SURGICAL END EFFECTOR WITH TWO SEPARATE COOPERATING OPENING FEATURES FOR OPENING AND CLOSING END EFFECTOR JAWS

1 . A surgical tool assembly, comprising:

a surgical end effector comprising:

a first jaw; and

a second jaw comprising a second jaw body portion and a second jaw mounting portion, said second jaw mounting portion movably coupled to said first jaw for selective movement relative thereto between an open position and closed positions and wherein said surgical instrument further comprises:

a closure member axially movable in response to closing and opening motions applied thereto, said closure member comprising at least one opening cam formed thereon, said at least one opening cam being configured to movably engage a corresponding cam surface formed on said second jaw body portion such that upon application of said opening motion to said closure member, said at least one opening cam movably engages said corresponding cam surface to move said second jaw to said open position and upon application of said closure motion to said closure member, said closure member engages said second jaw to move said second jaw to one of said closed positions.

2 . The surgical tool assembly of claim 1 , wherein said at least one opening cam comprises:

a first hook portion extending distally from a distal end of said closure member and being configured to cammingly engage a first one of said cam surfaces formed on said second jaw body portion; and

a second hook portion extending distally from said distal end of said closure member and being configured to cammingly engage a second one of said cam surfaces formed on said second jaw body portion.

3 . The surgical tool assembly of claim 1 , wherein said cam surface comprises a downwardly extending ramp surface formed on said second jaw body portion.

4 . The surgical tool assembly of claim 3 , wherein each said at least one opening cam comprises a camming end formed thereon configured to cammingly engage said corresponding ramp surface upon application of said opening motion to said closure member.

5 . The surgical tool assembly of claim 4 , wherein each said ramp surface comprises a ramp surface end and wherein each said camming end is configured to engage said ramp surface end of said corresponding ramp surface to retain said second jaw in a fully open position relative to said first jaw.

6 . The surgical tool assembly of claim 1 , further comprising secondary jaw opening means for applying additional opening motion to said second jaw.

7 . The surgical tool assembly of claim 6 , wherein said secondary jaw opening means comprises at least one secondary jaw opening member on said closure member configured to engage a corresponding jaw opening feature on said second jaw to apply said additional opening motion to said second jaw as said opening motion is applied to said closure member.

8 . The surgical tool assembly of claim 7 , wherein said secondary jaw opening feature comprises:

at least one first jaw opening tab integrally formed in said closure member and configured to contact a corresponding one of said corresponding jaw opening feature; and

at least one second jaw opening tab integrally formed in said closure member and configured to contact another corresponding one of said corresponding jaw opening feature.

9 . The surgical tool assembly of claim 6 , wherein said secondary jaw opening means comprises at least one biasing member configured to apply additional opening motion to said second jaw.

10 . The surgical tool assembly of claim 2 , wherein said first and second hook portions each comprise a compliant portion thereon.

11 . The surgical tool assembly of claim 10 , wherein said compliant portion comprises a compliant material attached to each of said first and second hook portions.

12 . The surgical tool assembly of claim 10 , wherein said at least one biasing member comprises a spring corresponding to each of said first and second hook portions and being attached thereto.

13 . A surgical tool assembly, comprising:

a surgical end effector comprising:

an elongate channel configured to operably support a surgical staple cartridge therein; and

an anvil comprising an anvil body and an anvil mounting portion, said anvil mounting portion pivotally supported on said elongate channel for selective movement relative thereto between an open position and closed positions and wherein said surgical instrument further comprises:

a closure member axially movable in response to closing and opening motions applied thereto, said closure member comprising at least one opening cam formed thereon, said at least one opening cam being configured to movably engage a corresponding cam surface formed on said anvil body portion such that upon application of said opening motion to said closure member, said at least one opening cam movably engages said corresponding cam surface to move said anvil to said open position and upon application of said closure motion to said closure member, said closure member engages said anvil to move said anvil to one of said closed positions.

14 . The surgical tool assembly of claim 13 , further comprising at least one tissue stop formed on said anvil body and wherein said at least one cam surface is located proximal to said at least one tissue stop.

15 . The surgical tool assembly of claim 13 , wherein said at least one opening cam comprises:

a first hook portion extending distally from a distal end of said closure member and being configured to cammingly engage a first one of said cam surfaces formed on said anvil body; and

a second hook portion extending distally from said distal end of said closure member and being configured to cammingly engage a second one of said cam surfaces formed on said anvil body.

16 . The surgical tool assembly of claim 15 , wherein said first and second hook portions each comprise a compliant portion thereon.

17 . The surgical tool assembly of claim 13 , wherein said first and second hook portions each comprise a compliant portion thereon.

18 . The surgical tool assembly of claim 13 , further comprising secondary anvil opening means for applying additional opening motion to said second jaw.

19 . The surgical tool assembly of claim 18 , wherein said anvil is pivotally coupled to said elongate channel for selective pivotal travel between said open and closed positions about a pivot axis and wherein said secondary anvil opening means is located proximal to said pivot axis.

20 . A surgical tool assembly, comprising:

a surgical end effector comprising:

an elongate channel configured to operably support a surgical staple cartridge therein; and

an anvil comprising an anvil body and an anvil mounting portion, said anvil mounting portion pivotally supported on said elongate channel for selective movement relative thereto between an open position and closed positions and wherein said surgical instrument further comprises:

a closure member axially movable between a fully actuated position corresponding to a fully closed one of said closed positions and an unactuated position corresponding to said open position, said closure member comprising a closure system configured to sequentially apply initial opening motions to said anvil and additional secondary motions to said anvil as said closure member is moved from said fully actuated position to said unactuated position.