US1900489A - Musical instrument of the violin type - Google Patents

Description

March 7, 1933.

G. EISENBERG MUSICAL INSTRUMENT OF THE VIOLIN TYPE Filed April 2, 1929 2 Sheets-Sheet 1 INVENTORS GEORGE EISENBERG mm/M' ATTORNEY March 7, 1933. e. EISENBERG 1,900,489

MUSICAL INSTRUMENT OF THE VIOLIN TYPE Filed April 2, 1929 2 Sheets-Sheet 2 A 54.? an :7

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lNVENTORS GEORGE EISENBERG ATTORNEY Patented Mar. 7, 1933 GEORGE EISENBEEG, F

PATENT OFFICE BROOKLYN, NEW YORK MUSICAL INSTRUMENT 0F THE VIOLIN TYPE Application filed April 2,

This invention relates to musical instruments and has particular reference to an improvement in a stringed instrument of the violin type.

The main object of the invention is to provide a simple and efficient means whereby the bowing of a single stringed instrument of the violin type will result in the re-v production of a volume from such an act of several times the amount of sound which would ordinarily be produced from the single instrument.

A further object is to produce this increased volume of tone with absolute clarity and accuracy as to pitch and timbre of the original tone.

A still further object is to provide a simple, compact device which can be applied to the stringed instrument and can be quickly 20 and easily adjusted by the musician, after which he can proceed to play it without having to give further thought to the device.

Further and more specific objects, features, and advantages will more clearly apar from the detailed description given beow taken in connection with the accompanying drawings, which form part of the s ecification and illustrate one embodiment o the invention, and in which,

Fig. 1 is a plan view of the improved musical instrument,

Fig. 2 is a partial longitudinal sectional view, enlarged, showing the manner in which the electrical unit is mounted on the frame of the instrument,

Fig. 3 is a cross section taken on the line 3-3 of Fig. 2,

Fig. 4 is a section taken on the line 4-4 of Fig. 2,

Fig. 5 is a cross section taken on the line 5-5 of Fig. 2, and,

Fig. 6 is a cross section taken on the line 66 of Fig. 2.

Description of the construction In the preferred form as at present embodied and illustrated in the drawings, the invention is applied to a musical instrument I, of the violin type having a frame 10 provided w th the usual neck 11. The usual 1929. Serial R0. 351,874.

belly and back are lacking and instead the frame 10 is provided with bars 12 and 13 extending from the front to the rear of the frame 10 respectively at the top and the bottom thereof. The upper bar 12 is reinforced with a dependent flange 14 as shown. A cross bar 15 is also provided. The instrumentis provided with the usual strings 16 fastened at one end to the tail piece 17 and passing over the bridge 18 mounted on the upper bar 12.

Fastened rigidly to the top of the bridge by lock nuts 19 and 20 is a rod 21 acting as transmitter of vibrations from the strings 16 through the bridge 18. This rod extends outwardly for a short distance and then downwardly through a hole 22 in the upper bar 12, clearing this hole 22 without contact therewith. At its lower end it is bent outwardly again and extends rearwardly of the frame and its outer end lies freely within a central bore or opening in a magnet coil 23. At the lower portion of the rod 21 Where it bends outwardly, it is engaged by a flexible member such as a cat-gut string or cord 24 which is Wrapped around a shaft 25. The other 75 end of the shaft 25 has a worm wheel 26 meshing with a worm gear 27 on a shaft 28 to the upper end of which is fastened a thumb piece 29 by turning which the tension and position of the vibration member or rod 21 can be regulated through tightening or loosening the cat-gut.

The electrical unit which is affected by the vibrations of the member or rod 21 comprises a horse-shoe magnet 30. Beneath the magnet 30 there is disposed a metallic plate 31 of the same general shape and area. Disposed between this plate 31 and the lower face of the magnet 30 is a sheet of fiber or insulation 32. At its forward edge the plate 31 is provided with upstanding spaced ears 33 and 34 formed integrally therewith, and having a gap therebetween at the center of the forward edge of the plate 31. Disposed back of the ears 33 and 34 are a pair of U- 95 shaped pole pieces 35 and 36 located with their bases facing away from each other and with their respective legs extending toward each other. The legs 37 and 38 of these polo pieces 35 and 36 have parallel faces and are spaced apart a given distance back of the gap formed between the cars 33 and 34 above mentioned. The other legs 39 and 40 of these pole pieces 35 and 36 are tapered and their outer ends are small and lie closely adjacent each other but parallel to form a small gap therebetween much smaller than the gap or distance between the legs 37 and 38. These pole pieces are held in position by means of screws passing through the legs 37 and 38 and headed into a plate 41 of non-magnetic material lying back of the other side of the face of these legs. The other ends of these screws are engaged by lock nuts lying against the opposite faces of the ears 33 and 34. A shield plate 42 of non-magnetic material is held between the lock nuts and in front of the ears 33 and 34. The plate 41 has a hole in its center in line with the gap between the legs 37 and 38 to permit of the passage of the end of the vibrating rod 21. The outer end of this rod will lie very close to the gap between the legs 39 and 40 and because the magnetic field across this gap is very intense the efiect of the vibration of the rod thereon is to make the field variations very sensitive. The horse-shoe magnet 30 is held in position against the pole pieces merely by reason of the magnetic pull. Within the pole pieces, the magnetic coil 23 is disposed and lies snugly therein but is not fastened in place. Wires 43 and 44 leading from the coil 23 are fastened to an insulating block 45 disposed loosely within the horse-shoe magnet back of the coil 23. This block 45 has a central screw which passes through holes in the sheets 32, the plate 31 and the brass container 46 to engage the lower bar 13 and is held by nuts 47 and 48 in position on the bar 13 and within the container 46. A soft pad of rubber 49 lies within the brass container between the ends of the screws connected to the plate 41 and the end wall of the container or box 46. This pad 49 has a hole therein to permit of the passage of the rod 21, and acts as a damper of vibrations.

