Planar flexible voice coil suspension

1. An acoustic transducer comprising:

a housing defining at least one stationary electrical contact;

a magnet assembly fixedly mounted in said housing and defining an air gap extending around a central axis;

a voice coil having at least one electric terminal;

spider means for suspending said voice coil for axial movement in said air gap, said spider means comprising:

a sheet of flexible dielectric material formed to define a circular flexure portion and having an elongate connector portion extending therefrom to an outer end; and

at least one flat electrically conductive path formed on said dielectric sheet extending from said outer end adapted for connection to said stationary contact to a connection location on said flexure portion adapted for connecting to said electric terminal;

wherein said flexure portion comprises a concentric outer ring a concentric inner ring; and wherein

said sheet of dielectric material defines a set of links connecting said outer ring to said inner ring and wherein said flexure portion further comprises a concentric intermediate ring disposed in between said concentric outer and inner rings; and wherein said set of links connecting said outer ring to said inner ring comprises a first set of radial links connecting said outer ring to said intermediate ring and a second set of radial links connecting said intermediate ring to said inner ring.

2. The transducer of claim 1 wherein said flexure portion is configured to exhibit high axial compliance and high radial stiffness.

3. The transducer of claim 1 wherein said first set of radial links is comprised of N links substantially uniformly distributed around said central axis and wherein said second set of radial links is comprised of M links substantially uniformly distributed around said central axis.

4. The transducer of claim 1 wherein

said connection location comprises a tab extending inwardly from said inner ring.

5. The transducer of claim 1 , further comprising:

a flexible diaphragm having a central area and a circumferential edge;

means for orienting said diaphragm perpendicular to said central axis for retention around said circumferential edge; and

means for coupling said voice coil to said diaphragm central area for flexing said diaphragm.

6. The transducer of claim 1 wherein said sheet of dielectric material has a thickness on the order of 0.001 inches.

7. The transducer of claim 1 wherein said flat conductive path has a thickness on the order of 0.0007 inches.

8. A spider for supporting a voice coil for linear axial motion comprising:

a sheet of flexible dielectric material shaped to form a circular flexure portion and an elongate connector portion extending radially from said flexure portion to an outer end; and

a flat electrically conductive path formed on said dielectric sheet extending from said outer end to a connection location on said flexure portion and wherein said outer end is adapted for connection to a stationary electric contact and said connection location is adapted for connection to a movable electric terminal;

wherein said flexure portion comprises a concentric outer ring, a concentric inner ring, and a concentric intermediate ring; and wherein

said sheet of dielectric material defines a first set of radial links connecting said outer ring to said intermediate ring and a second set of radial links connecting said intermediate ring to said inner ring.

9. The transducer of claim 8 , wherein

said connection location comprises a tab extending inwardly from said inner ring.

10. The transducer of claim 8 wherein said sheet of dielectric material has a thickness on the order of 0.001 inches.

11. The transducer of claim 8 wherein said flat conductive path has a thickness on the order of 0.0007 inches.