embodiment, the distance D may be approximately 0.070 inches in length, for example. This short movement allows for a rapid response. Because the anvil pivot point or pivot axis PA is relatively far from the firing member wing 2355 creating a substantial moment arm, proximal movement of the firing member 2310 (and firing member wing 2355) results in a high preload torque being applied to the anvil 1210, moving the anvil 1210 to the closed position. Thus, the firing member wing 2355 may be referred to herein as a "preload feature." See FIG. 43. Thus, by advancing the firing member 2310 proximally a short distance D to quickly pivot the anvil 1210 to a closed position, the clinician can use the surgical end effector 1000 to grasp and manipulate tissue between the anvil 1210 and the surgical staple cartridge 1300 without cutting the tissue and forming staples.

[0059] The firing member 2310 can be moved in the proximal direction PD by rotating the rotary drive screw 2700 in a second rotational direction. Thus, when the firing member 2310 is in a "home" or starting position, the anvil 1210 can be biased to a fully open position by the anvil spring 1270. Actuating the rotary drive system 2600 to impart rotational motion to the rotary drive screw 2700 in a first rotational direction advances the firing member 2310 distally from the home or starting position and imparts an anvil closing motion to the anvil 1210, closing and moving the anvil to clamp the target tissue between the anvil 1210 and the surgical staple cartridge 1300. Continued rotation of the rotary drive screw in the first rotational direction continues to advance the firing member 2310 distally through the surgical end effector 1000. As the firing member 2310 moves distally, it contacts a sled 1312 ( FIG. 19 ) supported within the surgical staple cartridge 1300, driving the sled 1312 distally through the staple cartridge body 1302. When the firing member 2310 is in a home or starting position, the surgeon may desire to grasp and manipulate tissue using the surgical end effector. To do so, the rotational drive system is actuated to impart a second rotational drive motion to the rotary drive screw 2700 in a second rotational direction opposite the first rotational direction. Such rotational motion of the rotary drive screw 2700 in the second rotational direction will drive the firing member 2310 proximally from the starting position and rapidly pivot the anvil 1210 to the closed position. Thus, according to at least one embodiment, the “home or starting position” of the firing member 2310 is not its proximal-most position.

[0060] If the rotational drive system 2600 stops rotating during the firing process, the firing member 2310 may become stuck within the surgical end effector. In such an instance, the upper firing member feature 2320 may remain engaged with the anvil 1210 and the lower firing member feature 2350 may remain engaged with the elongated channel 1110, thereby preventing the surgeon from moving the anvil 1210 to the open position and releasing the tissue clamped between the anvil 1210 and the surgical staple cartridge 1300. This may occur, for example, if the motor or other control device that provides the rotational drive motion to the rotational drive shaft 2610 fails or otherwise becomes inoperable. In such an instance, the firing member 2310 may be retracted to a home or starting position within the surgical end effector 1000 by pulling the upper cable 2404 and the lower cable 2504 proximally. For example, the proximal portions of the upper cable 2404 and the lower cable 2505 may be wound on a rotating spool or cable management system 2009 ( FIG. 2 ) within the housing portion of the surgical instrument 10, which is configured to pay out the upper cable 2404 and the lower cable 2504 during the firing stroke and to retract the cables 2404, 2504 proximally when it is necessary to retract the firing member 2310. The cable management system 2009 may be motor-driven or manual (such as a ratchet device) to impart retraction motion to the cables 2404, 2504. As the cables 2404, 2504 are retracted, the upper vertebra member 2420 and the lower vertebra member 2520 rotate the rotary drive screw 2700 in an opposite direction.

[0061] The following equation determines whether the rotary drive screw 2700 rotates in the reverse direction, taking into account the lead (L), pitch diameter (d p ), tooth angle (α), and friction (μ).

[0062]

number

[0063] The rotary drive screw 2700 can self-lock if the above equation is true. In most cases, in many instances, the pitch diameter is nearly fixed for the endocutter, but the lead angle and tooth angle are variable. Because the upper and lower vertebral member teeth 2450, 2550 are nearly square, the rotary drive screw 2700 is likely back-drivable (cos(90)=1). The lead of the upper and lower vertebral member teeth 2450, 2550 can also be advantageous in that the rolling friction between the vertebral members 2420, 2520 and the rotary drive screw 2700 is more likely to allow the rotary drive screw 2700 to be back-driven. Thus, in an emergency, the surgeon can perform a quick "bail-out" by pulling the upper and lower cables 2404, 2504 proximally and fully retracting the firing member 2310.

[0064] As described above, the relative control motion for the rotational drive system 2600 and the various cable management systems used in connection with the firing system 2300 and articulation control system 2240 may be supported within a housing 2002, which may be handheld or may comprise a portion of a larger automated surgical system. The firing system 2300, articulation control system 2240, and rotational drive system 2600 may be motor controlled and operated by one or more control circuits, for example.

[0065] One method of using the surgical instrument 10 may include using the surgical instrument 10 to cut and staple target tissue within a patient using laparoscopic techniques. For example, one or more trocars may be placed through a patient's abdominal wall to provide access to target tissue within the patient. The surgical end effector 1000 may be inserted through one trocar, and one or more cameras or other surgical instruments may be inserted through the other trocars. To allow the surgical end effector 1000 to pass through a trocar cannula, the surgical end effector 1000 must be positioned in an unarticulated orientation and the jaws 1100 and 1200 closed. For example, to hold the jaws 1100 and 1200 in a closed position for insertion, the rotary drive system 2600 may be actuated to impart a second rotational motion to the rotary drive screw 2700, moving the firing member 2310 proximally from a start position and moving the anvil 1210 (jaws 1200) to a closed position. See FIG. 44. The rotary drive system 2600 is deactivated to hold the firing member 2310 in position. Once the surgical end effector is through the trocar and into the abdomen, the rotary drive system 2600 can be activated such that the rotary drive screw 2700 drives the firing member 2310 distally back to the starting position, where the anvil spring 1270 pivots the anvil 1210 to the open position. See FIG. 38.

[0066] Once inside the abdomen, the surgeon may need to articulate the surgical end effector 1000 to a favorable position before engaging the target tissue. The articulation control system 2240 is then actuated to articulate the surgical end effector in one or more planes relative to a portion of the elongate shaft assembly 2000 received within the trocar cannula. Once the surgeon orients the surgical end effector 1000 to a desired position, the articulation control system 2240 is deactuated to hold the surgical end effector 1000 in the articulated orientation. The surgeon can then use the surgical end effector to grasp the target tissue or adjacent tissue by actuating the rotary drive system to rotate the rotary drive screw in a second rotational direction to move the firing member proximally and rapidly close the anvil 1210 to grasp tissue between the anvil 1210 and the surgical staple cartridge 1300. The anvil 1210 may be released by reversing the rotation of the rotary drive screw 2700. This process may be repeated as necessary until the target tissue is properly positioned between the anvil 1210 and the surgical staple cartridge 1300.

[0067] Once the target tissue is positioned between the anvil 1210 and the surgical staple cartridge, the surgeon can initiate the closure and firing process by actuating the rotational drive system 2600 to drive the firing member 2310 distally from a start position. As the firing member 2310 moves distally from the start position, it imparts a closing motion to the anvil 1210, moving the anvil 1210 from the open position to the closed position in the manner described above. As the firing member 2310 moves distally, it holds the anvil 1210 in the closed position, thereby clamping the target tissue between the anvil 1210 and the surgical staple cartridge 1300. As the firing member 2310 moves distally, it contacts a sled 1312 supported within the surgical staple cartridge 1300 and drives the sled 1312 distally through the staple cartridge body 1302. The sled 1312 sequentially drives an array of drivers supported within the staple cartridge toward the clamped target tissue. Each driver has one or more surgical staples or fasteners supported thereon, which are then driven through the target tissue and into forming contact with the underside of the anvil 1210. As the firing member 2310 moves distally, a tissue-cutting edge 2314 thereon cuts the stapled tissue.

[0068] After the firing member 2310 is driven distally to an end position within the surgical end effector 1000 ( FIG. 45 ), the rotational drive system 2600 is reversed, causing the firing member 2310 to retract proximally and return to the starting position. Once the firing member 2310 returns to the home or starting position, the anvil spring 1270 pivots the anvil 1210 to an open position, allowing the surgeon to release the stapled tissue from the surgical end effector 1000. Once the stapled tissue has been released, the surgical end effector may be withdrawn from the patient through the trocar cannula. To do so, the surgeon must first actuate the articulation control system 2240 to return the surgical end effector 1000 to a non-articulated position and actuate the rotational drive system to drive the firing member 2310 proximally from the home or starting position to close the jaws. The surgical end effector 1000 may then be withdrawn from the trocar cannula. If the firing system becomes inoperable during the firing or retraction process, the surgeon may retract the firing member 2310 to the starting position by applying a pulling motion to the cables 2404, 2505 in the proximal direction in various manners described herein.

[0069] 46-68 illustrate another surgical instrument 22010 that is in many respects identical to or very similar to the surgical instrument 10 described above, except for various differences discussed below. Like the surgical instrument 10, the surgical instrument 22010 can address many of the challenges faced by surgical instruments having articulatable end effectors configured to cut and fasten tissue. In various embodiments, the surgical instrument 22010 can comprise a handheld device. In other embodiments, the surgical instrument 22010 can comprise an automated system, sometimes referred to as a robotic control system, for example. In various forms, the surgical instrument 22010 comprises a surgical end effector 23000 operably coupled to an elongate shaft assembly 24000. The elongate shaft assembly 24000 can be operably attached to a handheld housing or can otherwise comprise part of a robotic system, as described above.

[0070] As seen in FIG. 49 , in one form, the surgical end effector 23000 includes a first jaw 23100 and a second jaw 23200. In the illustrated device, the first jaw 23100 includes an elongated channel 23110 having a proximal end 23112 and a distal end 23114 and configured to operably support a surgical staple cartridge 1300 therein. The elongated channel 23110 has an open bottom to facilitate ease of assembly and includes a channel cover 23113 configured to be attached (e.g., welded) thereto to cover the opening and add rigidity to the elongated channel 23110. In the illustrated device, the second jaw 23200 includes an anvil 23210 including an elongated anvil body 23212 having a proximal end 23214 and a distal end 23216. In one arrangement, an anvil cover 23213 is provided to facilitate assembly of the device and to add rigidity to the anvil 23210 when the anvil 23210 is attached (e.g., welded) to the anvil body 23212. The anvil body 23212 includes a staple-forming lower surface 23218 facing the first jaw 23100 and may include a series of staple-forming pockets (not shown) corresponding to each of the staples or fasteners in the surgical staple cartridge 1300. The proximal end 23214 of the anvil body 23212 includes an anvil mounting portion 23230 including a pair of laterally extending mounting pins 23232 configured to be received in corresponding mounting or pivot cradles 23120 formed in the proximal end 23112 of the elongated channel 23110. The mounting pin 23232 is pivotally retained within the mounting cradle 23120 by an anvil cap 23260, which may be attached to the proximal end 23112 of the elongated channel 23110 by screws 23261. In other arrangements, the anvil cap 23260 may be attached to the elongated channel 23110 by welding, adhesive, or the like. Such arrangements facilitate pivotal advancement of the anvil 23210 relative to the surgical staple cartridge 1300 mounted within the elongated channel 23110 about a pivot axis PA between an open position ( FIG. 47 ) and a closed position ( FIG. 48 ).Such a pivot axis PA may be referred to herein as "fixed" in that the pivot axis does not translate or otherwise move when the anvil 23210 is pivoted from the open position to the closed position.

[0071] In the illustrated arrangement, the anvil 23210 is moved to the open position by a pair of anvil springs 23270 supported within the proximal end 23112 of the elongate channel 23110. See FIGS. 49 and 62. The springs 23270 are positioned to apply a pivotal biasing force to a corresponding portion of the anvil 23210 to apply an opening force. See FIG. 47.

[0072] In the illustrated device, the elongate shaft assembly 24000 defines a shaft axis SA and comprises a proximal shaft portion 24100 that may be operatively associated with a housing of a control portion of the surgical instrument 22010 (e.g., a handheld unit, a robotic tool driver, etc.). The elongate shaft assembly 24000 further comprises an articulation joint 24200 attached to the proximal shaft portion 24100 and the surgical end effector 23000. In various examples, the proximal shaft portion 24100 comprises a hollow outer tube 24110 that may be operatively coupled to the housing in various manners as described above. As can be seen in FIG. 49 , the proximal shaft portion 24100 may further comprise a rigid proximal support shaft 24120 that is supported within the hollow outer tube 24110 and extends from the housing to the articulation joint 24200. The rigid proximal support shaft 24120 may comprise a first half 24120A and a second half 24120B that may be coupled together by, for example, welding, adhesive, etc. The rigid proximal support shaft 24120 comprises a proximal end 24122 and a distal end 24124 and includes an axial passage 24126 extending therethrough from the proximal end 24122 to the distal end 24124.

[0073] As described above, many surgical end effectors use a firing member that is pushed distally through a surgical staple cartridge by an axially movable firing beam. The firing beam is typically attached to the firing member at a central region of the firing member body. This attachment location can create imbalance in the firing member as it is advanced through the end effector. Such imbalance can lead to undesirable friction between the firing member and the end effector jaws. Creating this additional friction can require the application of higher firing forces to overcome such friction and can cause undesirable wear on portions of the jaws and / or firing member. Applying higher firing forces to the firing beam can result in undesirable bending in the firing beam as it traverses the articulation joint. Such additional bending can cause the articulation joint to de-articulate, particularly when the surgical end effector is articulated at relatively high articulation angles. The surgical instrument 22010 employs a firing system 24300 that is identical in many respects to, or very similar to, the firing system 2300 described above. Therefore, only those aspects of the firing system 24300 that are necessary to understand the operation of the surgical instrument 22010 are discussed below.

[0074] As can be seen in FIGS. 50-54 , in at least one embodiment, the firing system 24300 comprises a firing member 24310 including a vertically extending firing member body 24312 comprising an upper firing member feature 24320 and a lower firing member feature 24350. A tissue-cutting blade 24314 is attached to or formed within the vertically extending firing member body 24312. See FIGS. 50 and 51 . In at least one device, it is desirable for the firing member 24310 to pass through the anvil body 23212 with low friction, high strength, and high stiffness. In the illustrated device, the upper firing member feature 24320 comprises a T-shaped body 24322 having two laterally extending tabs 24323 projecting therefrom and an upper axial passage 24324 extending therethrough. See FIG. 53 . The lower firing member feature 24350 comprises a T-shaped body 24352 having two laterally extending tabs 24353 projecting therefrom and a lower axial passage 24354 extending therethrough. See FIG. 50 . In at least one device, the upper firing member feature 24320 and the lower firing member feature 24350 are integrally formed with the vertically extending firing member body 24312. As seen in FIG. 54 , the anvil body 23212 comprises an axially extending anvil slot 23240 defining two opposed ledges 23241 for slidably receiving the laterally extending tabs 24323 thereon. Similarly, the elongated channel 23110 comprises an axially extending channel slot 23140 defining an axially extending channel ledge 23141 configured to slidably receive the laterally extending tabs 24353 thereon.

[0075] In the illustrated device, the firing system 24300 comprises an upper flexible spine assembly 24400 operably coupled to an upper firing member feature 24320 of a firing member 24310. In at least one embodiment, the upper flexible spine assembly 24400 comprises an upper series 24410 of upper vertebra members 24420 loosely coupled together by an upper flexible coupler member 24440 that extends through each of the upper vertebra members 24420 and is attached to the upper firing member feature 24320.

[0076] 52, each upper vertebra member 24420 is substantially T-shaped when viewed from its end. In one aspect, each upper vertebra member 24420 comprises an upper vertebra body portion 24422 having a proximal end 24424 and a distal end 24428. Each upper vertebra member 24420 further comprises a downwardly extending upper drive feature or upper vertebra member tooth 24450 protruding from the upper vertebra body portion 24422. Each upper vertebra member tooth 24450 has a spiral-shaped proximal upper surface portion 24452 and a spiral-shaped distal upper surface portion 24454. Each proximal end 24424 of the upper vertebra body portion 24422 has an arcuate or slightly concave curved shape, and each distal end 24428 has an arcuate or slightly convex curved shape. When positioned in the upper series 24410, the convex distal end 24428 on one upper vertebra member 24420 contacts and mates with the concave proximal end 24424 on an adjacent upper vertebra member 24420 in the upper series 24410 to maintain the upper vertebra members 24420 in approximate alignment, so that the helical-shaped proximal upper surface portion 24452 and the helical-shaped distal upper surface portion 24454 on each respective upper vertebra member tooth 24450 can be drivingly engaged by the rotational drive screw 2700 in various manners disclosed herein. These curved mating surfaces on the upper vertebra members 24420 allow for better load transfer between them, even when the upper vertebra members 24420 are angled.

[0077] In at least one embodiment, an upper alignment member 24480 is used to aid in aligning the upper vertebra members 24420 in the upper series 24410. In one arrangement, the alignment member 24480 comprises a spring member or metal cable, which may be fabricated from nitinol wire, spring steel, or the like, and may be formed with a distal upper loop end 24482 and two upper leg portions 24484 that extend through corresponding upper passages 24425 in each upper vertebra body portion 24422. An upper flexible coupler member 24440 extends through the upper passages 24429 of each of the upper vertebra members 24420 to attach to the firing member 24310. In particular, the distal end portion 24442 extends through the upper axial passage 24324 in the upper firing member feature 24320 and is secured therein by an upper retention lug 24444. The proximal portion of the upper flexible coupler member 24440 may interface with a corresponding rotating spool or cable management system of various types and designs disclosed herein that functions to pay out and take up the upper flexible coupler member 24440 and maintain a desired amount of tension therein during movement and articulation of the surgical end effector 23000. The cable management system may be motor-powered or manual (such as a ratchet device) to maintain the desired amount of tension in the upper flexible coupler member 24440. The amount of tension in each flexible coupler member may vary depending on the relative positioning of the surgical end effector 23000 with respect to the elongate shaft assembly 24000.

[0078] The firing system 24300 further comprises a lower flexible spine assembly 24500 operably coupled to the lower firing member feature 24350. The lower flexible spine assembly 24500 comprises a lower series 24510 of lower vertebra members 24520 that extend through each of the lower vertebra members 24520 and are loosely coupled together by a lower flexible coupler member 24540 that is attached to the lower firing member feature 24350. As can be seen in FIG. 52 , each lower vertebra member 24520 is substantially T-shaped when viewed from its end. In one aspect, each lower vertebra member 24520 comprises a lower vertebra body portion 24522 having a proximal end 24524 and a distal end 24528. Each lower vertebra member 24520 further comprises an upwardly extending lower drive feature or lower vertebra member tooth 24550 protruding from the lower vertebra body portion 24522. Each lower vertebra member tooth 24550 has a spiral-shaped proximal lower surface portion 24552 and a spiral-shaped distal lower surface portion 24554. The proximal end 24524 of the lower vertebra body portion 24522 has an arcuate or slightly concave curved shape, and each distal end 24528 has an arcuate or slightly convex curved shape. When positioned in the lower series 24510, the convex distal end 24528 on one lower vertebra member 24520 contacts and mates with the concave proximal end 24524 on an adjacent lower vertebra member 24520 in the lower series 24510 to maintain the lower vertebra members 24520 in approximate alignment, so that the helical proximal lower surface portion 24552 and the helical distal lower surface portion 24554 on each respective lower vertebra member tooth 24550 can be drivingly engaged by the rotational drive screw 2700 in various manners disclosed herein. These curved mating surfaces on the lower vertebra members 24520 allow for better load transfer between them, even when the lower vertebra members 24520 are angled.

