Photographic film cassette
US5265820A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 1991 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Nov 26, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S242/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A cassette shell consists of two shell halves, and rotatably contains a spool core on which a photographic film is wound. A pair of spool flanges are loosely fitted on the spool core. Rotation of the spool core causes a film leader to advance through a film passage slit. A melting point of resin for molding the spool flanges is different from that of resin for molding the cassette shell for the purpose of avoiding undesired ultrasonic welding on their contact surfaces when joining the shell halves. The spool flanges are molded from material including polyolefin resin having a high density and a high molecular weight in order to reduce friction against the cassette shell and the photographic film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.