Brake mechanism for motor driven projection screen
US4059339A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 8, 1976 |
| Grant date | Nov 22, 1977 |
| Priority date | — |
| Expiry date | Jan 8, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B21/58
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A brake mechanism for an electric motor used to drive a projection screen apparatus. The brake mechanism includes a first brake surface fixed to an exterior brake support about an end of the motor shaft projecting from the housing, a second brake surface adjustable on the shaft end and confronting the first brake surface, and a spring for normally urging the brake surfaces into engagement to prevent rotation of the shaft, and brake surfaces being urged apart and the action of the spring counteracted when the motor is operated as the rotor of the motor, which is carried by the shaft, aligns itself with the magnetic field generated by the stator of the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.