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Publication numberUS1730532 A
Publication typeGrant
Publication dateOct 8, 1929
Filing dateNov 30, 1928
Priority dateNov 30, 1928
Publication numberUS 1730532 A, US 1730532A, US-A-1730532, US1730532 A, US1730532A
InventorsRobbins Percy A
Original AssigneeRobbins Percy A
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Acoustic transformer
US 1730532 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Oct. 8, 1929. P. A. ROBBINS ACOUSTIC TRANSFORMER Filed Nov. 30, 1928 .Znlen/Zz I I PQfiZZim /m Patented Oct. 8, 1929* I UNITED STATES PATENT. OFFICE PERCY A. nonam's, onnronrann ranx, ILLINOIS ACOUETIC TRANSFORMER Apialicatlon fled November 30, 1928. Serial No. 522,899.

I disclosed a closed cham' er containing a gaseous medium havinga greater powertransmitting capacit pheric, pressure in w ich chamber is totally immersed a vibratable diaphragm from which or to which vibrations pass solely through the gaseous medium a) orfrom a second diaphragm exposed-at one side to the 7 atmosphere and at the other side sure within the chamber.

My object in the presefit invention is to provide a simple form of the invention which is cheaply and easily made, and which gives a maximum area to the second diaphragm obtainable within given over all dimensions of the apparatus.

\ I attain my object by reducing the rigid part of the chamber to such dimensions as sufiice only for the connection and support of the parts, and by utilizing, to complete to the presthe chamber and form the diaphragm, a substantially spherical shell formed of a lickible elastic material such as thin rubber.

The invention is hereinafter more specifically described and illustrated in the accompanyin drawing which is a vertical section of the evice. y

. Referring to the drawing, 1 is a diaphragm operated by the electro-magnet 22. The diaphragm is held in place by the ring 4. and the whole is mounted on the cup 3. This is a usual type of loud speaker unit and I, make no claim thereto as any suitable type may be used. I

The cup 3 is screwedonto a tube 6, which is screwed into a connecting nipple 7 which is screwed onto a stand tube 8 screwed into the V base 9. Electricconductors 55 connect'the magnet 22 with the connecting bolts 18-18 Y which on their outer ends are connected to electric conductors 19-19 which supply, the current for operating the diaphragm 1.

15 is a circular disk of wood or other nonconductor of electricity forming the base of the gas chamber of the device. 16 is a rubber balloon similar to those used for toys but than air at atmos-" having a somewhat larger neck opening. The balloon neck is stretched over the diaphragm and cup 3, and is then stretched over the disk 15 to engage in a peripheral groove around I the latter. A binding string or elastic 17 holds the balloon neck tightly in place making a gas tight joint.

10 is a branch tube fitted into the tube. 8 and having the valve seat 12 and the valve 11 mounted internally. 13 is a spring for holding the valvedn place. I make no claim for novelty in the construction of tube 10 and the valve, and any arran ement similar to an automobile tire valve wi I serve the purpose. 14 is the usual cap for closing the end of tube 10. r

I wish to surround the diaphragm with a heavy dense gas, and one way to accomplish this is to use the carbon dioxide of the human breath. Respired air is blown in through the tube 10. The tube 8 is packed with any porous absorbent for removing moisture from the stream of air. The density of the air in the balloon 16 may be regulated by the pressure of inflation. If greater pressure is reuired, more respired air isblown in through t e tube 10. If decreased pressure is required, some of the air can be released by pushing on the stem of the valve 11.

202O are holes in the tube 6 for allowing the air to flow into the interior of the balloon. The upper end of the tube 6 communicates withthe interior of the cup 3 so that the cup is filled with gas under pressure and the diaphragm 1 is in contact with the same pressure and density of gas on both of its sides.

Apparatus constructed as described will satisfactorily attain the objects of my invention as set forth in the specigcation.

What I claim as my invention is:

1; An acoustic transformer comprising a base; a substantially spherical thin shell connected withthe base and forming therewith a gas tight chamber; means for admitting a gaseous medium under pressure into said chamber; and a vibratahle diaphragm immersed in said gaseous medium and entirely enclosed by said chamber.

2. An acoustic transformer comprising a base; a substantially spherical shell of elastic material connected with the base and forming therewith a gas tight chamber; means for admitting a gaseous medium under pressure into said chamber; and a vibratable diaphragm immersed insaid gaseous medium entirely enclosed by said chamber.

3. An acoustic transformer comprising a base; a substantially spherical thin shell connected with the base and forming therewith a gas tight chamber; means for admitting a gaseous medium under pressure into said chamber extending through said base; and a vibratable diaphragm immersed in said gaseous medium entirely enclosed by said chamber.

4. An acoustic transformer comprising a base; a substantially spherical shell of elastic material connected with the base and forming therewith a gas tight chamber; means for admitting a gaseous medium under pressure into said chamber extending through said base; and a vibratable diaphragm imanersed in said gaseous medium entirely enclosed by said chamber.

Signed at Highland Park, 111., this 15th day of November, 1928.

PERCY A. ROBBINS.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2797766 *Oct 20, 1953Jul 2, 1957David Bogen & Company IncLouid speaker
US3302748 *Apr 11, 1963Feb 7, 1967Prentiss B ReedLoudspeaker system
US3310129 *Sep 8, 1964Mar 21, 1967Beehler Vernon DSonar wand
US3378098 *Mar 22, 1966Apr 16, 1968Du PontSystem for improved reproduction of sound
US4183422 *Jan 12, 1978Jan 15, 1980Williams David WUnderwater communications device
US4823907 *May 19, 1987Apr 25, 1989Hatsuo HoshiBalloon assembly
EP1073311A2 *Jul 26, 2000Jan 31, 2001Heiner FitznerLoudspeaker system
WO1979000497A1 *Jan 10, 1979Aug 9, 1979D WilliamsUnderwater communications device
Classifications
U.S. Classification181/153, 181/157
International ClassificationH04R1/00, H04R1/42
Cooperative ClassificationH04R1/42
European ClassificationH04R1/42