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:
Jun. 08, 1976
Filed:
Apr. 24, 1975
Soren E Edstrom, Quincy, IL (US);
Richard L Ertel, Quincy, IL (US);
Robert A Litteken, Quincy, IL (US);
Gardner-Denver Company, Dallas, TX (US);
Abstract
A positive displacement rotary compressor is in circuit with a closable chamber disposed upstream of the compressor gas inlet and including a conduit operable to be placed in communication with the compressor discharge conduit. A control circuit is operable to sense compressor discharge pressure and at a predetermined pressure condition sequentially operate valves to shut off compressor inlet flow thereby evacuating the chamber and then placing the compressor discharge port in communication with the chamber. The compressor thereby runs unloaded or at idle at a greatly reduced inlet and discharge pressure. The operation of unloading the compressor may be controlled by sensing the chamber vacuum or by the use of time delay devices.