Acoustic transducer with vibration damping

• US 10,462,573 B2
• Filed: 10/16/2018
• Issued: 10/29/2019
• Est. Priority Date: 07/28/2017
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: Pircaro, Mark A.
• Primary Examiner(s): Nguyen, Khai N.
• Application Number:
  US16/161,151
• Publication Number:
  US 20190052971A1
• Time in Patent Office: 378 Days
• Field of Search: 381423
• CPC Class Codes: H04R 1/2857 for loudspeaker transducers
• CPC Class Codes: H04R 2231/001 Moulding aspects of diaphragm or surround
• CPC Class Codes: H04R 2231/003 Manufacturing aspects of the outer suspension of loudspeaker or microphone diaphragms or of their connecting aspects to said diaphragms
• CPC Class Codes: H04R 2307/204 Material aspects of the outer suspension of loudspeaker diaphragms
• CPC Class Codes: H04R 2307/207 Shape aspects of the outer suspension of loudspeaker diaphragms
• CPC Class Codes: H04R 31/003 for diaphragms or their outer suspension
• CPC Class Codes: H04R 7/06 comprising a plurality of sections or layers
• CPC Class Codes: H04R 7/12 Non-planar diaphragms or cones
• CPC Class Codes: H04R 7/122 comprising a plurality of sections or layers
• CPC Class Codes: H04R 7/127 dome-shaped
• CPC Class Codes: H04R 7/20 Securing diaphragm or cone resiliently to support by flexible material, springs, cords, or strands
• CPC Class Codes: H04R 9/06 Loudspeakers

Abstract

Circumferential mode vibrations, in a diaphragm of an acoustic transducer, are damped by defining at least one elongated opening extending radially along a portion of a length from the central area to the outer perimeter being covered by a material having higher damping properties than the material of the cone.

Claims

1. An acoustic transducer, comprising:

a diaphragm made of a first material having a central area, an outer perimeter, a center of mass, and an axis of symmetry; and

at least one elongated depression formed in the diaphragm, extending substantially radially along a portion of a length from the central area to the outer perimeter and including a first wall having a first depth, a second wall having a second depth, and a floor extending between the first wall and the second wall.

2. The acoustic transducer of claim 1, wherein the first depth and the second depth are different.

3. The acoustic transducer of claim 1, wherein the at least one elongated depression is covered with a second material having relatively higher damping characteristics than the first material.

4. The acoustic transducer of claim 1, further comprising a surround, having relatively higher damping characteristics than the first material, arranged circumferentially about the outer perimeter of the diaphragm, wherein the surround comprises at least one projection extending from the outer perimeter toward the central area of the diaphragm, wherein the at least one projection is arranged to cover the at least one elongated depression.

5. The acoustic transducer of claim 4, wherein the at least one projection comprises a plurality of projections and the at least one elongated depression comprises a plurality of elongated depression, each projection of the plurality of projections covering a respective elongated depression of the plurality of elongated depressions.

6. The acoustic transducer of claim 5 wherein the surround is comprised of a foam material.

7. The acoustic transducer of claim 1 further comprising at least one tinsel, wherein the diaphragm has a center of mass and an axis of symmetry, the at least one tinsel being and the at least one elongated depression, at least in part, being located on the opposite side of the axis of symmetry such that the center of mass of the diaphragm lies on or near the axis of symmetry.