Limit switch tripping mechanism for lifting jacks
US4358087A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 6, 1980 |
| Grant date | Nov 9, 1982 |
| Priority date | — |
| Expiry date | Nov 6, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66F3/44
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lifting jack has its upward and downward traveling distance controlled by means of a limit switch. The lifting jack has a base, an upright outer member rigidly connected to the base and an upright inner member movable coaxially within the outer member. An up stop and an adjustable down stop are rigidly attached to and move with the inner member. An adjustable mount is mounted in a fixed position on the outer member, and the limit switch is mounted in fixed position on the mount. A guide shoe assembly is pivotally connected to the mount and is oriented generally perpendicular to the direction of travel of the inner member. A stop engaging member at one end of the guide is positioned to engage the up stop and the down stop, and an arm guiding portion at the opposite end engages and guides an actuating arm of the limit switch. In operation, the guide (and therefore the actuating arm of the limit switch) is biased by garter springs which hold it in a normal position riding on the inner member which is generally perpendicular to the direction of travel of the inner member of the jack. When the stop engaging member engages the down stop, the stop engaging member moves downward and the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.