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:
Feb. 27, 1996
Filed:
Oct. 29, 1993
Lawrence C Arvidson, New Brighton, MN (US);
Robert S Horeck, Fridley, MN (US);
Hypro Corporation, St. Paul, MN (US);
Abstract
A fire fighting system introduces a liquid chemical foam concentrate into a water stream. The system may incorporate either or both of a hydraulic motor driven pump under control of a microprocessor-based hydraulic valve driver and an electric motor driven pump under control of a DC motor drive circuit. The DC motor drive circuit is adapted to be connected in electrical communication with the hydraulic valve driver and with a display/controller also incorporating a microprocessor. When operating in the dual mode, when the quantity of chemical foamant that must be added to the water stream to maintain a desired percentage mixture exceeds the capacity of the electric motor driven foam pump, control is transferred, via the hydraulic valve driver, to allow a hydraulic motor to drive a separate foam pump. In this fashion, the electric motor driven foam pump can cover a first range of flow rates from a very low rate to an intermediate rate and the hydraulic system then taking over to extend the range from the intermediate flow rate to a relatively high flow rate.