Film tension absorbing system
US4087165A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1975 |
| Grant date | May 2, 1978 |
| Priority date | — |
| Expiry date | Dec 17, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/44
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A film tension absorbing mechanism is provided on a motion picture projector for absorbing film tension shock in the film strip. The tension absorbing mechanism includes a first system comprising the combination of a pivotally mounted, biased film exit guide roller for absorbing a portion of the tension and a tension absorbing sprocket drive to permit relative movement between the film strip and the sprocket. The tension absorbing sprocket includes a sprocket wheel and a relatively movable sprocket tooth ring rotatably mounted for generally conjoint rotation. The sprocket tooth ring is biased in a direction opposite the rotation of the sprocket wheel so that film tension shock can be absorbed as the sprocket tooth ring rotates relative to the sprocket wheel in a direction against the biasing force. A second system also is provided and includes a bi-directional tension absorbing drive sprocket for absorbing film tension shock in two directions. A sprocket tooth ring is mounted on a sprocket wheel for relative rotation therewith in two directions. A biasing mechanism provides for a different biasing torque to be applied to the tooth ring as it rotates in one direction versus rotation…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.