Powered stapling device with manual override mechanism

Abstract

A surgical device (10) includes a powered handle assembly (12) coupled to a tool assembly (16) by an elongate body (14). The power handle assembly (12) includes a motor assembly (46) coupled to a rack (48) by a gear assembly (51). The motor assembly (46) may be actuated to advance or retract the rack (48) to actuate the tool assembly (16). The handle assembly (12) includes a housing (18) defining an opening (84) sized to receive a retraction tool (90) configured to engage the gear assembly (51) and manually override the motor assembly (46) to facilitate manual retraction of the rack (48).

Description

Technical Field

[0001] The present disclosure relates to powered surgical devices, and more particularly to powered surgical devices having a manual override mechanism. Background Art

[0002] Various types of surgical devices for endoscopically treating tissue are known in the art and are commonly used, for example, to close tissue or organs in transection, resection and anastomosis procedures, to occlude organs in thoracic and abdominal surgery, and to electrosurgically fuse or seal tissue.

[0003] An example of such a surgical device is a surgical stapling device. Typically, the surgical stapling device includes a tool assembly having an anvil assembly and a cartridge assembly, and a drive assembly. The drive assembly includes a flexible drive beam and a clamp member supported on the distal end of the drive beam. The drive assembly is movable to advance the clamp member through the tool assembly to approach the cartridge assembly and the anvil assembly, and to advance the actuating slide through the cartridge assembly to eject the staples from the cartridge assembly.

[0004] Surgical stapling devices can be manually actuated devices, in which the clinician squeezes a trigger to actuate the stapling device or powered stapling devices, in which the clinician actuates a motor within the stapling device to actuate the stapling device. Although powered stapling devices require less force to operate, difficulties may arise when the device loses power or a component of the device fails or becomes damaged. In such a case, the device remains clamped around the tissue, thereby preventing the device from being removed from the patient.

[0005] There continues to be a need in the art for a powered suturing device that includes a drive assembly that can be manually retracted to facilitate removal from a patient upon loss of power or when the device becomes inoperable. Summary of the invention

[0006] A surgical device includes a power handle assembly coupled to a tool assembly via an elongated body. The power handle assembly includes a motor assembly coupled to a rack via a gear assembly. The motor assembly can be actuated to advance or retract the rack, thereby actuating the tool assembly. The handle assembly includes a housing defining an opening that receives a retraction tool configured to engage the gear assembly and manually override the motor assembly to facilitate manual retraction of the rack.

[0007] Aspects of the present disclosure relate to a power handle assembly for a surgical device, the power handle assembly comprising a housing, a motor assembly, a rack, a gear shaft, a spur gear and a bevel gear. The housing defines a cavity and an opening communicating with the cavity. The motor assembly is supported in the cavity of the housing and comprises a motor shaft and an output gear fixed to the motor shaft. The rack is received in the cavity of the housing and is supported to move longitudinally between a retracted position and an advanced position. The gear shaft is supported in the cavity of the housing. The spur gear is rotatably supported on the gear shaft and can move linearly along the gear shaft between a first position and a second position. The spur gear comprises a gear member and a cylindrical shaft portion. The gear member engages with the rack so that rotation of the spur gear causes longitudinal movement of the rack between the retracted position and the advanced position. The bevel gear is rotatably supported around the gear shaft and engages with the output gear of the motor assembly. The spur gear engages with the bevel gear when the spur gear is in the first position and disengages with the bevel gear when the spur gear is in the second position, such that when the spur gear is in the first position, rotation of the bevel gear causes rotation of the spur gear to move the rack longitudinally between the retracted position and the advanced position.

[0008] In aspects of the present disclosure, the handle assembly includes a biasing member positioned to urge the spur gear toward the first position.

[0009] In some aspects of the present disclosure, the power handle assembly includes a retraction tool sized to be received through the opening in the housing to move the spur gear from the first position to the second position.

[0010] In certain aspects of the present disclosure, the cylindrical shaft portion of the spur gear includes a first end spaced apart from the gear member, the first end being configured to be coupled to a retraction tool such that when the spur gear is in the second position, rotation of the retraction tool causes the spur gear to rotate independently of the bevel gear.

[0011] In aspects of the present disclosure, a retraction tool includes a shaft and a handle coupled to the shaft, and the shaft of the retraction tool has a first end spaced apart from the handle and configured to couple to a first end of a cylindrical shaft portion of a spur gear.

