Spool for web-shaped film
US4852821A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 1988 |
| Grant date | Aug 1, 1989 |
| Priority date | — |
| Expiry date | Aug 29, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/261
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A spool for holding photographic film, consisting of a core member provided with flanges between which flexible film may be wound and an elongated slot into which the end portion of a film strip may be entered and fastened. Adjacent the flanges are raised shoulders extending about the circumference of the core and above the core surface. The shoulders each gradually increase in thickness in the film-winding direction and terminate in a stepped portion corresponding to the thickness of the film. In a preferred embodiment, shoulder portions accommodate the edge portion of a full-width film, have an initial height above the surface level of said spool, and then rise gradually to an additional height approximately equal to the thickness of the film. When the full-width portion of the film is juxtaposed the spool flanges, said shoulders provide the film with a substantially level transition surface for each convolution of the full-width film, thereby avoiding imperfections on the spool-core surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.