US1181146A - Apparatus for transmitting sound-waves. - Google Patents

Description

E. A. LEET.

APPARATUS FOR TRANSMITTING SOUND WAVES.

APPLICATION FILED SEPT.26, I9I2. RENEWED SEPT. 25, 1915.

Patented May 2, 1916.

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E. A. LEET.

APPARATUS FOR TRANSMITTING SOUND WAVES.

APPLICATION FILED SEPT.26, I912- RENEWED SEPT. 25. 1915.

1 1 8 1 1 46. Patented May 2, 1916.

2 SHEETSSHEET 2.

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j? n I EDWARD ALLEN LEET, OF NEW YORK, N. Y.

APPARATUS FOR TRANSMITTING SOUND-WAVES.

Specification of Letters Patent.

Patented May 2, 1916.

Application filed September 26, 1912, Serial No. 722,490. Renewed September 25, 1915. Serial No. 52,705.

To all whom it may concern.-

Be it known that I, EDWARD ALLEN LEET, a citizen of the United States, residing at New York city, in the county and State of New York, have invented certain new and useful Improvements in Apparatus for Transmitting SOUHCl- RYGS, of which the following is a specification.

My invention relates to a method of and apparatus for transmitting sound waves, and the object of my invention is a device through which sound waves may be transmitted from the sound box to the delivery end of the device without being modified by secondary vibrations set up in the walls or body of the device through which the original vibrations are transmitted.

It is a well known fact that sound waves transmitted through a horn are materially modified by secondary vibrations set up in the walls of the horn or body of the device, and I have observed that where the walls of the horn are made of a suitable material and sufliciently heavy so as to in effect cushion the sound wave but not set up secondary vibrations, that the sounds delivered from the device will be clear and mellow in tone and entirely free from all sounds due to vibrations not originating in the sound box.

I will describe my invention as applied to a phonograph, where the sounds transmitted are amplified. I wish it understood, however, that the same system may be used for concentrating sounds when transmitted to a recording instrument.

The accompanying drawings will serve to illustrate my invention, in which Figure 1 is a plan viewand partial horizontal section; Fig. 2 a section taken on the line II of Fig. 1; Fig. 3 a section taken on the line III of Fig. 1.

In the drawings, 5 represents a case. This case consists of a bottom 6, a top 7, straight side walls 8, 9 and 10, and curved wall 11. The walls 8 and 9 are joined at 12; 9 and 10 at 13; 8 and 11 at 14; 9 and 11 at 15. By reason of the wall 11, the interior of the case is divided into two spaces, 2'. 6.. the space A in which the usual mechanism M for driving the phonographic record is situated, and the space B, which forms part of the sound passage. Mounted upon the top of the case is a circular plate P, adapted to carry a phonographic record B. One side of the case is provided with doors D which may be opened and closed. The space B has a top wall 16,

and a bottom wall 17. One end of the walls 9 and 10 and top and bottom walls 16 and 17, is carried upward to form a projecting portion 18, provided with a concave seat 19 in which is located the lower end '20 of a tube 21. 22 indicates a retaining plate. The concave seat 19, end 20 and retaining plate 22, constitute a ball socket joint. Connected to the opposite end of the tube 21 is a sound box 23, and secured in the sound box is the usual needle or device 24 adapted to pass over the phonographic record R and communicate the vibrations to the sound box, thence from the sound box through the sound passage B to the atmosphere from the outer and larger end of the sound chamher.

It will be observed that the sound passage B is small at the end 25, and large at the end 26. I do not limit myself to the precise shape of the sound passage indicated, as it may be varied in accordance with the general configuration of the case 5.

In constructing the walls of the sound passage, I prefer this should be made of material such as wood, which will be slightly resilient to the impact of the sound waves, but su'fiiciently thick and heavy to prevent the impact of the sound waves setting up vibrations in the walls of the sound passage. In the drawings I have indicated the walls of the sound passage as of considerable thickness. By experience I have found that the best results are obtained when the sound passage is carved out of a solid block of wood. This block, however, may be built up by gluing or otherwise fastening separate blocks of wood together. I do not limit myself to the use of wood, providing the material employed is, as before stated, slightly resilient to the impact of the sound waves. By experiment I have found that if the walls of the sound passage are slightly resilient, the sounds transmitted are mellow in tone, whereas if the walls are not resilient the sounds are sharp and harsh. So far as I can discover, resiliency in the walls has the effect of producing an intermingling of the original sound vibrations, at least to a sufficient extent to prevent individual vibrations from being separately distinguished in the emitted sounds.

hat I wish to have understood as the es sence of my invention is, I believe I am the first to recognize the fact that to produce mellowness and pureness of tone, it is essential that the original sound Waves be transmitted through a passage formed of material Which shall be slightly resilient to the sound Waves, but which will not be aflected by the sound Waves to set up secondary vibrations, or in other Words, that I am the first to produce an instrument which will transmit the original sound Waves and deliver them modified only by the cushioning effect of the Walls of the sound passage.

Having thus described my invention, I claim:-

1. In apparatus for transmitting sound Waves, a sound conduit in two sections, one movable relatively to the other, both sections having Walls of Wood at least one-half inch in thickness throughout their lengths, Whereby they are capable of, cushioning the original sound vibrations without setting up secondary vibrations in their structure.

2. In apparatus for transmitting sound Waves, the combination with a sound box, of a complete transmitting and amplifying passage extending from the sound box and having throughout its entire length Walls of Wood at least one-half inch in thickness, whereby the original sound vibrations are not modified by secondary vibrations set up in the structure of said Walls.

In testimony whereof, I affix my signature in the presence of two Witnesses,

EDWVARD ALLEN LEET.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner 0!, Patents,

Washington, D. C.

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