[0012] In some aspects of the present disclosure, a first end of the shaft of the retraction tool and a first end of the cylindrical shaft portion of the spur gear include castellations that engage one another such that rotation of the retraction tool causes corresponding rotation of the spur gear.

[0013] In certain aspects of the present disclosure, the bevel gear is supported around the cylindrical shaft portion of the spur gear.

[0014] In aspects of the present disclosure, a bearing is supported on the bevel gear and positioned around the cylindrical shaft portion of the spur gear.

[0015] In some aspects of the present disclosure, the spur gear supports a protrusion, the bevel gear defines a cutout, and when the spur gear is in the first position, the protrusion is received within the cutout to couple the spur gear to the bevel gear.

[0016] Other aspects of the present disclosure relate to a surgical device comprising a power handle assembly, an elongated body and a tool assembly. The power handle assembly comprises a housing, a motor assembly, a rack, a gear shaft, a spur gear and a bevel gear. The housing defines a cavity and an opening communicating with the cavity. The motor assembly is supported in the cavity of the housing and comprises a motor shaft and an output gear fixed to the motor shaft. The rack is received in the cavity of the housing and is supported to move longitudinally between a retracted position and an advanced position. The gear shaft is supported in the cavity of the housing. The spur gear is rotatably supported on the gear shaft and can move linearly along the gear shaft between a first position and a second position. The spur gear comprises a gear member and a cylindrical shaft portion. The gear member engages with the rack so that rotation of the spur gear causes longitudinal movement of the rack between the retracted position and the advanced position. The bevel gear is rotatably supported around the gear shaft and engages with the output gear of the motor assembly. The spur gear engages with the bevel gear when the spur gear is in the first position and disengages with the bevel gear when the spur gear is in the second position, so that when the spur gear is in the first position, rotation of the bevel gear causes rotation of the spur gear to move the rack longitudinally between the retracted position and the advanced position. The elongated body includes a firing rod that is coupled to the rack and has a proximal portion and a distal portion. The proximal portion of the elongated body is coupled to the power handle assembly. The tool assembly is supported on the distal portion of the elongated body.

[0017] In aspects of the present disclosure, a tool assembly includes an anvil and a cartridge assembly.

[0018] Other features of the present disclosure will be understood from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various aspects of the disclosed surgical device are described below with reference to the accompanying drawings, in which:

[0020] Figure 1 is a side perspective view of a surgical device according to aspects of the present disclosure, wherein a tool assembly of the surgical device is in a non-articulated, unclamped position;

[0021] Figure 2 is from Figure 1 A perspective view of a proximal end of a handle assembly of a surgical device shown in FIG. 1 , wherein a housing of the handle assembly is shown in phantom, showing internal components of the handle assembly, including a motor assembly, a rack, a spur gear, and a bevel gear;

[0022] Figure 3 yes Figure 2An exploded perspective view of the internal components of the handle assembly associated with the retraction tool shown in FIG.

[0023] Figure 4 yes Figure 2 A side perspective view of the spur gear and bevel gear of the handle assembly shown in , with the components separated;

[0024] Figure 5 yes Figure 3 A side perspective view of the spur gear and retraction tool of the handle assembly shown in , with the components separated;

[0025] Figure 6 It is along Figure 2 A cross-sectional view taken along section line 6-6;

[0026] Figure 7 yes Figure 1 A side perspective view of a surgical device shown in , wherein the surgical device is in a clamped position;

[0027] Figure 8 yes Figure 7 A side perspective view of the surgical device shown in FIG. 1 in an unclamped position with the retraction tool engaged with the handle assembly; and

[0028] Fig. 9 It is along Figure 8 A cross-sectional view taken along section line 9-9. DETAILED DESCRIPTION

[0029] The disclosed surgical device will now be described in detail with reference to the drawings, in which the same reference numerals refer to the same or corresponding elements in each of the several views. However, it should be understood that the various aspects of the present disclosure are merely illustrative of the present disclosure and may be embodied in various forms. Well-known functions or configurations are not described in detail to avoid obscuring the present disclosure with unnecessary detail. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as the basis of the claims and as a representative basis for teaching those skilled in the art to employ the present disclosure differently in almost any suitable specific structure. In addition, directional terms such as front, rear, upper, lower, top, bottom, and similar terms are used to aid in understanding the present specification and are not intended to limit the present disclosure.

