Surgical stapling instrument with a geared return mechanism
View Patent ↗A surgical instrument including a firing drive configured to selectively advance a firing member and/or cutting member relative to an end effector and, in addition, a reversing drive configured to selectively retract the firing member and/or cutting member relative to the end effector. The firing drive can include a pawl which can be selectively engaged with the firing member in order to advance the firing member, wherein the pawl can be disengaged from the firing member when the reversing drive is engaged with the firing member. The reversing drive can include a gear train having a first gear operably engaged with the firing member and, in addition, a second gear operably engaged with the first gear, wherein the second gear can be selectively operable with the trigger such that an actuation of the trigger can retract the firing member and/or cutting element via the first and second gears.
1. A surgical instrument, comprising:
an end effector;
a firing member;
a trigger;
a firing drive selectively engageable with said firing member, wherein said firing drive is configured to advance said firing member relative to said end effector upon an actuation of said trigger; and
a reversing drive selectively engageable with said firing member, wherein said reversing drive includes a gear configured to retract said firing member relative to said end effector upon a subsequent actuation of said trigger.
2. The surgical instrument of claim 1 , wherein said gear includes a first gear, wherein said trigger includes a gear portion, and wherein said reversing drive further includes:
a second gear operably engaged with said first gear; and
a third gear operably engaged with said trigger gear portion, wherein said second gear is selectively engageable with said third gear.
3. The surgical instrument of claim 2 , wherein said second gear is not operably engaged with said third gear when said firing drive is engaged with said firing member.
4. The surgical instrument of claim 2 , wherein said second gear is operably engageable with said third gear such that said subsequent actuation of said trigger can rotate said third gear, said second gear, and said first gear and retract said firing member.
5. The surgical instrument of claim 4 , wherein said reversing drive further includes:
a key pin selectively movable between a first position and a second position, wherein said key pin is not operably engaged with said third gear when said key pin is in said first position, and wherein said key pin is operably engaged with said second gear and said third gear when said key pin is in said second position; and
a spring configured to bias said key pin into said second position.
6. The surgical instrument of claim 5 , wherein said reversing drive further includes an actuator configured to position said key pin in said first position when said firing drive is operably engaged with said firing member, and wherein said actuator is movable into an actuated position to allow said spring to bias said key pin into said second position and thereby operably engage said reversing drive with said firing member.
7. The surgical instrument of claim 6 , wherein said actuator is further configured to disengage said firing drive from said firing member when said actuator is moved into said actuated position.
8. The surgical instrument of claim 2 , wherein said reversing drive further includes a clutch configured to operably engage and disengage said second gear and said third gear, wherein said clutch includes a key pin operably engaged with said second gear and a dog extending from said third gear, wherein said dog is configured to permit said key pin to rotate relative to said third gear in a first direction, and wherein said dog is configured to rotate said key pin in a direction opposite said first direction.
9. The surgical instrument of claim 1 , further comprising an anti-backup mechanism configured to substantially prevent said firing member from being retracted relative to said end effector prior to said subsequent actuation of said trigger.