Bidirectional web medium drive
US4012134A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1975 |
| Grant date | Mar 15, 1977 |
| Priority date | — |
| Expiry date | Dec 12, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/113
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A bidirectional web medium drive for moving a web of material such as a roll of microfilm between two reels consisting of a pair of reversible motors coupled through irreversible drives to corresponding spindles which receive and support each of the film reels. A torque controller is coupled to one of the motors for applying a constant output torque to that motor while a variable speed controller is coupled to the other motor for controlling the output speed of that motor. In one embodiment, a switch is provided so that when the switch is in a first position, the torque controller is connected to one of the motors to apply a constant torque to its spindle so that its associated reel becomes the take-up reel while the speed controller is connected to the other motor so that its reel becomes the supply reel and both motors rotate in the same direction. When the switch is thrown into a second position, the outputs of the torque controller and speed controller are interchanged with respect to the motors, and the polarity of the motors is reversed so that the film moves in the opposite direction and the function of the reels are interchanged. In another embodiment, the switch is elimina…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.