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:
Nov. 14, 1989
Filed:
Jul. 20, 1987
Linden Bland, Calgary, CA;
Clifford J Anderson, Sherwood Park, CA;
Murphy Oil Company Limited, Calgary, CA;
Abstract
A downhole pump is actuated by a reciprocating unit comprising a tubular rod string, a valve assembly, and a tubular plunger rod. A flow passage extends through the reciprocating unit when the valve assembly is in an 'open' position, whereby liquid may be injected into the pump barrel chamber to ensure the presence of incompressible fluid in the chamber from the beginning of the up stroke, to thereby reduce or eliminate gas locking of the pump. The valve assembly, which moves together with the reciprocating unit of which it is part, is adapted to interact with a stop member on the stationary pump barrel, to initiate opening of the valve as the rod string approaches the bottom of its stroke. The valve assembly is further adapted to automatically close when lifted away from the stop shortly after the beginning of the up stroke. The valve thus remains open only during the bottoming out phase of the stroke, when only limited travel of the reciprocating unit occurs. The valve assembly is adapted to accommodate this limited travel while remaining open.