[0079] In at least one embodiment, a lower alignment member 24580 is used to aid in aligning the lower vertebra members 24520 in the lower series 24510. In one arrangement, the lower alignment member 24580 comprises a spring member or metal cable which may be made from nitinol wire, spring steel, or the like, and may be formed with a distal lower loop end 24582 and two lower leg portions 24584 that extend through corresponding lower passages 24525 in each lower vertebra body portion 24522. A lower flexible coupler member 24540 extends through the lower passage 24529 of each of the lower vertebra members 24520 for attachment to the firing member 24310. In particular, the distal end portion 24542 of the lower flexible coupler member 24540 extends through a lower axial passage 24354 in the lower firing member feature 24350 and is secured therein by a lower retaining lug 24544. The proximal portion of the lower flexible coupler member 24540 may interface with a corresponding rotating spool or cable management system of various types and designs disclosed herein that functions to pay out and take up the lower flexible coupler member 24540 and maintain a desired amount of tension therein during movement and articulation of the surgical end effector 23000. The cable management system may be motor-powered or manually operated (such as a ratchet device) to maintain the desired amount of tension in the lower flexible coupler member 24540. The amount of tension in each flexible coupler member may vary depending on the relative positioning of the surgical end effector 23000 with respect to the elongate shaft assembly 24000.

[0080] According to at least one embodiment, a large surface area is advantageous for distributing forces between the vertebra members as they push so that they cannot twist relative to one another. The available area within the anvil and channel is limited, and the anvil and channel must remain rigid. The T-shaped upper vertebra member 24420 and the T-shaped lower vertebra member 24520 are designed to fit within the limited space available within the anvil 23210 and elongated channel 23110 while ensuring that there is a large area for distributing firing loads. The curved surfaces on each upper vertebra member 24420 and each lower vertebra member 24520 allow each of these vertebrae to better transfer loads between themselves, even when they are angled. The upper alignment member 24480 and the lower alignment member 24580 may also function to prevent the upper vertebra member 24420 and the lower vertebra member 24520 from twisting relative to one another. The large surface area may also help prevent wear on the vertebra members and / or the anvil and channel. The upper flexible spine assembly 24400 and the lower flexible spine assembly 24500 are otherwise operatively associated with the rotary drive screw 2700 apparatus as disclosed herein. The upper flexible coupler member 24440 and the lower flexible coupler member 24540 may also be used in the manner described above to retract the firing member 24310 to its starting position in the event of a failure of the firing drive system 24300 during the firing stroke.

[0081] 51 , the upper firing member feature 24320 on the firing member 24310 includes a distal upper firing member tooth segment 24330 that corresponds to one half of the upper vertebra member teeth 24450 on each upper vertebra member 24420. In addition, two proximal upper firing member teeth 24336 that are identical to the upper vertebra member teeth 24450 on each upper vertebra member 24420 are spaced apart from the distal upper firing member tooth segment 24330. The distal upper firing member tooth segment 24330 and the proximal upper firing member tooth 24336 may each be integrally formed with the upper firing member feature 24320 of the firing member 24310. Similarly, the lower firing member feature 24350 of the firing member 24310 includes a distal lower firing member tooth 24360 and two proximal lower firing member teeth 24366 integrally formed on the lower firing member feature 24350. For example, in at least one device, the firing member 24310, having rigidly attached teeth 24330, 24336, 24360, and 24366, may be fabricated at once as one unitary component using conventional metal injection molding techniques. Those skilled in the art will recognize that the firing member 24310 operates in essentially the same manner as the firing member 2310 described in detail herein.

[0082] 55-58 , according to at least one embodiment, the articulation joint 24200 comprises a mobile exoskeleton assembly 24800. In one form, the mobile exoskeleton assembly 24800 comprises a series 24802 of movably associated annular rib members 24810. As seen in FIGS. 55-57 , each annular rib member 24810 comprises a first or proximal surface 24820 comprising a convex or dome-shaped portion 24822. Each annular rib member 24810 further comprises a second or distal surface 24830 that is concave or dished. Each annular rib member 24810 further comprises an upper spine passage 24840 configured to accommodate passage of the upper flexible spine assembly 24400 therethrough, and a lower spine passage 24842 configured to accommodate passage of the lower flexible spine assembly 24500 therethrough. Additionally, each annular rib member 24810 further includes four articulation passageways 24850, 24852, 24854, and 24856 for accommodating passage therethrough of articulation actuators in the form of articulation cables 24242, 24246, 24250, and 24254. See FIG. 49. Each annular rib member 24810 further includes a central drive passageway 24860 configured to accommodate passage therethrough of a constant velocity (CV) drive shaft assembly 2620.

[0083] 58 , the mobile exoskeleton assembly 24800 comprises a proximal attachment rib 24870 configured to attach the mobile exoskeleton assembly 24800 to the distal end 24124 of the proximal support shaft 24120 by cap screws 24880 or other suitable fastener devices. The proximal attachment rib 24870 comprises a first or distal surface 24872 that is concave or dished to receive or otherwise movably cooperate with the convex or dome-shaped portion 24822 of the proximal surface 24820 of the proximal-most annular rib member 24810P. Similarly, the mobile exoskeleton assembly 24800 comprises a distal attachment rib 24890 configured to attach the mobile exoskeleton assembly 24800 to the proximal end 23112 of the elongate channel 23110 by cap screws 24882 or other suitable fastener devices. The distal mounting rib 24890 includes a first or proximal surface 24892 including a convex or dome-shaped portion 24894 configured to be received within or movably engage the concave or dished distal surface 24832 of the distal-most annular rib member 24810D. In various embodiments, the annular rib members 24810, 24810P, and 24810D may be fabricated from any suitable metal (e.g., stainless steel, titanium, etc.) or other suitable material. The annular rib members 24810, 24810P, and 24810D may be formed by machining or casting, by a suitable drawing or forming operation. The proximal and distal surfaces 24820, 24830 may be polished or otherwise finished to a desired smooth finish to reduce friction and facilitate movement between the annular rib members 24810, 24810P, and 24810D. According to one aspect, all edges on each annular rib member 24810, 24810P, 24810D are rounded to facilitate relative movement between the annular rib members. The proximal attachment rib 24870 and distal attachment rib 24890 may be formed with similar attributes.

[0084] The surgical instrument 22010 also includes an articulation system 24240 configured to impart articulation to the surgical end effector 23000 to articulate the surgical end effector 23000 relative to the elongate shaft assembly 24000. In at least one arrangement, for example, as described above, the articulation system 24240 includes four articulation cables 24242, 24246, 24250, and 24254 extending through the elongate shaft assembly 2400. See FIG. 49 . In the illustrated arrangement, the articulation cables 24242, 24246 pass through the proximal attachment rib 24870, through each of the annular rib members 24810P, 24810, and 24810D, and are secured to the distal attachment rib 24890. For example, in one device, each of the articulation cables 24242, 24246 is secured to the distal attachment rib 24890 by a corresponding attachment lug 24243. See FIGS. 61 and 63. Similarly, the articulation cables 24250 and 24254 extend through the proximal attachment rib 24870 and through each of the annular rib members 24810P, 24810, and 24810D and are secured to the distal attachment rib 24890 by a corresponding attachment lug 24243.

[0085] In one arrangement, each of the articulation cables 24242, 24246, 24250, and 24254 extends through a corresponding coil spring 24896 that is supported within a cavity 24125 in the distal end 24124 of the rigid proximal support shaft 24120. Additionally, each coil spring 24896 is associated with a tensioning lug 24897 that is also journaled on and secured to each respective articulation cable 24242, 24246, 24250, and 24524 to achieve a desired amount of compression in each spring 24896 that serves to hold the annular rib members 24810P, 24810, and 24810D in movably engagement with one another and with the proximal and distal attachment ribs 24870 and 24890. The cables 24242, 24246, 24250, and 24254 are operatively associated with an articulation control system supported within the housing of the surgical instrument 22010. For example, as described above, a proximal portion of each cable 24242, 24246, 24250, and 24254 may be wound onto a corresponding rotating spool or cable management system 2007 ( FIG. 2 ) within the housing portion of the surgical instrument 22010 configured to pay out and retract each cable 24242, 24246, 24250, and 24254 in a desired manner. The spool / cable management system may be motor-powered or manually powered (such as a ratchet device). FIG. 59 illustrates the articulation joint 24200 in a non-articulated position, and FIG. 60 illustrates the articulation joint in one articulated configuration. Such an arrangement allows the surgical end effector 23000 to articulate relative to the elongate shaft assembly 24000 through multiple planes of articulation.

[0086] As seen in FIGS. 49, 58, and 64, the surgical instrument 22010 employs a constant velocity (CV) drive shaft assembly 2620 that spans or extends axially through the articulation joint 24200. The operation and construction of the CV drive shaft assembly 2620 have been described in detail above and will not be repeated here beyond the extent necessary to understand the operation of the surgical instrument 22010. Briefly, as noted above, the CV drive shaft assembly 2620 comprises a proximal CV drive assembly 2630 and a distal CV drive shaft 2670. The proximal CV drive assembly 2630 comprises a proximal shaft segment 2632 comprised of a mounting shaft 2634 configured to be non-rotatably received within a similarly shaped coupler cavity 2616 in the distal end 2614 of the proximal rotational drive shaft 2610. The proximal shaft segment 2632 is in operative association with a series 2640 of movably coupled drive couplings 2650. As seen in FIG. 58 and described above, to ensure that the drive couplings 2650 are engaged with one another, a proximal drive spring 2740 is used to apply an axial biasing force to the series 2640 of drive couplings 2650. For example, as can be seen in FIG. 58 , the proximal drive spring 2740 is disposed between the proximal mounting bushing 2734 and a support flange formed between the distal socket portion 2636 and the proximal barrel portion 2638 of the proximal shaft segment 2632. In one arrangement, the proximal drive spring 2740 may comprise an elastomeric O-ring received on the proximal barrel portion 2638 of the proximal shaft segment 2632. The proximal drive spring 2740 lightly biases the drive couplings 2650 together to reduce any clearance that occurs during articulation. This ensures that the drive couplings 2650 transmit loads torsionally. However, it will be appreciated that in at least one device, the proximal drive spring 2740 does not apply a sufficiently high axial load to create a firing load to translate through the articulation joint 2200.

[0087] To further prevent the drive couplings 2650 from buckling during articulation, the series 2640 of movably coupled drive couplings 2650 extend through at least one low-friction drive cover 24730 that extends through a central drive passage 24860 of each of the annular rib members 24810. In the device shown in FIGS. 63 and 65 , the drive cover 24730 comprises outer and inner cut hypotubes 24732. Such hypotubes 24732 may be made from metal (e.g., stainless steel, etc.) and may have multiple series of cuts or slits therein, which may be made using a laser cutting device. In the illustrated device, the hypotubes 24732 may be fabricated with an upper relief passage 24734 that provides clearance for the upper flexible spine assembly 24400 to pass over during operation while the surgical end effector 23000 is in an articulated position. Additionally, the hypotube 24732 may have a lower relief passage 24736 to provide similar clearance for the lower flexible spine assembly 24500. Also, as seen in FIG. 65, the hypotube 24732 may be molded with diametrically opposed lateral tab portions 24738 to provide lateral stability during articulation. FIG. 66 shows an alternative drive cover 24730' comprising an internally cut hypotube 24732'. FIGS. 58, 67, 68, and 69 illustrate an alternative drive cover 24730'' comprising flexible heat shrink tubing 24732'' applied over the constant speed (CV) drive shaft assembly 2620. In yet other arrangements, the drive cover may also comprise a coil spring or coil member.

[0088] Various embodiments of the present disclosure offer advantages over previous surgical endocutter designs capable of articulation. For example, pushing a firing member forward in an articulating end effector typically requires a significant amount of force that must be balanced. For example, when firing a firing member at angles greater than 60 degrees, it becomes very difficult to push the beam through the articulation joint. The joint also experiences significant loads that can disarticulate the articulation joint. By employing upper and lower flexible drives that are flexible through the articulation joint but become rigid distally to the articulation joint, a large degree of articulation (e.g., articulation angles greater than 70 degrees) can be enabled while applying a balancing load to the firing member that is constrained by the firing member rather than the articulation joint. Stated another way, instead of a longitudinal load that can disarticulate the end effector, a torsional load is applied proximal to the articulation joint. The torsional load is converted into a longitudinal load distal to the articulation joint. Thus, the rotary drive screw functions to actually translate torsional motion or load into a longitudinal load that is applied to the firing member at a location distal to the articulation joint.

[0089] Additionally, by longitudinally disassembling the threaded drive, the threaded drive passes through the articulation joint while also effectively reducing the length of the surgical end effector. For example, each single vertebra tooth is significantly shorter than multiple rigidly connected pitches. The vertebra can angle as it passes through the articulation joint. This flexible interconnection allows the rotary drive screw to be positioned closer to the articulation joint than would be significantly farther away if all of the pitches were rigidly connected.

[0090] 70-73 illustrate another surgical end effector 4000 that may be used with a surgical instrument 3010, which may be similar to surgical instrument 10 in many respects. The surgical end effector 4000 may be similar to the surgical end effector 1000, except for the differences discussed below. The surgical end effector 4000 is operably coupled to an elongate shaft assembly 5000. The elongate shaft assembly 5000 may be operably attached to a housing portion of the surgical instrument 3010. The housing may include a handle configured to be grasped, manipulated, and actuated by a clinician. In other embodiments, the housing may comprise a portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one controlled motion that can be used to actuate the surgical end effectors disclosed herein and their respective equivalents.

[0091] In at least one form, the surgical end effector 4000 includes a first jaw 4100 and a second jaw 4200. In the illustrated device, the first jaw 4100 includes an elongate channel 4110 having a proximal end 4112 and a distal end 4114 and configured to operably support a surgical staple cartridge 1300 therein. In the illustrated device, the second jaw 4200 includes an anvil 4210, which may be similar to the anvil 1210 described above. In the illustrated device, the elongate shaft assembly 5000 includes a proximal shaft segment defining a shaft axis SA and operably associated with a housing of a control portion of the surgical instrument 3010 (e.g., a handheld unit, a robotic tool driver, etc.). The elongate shaft assembly 5000 further includes an articulation joint 5200 attached to the proximal shaft portion and the surgical end effector 4000.

[0092] The elongate shaft assembly 5000 may comprise a distal spine assembly 5010 attached to the proximal end 4112 of the elongate channel 4110 and to the articulation joint 5200. See FIG. 70 . The distal spine assembly 5010 is immovably supported within a distal outer tube segment 5020, which is in operative association with the surgical end effector 4000. The elongate shaft assembly 5000 further includes a proximal spine member (not shown), which is in operative association with the proximal end of the articulation joint 5200 and may be attached to or otherwise operatively associated with the housing of the surgical instrument 3010. A proximal outer tube segment 5030 extends from the articulation joint 5200 back to the housing and is in operative association with the housing.

[0093] The surgical instrument 3010 uses a firing drive system 4300 comprising a firing member 4310 including a vertically extending firing member body 4312 comprising upper and lower firing member features. A tissue-cutting blade 4314 is attached to or formed within the vertically extending firing member body 4312. The firing drive system 4300 comprises a rotary drive nut 4400 configured to rotatably drive a series 4600 of drive components 4610 in operative association with the firing member 4310. The rotary drive nut 4400 comprises a flexible proximal segment 4410 that spans the articulation joint 5200 and a threaded distal segment 4420 distal to the articulation joint 5200. The threaded distal segment 4420 comprises a series of variable pitch threads 4430 having coarse spacing 4432 at a proximal end and tighter spacing 4434 at a distal or exit end. See Figure 72. The threaded rotary drive nut 4400 includes a proximal drive gear 4440 that meshes and cooperates with a distal drive gear 4510 that is attached to a rotary drive shaft 4500. See Figure 70. The rotary drive shaft 4500 may cooperate with a gearbox / motor arrangement supported within the housing of the surgical instrument 3010. Rotation of the rotary drive shaft 4500 rotates the drive nut 4400 about the shaft axis SA.

[0094] The rotary drive nut 4400 includes a proximal segment 4410 and a threaded distal segment 4420. The threaded distal segment 4420 is configured to threadably engage a series 4600 of drive components 4610 located distally of the articulation joint 5200 and loosely tethered together by a flexible tether 4640. In at least one device, for example, each drive component 4610 includes a vertically extending plate member 4612, each including a top end 4614 and a bottom end 4618. The top end 4614 includes an upper thread segment 4616, and the bottom end 4418 includes a lower thread segment 4620. The upper thread segment 4616 and the lower thread segment 4620 are configured to threadably engage with the threads 4430 of the rotary drive nut 4400. The series 4600 of drive components 4610 are configured to flexibly pass through the articulation joint 5200 and into a vertical passage 5012 in the distal spine assembly 5010. Rotation of the rotary drive nut 4400 in a first rotational direction moves the series 4600 of drive components 4610 axially in the distal direction, and rotation of the rotary drive nut 4400 in a second rotational direction moves the series 4600 of drive components 4610 axially in the proximal direction.

[0095] 72 , in at least one device, each drive component 4610 further includes a distally protruding latch feature 4630. Each latch feature 4360 is configured to be releasably received in latching engagement within a latch cavity 4364 formed in the adjacent drive component 4610 immediately distal thereto. When the drive components 4610 are latched together, they form an axially rigid series 4600AR of drive components for applying an axial drive motion to the firing member 5310 to drive the firing member 5310 through the surgical end effector 4000 from a start position to an end position and then from the end position back to the start position. As seen in FIG. 72 , when the drive components 4610 enter the threaded distal segment 4420 of the rotary drive nut 4400, they are loosely coupled together. As the drive component 4610 threadably engages with the fine pitch threads 4430 in the threaded distal segment 4420 of the rotary drive nut 4400, the latch arrangement 4630 is latchingly received within a corresponding latch cavity 4364 in the distally adjacent drive component 4610 to form an axially rigid series 4600AR of the drive component 4610. In one arrangement, the distal-most drive component 4610 may be configured to latchingly engage the firing member 4310 in a similar manner, or in an alternative arrangement, the distal-most drive component may be permanently attached to the firing member 4310.

[0096] In the illustrated example, the drive components 4610 in the series of drive components 4600 are flexibly coupled together so that they can move relative to one another to accommodate the articulation joint and do not require the stiffening and support plates typically required when pushing a firing beam through an articulation joint. When the series of drive components 4610 enter and are drivingly engaged by a threaded distal segment 4420 distal to the articulation joint, the drive components 4610 form a series of axially rigid drive components for driving the firing member 4310 through the surgical end effector 4000. The anvil 4210 can be pivoted to an open position by a spring or other device in various ways disclosed herein and then closed by the firing member 4310 as it is driven distally from a start position to an end position in various manners described herein. Other jaw controls can also be used to control the opening and closing of the jaws.

[0097] 73-76 show another surgical end effector 6000 that employs a drive system 6300 including a series 6600 of flexibly coupled drive components 6610 that can be used to rigidly advance a firing member 6130 across an articulation joint 6200 and through the surgical end effector 6000. The surgical end effector 6000 can include a channel 6010 configured to operably support a surgical staple cartridge (not shown) therein. An anvil 6020 can be pivotally coupled to the channel 6010 and can be moved between open and closed positions by the firing member 6130 or other closure system device. The anvil 6020 can be moved to the open position by a spring or other device in various ways as disclosed herein.

[0098] Referring to FIG. 74 , in at least one device, each drive component 6610 comprises a drive component body 6612 having a proximal face 6614, a distal face 6616, and thread segments 6620 formed on a bottom surface 6618. Each drive component 6610 further comprises a proximally projecting latch feature 6630. Each latch feature 6630 comprises a neck feature 6632 having a spherical latch head 6634 formed at an end thereof. The latch feature 6630 is configured to be movably received within a latch cavity 6336 formed in the adjacent drive component 6610 immediately distal thereto. To facilitate movably mounting the drive components 6610 in a movably inline arrangement, the spherical latch head 6634 is inserted into the latch cavity 6636 through a tapered passage 6338 in the drive component body 6612. The spherical latch head 6634 is sized and shaped relative to the latch cavity 6636 to allow relative movement between the drive components 6610 when positioned as shown in FIG. 74. However, when the drive components are axially aligned such that the distal face 6616 of one drive component 6610 abuts and engages the proximal face 6614 of the drive component immediately distal to it, the drive components 6610 form an axially rigid series 6600AR of drive components that can drive the firing member 6130 through the surgical end effector 6000.

