Method of securing a surgical instrument shaft to an instrument housing

Abstract

A surgical instrument having: a housing; an outer shaft extending from the housing along a longitudinal axis; an inner shaft extending within the outer shaft along the longitudinal axis; a rotor knob positioned around the outer shaft; and a tube stopper coupling the rotor knob to the outer shaft for collective rotation about the longitudinal axis and secured within the housing to prevent movement along the longitudinal axis. The tube stopper has a pair of bearing surfaces extending into a pair of longitudinal tracks of the outer shaft, and the rotor knob includes a pair of guide rails extending into the pair of tracks of the outer shaft and blocking the tube stopper from leaving the tracks. The tube stopper is captured between a pair of ribs in the housing to hold the tube stopper in place while allowing the rotor knob to rotate the outer shaft.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional No. 62 / 767014, filed on November 14, 2018. Background Art 1. Technical Field

[0004] The present invention relates to surgical instruments and, more particularly, to a method for securing an elongated shaft to a housing for rotational movement.

[0005] 2. Description of related technologies

[0006] Surgical instruments such as vessel sealers include a handle from which a shaft extends and supports a surgical tool such as a pair of jaws that can be manipulated by a surgeon to perform a procedure. Positioning the tool on a patient may require rotating the entire surgical instrument to rotate the tool at the end of the shaft. For example, in order to position the jaws of a vessel sealer around a blood vessel, the surgeon may need to rotate the jaws so that the jaws can surround the blood vessel before closing the jaws. Therefore, there is a need in the art for a method that allows a user to more easily rotate the instrument at the end of the shaft during surgery so that the tool can be more accurately aligned during surgery. Summary of the invention

[0007] The present invention fixes the shaft of a surgical instrument to the housing of the instrument while allowing the shaft to rotate by a rotor knob. More specifically, the present invention includes a surgical instrument having: a housing; an outer shaft extending from the housing along a longitudinal axis; an inner shaft extending within the outer shaft along the longitudinal axis; a rotor knob positioned around the outer shaft; and a tube stopper coupling the rotor knob to the outer shaft for collective rotation around the longitudinal axis and fixed within the housing to prevent movement along the longitudinal axis. A pair of tracks extends longitudinally in the outer shaft. The tube stopper has a pair of bearing surfaces extending into the pair of tracks, respectively. The rotor knob includes a pair of guide rails extending into the pair of tracks of the outer shaft, respectively. Each of the pair of tracks includes a first portion extending longitudinally in the outer shaft and a second portion extending circumferentially from an end of the first portion. Each of the pair of bearing surfaces of the tube stopper is positioned in the second portion of each of the pair of tracks, respectively. The guide rail of the rotor knob extends to the end of the portion of each of the tracks to prevent the tube stop from rotating out of the second portion of each of the tracks. The tube stop is captured between a pair of ribs in the housing. The tube stop includes a second pair of bearing surfaces that engage the outer shaft. The tube stop includes a third pair of bearing surfaces that engage the ribs of the rotor knob.

[0008] The present invention also includes a method of coupling elements of a surgical instrument for common rotation. The method includes the steps of providing a housing; an outer shaft extending from the housing along a longitudinal axis; an inner shaft extending within the outer shaft along the longitudinal axis; positioning a rotor knob around the outer shaft adjacent to the tube stop and in interlocking engagement with the outer shaft; and securing the tube stop within the housing to prevent movement of the tube stop along the longitudinal axis. The rotor knob includes a pair of guide rails extending within a pair of tracks of the outer shaft, respectively. A pair of bearing surfaces of the tube stop extend into the pair of tracks, respectively, and are secured in place by the pair of guide rails of the rotor knob. Each of the pair of tracks includes a first portion that receives one of the pair of tracks of the rotor knob and a second portion that extends circumferentially from the first portion and receives one of the bearing surfaces of the tube stop. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will be more fully understood and appreciated by reading the following detailed description in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is an exploded isometric view of a surgical instrument according to the present invention;

[0011] Figure 2 is an end view of a tube stopper according to the present invention;

[0012] Figure 3 is a perspective view of the positioning of tube stops over the inner and outer shafts of a surgical instrument according to the present invention;

[0013] Figure 4 is a perspective view of the positioning of tube stops over the inner and outer shafts of a surgical instrument according to the present invention;

[0014] Figure 5 is a perspective view of the positioning of tube stops over the inner and outer shafts of a surgical instrument according to the present invention;

[0015] Figure 6 is a perspective view of the positioning of the rotor knobs over the inner and outer shafts of the surgical instrument according to the present invention;

[0016] Fig. 7A is a side view of a rotor knob according to the present invention;

[0017] Figure 7B is a perspective view of a rotor knob according to the present invention;

[0018] Figure 8 is a side view of the inner surface of a housing according to the present invention; and

[0019] Fig. 9 is a side view of the interior surface of the housing with the rotor knob and tube stop in place according to the present invention. DETAILED DESCRIPTION

[0020] Referring to the drawings, wherein like reference numerals refer to like parts throughout, Figure 1 1 is a view of a surgical instrument 10 having a housing 12. As is known in the art, the housing 12 is shaped to allow a surgeon to grasp the proximal end of the surgical instrument 10 for use during a surgical procedure. The surgical instrument 10 also includes an outer shaft 14 extending distally from a portion of the housing 12 along a longitudinal axis XX and an inner shaft 16 extending within the outer shaft 14. A rotor knob 18 is interconnected with the outer shaft 14 to allow a user to rotate the outer shaft 14. A tube stop 20 engages both the outer shaft 14 and the rotor knob 18 to interlock the outer shaft 14 and the rotor knob 18 for common rotation.

