Feature to lock knob of tissue stapler

A surgical stapling instrument for applying a plurality of surgical staples to tissue, comprising:

• (a) a stapling head assembly, wherein said stapling head assembly comprises:
• (i) a staple holder containing a plurality of surgical staples,
• (ii) an anvil for forming the staples, said anvil being mounted on an anvil shaft slidably supported for movement relative to said stapling head assembly to allow tissue to be clamped between said anvil and said staple holder, and
• (iii) a staple driver operable to drive the staples from said staple holder into tissue and against said anvil;
• (b) an actuator handle assembly, comprising:
• (i) an adjusting knob that is rotatable to control motion of said anvil, and
• (ii) a second actuator operable to control motion of said staple driver;
• (c) a shaft assembly coupling said stapling head assembly with said actuator handle assembly;
• (d) a safety latch responsive to said adjusting knob, wherein the safety latch is configured to prevent operation of said second actuator when the gap between said anvil and said staple holder is outside a predetermined distance;
• and
• (e) a locking member responsive to said safety latch, wherein the locking member is operable to prevent rotation of the adjusting knob when the safety latch is positioned to allow operation of the second actuator.

A method of operating a surgical stapling instrument to apply a plurality of surgical staples to tissue, comprising:

• (a) rotating a first actuator to move an anvil for forming staples toward a staple holder containing a plurality of staples to a set distance between the anvil and the staple holder;
• (b) pivoting a safety latch when the anvil gap is at the set distance, to enable operation of a second actuator operable to control motion of a staple driver that engages and drives the staples from said staple holder into the tissue and against said anvil;
• (c) locking rotation of the first actuator when the safety latch is pivoted to allow operation of the second actuator;
• and
• (d) firing said staple driver by operating said second actuator to drive the staples from the staple holder into tissue and against said anvil.