Patent · US Expired

Device for steering a drilling tool and/or drill string

US4947944A · kind A · utility

70Cited by
12References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 15, 1989
Grant dateAug 14, 1990
Priority date
Expiry dateFeb 15, 2009

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE21B17/1014
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

An outer tube (26) provided with rolling bearings (28) is rotatably mounted on an inner tube (10) which can be connected to a drilling tool or a pipe string. Radially mobile guiding rails are arranged in longitudinal channel-like recesses on the outer surface of the outer tube (26). Belleville springs lodged in spring housings (36) arranged in recesses in the guide rails (35) press against the outer tube (26) and force the guide rails (35) radially outward. The guide rails (35) help prevent rotation of the outer tube, enable it to slide longitudinally in the bore, and guide the inner tube (10) mounted in the outer tube (26) and the drilling tool or pipe string attached to the inner tube (10).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.