Multi-stroke mechanism with automatic end of stroke retraction

• US 7,083,075 B2
• Filed: 02/07/2005
• Issued: 08/01/2006
• Est. Priority Date: 09/29/2003
• Status: Expired due to Term

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Inventors: Shelton, Frederick E. IV, Swayze, Jeffrey S., Hoffman, Douglas B., Doll, Kevin Ross
• Primary Examiner(s): Smith, Scott A.
• Assistant Examiner(s): CHUKWURAH, NATHANIEL C
• Application Number:
  US11/052,632
• Publication Number:
  US 20050178813A1
• Time in Patent Office: 540 Days
• Field of Search: 227/19, 227/175.2, 227/176.1, 227/177.1, 227/178.1, 227/181.1
• US Class Current: 227/176.1
• CPC Class Codes: A61B 17/07207 the staples being applied sequentially
• CPC Class Codes: A61B 17/2909 Handles
• CPC Class Codes: A61B 2017/2923 Toothed members, e.g. rack and pinion
• CPC Class Codes: A61B 2017/2925 Pistol grips

Abstract

A surgical stapling and severing instrument particularly suited to endoscopic procedures incorporates a handle that produces separate closing and firing motions to actuate an end effector. In particular, the handle produces multiple firing strokes in order to reduce the required amount of force required to fire (i.e., staple and sever) the end effector. A linked transmission reduces the required handle longitudinal length, yet achieves a rigid, strong configuration when straightened for firing. A traction biased firing mechanism avoids binding in driving this straightened linked rack in cooperation with an anti-backup mechanism, with a lockout mechanism that prevents releasing the closure trigger during firing. Furthermore, an external indicator gives feedback to the surgeon as to how far firing has progressed, as well as providing a manual retraction capability.

Claims

1. A surgical instrument, comprising:

a staple applying assembly;

a shaft connected to the elongate channel of the staple applying assembly;

a firing member slidingly receiving by the shaft to transfer a firing motion to the staple applying assembly;

a retraction spring biasing the firing member proximally away from the shaft;

an anti-backup mechanism having a locking member biased into a binding, nonperpendicular contact with the firing member;

an anti-backup release lever positionable to move the locking member of the anti-backup mechanism into nonbinding, perpendicular contact with the firing member; and

a firing mechanism responsive to full firing travel of the firing member to position the anti-backup release lever.

2. The surgical instrument of claim 1, wherein the firing member includes a rack, the surgical instrument further comprising a gear mechanism coupled to the rack operatively configured to rotate a cam into distally moving contact with the proximal end of the anti-backup release lever in response to full firing travel of the rack.

3. The surgical instrument of claim 2, wherein the gear mechanism comprises an idler gear engaged to the rack and sized to make one revolution in response to full firing travel of the rack, and comprises a cam wheel containing the cam responsive to the idler gear to distally move the anti-backup release lever.

4. The surgical instrument of claim 1, further comprising a handle that constrains movement of the anti-backup release lever, wherein the anti-backup release lever has a distal end and a proximal end, the anti-backup release lever constrained such that the distal end moves distally and downwardly into contact with the anti-backup mechanism in response to the proximal end being distally displaced, wherein the firing member includes a rack containing a proximally positioned tang aligned to distally move the proximal end of the anti-backup release lever.

5. The surgical instrument of claim 4, wherein the distal portion includes a forward pin urged downwardly into a locking structure by a compression spring when distally moved, wherein the handle is operatively configured to hold the end effector closed during firing strokes with a distally advanced closure yoke, the closure yoke including an unlocking feature aligned when released to unlock the anti-backup mechanism by raising the forward pin out of the locking structure.

6. A surgical instrument, comprising:

an end effector responsive to a longitudinal firing motion to perform a surgical operation;

a shaft connected to the end effector;

a firing member slidingly receiving by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position;

a firing mechanism responsive to a plurality of firing strokes to advance the firing member down the shaft;

a retraction spring biasing the firing member proximally away from the shaft;

an anti-backup mechanism engageable to the firing member in response to a proximal movement thereof; and

an anti-backup release mechanism operatively configured to lock the anti-backup mechanism in a disengaged state upon reaching full firing travel of the firing member.

