US 7,551,749 B2Granted

Baffle vibration reducing

AssigneeBose Corporation

InventorsMichael D. Rosen, Richard Warren Little

Life of this patent

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Abstract

An electro-acoustic transducer includes a magnet assembly having a first magnetic flux gap and a second magnetic flux gap. A first voice coil is positioned in the first magnetic flux gap. A first diaphragm is mechanically coupled to the first voice coil and to a frame. The first voice coil moves the first diaphragm in a first direction in response to receiving a first input signal. A second voice coil is positioned in the second magnetic flux gap. A second diaphragm is mechanically coupled to the second voice coil and to the frame. The second voice coil moves the second diaphragm in a second direction that is substantially opposite to the first direction in response to receiving a second input signal. The movement of the second diaphragm reduces a vibration imparted to the frame by the movement of the first diaphragm.

Claims17

Dependent claims

An electro-acoustic transducer comprising:

a) a magnet assembly providing a first magnetic flux gap and a second magnetic flux gap;
b) a first voice coil positioned in the first magnetic flux gap;
c) a first diaphragm that is mechanically coupled to the first voice coil and to a frame, the first voice coil constructed to move the first diaphragm in a first direction in response to receiving a first input signal;
d) a second voice coil positioned in the second magnetic flux gap;
and
e) a second diaphragm that is mechanically coupled to the second voice coil and to the frame, the second voice coil constructed to move the second diaphragm in a second direction in response to receiving a second input signal, the movement of the second diaphragm reducing a vibration imparted to the frame by the movement of the first diaphragm when the first direction is substantially opposite to the second direction,
the first and second diaphragms being located on a common side of the magnet assembly,
wherein the first input signal applied to the first voice coil generates a first magnetic field and the second input signal applied to the second voice coil generates a second magnetic field, the first and second voice coils being wound such that the second magnetic field has opposite polarity to the first magnetic field at a point where the first and second magnetic fields cause modulation of magnetic flux in at least one of the first and the second magnetic flux gaps when the input signals are such that the first and second directions are substantially opposite.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/999,419Filed 30 Nov 2004 · continuation in part
Priority: 23 Aug 2002
Published: US 2005/0111673 A126 May 2005
Granted: 23 Jun 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

H04R 1/227
For obtaining desired frequency characteristic only: using transducers reproducing the same frequency band
B60R 11/0217
For radio sets, television sets, telephones, or the like; Arrangement of controls thereof: for loud-speakers
B60R 13/02
Elements for body-finishing, identifying, or decorating; Arrangements or adaptations for advertising purposes: internal Trim mouldings ; Internal…
H04R 1/2873
Reduction of undesired resonances, i.e. standing waves within enclosure, or of undesired vibrations, i.e. of the enclosure itself: for loudspeaker…

Family

Application10/226,507Parent of this continuation-in-part · filed 23 Aug 2002
US 2005/0111673 A1Pre-grant publication · published 26 May 2005
US 6,985,593 B2Parent of this continuation-in-part
US 2004/0035635 A1Published application
US 7,551,749 B2This patent

From the US filing history. Foreign family members aren’t listed.