Film cassette
US4991786A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 1990 |
| Grant date | Feb 12, 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 is rotatable inside a cassette shell in an unwinding direction to thrust a leader section of a filmstrip coiled about the spool from within a light-tight film passageway to the exterior of the shell and in a winding direction to return the leader to the interior of the shell. A unidirectional arresting device is movable into engagement with the spool to prevent rotation of the spool in only the winding direction. The filmstrip includes an inclined edge for moving the arresting device out of engagement with the spool responsive to thrusting the leader substantially to the exterior of the shell, to allow the spool to be rotated in the winding direction in order to return the leader to the interior of the shell, and for permitting the arresting device to move into engagement with the spool responsive to return of the leader to within the passageway, to prevent the spool from being rotated further in the winding direction to thereby retain the leader in the passageway.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.