US1571378A

US1571378A - Sound-reproducing arrangement

Info

Publication number: US1571378A
Application number: US670223A
Authority: US
Inventors: Schloemilch Wilhelm
Original assignee: Telefunken Gesellschaft fuer Drahtlose Telegraphie mbH
Current assignee: Telefunken AG
Priority date: 1923-10-23
Filing date: 1923-10-23
Publication date: 1926-02-02
Anticipated expiration: 1943-02-02

Description

Feb. 2', 1926.

W. SCHLOEMILCH SOUND REPRODUCING ARRANGEMENT Filed Oct. 23

Patented Pet. 2, 61926. n

UNITED. STATES PATENT OF WILHELM SCHLOEMILOE, on BERLIN, ERMANY, nssrenon 'ro ensnnnscm'r run I DBAHTLOSE TELEGBAIPHIE 111.13. 11., OF BERL GERMANY.

' sounn-nnrnonucme nnnane nmnnr.

Application filed cameras, 19%. Serial no. 670,223. J

i To all whom it may concern: a

leading fro IN, GERMANY, n conronnrronor m'the source of air (not shown).

Be 'known that I, WILHELM SCHLOE- The pipe L leads into the air chamber W. MInoH, a citizen of Germany, and aw Leading from the air'chamber W is a fleze resident of Hallesches Ufer 12713, -Ber ible air conduit O,which leads to the resolin, S. .V W. 11, Germany, have 'invent ed new and useful. Improvements in Sound-Reproducing Arrangements, of which the following is a specification, ac-- companied by drawings.

The invention relates to a loud speaker which-differs from those heretofore known in so far as instead of a membrane, an elastic body which has no natural vibration- 1S 9 1 Many attempts have been made touse the electro-mechanical movements produced by speech-current for controllin the yelocity of an issuing gas-current or vapour-current by valves orthe like and for producing loud speech in this way. All these former attempts failed, because it was not possible to construct the proposed valves or throttlevalves of such a small mass as to enable them "to follow the very quick oscillations copres ipndin'g to the-highest harmonics.

Anot erv disadvantage of all these arrangements was that the current pf air passing hard and sharp edges or curves produced a whistling sound and that the graduation of sound became too coarse and hard. p

In contrast with these devices, the present inventionvimitates the mechanism of the human larynx't'o a certain degree. The exhaust of a current of air is controlled by a1 tering the diameter of a flexible -'r conduit made of caoutchouc or other s1 ilar soft material in a mechanical or electro-magnetic far as to-p'rovide 5c the exhaust end ofthe flexible air conduit, a chamber which is half or less open and resonant to the means frequency of the sound. 7

The invention is schematically represented in the accompanying drawing.

The terminals of the winding of an electromagnet having a coresM and armature S are denoted by aand'b; denotes a pipe nating chamber R corresponding to the hu-' 'man oral cavity. Leading out of the cham ber R is the horn T for delivering the sound.

It will be noted that the flexible conduit 0 passes between the stationary and a d-. justable anchor member 13 and the armature S. The walls of the flexible conduit 0 are pressed and slightly flattened between said anchor member S and armature S as shown in the drawmg. When an electric current 1n the'form of sound variations is impressed upon the terminals as, b of the winding of the electromagnet, armature Swill be caused to vibrate according to said sound variations.

sound variations.

. The. variations in cross-sectional area ofthe conduit 0 will cause the air flowing through the conduit to vary. These varia-.

tions will be resonated in chamber Band will be delivered through the horn T.

It is possible to form an acoustic amplifier-c'ascade in a suitable way, with several of such apparatuses by using the alteration of one arrangement for controlling the next.

Having described my invention, what I claim is:

. 1. A 'sound reproducing arrangement comprising a flexible as conduit and means a for. electromagnetica y altering the crosssectional areaof the conduit in acpordancc with sound waves.

2;. An acoustic arrangement comprising, a

" flexible gas conduit, a device engagmga'nd flattening said conduit at a point along its length, and means for controlling'said device whereby the wall of said conduit is'caused to flex in accordance with sound variations.

3. A" sound reproducing arrangement I ,comprisinga' flexible gas conduit, a device arranged to flatten the conduit at a point along its length, and means for operating said device in accordance with sound waves to vary the cross-sectional area of the co duit at said point.

- 4. A sound re roducing arrangement comon the exhaust side of said resonant to the mean 15 .duit at a point device arran tten the conduit at a point along its length, and means for electromagnetl'cally operating said device in accordance with sound waves.- r

5. A sound reproducing arrangement comprising a flexible gas conduit, a control ling device arran d to flatten the gas cona ong its length, means for electromagnetically operating said device in accordance with sound waves, and achamberconduit which is frequency of the arrangement comexible gas conduit sound waves. r

' 6. A sound reproduc' prising gas chamber,a

connected with the outlet of said chamber,

a'controllingdeviee arranged to flatten the gas conduit at a point" along itslength, means .for. electromagnetically operating. said device in accordance with sound waves, and a chamber on theexhaust side of said conduit which is resonant to the mean frequency. of the sound waves. 1 -7. An'acoustic arrangement comprising, a flexible gas conduit, an anchor member-engaging said conduit at. a point along its I length, an electromagnet having a windin and armature, said armature engaging sai conduit on the opposite side thereof from said member, said conduit being pressed between said armature and said member and its walls flexing in accordance with electric sound waves impressed on said winding.