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:
Jul. 30, 1985
Filed:
Aug. 31, 1981
Gary M Crase, Cypress, CA (US);
Other;
Abstract
A releasable coupling or safety sub for a drill string including an inner tubular member piloted within an outer tubular member, the inner member including expansible, segmental lock members shiftable laterally of the tubular members into locking engagement with a transverse shoulder on the outer member, a retaining member holding the lock members outwardly in engagement with the shoulder, release of the retainer member from the lock members enabling the latter to move laterally inwardly to a position released from the shoulder, permitting the tubular members to be separated from one another. The coupling includes a device for imposing an axial preload on the inner and outer members to place the outer member in compression and the inner member in tension to provide a rigid structure.