US 11,838,736 B2
Electromagnetic actuator for a speaker or a sound transducer with a multimetal layer connection between the voice coil and the magnet system
Gustav Otto, Vienna (AT); Markus Trampert, Vienna (AT); Stefan Gebhardt, Vienna (AT); Andreas Hintennach, Vienna (AT); Manuel Mefleh, Vienna (AT); and Ernst Tomas, Strasshof an der Nordbahn (AT)
Assigned to Sound Solutions International Co., Ltd., Beijing (CN)
Filed by Sound Solutions International Co., Ltd., Beijing (CN)
Filed on May 19, 2021, as Appl. No. 17/325,032.
Claims priority of application No. A 50441/2020 (AT), filed on May 20, 2020.
Prior Publication US 2021/0368276 A1, Nov. 25, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. H04R 9/06 (2006.01); H04R 9/02 (2006.01); H04R 9/04 (2006.01); H04R 7/16 (2006.01); H04R 7/12 (2006.01); H04R 1/02 (2006.01)
CPC H04R 9/06 (2013.01) [H04R 1/028 (2013.01); H04R 7/12 (2013.01); H04R 7/16 (2013.01); H04R 9/025 (2013.01); H04R 9/045 (2013.01); H04R 9/046 (2013.01); H04R 2499/15 (2013.01)] 30 Claims
OG exemplary drawing
 
1. Electrodynamic actuator, which is designed to be connected to a backside of a plate like structure or membrane opposite to a sound emanating surface of the plate like structure or the membrane and which comprises
at least one voice coil, which has an electrical conductor in the shape of loops running around a coil axis in a loop section, and
a magnet system being designed to generate a magnetic field transverse to the conductor in the loop section and
an arm arrangement of a plurality of arms connecting the at least one voice coil and
a) the magnet system and allowing a relative movement between the voice coil and said magnet system in an excursion direction parallel to the coil axis or
b) a movable part of the magnet system and allowing a relative movement between the voice coil and said movable part of the magnet system in an excursion direction parallel to the coil axis,
wherein
the arms are made of a metal core, which at least partly is coated with a coating structure having at least one coating metal layer consisting of a different material than the metal core, and
wherein the bending stress within the metal core is below its fatigue strength, whereas the bending stress within the at least one coating metal layer is above its fatigue strength, or the bending stress within the metal core is below its ultimate tensile strength, whereas the bending stress within the at least one coating metal layer is above its bending ultimate tensile strength when the excursion of the voice coil relative to the magnet system or its movable part in a direction parallel to the coil axis reaches its nominal maximum of the electrodynamic actuator or is above 0.4 mm with respect to the idle position of the voice coil.