IP Library Granted Patent US 9,264,789
Granted Patent B2
US 9,264,789 · App. 14/291,406 · Granted Feb 16, 2016

Equal expansion rate symmetric acoustic transformer

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Quick Facts
Patent No.
US 9,264,789
App. No.
14/291,406
Granted
Feb 16, 2016
Kind
B2
Abstract

An acoustic transformer includes at least one outer boundary wall. A plurality of inner walls are disposed within the outer boundary wall. The outer boundary wall and the inner walls define a substantially annular input opening divided by at least some of the inner walls into a plurality of circumferentially-spaced input sections. Each of the input sections has an inner circumferential side and an outer circumferential side. A substantially rectangular output opening is divided by at least some of the inner walls into a plurality of output sections. Each of a plurality of acoustic paths interconnects a respective one of the input sections with a respective one of the output sections. The acoustic paths maybe identical or individually unique in order to change the both the shape of the acoustic wavefront at the output and the energy distribution.

Claims (18)

1. An acoustic transformer, comprising:

an annular ring input, the annular ring input including a plurality of input sections spaced around the annular ring input, each input section defined by radially-oriented inner walls, an inner wall, and a boundary wall;

a substantially rectangular output opening divided into a plurality of output sections; and

a plurality of acoustic paths, each of the paths interconnecting a respective one of the input sections with a respective one of the output sections.

2. The acoustic transformer of claim 1 , wherein the substantially rectangular output opening is flat.

3. The acoustic transformer of claim 2 , wherein the plurality of acoustic paths are equal in length, producing a flat acoustical wavefront.

4. The acoustic transformer of claim 2 , wherein the lengths of the plurality of acoustic paths vary such that the acoustic paths to the output sections in a center area are shorter than the acoustic paths to the output sections on outer areas, producing a curved acoustical wavefront.

5. The acoustic transformer of claim 2 , wherein the lengths of the plurality of acoustic paths vary such that the acoustic paths to the output sections on outer areas are shorter than the acoustic paths to the output sections on a center area, producing a flat acoustical wavefront.

6. The acoustic transformer of claim 1 , wherein the substantially rectangular output opening is curved.

7. The acoustic transformer of claim 6 , wherein the plurality of acoustic paths are equal in length, producing a curved acoustical wavefront.

8. The acoustic transformer of claim 1 , wherein the plurality of input sections have equal areas.

9. The acoustic transformer of claim 8 , wherein the plurality of output sections have equal areas.

10. The acoustic transformer of claim 8 , wherein the areas of the plurality of output sections varies.

11. The acoustic transformer of claim 1 , wherein the plurality of input sections have unequal areas.

12. The acoustic transformer of claim 11 , wherein the plurality of output sections have equal areas.

13. The acoustic transformer of claim 11 , wherein the areas of the plurality of output sections varies.

14. The acoustic transformer of claim 1 , wherein the areas of the plurality of acoustic paths expand equally from the input sections to the output sections.

15. The acoustic transformer of claim 1 , wherein the areas of the plurality of acoustic paths expand unequally from the input sections to the output sections.

Assignments (4)
INTELLECTUAL PROPERTY SECURITY AGREEMENT Recorded May 15, 2026
From: ELECTRO-VOICE DYNACORD LLC
To: GLAS TRUST CORPORATION LIMITED
Reel/Frame 075643/0407 →
TERMINATION AND RELEASE OF SECURITY INTEREST IN INTELLECTUAL PROPERTY RECORDED AT REEL 73363, FRAME 0729 Recorded May 4, 2026
From: GLAS TRUST CORPORATION LIMITED
To: ELECTRO-VOICE DYNACORD LLC (F/K/A BOSCH SECURITY SYSTEMS, LLC, F/K/A BOSCH SECURITY SYSTEMS, INC.)
Reel/Frame 075499/0896 →
INTELLECTUAL PROPERTY SECURITY AGREEMENT Recorded Oct 28, 2025
From: BOSCH SECURITY SYSTEMS, LLC (FKA BOSCH SECURITY SYSTEMS, INC.)
To: GLAS TRUST CORPORATION LIMITED
Reel/Frame 073363/0729 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 13, 2014
From: DONARSKI, MATTHEW A.
To: BOSCH SECURITY SYSTEMS INC.; ROBERT BOSCH GMBH
Reel/Frame 033096/0236 →