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:
May. 19, 1981
Filed:
Aug. 13, 1979
Fount E McKee, Houston, TX (US);
Delta-X Corporation, Houston, TX (US);
Abstract
A hydraulic pumping unit for vertically actuating a downhole pump including first and second hydraulic piston and cylinder assemblies. The first assembly is connected to the downhole pump and the second assembly is connected to a counterweight. A hydraulic line is connected between the first and second assemblies so that the counterweight counterbalances the downhole pumping equipment. A hydraulic pump is connected to the first and second assemblies through switching means for alternately supplying hydraulic fluid to and from the first and second assemblies. A check valve is provided between the hydraulic pump and the hydraulic line for replenishing the assemblies with fluid. A safety valve is connected between the first assembly and the hydraulic line for preventing the first assembly dropping in the event of a hydraulic line failure. A return valve in parallel with an orifice closes in the event the hydraulic pump stops for preventing free fall of the first assembly. A pressure switch connected to the second assembly insures that hydraulic fluid is supplied into the first cylinder to prevent actuation of the check filling valve on each stroke.