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:
Jul. 31, 1979
Filed:
Jan. 03, 1978
Applicant:
Inventors:
Paul A Charles, Rockford, IL (US);
Frederic D Williams, Mississauga, CA;
Assignee:
Royal Flush (1979) Inc., Hamilton, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E03D / ; B01D / ;
U.S. Cl.
CPC ...
4318 ; 4317 ; 4420 ; 210411 ; 2104 / ; 2104971 ; 417395 ; 417540 ;
Abstract
A back-washable filtering element, especially for use with pumps, and more particularly for use with pumps that handle liquids with solid material entrained therein, consists of a helical coil spring disposed in a flow path for the liquid to be filtered. A movable element in the flow path is mechanically connected to the spring and compresses it axially under the effect of the back washing liquid to automatically reduce the flow capacity. The resultant 'shrugging' of the spring also permits it to clear itself of filtered material to facilitate the back-washing.