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. 01, 1995
Filed:
Dec. 30, 1992
Thomas E Smith, Madison, NJ (US);
Gregory W Terpay, Whippany, NJ (US);
George G Zipfel, Jr, Summit, NJ (US);
AT&T Corp., Murray Hill, NJ (US);
Abstract
Disclosed is an electrodynamic moving coil actuator comprising one or more separate coils contained in interior spaces of a reactance mass. The coils are oriented in closely spaced parallel zones within the interior spaces. The spaces are formed and positioned to be outside of the static magnetic flux lines of the reactance mass. The static flux thus is substantially de-coupled from the dynamic magnetic field of the coil. Magnetic flux choke points are avoided, but at the same time, high volumetric efficiency is achieved. Each coil is attached to supports along its two long outer edges. The supports are connected to each other at their extremities by top and bottom plates which are connected by slide bars that also serve as tie rods. The reactance mass is mounted on the slide bars. The design is adapted to low frequency, high force applications such as active noise control automotive mufflers.