A detent mechanism

摘要

A detent mechanism that acts between two components (11,16) that rotate with respect to one another to control rotation from a first set position to a second set position. The detent mechanism comprises at least one rotating cam (23) positioned between adjacent surfaces of two components (11,16). The cam (23) is journalled for rotation on one of the components (11) about an axis that is substantially transverse to the axis of rotation between the two components (11,16). The operating surface (25) of the cam (23) comprises at least one cam lobe that is caused to rotate as the two components (11,16) rotate. The cam (23) acts to separate the two components (11,16). Spring (17) acts to urge the adjacent surfaces together so that a predetermined torque is required to cause relative rotation between the components (11,16). The advantage of the detent mechanism (10) is that sufficient resistance to rotation can be obtained with a relatively light spring (17) due to the high rate of lift provided by the cam (23).