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:
Apr. 19, 1994
Filed:
Jun. 30, 1992
Randall J Vavra, Orange, CA (US);
Michael J Doyle, Villa Park, CA (US);
Kim N Vu, Yorba Linda, CA (US);
Unit Instruments, Inc., Yorba Linda, CA (US);
Abstract
A liquid flow controller for metering a flow of liquid has an inlet to receive the liquid. The inlet feeds the liquid to a high resistance liquid flow path across which a pressure drop arises. A pressure sensor measures the liquid flow induced pressure drop and generates pressure drop signal which is fed to an electronic circuit. A temperature sensor is connected to the high resistance liquid flow path and generates a temperature signal which is also fed to the electronic circuit. The circuit energizes a viscosity-normalized liquid flow signal, which is compared to a set point signal to generate an error signal. A valve connected downstream of the high resistance liquid flow path to control the flow of liquid is driven by the error signal and thereby controls the flow of liquid.