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. 26, 1986
Filed:
Dec. 20, 1984
Klaas Zwart, Dyce, Aberdeen, GB;
Other;
Abstract
An upstroke wireline jar having a hammer 12 at the bottom end of an operating rod 3 which is axially slidable in a casing 2 having an anvil 13 at its upper end. This casing also includes a releasable coupling means which is biased downwards by a spring 5 to a rest position, said coupling means comprising a sleeve 4 which receives the rod 3 into its upper end and a plurality of arcuate segments 9 which are contained in apertures in the sleeve and engage in a circumferential groove 10 in the rod. Circumferential recesses 11 and 17 in the interior wall of the casing 2 are adapted to partially receive the segments when the sleeve is in appropriate registration therewith thereby facilitating disconnection and subsequent re-engagement of the operating rod with the sleeve. The spring 5 is mounted below the hammer so as to allow free travel of the latter along a substantial portion of the casing. The spring is provided with an upper abutment 6 mounted on a rod 7 the axial position of which is adjustable from outside the jar. At its bottom end the spring 5 abuts a flanged bush 15 which depends from the sleeve 4. A second spring 6 assists in biasing the sleeve to its rest position.