Closed loop hydraulic drill feed system
US4953639A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1989 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | Sep 8, 2009 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B19/086
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A closed loop hydraulic system for use in a rotary drilling apparatus includes an extendible-retractable feed cylinder and a valve for biasing the feed cylinder. A variable, reversible displacement pump is provided for pumping fluid from either of the first and second pump ports, including pumping fluid to the feed cylinder. A reservoir retains a supply of fluid for the system. A check valve is provided for supplying additional fluid to the pump in response to the feed cylinder being extended. An overcenter valve is connected to each of the first and second ports for controlling flow from the system in response to pressures received from the first and second ports when the feed cylinder is extended and retracted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.