Patent · US Expired

Double acting hydraulic mechanism

US4361195A · kind A · utility

37Cited by
7References
35Claims
0Family size

Inventor

Key dates

Filing dateDec 8, 1980
Grant dateNov 30, 1982
Priority date
Expiry dateDec 8, 2000

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE21B31/113
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A double acting hydraulic drilling mechanism, i.e. drilling jar, is disclosed for use in a tubular drilling string for applying upward or downward jarring forces for dislodging a "fish" from a well. The jar is adapted to be run into a well on a drill string and connected to a fishing tool in the well bore. This jar comprises outer and inner housing members positioned in telescoping relation for longitudinal movement of one relative to the other and having a hammer member on one and an anvil member on the other. The housing members enclose a chamber adapted to contain a fluid for controlling application of jarring forces. A pair of pistons are positioned in spaced relation for movement of each relative to the other in the hydraulic fluid chamber. The pistons are arranged so that movement of one housing relative to the other in one direction will move the first piston toward the second and movement in the opposite direction will move the second piston toward the first. The chamber between the pistons has an outlet controlled by a suitable valve member. Valve actuating means are provided which are operated upon predetermined relative movement of the housing members in either direction…

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