Endoscopic instrument with bi-laterally widened cam-slot at end effector

An endoscopic instrument includes a tubular member having a proximal end and a distal end, a clevis at the distal end of the tubular member, and an end effector assembly mounted on the clevis. A control member extends through the tubular member and includes a cam-pin coupled to the distal end thereof. The end effectors are controlled with a cam-pin and cam-slot arrangement, with the end effectors including the cam-slot and such cam-slot having a proximal end slot bilaterally widened to permit the cam-pin additional movement therein. When the cam-pin is retracted to move the end effectors into a closed positions and then further retracted into the bilaterally widened area, the end effectors can rotate together in the same direction to facilitate movement through a rigid bend in an endoscope.