US2733774A - Pessel - Google Patents
Pessel Download PDFInfo
- Publication number
- US2733774A US2733774A US2733774DA US2733774A US 2733774 A US2733774 A US 2733774A US 2733774D A US2733774D A US 2733774DA US 2733774 A US2733774 A US 2733774A
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- Prior art keywords
- water
- diaphragm
- coating
- cone
- insoluble
- Prior art date
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- Expired - Lifetime
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- 210000000188 Diaphragm Anatomy 0.000 description 48
- 239000000463 material Substances 0.000 description 46
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 40
- 239000011248 coating agent Substances 0.000 description 34
- 238000000576 coating method Methods 0.000 description 34
- 239000004372 Polyvinyl alcohol Substances 0.000 description 22
- 229920002451 polyvinyl alcohol Polymers 0.000 description 22
- 229920005989 resin Polymers 0.000 description 20
- 239000011347 resin Substances 0.000 description 20
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 18
- 239000000126 substance Substances 0.000 description 16
- 229920000126 Latex Polymers 0.000 description 12
- 229920001577 copolymer Polymers 0.000 description 12
- 230000002209 hydrophobic Effects 0.000 description 12
- 229920001187 thermosetting polymer Polymers 0.000 description 12
- 239000002657 fibrous material Substances 0.000 description 10
- 239000000080 wetting agent Substances 0.000 description 10
- 108010010803 Gelatin Proteins 0.000 description 8
- VEXZGXHMUGYJMC-UHFFFAOYSA-N HCl Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 8
- 239000011230 binding agent Substances 0.000 description 8
- 239000000839 emulsion Substances 0.000 description 8
- 229920000159 gelatin Polymers 0.000 description 8
- 239000008273 gelatin Substances 0.000 description 8
- 235000019322 gelatine Nutrition 0.000 description 8
- 235000011852 gelatine desserts Nutrition 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- BDERNNFJNOPAEC-UHFFFAOYSA-N propanol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 8
- PPBRXRYQALVLMV-UHFFFAOYSA-N styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 8
- QUBQYFYWUJJAAK-UHFFFAOYSA-N 1,3-bis(hydroxymethyl)urea Chemical compound OCNC(=O)NCO QUBQYFYWUJJAAK-UHFFFAOYSA-N 0.000 description 6
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 6
- 229920000459 Nitrile rubber Polymers 0.000 description 6
- 235000019270 ammonium chloride Nutrition 0.000 description 6
- KAKZBPTYRLMSJV-UHFFFAOYSA-N butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 6
- SEUDSDUUJXTXSV-UHFFFAOYSA-N dimethyl(oxo)silane Chemical compound C[Si](C)=O SEUDSDUUJXTXSV-UHFFFAOYSA-N 0.000 description 6
- 239000004744 fabric Substances 0.000 description 6
- 239000004816 latex Substances 0.000 description 6
- QDHHCQZDFGDHMP-UHFFFAOYSA-N monochloramine Chemical compound ClN QDHHCQZDFGDHMP-UHFFFAOYSA-N 0.000 description 6
- 229950005308 oxymethurea Drugs 0.000 description 6
- 229920002689 polyvinyl acetate Polymers 0.000 description 6
- 239000011118 polyvinyl acetate Substances 0.000 description 6
- 229920000915 polyvinyl chloride Polymers 0.000 description 6
- 239000004800 polyvinyl chloride Substances 0.000 description 6
- 240000008528 Hevea brasiliensis Species 0.000 description 4
- NLHHRLWOUZZQLW-UHFFFAOYSA-N acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 4
- 239000000835 fiber Substances 0.000 description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 229920001194 natural rubber Polymers 0.000 description 4
- 229920001568 phenolic resin Polymers 0.000 description 4
- 239000004753 textile Substances 0.000 description 4
- XSQUKJJJFZCRTK-UHFFFAOYSA-N urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 4
- PCOQKLFYWUVIRY-UHFFFAOYSA-N 1-propan-2-ylnaphthalene;sodium Chemical compound [Na].C1=CC=C2C(C(C)C)=CC=CC2=C1 PCOQKLFYWUVIRY-UHFFFAOYSA-N 0.000 description 2
