Abstract: An insertion device is provided for use with surgical tissue fastening apparatus. The insertion device includes a head having an atraumatic leading surface and a shaft extending proximally therefrom. The shaft includes attachment structure for detachable engagement with surgical tissue fastening apparatus. The atraumatic leading structure aids in insertion of the surgical apparatus during a stapling procedure. The shaft, in combination with the head, can also be dimensioned and configured to prevent activation of a surgical tissue fastening apparatus while installed thereon. The insertion device can also include structure to protect and retain fasteners contained within the surgical tissue fastening apparatus. Further, the disclosed insertion devices can be constructed so as to reduce overall weight and alleviate suction effects associated with insertion and retraction.

Abstract: An anvil assembly for a surgical fastening instrument is disclosed. The anvil is constructed to pivot relative to an anvil shaft to facilitate movement of the anvil and instrument during use. The anvil also has an improved surface for severing structures and a sloped surface for guiding a knife during use.

Abstract: An actuator having a spring biased button abutting a first electric switch operator button and a flange spaced from an operator button of a second electric switch is driven by a pressure sensing bellows against a Belleville snap spring, the actuator moving abruptly against an intermediate stop upon breakover of the snap spring to operate the first switch, the bellows subsequently driving the actuator and intermediate stop coincidentally against a second Belleville snap spring, and the actuator moving abruptly against a second stop upon breakover of the second snap spring to actuate a second electric switch and depress the spring biased button. Adjustment means are provided for adjusting the range for each Belleville snap spring to provide distinct pressure set points and independent electric circuits, and to adjust both set points simultaneously.