US1525320A - Amblifying horn - Google Patents

Description

Feb.3,'1925. 1,525,320

W. PIERCE AMPLIFYING HORN Filed March lo, 192.2

l l l l imma H pliyingk Horns; and I do hereby declare the Patented Feb. 3, 1925.."l y

` 'UNITED STATES wmnmm rumen, or ALLnNrowN, rnNNsYLvANIA. y

AMBLIFYING HORN.

Application led March 10, 1922. Serial No. 542,707.

To all whom z't'mag/ concern:

Be it known that I, WILHELII Pinnen, of Allentown, inthe county of Lehigh and State of Pennsylvania, have invented certain new and useful Improvements in Amollowing to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it appe'rtains to make and usethe same.

My invention relates to graphophones and particularly to the means employed for amplifying the sound, the object of my invention being to prodae a simple `and eilicient amplifying horn a -apted to be located within a cabinet beneath the reproducing mechanism, and embodying an elongated enclosed tortuous passageway for the lsound of gradually expanding area, the side walls of which are so arranged as to obviate all echo and to insure a mellowed enlargement of the tones.

In the drawings, Figure 1 is a perspective of the'ampliying horn removed from the cabinet and looking from above. Figure 2 is a cross sectional view., Figure 3 is a verticalv sectional viewtaken through the center of the horn from front to rear, 0n the line 3-8, Figure 2.

My improved amplii'er includes, in the main, what I shall term two portions, the throat portion 1 and the mouth portion 2.

lIn the manufacture of my improved amplitying horn I preferably employ wood so as tr secure mellowness of tone and this necessitates the forming of the throat portion 1 as a separate element from the mouth portion 2, these portions being united, as at 3, in a manner to insure rigidity and prevent any vibration between the portions which might effect the quality ofl the'tone transmitted. The throat portion 1 at its upper extremity connects with the outlet of the frontl and rear' undulating walls 6.

tone arm (not shown) of the graphophone andncludes two downwardly extending sides 4 and 5 formed of straight cut strips 'zpld e sides 4 and 5 and the walls 6 spread graduallyr from the point of connection with the tone arm so that at the union with the mouth l piece the cro sectional area of the passageway defined by the throat portion is larger than its cross sectional area at its upper end. The mouth portion 12 ofthe amplifier comprises bottomand top Walls 9 and 10, the former, by preference, being perfectly flat,

and spaced diverging sides 12 and 13. Each of the sides 12 and 13 from Athe point a to point b describes a volute curve, 'the curvature of leach being'such that passageway between them is of graduniy increasing width. From the point' 'fi to point c the side 13 is approximately straight with its extremity outwardly flared. Side 12 between the points d and e describes a double curve, and the height of each of the sides .12 and 13 is gradually increased adjacent the mouthV of the horn, this being eiected by a sloping of the upper edge of each side so as to support the flared end of the top y,wall 10. The' undulating passageway from enlargement of the passageway at the mouth' of the horn is productive of a transmission of sound from the tone arm. with ampliied and unmarred clearness such as is not obtainable in the use of known devices for magnifying the reproduction of sound.

The central location lof the'reduced inlet of the mouth portion 2 is especially 'advantageous since it permits the sound to enter the same at a substantial distance from the walls of the phonograph cabinet thus preventing any sound Waves from reaching said walls withl suicient force to be heard therethrough.A The purpose of the undulatory diverging throat walls 6 is to render the ysound Waves clear and sonorous during the downward passage of the same into the reduced centrally located inlet of the mouth 2, while thevolutely curving portion thereof ofV gradual` increasing cro sectional area sweetens and softens the sound permitting it to gradually expand and rise with the increasing height of the walls 12 and l13 r to eminate through the flared portion of the mouth.-

Particular attention is directed to the fact that the convolute formation of the mouth portion-of the horn defines what might be said tobeha substantially centrally arranged opening for the reception of the lower portlon of the throat 'member v1. The lower end ofthe throat member 1 is extended into and is ri `dly secured in the inlet end of the mout portion and a .sound proof joint or connection is maintained between the throat and mouth portions during the use of the phonograph equipped with the horn.

Therefore, if the phonograph isfhandled case or while. in use the sound proof joint between the throat and mouth portions is not in any way disturbed' and if during the use of the phonograph dancers or persons standi about the phonographs should aooidentlaiy bump against the same the sound proof joint between the throat and mouth portions will be undisturbed. This is possible because' the convo-lute formation of the mouth portion imparts ak certain degree of elasticity to vthe horn so that the horn is enabled to absorb shocks.

I' claim as my invention An amplifying horn comprising a mouth -1,525,3220 e V l portion of oonvolute formation having an inlet end, the' convolute formation of the mouth portion deining asubstantially oentrally locatedyopening, and a throat portion extended into said centrallylooated opening and having its lower end extended into and rigidly secured in the inlet end of said mouth portion, said mouth portion having diverging side wallsinereasing in height toward the outlet end of the horn.

- In testimony whereof I have signed this specification.

WILHELM PIERCE.

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