Valve for use in controlling the functions of mine roof supports
US4799510A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 30, 1987 |
| Grant date | Jan 24, 1989 |
| Priority date | — |
| Expiry date | Mar 30, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/87225
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A valve assembly is provided for use in controlling a plurality of fluid operated functions. The assembly comprises a plurality of valve members 14, each movable independently to carry out a fluid flow control function for example, a function of a hydraulic mine roof support. There are means 39 for supplying hydraulic fluid to all the valve members 14 thus tending to move all the valve members, but there is also an interposer device 18 positionable in the path of at least one of the valve members to prevent the said one of the valve members from carrying out its fluid control function, thus enabling the valve members to be selectively operable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.