[0030] In this specification, the term "proximal" is generally used to refer to that portion of the device that is closer to the clinician during use of the device in its customary manner, and the term "distal" is generally used to refer to that portion of the device that is farther from the clinician during use of the device in its customary manner. In addition, the term "endoscopic" is generally used to refer to endoscopy, laparoscopy, arthroscopy, and / or any other procedure performed through a small diameter incision or cannula. In addition, the term "clinician" is generally used to refer to medical staff including doctors, nurses, surgeons, and support staff.

[0031] The present disclosure relates to a surgical device including a power handle assembly coupled to a tool assembly via an elongated body. The power handle assembly includes a motor assembly coupled to a rack via a gear assembly. The motor assembly can be actuated to advance or retract the rack, thereby actuating the tool assembly. The handle assembly includes a housing defining an opening that receives a retraction tool configured to engage the gear assembly and manually override the motor assembly to facilitate manual retraction of the rack.

[0032] Figure 1 A surgical device, generally shown as a suturing device 10, is shown. The surgical device 10 includes a handle assembly 12, an elongated body 14, and a tool assembly 16. The handle assembly 12 includes a housing 18 forming a fixed handle portion 18a, an articulating lever 19, and an actuation button 20. The housing 18 of the handle assembly 12 is formed of half sections that are coupled together, such as by welding or screwing, to define a cavity 38 ( Figure 2 ), the cavity receives the internal components of the handle assembly 12, which internal components will be described in further detail below.

[0033] The elongated body 14 defines a longitudinal axis "X" and includes a proximal portion 24 coupled to the handle assembly 12 and a distal portion 26 supporting a tool assembly 16. The tool assembly 16 is secured to the distal portion 26 of the elongated body 14 by a pivot member 28 that defines an axis "Y" transverse to the longitudinal axis "X". An articulated lever 19 is operatively coupled to the tool assembly 16 via an articulated link (not shown) such that manipulation of the articulated lever 19 causes articulation of the tool assembly 16 about the axis "Y" between a non-articulated position in which the tool assembly 16 defines a longitudinal axis aligned with the longitudinal axis "X" and a non-articulated position in which the longitudinal axis of the tool assembly 16 and the longitudinal axis "X" of the elongated body 14 define an acute angle.

[0034] The proximal portion 24 of the elongated body 14 is supported within a knob 30 that is rotatably coupled to the distal portion of the handle assembly 12. The knob 30 can be manually rotated about the longitudinal axis "X" to rotate the elongated body 14 and the tool assembly 16 about the longitudinal axis "X". The actuation button 20 controls the operation of different functions of the suturing device 10, including clamping and firing of the suturing device 10.

[0035] Figure 2 and Figure 3 The handle assembly 12 ( Figure 1 ) includes a motor assembly 46, a rack 48, a firing rod 50, and a gear assembly 51. The rack 48 is coupled to the firing rod 50 so that longitudinal movement of the rack 48 causes longitudinal movement of the firing rod 50. The gear assembly 51 includes a bevel gear 52, a spur gear 54, and a gear shaft 56. The motor assembly 46 includes a motor shaft 58 that supports an output gear 60 that engages with the bevel gear 52 of the gear assembly 51. The output gear 60 is securely fixed to the motor shaft 58 so that rotation of the motor shaft 58 causes corresponding rotation of the output gear 60. When the actuation button 20 ( Figure 1 ) to actuate the motor assembly 46, the rotation of the motor shaft 58 rotates the drive gear 56 to rotate the bevel gear 52. In various aspects of the present disclosure, the motor assembly 46 is positioned between the fixed handle portion 18a ( Figure 3 ) defines a cavity 38 of the housing 18 ( Figure 2 ) part.

[0036] The bevel gear 52 and the spur gear 54 are rotatably supported on the gear shaft 56 on the handle assembly 12 ( Figure 1 ) in the housing 18 of the handle assembly 12. The gear shaft 56 is supported in the cavity 38 ( Figure 2 ) and defines an axis substantially perpendicular to the longitudinal axis "X" defined by the elongated body 14. One end of the gear shaft 56 includes a head portion 56a having a diameter greater than the remaining portion of the gear shaft 56. In various aspects of the present disclosure, the gear shaft 56 is rotatably supported on the housing 18 of the handle assembly 12 or on a gear box (not shown) supported within the housing 18. In various aspects of the present disclosure, the head portion 56a is supported in a recess 71 ( Figure 6 ) to support the gear shaft 56 in the cavity 38 ( Figure 2 )Inside.

