The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 29, 1978
Filed:
Mar. 28, 1977
Derrel D Webb, Houston, TX (US);
Edwin A Anderson, Houston, TX (US);
Other;
Abstract
A double acting jar includes inner and outer telescopically arranged tubular parts movable longitudinally, but nonrotatable relative to each other. Cooperating means on the inner and outer telescopically arranged tubular parts deliver an upward jar to a stuck drill string upon relative longitudinal movement of the inner and outer telescopically arranged tubular parts in one direction and deliver a downward jar to a stuck drill string upon relative longitudinal movement of the inner and outer telescopically arranged tubular parts in the other direction. The cooperating means is constructed and arranged to be disengaged and maintained in an inoperative relationship when the drill string is in tension and compression during rotary drilling operations. When the jar is effected by a hydraulic jarring arrangement, fluid meter means incorporates a temperature responsive, compensating means to maintain substantially uniform flow rates through the metering means at varying temperature conditions. An overloading valving arrangement prevents overloading of the hydraulic jar and enables it to unload prior to damage to the jar tool. The jar is constructed and arranged so that the magnitude of the upward or downward impact may be readily and substantially automatically varied while the tool is in the well bore.