[0021] refer to Figure 2 , the tube stopper 20 includes a body 22 formed as a disk and including an opening 24 therethrough. The opening 24 is defined by a first set of bearing surfaces 26, a second set of bearing surfaces 28, and a third set of bearing surfaces 30. The first set of bearing surfaces 26 engage an outer surface 32 of the outer shaft 14. The second set of bearing surfaces 28 engage an outer surface 34 of the inner shaft 16 via a pair of corresponding tracks 36 formed through the outer shaft 14. Fig. 7A and Figure 7B As seen in FIG. 8 , the third set of surfaces 30 engage a pair of corresponding rails 40 extending longitudinally from the rotor knob 18 .

[0022] refer to Figure 3 , the tube stop 20 is positioned around the outer shaft 14, and the inner shaft 16 is positioned within the outer shaft 14. The second set of bearing surfaces 28 are aligned with tracks 36 formed in the outer surface 38 of the outer shaft 14. Figure 4 As seen in FIG. 1 , the track 36 includes a first portion 42 that extends longitudinally from the end of the outer shaft 14 to an inner end 46 parallel to the axis XX. A second portion 44 extends circumferentially around a portion of the outer shaft 14 at a suitable angle from the end 46 of the first portion 42 toward the first portion 42 and thus the axis XX. Figure 5 As seen in FIG, the second portion 44 is in communication with the first portion 42 such that the second set of support surfaces 28 of the tube stop 20 may pass along the first portion 42 and then rotate into the second portion 44, thereby capturing the second set of support surfaces 28 within the second portion 44 of the track 36 and preventing longitudinal movement of the support surfaces 28.

[0023] refer to Figure 6, the rotor knob 18 passes through the inner shaft 16 so that the guide rail 40 engages the third set of bearing surfaces 30. The guide rail 40 is shaped to slide along the track 36 of the outer shaft 14 to the end 46 of the first portion 42, thereby preventing the tube stop 20 from rotating out of the second portion 44 of the track 36. The interconnection between the guide rail 40 of the rotor knob 18 and the track 36 interlocks the rotor knob 18 with the outer shaft 14 for common rotation therewith. The third set of bearing surfaces 30 securely captures the guide rail 40 to hold the guide rail within the track 36.

[0024] refer to Figure 8 , the housing 12 includes a pair of spaced apart ribs 50 that are positioned to capture and retain the tube stop 20 within the housing 12. Thus, as Fig. 9 As seen in the figure, the ribs 50 prevent the tube stop 20 from moving proximally or distally along the axis XX, thereby fixing the outer shaft 14 relative to the housing 12. The inner shaft 16 extends proximally through the housing 12 and is able to move longitudinally along the axis XX, while the shaft 14 is fixed to prevent movement. Rotation of the rotor knob 18 will cause the outer shaft 14 to rotate, but will not cause the inner shaft 16 to rotate. As is known in the art, the inner shaft 16 can be coupled to a mechanism in the housing 12 that can move the inner shaft 16 relative to the outer shaft 14 to drive a surgical tool, such as a pair of opposing jaws, etc., positioned at the distal end of the inner shaft 16.

Claims

1. A surgical instrument, comprising: case; an outer shaft extending from the housing along a longitudinal axis; an inner shaft extending within the outer shaft along the longitudinal axis; a rotor knob positioned about the outer shaft; as well as a tube stop coupling the rotor knob to the outer shaft for collective rotation about the longitudinal axis and secured within the housing to prevent movement along the longitudinal axis, wherein the outer shaft includes a pair of tracks formed therein extending longitudinally, the tracks being configured to guide the tube stop to position the tube stop on the inner shaft, and The tube stop includes a body and an opening therethrough, the opening being defined by a first set of bearing surfaces engaging an outer surface of the outer shaft, a second set of bearing surfaces engaging an outer surface of the inner shaft via a pair of tracks of the outer shaft, and a third set of bearing surfaces engaging a pair of rails extending longitudinally from the rotor knob.

2. The surgical instrument of claim 1, wherein the pair of guide rails of the rotor knob extend into the pair of tracks of the outer shaft, respectively.

3. The surgical instrument of claim 2, wherein each of the pair of rails comprises a first portion extending longitudinally in the outer shaft and a second portion extending circumferentially from an end of the first portion.

4. The surgical instrument of claim 3, wherein each of the second set of bearing surfaces of the tube stop is positioned in the second portion of each of the pair of tracks, respectively.

5. The surgical instrument of claim 4, wherein the pair of guide rails of the rotor knob extend to the end of the first portion of each of the pair of tracks to prevent the tube stop from rotating out of the second portion of each of the pair of tracks.

6. The surgical instrument of claim 5, wherein the tube stop is captured between a pair of ribs in the housing.

7. A method of coupling elements of a surgical instrument according to claim 1 for common rotation, the method comprising the steps of: providing a housing, an outer shaft extending from the housing along a longitudinal axis, and an inner shaft extending within the outer shaft along the longitudinal axis; positioning a tube stop about the outer shaft; positioning a rotor knob about the outer shaft adjacent the tube stop and in interlocking engagement with the outer shaft; as well as The tube stop is secured within the housing to prevent movement of the tube stop along the longitudinal axis.

8. The method of claim 7, wherein the rotor knob comprises a pair of rails extending within a pair of tracks of the outer shaft, respectively.

9. The method of claim 8, wherein the second set of bearing surfaces of the tube stop extend into the pair of tracks respectively and are secured in place by the pair of guide rails of the rotor knob.

10. The method of claim 9, wherein each of the pair of tracks comprises a first portion that receives one of the pair of rails of the rotor knob and a second portion that extends circumferentially from the first portion and receives one of the bearing surfaces of the tube stop.

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