Patent ID: 7066308

Claim:
A rotary damper comprising a fluid chamber which is formed in a casing and into which viscous fluid is charged, a vane which is disposed in said fluid chamber, a fluid passage formed in said vane or in a partition wall which partitions said fluid chamber, and a valve which automatically varies a flow rate of the viscous fluid passing through said fluid passage in correspondence with variation in load, said valve comprises a leaf spring including a to-be supported portion and a flow rate-adjusting portion, the to-be supported portion is supported by the vane or the partition wall, wherein the flow rate-adjusting portion is provided so as not to close the fluid passage when no load is charged and a pressure-receiving surface comprising two or more inclined surfaces having different inclining angles is formed at its one surface of the flow rate-adjusting portion, the flow passage is deformed toward a direction to close the fluid passage to adjust the flow rate of the viscous fluid which passes through the fluid passage by which the pressure-receiving surface receives a pressure of the viscous fluid.