Pneumatically operated ram borer
US4295533A · kind A · utility
Inventor
Key dates
| Filing date | Mar 13, 1980 |
| Grant date | Oct 20, 1981 |
| Priority date | — |
| Expiry date | Mar 13, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B4/145
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A self-driven pneumatically operated ram borer for boring holes in the ground includes a casing containing a percussion piston and a control sleeve for controlling the supply of compressed air through a hose to cause the piston to reciprocate, is provided with a control tube which is rotatable to vary the porting of the borer to cause it to move either forwards or rearwards. The tube is rotated into either a forward position or a reverse position by means of a flexible shaft which extends from the casing within the hose. By enclosing the shaft within the hose, the shaft is protected and is not subject to friction against the wall of the hole bored by the borer or to jamming if the hole collapses. The borer can thus easily be controlled even when it has passed through a very long bore hole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.