| 摘要 |
A coil spring slip clutch adapted for use in a roll film camera for advancing a film strip within the camera. The clutch comprises a rotatably mounted cylindrical drive shaft having a smooth surface portion around which the coils of a coil spring are tightly wrapped. One end of the coil spring is bent outwardly so as to drivingly engage a film advancing mechanism when the shaft is rotated. The contacting surfaces of the coil spring and drive shaft are selected from materials which remain in frictional engagement sufficient to cause the coil spring to drive the film advancing mechanism until the retarding force exerted by such mechanism exceeds a critical frictional force characteristic of one of the materials, at which time the coil spring slips relative to the drive shaft.
|
