Patent ID: 7861371

Claim:
A door damper comprising: a cylindrical body, which is open on a first side thereof and has a bumper on a second side side thereof; a return spring, which is inserted into the body; a spring holder, which supports the return spring; a piston, which is inserted into the spring holder; a check valve, which is installed between the spring holder and the piston; a piston rod, which is coupled to one side of the piston and protrudes outside the body; an oil distributor, which has the piston rod passing therethrough and is in contact with the piston; a sponge, which is in contact with the oil distributor, has the piston rod passing therethrough, and is fixed to a bushing; and a cover, which covers the first side of the body together with an oil seal contacting the bushing, wherein the piston includes a safety check valve therein, which is opened in cooperation with the check valve installed between the spring holder and the piston when a pressure higher than a design pressure is applied.