7. The surgical instrument of claim 6, wherein the anti-backup mechanism comprises:

a locking plate including an aperture circumferentially encompassing the firing member, the locking plate pivotal between a locking position wherein the aperture lockingly engages the firing member and an unlocking position wherein the aperture slidingly engages the firing member,

an anti-backup spring biasing the locking plate to the locking position; and

an anti-backup release lever positioned to oppose the bias of the anti-backup spring.

8. The surgical instrument of claim 6, wherein the handle is operatively configured to hold the end effector closed during firing strokes with a distally advanced closure yoke, the closure yoke including an unlocking feature aligned when released to unlock the anti-backup mechanism.

9. The surgical instrument of claim 6, further comprising a handle wherein the firing member includes a rack contained in the handle and attached to the retraction spring, the anti-backup release mechanism coupled to the rack to distally move the anti-backup release mechanism.

10. The surgical instrument of claim 9, wherein the anti-backup release member comprises an anti-backup release lever having a distal end and a proximal end, the anti-backup release lever constrained within the handle such that the distal end moves distally and downwardly into contact with the anti-backup mechanism in response to the proximal end being distally displaced.

11. The surgical instrument of claim 10, wherein the rack includes a proximally positioned tang aligned to distally move the proximal end of the anti-backup release lever.

12. The surgical instrument of claim 10, further comprising a gear mechanism coupled to the rack, operatively configured to rotate a cam into distally moving contact with the proximal end of the anti-backup release lever in response to full firing travel of the rack.

13. The surgical instrument of claim 12, wherein the gear mechanism comprises an idler gear engaged to the rack and sized to make one revolution in response to full firing travel of the rack, and comprises a cam wheel containing the cam responsive to the idler gear to distally move the anti-backup release lever.

14. The surgical instrument of claim 9, wherein the end effector comprises:

an elongate channel connected to the shaft;

an anvil pivotally coupled to said elongate channel for clamping tissue; and

a staple cartridge received in said elongate channel;

wherein said firing member distally terminates in a firing bar operably configured to actuate the staple cartridge to form staples in the clamped tissue.

16. The surgical instrument of claim 10, wherein the firing member includes a proximally positioned tang aligned to distally move the proximal end of the anti-backup release lever.

17. The surgical instrument of claim 11, wherein the firing member further comprises a rack containing the tang.

18. The surgical instrument of claim 12, further comprising a handle having a downward grip, wherein the rack further comprises a link rank downwardly bendable into the downward grip.

19. The surgical instrument of claim 10, further comprising a gear mechanism coupled to the rack operatively configured to rotate a cam wheel into distally moving contact with the proximal end of the anti-backup release lever in response to full firing travel of the rack.

20. The surgical instrument of claim 10, wherein the firing member includes a rack, the surgical instrument further comprising a gear mechanism coupled to the rack operatively configured to rotate a cam into distally moving contact with the proximal end of the anti-backup release lever in response to full firing travel of the rack.

15. A surgical instrument, comprising:

an end effector responsive to a longitudinal firing motion to perform a surgical operation, comprising an elongate channel, an anvil pivotally coupled to the elongate channel for clamping tissue, and a staple cartridge received in the elongate channel;

a shaft connected to the elongate channel of the end effector;

a firing member slidingly received by the shaft to transfer the firing motion to the end effector to actuate the staple cartridge and to sever the clamped tissue;

a retraction spring biasing the firing member proximally away from the shaft;

a firing trigger;

a firing mechanism responsive to a plurality of firing strokes of the firing trigger selectively engaging a pawl into engagement with the firing member to effect full firing travel thereof;

an anti-backup mechanism engageable to the firing member in response to a proximal movement thereof, comprising;

a locking plate including an aperture circumferentially encompassing the firing member, the locking plate pivotal between a locking position wherein the aperture lockingly engages the firing member and an unlocking position wherein the aperture slidingly engages the firing member,

an anti-backup spring biasing the locking plate to the locking position, and

an anti-backup release lever positioned to oppose the bias of the anti-backup spring by having a distal end and a proximal end, the anti-backup release lever constrained such that the distal end moves distally and downwardly into contact with the anti-backup mechanism in response to the proximal end being distally displaced; and

an anti-backup release mechanism operatively configured to lock the anti-backup mechanism in a disengaged state upon reaching full firing travel of the firing member.

21. The surgical instrument of claim 15, wherein the gear mechanism comprises an idler gear engaged to the rack and sized to make one revolution in response to full firing travel of the rack, and comprises a cam wheel containing the cam responsive to the idler gear to distally move the anti-backup release lever.