# US 9,697,817 B2 · Tunable acoustic attenuation

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- Number: US 9,697,817 B2
- Document ID: US9697817B2
- Status: Granted
- Kind: B2
- Application number: 15/154,155
- Filed: 2016-05-13
- Published: 2016-11-17
- Granted: 2017-07-04
- Earliest claimed: 2015-05-14
- Assignees: ZIN Technologies
- Applicants: Zin Technologies, Inc.
- Inventors: Bart F. Zalewski; William Dial; Arthur J. Birchenough
- Web page: https://patentgrep.com/patent/US9697817B2

## CPC

- G10K 11/172: using resonance effects
- B33Y 10/00: Processes of additive manufacturing
- B33Y 80/00: Products made by additive manufacturing
- B29C 64/106: using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
- B29C 64/118: using filamentary material being melted, e.g. fused deposition modelling [FDM]
- E04B 2001/8433: {with holes in their face}
- G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- E04B: GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS (border constructions of opening in walls, floors or ceilings E06B1/00; {electromagnetic shielding H05K9/0001})

## Abstract

An acoustic attenuation device extends from a first end to a second end and includes first and second sheets. A plurality of webs positioned between the first and second sheets cooperates with the first and second sheets to form a series of sound attenuation chambers containing a volume and mass of fluid. A first panel secured to the sheets closes the chambers at the first end of the device. A second panel secured to the sheets closes the chambers at the second end of the device. The device further includes first and second openings associated with each chamber and through which excited fluid resonates. The first and second openings extend through the first sheet into each chamber. The first openings have an invariable cross-section. At least one of the second openings has an adjustable cross-section for varying a resonant frequency of the chamber.

## Claims

### Claim 1

An acoustic attenuation device extending from a first end to a second end comprising:
first and second sheets;
a plurality of webs positioned between the first and second sheets and cooperating with the first and second sheets to form a series of sound attenuation chambers containing a volume and mass of fluid;
a first panel secured to the sheets and closing the chambers at the first end of the device;
a second panel secured to the sheets and closing the chambers at the second end of the device; and
first and second openings associated with each chamber and through which excited air resonates, the first and second openings extending through the first sheet into each chamber, the first openings having an invariable cross-section and at least one of the second openings having an adjustable cross-section for varying a resonant frequency of the chamber.

### Claim 2 (depends on 1)

The acoustic attenuation device of claim 1 further comprising a frequency tuning mechanism associated with each second opening for adjusting the cross-section of each second opening.

### Claim 3 (depends on 2)

The acoustic attenuation device of claim 2, wherein the frequency tuning mechanism comprises:
a plurality of leaves; and
a controller to change a position the leaves to adjust the cross-section of each second opening.

### Claim 4 (depends on 3)

The acoustic attenuation device of claim 3, wherein the leaves cooperate to form a shutter, a spacing from a radially inner edge of the leaves to a center of the second opening being variable by the controller.

### Claim 5 (depends on 1)

The acoustic attenuation device of claim 1, wherein the cross-section of the second openings is adjustable after the device is fully assembled.

### Claim 6 (depends on 1)

The acoustic attenuation device of claim 1 further comprising at least one partition for dividing at least one of the chambers into chamber sections, each partition including an outer wall and an inner wall spaced from the inner wall by a space.

### Claim 7 (depends on 6)

The acoustic attenuation device of claim 6 further comprising a powdered material provided between the inner wall and the outer wall.

### Claim 8 (depends on 6)

The acoustic attenuation device of claim 6 wherein each partition includes damping fibers that dissipate energy to provide resistance to a flow of the excited air through the partition.

### Claim 9 (depends on 6)

The acoustic attenuation device of claim 6, wherein the at least one partition comprises a plurality of partitions that divides each chamber into a first chamber section and a second chamber section, all first chamber sections having the same length and all second chamber sections having the same length.

### Claim 10 (depends on 6)

The acoustic attenuation device of claim 6, wherein the at least one partition comprises a plurality of partitions that divides each chamber into a first chamber section, a second chamber section, and a third chamber section, all the first chamber sections having the same length, all the second chamber sections having the same length, and all the third chamber sections having the same length.

### Claim 11 (depends on 1)

The acoustic attenuation device of claim 1, wherein at least two of the second openings are different from one another.

### Claim 12 (depends on 1)

The acoustic attenuation device of claim 1 wherein the chambers comprise a plurality of first chambers in a first plane and at least one second chamber in a second plane different from the first plane.

### Claim 13

An acoustic attenuation device extending from a first end to a second end comprising:
first and second sheets;
a plurality of webs positioned between the first and second sheets and cooperating with the first and second sheets to form a series of sound attenuation chambers containing a volume and mass of fluid;
a first panel secured to the sheets and closing the chambers at the first end of the device;
a second panel secured to the sheets and closing the chambers at the second end of the device;
at least one partition for dividing at least one of the chambers into chamber sections, each partition including an outer wall and an inner wall spaced from the inner wall by an annular space;
first and second openings associated with each chamber and through which excited fluid resonates, the first and second openings extending through the first sheet into each chamber, the first openings having an invariable cross-section and at least one of the second openings having an adjustable cross-section for varying a resonant frequency of the chamber; and
a frequency tuning mechanism associated with each second opening for adjusting the cross-section of each second opening, the frequency tuning mechanism having a plurality of leaves and a controller for changing the spacing between the leaves to adjust the cross-section of each second opening for varying the resonant frequency of the chamber.

### Claim 14 (depends on 13)

The acoustic attenuation device of claim 13, wherein the leaves cooperate to form a shutter, the spacing from the leaves to a center of the second opening being variable by the controller.