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 2
- SXPWTBGAZSPLHA-UHFFFAOYSA-M Cetalkonium chloride Chemical compound [Cl-].CCCCCCCCCCCCCCCC[N+](C)(C)CC1=CC=CC=C1 SXPWTBGAZSPLHA-UHFFFAOYSA-M 0.000 description 2
- OIDPCXKPHYRNKH-UHFFFAOYSA-J Chrome alum Chemical compound [K]OS(=O)(=O)O[Cr]1OS(=O)(=O)O1 OIDPCXKPHYRNKH-UHFFFAOYSA-J 0.000 description 2
- 229920000877 Melamine resin Polymers 0.000 description 2
- 206010028334 Muscle spasms Diseases 0.000 description 2
- 229920001131 Pulp (paper) Polymers 0.000 description 2
- 208000005392 Spasm Diseases 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-L Sulphite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M acetate Chemical group CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 2
- 230000001680 brushing Effects 0.000 description 2
- 239000004202 carbamide Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 229960000228 cetalkonium chloride Drugs 0.000 description 2
- 239000007859 condensation product Substances 0.000 description 2
- -1 dioctyl ester Chemical class 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 229920005546 furfural resin Polymers 0.000 description 2
- 230000005660 hydrophilic surface Effects 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 239000010893 paper waste Substances 0.000 description 2
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 2
- 239000012260 resinous material Substances 0.000 description 2
- 230000000717 retained Effects 0.000 description 2
- 238000005201 scrubbing Methods 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- IYNDBHDAIOZDQC-UHFFFAOYSA-M sodium;1,2,3,4-tetrahydronaphthalene-1-sulfonate Chemical compound [Na+].C1=CC=C2C(S(=O)(=O)[O-])CCCC2=C1 IYNDBHDAIOZDQC-UHFFFAOYSA-M 0.000 description 2
- RTVVXRKGQRRXFJ-UHFFFAOYSA-N sodium;2-sulfobutanedioic acid Chemical compound [Na].OC(=O)CC(C(O)=O)S(O)(=O)=O RTVVXRKGQRRXFJ-UHFFFAOYSA-N 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 230000002522 swelling Effects 0.000 description 2
- 229920003051 synthetic elastomer Polymers 0.000 description 2
- 239000005061 synthetic rubber Substances 0.000 description 2
- 239000003643 water by type Substances 0.000 description 2
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
Description
Feb. 7, 1956 L. PESSEL 2,733,774
UNDERWATER ACOUSTIC DIAPHRAGM Filed Feb. 28. 1950 lNV NTOR BY 1.20am: Pain.
ATTORNEY United States Patent UNDERWATER ACOUSTIC DIAPHRAGM Leopold Pessel, Whitemarsll, Pa., assignor, by mesh-e assignments, to the United States of America as represented by the Secretary of the Navy Application February 28, 1950, Serial No. 146,651
3 Claims. (Cl. ISL-32) This invention relates to improved materials for making acoustic diaphragms and, more particularly, to acoustic materials intended to be used submerged in water.
Loudspeakers which are placed on the decks of submarines are necessarily exposed to water for extended periods of time whenever the submarine submerges. In the past, various types of loudspeakers have been used in this type of service, including cone-type speakers. All parts of the loudspeaker must be made of waterproof material. Waterproof materials suitable for loudspeaker cones have formerly been known and used. These cones, however, have been found to suffer from disadvantages in battle use. It has been found that ordinary waterproof speaker cones are often punctured by nearby, underwater explosions when the cone is submerged. A cone which has thus been punctured is useless for further service and must be replaced.
The present invention relates to an acoustic material comprising a web of flexible, fibrous material impregnated with a water-insoluble resin and having a surface coating of a water-insoluble, hydrophilic, film-forming substance. The invention also includes acoustic diaphragrns made of this improved material.
