Surgical stapling instrument incorporating a multi-stroke firing mechanism with return spring rotary manual retraction system

The 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 received by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position;
• a rack attached to the firing member;
• a firing mechanism operably configured to engage and distally advance the rack during a firing stroke and to disengage thereafter;
• a gear mechanism engaged to the rack;
• a handle containing the rack, firing mechanism and gear mechanism;
• and
• a retraction member mounted for rotation external to the handle and coupled for rotation to the gear mechanism;
• wherein the gear mechanism further comprises an idler gear to the rack, the idler gear rotating in a first direction when the rack moves distally and in a second direction when the rack moves proximally, the idler gear coupled to a one-way clutch that is in turn coupled to the retraction member, the one-way clutch operably configured to disengage when the retraction member is rotated in the first direction relative to the idler gear.

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 received by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position;
• a rack attached to the firing member;
• a firing mechanism operably configured to engage and distally advance the rack during a plurality of firing strokes to advance the firing member down the shaft and to disengage from the rack thereafter;
• a gear mechanism engaged to the rack;
• a handle containing the rack, firing mechanism and gear mechanism;
• a retraction spring proximally attached to the rack to urge retraction thereof;
• a retraction member mounted for rotation external to the handle and coupled for rotation to the gear mechanism for manually assisting the retraction spring;
• 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 disengage the anti-backup mechanism;
• wherein actuating the gear retraction lever is coupled to activate the anti-backup release mechanism;
• 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;
• wherein the gear retraction lever includes a cam member positioned to distally advance the anti-backup release lever.

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 received by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position;
• a rack attached to the firing member;
• a firing mechanism operably configured to engage and distally advance the rack during a plurality of firing strokes to advance the firing member down the shaft and to disengage from the rack thereafter;
• a gear mechanism engaged to the rack;
• a handle containing the rack, firing mechanism and gear mechanism;
• a retraction spring proximally attached to the rack to urge retraction thereof;
• a retraction member mounted for rotation external to the handle and coupled for rotation to the gear mechanism for manually assisting the retraction spring;
• 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 disengage the anti-backup mechanism, wherein actuating the gear retraction lever is coupled to activate the anti-backup release mechanism;
• wherein the gear mechanism further comprises:
• an idler gear engaged to the rack and sized to make one revolution in response to full firing travel of the rack,
• a cam wheel responsive to the idler gear to distally move the anti-backup release lever at the end of full firing travel, and
• a transmission gear engaged to the idler gear and containing the ratchet gear.

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 received by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position;
• a rack attached to the firing member;
• a firing mechanism operably configured to engage and distally advance the rack during a plurality of firing strokes to advance the firing member down the shaft and to disengage from the rack thereafter;
• a gear mechanism engaged to the rack;
• a handle containing the rack, firing mechanism and gear mechanism;
• a retraction spring proximally attached to the rack to urge retraction thereof;
• a retraction member mounted for rotation external to the handle and coupled for rotation to the gear mechanism for manually assisting the retraction spring;
• an anti-backup mechanism engageable to the firing member in response to a proximal movement thereof;
• an anti-backup release mechanism operatively configured to disengage the anti-backup mechanism, wherein actuating the gear retraction lever is coupled to activate the anti-backup release mechanism;
• and
• a handle containing the rack, firing mechanism, and gear mechanism and further comprising a hold-up structure, wherein the gear retraction lever further comprises a hub including a recess sized to receive the ratcheting gear, a pawl attached to pivot in the recess, and the hold-up structure positioned to hold the pawl above the ratcheting gear when the gear retraction lever is unactuated.

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 received by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position;
• and
• a handle comprising:
• a firing trigger,
• a rack attached to the firing member;
• a firing mechanism responsive to a plurality of firing strokes from the firing trigger to advance the rack and thus the firing member down the shaft;
• a retraction spring biasing the firing member proximally away from the shaft;
• an anti-backup mechanism engageable to bind the firing member in response to a proximal movement thereof;
• an anti-backup release mechanism operatively configured to disengage the anti-backup mechanism for retraction;
• and
• a manual retraction mechanism comprising an idler gear engaged to the rack and coupled by a one-way clutch to an externally accessible actuator;
• wherein the one-way clutch of the manual retraction mechanism further comprises a ratchet gear coupled for rotation to the idler gear to rotate in a first direction when the rack moves distally and a second direction when the rack moves proximally, and comprises a retraction pawl connected to the externally accessible actuator, the retraction pawl positioned to engage the ratchet gear as the externally accessible actuator is actuated to turn the ratchet gear in the second direction to retract the rack and firing member.