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. 01, 1985
Filed:
May. 27, 1982
Applicant:
Inventor:
Alex Blum, Unterentfelden, CH;
Assignee:
Sprecher & Schuh AG, Aarau, CH;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01F / ;
U.S. Cl.
CPC ...
335245 ; 335249 ; 335261 ;
Abstract
The transducer comprises an armature and a core. Both pieces are E-shaped, and their geometrical dimensions are chosen so that when their central legs come into mutual contact, air gaps still exist between both pairs of outer legs where these face each other. A coil bobbin is fixed to the core and forms a straight guide for the central leg of the armature. The frontal surfaces of the outer legs are chamfered so that the limiting surfaces of the air gaps are inclined with respect to the travel direction of the armature. In order to minimize the hum, a short-circuit ring is embedded into the central leg of the core.