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:
Aug. 13, 1985
Filed:
Nov. 17, 1983
Francois Nadeau, St-Bruno, Quebec, CA;
Jean F Bussiere, St-Bruno, Quebec, CA;
Ghislain Vaudreuil, Boucherville, Quebec, CA;
Other;
Abstract
An acoustic crack detection method and device in which an impact is produced between an actually tested metal piece and an anvil. This impact generates an acoustic wave formed of a plurality of components, one of these wave components being produced by vibrations of the metal piece and having a frequency indicating a cracked or uncracked state of this piece. A microphone senses the acoustic wave generated by the impact and a measuring circuit receives the signal from the microphone for measuring the energy, within a predetermined time gate and within a predetermined frequency bandwidth, of the wave component of interest. The measured energy is compared with a reference level in order to determine if the actually tested metal piece is cracked or not. Of course, the anvil is designed so that its vibrations produced by the impact generate no wave component at a frequency included within the predetermined frequency bandwidth, whereby the crack detection is not disturbed by any acoustic wave component generated by the anvil. The detecting device may be used in an apparatus for sorting cracked and uncracked metal pieces.