[0037] Figure 4 and Figure 5 The spur gear 54 is shown, which includes a central hub portion 64 and a gear member 66 formed around the central hub portion 64. The central hub portion 64 of the spur gear 54 defines a through hole 68 ( Figure 5), the through hole receives the gear shaft 56 so that the spur gear 54 is rotatably supported on the gear shaft 56. The spur gear 54 can move along the gear shaft 56 between a first position and a second position. Figure 6 ), the spur gear 54 engages with the bevel gear 52, and in the second position ( Fig. 9 ), the spur gear 54 is disengaged from the bevel gear 52. In various aspects of the present disclosure, the biasing member 70 is positioned between the head portion 56a of the gear shaft 56 and the spur gear 54 to push the spur gear 54 to the first position engaged with the bevel gear 52.

[0038] The central hub portion 64 of the spur gear 54 extends outwardly from the gear member 66 and defines a cylindrical shaft portion 72. The cylindrical shaft portion 72 of the spur gear 54 extends through a central opening 74 ( Figure 4 ) and includes a projection 76 positioned adjacent to the gear member 66. When the spur gear 54 is in the first position, the projection 76 of the spur gear 54 is received in a notch 78 ( Figure 4 ) to secure the spur gear 54 to the bevel gear 52. In various aspects of the present disclosure, the spur gear includes four protrusions and the bevel gear includes four cutouts. When the protrusion 76 of the spur gear 54 is received in the cutout 78 of the bevel gear 52, rotation of the bevel gear 52 causes corresponding rotation of the spur gear 54. In various aspects of the present disclosure, the bevel gear 52 defines a receiving bearing 82 ( Figure 3 ) of the cylindrical recess 80. The bearing 82 defines a central through hole 82a that receives the cylindrical shaft portion 72 of the spur gear 54 and allows the bevel gear 52 to be rotatably supported on the spur gear 54.

[0039] The cylindrical shaft portion 72 of the spur gear 54 extends outwardly from the gear member 66 of the spur gear 54 into or adjacent an opening 84 ( Figure 1 ). An opening in the housing 18 of the handle assembly 12 is aligned with the cylindrical shaft portion 72 of the spur gear 54. The end of the cylindrical shaft portion 72 opposite the gear member 66 defines a first castellation 86 positioned within the opening 84 of the housing 18 of the handle assembly 12. The first castellation 86 on the cylindrical shaft portion 72 of the spur gear 54 is configured to engage a retraction tool 90 as described below, such that rotation of the retraction tool 90 causes rotation of the spur gear 54.

[0040] Figure 5 A retraction tool 90 is shown, which includes a shaft 92 and a handle 94. The shaft 92 is substantially linear and extends through an opening 84 ( Figure 1) is received to engage with the spur gear 54. More specifically, the shaft 92 of the retraction tool 90 includes an end opposite the handle 94 of the retraction tool 90 that defines a second castellation 96. The castellation 96 of the retraction tool 90 is configured to engage or mesh with the castellation 86 of the spur gear 54 to rotatably secure the retraction tool 90 to the spur gear 54 such that rotation of the retraction tool 90 causes corresponding rotation of the spur gear 54. It is contemplated that the spur gear 54 and the retraction tool 90 may have a variety of different interlocking or engaging configurations that rotatably secure the retraction tool 90 to the spur gear 54 such that rotation of the retraction tool 90 causes corresponding rotation of the spur gear 54.

[0041] In various aspects of the present disclosure, tool assembly 16 is in the form of a stapling device and includes an anvil 100 and a cartridge assembly 102. Cartridge assembly 100 has a cartridge 104 that supports a plurality of staples (not shown) and is capable of being opened relative to anvil 100 in an open position ( Figure 1 ) and clamping position ( Figure 7 ) to clamp tissue "T" between anvil 100 and cartridge assembly 102. It is contemplated that tool assembly 16 may have a variety of different forms to perform a variety of different surgical procedures. For example, tool assembly 16 may include a container sealing device or a clip applying device.