One object of the present invention is to provide an improved waterproof material suitable for loudspeaker cones intended for underwater use.
Another object of the invention is to provide an improved waterproof acoustic diaphragm.
Another object of the invention is to provide an improved loudspeaker cone for underwater use.
Another object of the invention is to provide an improved loudspeaker cone which will resist the effects of underwater explosions.
These and other objects will be more apparent and the invention will be more readily understood from the following detailed description, including the drawings, of which:
Fig. 1 is a plan view of one form of acoustic diaphragm made of the improved material of the present invention, and
Fig. 2 is a cross section view taken along the line 22 of Fig. 1.
Acoustic diaphragrns, such as used in loudspeaker cones, are usually made of a thin, flexible web of molded, felted, fibrous, cellulosic material. Small percentages of resinous binders may be mixed with the fibrous material. The cellulosic material is usually a good grade of wood pulp, which may be combined with various amounts of less expensive fibers, such as waste paper or textile fibers. Acoustic diaphragms may also be molded out of impregnated textile fabrics or even fine mesh wire screen material. If the diaphragm is to be exposed to water or if it must be submerged in water, the fibrous base ma.- terial is usually impregnated with relatively high percentages of waterproof binder. The waterproof binder is usually a water-insoluble, thermosetting resin. Any water-insoluble, thermosetting, resin may be used. Preferred examples are condensation products such as urea ice formaldehyde resins, phenol formaldehyde resins, melamine formaldehyde resins, and phenol furfural resins. These and other thermosetting resins generally have waterrepellent, or hydrophobic, properties.
It has been found, as previously mentioned, that speaker cones made of fibrous materials impregnated with these resins are subject to puncture if used in places subject to underwater explosions. The present invention is a result of the discovery that rupturing of the cones by explosions is due to entrapment of air bubbles on the surface of the cone. Air bubbles are trapped due to the hydrophobic properties of the waterproof resin binder. Apparently, when an explosion occurs nearby in the water, any entrapped air bubbles upon the surface of the cone rapidly contract and deliver a hammer-like blow to the surface of the cone over a small area. The blow often has suflicient force to cause a puncture. If an attempt is made to make the diaphragm out of material strong enough to withstand the puncturing force, the cone usually does not have sufficiently good acoustic response.
It has been found that the waterproof properties may be retained and, at the same time, the entrapment of air bubbles prevented by providing the surface of a waterproofed speaker cone with a coating of a water-insoluble, hydrophilic material. This is illustrated in the drawing wherein a typical loudspeaker cone 2, having an outer surface 4 and an inner surface 6, is provided with a coating 8 on the outer surface and a similar coating 10 on the inner surface.
The coating must be a water-insoluble, hydrophilic substance which adheres well to the base material. A hydrophilic substance is one which is readily wetted by water. That is, if a spray of water is directed to a surface composed of the substance, it will form a uniform film over the surface instead of gathering in droplets, as would be the case with a hydrophobic material.
A preferred coating substance for the present invention comprises an insolubilized and partially hydrolized polyvinyl alcohol. A suitable insolubilized polyvinyl alcohol can be made by first saponifying about 50% f the acetate groups of polyvinyl acetate. This polyvinyl alcohol is then made increasingly water resistant by giving it an insolubilizing treatment by any one of a number of well known methods. For example, the partially hydroiized polyvinyl alcohol may be acidified with hydrochloric acid to a pH of 4-5. A coating of this material may then be applied to the diaphragm by any convenient method, such as by dipping, spreading, or brushing. After draining off the excess solution, the diaphragm is heated in an oven for about 30 minutes at C. The resultant surface is both waterproof and also suficiently hydrophilic to prevent trapping of air bubbles when the diaphragm is under Water.
