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. 08, 1994
Filed:
Jul. 21, 1993
Applicant:
Inventors:
G Wayne Westerman, Midland, TX (US);
Richard C Montgomery, Midland, TX (US);
Gerald W Pippin, Midland, TX (US);
Assignee:
Automation Associates, Midland, TX (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04B / ;
U.S. Cl.
CPC ...
417 12 ; 417 18 ; 417 4411 ; 417 53 ;
Abstract
A pump-off controller checks for pump-off by examining the relative phase relationship between AC voltage and AC current supplied to an inductive, alternating current, electric motor driving a cyclically operated mechanical system having a walking beam for raising and lowering a subsurface pump by means of a string of sucker rods. When the phase angle between AC voltage supplied to the motor and AC current drawn by the motor exceeds a predetermined value at selected points or regions of the pumping stroke, the pumping system is shut down for a predetermined time.