Impact drilling tool having a shuttle valve
US4054180A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 9, 1976 |
| Grant date | Oct 18, 1977 |
| Priority date | — |
| Expiry date | Feb 9, 1996 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B4/14
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An impact drilling tool for rotary drilling which includes a reciprocating hammer inside a casing for striking the top of an anvil. A drilling bit is connected to the opposite end of the anvil for cutting into the earth's formations. The casing is connected in a string of drilling pipe through which a high pressure fluid flows for operating the hammer and removing cuttings. A feeder means extends through the hammer for alternately directing the high pressure fluid above and below the hammer which high pressure fluid causes the reciprocating motion of the hammer. A shuttle valve located around the feeder maintains communication of the high pressure fluid above the hammer for increased effective stroke to insure a harder driving action of the hammer against the anvil. Also the shuttle valve insures a more complete exhaust above the hammer which reduces the force needed to raise the hammer. In alternative embodiments, the shuttle may control only one of the exhaust or pressurization functions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.