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. 06, 2012
Filed:
Nov. 02, 2006
Guy Lemarquand, Le Mans, FR;
Bernard Richoux, Montoire, FR;
Valérie Lemarquand, Le Mans, FR;
Universite du Maine, Le Mans, FR;
Other;
Abstract
The invention relates to an electrodynamic transducer () with a dome type diaphragm (), comprising an electrodynamic motor with a coil () borne by a mandrel () integral with the diaphragm suspended to a yoke (), the coil being placed in an air gap of a vertical free space in which it can move and which is defined, toward the center, by an internal magnetic construction (), and toward the periphery, by an external magnetic construction (), wherein the suspension comprises neither peripheral suspension nor internal suspension, the transducer comprises at least two magnetic field confinement means () in the air gap in order to form by mean of a ferromagnetic liquid at least two ferrofluidic seals () stepped in the air gap, fulfilling at least the guidance of the coil and the pneumatic tightness between the front and rear faces of the diaphragm, at least one of the ferrofluidic seals being continuous. Application to loudspeakers.