Film thrusting cassette
US5046679A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 1990 |
| Grant date | Sep 10, 1991 |
| Priority date | — |
| Expiry date | Jan 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2217/266
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a film cassette, a film spool comprises a spool core supported for rotation in an unwinding direction to thrust a leader section of a filmstrip coiled about the spool core from the cassette and in a winding direction to return the leader to the cassette, and a pair of flanges positioned along the spool core to overlie opposite sides of the film roll. The flanges have respective central openings through which the spool core axially extends to normally permit each of the flanges to be independently rotated relative to the spool core in the unwinding and winding directions. According to the invention, the spool core includes a core piece connected to a remaining portion of the spool core for limited movement within the central opening of one of the flanges, away from the remaining portion, to engage the flange to rotate the flange in unity with the spool core when the spool core is rotated in the unwinding direction, to improve the ability of the film spool to thrust the leader from the cassette, and toward the remaining portion, to disengage the flange to permit the flange to be independently rotated when the spool core is rotated in the winding direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.