Firing system features for surgical stapler

A surgical stapling instrument comprising:

• (a) a shaft extending along a longitudinal axis to a distal end;
• (b) an end effector operatively coupled with the shaft, wherein the end effector includes:
• (i) a first jaw having an anvil, and
• (ii) a second jaw, wherein the first and second jaws are operable to clamp tissue therebetween;
• and
• (c) a stapling assembly supported by the second jaw of the end effector, wherein the stapling assembly includes:
• (i) a plurality of staples,
• (ii) a staple actuator translatable distally through the stapling assembly along the longitudinal axis, and
• (iii) a first driver assembly, wherein the first driver assembly includes:
• (A) a laterally-opposed pair of distal drivers that receive respective staples of the plurality of staples,
• (B) a proximal driver that receives a respective staple of the plurality of staples, and
• (C) a cam surface,
• wherein the staple actuator is configured to engage the cam surface of the first driver assembly during distal translation of the staple actuator to drive the respective staples into contact with the anvil of the first jaw,
• wherein the staple actuator and the cam surface are configured such that, when the respective staples contact the anvil of the first jaw, the engagement between the staple actuator and the cam surface of the first driver assembly is centered at a location along the cam surface distal of a centroid of the first driver assembly,
• wherein the stapling assembly further includes:
• (a) an elongate slot extending longitudinally for receiving a portion of the staple actuator;
• and
• (b) at least one stapling assembly support member extending laterally inwardly from one side of the elongate slot toward an opposing side of the elongate slot,
• wherein the at least one stapling assembly support member is configured to be deflected laterally outwardly by the portion of the staple actuator during distal translation of the staple actuator.

A surgical stapling instrument comprising:

• (a) a shaft extending along a longitudinal axis to a distal end;
• (b) an end effector operatively coupled with the shaft, wherein the end effector includes:
• (i) a first jaw having an anvil, and
• (ii) a second jaw, wherein the first and second jaws are operable to clamp tissue therebetween;
• and
• (c) a stapling assembly supported by the second jaw of the end effector, wherein the stapling assembly includes:
• (i) a plurality of staples,
• (ii) a staple actuator translatable distally through the stapling assembly along the longitudinal axis, and
• (iii) a first driver assembly, wherein the first driver assembly includes:
• (A) a laterally-opposed pair of distal drivers that receive respective staples of the plurality of staples,
• (B) a proximal driver that receives a respective staple of the plurality of staples, and
• (C) a cam surface,
• wherein the staple actuator is configured to engage the cam surface of the first driver assembly during distal translation of the staple actuator to drive the respective staples into contact with the anvil of the first jaw,
• wherein the staple actuator and the cam surface are configured such that, when the respective staples contact the anvil of the first jaw, the engagement between the staple actuator and the cam surface of the first driver assembly is centered at a location along the cam surface distal of a centroid of the first driver assembly,
• wherein the stapling assembly further includes at least one driver retention member extending laterally inwardly to engage a portion of the first driver assembly, wherein the at least one driver retention member is configured to be deflected laterally outwardly by the portion of the first driver assembly during distal translation of the staple actuator.

A stapling assembly for a surgical stapling instrument, comprising:

• (a) a plurality of staples;
• (b) a staple actuator translatable distally through the stapling assembly along a longitudinal axis;
• and
• (c) a driver assembly, wherein the driver assembly includes:
• (i) a laterally-opposed pair of distal drivers that receive respective staples of the plurality of staples,
• (ii) a proximal driver that receives a respective staple of the plurality of staples, wherein the proximal driver is positioned laterally between the pair of distal drivers, wherein at least a portion of the proximal driver is proximal of each of the pair of distal drivers, wherein the proximal driver is oriented substantially parallel relative to at least one of the pair of distal drivers, and
• (iii) a cam surface,
• wherein the staple actuator is configured to engage the cam surface of the driver assembly during distal translation of the staple actuator to drive the respective staples upwardly,
• wherein the staple actuator and the cam surface are configured such that, when the respective staples are driven between 0.05 inch and 0.065 inch upwardly from a starting position, the engagement between the staple actuator and the cam surface of the first driver assembly is centered at a location along the cam surface distal of a centroid of the first driver assembly.

A method of operating an apparatus comprising (i) an end effector having an anvil and a jaw, and (ii) a stapling assembly supported by the jaw and having a staple actuator and a driver assembly having (A) a laterally-opposed pair of distal drivers that receive respective staples, (B) a proximal driver that receives a respective staple wherein the proximal driver is positioned laterally between the pair of distal drivers, wherein at least a portion of the proximal driver is proximal of each of the pair of distal drivers, wherein the proximal driver is oriented substantially parallel relative to at least one of the pair of distal drivers, and (C) a cam surface, the method comprising:

• (a) translating the staple actuator distally through the stapling assembly along a longitudinal axis;
• (b) engaging the staple actuator with the cam surface of the driver assembly to drive the respective staples into contact with the anvil;
• (c) applying downward forces to distal ends of the distal drivers via the contact between the anvil and the respective staples;
• and
• (d) simultaneously with the act of applying downward forces, applying an upward, distal force to the cam surface of the driver assembly via the staple actuator at a location along the cam surface distal of a centroid of the driver assembly, wherein the location is positioned below the centroid and spaced apart therefrom by a vertical distance, wherein the cam surface is oriented at an angle relative to a horizontal reference plane, wherein the vertical distance and the angle have a ratio of between approximately 0.025:25 and approximately 0.1:15.