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:
Sep. 01, 1981
Filed:
Oct. 31, 1979
Thomas R Standish, Houston, TX (US);
Delta-X Corporation, Houston, TX (US);
Abstract
A control circuit for turning off the electrical power to the drive motor, which reciprocates a polished rod of a pump, when the pump has exhausted the supply of liquid in the well. Simultaneously measuring the polished rod load and rod position and turning off the power when the load is greater than or equal to a preset load and the position is equal to a preset position on the downstroke of the well. A first comparator measures the polished rod load relative to a preset load, and a second comparator measures the polished rod position relative to a preset point so that the power is shut off when the load is greater than or equal to the preset load and the position is equal to the preset point on the downstroke. A set of digital latches act to insure that the load is greater than the preset load for two consecutive strokes before the power is shut off. Measuring when the polished rod load is less than a preset load and the polished rod position is equal to a preset point on the upstroke and turning off power to the well and signalling that an abnormal condition exists at the well. Connections are provided for an external plotter so that a plot of load versus position can be plotted to give a visual representation of the well activity.