Abstract: A pre-tensioner arrangement applies tension to a safety belt in response to deceleration of a vehicle. A spring stores a force which is to be applied to the safety belt. A trigger mechanism comprises a lever which exhibits a mechanical advantage, one end of the lever engaging the spring, or an element associated with the spring, to retain the spring in a compressed state, and the other end of the lever engaging an over-dead-center linkage. An inertia mass is provided to engage the over-dead-center linkage to move it through the dead-center condition to release the lever and cause the spring to be released when severe deceleration is experienced.

Abstract: A brake unit for automatically adjusting slack between the brake surfaces of a railway brake has a pre-stressed spring which is released during the initial stroke of the brake piston in a braking application so as to expedite contact of the brake surfaces. After slack has been overcome, further movement of the piston in the braking direction will cause the force-transmitting components to be coupled together so that braking force is transmitted directly to the brake surfaces by subsequent movement of the piston in the braking direction. The release of the pre-stressed spring during the overcoming of slack in the brake rigging will increase the speed of the brake application with respect to the speed of the braking piston.

Abstract: A lock actuator attachment for a pneumatic service brake has a spindle follower for the service brake piston. A freely rotating nut is threaded on the spindle and a brake for preventing nut rotation is operated by a piston that may be pneumatically or hydraulically operated to hold the service brake in actuated position.