Ground-drilling device
US9328560B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 8, 2011 |
| Grant date | May 3, 2016 |
| Priority date | — |
| Expiry date | Mar 9, 2033 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/03
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A ground-drilling device includes a basic body and a drill head movably mounted in relation thereto in the longitudinally axial direction, wherein a free space, which is variable in its size owing to the movable mounting, is formed between the drill head and the basic body, and a sealing element for sealing the free space with respect to the environment, wherein the sealing element is designed as a valve element which opens when an overpressure is present inside the clearance, in order to produce a pressure compensation, and which is closed when a negative pressure is present inside the clearance, in order to prevent a pressure compensation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.