Vehicle seat belt with shock absorber - has spring loaded piston and restricted fluid flow for further absorber action

摘要

An outer casing (1) fixed to the vehicle has two chambers. The smaller diameter chamber (5) contains a piston (8) whose piston rod (10) passes through both chambers and outside the casing for attaching to the belt (14). The larger chamber (6) is filled with oil and has a piston (16) over the rod, forming a seal between the chambers. For normal use, a spring (23) around the rod in the lower chamber absorbs movement but a sudden shock compresses the spring against the larger piston and a spring catch (19, 20, 21) locks in a recess (24) in the piston rod to further belt forces move the pistons together. Oil passes from the upper chamber, through passages (26, 27) in the rod, into the lower chamber to provide further shock absorption.