The partially hydrolized polyvinyl alcohol may also be insolubilized by heating it with a small proportion of dimethylol urea, using ammonium chloride as a catalyst. An acoustic diaphragm may be provided with a coating of the material by, first, mixing the three ingredients, applying the mixture to the surface of the diaphragm, and heating for at least 15 minutes at 150 C. More specifically, the above solution may be made by first dissolving 10 parts by weight of the partially hydrolized polyvinyl alcohol, previously referred to, in a mixture composed of 100 parts by weight of any suitable solvent such as ethanol or propanol and parts by weight of water. A second solution is made up by dissolving 5 parts by weight of dimethylol urea in 100 parts by weight of water. A third solution is made up by dissolving 5 parts by weight of ammonium chloride in 100 parts by weight of water. The coating mixture is made by mixing 5 parts by volume of the polyvinyl alcohol solution with 1 part by volume of the dimethylol urea solution, 1 part by volume spasms of the ammonium chloride solution, 10 parts by volume of water, and 12 parts by volume of ethanol or propanol. In a preferred form of carrying out the invention, a speaker cone composed of a cloth impregnated with phenol formaldehyde resin was treated with two coats of the above described solution. Each coat was permitted to dry in air and then each was heated for 15 minutes at 150 C. The cone was then further treated with a solution comprising parts by volume of the ethanol or propanol solution of polyvinyl alcohol, described above, 15 parts by volume of alcohol (such as ethanol or propanol) parts by volume of water and 0.5 part by volume of 10% hydrochloric acid. After treating with this solution, applied as a coating, the diaphragm was again permitted to air dry and then heated for minutes at 150 C.
It was also found that the hydrophilic properties of the cones made as above described could be improved somewhat by scrubbing them in Water with a soft bristle brush until the surface became uniformly wetted by the water.
In general, the polyvinyl alcohol should be hydrolized to the extent that it is still water-wettable. The partially hydrolized material should then be insolubilized just so that it is substantially insoluble in water. Any polyvinyl alcohol meeting these two requirements can be used in the present invention.
Although water-wettable, water-insoluble, polyvinyl alcohol is the preferred coating material for use in the invention, other materials can also be used. A film of rubber latex may be used, for example. This may be applied to the surfaces of a resin-impregnated acoustic diaphragm, either from aqueous emulsion or organic solvent solution. The volatile components are permitted to evaporate. An example of a suitable rubber latex is a copolymer of butadiene and acrylonitrile. Any of the commercially available copolymers may be used, such as Hycar OR-15 or Hycar OR25. Copolymers of butadiene and styrene may also be used. An example of this type of copolymer is Hycar OS10. The latex films do not adhere firmly to all types of resinous surfaces, however. In general, the rubber latex which is used may be any synthetic rubber having hydrophilic properties. Natural rubber latex may also be used.
Another example of a film-forming substance which can be used as the water-wettable coating of the present invention is an emulsion of a polyvinyl chloride. Various wetting agents may be incorporated with the emulsion to improve its spreading properties when it is applied to the diaphragm. Suitable wetting agents include isopropyl naphthalene sodium sulfonate, dioctyl ester of sodium sulfosuccinic acid, sodium tetrahydronaphthalene sulfonate, and cetyl dimethyl benzyl ammonium chloride. Any other compatible wetting agent may also be used. As an example of use, an aqueous emulsion of polyvinyl chloride was prepared having 56.5% solids content by weight and containing 1.5% by weight wetting agent. A thin coating of this composition was applied to both surfaces of a waterproof speaker cone and the cone was then heated at 150 C. for 15 minutes. The wetting agent can be omitted if desired. It does not affect the hydrophilic properties of the dried film to any extent.
Still another example of a hydrophilic, film-forming, Water-insolublc substance which can be used as the surface coating in the materials of the present invention is hardened gelatin. The gelatin can be applied as a water sol and hardened by any wellknown method such as soaking in a solution of chrome alum, or a dichrornate. Although resistant to the swelling action of water, the hardened, insoluble gelatin is hydrophilic.
