US Patent 7887031 Stay damper

A stay damper comprises a cylinder (1) in which a gas is charged, a piston rod (2) which projects under a pressure of the gas in the cylinder (1), and a stopper (10) which locks contraction of the piston rod (2) in an elongated position. The stopper (10) displaces between a lock position which locks contraction of the piston rod (2) and a release position which permits contraction of the piston rod (2) according to directional operation forces applied by an operator. The stopper (10) comprises a restricting member (12, 13) which holds the stopper (10) in the lock position when it is in the lock position and holds the stopper (10) in the release position when it is in the release position. Since the locking operation of the stopper (10) is performed manually, the releasing operation thereof is easily understood by the operator.