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:
Jan. 31, 1984
Filed:
Nov. 30, 1981
Kirk B Peloza, Glen Ellyn, IL (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A low pressure drop hot film mass air flowmeter (10) for an automotive engine is disclosed. The flowmeter includes a main air flow passage (20), a fixed contoured flow nozzle (22) disposed in the main air flow passage to establish a localized pressure differential thereacross and, a closed circuitous recirculation path (40) disposed adjacent the main air flow passage and in fluid communication therewith through an inlet port (42) disposed upstream of the flow nozzle and an outlet port (44) disposed downstream from the flow nozzle. Pressure differential at the ports establishes a substantially laminar control flow therebetween within the recirculation path which, in turn, by viscous action, establishes a recirculation flow (67) within the recirculation path. A constant temperature thermal anemometer (54) includes a hot film probe (56) and a temperature compensating probe (58) positioned to sense the recirculating air within the recirculation path. In the preferred embodiment of the invention, a second contoured flow nozzle (96) is disposed within the recirculation path to facilitate flow sensing therein. The anemometer generates an output signal representative of total mass air flow through the flowmeter.