US 12,284,507 B2
Force transducers for electroacoustic drivers and loudspeakers containing same
Joseph F. Pinkerton, Austin, TX (US); David A. Badger, Lago Vista, TX (US); James A. Andrews, Austin, TX (US); William Martin Lackowski, Austin, TX (US); and William Neil Everett, Cedar Park, TX (US)
Assigned to Brane Audio, LLC, Austin, TX (US)
Filed by Clean Energy Labs, LLC, Austin, TX (US)
Filed on Feb. 21, 2023, as Appl. No. 18/112,237.
Application 18/112,237 is a continuation of application No. 17/794,567, previously published as PCT/US2020/051633, filed on Sep. 18, 2020.
Claims priority of provisional application 63/048,393, filed on Jul. 6, 2020.
Claims priority of provisional application 63/022,125, filed on May 8, 2020.
Claims priority of provisional application 62/963,833, filed on Jan. 21, 2020.
Prior Publication US 2023/0199401 A1, Jun. 22, 2023
Int. Cl. H04R 9/06 (2006.01); H04R 1/02 (2006.01); H04R 1/28 (2006.01); H04R 3/00 (2006.01); H04R 9/02 (2006.01); H04R 9/04 (2006.01); H04R 11/02 (2006.01); H04R 17/00 (2006.01); H04R 29/00 (2006.01)
CPC H04R 9/06 (2013.01) [H04R 1/025 (2013.01); H04R 1/2803 (2013.01); H04R 3/00 (2013.01); H04R 9/025 (2013.01); H04R 9/041 (2013.01); H04R 9/046 (2013.01); H04R 11/02 (2013.01); H04R 17/00 (2013.01); H04R 29/001 (2013.01); H04R 29/003 (2013.01); H04R 2400/07 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A force transducer comprising:
(a) an inner ferromagnetic core and an outer ferromagnetic core;
(b) a first magnetic pole having a first magnetic polarization and a first magnetic pole axial length, wherein
(i) the first magnetic pole has a first portion of the first magnetic pole that is connected to the inner ferromagnetic core and is facing the outer ferromagnetic core, wherein axial length of the first portion of the first magnetic pole is the first magnetic pole axial length, and
(ii) the first magnetic pole has a second portion of the first magnetic pole that is connected to the outer ferromagnetic core and is facing the inner ferromagnetic core, wherein axial length of the second portion of the first magnetic pole is the first magnetic pole axial length,
(c) a second magnetic pole having a second magnetic polarization and a second magnetic pole axial length, wherein
(i) the second magnetic pole has a first portion of the second magnetic pole that is connected to the inner ferromagnetic core and is facing the outer ferromagnetic core, wherein axial length of the first portion of the second magnetic pole is the second magnetic pole axial length,
(ii) the second magnetic pole has a second portion of the second magnetic pole that is connected to the outer ferromagnetic core and is facing the inner ferromagnetic core, wherein axial length of the second portion of the second magnetic pole is the second magnetic pole axial length,
(iii) the first magnetic polarization and the second magnetic polarization are oppositely directed, and
(iv) the first magnetic pole axial length is equal ±10% to the second magnetic pole axial length;
(d) a first movable coil having a first moveable coil axial length;
(e) a first moveable magnet operatively connected to the first moveable coil at an axial distance that is within 10% of the first movable coil axial length;
(f) a second moveable coil having a second moveable coil axial length, wherein
(i) the first moveable coil is movably located between (A) the first portion of the first magnetic pole connected to the inner ferromagnetic core and (B) the second portion of the first magnetic pole connected to the outer ferromagnetic core,
(ii) the second moveable coil is movably located between (A) the first portion of the second magnetic pole connected to the inner ferromagnetic core and (B) the second portion of the second magnetic pole connected to the outer ferromagnetic core, and
(iii) the first moveable coil length is equal ±10% to the second moveable coil length; and
(g) a second moveable magnet operatively connected to the second moveable coil at an axial distance that is within 10% of the second movable coil axial length.