Anti-backup mechanism for preventing reverse rotation of film winder in camera
US5576790A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 1996 |
| Grant date | Nov 19, 1996 |
| Priority date | — |
| Expiry date | Feb 7, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B1/04
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A camera comprises manually rotatable film winding means, and a uni-directional clutch coupled to the film winding means to permit film winding rotation of the film winding means and to prevent reverse rotation of the film winding means. The film winding means includes a rotatable winder wheel having a toothed periphery. The uni-directional clutch includes a rotatable idler wheel having a toothed periphery engaging the toothed periphery of the winding wheel and provided with less teeth than the toothed periphery of the winding wheel, and a coil spring coiled tightly about a shank of the idler wheel and having an end portion secured with respect to the shank. The coil spring tightens on the shank to prevent the idler wheel and the winding wheel from being engagingly rotated when reverse rotation of the film winding means is attempted and relaxes on the shank to permit the idler wheel and the winding wheel to be engagingly rotated when film winding rotation of the film winding means is initiated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.