Patent attributes
Surgical instruments, such as clamping and cutting instruments, are provided. In one aspect, a surgical stapling instrument comprises first and second jaws and a drive member configured to move in a distal direction through at least one of the jaws. The instrument further includes a locking member movable between a first position permitting distal translation of the drive member, and a second position impeding distal translation of the drive member, and a switch movable from a proximal position to a distal position. When the switch is in the proximal position, it releasably maintains the locking member in the first position, and when the switch is in the distal position, it allows the locking member to move to the second position. This inhibits or prevents actuation of a knife when there is a spent or previously fired cartridge loaded in the instrument.