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. 14, 2000
Filed:
Mar. 02, 1998
Peter Bleim, Vienna, AT;
Ewald Frasl, Biedermannsdorf, AT;
Erich Klein, Himberg, AT;
Ernst Ruberl, Guntramsdorf, AT;
U.S. Philips Corporation, New York, NY (US);
Abstract
In an electroacoustic transducer (1) having a diaphragm (17) and a voice coil (16) connected to the diaphragm (17) in the area of the rear volume (HV) and cooperating with a magnet system (9), and including a substantially annular closing member (30) for closing the rear volume (HV), the closing member (30) has an annular body (38) and a ring projection (39), which projects obliquely from the annular body (38) along its entire circumference and is movable against spring action, at least one passage (34, 35, 36, 37) of the closing member (30), this passage having been provided in order to realize an acoustic friction between the rear volume (HV) and the acoustic free space surrounding the transducer (1), terminating in the annular contact surface (32) of the annular body (38), this annular contact surface extending transversely to the transducer axis (2).