Patent ID: 7740159

Claim:
A surgical instrument comprising: a handle assembly; a distal member distally coupled to said handle assembly and configured to support a surgical tool; a pneumatically powered motor configured to generate at least one actuation motion upon receipt of at least one pneumatic signal from a source of pneumatic power fluidically coupled to said pneumatically powered motor; a drive shaft assembly communicating with said pneumatically powered motor and the surgical tool for transmitting said at least one actuation motion to the surgical tool; and a power assist trigger operably supported by said handle assembly: and a linkage assembly comprising: a first gear operably attached to said output shaft of said pneumatically powered motor; a threaded shaft in threaded engagement with a portion of said power assist trigger such that when said power assist trigger is manually actuated, said threaded shaft is rotated; and a second gear operably coupled to said threaded shaft and in threaded engagement with said first gear.