Surgical instruments with positive jaw opening features
A surgical instrument that includes first and second jaws that are movable about a fixed jaw axis between a fully open position and a fully closed position relative to each other. A closure member is configured to move the first and second jaws from the fully open position to the fully closed position when the closure member is moved in a first direction. At least one jaw opening cam is supported for movement relative to the closure member and the first and second jaws. Each of the jaw opening cams is configured to apply an opening motion to the first and second jaws when the closure member is moved in a second direction.
1. A surgical instrument, comprising:
a surgical end effector comprising first and second jaws operably interfacing with each other to move about a fixed jaw axis between a fully open position and a fully closed position relative to each other;
a shaft assembly operably interfacing with said surgical end effector, said shaft assembly comprising a closure member configured to move said first and second jaws from said fully open position to said fully closed position when said closure member is moved in a first direction and wherein said surgical instrument further comprises:
at least one jaw opening cam stretchably coupled to said closure member by a distally-extending spring, each said at least one jaw opening cam configured to apply an opening motion to said first and second jaws when said closure member is moved in a second direction.
2. The surgical instrument of claim 1 , wherein each of said at least one jaw opening cam is movably coupled to said closure member.
3. The surgical instrument of claim 2 , wherein each of said at least one jaw opening cam is movably coupled to said closure member by a tension spring.
4. The surgical instrument of claim 1 , wherein said first jaw comprises a first arcuate cam surface that corresponds to each of said at least one jaw opening cam and wherein said second jaw comprises a second arcuate cam surface that corresponds to each of said first arcuate cam surface and curves in a direction away from said first arcuate cam surface.
5. The surgical instrument of claim 4 , wherein each of said at least one jaw opening cam has a wedge shape that is configured to simultaneously engage said corresponding first and second arcuate cam surfaces.
6. The surgical instrument of claim 1 , wherein said first jaw comprises an elongate channel that is configured to removably support a surgical staple cartridge therein and wherein said second jaw comprises an anvil.
7. The surgical instrument of claim 1 , wherein said surgical end effector is coupled to said shaft assembly by an articulation joint for selective articulation about an articulation axis that is transverse to a shaft axis defined by said shaft assembly.
8. The surgical instrument of claim 1 , wherein said first jaw comprises a first closure cam surface and wherein said second jaw comprises a second closure cam surface, each of said first and second closure cam surfaces positioned for camming contact with said closure member as said closure member moves in said first direction to apply closure motions to said first and second jaws.
9. The surgical instrument of claim 6 , wherein said shaft assembly further comprises:
a firing member assembly configured for axial movement in said first direction upon application of a firing motion thereto; and
an end effector firing member operably coupled to said firing member assembly configured to sever tissue and fire staples out of a surgical staple cartridge that is operably supported in said elongate channel when said firing member assembly is moved in said first direction a predetermined firing distance.
10. A surgical instrument, comprising:
a surgical end effector comprising first and second jaws operably interfacing with each other to move about a fixed jaw axis between a fully open position and a fully closed position relative to each other;
a shaft assembly operably interfacing with said surgical end effector, said shaft assembly comprising a closure member configured to move said first and second jaws from said fully open position to said fully closed position when said closure member is moved in a first direction and wherein said surgical instrument further comprises:
a first wedge-shaped cam movably coupled to said closure member by a first stretchable coupler for movement relative to said closure member; and
a second wedge-shaped cam movably coupled to said closure member by a second stretchable coupler for movement relative to said closure member, said first and second wedge-shaped cams applying opening motions to said first and second jaws when said closure member is moved in a second direction.
11. The surgical instrument of claim 10 , wherein said first wedge-shaped cam is oriented between a first arcuate cam surface on said first jaw and a second arcuate surface on said second jaw and wherein said second wedge-shaped cam is oriented between another first arcuate cam surface on said first jaw and another second arcuate cam surface on said second jaw.
12. The surgical instrument of claim 10 , wherein said first stretchable coupler comprises a first tension spring and wherein said second stretchable coupler comprises a second tension spring.
13. The surgical instrument of claim 10 , wherein said first jaw comprises an elongate channel that is configured to removably support a surgical staple cartridge therein and wherein said second jaw comprises an anvil.
14. The surgical instrument of claim 10 , wherein said surgical end effector is coupled to said shaft assembly by an articulation joint for selective articulation about an articulation axis that is transverse to a shaft axis defined by said shaft assembly.
15. The surgical instrument of claim 13 , wherein said shaft assembly further comprises:
a firing member assembly configured for axial movement in said first direction upon application of a firing motion thereto; and
an end effector firing member operably coupled to said firing member assembly configured to sever tissue and fire staples out of a surgical staple cartridge that is operably supported in said elongate channel when said firing member assembly is moved in said first direction a predetermined firing distance.
16. The surgical instrument of claim 10 , wherein said first jaw comprises a first closure cam surface and wherein said second jaw comprises a second closure cam surface, each of said first and second closure cam surfaces positioned for camming contact with said closure member as said closure member moves in said first direction to apply closure motions to said first and second jaws.
17. A surgical instrument, comprising:
a surgical end effector comprising first and second jaws operably interfacing with each other to move about a fixed jaw axis between a fully open position and a fully closed position relative to each other;
a shaft assembly operably interfacing with said surgical end effector, said shaft assembly comprising a closure member configured to move said first and second jaws from said fully open position to said fully closed position when said closure member is moved in a first direction and wherein said surgical instrument further comprises:
at least one jaw opening cam supported between corresponding portions of said first and second jaws; and
means for stretchably coupling each of said at least one jaw opening cam to said closure member such that each of said at least one jaw opening cam is located distal to said closure member, said means for stretchably coupling applying a tension force to said at least one jaw opening cam as said closure member is moved in a second direction.
18. The surgical instrument of claim 17 , wherein said first jaw comprises a first closure cam surface and wherein said second jaw comprises a second closure cam surface, each of said first and second closure cam surfaces positioned for camming contact with said closure member as said closure member moves in said first direction to apply closure motions to said first and second jaws.
19. The surgical instrument of claim 17 , wherein said closure member is axially movable between an unactuated position corresponding to said fully open position to a fully actuated position corresponding to said fully closed position and wherein each of said at least one jaw opening cam is distal to said closure member when said closure member is in said unactuated position.
20. The surgical instrument of claim 17 , wherein said first jaw comprises an elongate channel that is configured to removably support a surgical staple cartridge therein and wherein said second jaw comprises an anvil.
21. A surgical instrument, comprising:
an end effector comprising a first jaw and a second jaw, wherein said first jaw and said second jaw are configured to pivot about an axis between an open position and a closed position, wherein said first jaw comprises a first sidewall and a second sidewall;
a shaft assembly comprising a closure member configured to move said first jaw and said second jaw from said open position to said closed position upon distal movement of said closure member;
a first cam flexibly coupled to said closure member by a first stretchable coupler; and
a second cam flexibly coupled to said closure member by a second stretchable coupler, wherein said first cam is configured to apply opening motions to said first sidewall and said second cam is configured to apply opening motions to said second sidewall to move said first jaw and said second jaw toward the open position upon proximal movement of said closure member.