[0099] As seen in FIG. 73 , a flexible rotary drive system 6700 is employed to drive a series 6600 of drive components 6610. In one arrangement, the flexible rotary drive system 6700 comprises a flexible rotary drive shaft 6710 that can pass through the articulation joint 6210 and includes a rotary drive gear 6720 configured to threadably engage a thread segment 6620 on each drive component 6610. The flexible rotary drive shaft 6710 can be rotated by a motor / gear arrangement supported within the housing of the surgical instrument. A portion 6600F of the series 6600 of drive components 6610 proximal to the rotary drive gear 6720 remains flexibly tethered or “floppy.” When the drive components 6610 are threadably engaged by the rotary drive gear 6720, they are driven through a passage within the channel 6010, whereby the drive components form an axially rigid series 6600AR for driving the firing member 6130 through the surgical end effector 6000.

[0100] Torsional loads applied to a firing system component as it traverses the articulation joint are less likely to disarticulate the articulation joint than axial loads. Various embodiments disclosed herein transfer torsional loads to longitudinal loads at a location distal to the articulation joint. Because the longitudinal load is contained within the end effector, disarticulation is prevented. FIG. 77 shows an example of one firing system 6800 that can provide such advantages. The firing system 6800 includes a firing member 6810 configured to be operably supported within a surgical end effector in various ways described herein. A flexible, spring-like driven member 6820 is attached to the firing member 6810. Such a flexible, spring-like driven member 6820 can span an articulation joint region 6840 that can achieve a relatively large range of articulation. The flexible spring-like driven member 6820 is configured to be driven axially by a flexible spring-like torsional drive member 6830 that is rotatably supported to span the articulation joint region 6840. The flexible spring-like torsional drive member 6830 includes a threaded insert 6832 configured to threadably engage the spring-like driven member 6820 at a location 6841 distal to the articulation joint region 6840. The flexible spring-like torsional drive member 6830 may be rotated by a motor / gear arrangement supported within the housing of the surgical instrument. Rotation of the flexible spring-like torsional drive member 6830 in a first direction causes the flexible spring-like driven member 6820 to translate longitudinally, driving the firing member 6810. Rotation of the flexible torsional drive member 6830 in a second direction moves the flexible spring-like driven member proximally.

[0101] 78 shows another firing system 6850 including a firing member 6860 configured to be operably supported within a surgical end effector in various manners described herein. The firing member 6860 is driven by a firing member drive assembly 6861 including a series 6862 of spherical ball members 6870 connected to one another by a flexible cable 6872. Such series 6862 of flexible spherical ball members 6870 can span an articulation joint region 6840 capable of achieving a relatively large range of articulation. The series 6862 of flexible spherical ball members 6870 are configured to be axially driven by a flexible torsional drive member 6880 that is rotatably supported to span an articulation joint region 6890. The flexible torsional drive member 6880 includes an insert 6882 configured to drivingly engage the spherical ball member 6870 at a location 6892 distal to the articulation joint region 6890. The flexible torsional drive member 6880 may be rotated by a motor / gear arrangement supported within the housing of the surgical instrument. Rotation of the flexible torsional drive member 6880 in a first direction drives the spherical ball members 6870 distally into contact with one another and translates longitudinally to form an axially rigid series 6862AR that drives the firing member 6860 distally. Rotation of the flexible torsional drive member 6880 in a second direction moves the series of spherical ball members 6870 proximally.

[0102] FIG. 79 illustrates another firing system 6950 including a firing member 6960 configured to be operably supported within a surgical end effector in various manners described herein. A laser-cut hypotube driven member 6970 is attached to the firing member 6960. Such a flexible driven member 6970 can span an articulation joint region 6940 capable of achieving a relatively large range of articulation. The flexible driven member 6970 is configured to be axially driven by a flexible torsional drive member 6980 that is rotatably supported to span the articulation joint region 6940. The flexible torsional drive member 6980 includes a threaded insert 6982 configured to threadably engage a laser cut 6972 on the flexible driven member 6970 at a location 6942 distal to the articulation joint region 6940. The flexible torsional drive member 6980 can be rotated by a motor / gear arrangement supported within the housing of the surgical instrument. Rotation of the flexible torsional drive member 6980 in a first direction causes the flexible driven member 6970 to translate longitudinally, driving the firing member 6960. Rotation of the flexible torsional drive member 6980 in a second direction moves the flexible driven member 6970 proximally.

[0103] Pushing a firing beam forward in an articulating end effector typically requires a significant amount of force, and such force must be balanced. For example, it is generally difficult to push a firing beam through an articulation joint that is articulated greater than 60 degrees. As the firing beam traverses through the articulation joint, it can apply significant loads on the articulation joint components, which can cause the articulation joint to disarticulate. FIGS. 80-84 show a firing drive system 7300 including a flexible upper drive band 7320 and a flexible lower drive band 7330 attached to a firing member 7310 configured to move between start and end positions within a surgical end effector 7000. As seen in FIGS. 80-82, the flexible upper drive band 7320 includes a plurality of spaced apart upper drive teeth 7322 configured to threadably engage helical threads 7342 on a rotary drive nut 7340. Similarly, the flexible lower drive band 7330 includes a plurality of spaced apart lower drive teeth 7332 configured to threadably engage helical threads 7342 on the rotary drive nut 7340. In at least one arrangement, the flexible upper drive band 7320 and the flexible lower drive band 7330 are formed from a metallic material and are welded or otherwise attached to the firing member 7310. Such an arrangement serves to balance the firing load applied to the firing member 7310.

[0104] The rotary drive nut 7340 is received on a flexible rotary drive shaft 7350 that is centered between the upper flexible drive band 7320 and the lower flexible drive band 7330 and traverses through an articulation joint region generally designated as 7200. The flexible rotary drive shaft 7350 may be rotated by a motor / gear arrangement supported within the housing of the surgical instrument. When the flexible rotary drive shaft 7350 rotates in a first direction, the upper flexible drive band 7320 and the lower flexible drive band 7330 drive the firing member 7310 distally. When the flexible rotary drive shaft 7350 is rotated in a second direction, the upper flexible drive band 7320 and the lower flexible drive band 7330 pull the firing member 7310 proximally. In at least one arrangement, the upper flexible drive band 7320 and the lower flexible drive band 7330 pass through a guide member 7360 that surrounds the rotary drive nut 7340 to prevent the upper flexible drive band 7320 and the lower flexible drive band 7330 from bypassing the rotary drive nut 7340 during actuation of the flexible rotary drive shaft 7350. See FIG.

[0105] In the device shown, the firing member 7310 is configured to move through a surgical end effector 7000 that includes a first jaw 7010 and a second jaw 7030 configured to move relative to the first jaw 7010. In one embodiment, the first jaw 7010 includes an elongated channel 7012 configured to operably support a surgical staple cartridge therein. See FIGS. 80 and 81 . The second jaw 7030 includes an anvil 7032 that is pivotally supported on the elongated channel 7012 and is movable between open and closed positions relative to the elongated channel 7012. As seen in FIG. 82 , in at least one form, the firing member 7310 includes a shape commonly referred to as an “E-beam.” The firing member 7310 comprises a vertically extending firing member body 7312 having a lower foot feature 7314 with two laterally extending tabs 7315 configured to slidably engage the elongated channel 7012 when the firing member is driven axially within the elongated channel. Additionally, a pair of upper tabs 7316 protrude from an upper portion of the firing member body 7312 to engage the anvil 7032 when the firing member 7310 is driven distally through the closed anvil 7032. During the firing stroke, the tabs 7315 and 7316 can serve to space the anvil 7032 relative to the surgical staple cartridge supported within the elongated channel 7012. The firing member body 7312 further comprises a tissue cutting feature 7318. The tabs 7316 can also function to impart a closing motion to the anvil 7032 when the firing member 7310 is moved distally from a start position.

[0106] In the illustrated example, the firing drive system 7300 may also be used to apply an opening and closing motion to the anvil 7032. As seen in FIGS. 80-83 , a closure nut 7370 is threadably received on the flexible rotary drive shaft 7350. The closure nut 7370 includes cam pins 7372 extending laterally from each side of the closure nut 7370 to be received in corresponding cam slots 7036 in the anvil mounting portion 7034 of the anvil 7032. See FIGS. 80 and 81 . Such cam pins 7372 prevent the closure nut 7370 from rotating with the flexible rotary drive shaft 7350 such that rotation of the flexible rotary drive shaft 7350 moves the closure nut 7370 axially. Thus, rotation of the flexible rotary drive shaft 7350 in a first direction moves the closure nut 7370 distally and cams the anvil 7032 from an open position to a closed position. Rotation of the flexible rotatable drive shaft 7350 in a second rotational direction moves the closure nut 7370 proximally and cams the anvil 7032 back to the open position. Alternating rotation of the flexible rotatable drive shaft 7350 can thus allow the surgeon to quickly open and close the anvil 7032, for example, for grasping purposes.

[0107] FIG. 85 shows an alternative firing drive assembly 7302 comprising a flexible upper drive band 7320′ having upper drive teeth 7322′ and a flexible lower drive band 7330′ having lower drive teeth 7332′ formed from a single piece of material, such as metal. The flexible upper drive band 7320′ also includes an upper strength tab 7324′ provided to pass through the anvil 7032 similar to the upper tab 7316 on the firing member 7310, and a lower strength tab 7334 provided to pass through the channel 7012 similar to the tab 7315 on the firing member 7310. FIG. 86 shows an alternative firing drive assembly 7302′ fabricated from two band assemblies 7302A and 7302B laminated together to form a flexible upper drive band 7320″ having upper drive teeth 7322″ and a flexible lower drive band 7330″ having lower drive teeth 7332″. Each band assembly 7302A, 7302B also includes an upper strength tab 7324A'', 7324B'' and a lower strength tab 7334A'', 7334B'', respectively, that is provided to pass through the anvil 7032 and elongated channel 7012.

[0108] The firing drive system 7300 functions to apply a uniform drive motion to the firing member 7310 and can accommodate articulation angles that may be greater than 70 degrees, for example. Additionally, because the rotary drive nut 7340 engages the upper flexible drive band 7320 and the lower flexible drive band 7330 at a location distal to the articulation joint region 7200, linear firing loads are limited to the end effector and do not pass through the articulation joint.

[0109] 87-89 illustrate another form of surgical instrument 9010 that can address many of the challenges faced by surgical instruments employing end effectors articulatable to large angles of articulation and configured to cut and fasten tissue. In various embodiments, the surgical instrument 9010 may comprise a handheld device. In other embodiments, the surgical instrument 9010 may include an automated system, sometimes referred to as a robotic control system, for example. In various forms, the surgical instrument 9010 comprises a surgical end effector 10000 operably coupled to an elongate shaft assembly 12000. The elongate shaft assembly 12000 may be operably attached to a housing. In one embodiment, the housing may comprise a handle configured to be grasped, manipulated, and actuated by a clinician. In other embodiments, the housing may comprise a portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one controlled motion that can be used to actuate the surgical end effectors disclosed herein and their respective equivalents. Additionally, various components may be "housed" or contained within the housing, or various components may be "associated" with the housing. In such instances, the components may not be contained with or directly supported by the housing. For example, the surgical instruments disclosed herein may be used with the various robotic systems, instruments, components, and methods disclosed in U.S. Patent No. 9,072,535, entitled "SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS," which is incorporated herein by reference in its entirety.

[0110] In one form, the surgical end effector 10000 includes a first jaw 10100 and a second jaw 10200. In the illustrated device, the first jaw 10100 includes an elongated channel 10110 having a proximal end 10112 and a distal end 10114 and configured to operably support a surgical staple cartridge 10300 therein. The surgical staple cartridge 10300 includes a cartridge body 10302 having an elongated slot 10304 therein. A plurality of surgical staples or fasteners (not shown) are stored therein on drivers (not shown) arranged in a row on each side of the elongated slot 10304. The drivers are each associated with a corresponding staple cavity 10308 opening through the cartridge deck surface 10306. The surgical staple cartridge 10300 may be replaced after the staples / fasteners have been ejected therefrom. Other embodiments are contemplated wherein the elongate channel 10110 and / or the entire surgical end effector 10000 are disposed of after the surgical staple cartridge 10300 is used.

[0111] In the illustrated device, the second jaw 10200 includes an anvil 10210 including an elongated anvil body 10212 having a proximal end 10214 and a distal end 10216. The anvil body 10212 includes a staple-forming lower surface 10218 facing the first jaw 10100 and may include a series of staple-forming pockets (not shown) corresponding to each of the staples or fasteners in the surgical staple cartridge 10300. The anvil body 10212 may further include a pair of downwardly extending tissue stop features 10220 formed adjacent the proximal end 10214 of the anvil body 10212. One tissue stop feature 10220 extends from each side of the anvil body 10212 such that the distal end 10222 on each tissue stop 10220 corresponds to the proximal-most staple / fastener in the surgical staple cartridge 10300. As the anvil 10200 moves into a closed position on tissue positioned between the lower staple forming surface 10218 of the anvil 10200 and the cartridge deck surface 10306 of the surgical staple cartridge 10300, the tissue contacts the distal end 10222 of the tissue stop 10220, preventing the tissue from moving proximally beyond the proximal-most staple / fastener, thereby ensuring that the severed tissue is also stapled. When the surgical staple cartridge is "fired," as discussed in further detail below, the staples / fasteners supported within each staple cavity are driven out of the staple cavity 10308, through the clamped tissue, and into forming contact with the lower staple forming surface 10218 of the anvil 10200.

[0112] As seen in FIG. 88 , the proximal end 10214 of the anvil body 10212 includes an anvil mounting portion 10230 including a pair of laterally extending mounting pins 10232 configured to be received within corresponding mounting inserts 10130 configured to be retainingly received within mounting cradles 10120 formed in the proximal end 10112 of the elongated channel 10110. The mounting pins 10232 are pivotally received within pivot holes 10132 in the mounting inserts 10130, which are then inserted into their corresponding cradles 10120 and fixedly secured to the elongated channel 10110 by welding, adhesive, a snap fit, or the like. Such an arrangement facilitates pivotal advancement of the anvil 10210 relative to the elongated channel 10110 about a fixed (i.e., non-translating, non-moving) pivot axis PA. See FIG. 87 .

[0113] In the illustrated arrangement, the elongate shaft assembly 12000 defines a shaft axis SA and comprises a hollow outer tube (omitted for clarity) in operative communication with a housing of a control portion of the surgical instrument 9010 (e.g., a handheld unit, a robotic tool driver, etc.). The elongate shaft assembly 12000 further comprises an articulation joint 12200 that can be attached to the hollow outer tube as well as the surgical end effector 10000 to facilitate selective articulation of the surgical end effector 10000 relative to the elongate shaft assembly 12000 in multiple planes of articulation and about multiple articulation axes. In at least one arrangement, for example, the articulation joint 12200 comprises a proximal joint member 12210, a central joint member 12230, and a distal joint member 12250. In one embodiment, the central joint member 12230 is operatively associated with the proximal joint member 12210 such that the central joint member 12230 is selectively articulatable through a first or proximal articulation plane defined by a first or proximal articulation axis AA1 that transverses the shaft axis SA, and in one embodiment, the distal joint member 12250 is operatively associated with the central joint member 12230 such that the distal joint member 12250 is selectively articulatable through a second or distal articulation plane defined by a second or distal articulation axis AA2 that transverses the shaft axis SA and transverses the first or proximal articulation axis AA1.

[0114] 89 and 90, the proximal joint member 12210 includes a proximal joint distal face 12212 defining two spaced apart lateral apex portions 12214, 12216. Apex portion 12214 defines a radial surface 12215, and apex portion 12216 defines a radial surface 12217 (FIG. 90). The central joint member 12230 includes a proximal face 12232 defining two spaced apart lateral proximal apex portions 12234, 12236. Proximal apex portion 12234 defines a radial surface 12235, and apex portion 12236 defines a radial surface 12237. As can be seen in FIG. 89 , the proximal joint surface 12232 of the central joint member 12230 faces the proximal joint distal surface 12212 of the proximal joint member 12210 such that the central joint member 12230 is articulatable through a first articulation plane defined by a first or proximal articulation axis AA1 that extends between the point where the lateral apex portion 12214 on the proximal joint member contacts the proximal apex portion 12234 on the central joint member 12230 and the point where the lateral apex portion 12216 on the proximal joint member 12210 contacts the proximal apex portion 12236 on the central joint member 12230. In one arrangement, the radial surfaces 12215, 12217 on the lateral apex portions 12214, 12216, respectively, and the radial surfaces 12235 and 12237 on the proximal apex portions 12234, 12236, respectively, can act as rocker points / surfaces about which the central joint member 12230 can articulate relative to the proximal joint member 12210. Additionally, the central joint member 12230 includes a proximal first gear tooth segment configured to rotatably mesh with the distal gear segments 12218, 12220 on the proximal joint member 12210. See FIG. 88. In various arrangements, the radial surface 12235 on the central joint member 12230 may be spaced apart from the radial surface 12215 on the proximal joint member 12210, and the radial surface 12237 on the central joint member 12230 may be spaced apart from the radial surface 12217 on the proximal joint member 12210.

[0115] The central joint member 12230 further comprises a central joint distal surface 12240 defining a centrally disposed upper apex portion 12242 forming an upper radial surface 12244 and a lower apex portion 12246 forming a lower radial surface 12248. See FIG. 89. The distal joint member 12250 is attached to the proximal end 10112 of the elongate channel 10110 by a mounting bushing 10150 and comprises a proximal surface 12251 facing or opposite the central joint distal surface 12240 on the central joint member 12230. See FIGS. 89 and 92. 89 and 92, the proximal face 12251 defines a centrally disposed upper apex portion 12252 forming an upper radial surface 12254 configured to face or abut the upper radial surface 12244 on the central coupling member 12230. The proximal face 12251 further defines a centrally disposed lower apex portion 12256 forming a lower radial surface 12258 configured to face or abut the lower radial surface 12248 on the central coupling member 12230. See FIG. 89. The distal coupling member 12250 further comprises an upper gear tooth segment 12253 configured to rotatably mesh with the upper gear tooth segment 12243 on the central coupling member 12230. Additionally, the distal joint member 12250 includes a lower gear tooth segment 12255 configured to rotatably mesh with the lower gear tooth segment 12245 on the central joint member 12230. See FIG.

[0116] The distal joint member 12250 is configured to articulate through a second or distal articulation plane defined by a second or distal articulation axis AA2 that extends between the point where the upper apex portion 12252 on the distal joint member 12250 contacts or faces the upper apex portion 12242 on the central joint member 12230 and the point where the lower apex portion 12256 on the distal joint member 12250 contacts or faces the lower apex portion 12246 on the central joint member 12230. See FIGS. 89 and 92. In one arrangement, the radial surfaces 12254, 12258 on the upper apex portion 12252 and lower apex portion 12256, respectively, of the distal joint member 12250 and the radial surfaces 12244 and 12248 on the upper apex portion 12242 and lower apex portion 12246, respectively, of the central joint member 12230 may act as rocker points / surfaces about which the distal joint member 12250 may articulate relative to the central joint member 12230. However, in an alternative arrangement, the radial surface 12254 on the distal joint member 12250 may be spaced apart from the radial surface 12244 on the central joint member 12230, and the radial surface 12258 on the distal joint member 12250 may be spaced apart from the radial surface 12248 on the central joint member 12230.

[0117] Returning to FIG. 88 , in the depicted example, the articulation joint 12200 is operably controlled by a cable control system 9030 comprising four cables 12510, 12520, 12530, and 12540 extending through the elongate shaft assembly 12000. The cable control system 9030 may be supported within the housing 9020 of the surgical instrument 9010. The cable control system 9030 may comprise multiple cable support members / capstans, pulleys, etc. controlled by one or more corresponding motors controlled by a control circuit portion of the surgical instrument 9010. In various embodiments, the cable control system 9030 is configured to manage the tension (tension) and payout of the cables at precise times during the articulation process. Additionally, in at least one device, the cable control system 9030 is used to control the opening and closing of the anvil 10210, as described in further detail below.

