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:
Oct. 11, 1983
Filed:
Jul. 14, 1977
Robert Bosch GmbH, Stuttgart, DE;
Abstract
An ultrasonic transmitter is disposed on one wall inside the air induction tube of an internal combustion engine and an ultrasonic receiver is disposed on the opposite wall, downstream of the transmitter. A second transmitter-receiver pair is similarly located, but with the positions of transmitter and receiver reversed. Thus, the signals from one transmitter travel generally with the air flow, whereas the signals from the second transmitter travel generally against the air flow. Since the travel time of the signals depends on the velocity of the flowing air, the frequencies of signals from the two receivers are different and this difference is used to determine the air velocity and, hence, the air flow rate.