Ratchet release mechanism for hand held instruments

Abstract

A hand held surgical instrument for grasping and clamping tissue is disclosed. The surgical instrument has a handle body assembly and an elongated shaft. The shaft is connected to the handle body assembly at a proximal end and has an end effector at a distal end. The end effector is operably coupled to an actuation member extending from the handle body. The actuation member is moveable toward and away from the handle body to open and close the end effector. A locking tab is located on the handle body assembly and is moveable between a locked position and an unlocked position. A locking rod is movably engaged with a hole in the locking tab. When the locking tab is in the unlocked position, the actuation member is free to move towards and away from the handle body assembly to open and close the end effector. When the locking tab is in the locked position, movement to open the actuation member is prevented. The handle body assembly also has release trigger extending from the handle body assembly and operably coupled to the locking tab. The release trigger is moveable from a first position spaced away from the handle body to a second position adjacent to the handle body. The release trigger is normally biased toward the first position and is reciprocable, when initially squeezed toward the handle body assembly from the first position, to the second position, and subsequently released from the second position back to the first position. Consecutive reciprocations of the release trigger alternates the locking tab between the locked position and the unlocked position.