[0118] As seen in FIG. 88 , the cables 12510, 12520, 12530, and 12540 are configured to operatively communicate with a closure system 12600 that is rotatably mounted to the proximal end 10112 of the elongate channel 10110. In at least one arrangement, the closure system 12600 comprises a pulley unit 12610 that includes a first lateral alpha wrap pulley 12620 and a second lateral alpha wrap pulley 12630 interconnected by a central shaft 12640. See FIGS. 93 and 94 . The pulley unit 12610 is rotatably supported within the proximal end 10112 of the elongate channel 10110 by mounting brackets 12710 and 12720. See FIG. 88 . More specifically, the proximal end 10112 of the elongated channel 10110 defines a firing member parking area 10140 that is proximal to the mounting cradle 10120 and is configured to operably support the firing member 12310 when in the starting position. Each mounting bracket 12710, 12720 is mounted within the firing member parking area 10140 on each side of the shaft axis SA to enable the firing member 12310 to be received within the parking area 10140 when the firing member 12310 is in the starting position. The mounting brackets 12710, 12720 may be attached to the proximal end 10112 of the elongated channel 10110 by welding, adhesive, snap features, or the like. The mounting bracket 12710 includes a first shaft cradle 12712 configured to rotatably support a first pivot shaft 12621 protruding from a first lateral alpha wrap pulley 12620, and the second mounting bracket 12720 includes a second shaft cradle 12722 configured to rotatably support a second pivot shaft 12644 protruding from a second lateral alpha wrap pulley 12630. Additionally, each mounting bracket 12710, 12720 further includes a relief area 12732 shaped to receive the corresponding first and second alpha wrap pulleys 12620, 12630 therein.

[0119] 94 , the first alpha wrap pulley 12620 includes a first circumferential groove 12622 and a second circumferential groove 12624. In the illustrated example, the first cable 12510 is received in and attached to the first circumferential groove 12622, and the second cable 12520 is received in and attached to the second circumferential groove 12624. Pulling the first cable 12510 causes the first lateral alpha wrap pulley 12620 to rotate in a first direction, and pulling the second cable 12520 causes the first lateral alpha wrap pulley 12620 to rotate in a second, opposite direction. Similarly, the second lateral alpha wrap pulley 12630 includes a first circumferential groove 12632 and a second circumferential groove 12634. In the illustrated arrangement, the cable 12540 is received within and attached to the first circumferential groove 12632, and the second cable 12520 is received within and attached to the second circumferential groove 12634. Pulling the fourth cable 12540 rotates the first second alpha wrap pulley 12630 in a first direction, and pulling the third cable 12530 rotates the second lateral alpha wrap pulley 12630 in a second, opposite direction. The lateral alpha wrap pulleys 12620, 12630 can rotate approximately 330 degrees. This range of rotational travel is in contrast to typical pulleys, which may have a rotational travel range of less than 180 degrees.

[0120] Each of the first and second lateral alpha wrap pulleys 12620, 12630 also includes a corresponding helical closure cam configured to impart a closing motion to the anvil 10210. As seen in FIG. 94 , the first lateral alpha wrap pulley 12620 includes a first helical closure cam 12626, and the second lateral alpha wrap pulley 12630 has a second helical closure cam 12636 thereon. The helical closure cams 12626, 12636 are configured to cam with and impart a closing motion to a corresponding anvil closure arm 10234 on the anvil mounting portion 10230 of the anvil 10210. FIG. 96 shows the position of the helical closure cam 12626 on the first lateral alpha wrap pulley 12620 when the anvil 10210 is biased to the open position by the anvil spring 10240. As the pulley unit 12610 rotates in a first rotational direction, the helical closure cam 12626 cams the anvil 1210 to the closed position shown in FIG. 97. To open the anvil 10210, the pulley unit 12610 is rotated in the opposite direction, returning it to the position shown in FIG.

[0121] 91 and 93, a first cable 12510 extends from the cable control system through the elongate shaft assembly and through a passage in the proximal joint member 12210 and is looped around two diverting pulleys 12650, 12660 supported on shafts 12602, 12612 mounted in the central joint member 12230. The first cable 12510 exits the central joint member 12230 through a passage 12231 and extends through a passage 12257 in the distal joint member 12250 to be received within and attached to a first circumferential groove 12622 in the first lateral alpha wrap pulley 12620. The second cable 12520 extends from the cable control system, through the elongate shaft assembly, through a passage 12213 in the proximal joint member 12210, and is looped around the diverting pulleys 12650, 12660 in the central joint member 12230. The second cable 12520 exits the central joint member 12230 through a corresponding passage 12241, extends through a passage 12259 in the distal joint member 12250, and is received within and attached to a second circumferential groove 12624 in the first lateral alpha wrap pulley 12620.

[0122] In the illustrated example, a third cable 12530 extends from the cable control system 9030, through the elongate shaft assembly 12000, through corresponding passages in the proximal joint member 12210, the central joint member 12230, and the distal joint member 12250, to be received within and attached to a corresponding circumferential groove in the second lateral alpha wrap pulley 12630. Additionally, a fourth cable 12540 extends from the cable control system 9030, through the elongate shaft assembly 12000, through corresponding passages in the proximal joint member 12210, the central joint member 12230, and the distal joint member 12250, to be received within and attached to a corresponding circumferential groove in the second lateral alpha wrap pulley 12630.

[0123] In at least one example, to articulate the surgical end effector 10000 relative to the elongate shaft assembly 12000 through a first articulation plane defined by the first articulation axis AA1, the cable control system 9030 is actuated to pull the second cable 12520 and the fourth cable 12540 simultaneously, applying an equal amount of tension to each cable 12520 and 12540. Because the cables 12520, 12540 apply equal amounts of tension to both sides of the pulley unit 12610, the pulley unit 12610 does not rotate. However, the pulling action of the cables 12520 and 12540 is transmitted to the surgical end effector 10000 through the articulation joint 12200, resulting in the central joint member 12230 articulating relative to the proximal joint member 12210 about the first articulation axis AA1. See FIGS. 92 and 98 . To articulate the surgical end effector 10000 through a second articulation plane defined by a second articulation axis AA2 that is transverse to the first articulation plane, the cable control system 9030 is actuated to pull the third cable 12530 and the fourth cable 12540 simultaneously, applying an equal amount of tension to each cable 12530, 12540. Because the cables 12530, 12540 apply equal amounts of tension to both sides of the second lateral alpha wrap pulley 12630 of the pulley unit 12610, the pulley unit 12610 does not rotate. However, the pulling action of the cables 12530 and 12540 is transmitted to the surgical end effector 10000 through the articulation joint 12200, resulting in the distal joint member 12250 articulating about the second articulation axis AA2 relative to the central joint member 12230. Please refer to Figures 92 and 99.

[0124] The cable control system 9030 can also be used to control the opening and closing of the anvil 10210 in the following manner: As described above, when the spiral cams 10626 on the first and second lateral alpha wrap pulleys 10620, 10630 are in the position shown in FIG. 96 , the anvil 10210 is biased to the open position by the anvil spring 10240. To close the anvil 10210 from that position, the cable control system 9030 is actuated to pull the first and fourth cables 12510, 12540 simultaneously, applying the same amount of tension to each cable 12510, 12540. These cables 12510, 12540 rotate the pulley unit 12610 to the closed position shown in FIG. 97 , which cams the closure cam 10626 into contact with the anvil closure arm 10234, pivoting the anvil 10210 to the closed position. It will be appreciated that by applying equal amounts of tension to the cables 12510 and 12540, there is an equal amount of tension applied to each side of the articulation joint 12200, and therefore no moment is applied to the central joint member 12230 and / or the distal joint member 12250. See FIG. 91 . Such an arrangement allows for a desired profile of jaw closure. This cable control system 9030 allows for faster closure when the anvil is fully open. The cable control system 9030 can also function as a closure mechanism that generates lower speeds / higher forces to clamp onto tissue. The cable control system 9030 may also not generate backlash commonly associated with other cable control systems, and therefore may be used to control the articulation position of the end effector. As discussed further below, this cable-actuated closure and articulation system does not cross the central or shaft axis of the articulation joint, which provides significant space for the firing drive system 13000.

[0125] The above-described articulation joint 12200 and cable control system 9030 can also facilitate bi-planar articulation, providing additional actuation motion to the surgical end effector 10000 while keeping a central region of the articulation joint 12200 free for other control systems, as described in further detail below. The articulation joint 12200 uses its final degree of freedom to actuate jaw closure of the surgical end effector. In one aspect, the articulation joint 12200 comprises N+1 joints, meaning that for N degrees of freedom, the joint requires N+1 cables to actuate it. Thus, in the example described above, the articulation joint 12200 uses four actuation cables.

[0126] As seen in FIGS. 100-103 , the firing drive system 13000 comprises a firing member 13310 including a vertically extending firing member body 13312 having two laterally extending tabs 13314 protruding from a lower portion 13313 of the firing member body 13312. The tabs 13314 are configured to slidably engage ledges 10113 in the elongated channel 10110 when the firing member 13310 is driven axially within the elongated channel 10110. Additionally, a pair of upper tabs 13316 protrude from an upper portion 13315 of the firing member body 13312. The upper tabs 13316 are configured to engage ledges 10213 ( FIG. 103 ) in the anvil body 10212 when the firing member 13310 is driven distally through the closed anvil 10210. During the firing stroke, the tabs 13314 and 13316 can serve to space the anvil 10210 relative to the surgical staple cartridge supported within the elongated channel 10110. The firing member body 13312 also includes a tissue cutting feature 13318 and a proximally-facing notch 13319 configured to accommodate the central shaft 12640 of the pulley unit 12610 when the firing member 13310 is in its proximal-most starting position within a firing member parking area 10140 in the proximal end 10112 of the elongated channel 10110.

[0127] 100-102, the firing drive system 13000 further includes an upper flexible chain drive assembly 13400 operably coupled to the upper portion 13315 of the firing member 13310, and a lower flexible chain drive assembly 13500 operably coupled to the lower portion 13313 of the firing member 13310. In at least one embodiment, the upper flexible chain drive assembly 13400 includes an upper series 13410 of upper chain link features 13420 loosely coupled together by upper flexible coupler members 13402 attached to the upper portion 13315 of the firing member 13310. In at least one example, each upper chain link feature 13420 includes an upper ball or sphere 13422 having an upper hollow passage 13424 configured to allow the upper flexible coupler member 13402 to pass therethrough. 100 , the upper flexible chain drive assembly 13400 further includes an upper compression assembly 13430 for compressing together the upper balls 13422 of the upper series 13410. In one arrangement, the upper compression assembly 13430 includes a hollow flexible compression tube 13432 received on the upper flexible coupler member 13402. An upper ferrule 13440 is crimped onto the upper flexible coupler member 13402, and an upper compression spring 13442 is journaled between the upper ferrule 13440 and the upper flexible compression tube 13432 to distally bias the upper flexible compression tube 13432 into contact with the proximal-most upper ball 13422P of the upper series 13410 of the upper chain link features 13420.

[0128] Similarly, in at least one embodiment, the lower flexible chain drive assembly 13500 includes a lower series 13510 of lower chain link features 13520 loosely coupled together by a lower flexible coupler member 13502 attached to the lower portion 13313 of the firing member 13310. In at least one example, each lower chain link feature 13520 includes a lower ball or sphere 13522 having a lower hollow passageway 13524 configured to allow the lower flexible coupler member 13502 to pass therethrough. The lower flexible chain drive assembly 13500 further includes an upper compression assembly 13530 for compressing the lower balls 13522 of the lower series 13510 together. In one arrangement, the lower compression assembly 13530 includes a hollow flexible compression tube 13532 received over the lower flexible coupler member 13502. The lower ferrule 13540 is crimped onto the lower flexible coupler member 13502, and a lower compression spring 13542 is journalled between the lower ferrule 13540 and the lower flexible compression tube 13532 to urge the lower flexible compression tube 13532 distally into contact with the proximal-most lower ball 13522P in the lower series 13510 of the lower chain link feature 13520.

[0129] 104 , in at least one device, the firing drive system 13000 further includes a rotary drive screw 13700 configured to be in driving communication with the upper series 13410 of upper chain link features 13420 and the lower series 13510 of lower chain link features 13520. As seen in FIG. 104 , in the illustrated device, the rotary drive screw 13700 is rotatably supported within a mounting bushing 10150 that is attached to the proximal end 10112 of the elongated channel 10110. For example, the rotary drive screw 13700 includes a body portion 13702 having a central shaft 13704 projecting therefrom that is rotatably mounted in a mounting hole 10152 of the mounting bushing 10150. Such an arrangement allows the rotary drive screw 13700 to rotate about a shaft axis SA.

[0130] In the illustrated example, the rotary drive screw 13700 is driven by a rotary drive system 13600 including a proximal rotary drive shaft 13610 rotatably supported within an axial passage 12225 in the proximal coupling member 12210. As can be seen in FIG. 105 , the proximal rotary drive shaft 13610 includes a proximal end 13612 and a distal end 13614. The proximal end 13612 may be coupled to a gearbox / motor arrangement 9050 or other source of rotational motion housed within the housing 9020 of the surgical instrument 9010. Such a source of rotational motion causes the proximal rotary drive shaft 13610 to rotate about a shaft axis SA within the axial passage 12225 in the proximal coupling member 12210. See FIG. 104 . As seen in FIG. 105 , the distal end 13614 of the proximal rotational drive shaft 13610 is movably coupled to a first drive shaft segment 13620. In the illustrated example, the first drive shaft segment 13620 resembles a “dogbone” having a first spherical proximal end 13622 and a first spherical distal end 13624. See FIG. 106 . The first spherical proximal end 13622 is movably pinned within a first distal socket 13616 formed in the distal end 13614 of the proximal rotational drive shaft 13610 by a first proximal pin 13618. The first proximal pin 13618 extends through an arcuate transverse slot 13623 in the first spherical proximal end 13622. Such an arrangement allows the first spherical proximal end 13622 to move in multiple directions within the first distal socket 13616 while remaining attached to the first distal socket 13616. The first spherical distal end 13624 is received in a first proximal socket 13632 within a central bearing housing 13630 that is mounted within the central joint member 12230. The first spherical distal end 13624 is movably pinned within the first proximal socket 13632 by a first distal pin 13634. The first distal pin 13634 extends through an arcuate transverse slot 13625 in the first spherical distal end 13624. Such an arrangement allows the first spherical distal end 13624 to move in multiple directions within the first proximal socket 13632 while remaining attached to the central bearing housing 13630.

[0131] As seen in FIG. 105 , the rotational drive system 13600 further includes a second drive shaft segment 13640 similar to the first drive shaft segment 13620 and including a second spherical proximal end 13642 and a second spherical distal end 13644. The second spherical proximal end 13642 is movably pinned within a second distal socket 13636 formed in the central bearing housing 13630 by a second proximal pin 13637. The second proximal pin 13637 extends through an arcuate transverse slot 13643 in the second spherical proximal end 13642. Such an arrangement allows the second spherical proximal end 13642 to remain attached to the second distal socket 13636 and to move within the second distal socket 13636 in multiple directions. The second spherical distal end 13644 is received within a second proximal socket 13706 in the rotary drive screw 13700 and is movably pinned within the second proximal socket 13706 by a second distal pin 13647. The second distal pin 13647 extends through a transverse slot 13646 in the second spherical distal end 13644. Such an arrangement allows the second spherical distal end 13644 to move in multiple directions relative to the rotary drive screw 13700.

[0132] The double-joint rotary drive maintains linear velocity output by using angular constraints on the joint members of the articulated joint. This universal rotary joint device itself can have a sinusoidal output based on the angle of the joint. When the angles are equal and the phases are precisely aligned, the sinusoidal output of the first universal joint is canceled by the second universal joint, producing a linear rotational velocity. This is advantageous over constraining the rotary drive because it reduces component complexity and prevents the need to remove material from components to achieve the required clearance. Therefore, the components of this embodiment are more robust and powerful than conventional devices. Furthermore, the constant speed of the rotary drive system allows for a smoother firing and reduces wear that could otherwise be caused by vibration.

[0133] 102, the rotary drive screw 13700 includes helical grooves or drive features 13708 formed on its circumference that are configured to engage and drive the upper balls or spheres 13422 in the upper series 13410 of the upper chain link features 13420 and the lower balls or spheres 13522 in the lower series 13510 of the lower chain link features 13520. Thus, to drive the firing member 13310 from a start position within the surgical end effector 10000 to a finish position within the end effector, the rotary drive system 13600 is actuated to impart a rotary drive motion to the rotary drive screw 13700. When the rotary drive screw 13700 rotates in a first rotational direction, the helical drive feature 13708 engages with the upper balls or spheres 13422 in the upper series 13410 of the upper chain link features 13420 and the lower balls or spheres 13522 in the lower series 13510 of the lower chain link features 13520 and drives the upper flexible chain drive assembly 13400 and the lower flexible chain drive assembly 13500 distally. When each upper ball 13422 and lower ball 13522 engages the rotary drive screw 13700, the upper balls 13422 in the upper series 13410 distal to the rotary drive screw 13700 (and articulation joint 12200) and the lower balls 13522 in the lower series 13510 distal to the rotary drive screw 13700 (and articulation joint 12200) are placed under compression to apply a balanced axial driving force to the firing member 13310. When the upper and lower flexible chain drive assemblies 13400 and 13500 are in compression, they are constrained by slots in the anvil 10210 and elongated channel 10110, respectively. Such an arrangement ensures that the upper and lower flexible chain drive assemblies 13400 and 13500 do not buckle when compressed.

[0134] This device allows for two degrees of articulation freedom for several reasons. For example, the upper and lower flexible chain drive assemblies 13400, 13500 can bend freely in both the pitch and yaw axes. Thus, the upper and lower flexible chain drive assemblies 13400, 13500 can assume a variety of configurations that can correspond to the various articulation positions achievable by the articulation joint 12200. As the firing member 13310 moves distally through the surgical end effector 10000 to an end position therein, the rotational drive system 13600 is actuated to impart a second rotational drive motion to the rotary drive screw 13700, rotating the rotary drive screw 13700 in a second rotational direction about the shaft axis. When the rotary drive screw 13700 is rotated in a second rotational direction, the upper and lower flexible chain drive assemblies 13400, 13500 function to retract the firing member 13310 proximally, returning it to a starting position. As the upper and lower flexible chain drive assemblies 13400, 13500 retract the firing member 13310 proximally, a portion of the upper and lower flexible chain drive assemblies 13400, 13500 traverse back through the articulation joint 12200 and into the elongate shaft. Such an arrangement allows the firing member 13310 to translate a long distance without increasing the length of the end effector joint. Additionally, because the rotary drive screw 13700 drivingly engages the upper and lower flexible chain drive assemblies 13400, 13500 at a location distal to the articulation joint 12200, high compressive loads are contained within the surgical end effector 10000 and do not induce moments in the articulation joint 12200. This arrangement can significantly reduce the strength requirements of the articulation joint. See FIG. 104.

[0135] In at least one arrangement, the surgical instrument 9010 may further comprise a cable tensioning system 13800 configured to maintain a desired amount of tension on the upper and lower flexible chain drive assemblies 13400, 13500 as they bend through the articulation joint 12200. Maintaining the upper and lower flexible chain drive assemblies 13400, 13500 under a desired amount of tension as they pass through the articulation joint 12200 can prevent slack from building up in the flexible chain drive assemblies 13400, 13500, which could otherwise undesirably bunch within the articulation joint 12200. FIGS. 111 and 112 show one form of the cable tensioning system 13800 comprising constant force spring devices 13810 and 13820. Such a solution has the advantage of not requiring the length of the flexible chain drive assemblies 13400, 13500 to be conserved.

[0136] An alternative cable management system 13800′ is shown in FIGS. 113 and 114. In this arrangement, the proximal ends of the flexible chain drive assemblies 13400, 13500 are coupled to one another and journaled about a cable management pulley 13840 configured to translate with the firing member 13310. As the firing member 13310 is advanced distally during the firing stroke, the cable management pulley 13840 also translates distally to maintain tension on the flexible chain drive assemblies 13400, 13500. During articulation, the length of one of the flexible chain drive assemblies 13400, 13500 increases and the other decreases. Such an arrangement helps minimize the length of the flexible chain drive assemblies 13400, 13500 required to fully actuate and articulate the surgical end effector 10000.

