Abstract: A surgical instrument comprises a body, shaft, and end effector. The shaft couples the end effector and body together. The end effector comprises an anvil and lower jaw configured to receive a surgical staple cartridge. The anvil is configured to pivot toward and away from the staple cartridge and lower jaw. The shaft assembly comprises a knife member configured to longitudinally translate to thereby substantially simultaneously cut clamped tissue and staple the severed tissue. The end effector may comprise lockout features configure to prevent longitudinal translation of the knife member. The end effector or staple cartridge may comprise lockout bypass features configured to prevent lockout of the knife member. These lockout bypass features may operate to permit longitudinal translation of the knife member once or multiple times. The end effector may comprise features configured to ensure proper alignment of the anvil relative to the staple cartridge.

Abstract: Apparatus for resisting rearward movement of a tow truck or wrecker while winching a vehicle up to towing position in back of the wrecker comprises a stiff leg attachment which is raised and lowered by toggle linkages that move overcenter and engage against a stop to support the stiff leg attachment in lowered position during winching.

Abstract: A wrecker for towing disabled automobiles and the like has attachment fittings on the rear bumper each for securing a scotch block chain and a snatch block to the bumper at the same location on the bumper. When an automobile is being winched into towing position, buckling forces exerted on the bumper by tension developed in the scotch block chains are counterbalanced by forces exerted on the bumper by tension developed in the winching cable which is passed around pulleys on the snatch blocks.