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:
Mar. 24, 1981
Filed:
Aug. 24, 1979
Chester M Bordelon, Shreveport, LA (US);
Richard C Sherwood, New Providence, NJ (US);
Bell Telephone Laboratories, Incorporated, New York, NY (US);
Bell Telephone Laboratories Incorporated, Murray Hill, NJ (US);
Abstract
Electroacoustic devices are disclosed which comprise a permanent magnet and a magnetically permeable component. The permanent magnet is made of an Fe-Cr-Co alloy comprising 20-40 weight percent Cr and 3-30 weight percent Co; the permeable component is made of an Fe-Al alloy comprising 1.5-18 weight percent Al. In addition to a magnetic circuit, disclosed devices comprise means such as, e.g., an induction coil for inducing a variable magnetic field in the magnetic circuit. Also, devices comprise means for utilizing energy output in response to the magnetic field. Energy output may typically be in the form of an acoustical signal having desirably flat frequency response. Due to their low cost, disclosed devices are particularly suitable for use in telephone receivers and other mass produced articles.