# US 11,122,365 B2 · Acoustic protective cover assembly containing a retracted membrane material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,122,365 B2 - Document ID: US11122365B2 - Status: Granted - Kind: B2 - Application number: 16/340,622 - Filed: 2017-10-20 - Published: 2019-08-29 - Granted: 2021-09-14 - Earliest claimed: 2016-10-21 - Assignees: W. L. Gore & Associates, Inc. - Applicants: W. L. Gore & Associates, Inc. - Inventors: Scott Zero; Zachary Lampert; Theresa Tonge - Web page: https://patentgrep.com/patent/US11122365B2 ## CPC - H04R 1/44: Special adaptations for subaqueous use, e.g. for hydrophone - G01F 1/36: the pressure or differential pressure being created by the use of flow constriction - G01F 5/00: Measuring a proportion of the volume flow - G01F 25/10: of flowmeters - H04R 1/023: {Screens for loudspeakers} - B01D 39/1692: {Other shaped material, e.g. perforated or porous sheets} - B32B 5/02: characterised by structural features of a {fibrous or filamentary} layer {(layer formed of metallic wires B32B15/02; layer formed of natural mineral fibres B32B19/02; layer formed of wood fibres B32B21/02)} - D04H 1/50: by treatment to produce shrinking, swelling, crimping or curling of fibres (in combination with needling D04H1/482) - H04R 1/086: {Protective screens, e.g. all weather or wind screens} - H04R 1/283: {using a passive diaphragm} - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - D04H: MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL (weaving D03; knitting D04B; braiding D04C; net-making D04G; sewing D05B; tufting D05C; finishing non-woven fabrics D06); FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING {; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION}(non-woven fabrics having an intermediate or external layer of a different kind, e.g. of woven fabric, B32B) ## Abstract An acoustic protective cover assembly can include a retracted membrane material traversing across an acoustic pathway defined by an opening in a housing. The retracted membrane material can include a fibril structure characterized by serpentine fibrils. ## Claims ### Claim 1 A sound-transmissive cover for an acoustic device, the sound-transmissive cover configured to connect to the acoustic device, the sound-transmissive cover comprising: a retracted membrane material, wherein the retracted membrane material has an acoustic insertion loss of less than 6 dB at 1 kHz and a water entry pressure (WEP) of at least 9.8 kPa, wherein the retracted membrane material has a microstructure, wherein the microstructure includes serpentine fibrils, wherein the serpentine fibrils are obtainable by a retraction process which reduces an area ratio, wherein the retraction process is a separate process from an expansion process, wherein the serpentine fibrils comprise S-shaped regions that are curved in more than one direction, and wherein the serpentine fibrils have a width of 1 micron or less. ### Claim 2 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an ATEQ airflow rate of at least 10 L/hr per 2.0 cm2. ### Claim 3 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an acoustic insertion loss of less than 5 dB at 1 kHz. ### Claim 4 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an area density greater than or equal to 6 g/m2, and a thickness less than 15 μm. ### Claim 5 (depends on 1) The sound-transmissive cover of claim 1, wherein the cover is waterproof. ### Claim 6 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an area ratio of less than 0.75:1 relative to an initial area of a precursor membrane. ### Claim 7 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has a mass per area of at least 6.9 g/m2 and a thickness of less than 16 μm. ### Claim 8 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material is air permeable. ### Claim 9 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material comprises a thermally retracted membrane. ### Claim 10 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material comprises a solvent retracted material. ### Claim 11 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material comprises an expanded fluoropolymer membrane. ### Claim 12 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an ATEQ airflow rate of at least 15 L/hr per 2.0 cm2. ### Claim 13 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an acoustic insertion loss of less than 4 dB at 1 kHz. ### Claim 14 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an acoustic insertion loss of less than 3 dB at 1 kHz. ### Claim 15 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an acoustic insertion loss of less than 1 dB at 1 kHz. ### Claim 16 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an area density greater than or equal to 7 g/m2. ### Claim 17 (depends on 1) The sound-transmissive cover of claim 1, wherein the retracted membrane material has an area density less than 15 g/m2. ### Claim 18 A protective cover assembly for an acoustic device, the protective cover assembly configured to connect to the acoustic device, the protective cover assembly comprising: a housing, wherein the housing has an opening configured to pass acoustic waves between an exterior of the housing and an acoustic cavity therein; and a retracted membrane, wherein the retracted membrane has an acoustic insertion loss of less than 6 dB at 1 kHz and a water entry pressure (WEP) of at least 9.8 kPa, wherein the retracted membrane material has a microstructure, wherein the microstructure includes serpentine fibrils, wherein the serpentine fibrils are obtainable by a retraction process which reduces an area ratio, wherein the retraction process is a separate process from an expansion process, wherein the serpentine fibrils comprise S-shaped regions that are curved in more than one direction, and wherein the serpentine fibrils have a width of 1 micron or less. ### Claim 19 (depends on 18) The protective cover assembly of claim 18, further comprising: an acoustic device connected to the acoustic cavity, wherein the acoustic device is configured to generate the acoustic waves, receive the acoustic waves, or generate and receive the acoustic waves. ### Claim 20 A sound-transmissive cover for an acoustic device, the sound-transmissive cover configured to connect to the acoustic device, the sound-transmissive cover comprising: an expanded fluoropolymer membrane, wherein the expanded fluoropolymer membrane comprises a retracted membrane material, wherein the retracted membrane material has a microstructure, wherein the microstructure includes serpentine fibrils, wherein the serpentine fibrils are obtainable by a retraction process which reduces an area ratio, wherein the retraction process is a separate process from an expansion process, wherein the serpentine fibrils comprise S-shaped regions that are curved in more than one direction; and wherein the retracted membrane material has an acoustic insertion loss of less than 6 dB at 1 kHz, and a water entry pressure (WEP) of at least 9.8 kPa, and wherein the retracted membrane material has an area ratio of less than 0.75:1 relative to an initial area of a precursor membrane.