Strain actuated hydraulic holdback bar

摘要

A holdback bar for temporarily restraining an aircraft against the combined forces of engine thrust and catapult force prior to a catapult assisted launch of the aircraft which utilizes strain of a mechanical component to measure the level of combined forces. Housing stretch beyond a pre-determined amount actuates a floating trigger rod to lift a valve from its seat and permit escape of hydraulic fluid from a pressure chamber. The holdback bar includes a compensator for absorbing fluid volume changes caused by thermal expansion or contraction of the hydraulic fluid, and a rupture disk for limiting the pressure obtainable within the hydraulic fluid pressure chamber.