US 846068 A
Description (OCR text may contain errors)
PATENTED MAR. 5, 1907.
K. M. TURNER & N. W. JOHNSTON.
APPLICATION FILED AUG-25. 1905.
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KELLEY M. TURNER, OF N EW YORK, NORTON JOHNSTON, OFT CHAP- PAQUA, NEW YORK, ASSIGNORS, BY MESNE ASSIGNMENTS, 'TO GENERAL ACOUSTIC COMPANY, A CORPORATION OF NEW YORK.
Specification of Letters Patent.
Patented March 5,1907.
Application and August 25, 1905. Serial No. 275.762.
To all whom it may concern:
Be it known that we, KELLEY M. TURNER, of'the city, county, and State of New York, and NoRTonW. JoHNsroN, of Chappaqua, Westchester county, New York, have invented certain' new and useful Improvemerits in Acousticons, of which the following is a full, clear, and exact description.
Our invention relates to telephonic trans- I0 mitting appliances.
In a patent to M. R. Hutehison, No. 737,242, there is described an apparatus by which any number of deaf persons within an assembly or gathering may hear all that is going on andtake part in the conversation.
The apparatus comprises, essentially, a transmitting device, known as an acousticon, which is placed at a central position in the room and connected to circuits including tele- "'eo phone-receivers for the various deaf persons.
The object of the present invention is to 3 improve and perfect the above-described transmitting apparatus or acousticon and to -render it at once more simple of construction, 5 'moreefhclent in operation, and more pleasin in appearance.
. ith these andother objects in view our invention consists in the construction, combination, location, and arrangement of parts, all as will be more fully hereinafter set forth, as shown in the accompanying drawing, and finally particularly pointed out in the appended claim.
In the drawings, Figure 1 is a perspective view of an acousticon embodying the principles of our invention, and Fig. 2 is a diagram showing the manner in which sound-waves are received by the acoustieon.
It is evident that an instrument of this character must be adapted to receive the sounds in a substantially equal way from every direction that they are likely tocome. In practice the sounds of conversation from a group of persons emanate from points around a circle or circumference, but generally lie in the same horizontal plane, so that the sound may be considered as coming uniformly from all points in the periphery of a horizontal circular plane surface ordinarily about four or five feet above the floor. The
acousticon which We have provided is adapted to receive the sounds in the most efficient and uniform way.
Referring now to thedrawing, and to the various views and reference-signs appearing thereon, inwhich like parts are designated by the same reference-sign wherever they occur, 1 denotes a base or casing for a battery, which constitutes the supporting-frame of the instrument and is preferably in the form of a square prismatic box, which may have a drawer therein provided with any suitable clasps 3, by which it may be held in position. Upon the base or block 1 we erect a prismatic structure 4, having a certain-fixed and definite arrangement of faces, in which are inset the acousticon-transmitters proper.
5 denotes a handle upon the top piece of the prismatic structure, by which the instrument may be carried about, and 6 indicates terminal blocks at a convenient point, by which the connection may be made to the various telephonic receivers.
We have discovered that the efficiency of the aeousticon varies widely according to the shape of the prismatic structure 4. A simple consideration will show that no two sound-waves are likely to strike the instrument in exactly the same way, one, for example, striking a face squarely and another striking it at a greater or less angle. course intolerable in practice to have the sound from one section received much more clearly than from another, since under such circumstances it would be impossible to adjust'the receivers for any one person without )utting them out of adjustment for another. n acousticon should therefore be made in such a Way as to receive the sounds uniformly from every direction. This may be accomplished by making it with a very large number of faces, in which case it would have a substantially equal effect in all directions; but we have discovered a shape by which the acousticon attains remarkable eliicicncy and in the simplest and most convenient manner.
We have discovered that by making the prismatic structure in the form of a threesided equilateral triangular prism that a remarkable efficiency is attained, and in Fig. 2 of the drawing we have indicated the shape of the prism used in order to show the reason for the high ellicieney attained. Each of the sides I) of the equilateral triangle A may be considered to be a face of the prism. It is evident that a sou nd-wave, such as S, strikes It is of ICC i an area of the acousticon-surface which is width of the face.
never greater than the side I) and varies between this amount and a value proportionalto the altitude of the triangle A, or, in other words, IIIXJZ, which equals .866//.
bXMfZ, or 1.514, when the sound strikes theacousticon at one of its corners. Accordingly the diflerence between maximum and minimum efiiciency for a square and for a triangi'llar acousticon is substantially four times as greatin the case of the square as in the case of the triangular instrument. As a matter of fact, it is greater than this in prac-' tice on account of the fact that the transmitters employed in the acousticon are circular and have a diameter determined by the The real efficiency is therefore proportional to the area of the circular transmitters and to the squares of the figures above given.
7 denotes the transmitters within the faces of the acousticon, and in practice we prefer to secure' two transmitters within each face. These transmitters are connected together into one or more electrical circuits including the receivers above mentioned in a manner By the use of our invention an acousticon 'of maximum efficiency is produced, and in addition it is evident that by the use of three faces a much simpler construction is provided than would be true of a greater number. Moreover, the triangular form employed gives individual faces which are wider than would be possible of any other polygonal shape, so thatlarger transmitters may be used in the faces and a greater area and efficiency secured than in another form. It is also evident that the completed structure is much more pleasing in appearance by virtue of its triangular form than would be true of arectang'ular structure, which looks like a mere box and has nothing about it which is pleasing in appearance or which would attract the eye.
What we claim is- I In a telephonic transmitting apparatus, a base or box adapted to contain an'electric battery, a prismatic structure erected pen and supported by said base or box,'said structure having an equilateral triangular form with three symmetrical faces, a trans:
mitter inset into each, of said faces,and electrical connections including said battery and said transmitters adapted to be connected to, a suitable receiver. l
In witness whereof we subscribe our sigf natures in the presence of two witnesses.
KELLEY M. TURNER.
NORTON W. JOHNSTQN'.
FRANK S. OBEn,
ALFRED W. PRocToR.