Hydraulic control systems for use with mining apparatus
US4046060A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1975 |
| Grant date | Sep 6, 1977 |
| Priority date | — |
| Expiry date | Aug 4, 1995 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21C35/14
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic control system for use with double-acting shifting rams in a mine working. The system has a pump for supplying pressure fluid and main and return feed lines or conduits connected to the pump and laid along the working. An adjustable pressure-regulating device or devices serves to provide fluid at variable pressure in a further feed line or conduit. Each ram has its working chambers connected to a control device which is in turn connected to the main and further feed lines or conduits and to the return line or conduit. The devices can each be set to various positions to operate the rams in order to extend one of the rams its associated device is set to connect the working chamber used for extension (having the larger piston working surface area) to the further feed line or conduit, and to connect the other working chamber used for retraction (having the smaller piston working surface area) to the to the main feed line or conduit. With the aid of the pressure-regulating device or devices the force of the ram can then be controlled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.