There has thus been described an improved material having Waterproof and water-wettable properties. Although the material is suitable for use in any application requiring a water-wettable but water-insoluble surface, it is particularly adapted to be used as the acoustic diaphragm in a loudspeaker which is submerged in water at least a part of the time. There has also thus been described an improved acoustic diaphragm for underwater use and not readily subject to rupture due to nearby underwater explosions.
l claim as my invention:
1. in underwater sound equipment, an acoustic diaphragm capable of resisting the shock of nearby underwater explosions, said diaphragm comprising a molded web of porous, flexible fabric impregnated with a waterinsoluble, hydrophobic, thermosetting resin and having an exposed hydrophilic coating comprising a partially hydrolized, insolubilized polyvinyl acetate.
2. in underwater sound equipment, a loudspeaker diaphragm including a neck portion, a flanged rim and a main body portion of conical shape, said diaphragm comprising a molded web of porous flexible, fibrous material impregnated with a water-insoluble, hydrophobic, thermosetting resin and having an exposed surface coating consisting essentially of a water-insoluble, hydrophilic, film-forming, resinous material.
3. 1n underwater sound equipment, a loudspeaker diaphragm including a neck portion, a flanged rim and a main body portion of conical shape, said diaphragm comprising a web or" flexible, porous, fibrous material impregnated with a water-insoluble, hydrophobic, thermosetting resin and having an exposed hydrophilic surface coating comprising a substance selected from the class consisting of partially hydrolized and insolubilized polyvinyl acetate, natural rubber latex, copolymers of butadicne and acrylonitrile, copolymers of butadiene and styrene, polyvinyl chloride and hardened gelatin.
References Cited in the file of this patent UNITED STATES PATENTS 1,377,677 Gelbert May 10, 1921 2,006,830 Hawley July 2, 1935 2,028,126 Warren Jan. 14, 1936 2,099,154 Waters Nov. 16, 1937 2,102,150 Hammer Dec. 14, 1937 2,123,155 Groif July 5, 1938 2,302,178 Brennan Nov. 17, 1942 2,309,027 Toland Jan. 19, 1943 2,369,450 Fisher et a1. Feb. 13, 1945 2,405,038 Jennings July 30, 1946 2,464,783 Dillehay Mar. 22, 1949 2,493,255 Lillis Jan. 3, 1950 2,504,124 Hicks Apr. 18, 1950 2,684,726 Ebaugh et al. July 27, 1954 FOREIGN PATENTS 312,409 Great Britain May 30, 1929 wars-n
Publications (1)
Publication Number | Publication Date |
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US2733774A true US2733774A (en) | 1956-02-07 |
Family
ID=3443336
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US2733774D Expired - Lifetime US2733774A (en) | Pessel |
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US (1) | US2733774A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3003191A (en) * | 1958-09-02 | 1961-10-10 | Harold J Luth | Method of making a transducer diaphragm |
US3717218A (en) * | 1970-04-07 | 1973-02-20 | Sato Hisao | Loudspeaker |
US20050254778A1 (en) * | 1999-10-04 | 2005-11-17 | Pettersen Carl W | System for providing wireless waterproof audio |
US20070280053A1 (en) * | 1999-10-04 | 2007-12-06 | H2O Audio, Inc. | Waterproof audio headset |
US20100006314A1 (en) * | 2008-07-11 | 2010-01-14 | H2O Audio, Inc. | Waterproof enclosure for audio device |
Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1377677A (en) * | 1921-05-10 | chicago | ||
GB312409A (en) * | 1928-03-01 | 1929-05-30 | Robert Alexander Eliot | Improvements in or relating to diaphragms for loud-speakers and the like |
