US Patent 7137732 Portable timepiece

A portable timepiece has a bezel rotatably disposed on a case body, and an elastically deformable gasket interposed between the case body and the bezel in an elastically deformed state to exert a frictional force on the case body and the bezel sufficient to maintain the bezel in a stationary rotational position though permitting the bezel to be manually rotated to any desired position by overcoming the frictional force. One or more lock members are movably disposed on the bezel and contact a slip-preventing part provided on the case body. A manually rotatable holding ring engages with the lock members and is rotatable in one direction to increase the contact pressure between the lock members and the slip-preventing part to thereby prevent unintended rotation of the bezel, and is rotatable in the other direction to decrease the contact pressure to thereby permit manual rotation of the bezel by overcoming the frictional force exerted by the elastically deformed gasket. In this manner, inadvertent rotation of the bezel is prevented by structure other than the gasket thereby preventing undue wear of the gasket.