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. 19, 2002
Filed:
Jun. 01, 2000
Kevin D. Struthers, Coatesville, PA (US);
Little Giant Pump Company, Oklahoma City, OK (US);
Abstract
A variable-speed submersible pump has a centrifugal pump, with a grinder for entrained solids at the intake, driven by a variable-speed 3-phase AC motor. A microcontroller controls the pump output on the basis of sensor data and/or inputs from an external controller, and also monitors the operation of the pump unit and emits alarms and statistical reports as appropriate. If the pump is clogged, the controller attempts to free it, firstly by reducing the pump speed and increasing the torque, secondly by jogging the pump backwards, and thirdly by running the pump briefly at maximum speed. Before pumping starts, and at intervals when the tank in which the pump is submerged is not full enough to be worth emptying, the pump is run backwards. That serves to agitate the tank, re-suspend any solids content that may tend to settle out in the tank, and thus improve pumping of the solids with the liquid. When the pump is pumping normally, it starts at a preset speed, and the pump speed may be increased in steps until a desired rate of pumping is achieved or until the maximum speed of the pump is reached.