[0042] Figure 6 and Figure 7 The handle assembly 12 is shown with the spur gear 54 in a first position. When the power handle assembly 12 is operated in its intended manner, the spur gear 54 is urged by the biasing member 70 into engagement with the bevel gear 52. When the spur gear 54 is engaged with the bevel gear 52, the protrusion 76 ( Figure 4 ) is received in the cutout 78 of the bevel gear 52 so that rotation of the bevel gear 52 causes corresponding rotation of the spur gear 54. As described above, the bevel gear 52 is connected to the motor assembly 46 ( Figure 3 ), and the spur gear 54 engages with the rack 48. Therefore, when the motor assembly 46 is activated, the output gear 60 of the motor assembly 46 rotates the bevel gear 52 to rotate the spur gear 54. When the spur gear 54 rotates, the rack 48 moves linearly within the cavity 38 of the housing 18 of the handle assembly 12 to advance the firing rod 50. The firing rod 50 is coupled to the tool assembly 16 to actuate the tool assembly when the firing rod 50 is advanced.

[0043] Figure 8 and Fig. 9 The suturing device 10 is shown with the spur gear 54 moved to the second position. When a power suturing device fails and the motor assembly 46 loses power or the device fails, the retraction tool 90 can be used to retract the firing rod 50 ( Figure 2) to move the tool assembly 16 from the clamped position to the unclamped position. To manually retract the firing rod 50, the shaft 92 of the retraction tool 90 is inserted into the opening 84 in the housing 18 of the handle assembly 12 and inserted into engagement with the cylindrical shaft portion 72 of the spur gear 54. When the end of the shaft 92 of the retraction tool 90 engages with the end of the cylindrical shaft portion 72 of the spur gear 54, the castellations 96 of the retraction tool 90 engage or mesh with the castellations 86 of the spur gear 54 to rotatably secure the retraction tool 90 to the spur gear 54. When the shaft 92 of the retraction tool 90 is in Fig. 9 When inserted through the opening 84 in the direction of arrow "A" in FIG. Fig. 9 In the second position, the protrusion 76 ( Figure 4 ) moves from the cutout 78 of the bevel gear 52 to disengage the spur gear 54 from the bevel gear 52. When the spur gear 54 is disengaged from the bevel gear 52, the retraction tool 90 can be Figure 8 54. As the spur gear 54 moves from the first position to the second position, the spur gear 54 remains engaged with the rack 48, so that the rotation of the spur gear 54 causes the retraction of the rack 50 to retract the firing rod 50. As the firing rod 50 retracts, the tool assembly 16 moves from the clamped position to the unclamped position.

[0044] Those skilled in the art will appreciate that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary aspects of the present disclosure. It is contemplated that the elements and features illustrated or described in conjunction with an exemplary aspect of the present disclosure may be combined with the elements and features of another aspect without departing from the scope of the present disclosure. Similarly, those skilled in the art will understand the additional features and advantages of the present disclosure based on the above-mentioned aspects of the present disclosure. Therefore, the present disclosure is not limited by what has been specifically illustrated and described, unless indicated by the appended claims.

Claims

1. A power handle assembly for a surgical device, comprising: a housing defining a cavity and an opening in communication with the cavity; a motor assembly supported within the cavity of the housing and including a motor shaft and an output gear secured to the motor shaft; a rack received within the cavity of the housing, the rack supported for longitudinal movement between a retracted position and an advanced position; a gear shaft supported in the cavity of the housing; a spur gear rotatably supported on the gear shaft and linearly movable along the gear shaft between a first position and a second position, the spur gear comprising a gear member and a cylindrical shaft portion, the gear member engaging the rack such that rotation of the spur gear causes longitudinal movement of the rack between the retracted position and the advanced position; and A bevel gear rotatably supported about the gear shaft and engaged with the output gear of the motor assembly, the spur gear engaged with the bevel gear when the spur gear is in the first position and disengaged from the bevel gear when the spur gear is in the second position, wherein when the spur gear is in the first position, rotation of the bevel gear causes rotation of the spur gear to move the rack longitudinally between the retracted position and the advanced position.

2. The power handle assembly of claim 1, further comprising a biasing member positioned to urge the spur gear toward the first position.