[0137] One method of using the surgical instrument 9010 may include using the surgical instrument to cut and staple target tissue within a patient using laparoscopic techniques. For example, one or more trocars may be placed through the patient's abdominal wall to provide access to the target tissue within the patient. The surgical end effector 10000 may be inserted through one trocar, and one or more cameras or other surgical instruments may be inserted through the other trocars. To allow the surgical end effector 10000 to pass through the trocar cannula, the surgical end effector 10000 must be positioned in an unarticulated orientation ( FIG. 63 ) and the jaws 10100 and 10200 must be closed. To hold the jaws 10100 in a closed position for insertion purposes, for example, the cable control system 9030 is actuated to simultaneously pull the first cable 12510 and the fourth cable 12540, which rotates the pulley unit 12610 and causes the closure cams 10626, 10636 to contact the anvil closure arm 10234, pivoting the anvil 10210 to the closed position. See FIG. 97 . The cable control system 9030 is deactivated to hold the anvil 10210 in the closed position. Once the surgical end effector 10000 is through the trocar and into the abdomen, the cable control system 9030 is actuated to rotate the pulley unit 12610 in a direction opposite to the position shown in FIG. 96 , allowing the anvil 10210 to be biased open by the anvil spring 10240.

[0138] Once inside the abdomen and before engaging the target tissue, the surgeon may need to articulate the surgical end effector 10000 to a favorable position. The cable control system 9030 may then be actuated to articulate the surgical end effector 10000 in one or more planes relative to the portion of the elongate shaft assembly 12000 received within the cannula of the trocar. Once the surgeon orients the surgical end effector 10000 to the desired position, the cable control system 9030 is deactuated to hold the surgical end effector 10000 in the articulated orientation. The surgeon may then actuate the cable control system 9030 in the manner described above to quickly close the anvil 10210 to grasp tissue between the anvil 10210 and the surgical staple cartridge 10300. This process may be repeated as necessary until the target tissue is properly positioned between the anvil 10210 and the surgical staple cartridge 10300.

[0139] Once the target tissue is positioned between the anvil 10210 and the surgical staple cartridge 10300, the surgeon can actuate the cable control system 9030 to close the anvil 10210 and clamp the target tissue in place. The firing process can then be initiated by actuating the rotational drive system 13600 to drive the firing member 13310 distally from a start position. As the firing member 13310 moves distally, it contacts a sled supported within the surgical staple cartridge 10300 and drives the sled distally through the staple cartridge body. The sled sequentially drives a row of drivers supported within the staple cartridge toward the clamped target tissue. Each driver has one or more surgical staples or fasteners supported thereon, which are then driven through the target tissue and form contact with the underside of the anvil 10210. As the firing member 13310 moves distally, the tissue-cutting edge 13318 thereon cuts the stapled tissue.

[0140] After the firing member 13310 is driven distally to an end position within the surgical end effector 10000, the rotational drive system 13600 is reversed, causing the firing member 13310 to retract proximally back to the starting position. Once the firing member 13310 has returned to the starting position, the cable control system 9030 may be actuated to rotate the pulley unit 12610 back to the open position, where the anvil spring 10240 can pivot the anvil 10210 to the open position, allowing the surgeon to release the stapled tissue from the surgical end effector 10000. Once the stapled tissue is released, the surgical end effector 10000 can be withdrawn from the patient through the trocar cannula. To do so, the surgeon must first actuate the cable control system 9030 to return the surgical end effector 10000 to the non-articulated position and actuate the cable control system 9030 to pivot the anvil 10210 to the closed position, after which the surgical end effector 10000 may be withdrawn from the trocar cannula.

[0141] In previous endocutter devices, the firing member is pushed by a flexible beam. In such devices, the articulation joint must redirect the linear motion of the flexible beam as it enters the articulation joint back to its linear motion as it exits the articulation joint and enters the end effector. Due to the high loads required to push the flexible beam and firing member, the flexible beam typically experiences a large amount of friction as it exits the articulation joint and is redirected linearly into the end effector. This added amount of friction increases the amount of drive force required to drive the firing member from a start position to a finish position within the end effector while the end effector is articulated. Furthermore, as the flexible beam traverses the articulation joint, it can impose articulation disengagement on the articulation joint components. Therefore, the articulation joint components must be sufficiently robust to resist such articulation disengagement.

[0142] Other forms of surgical endocutters use rotational force to drive a firing member through the end effector. Such devices typically use a rotary drive screw housed within a channel that supports a staple cartridge. During use, the threads and tissue exert a large moment on the firing member, which reduces the efficiency of the system and ultimately requires a higher rotational force to actuate the firing member. Due to the location of the cartridge and tissue, it is difficult to locate the rotary drive screw close to the center of such force. It is also difficult to implement threads on the top and bottom of the firing member without increasing the overall diameter of the surgical end effector. The various embodiments described above address many, if not all, of these issues and challenges.

[0143] 115-139 illustrate another form of surgical instrument 25010 that can address many of the challenges faced by surgical instruments that include end effectors that are articulatable through large angles of articulation and configured to cut and fasten tissue. In various embodiments, the surgical instrument 25010 may comprise a handheld device. In other embodiments, the surgical instrument 25010 may include an automated system, sometimes referred to as a robotic control system, for example. In various forms, the surgical instrument 25010 includes a surgical end effector 26000 operably coupled to an elongate shaft assembly 28000. The elongate shaft assembly 28000 may be operably attached to a housing. In one embodiment, the housing may include a handle configured to be grasped, manipulated, and actuated by a clinician. In other embodiments, the housing may comprise a portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one controlled motion that can be used to actuate the surgical end effectors and their respective equivalents disclosed herein. Additionally, various components may be "housed" or included within the housing, or various components may be "associated" with the housing. In such instances, components may not be included with or directly supported by the housing. For example, the surgical instruments disclosed herein may be used with the various robotic systems, instruments, components, and methods disclosed in U.S. Patent No. 9,072,535, entitled "SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS," which is incorporated herein by reference in its entirety.

[0144] In one form, the surgical end effector 26000 includes a first jaw 26100 and a second jaw 26200. In the illustrated device, the first jaw 26100 includes an elongated channel 26110 having a proximal end 26112 and a distal end 26114 and configured to operably support a surgical staple cartridge 10300 therein. Examples of surgical staple cartridges 10300 are described in detail above. The second jaw 26200 includes an anvil 26210 including an elongated anvil body 26212 having a proximal end 26214 and a distal end 26216. The anvil body 26212 includes a staple-forming lower surface 26218 facing the first jaw 26100 and may include a series of staple-forming pockets (not shown) corresponding to each of the staples or fasteners in the surgical staple cartridge 10300. As seen in FIG. 119 , the proximal end 26214 of the anvil body 26212 includes an anvil mounting portion 26230 including a pair of laterally extending mounting pins 26232 configured to be received within corresponding mounting inserts 26130 configured to be retainingly received within mounting cradles 26120 formed in the proximal end 26112 of the elongated channel 26110. The mounting pins 26232 are pivotally received within pivot holes 26132 in the mounting inserts 26130, which are then inserted into their corresponding cradles 26120 and fixedly secured to the elongated channel 26110 by welding, adhesive, a snap fit, or the like. Such an arrangement facilitates pivotal advancement of the anvil 26210 relative to the elongated channel 26110 about a fixed pivot axis PA. See FIG. 115 . As noted above, the term “fixed” when used in this context means that the pivot axis PA does not translate or move relative to the elongated channel 26110.

[0145] In the illustrated device, an elongate shaft assembly 28000 defines a shaft axis SA and includes a shaft spine assembly 28100 received within a hollow outer shaft tube 28102. See FIG. 119. The shaft spine assembly 28100 may be operatively associated with a housing of a control portion of the surgical instrument 25010 (e.g., a handheld unit, a robotic tool driver, etc.) and, in one embodiment, includes a proximal spine segment 28120 and a distal spine segment 28140.

[0146] The elongate shaft assembly 28000 further comprises an articulation joint 28200 that may be attached to the distal spine segment 28140 and the surgical end effector 26000 to facilitate selective articulation of the surgical end effector 26000 relative to the elongate shaft assembly 28000 in a plurality of planes of articulation. Referring now to FIGS. 120-125 , the articulation joint 28200 comprises a series 28202 of movably associated annular disc members 28210. As seen in FIGS. 122 , 123 , and 125 , each annular disc member 28210 comprises a “first” or proximal surface 28220 that includes a centrally located spherical feature or protrusion 28222. Each annular disc member 28210 further comprises a second or distal surface 28230 that includes an annular hub portion 28232 that defines a recessed socket 28234 therein. See FIGS. 122 and 124. Each annular disc member 28210 further has a central shaft passageway 28236 extending therethrough. As seen in FIGS. 120 and 121 , the articulation joint 28200 further comprises a proximal mounting disc assembly 28240 configured to be attached to the distal end of the distal spine segment 28140 by welding, adhesive, or other suitable fastener device. The proximal mounting disc assembly 28240 comprises a distal face 28242 including an annular hub portion 28244 defining a recessed socket 28246 therein. The proximal mounting disc 28240 further has a central shaft passageway 28248 extending therethrough. Also in the illustrated arrangement, an anvil mounting bracket 26240 is configured to be in operative association with the articulation joint 28200. The anvil mounting bracket 26240 is attached to the proximal end 26112 of the elongated channel 26110 of the surgical end effector 26000 by welding, adhesive, or other suitable fastener device and includes a proximal face 26244 having a centrally located spherical feature or protrusion 26246 protruding therefrom. See FIG. 120. The anvil mounting bracket 26240 further includes a central shaft passageway 26248 therethrough.

[0147] In at least one embodiment, the articulation joint further comprises a series 28270 of elastomeric annular spacer members 28280 which serve to space and provide resilient support between each annular disc member 28210. The elastomeric annular spacer members 28280 define spacer openings 28282 such that each elastomeric spacer member 28280 may be journalled on the annular hub portion 28232 of a corresponding annular disc member 28210. Each annular disc member 28210 is journalled on a central elastomeric support or continuum shaft 28300 which is attached to the proximal mounting disc assembly 28240 and the anvil mounting bracket 26240. In one arrangement, the central continuum shaft 28300 is fabricated from an elastomeric material (e.g., rubber, polymer, etc.) and includes a flanged proximal end 28302 and a cylindrical body portion 28304. The cylindrical body portion 28304 includes a series of annular grooves 28306 therein. Each annular groove 28306 corresponds to one of the annular disc members 28210. The annular disc members 28210 and the annular spacer member 28280 are journaled on the central continuum shaft 28300, as shown in FIG. 120 . The flanged proximal end 28302 of the central continuum shaft 28300 is supported within a proximal passage 28249 in the proximal mounting disc 28240. The cylindrical body portion 28304 of the central continuum shaft 28300 extends through the central passage 28236 of each of the annular disc members 28210 of the series 28202 of movably associated annular disc members 28210. Each centrally disposed spherical feature or protrusion 28222 includes an annular key member 28224 configured to be received within a corresponding annular groove 28306 in the central continuum shaft 28300. Such a device may, for example, serve to orient each annular disc member 28210 on the central continuum shaft 28300 at a desired spacing.

[0148] 120 , the proximal-most elastomeric spacer member 28280P is journaled on the annular hub portion 28244 of the proximal mounting disc assembly 28240 so as to be positioned between the proximal-most annular disc member 28210P and the proximal mounting disc 28240. The annular key member 28224 of the proximal-most annular disc member 28210P is received in a corresponding annular groove 28306 in the central continuum shaft 28300, positioning a centrally disposed spherical feature or protrusion 28222 of the proximal-most annular disc member 28210P within a recessed socket 28246 in the annular hub portion 28244 of the proximal mounting disc 28240. 120, another elastomeric spacer member 28280A is journaled on the annular hub portion 28232 of the proximal-most annular disc member 28210P, such that it is positioned between the proximal-most annular disc member 28210P and the next annular disc member 28210A in the series 28202 of movably interlocking annular disc members 28202. The annular key member 28224 of the annular disc member 28210A is received in a corresponding annular groove 28306 in the central continuum shaft 28300 to position a centrally disposed spherical feature or protrusion 28222 of the annular disc member 28210A within a recessed socket 28246 in the annular hub portion 28244 of the proximal mounting disc 28210P. 120, another elastomeric spacer member 28280B is journaled on the annular hub portion 28232 of the annular disc member 28210A so as to be positioned between the next annular disc member 28210B in the series 28202 of movably associated annular disc members 28210. The annular key member 28224 of the annular disc member 28210B is received in a corresponding annular groove 28306 in the central continuum shaft 28300 to position a centrally located spherical feature or protrusion 28222 of the annular disc member 28210B in a recessed socket 28246 in the annular hub portion 28244 of the annular disc member 28210A.Also in this device, another elastomeric spacer member 28280C is journaled on the annular hub portion 28232 of the annular disc member 28210B, such that it is positioned between the distal-most annular disc members 28210C in the series of movably associated annular disc members 28202. The annular key member 28224 of the distal-most annular disc member 28210C is received in a corresponding annular groove 28306 in the central continuum shaft 28300, locating a centrally located spherical feature or protrusion 28222 of the distal-most annular disc member 28210C within a recessed socket 28246 in the annular hub portion 28244 of the annular disc member 28210B. Finally, another elastomeric spacer member 28280D is journaled on the annular hub portion 28232 of the distal-most annular disc member 28210C, such that it is positioned between the anvil mounting bracket 26240 and the distal-most annular disc member 28210C. The annular key member 28224 of a centrally located spherical feature or protrusion 26246 of the anvil mounting bracket 26240 is received in a corresponding annular groove 28306 in the central continuum shaft 28300, positioning the centrally located spherical feature or protrusion 226246 of the anvil mounting bracket 26240 within a recessed socket 28246 in the annular hub portion 28244 of the distal-most annular disc member 28210C.

[0149] In at least one arrangement, the centrally located spherical feature or protrusion 28222 of each of the annular disc members 28210P, 28210A, 28210B, 28210C, as well as the distal spherical feature or protrusion 26246 of the anvil mounting bracket 26240, includes a pair of arcuate pin grooves 28226 therein to limit the pivotal travel of the annular disc members to a range of relative pivotal travel and prevent full relative rotation of the annular disc members 28210 with respect to one another. As seen in FIG. 120 , a corresponding travel-limiting pin member 28227 is press-fit or otherwise attached to each annular hub portion 28232 and is received in the corresponding pin groove 28226 in the centrally located spherical feature or protrusion 28222, 26246.

[0150] 119 , in the illustrated example, the articulation joint 28200 may be operably controlled by an articulation system 28400 comprising four cable assemblies 28410, 28420, 28430, and 28440 extending through the elongate shaft assembly 28000. In one arrangement, the cable assembly 28410 comprises a proximal cable portion 28412 attached to an articulation rod 28414 that is supported for axial movement within a corresponding axial groove in the shaft spine assembly 28100. A distal cable portion 28416 is attached to the articulation rod 28414. The cable assembly 28420 comprises a proximal cable portion 28422 attached to an articulation rod 28424 that is supported for axial movement within a corresponding axial groove in the shaft spine assembly 28100. A distal cable portion 28426 is attached to the articulation rod 28414. The cable assembly 28430 includes a proximal cable portion 28432 attached to an articulation rod 28434 that is supported for axial movement within a corresponding axial groove in the shaft spine assembly 28100. A distal cable portion 28436 is attached to the articulation rod 28434. The cable assembly 28440 includes a proximal cable portion 28442 attached to an articulation rod 28444 that is supported for axial movement within a corresponding axial groove in the shaft spine assembly 28100. A distal cable portion 28446 is attached to the articulation rod 28444.

[0151] The proximal cable portions 28412, 28422, 28432, 28442 may be operatively associated with a portion of a cable control system 25030 supported within or otherwise associated with the housing of the surgical instrument 25010. The cable control system 25030 may comprise multiple cable support members / capstans, pulleys, etc. controlled by one or more corresponding motors controlled by a control circuit portion of the surgical instrument 25010. In various embodiments, the cable control system 25030 is configured to manage cable tension (tension) and payout at precise times during the articulation process. Additionally, in at least one device, the cable control system 25030 may be used to control the opening and closing of the anvil 26210, as described in further detail below.

[0152] 126 , the distal cable portions 28416, 28426, 28436, 28446 are configured to operatively associate with a closure system 28500 that is rotatably mounted to the proximal end 26112 of the elongate channel 26110. As seen in FIG. 126 , the closure system 28500 comprises a pulley unit 28510 that includes a first lateral alpha wrap pulley 28520 and a second lateral alpha wrap pulley 28530 interconnected by a central shaft 28540. The pulley unit 28510 is rotatably supported within the proximal end 26112 of the elongate channel 26110 and retained therein by an anvil mounting bracket 26240 that is attached to the proximal end 26112 of the elongate channel 26110. See FIG. 119 . The anvil mounting bracket 26240 may be attached to the proximal end 26112 of the elongated channel 26110 by welding, adhesive, snap features, etc. The anvil mounting bracket 26240 includes a shaft cradle 26242 configured to rotatably support the central shaft 28540 within the elongated channel 26110. In the illustrated arrangement, a first pivot shaft 28521 projects from the first lateral alpha wrap pulley 28520 and is pivotally supported within a pivot hole 26113 in the proximal end of the elongated channel. Similarly, a second pivot shaft 28531 projects from the second lateral alpha wrap pulley 28530 and is pivotally supported within a pivot hole 26115 in the proximal end 26112 of the elongated channel 26110.

[0153] 126 , the first alpha wrap pulley 28520 includes a first circumferential groove 28522 and a second circumferential groove 28524. In the illustrated example, the first distal cable portion 28416 is received in and attached to the first circumferential groove 28522, and the second distal cable portion 28426 is received in and attached to the second circumferential groove 28524. Pulling on the first distal cable portion 28416 causes the first lateral alpha wrap pulley 28520 to rotate in a first direction, and pulling on the second distal cable portion 28426 causes the first lateral alpha wrap pulley 28520 to rotate in a second, opposite direction. Similarly, the second lateral alpha wrap pulley 28530 includes a first circumferential groove 28532 and a second circumferential groove 28534. In the illustrated device, the distal cable portion 28446 is received within and attached to the first circumferential groove 28532, and the third distal cable portion 28436 is received within and attached to the second circumferential groove 28534. Pulling on the fourth distal cable portion 28446 rotates the second alpha wrap pulley 28530 in a first direction, and pulling on the third distal cable portion 28436 rotates the second lateral alpha wrap pulley 28530 in a second, opposite direction. According to one embodiment, the lateral alpha wrap pulleys 28520, 28530 can rotate approximately 330 degrees. This range of rotational travel is in contrast to typical pulleys, which may have a rotational travel range of less than 180 degrees.

[0154] Each of the first and second lateral alpha wrap pulleys 28520, 28530 also includes a corresponding helical closure cam configured to impart a closing motion to the anvil 26210. As seen in FIG. 126 , the first lateral alpha wrap pulley 28520 includes a first helical closure cam 28526, and the second lateral alpha wrap pulley 28530 has a second helical closure cam 28536 thereon. The helical closure cams 28526, 28536 are configured to cam into and impart a closing motion to a corresponding anvil closure arm 26234 on the anvil mounting portion 26230 of the anvil 26210. See FIG. 119 . When the pulley unit 28510 rotates in a first rotational direction, the helical closure cams 28526, 28536 cam the anvil 26210 into the closed position. To open the anvil 26210, the pulley unit 28510 is rotated in the opposite direction to position the spiral closure cams 28526, 28536 in a position that allows the anvil 26210 to be pivoted open by an anvil spring (not shown).

[0155] In the illustrated arrangement, the proximal mounting disc 28240, the proximal-most annular disc member 28210P, the annular proximal disc members 28210A, 28210B, 28210C, and the anvil mounting bracket 26240 all include a fourth articulation cable passageway 28214 configured to allow passage of each of the distal cable portions 28416, 28426, 28436, and 28446. FIG. 127 shows the articulation rod 28424 that is slidably supported within and moves axially in a corresponding axial groove 28146 in the distal spine segment 28140. Each of the other articulation rods 28414, 28434, 28444 are similarly supported in axial grooves in the distal spine segment 28140 as well as corresponding grooves in the proximal spine segment 28120.

