Safety mechanism for hoisting drums
US4518153A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1984 |
| Grant date | May 21, 1985 |
| Priority date | — |
| Expiry date | Jun 27, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/19688
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
The safety system in a hoist having a motor with a motor shaft, a gear reduction unit, a drum, a safety brake drivingly coupled on an operating element on or close to the drum in which a mechanical out-of-sync detector produces a unidirectional brake-setting output from inputs from the drum and the motor shaft, the unidirectional brake-setting rotational output for setting the brake. In a preferred embodiment, an error correction is made into the detector for obtaining a first unidirectional output during normal operation, and the brake-setting unidirectional rotation is in the opposite direction for setting the brake. One form of detector is a mechanical differential assembly and another form of detector is a set of coaxial shafts that measure differential rotation between the drum and motor input shafts. A unique brake actuator is provided and is easily reset remotely after the brake has been set.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.