3. The power handle assembly of claim 2, further comprising a retraction tool sized to be received through the opening in the housing to move the spur gear from the first position to the second position.

4. The power handle assembly according to claim 3, wherein: The cylindrical shaft portion of the spur gear includes a first end spaced apart from the gear member, the first end being configured to be coupled to the retraction tool such that rotation of the retraction tool causes rotation of the spur gear independent of the bevel gear when the spur gear is in the second position.

5. The power handle assembly according to claim 4, wherein: The retraction tool includes a shaft and a handle coupled to the shaft, the shaft of the retraction tool having a first end spaced apart from the handle, the first end configured to couple to the first end of the cylindrical shaft portion of the spur gear.

6. The power handle assembly according to claim 5, wherein: The first end of the shaft of the retraction tool and the first end of the cylindrical shaft portion of the spur gear include castellations that engage one another such that rotation of the retraction tool causes corresponding rotation of the spur gear.

7. The power handle assembly according to claim 1, wherein: The bevel gear is supported around the cylindrical shaft portion of the spur gear.

8. The power handle assembly of claim 7, further comprising a bearing supported on the bevel gear and positioned about the cylindrical shaft portion of the spur gear.

9. The power handle assembly according to claim 1, wherein: The spur gear supports a protrusion, and the bevel gear defines a cutout, the protrusion being received within the cutout to couple the spur gear to the bevel gear when the spur gear is in the first position.

10. A surgical device comprising: A power handle assembly, the power handle assembly comprising: a housing defining a cavity and an opening in communication with the cavity; a motor assembly supported within the cavity of the housing and including a motor shaft and an output gear secured to the motor shaft; a rack received within the cavity of the housing, the rack supported for longitudinal movement between a retracted position and an advanced position; a gear shaft supported in the cavity of the housing; a spur gear rotatably supported on the gear shaft and linearly movable along the gear shaft between a first position and a second position, the spur gear comprising a gear member and a cylindrical shaft portion, the gear member engaging the rack such that rotation of the spur gear causes longitudinal movement of the rack between the retracted position and the advanced position; and a bevel gear rotatably supported about the gear shaft and engaged with the output gear of the motor assembly, the spur gear engaged with the bevel gear when the spur gear is in the first position and disengaged from the bevel gear when the spur gear is in the second position, wherein rotation of the bevel gear when the spur gear is in the first position causes rotation of the spur gear to move the rack longitudinally between the retracted position and the advanced position; an elongated body having a proximal portion and a distal portion, the proximal portion of the elongated body being coupled to the power handle assembly, the elongated body including a firing rod coupled to the rack; and A tool assembly is supported on the distal portion of the elongated body.

11. The surgical device according to claim 10, wherein: The tool assembly includes an anvil and a cartridge assembly.

12. The surgical device of claim 11, further comprising a biasing member positioned to urge the spur gear toward the first position.

13. The surgical device of claim 12, further comprising a retraction tool sized to be received through the opening in the housing to move the spur gear from the first position to the second position.

14. The surgical device according to claim 13, wherein: The cylindrical shaft portion of the spur gear includes a first end spaced apart from the gear member, the first end being configured to be coupled to the retraction tool such that rotation of the retraction tool causes rotation of the spur gear independent of the bevel gear when the spur gear is in the second position.

15. The surgical device of claim 14, wherein: The retraction tool includes a shaft and a handle coupled to the shaft, the shaft of the retraction tool having a first end spaced apart from the handle, the first end configured to couple to the first end of the cylindrical shaft portion of the spur gear.

16. The surgical device of claim 15, wherein: The first end of the shaft of the retraction tool and the first end of the cylindrical shaft portion of the spur gear include castellations that engage one another such that rotation of the retraction tool causes corresponding rotation of the spur gear.

17. The surgical device of claim 11, wherein: The bevel gear is supported around the cylindrical shaft portion of the spur gear.

18. The surgical device of claim 17, further comprising a bearing supported on the bevel gear and positioned about the cylindrical shaft portion of the spur gear.

19. The surgical device of claim 11, wherein: The spur gear supports a protrusion, and the bevel gear defines a cutout, the protrusion being received within the cutout to couple the spur gear to the bevel gear when the spur gear is in the first position.

20. The surgical device of claim 19, wherein: The spur gear includes four protrusions, and the bevel gear defines four cutouts.

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