Limit switch weight apparatus for crane hoist drives
US5405027A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 14, 1994 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | Jan 14, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66D1/56
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
Disclosed is a crane hoist system having a hoist drum, a drum drive motor and control and power circuit limit switches. The improvement involves a first trip bar coupled to the power circuit limit switch and a second trip bar coupled to the control circuit limit switch. The bars are-vertically aligned and both are pivot mounted at their corresponding ends. The second trip bar is mounted for movement independently of the first trip bar. If the control circuit limit switch fails to function as the second bar is moved a suitable distance upward, such bar contacts and lifts the first bar which, in turn, trips the power limit switch. In one embodiment, both bars are straight and elongate and in another, the second bar is "U" shaped.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.