[0156] 119 and 128-130 , the distal cable portion 28416 extends from the articulation rod 28414 through the articulation joint 28200 and is looped around two diverting pulleys 28550, 28560 that are supported on shafts 28502, 28512 that are rotatably mounted within the proximal end 26112 of the elongate channel 26110. The distal cable portion 28416 exits the articulation joint 28200 and is received within and secured to a first circumferential groove 28522 in a first lateral alpha wrap pulley 28520. The distal cable portion 28426 extends from the articulation rod 28424 through the articulation joint 28200 and is looped around the diverting pulleys 28560, 28550 and is received within and secured to the second circumferential groove 28524 in the first lateral alpha wrap pulley 28520.

[0157] In the illustrated example, the distal cable portion 28436 extends from the articulation rod 28434 through the articulation joint 28200 and is received within and secured to a corresponding circumferential groove 28534 in the second lateral alpha wrap pulley 28530. In addition, the distal cable portion 28446 extends from the articulation rod 28444 through the articulation joint 28200 and is received within and secured to a corresponding circumferential groove 28532 in the second lateral alpha wrap pulley 28530.

[0158] In at least one example, to articulate the surgical end effector 26000 relative to the elongate shaft assembly 28000 through a first plane of articulation, the cable control system 25030 is actuated to pull the distal cable portion 28426 and the distal cable portion 28446 simultaneously, applying an equal amount of tension to each distal cable portion 28426, 28446. Because the distal cable portions 28426, 28446 apply equal amounts of tension to both sides of the pulley unit 28510, the pulley unit 28510 does not rotate. However, the pulling motion of the distal cable portions 28426, 28446 is transmitted to the surgical end effector 26000 via the articulation joint 28200, resulting in articulation of the articulation joint 28200 through the first articulation surface. To articulate the surgical end effector 26000 through a second plane of articulation that is transverse to the first plane of articulation, the cable control system 25030 is actuated to pull the distal cable portion 28436 and the distal cable portion 28446 simultaneously, applying an equal amount of tension to each distal cable portion 28436, 28446. Because the distal cable portions 28436, 28446 apply equal amounts of tension to both sides of the second lateral alpha wrap pulley 25830 of the pulley unit 28510, the pulley unit 28510 does not rotate. However, the pulling motion of the distal cable portions 28436, 28446 is transmitted to the surgical end effector 26000 through the articulation joint 28200, resulting in articulation of the articulation joint 28200 in the second plane of articulation.

[0159] The cable control system 25030 can also be used to control the opening and closing of the anvil 26210 in the following manner: As described above, when the helical closure cams 28526 on the first and second lateral alpha wrap pulleys 28520, 28530 are in a first position, the anvil 26210 may be pivoted to an open position by one or more anvil springs (not shown) positioned at the proximal end 26112 of the elongate channel 26110 and arranged to contact the anvil mounting portion 26230 or the anvil closure arm 26234 to pivot the anvil 26210 to the open position. To close the anvil 26210 from that position, the cable control system 25030 is actuated to pull the distal cable portion 28416 and the distal cable portion 28446 simultaneously, with the same amount of tension being applied to each distal cable portion 28416 and 28446. These distal cable portions 28416, 28446 rotate the pulley unit 28510, causing the helical closure cams 28526, 28536 to contact the anvil closure arm 26234 and cam the anvil 26210 into the closed position. It will be appreciated that applying equal amounts of tension to the distal cable portions 28416, 28446 applies equal amounts of tension to each side of the shaft axis SA, thereby applying no moment to the articulation joint 28200. Such an arrangement allows for a desired jaw closure profile. The cable control system 25030 may allow for faster closure when the anvil 26210 is fully open. The cable control system 25030 may also function as a closure mechanism, generating lower speeds / higher forces to clamp onto tissue. The cable control system 25030 may not generate backlash commonly associated with other cable control systems and, therefore, may also be used to control the articulation position of an end effector. The articulation joint 28200 and cable control system 25030 described above can facilitate multi-planar articulation while also providing additional actuation motion to the surgical end effector 26000.

[0160] As described above, many surgical end effectors use a firing member that is pushed distally through a surgical staple cartridge by an axially movable firing beam. The firing beam is typically attached to the firing member at a central region of the firing member body. This attachment location can create imbalance in the firing member as it is advanced through the end effector. Such imbalance can lead to undesirable friction between the firing member and the end effector jaws. Creating this additional friction can require the application of higher firing forces to overcome such friction and can cause undesirable wear on portions of the jaws and / or firing member. The application of higher firing forces to the firing beam can result in undesirable deflection in the firing beam as it traverses the articulation joint. Such additional deflection can cause the articulation joint to de-articulate, especially when the surgical end effector is articulated at relatively high articulation angles. The surgical instrument 25010 uses a firing system 27000 that can address many, but not all, of these issues.

[0161] 133 and 134 , in at least one embodiment, a firing system 27000 comprises a firing member 27100 including a vertically extending firing member body 27112 comprising an upper firing member feature 27120 and a lower firing member feature 27130. A tissue-cutting blade 27114 is attached to or formed within the vertically extending firing member body 27112. In at least one device, the upper firing member feature 27120 comprises an upper tubular body 27122 having an upper axial passageway 27124 extending therethrough. See FIG. 134 . The lower firing member feature 27130 comprises a lower tubular body 27132 having a lower axial passageway 27134 extending therethrough. In at least one device, the upper firing member feature 27120 and the lower firing member feature 27130 are integrally formed with the vertically extending firing member body 27112. In at least one example, the anvil body 26212 includes an axially extending anvil slot having a cross-sectional shape resembling a "keyhole" to accommodate passage of the upper firing member feature 27120 in various manners described herein. Similarly, the elongated channel 26110 includes an axially extending channel slot that also has a keyhole cross-sectional shape to accommodate passage of the lower firing member feature 27130 as described above.

[0162] In the illustrated arrangement, the firing system 27000 includes an upper firing assembly 27200 in operative association with an upper firing member feature 27120. The upper firing assembly 27200 includes an upper flexible outer tube or conduit 27210 having a proximal end 27212 secured to an upper insert 27214 that is immovably mounted to the shaft spine assembly 28100. For example, the upper insert 27214 may be welded to the shaft spine assembly 28100 or may be attached to the shaft spine assembly 28100 by adhesive or other suitable fastening means. The flexible outer tube or conduit 27210 extends through an upper passageway 28216 provided through the proximal mounting disc assembly 28240, the proximal-most annular disc member 28210P, the annular disc members 28210A, 28210B, 28210C, and the anvil mounting bracket 26240. The distal end 27216 of the flexible outer tube or conduit 27210 can be secured to the anvil mounting bracket 26240.

[0163] In the illustrated embodiment, the upper firing assembly 27200 further includes an upper push rod 27220 slidably supported within a corresponding axial passage in the shaft spine assembly 28100. The upper firing assembly 27200 further includes an upper push coil 27230 supported within an inner flexible upper sleeve 27240 that extends through the upper outer flexible tube or conduit 27210. A proximal end 27232 of the upper push coil 27230 and a proximal end 27242 of the inner upper flexible sleeve 27240 abut the distal end 27222 of the upper push rod 27220. The upper push coil 27230 is hollow and may include a coil spring fabricated from nitinol, titanium, stainless steel, or the like. In other devices, the upper push coil 27230 comprises a laser cut "hypotube" that essentially comprises a hollow tubular member with offset laser cuts that allow the hypotube to flex and bend while also being able to transmit axial force or motion. The inner flexible upper sleeve 27240 may be fabricated from a polymer or similar material and may prevent tissue, fluid, and / or debris from entering the upper push coil 27230, which may interfere with its ability to flex and bend during articulation of the surgical end effector relative to the elongate shaft assembly.

[0164] 134 , the distal end 27234 of the upper push coil 27230 and the distal end 27244 of the inner flexible upper sleeve 27240 abut the proximal end 27123 of the upper tubular body 27122 or upper firing member feature 27120. Also in the illustrated device, the upper firing assembly further includes an upper push coil cable 27250 extending through the hollow upper push coil 27230. The upper push coil cable 27250 includes an upper cable proximal end 27252 secured to the distal end 27222 of the upper push rod 27220 and an upper cable distal end 27254 secured within the upper axial passage 27124 in the upper tubular body 27122 of the upper firing member feature 27120 by an upper mounting lug 27256. The upper push coil cable 27250 is held in tension between the upper firing member feature 27120 and the upper push rod 27220, and functions to hold the distal end 27234 of the upper push coil 27230 and the distal end 27244 of the inner flexible upper sleeve 27240 in abutment with the proximal end 27123 of the upper tubular body 27122 of the upper firing member feature 27120, and the proximal end 27232 of the upper push coil 27230 and the proximal end 27242 of the inner flexible upper sleeve 27240 in abutment with the distal end 27222 of the upper push rod 27220.

[0165] In the illustrated example, the firing system 27000 further includes a lower firing assembly 27300 in operative communication with the lower firing member feature 27130. The lower firing assembly 27300 includes a lower flexible outer tube or conduit 27310 having a proximal end 27312 fixed to a lower insert 27314 that is immovably attached to the shaft spine assembly 28100. For example, the lower insert 27314 may be welded to the shaft spine assembly 28100 or may be attached to the shaft spine assembly 28100 by adhesive or other suitable fastening means. A lower flexible outer tube or conduit 27310 extends through lower passages 28218 provided in each of the proximal mounting disc assembly 28240, the proximal-most annular disc member 28210P, the annular disc members 28210A, 28210B, 28210C, and the anvil mounting bracket 26240. A distal end 27316 of the flexible outer tube or conduit 27310 is fixedly attached to the anvil mounting bracket 26240.

[0166] In the illustrated embodiment, the lower firing assembly 27300 further includes a lower push rod 27320 slidably supported within a corresponding axial passage in the shaft spine assembly 28100. The lower firing assembly 27300 further includes a lower push coil 27330 supported within an inner flexible lower sleeve 27340 that extends through the lower flexible outer tube or conduit 27310. A proximal end 27332 of the lower push coil 27330 and a proximal end 27342 of the inner flexible lower sleeve 27340 abut the distal end 27322 of the lower push rod 27320. The lower push coil 27330 is hollow and may include a coil spring fabricated from nitinol, titanium, stainless steel, or the like. In other devices, the lower push coil 27330 comprises a laser cut hypotube that essentially comprises a hollow tubular member with an offset laser cut that allows the hypotube to flex and bend. The inner flexible lower sleeve 27340 may be fabricated from a polymer or similar material and may prevent tissue, fluid, and / or debris from entering the lower push coil 27330, which may hinder its ability to flex during articulation.

[0167] 134 , the distal end 27334 of the lower push coil 27330 as well as the distal end 27344 of the inner flexible lower sleeve 27340 abut the proximal end 27133 of the lower tubular body 27132 of the lower firing member feature 27130. Also in the illustrated arrangement, the lower firing assembly 27300 further includes a lower push coil cable 27350 extending through the hollow lower push coil 27330. The lower push coil cable 27350 includes a lower cable proximal end 27352 secured to the distal end 27322 of the lower push rod 27320 and a lower cable distal end 27354 secured within the lower axial passage 27134 in the lower tubular body 27132 of the lower firing member feature 27130 by a lower mounting lug 27356. The lower push coil cable 27350 is held in tension between the lower firing member feature 27130 and the lower push rod 27320, which functions to hold the distal end 27334 of the lower push coil 27330 and the distal end 27344 of the inner flexible lower sleeve 27340 in abutment with the proximal end 27133 of the lower tubular body 27132 of the lower firing member feature 27130, and the proximal end 27332 of the lower push coil 27330 and the proximal end 27342 of the inner flexible lower sleeve 27340 in abutment with the distal end 27322 of the lower push rod 27320.

[0168] In the illustrated device, the firing system 27000 further includes a differential drive assembly 27400 configured to axially drive the upper firing assembly 27200 and the lower firing assembly 27300. Referring to FIGS. 136-139 , in at least one device, the proximal end 27224 of the upper push rod 27220 is coupled to a first or upper gear rack 27410 of the differential drive assembly 27400. As seen in FIG. 136 , the first or upper gear rack 27410 is slidably supported within an upper proximal axial cavity 28122 in the proximal spine segment 28120. Similarly, the proximal end 27324 of the lower push rod 27320 is coupled to a second or lower gear rack 27420 that is supported for axial movement within a lower proximal axial cavity 28124 in the proximal spine segment 28120. The differential drive assembly 27400 further includes an axially movable carrier member 27430 centered between the first or upper gear rack 27410 and the second or lower gear rack 27420 and supported for axial movement within a proximal axial cavity 28126 in the proximal spine segment 28120. See FIG. 136. With further reference to FIGS. 136-139, the pinion gear 27432 is pivotally pinned to the axially movable carrier member 27430 such that the pinion gear 27432 is in meshing engagement with the first or upper gear rack 27410 and the second or lower gear rack 27420. The axially movable carrier member 27430 is driven axially within the proximal axial cavity 28126 of the proximal spine segment 28120 by the firing drive actuator 27440. See FIG. 137. In one arrangement, the firing drive actuator 27440 comprises a firing drive gear rack 27442 in driving communication with a drive gear 27444 driven by a firing motor 27446, which may be operably supported within or otherwise associated with the housing of the surgical instrument 25010. In other arrangements, the firing drive actuator 27440 may be axially driven distally and proximally by a cylinder arrangement or other suitable actuator in communication therewith.137-139 , the firing drive actuator 27440 may be attached to the axially movable carrier member 27430 by a pair of spaced apart coupler pins 27448 that are attached to the firing drive actuator 27440 and received in corresponding axial slots 27434 in the axially movable carrier member 27430. Such an arrangement allows for some relative axial movement between the firing drive actuator 27440 and the axially movable carrier member 27430. For example, when the firing drive actuator 27440 is driven distally in the distal direction DD, the axially movable carrier member 27430 does not move distally until the coupler pins 27448 reach the distal ends of their corresponding axial slots 27434, at which point the axially movable carrier member 27430 moves distally. Similarly, when the firing drive actuator 27440 is driven in the proximal direction PD, the axially movable carrier member 27430 does not move proximally until the coupler pins 27448 reach the proximal ends of their corresponding axial slots 27434, at which point the axially movable carrier member 27430 moves proximally.

[0169] Surgical stapling devices require the application of high forces to a firing member over long displacements to form staples and cut tissue. Transmitting that force through an articulation joint is particularly challenging due to the difficulty in redirecting the force in the desired direction and withstanding the loads applied thereto. The differential drive assembly 27400 described herein addresses and solves many, if not all, of these challenges by employing two flexible outer tubes or conduits 27210, 27310 to constrain the paths of the flexible push coils 27230, 27330, respectively. As described herein, the upper flexible outer tube or conduit 27210 surrounds a portion of the upper push coil 27230, and the upper flexible outer tube or conduit 27310 surrounds a portion of the lower push coil 27330. Each of the outer tubes or conduits 27210, 27310 is capable of bending, but they are also capable of solving axial tensile loads. The ability to bend allows the firing member force to be redirected through the articulation joint, and the ability to relieve tension allows it to change the direction the push coil travels. When the push coil 27230, 27330 is placed in compression, the flexible outer tube or conduit 27210, 27310 is placed in tension. The outer tube or conduit 27210, 27310 prevents the push coil 27230, 27330 from buckling. The outer tube 27210, 27310 is terminated to relieve the tensile load. As described above, both the distal end 27216 of the flexible outer tube or conduit 27210 and the distal end 27316 of the flexible outer tube or conduit 27310 are fixedly attached to the anvil mounting bracket 26240. The proximal end 27212 of the flexible outer tube or conduit 27210 and the proximal end 27312 of the flexible outer tube or conduit 27310 are both fixedly attached to the shaft spine assembly 28100.The pinion gear 27432 is in meshing engagement with the first or upper gear rack 27410 and the second or lower gear rack 27420 such that axial movement of one of the first or upper gear rack 27410 and the second or lower gear rack 27420 in one direction causes axial movement of the other of the racks 27410, 27420 in the opposite direction. As seen in FIGS. 138 and 139 , during articulation, as the pinion gear 27432 rotates, the flexible outer tubes or conduits 27210, 27310 can move to account for changes in path length. However, when the firing drive actuator 27440 is driven in the distal direction DD, the axially movable carrier member 27430 is actuated, pushing the push coils 27230, 27330 distally through the outer tubes or conduits 27210, 27310 and firing the tensile loads within the two flexible outer tubes or conduits 27210, 27310 (i.e., driving the firing members 27100 distally), which react against each other without any movement of the pinion gear 27432.

[0170] According to one general aspect, the upper passageway 28216 forms an upper pathway 28221 ( FIG. 117 ) through the articulation joint 28200. Similarly, the lower passageway 28218 forms a lower pathway 28223 through the articulation joint 28200. When the surgical end effector 26000 is in a non-articulated position (i.e., the surgical end effector is axially aligned with the elongate shaft assembly 28000 on the shaft axis SA— FIGS. 115 , 117 , 118 ), the upper pathway 28221 and the lower pathway 28223 are parallel to one another. See FIG. 117 . When the surgical end effector 26000 is in an articulated position relative to the elongate shaft assembly 28000, the upper pathway 28221 and the lower pathway 28223 are concentric with one another. See FIG. 116 .

[0171] When the surgical end effector 26000 is in a non-articulated position, the firing system 27000 can be actuated to drive the firing member 27100 from a starting position within the proximal end 26112 of the elongate channel 26100 to a finishing position within the distal end 26114 of the elongate channel 26110. When the surgical end effector 26000 is in a non-articulated position and the firing system 27000 is actuated, the differential drive assembly 27400 drives the upper firing assembly 27200 and the lower firing assembly 27300 in the same axial direction (i.e., in the distal direction DD) an equal axial distance to impart upper and lower axial drive motions to the firing member 27100. The upper and lower axial drive motions are substantially equal in magnitude, which serves to advance the firing member 27100 distally through the surgical end effector 26000 without coupling that could otherwise occur if the upper and lower axial drive motions were unequal in magnitude. Similarly, when the surgical end effector 26000 is in an articulated position relative to the elongate shaft assembly 28000, the firing system 27000 can be actuated to drive the firing member 27100 from a start position to a finish position. In such a case, the differential drive assembly 27400 is configured to allow the upper and lower firing assemblies 27200 and 27300 to move substantially equal distances in opposite axial directions to correspond to the articulated position. The differential drive assembly 27400 can then apply equal upper and lower axial drive motions to the firing member 27100. For example, depending on the articulated position of the surgical end effector 26000 relative to the elongate shaft assembly 28000, the upper firing assembly 27200 may be moved proximally a first distance upon articulation of the surgical end effector 26000, and the lower firing assembly 27300 may be positioned distally relative to the surgical end effector 26000 a second distance substantially equal to the first distance by the pinion gear 27432. Thereafter, distal actuation of the firing drive actuator 27440 causes the upper firing assembly 27200 and the lower firing assembly 27300 to impart equal upper and lower axial drive motions to the firing member 27100.As used herein, when the carrier is moved distally, the carrier can impart an "axial control motion" to the upper firing assembly 27200 and the lower firing assembly 27300. Thus, when the surgical end effector 26000 is in an unarticulated configuration, the carrier may impart an equal amount of axial control motion to the upper firing member 27200 and the lower firing member 27300 in the same axial direction (distal direction DD), and when the surgical end effector 26000 is in an articulated configuration, the carrier may impart an "other equal amount" of axial control motion to the upper firing member 27200 and the lower firing member 27300 in the same axial direction (distal direction DD) to move the firing member 27100 from a start position to an end position.

