Automatic extension control system for jacking device
US4142710A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 28, 1977 |
| Grant date | Mar 6, 1979 |
| Priority date | — |
| Expiry date | Nov 28, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66C23/80
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
Extension control system for jacking device for traveling loading machines such as truck crane for jacking up during the loading operation, keeping the machine in the horizontal position, which comprises at least four oil hydraulic jacks for supporting the traveling loading machine, means for supplying pressure oil to the hydraulic cylinder of each jack, means for sensing level of the traveling loading machine, and a stroke-end sensing device provided for each jack operative to generate a signal when the jack extends to the stroke-end. The system is so arranged that the conduit for supplying the pressure oil to the cylinder for the jack in higher side is shut-off, when the machine tilts and the means for sensing the lift of the machine is actuated, and further the extension of all jacks is stopped, when at least one of the stroke-end sensing device is actuated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.