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, 1992
Filed:
Mar. 26, 1990
Karsten A Laing, Chula Vista, CA (US);
Nikolaus J Laing, Chula Vista, CA (US);
Other;
Abstract
In a plumbing installation wherein hot water is piped from a water heater or reservoir to a plurality of taps by a distribution conduit, an improved recirculation circuit of limited power consumption to continually pump small amounts of hot water from said conduit back into said reservoir which comprises a low power radial pump unprotected by a check valve against backflow, but having a rotary impeller with linear radial vanes leading to an annular output channel larger than necessary for maximum pumping throughput. The oversized annular channel and linear vanes limit the impact of any backflow upon the impeller and prevents its operating as a tubine as the pump is subjected to back pressure when a large amount of water is being drawn through the taps.