[0172] Example 1 - A surgical instrument comprising a surgical end effector, the surgical end effector comprising a firing member supported for axial advancement within the surgical end effector between a start position and an end position. The surgical instrument further comprises an elongate shaft coupled to the surgical end effector by an articulation joint configured to facilitate selective articulation of the surgical end effector relative to the elongate shaft. The articulation joint is configured to establish upper and lower pathways therethrough. When the surgical end effector is in a non-articulated position, the upper and lower pathways are parallel to one another, and when the surgical end effector is articulated relative to the elongate shaft assembly, the upper and lower pathways are concentric with one another. The surgical instrument further comprises a firing system configured to selectively move the firing member between the start position and the end position. The firing system comprises an upper flexible firing assembly slidably extending through the upper pathway and operatively associated with an upper portion of the firing member. A lower flexible firing assembly slidably extends through the lower passageway and is in operative association with a lower portion of the firing member. The firing system further includes a differential drive assembly supported proximally of the articulation joint and in operative association with the upper and lower firing assemblies such that when the surgical end effector is in a non-articulated position, the differential drive assembly is configured to drive the upper and lower flexible firing assemblies in the same axial direction and equal axial distances to impart equal upper and lower axial drive motions to the firing member. When the surgical end effector is in an articulated position, the differential drive assembly is configured to allow the upper and lower firing assemblies to move in equal but opposite axial directions and impart upper and lower axial drive motions to the firing member.

[0173] The surgical instrument of Example 1, wherein the differential drive assembly includes an axially movable carrier assembly operatively associated with the upper and lower flexible firing assemblies, such that when the surgical end effector is in a non-articulated position relative to the elongate shaft assembly, the axially movable carrier assembly simultaneously applies equal amounts of axial control motion in the same axial direction to the upper and lower flexible firing assemblies to move the firing member from the start position to the end position. When the surgical end effector is in an articulated position relative to the elongate shaft assembly, the axially movable carrier assembly simultaneously applies equal amounts of axial control motion in the same axial direction to the upper and lower flexible firing assemblies to move the firing member from the start position to the end position.

[0174] Example 3 - The surgical instrument of Example 2, wherein the proximal end portion of the upper firing assembly comprises a first gear rack and the proximal end portion of the lower firing assembly comprises a second gear rack. The axially movable carrier assembly comprises an axially movable carrier member supported for axial advancement relative to the first gear rack and the second gear rack, and comprises a rotatable pinion gear in meshing engagement with the first gear rack and the second gear rack.

[0175] Example 4 - The surgical instrument of example 3, wherein the axially movable carrier member comprises a carrier rack in meshing engagement with a motor-driven drive gear.

[0176] Example 5 - The surgical instrument of Example 4, wherein the upper flexible firing assembly further comprises an upper flexible coil member having an upper coil distal end and an upper coil proximal end. The upper coil distal end is operatively associated with an upper portion of the firing member, the upper coil proximal end being coupled to the upper gear rack. The lower flexible firing assembly further comprises a lower flexible coil member having a lower coil distal end and a lower coil proximal end. The lower coil distal end is operatively associated with a lower portion of the firing member, the lower coil proximal end being coupled to the lower gear rack.

[0177] Example 6 - The surgical instrument of Example 5, further comprising an upper cable extending through the upper flexible coil member and comprising an upper cable distal end and an upper cable proximal end. The upper cable distal end is coupled to an upper portion of the firing member, and the upper cable proximal end is operatively associated with a source of articulation. The surgical instrument further comprises a lower cable extending through the lower flexible coil member and comprising a lower cable distal end and a lower cable proximal end. The lower cable distal end is coupled to a lower portion of the firing member. The lower cable proximal end is operatively associated with a source of articulation.

[0178] Example 7 - The surgical instrument of Examples 1, 2, 3, 4, 5, or 6, wherein the articulation joint comprises a series of movably associated annular disc members. Each annular disc member comprises a first surface and a second surface. The first surface of one annular disc member is configured to movably associate with the second surface of an adjacent annular disc member to facilitate relative movement in multiple directions between the first and second surfaces. Each annular disc member has an upper opening extending therethrough, such that the upper openings of each annular disc member in the series of movably associated annular disc members cooperate to form an upper passageway for receiving an upper flexible firing assembly therethrough. Each annular disc member further has a lower opening extending therethrough, such that the lower openings of each annular disc member in the series of movably associated annular disc members cooperate to form a lower passageway for receiving a lower flexible firing assembly therethrough.

[0179] Example 8 - The surgical instrument of example 7, wherein the first surface of each annular disc member includes a centrally disposed spherical feature. The second surface of each annular disc member includes a centrally disposed spherical socket configured to movably receive therein a centrally disposed spherical feature of an adjacent annular disc member.

[0180] Example 9 - The surgical instrument of Example 8, further comprising means for limiting the pivotal travel of the centrally disposed spherical feature within the centrally disposed spherical socket of the adjacent annular disc member to a predetermined range of pivotal travel.

[0181] Example 10 - The surgical instrument of Examples 7, 8, or 9, further comprising a resilient spacer member between each annular disc member.

[0182] Example 11 - A surgical instrument as described in Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the surgical end effector comprises a first jaw and a second jaw supported for movably progressing relative to the first jaw between an open position and a closed position.

[0183] Example 12 - The surgical instrument of Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, further comprising a plurality of actuation cables configured to impart articulation to the surgical end effector to articulate the surgical end effector relative to the elongate shaft assembly.

[0184] Example 13 - A surgical instrument as described in Example 12, wherein the plurality of actuation cables are configured to apply an opening motion to the surgical end effector to move the second jaw between an open position and a closed position.

[0185] Example 14 - A surgical instrument comprising a surgical end effector including a channel configured to operably support a surgical staple cartridge therein. The surgical end effector further comprises an anvil pivotally supported on the channel for movement between an open position and a closed position relative to the surgical staple cartridge supported in the channel. A tissue-cutting member is supported for axial advancement within the surgical end effector between a start position and an end position. The surgical instrument further comprises an elongate shaft assembly coupled to the channel by an articulation joint configured to facilitate selective articulation of the surgical end effector relative to the elongate shaft assembly. The articulation joint is configured to establish upper and lower pathways therethrough. When the surgical end effector is in a non-articulated position, the upper and lower pathways are parallel to one another, and when the surgical end effector is articulated relative to the elongate shaft assembly, the upper and lower pathways are concentric with one another. A firing system is configured to selectively move the tissue-cutting member between the start position and the end position. The firing system includes an upper flexible coil member extending through the upper passage and including an upper coil proximal end and an upper coil distal end. The upper coil distal end is coupled to an upper portion of the tissue-cutting member. The firing system further includes a lower flexible coil member extending through the lower passage and including a lower coil proximal end and a lower coil distal end. The lower coil distal end is coupled to a lower portion of the tissue-cutting member. A differential drive assembly is supported proximal to the articulation joint and is in operative association with the upper and lower flexible coil members such that when the surgical end effector is in a non-articulated position, the differential drive assembly is configured to drive the upper and lower flexible coil members in the same axial direction and equal axial distances to impart equal upper and lower axial drive motions to the tissue-cutting member.When the surgical end effector is in an articulated position, the differential drive assembly is configured to allow the upper and lower flexible coil member assemblies to move in equal but opposite axial directions and to impart upper and lower axial drive motions to the tissue-cutting member.

[0186] Example 15 - The surgical instrument of Example 14, further comprising an upper axial push rod having an upper push rod proximal end operatively associated with the differential drive assembly and an upper push rod distal end operatively associated with the upper coil proximal end. The upper push coil cable extends through the upper flexible coil member and comprises an upper cable distal end coupled to an upper portion of the tissue cutting member and an upper cable proximal end coupled to the upper push rod distal end. The surgical instrument further comprises a lower axial push rod having a lower push rod proximal end operatively associated with the differential drive assembly and a lower push rod distal end operatively associated with the lower coil proximal end. The lower push coil cable extends through the lower flexible coil member and comprises a lower cable distal end coupled to a lower portion of the tissue cutting member and a lower cable proximal end coupled to the lower push rod distal end.

[0187] Example 16 - The surgical instrument of Example 15, wherein the upper flexible coil member and a portion of the upper axial push rod are supported within the upper passage and are constrained for axial movement within an upper outer tubular member, the upper outer tubular member having an upper tubular member distal end supported within the surgical end effector and an upper tubular member proximal end fixed within the elongate shaft assembly, and the lower flexible coil member and a portion of the lower axial push rod are supported within the lower passage and are constrained for axial movement within a lower outer tubular member, the lower outer tubular member having a lower tubular member distal end supported within the surgical end effector and a lower tubular member proximal end fixed within the elongate shaft assembly.

[0188] Example 17 - The surgical instrument of Examples 15 or 16, wherein the differential drive assembly comprises an upper gear rack coupled to a proximal end of the upper push rod and a lower gear rack coupled to a proximal end of the lower push rod. A carrier is supported for axial movement relative to the upper and lower gear racks. The carrier comprises a rotatable pinion gear in meshing engagement with the upper and lower gear racks.

[0189] Example 18 - The surgical instrument of Example 17, wherein the carrier further comprises a carrier rack that meshingly engages the motor-driven drive gear.

[0190] Example 19 - A surgical instrument as described in Examples 14, 15, 16, 17, or 18, further comprising a plurality of actuation cables extending through the elongate shaft assembly and the articulation joint to provide actuation motion to the surgical end effector.

[0191] Example 20 - A surgical instrument as described in Example 19, wherein the plurality of actuation cables are configured to impart articulation motion to the surgical end effector for articulation relative to the elongate shaft assembly and to impart opening and closing motion to the anvil.

[0192] The term “control circuitry,” as used in any aspect of the present specification, may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more individual instruction processing cores, a processing unit, a processor, a microcontroller, a microcontroller unit, a controller, a digital signal processor (DSP), a programmable logic device (PLD), a programmable logic array (PLA), or a field programmable gate array (FPGA)), a state machine circuit, firmware that stores instructions executed by the programmable circuitry, and any combination thereof. Control circuitry may be embodied collectively or individually as circuitry that forms part of a larger system, such as, for example, an integrated circuit (IC), an application specific integrated circuit (ASIC), a system on a chip (SoC), a desktop computer, a laptop computer, a tablet computer, a server, a smartphone, etc. Thus, as used herein, "control circuitry" includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application-specific integrated circuit, electrical circuitry forming a general-purpose computing device configured by a computer program (e.g., a general-purpose computer configured by a computer program that at least partially executes the processes and / or apparatus described herein, or a microprocessor configured by a computer program that at least partially executes the processes and / or apparatus described herein), electrical circuitry forming a memory device (e.g., a form of random access memory), and / or electrical circuitry forming a communications device (e.g., a modem, a communications switch, or an optical-to-electrical facility). Those skilled in the art will recognize that the subject matter described herein may be implemented in analog or digital form, or some combination thereof.

[0193] While several embodiments have been shown and described, it is not the applicant's intention to restrict or limit the scope of the appended claims to such details. Numerous modifications, variations, changes, substitutions, combinations, and equivalents of these embodiments may be implemented and will occur to those skilled in the art without departing from the scope of the present disclosure. Moreover, the structure of each element associated with the described embodiments can alternatively be described as a means for providing the function performed by that element. Also, although materials are disclosed with respect to particular components, other materials may be used. It is therefore to be understood that the above description and the appended claims are intended to cover all such modifications, combinations, and variations as fall within the scope of the disclosed embodiments. The appended claims are intended to cover all such modifications, variations, changes, substitutions, modifications, and equivalents.

[0194] One or more components may be referred to herein as being "configured to," "configurable to," "operable / operative to," "adaptable," "capable to," "conformable / conformed to," etc. Those skilled in the art will understand that "configured to" may generally encompass active components and / or inactive components and / or standby components, unless the context requires otherwise.

[0195] Those skilled in the art will understand that the terms used herein generally, and in the appended claims in particular (e.g., the body of the appended claims), are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). Furthermore, those skilled in the art will understand that where a specific number is intended in an introduced claim recitation, such intention will be clearly recited in the claim; and, in the absence of such recitation, no such intention exists. For example, as an aid to understanding, the appended claims below may include the introductory phrases “at least one” and “one or more” to introduce the claim recitation. However, the use of such phrases should not be construed as suggesting that when a claim is introduced by the indefinite article "a" or "an," any particular claim containing such introduced claim language is limited to claims containing only one such recitation, even if the same claim contains an introductory phrase such as "one or more" or "at least one" and the indefinite article "a" or "an" (e.g., "a" and / or "an" should normally be construed to mean "at least one" or "one or more"). The same applies when a definite article is used to introduce a claim.

[0196] Additionally, even when a specific number is explicitly stated in an introduced claim, those skilled in the art will recognize that such a statement should typically be interpreted to mean at least the recited number (e.g., a statement simply stating "two items" without other modifiers generally means at least two items, or two or more items). Furthermore, when notation similar to "at least one of A, B, and C, etc." is used, such syntax is generally intended in the sense that one skilled in the art would understand the notation (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, systems having only A, only B, only C, both A and B, both A and C, both B and C, and / or all of A, B, and C, etc.). When notation similar to "at least one of A, B, or C, etc." is used, such syntax is generally intended in the sense that one of ordinary skill in the art would understand the notation (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, systems having only A, only B, only C, both A and B, both A and C, both B and C, and / or all of A, B, and C, etc.). Furthermore, one of ordinary skill in the art will understand that any disjunctive word and / or phrase presenting two or more alternative terms should typically be understood, whether in the specification, claims, or drawings, to contemplate the possibility of including one of those terms, either of those terms, or both of those terms, unless the context requires otherwise. For example, the phrase "A or B" will typically be understood to include the possibilities of "A" or "B" or "A and B."

[0197] With respect to the appended claims, those skilled in the art will understand that the recited operations herein generally can be performed in any order. Also, while flow diagrams of various operations are shown in a sequence, it should be understood that the various operations may be performed in orders other than those shown, or may be performed simultaneously. Examples of such alternative orderings may include overlapping, interleaved, interrupted, reordered, incremental, preliminary, additional, simultaneous, reverse, or other different orderings, unless the context requires otherwise. Furthermore, terms such as "responsive to," "related to," or other past-tense adjectives are generally not intended to exclude such variations, unless the context requires otherwise.

[0198] It is worth noting that any reference to "one embodiment," "embodiment," "exemplary," "one illustrative embodiment," etc. means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," "exemplary," and "in one illustrative embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0199] Any patent application, patent, non-patent publication, or other disclosure material referenced herein and / or listed in any Application Data Sheet is incorporated herein by reference to the extent the incorporated material is not inconsistent with this specification. As such, and to the extent necessary, the disclosure material explicitly set forth herein shall supersede any conflicting statements incorporated herein by reference. Any material, or portions thereof, that is said to be incorporated herein by reference but that conflicts with current definitions, views, or other disclosure material set forth herein shall be incorporated only to the extent that no conflict arises between the incorporated material and the current disclosure material.

[0200] In summary, many benefits have been described that result from using the concepts described herein. The foregoing description of one or more embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to be limited to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more embodiments have been selected and described to illustrate the principles and practical applications, thereby enabling those skilled in the art to utilize various embodiments, with various modifications, as suited to the particular use contemplated. It is intended that the claims presented herewith define the overall scope.

[0201] While the surgical instrument systems described herein have been described in connection with deploying and deforming staples, however, the embodiments described herein are not limited thereto. Various embodiments are contemplated that deploy fasteners other than staples, such as clamps or tacks. Furthermore, various embodiments are contemplated that utilize any suitable means for sealing tissue. For example, end effectors according to various embodiments may include electrodes configured to heat and seal tissue. Also, for example, end effectors according to certain embodiments may apply vibrational energy to seal tissue.

[0202] Many of the surgical tool systems described herein are driven by electric motors. However, the surgical tool systems described herein can be driven in any suitable manner. In various instances, the surgical tool systems described herein can be driven, for example, by a manually operated trigger. In certain examples, the motors disclosed herein can comprise one or more portions of a robotically controlled system. Furthermore, any of the end effectors and / or tool assemblies disclosed herein can be utilized with robotic surgical tool systems. For example, U.S. Patent Application No. 13 / 118,241, entitled "SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS" (U.S. Patent No. 9,072,535), discloses several examples of robotic surgical tool systems in more detail.

[0203] The entire contents of the following disclosures are incorporated herein by reference. U.S. Patent No. 5,403,312, issued April 4, 1995, entitled "ELECTROSURGICAL HEMOSTATIC DEVICE"; U.S. Patent No. 7,000,818, issued February 21, 2006, entitled "SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCT CLOSING AND FIRING SYSTEMS"; U.S. Patent No. 7,422,139, issued September 9, 2008, entitled "MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH TACTILE POSITION FEEDBACK"; U.S. Patent No. 7,464,849, issued December 16, 2008, entitled "Electro-Mechanical Surgical Instrument with Closure System and Anvil Alignment Components"; U.S. Patent No. 7,670,334, issued March 2, 2010, entitled "SURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR"; U.S. Patent No. 7,753,245, issued July 13, 2010, entitled "SURGICAL STAPLING INSTRUMENTS"; U.S. Patent No. 8,393,514, issued March 12, 2013, entitled "SELECTIVELY ORIENTABLE IMPLANTABLE FASTENER CARTRIDGE"; U.S. Patent Application No. 11 / 343,803, entitled "SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES," now U.S. Patent No. 7,845,537; U.S. Patent Application No. 12 / 031,573, filed February 14, 2008, entitled "SURGICAL CUTTING AND FASTENING INSTRUMENT HAVING RF ELECTRODES"; U.S. Patent Application No. 12 / 031,873, filed February 15, 2008, entitled "END EFFECTORS FOR A SURGICAL CUTTING AND STAPLING INSTRUMENT," now U.S. Patent No. 7,980,443; U.S. Patent Application No. 12 / 235,782, entitled "MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT," now U.S. Patent No. 8,210,411; U.S. Patent Application No. 12 / 235,972, entitled "MOTORIZED SURGICAL INSTRUMENT," now U.S. Patent No. 9,050,083; U.S. Patent Application No. 12 / 249,117, entitled "POWERED SURGICAL CUTTING AND STAPLING APPARATUS WITH MANUALLY RETRACTABLE FIRING SYSTEM," now U.S. Patent No. 8,608,045; U.S. Patent Application No. 12 / 647,100, filed December 24, 2009, entitled "MOTOR-DRIVEN SURGICAL CUTTING INSTRUMENT WITH ELECTRIC ACTUATOR DIRECTIONAL CONTROL ASSEMBLY," now U.S. Patent No. 8,220,688; U.S. Patent Application No. 12 / 893,461, filed September 29, 2012, now U.S. Patent No. 8,733,613, entitled "STAPLE CARTRIDGE"; U.S. Patent Application No. 13 / 036647, filed February 28, 2011, now U.S. Patent No. 8,561,870, entitled "SURGICAL STAPLING INSTRUMENT"; U.S. Patent Application No. 13 / 118,241, entitled "SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS," now U.S. Patent No. 9,072,535; U.S. Patent Application No. 13 / 524,049, filed June 15, 2012, entitled "ARTICULATABLE SURGICAL INSTRUMENT COMPRISING A FIRING DRIVE," now U.S. Patent No. 9,101,358; U.S. Patent Application No. 13 / 800,025, filed March 13, 2013, entitled "STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM," now U.S. Patent No. 9,345,481; U.S. Patent Application No. 13 / 800,067, filed March 13, 2013, entitled "STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM" (now U.S. Patent Application Publication No. 2014 / 0263552); U.S. Patent Application Publication No. 2007 / 0175955, filed January 31, 2006, entitled "SURGICAL CUTTING AND FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM"; and U.S. Patent Application Publication No. 2010 / 0264194, filed April 22, 2010, entitled "SURGICAL STAPLING INSTRUMENT WITH AN ARTICULATABLE END EFFECTOR," now U.S. Patent No. 8,308,040.

[0204] Although various devices are described herein in conjunction with specific embodiments, modifications and variations may be made to those embodiments. Particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, a particular feature, structure, or characteristic illustrated or described with respect to one embodiment may be combined in whole or in part with the feature, structure, or characteristic of one or more other embodiments, without limitation. Also, although materials are disclosed with respect to particular components, other materials may be used. Furthermore, multiple components may be substituted for a single component, and multiple components may be substituted for a single component, to perform a given function, according to various embodiments. The foregoing description and the following claims are intended to cover all such modifications and variations.

[0205] The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include, but is not limited to, any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces of the device, and subsequent reassembly of the device. Specifically, a reconditioning facility and / or surgical team can disassemble the device, clean and / or replace particular pieces of the device, and then reassemble the device for subsequent use. One of ordinary skill in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning / replacement, and reassembly. Use of such techniques, and the resulting reconditioned devices, are all within the scope of the present application.

