Hoist with proximity limit switches
US6135421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1999 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Oct 29, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66D1/56
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A hoist apparatus comprising a frame, a hoist drum mounted on the frame for rotation about a drum axis, a motor connected to the drum for selectively rotating the drum in opposite wind-up and wind-off directions about the drum axis, a hoist rope wound around the drum such that the rope winds on to and off of the drum in response to rotation of the drum in the wind-up and wind-off directions, respectively, the rope having a maximum wind-up point beyond which it is not desirable to wind a significant amount of rope on to the drum, and a proximity switch mounted on the frame adjacent the drum such that the drum moves relative to the switch, the switch being capable of sensing the presence of the rope without touching the rope, and the switch preventing the motor from rotating the drum in the wind-up direction when the switch senses the presence of the rope on the drum at the maximum wind-up point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.