US2006830A (en) * | 1930-12-24 | 1935-07-02 | Jesse B Hawley | Sound reproducing diaphragm |
US2028126A (en) * | 1930-07-07 | 1936-01-14 | Carbide & Carbon Chem Corp | Phonograph record |
US2099154A (en) * | 1934-05-07 | 1937-11-16 | Econo Products Inc | Shrinkage control of flexible printing plates and the like |
US2102150A (en) * | 1934-11-06 | 1937-12-14 | Telefunken Gmbh | Diaphragm |
US2123155A (en) * | 1931-07-15 | 1938-07-05 | Union Carbide & Carbon Corp | Composite material |
US2302178A (en) * | 1940-11-12 | 1942-11-17 | Joseph B Brennan | Acoustic diaphragm |
US2309027A (en) * | 1941-01-02 | 1943-01-19 | William C Toland | Planographic plate process |
US2369450A (en) * | 1939-06-14 | 1945-02-13 | Gardner Richardson Co | Paper manufacture |
US2405038A (en) * | 1943-12-24 | 1946-07-30 | Du Pont | Carburetor diaphragm |
US2464783A (en) * | 1945-02-28 | 1949-03-22 | Richardson Co | Rubber coated resin saturated sheet and process of making the same |
US2493255A (en) * | 1943-11-08 | 1950-01-03 | Victor Mfg & Gasket Co | Fluid seal |
US2504124A (en) * | 1944-07-15 | 1950-04-18 | William L Hicks | Self-cooling bag for liquids |
US2684726A (en) * | 1949-05-27 | 1954-07-27 | Us Navy | Wetting agent |
-
0
- US US2733774D patent/US2733774A/en not_active Expired - Lifetime
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1377677A (en) * | 1921-05-10 | chicago | ||
GB312409A (en) * | 1928-03-01 | 1929-05-30 | Robert Alexander Eliot | Improvements in or relating to diaphragms for loud-speakers and the like |
US2028126A (en) * | 1930-07-07 | 1936-01-14 | Carbide & Carbon Chem Corp | Phonograph record |
US2006830A (en) * | 1930-12-24 | 1935-07-02 | Jesse B Hawley | Sound reproducing diaphragm |
US2123155A (en) * | 1931-07-15 | 1938-07-05 | Union Carbide & Carbon Corp | Composite material |
US2099154A (en) * | 1934-05-07 | 1937-11-16 | Econo Products Inc | Shrinkage control of flexible printing plates and the like |
US2102150A (en) * | 1934-11-06 | 1937-12-14 | Telefunken Gmbh | Diaphragm |
US2369450A (en) * | 1939-06-14 | 1945-02-13 | Gardner Richardson Co | Paper manufacture |
US2302178A (en) * | 1940-11-12 | 1942-11-17 | Joseph B Brennan | Acoustic diaphragm |
US2309027A (en) * | 1941-01-02 | 1943-01-19 | William C Toland | Planographic plate process |
US2493255A (en) * | 1943-11-08 | 1950-01-03 | Victor Mfg & Gasket Co | Fluid seal |
US2405038A (en) * | 1943-12-24 | 1946-07-30 | Du Pont | Carburetor diaphragm |
US2504124A (en) * | 1944-07-15 | 1950-04-18 | William L Hicks | Self-cooling bag for liquids |
US2464783A (en) * | 1945-02-28 | 1949-03-22 | Richardson Co | Rubber coated resin saturated sheet and process of making the same |
US2684726A (en) * | 1949-05-27 | 1954-07-27 | Us Navy | Wetting agent |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3003191A (en) * | 1958-09-02 | 1961-10-10 | Harold J Luth | Method of making a transducer diaphragm |
US3717218A (en) * | 1970-04-07 | 1973-02-20 | Sato Hisao | Loudspeaker |
US20050254778A1 (en) * | 1999-10-04 | 2005-11-17 | Pettersen Carl W | System for providing wireless waterproof audio |
US20070280053A1 (en) * | 1999-10-04 | 2007-12-06 | H2O Audio, Inc. | Waterproof audio headset |
US7755975B2 (en) * | 1999-10-04 | 2010-07-13 | H2O Audio, Inc. | System for providing wireless waterproof audio |
US20100006314A1 (en) * | 2008-07-11 | 2010-01-14 | H2O Audio, Inc. | Waterproof enclosure for audio device |
US8223997B2 (en) | 2008-07-11 | 2012-07-17 | H2O Audio, Inc. | Waterproof enclosure for audio device |
US9426560B2 (en) | 2008-07-11 | 2016-08-23 | Incipio, Llc | Waterproof enclosure for audio device |
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