Patent ID: 8469163

Claim:
A rotary damper comprising a valve mechanism, wherein the valve mechanism comprises an operating chamber through which fluid can pass, a valve chamber formed adjacently to the operating chamber, a valve body which is placed in the valve chamber, and a first spring mounted in the operating chamber, wherein the damper is structured and arranged to apply fluid pressure behind the valve body which increases in proportion to a load, wherein the valve body is structured and arranged to move forward into the operating chamber upon receiving the pressure of the fluid, through a flow path formed between an inner peripheral surface of a peripheral wall of the operating chamber and an outer peripheral surface of the valve body, wherein the valve mechanism further comprises a flow path which is formed by the forward movement of the valve body, wherein the damper is structured and arranged such that the fluid moves only through the flow path when the valve body moving from the valve chamber to the operating chamber, wherein a length of the flow path becomes longer as the valve body moves forwardly, and wherein an area of the flow path becomes smaller as the valve body moves forwardly when the pressure of the fluid is less than a predetermined value.