US1510476A - Tone-amplifying apparatus for musical instruments - Google Patents

Description

Oct. 7 1924. 1,510,476

F. c. HAMMOND TONE AMPLIFYING APPARATUS FOR MUSICAL INSTRUMENTS Original Filed July 8, 1922 0 74 f 5 z w r1 11 ATTERY- 1 ,2

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' UNITEDFSTA FRED C. HAIIOND, 01' CHABLESTOWN, NEW EAIQSE IBE, ASSIGNOROI ONE-HALF r wanna w. snacx, or sramermnn, vmmonr.

roflmmrmo arr'uwrus roa MUSICAL msraunnn'ra Application filed July 3,1922, Serial no. traces. lenewed rebmar a7, 1924.

To all whom it may concern.- Be it known that I, Fnnn C. HAMMOND, a

.citizen of the United States, residing at Gharlestown, in the count of Sullivan-and State of New, Hampshire, ave inventednew and-useful Improvements in Tone-Amplify ing Apparatus for Musical- Instruments, of

which the following is a specification.

: vice.

,trating a difierent arrangement.

Thisinventiomrelates to means'for amplifying the toneg of a musical instrument having a resonant element, such as the body of a violin, violincello, viola, banjo, guitar, or mandolin, or the sound board of a harp or iano, the amplification being capable of i-ng instantly changed by a leader or director, while the instrument is being played bya performer, to vary the volume of tone coming from the instrument.

An object of'the invention is to provide a suitable device associated with the resonant element of the instrument, and connected with suitable electrical amplifying means, which is in turn connected with a receiver or loud speaker, whereby a. director may vary the volume of tone of an instrument, or any number of instruments.

A further object of the invention isto provide a musical instrument which includes a sound post, such as'that of a violin, etc.,'and .a microphone associated with the sound post, and electrically connected with one or more stages of amplification, and in turnconnected with a receiver or loud speaker.

Other objects will appear as the description proceeds. Y

' Of the accompanyingdrawings forming a part of this specification,

Figure 1 is a plan view of a violin showing the position of the microphone-carrying sound Post. 1

Figure '2 is a longitudinal section of a ,violin, showing the microphone-carrying sound post in position between the front and back of the violin. I

Figure 3' is a diagrammatic view, illus trating asuitable arrangement of the wiring of the circuits for the tone-amplifying de- Figure 4 is a diagrammatic view illus-' Figure 5 is. a diagrammatic view, illustrating anotherarrangement.

Like characters .of reference are used throughout the following specification, to designate like parts.

' the volume of music coming adapting my invention to a violin, or similar instrument, which includes a 'resonant body 1, and a sound post 2, I preferably provide the sound post with an enlarged connection'on the microphone. This circuit is called the primary circuit, and collects the tone vibrations when the instrument is played.

" I The secondary circuit commences with one side of the secondary ofthe coil 8, and connectswith the grid 9 of an amplifier 01 audion bulb 1O. The plate 11 of the bulb 10 connects with the positive side ofthe B battery, which is preferably approximately twenty-two volts. The negative side of the B battery connects to one post. of a loud speaking receiver 12, and from thence to the post 13, and back to the opposite end of the secondary of the coil 8.

A third circuit connects the negative pole.

of a six-volt A or lighting battery with the pole 13, and from thence to one side of the filament 14. The other side of the filament connects with the arm 15 of the rheostat 16,

and from thence back to the A battery. From the foregoing description, it will be seen that the sound waves from the instrument will be picked up by thernicrophone, and will be induced from the primary of the coil to the secondary of the coil. The amplifier bulb .10 Will amplify the waves many times, until they are collected by the receiver 12, which also amplifies'the volume. It will be' apparent that as many steps of amplification may be used as desired, so that an orchestra director may readily change from the instruments equipped with this apparatus, to suitthe requirements of the musical number being played. i

The principle involved in this device is much similar to that of the wireless telethe positive side of phone, wherein the loudness of the signals I such installation is complete, an orchestra director will have the highest degree of control over his orchestra, and may modify the tone of each instrument independently of the player.

In applying my invention to a musical instrument which does not include a sound post, and includes a resonant element, such as the soundboard of a piano, the microphone may be secured in any suitableway to the resonant element, care being taken to prevent dampening of the vibrations. It will be understood that many minor changes in details and arrangement may be resorted to without departing from the spirit'of the invention. For example, the arrangement shown diagrammatically by Figure 4 may be employed. This arrangement dispenses with the dry cells 7, and switches off the current automatically when the filament is cut off.

The arrangement shown diagrammatically by Figure 5, materially reduces the noises from a violin or similar instrument, caused by movements of the players hand, and the scratching of the bow. This arrangement includes a three point switch 20, adapted to cut out amplification to any extent desired. In experimenting with apparatus, including the arrangement shown by Figure 5, l have attached the first tube plate to the third, with great improvement in the quality and volume of tone.

The invention may be adapted to wind rai er/e instrument, the shape and material of the instrument giving the tone quality peculiar to the instrument, whether it be of brass or wood. The vibrating air leaves the bell in cone form, and is applied directly to a microphone supported by any suitable means in the path of the vibrating air, the vibrations passing through the amplifying'tub-es to any extent desired. The amplified tones blend with those of the instrument.

I claim:

1. A device of the character described comprising a sound post for an instrument of the violin type, provided with an enlarged hollowed out central portion adapted to receive and house a microphone, in combination with means for amplifying the microphone current.

2. A sound post for an instrument of the violin type, provided with an enlarged hollowed out central portion, a microphone adapted to seat therein, and an electrical amplifying circuit for said microphone.

3. A sound post for an instrument of the violin type, provided with an enlarged hollowed out central portion, a miorophone adapted to seat therein, and an electrical amplifying circuit including a loud speakingunit for said microphone.

In testimony whereof Ihave afiixed my signature.

FRED C. HAWOND.

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