Pressure relief valve for hydraulic mine supporting elements
US4111227A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1976 |
| Grant date | Sep 5, 1978 |
| Priority date | — |
| Expiry date | Sep 1, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7781
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A pressure relief valve for hydraulic mine supporting elements, particularly mine props, has a valve member loaded in its closing direction by a spring, a piston is connected to the valve member end sealingly sliding within a cylinder of the valve housing and arranged to be acted upon in closing direction by the pressure prevailing within the space before the seat of the valve member. The valve member has a neck portion of reduced diameter between the valve seat and the piston and the annular cross section, being acted upon in closing direction, between the neck portion and the circumference of the piston is smaller than the annular cross section, being acted upon in opening direction, between the neck portion and the valve seat.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.