[0206] The devices disclosed herein can be processed before surgery. First, new or used instruments are obtained and, if necessary, cleaned. The instruments can then be sterilized. In one sterilization technique, the instruments are placed in a closed and sealed container, such as a plastic bag or a TYVEK bag. The container and instruments can then be placed in a radiation field that can penetrate the container, such as gamma radiation, x-rays, and / or high-energy electrons. The radiation can kill bacteria on the instruments and in the container. The sterilized instruments can then be stored in the sterile container. The sealed container can keep the instruments sterile until they are opened in the medical facility. The devices can also be sterilized using any other technique known in the art, including, but not limited to, beta radiation, gamma radiation, ethylene oxide, hydrogen peroxide plasma, and / or water vapor.

[0207] While this invention has been described as having an exemplary design, the invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.

[0208] [Embodiment] (1) A surgical instrument, a surgical end effector including a firing member supported for axial advancement within the surgical end effector between a start position and an end position; an elongated shaft assembly; an articulation joint coupled to the surgical end effector and the elongate shaft assembly, the articulation joint configured to establish upper and lower pathways through the articulation joint, the upper and lower pathways being parallel to one another when the surgical end effector is in an unarticulated position, and the upper and lower pathways being concentric to one another when the surgical end effector is articulated relative to the elongate shaft assembly; a firing system configured to selectively move the firing member between the start position and the end position, the firing system comprising: an upper flexible firing assembly slidably extending through the upper passageway and in operative communication with an upper portion of the firing member; a lower flexible firing assembly slidably extending through the lower passageway and in operative communication with a lower portion of the firing member; a differential drive assembly supported proximal to the articulation joint and operatively associated with the upper firing assembly and the lower firing assembly such that, when the surgical end effector is in the non-articulated position, the differential drive assembly is configured to drive the upper and lower flexible firing assemblies in the same axial direction an equal axial distance to impart equal upper and lower axial drive motions to the firing member, and when the surgical end effector is in the articulated position, the differential drive assembly is configured to allow the upper and lower firing assemblies to move in equal but opposite axial directions and impart the upper and lower axial drive motions to the firing member. (2) The surgical instrument of embodiment 1, wherein the differential drive assembly includes an axially movable carrier assembly operatively associated with each of the upper flexible firing assembly and the lower flexible firing assembly, such that when the surgical end effector is in the non-articulated position relative to the elongate shaft assembly, the axially movable carrier assembly simultaneously applies equal amounts of axial control motion in the same axial direction to the upper flexible firing assembly and the lower flexible firing assembly to move the firing member from the starting position to the end position, and when the surgical end effector is in the articulated position relative to the elongate shaft assembly, the axially movable carrier assembly simultaneously applies another equal amount of axial control motion in the same axial direction to the upper flexible firing assembly and the lower flexible firing assembly to move the firing member from the starting position to the end position. (3) The surgical instrument of embodiment 2, wherein the upper flexible firing assembly includes an upper gear rack, the lower flexible firing assembly includes a lower gear rack, the axially movable carrier assembly includes an axially movable carrier member supported for axial advancement relative to the upper and lower gear racks, and the axially movable carrier member includes a rotatable pinion gear in meshing engagement with the upper and lower gear racks. (4) The surgical instrument of claim 3, wherein the axially movable carrier member includes a carrier rack that meshingly engages a motor-driven drive gear. (5) The surgical instrument of embodiment 3, wherein the upper flexible firing assembly further comprises an upper flexible coil member having an upper coil distal end and an upper coil proximal end, the upper distal end operably associated with the upper portion of the firing member and the upper coil proximal end coupled to the upper gear rack; and the lower flexible firing assembly further comprises a lower flexible coil member having a lower coil distal end and a lower coil proximal end, the lower coil distal end operably associated with the lower portion of the firing member and the lower coil proximal end coupled to the lower gear rack.

[0209] (6) The surgical instrument of embodiment 5, further comprising an upper cable extending through the upper flexible coil member and having an upper cable distal end and an upper cable proximal end, the upper cable distal end being coupled to the upper portion of the firing member and the upper cable proximal end being operatively associated with an articulation source; and the surgical instrument further comprising a lower cable extending through the lower flexible coil member and having a lower cable distal end and a lower cable proximal end, the lower cable distal end being coupled to the lower portion of the firing member and the lower cable proximal end being operatively associated with the articulation source. (7) The articulation joint comprises a series of movably linked annular disc members, each of the movably linked annular disc members having a first surface and a second surface, the first surface of each of the movably linked annular disc members being movably linked with the second surface of an adjacent movably linked annular disc member to facilitate relative movement in a plurality of directions between the first surface and the second surface, each of the movably linked annular disc members having an upper opening therethrough, such that each of the movably linked annular disc members in the series of movably linked annular disc members has an upper opening therethrough. 7. The surgical instrument of claim 6, wherein the upper openings of the movably linked annular disc members cooperate to form the upper passageway through the series of movably linked annular disc members for receiving the upper flexible firing assembly therethrough, and each movably linked annular disc member further has a lower opening therethrough, such that the lower openings of each movably linked annular disc member in the series of movably linked annular disc members cooperate to form the lower passageway through the series of movably linked annular disc members for receiving the lower flexible firing assembly therethrough. (8) The surgical instrument of claim 7, wherein the first surface of each of the movably associated annular disc members comprises a centrally disposed spherical feature, and the second surface of each of the movably associated annular disc members comprises a centrally disposed spherical socket, the centrally disposed spherical socket within each of the movably associated annular disc members configured to movably receive therein the centrally disposed spherical feature of an adjacent movably associated annular disc member. (9) The surgical instrument of claim 8, further comprising means for limiting pivotal travel of the centrally disposed spherical feature within the centrally disposed spherical socket of an adjacent, movably associated annular disc member to a predetermined range of pivotal travel. (10) The surgical instrument of claim 8, further comprising a resilient spacer member between each of the movably associated annular disc members.

[0210] (11) The surgical end effector includes: First Joe and 2. The surgical instrument of claim 1, comprising: a second jaw supported for movably advancement relative to the first jaw between an open position and a closed position. (12) The surgical instrument of claim 11, further comprising a plurality of actuation cables configured to impart articulation to the surgical end effector to articulate the surgical end effector relative to the elongate shaft assembly. (13) The surgical instrument of claim 12, wherein the plurality of actuation cables are configured to apply an opening motion to the surgical end effector to move the second jaw between the open position and the closed position. (14) A surgical instrument, 1. A surgical end effector, comprising: a channel configured to operably support a surgical staple cartridge therein; an anvil pivotally supported on the channel for movement between open and closed positions relative to a surgical staple cartridge supported within the channel; a tissue-cutting member supported for axial advancement within the surgical end effector between a start position and an end position, wherein the surgical instrument comprises: an elongated shaft assembly; an articulation joint coupled to the channel and the elongate shaft assembly, the articulation joint configured to establish upper and lower pathways therethrough, the upper and lower pathways being parallel to one another when the surgical end effector is in an unarticulated position, and the upper and lower pathways being concentric to one another when the surgical end effector is articulated relative to the elongate shaft assembly; and a firing system configured to selectively move the tissue-cutting member between the start position and the end position, the firing system comprising: an upper flexible coil member extending through the upper passageway and having an upper coil proximal end and an upper coil distal end, the upper coil distal end coupled to an upper portion of the tissue-cutting member; a lower flexible coil member extending through the lower passageway and having a lower coil proximal end and a lower coil distal end, the lower coil distal end coupled to a lower portion of the tissue-cutting member; a differential drive assembly supported proximal to the articulation joint and operatively associated with the upper and lower flexible coil members such that, when the surgical end effector is in the non-articulated position, the differential drive assembly is configured to drive the upper and lower flexible coil members in the same axial direction an equal axial distance to impart equal upper and lower axial drive motions to the tissue cutting member, and when the surgical end effector is in the articulated position, the differential drive assembly is configured to allow the upper and lower flexible coil members to move in equal but opposite axial directions thereafter to impart the upper and lower axial drive motions to the tissue cutting member. (15) an upper axial push rod having an upper push rod proximal end operatively associated with said differential drive assembly and an upper push rod distal end operatively associated with said upper coil proximal end; an upper push coil cable extending through the upper flexible coil member and having an upper cable distal end coupled to the upper portion of the tissue-cutting member and an upper cable proximal end coupled to the upper push rod distal end; a lower axial push rod having a lower push rod proximal end in operative communication with the differential drive assembly and a lower push rod distal end in operative communication with the lower coil proximal end; 15. The surgical instrument of claim 14, further comprising: a lower push coil cable extending through the lower flexible coil member and comprising a lower cable distal end coupled to the lower portion of the tissue cutting member and a lower cable proximal end coupled to the lower push rod distal end.

[0211] (16) The surgical instrument of embodiment 15, wherein the upper flexible coil member and a portion of the upper axial push rod are supported within the upper passage and are constrained for axial movement within an upper outer tubular member having an upper tubular member distal end supported within the surgical end effector and an upper tubular member proximal end fixed within the elongate shaft assembly, and the lower flexible coil member and a portion of the lower axial push rod are supported within the lower passage and are constrained for axial movement within a lower outer tubular member having a lower tubular member distal end supported within the surgical end effector and a lower tubular member proximal end fixed within the elongate shaft assembly. (17) The differential drive assembly includes: an upper gear rack coupled to the proximal end of the upper push rod; a lower gear rack coupled to the proximal end of the lower push rod; 17. The surgical instrument of claim 16, comprising: a carrier supported for axial movement relative to the upper and lower gear racks, the carrier comprising a rotatable pinion gear in meshing engagement with the upper and lower gear racks. (18) The surgical instrument of claim 17, wherein the axial carrier further comprises a carrier rack that meshingly engages a motor-driven drive gear. (19) The surgical instrument of embodiment 14, further comprising a plurality of actuation cables extending through the elongate shaft assembly and the articulation joint to provide actuation motion to the surgical end effector. (20) The surgical instrument of embodiment 19, wherein the plurality of actuation cables are configured to impart articulation motion to the surgical end effector for articulation relative to the elongate shaft assembly and to impart opening and closing motion to the anvil.

Claims

1. 1. A surgical instrument comprising: a surgical end effector including a firing member supported for axial advancement within the surgical end effector between a start position and an end position; an elongated shaft assembly; an articulation joint coupled to the surgical end effector and the elongate shaft assembly, the articulation joint configured to establish upper and lower pathways through the articulation joint, the upper and lower pathways being parallel to one another when the surgical end effector is in an unarticulated position, and the upper and lower pathways being concentric to one another when the surgical end effector is articulated relative to the elongate shaft assembly; a firing system configured to selectively move the firing member between the start position and the end position, the firing system comprising: an upper flexible firing assembly slidably extending through the upper passageway and in operative communication with an upper portion of the firing member; a lower flexible firing assembly slidably extending through the lower passageway and in operative communication with a lower portion of the firing member; a differential drive assembly supported proximal to the articulation joint and operatively associated with the upper and lower flexible firing assemblies, such that when the surgical end effector is in the non-articulated position, the differential drive assembly is configured to drive the upper and lower flexible firing assemblies in the same axial direction an equal axial distance to impart equal upper and lower axial drive motions to the firing member, and when the surgical end effector is in the articulated position, the differential drive assembly is configured to allow the upper and lower flexible firing assemblies to move in equal but opposite axial directions and to impart the upper and lower axial drive motions to the firing member; the upper flexible firing assembly includes an upper gear rack, and the lower flexible firing assembly includes a lower gear rack; the differential drive assembly includes an axially movable carrier member, the carrier member including a rotatable pinion gear in meshing engagement with the upper gear rack and the lower gear rack; the upper gear rack is in meshing engagement with an upper portion of the pinion gear and the lower gear rack is in meshing engagement with a lower portion of the pinion gear; when the surgical end effector is in the non-articulated position, the carrier member simultaneously applies equal amounts of axial control motion to the upper and lower flexible firing assemblies in the same axial direction, causing the upper and lower flexible firing assemblies to move in the same axial direction without rotating the pinion gear; a surgical instrument wherein, upon articulation of the surgical end effector relative to the elongate shaft assembly while the carrier member is at rest, the upper and lower flexible firing assemblies move equal lengths in opposite axial directions relative to the pinion gear, causing the pinion gear to rotate, and then the carrier member simultaneously applies equal amounts of axial control motion in the same axial direction to the upper and lower flexible firing assemblies, causing the upper and lower flexible firing assemblies to move in the same axial direction without rotating the pinion gear.

2. The surgical instrument of claim 1 , wherein the axially movable carrier member includes a carrier rack in meshing engagement with a motor-driven drive gear.

3. 2. The surgical instrument of claim 1, wherein the upper flexible firing assembly further comprises an upper flexible coil member having an upper coil distal end and an upper coil proximal end, the upper coil distal end operatively associated with the upper portion of the firing member and the upper coil proximal end coupled to the upper gear rack, and the lower flexible firing assembly further comprises a lower flexible coil member having a lower coil distal end and a lower coil proximal end, the lower coil distal end operatively associated with the lower portion of the firing member and the lower coil proximal end coupled to the lower gear rack.

4. 4. The surgical instrument of claim 3, further comprising an upper cable extending through the upper flexible coil member and comprising an upper cable distal end and an upper cable proximal end, the upper cable distal end coupled to the upper portion of the firing member and the upper cable proximal end operatively associated with an articulation source, the surgical instrument further comprising a lower cable extending through the lower flexible coil member and comprising a lower cable distal end and a lower cable proximal end, the lower cable distal end coupled to the lower portion of the firing member and the lower cable proximal end operatively associated with the articulation source.

5. The articulation joint comprises a series of movably linked annular disc members, each of the movably linked annular disc members having a first surface and a second surface, the first surface of each of the movably linked annular disc members being movably linked with the second surface of an adjacent movably linked annular disc member to facilitate relative movement in a plurality of directions between the first surface and the second surface, each of the movably linked annular disc members having an upper opening therethrough, such that each of the movably linked annular disc members in the series of movably linked annular disc members has an upper opening therethrough.

5. The surgical instrument of claim 4, wherein the upper openings of members cooperate to form the upper pathway through the series of movably linked annular disc members for receiving the upper flexible firing assembly therethrough, and each movably linked annular disc member further comprises a lower opening therethrough, such that the lower openings of each movably linked annular disc member in the series of movably linked annular disc members cooperate to form the lower pathway through the series of movably linked annular disc members for receiving the lower flexible firing assembly therethrough.

6. 6. The surgical instrument of claim 5, wherein the first surface of each of the movably associated annular disc members comprises a centrally disposed spherical feature and the second surface of each of the movably associated annular disc members comprises a centrally disposed spherical socket, the centrally disposed spherical socket in each of the movably associated annular disc members configured to movably receive therein the centrally disposed spherical feature of an adjacent movably associated annular disc member.

7. 7. The surgical instrument of claim 6, further comprising means for limiting pivotal travel of said centrally disposed spherical feature within a centrally disposed spherical socket of an adjacent said movably associated annular disc member to a predetermined range of pivotal travel.

8. The surgical instrument of claim 6, further comprising a resilient spacer member between each of said movably associated annular disc members.

9. The surgical end effector includes: The first Joe, The surgical instrument of claim 1, comprising: a second jaw supported for movably advancement relative to the first jaw between an open position and a closed position.

10. The surgical instrument of claim 9, further comprising a plurality of actuation cables configured to impart articulation to the surgical end effector to articulate the surgical end effector relative to the elongate shaft assembly.

11. The surgical instrument of claim 10, wherein the plurality of actuation cables are configured to apply an opening motion to the surgical end effector to move the second jaw between the open and closed positions.

12. 1. A surgical instrument comprising:

1. A surgical end effector, comprising: a channel configured to operably support a surgical staple cartridge therein; an anvil pivotally supported on the channel for movement between open and closed positions relative to a surgical staple cartridge supported within the channel; a tissue-cutting member supported for axial advancement within the surgical end effector between a start position and an end position, wherein the surgical instrument comprises: an elongated shaft assembly; an articulation joint coupled to the channel and the elongate shaft assembly, the articulation joint configured to establish upper and lower pathways therethrough, the upper and lower pathways being parallel to one another when the surgical end effector is in an unarticulated position, and the upper and lower pathways being concentric to one another when the surgical end effector is articulated relative to the elongate shaft assembly; and a firing system configured to selectively move the tissue-cutting member between the start position and the end position, the firing system comprising: an upper flexible coil member extending through the upper passageway and having an upper coil proximal end and an upper coil distal end, the upper coil distal end coupled to an upper portion of the tissue-cutting member; a lower flexible coil member extending through the lower passageway and having a lower coil proximal end and a lower coil distal end, the lower coil distal end coupled to a lower portion of the tissue-cutting member; a differential drive assembly supported proximal to the articulation joint and operatively associated with the upper and lower flexible coil members, such that when the surgical end effector is in the non-articulated position, the differential drive assembly is configured to drive the upper and lower flexible coil members in the same axial direction an equal axial distance to impart equal upper and lower axial drive motions to the tissue cutting member, and when the surgical end effector is in the articulated position, the differential drive assembly is configured to allow the upper and lower flexible coil members to move in equal but opposite axial directions thereafter to impart the upper and lower axial drive motions to the tissue cutting member; an upper axial push rod having an upper push rod proximal end in operative communication with the differential drive assembly and an upper push rod distal end in operative communication with the upper coil proximal end; a lower axial push rod having a lower push rod proximal end in operative communication with the differential drive assembly and a lower push rod distal end in operative communication with the lower coil proximal end; an upper gear rack coupled to the upper push rod proximal end of the upper axial push rod; a lower gear rack coupled to the lower push rod proximal end of the lower axial push rod; the differential drive assembly comprises an axially movable carrier comprising a rotatable pinion gear in meshing engagement with the upper gear rack and the lower gear rack; the upper gear rack is in meshing engagement with an upper portion of the pinion gear and the lower gear rack is in meshing engagement with a lower portion of the pinion gear; when the surgical end effector is in the non-articulated position, the carrier simultaneously applies equal amounts of axial control motion to the upper axial push rod and the lower axial push rod in the same axial direction, causing the upper axial push rod and the lower axial push rod to move in the same axial direction without rotating the pinion gear; wherein when the surgical end effector is articulated relative to the elongated shaft assembly while the carrier is at rest, the upper and lower axial push rods move equal lengths relative to the pinion gear in opposite axial directions, causing the pinion gear to rotate, and then the carrier simultaneously applies equal amounts of axial control motion in the same axial direction to the upper and lower axial push rods, causing the upper and lower axial push rods to move in the same axial direction without rotating the pinion gear.

13. An upper push coil cable extending through the upper flexible coil member and having an upper cable distal end connected to the upper portion of the tissue-cutting member and an upper cable proximal end connected to the upper push rod distal end; 13. The surgical instrument of claim 12, further comprising a lower push coil cable extending through the lower flexible coil member and comprising a lower cable distal end coupled to the lower portion of the tissue-cutting member and a lower cable proximal end coupled to the lower push rod distal end.

14. 14. The surgical instrument of claim 13, wherein the upper flexible coil member and a portion of the upper axial push rod are supported within the upper passage and constrained for axial movement within an upper outer tubular member having an upper tubular member distal end supported within the surgical end effector and an upper tubular member proximal end fixed within the elongate shaft assembly, and the lower flexible coil member and a portion of the lower axial push rod are supported within the lower passage and constrained for axial movement within a lower outer tubular member having a lower tubular member distal end supported within the surgical end effector and a lower tubular member proximal end fixed within the elongate shaft assembly.

15. The surgical instrument of claim 12, wherein the carrier further comprises a carrier rack that meshes with a motor-driven drive gear.

16. The surgical instrument of claim 12, further comprising a plurality of actuation cables extending through the elongate shaft assembly and the articulation joint to provide actuation motion to the surgical end effector.

17. The surgical instrument of claim 16, wherein the plurality of actuation cables are configured to impart articulation motion to the surgical end effector for articulation relative to the elongate shaft assembly and to impart opening and closing motion to the anvil.

Images