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:
Oct. 11, 1988
Filed:
Nov. 26, 1985
Applicant:
Inventors:
Jorg Schulze-Beckinghausen, Garbsen, DE;
Hans-Christian Bock, Burgdorf, DE;
Assignee:
Weatherford/Lamb, Inc., Houston, TX (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B25B / ;
U.S. Cl.
CPC ...
81 5744 ; 81 5719 ; 137491 ; 251 26 ;
Abstract
A power tong assembly wherein a safety latch mechanism includes a power part equipped with two outlet side connections, one of which is connected to a control part for controlling the opening cross section of the tank side connection. The power part has a control element in the form of a piston-shaped valve body with equal sized surfaces on both end faces subject to the pressure of the working medium and with a bore running in the direction of the valve body movement. This bore has a conical extension of its inlet flow end. This blocks the direct connection of the supply with the return to the tank.