The wires 50 and 51 connected to terminal clips 52 and 53 on the block 45 pass through a hole in the plate 31 and on their othcr ends are provided with tips to connect to any suitable electrical device such as an audio frequency amplifier.

Operation 0,1 the device When the strings of the instrument are bowed or otherwise vibrated to produce simple melody vibrations or complicated ones representing harmonies, these vibrations are transmitted to the bridge 18. This in turn is set into vibration and these are transmitted to the transmitting member or rod 21. The sensitivity of this red 21 to being vibrated is to some extent dependent upon the tension set up therein by the adjustment through the intermediary of the cat-gut flexible member 24 which can be adjusted in the manner above described. This adjustment also positions the rod with respect to the magnet pole pieces.

The magnetic field into which the end of the rod 21 extends is strong but is particularly so near the outer end of the rod 21 and between the legs 39 and 40 where the field is very concentrated and the slightest vibration of the end of the rod 21 closely adjacent to the gap between these two legs causes a strong and very sensitive variation in the magnetic field which sets up, in the usual manner strong and very sensitive variations in the current in the coil 23 which are sent out over the wires 50 and 51 to the audioamplifier and properly magnified to be reproduced on a loud speaker or other device. Thus the vibration of the strings 16 can be strongly and with extreme accuracy amplified so that the resultant volume is equal to that of several stringed instruments instead of to one. By utilizing this arrangement, a small orchestra of stringed instruments can be amplified to equal a much larger one.

In other words, the stringed instruments not only generate air vibrations as usual but set up very strong and sensitive electrical vibrations which are amplified many times if desired. Several instrmnents can be connected up to the same audio amplifier so that one loud-speaker can send forth the combined instrumental effects of the several instruments.

It is to be distinctly understood that when we speak of stringed instruments of the violin type we mean to include such instruments as Violas, cellos, bass viols, mandolins, banjos, and other stringedinstruments.

The device is simple, compact. and can be readily adjusted so that the utmost sensitivity of the vibratory parts can be obtained without any trouble on the part. of the musician. When the vibrator has once been adjusted, the musician plays as usual and has nothing further to concern him except his playing.

While 1 have described our improvement in detail and with respect to a preferred form thereof, I do not desire to be limited to such details or form since many changes and modifications may be made and the invention embodied in other forms Without departing from the spirit and scope of the invention in its broader aspects. Hence I desire to cover all modifications and forms coming within the language or scope of any one or more of the appended claims.

V7 hat I claim as new and useful, and dcsire to secure by Letters Patent, is,

1. A musical instrument of the violin type having a string and a bridge connected thereto, a magnetic unit mounted on the instrument, pole pieces on said unit having a pinrality of gaps of different span, a vibratory armature extending between one gap and lying closely adjacent a snialler gap at its out er end, and means connecting the armature to the bridge.

2. A musical instrument of the violin type having a string and a bridge connected thereto, a magnetic unit mounted on the instrument, pole pieces on said unit havin a plurality of gaps of different span, a vi ratory armature extending between one gap and lying closely adjacent a smaller gap at its outer end, means connecting the armature to the bridge, and means to adjust the armature with respect to one of the gaps.

3. A musical instrument of the type described, comprising a string to be vibrated, an electrical unit having a magnetic field and mounted on said instrument, means to transmit the vibration of the string to the unit and translate them into electrical current variations therein, and means to independently adjust the vibration transmitting means to regulate the sensitivity of the device.

4. A musical instrument of the violin type comprising a string to be vibrated, an elect-rical unit having a magnetic field and mounted on said instrument, an armature lying in said magnetic field and responsive to the vibration of said string, and means to independently adjust the armature and regulate the sensitivity of the device.

5. A musical instrument of the violin type comprising a string to be vibrated, an electrical unit having a magnetic field and mounted on said instrument, an armature lying in said magnetic field and responsive to the vibrations of said string, and means connected to said armature intermediate its length between the electrical unit and the string to adjust the tension in the armature and regulate the sensitivity of the device.

(3. A musical instrument of the violin type comprising a string to be vibrated, a bridge on the violin supporting said string, an electrical unit having a magnetic field and mounted on said instrument, an armature having a portion lying in said magnetic field and extending therefrom and connected directly to said bridge, and adjustable means connected to said armature intermediate the electrical unit and said bridge to place the armature under variable tension to regulate the sensitivity of the device.

In testimony that I claim the invention above set forth, I afiix my signature hereto.

GEORGE EISENBERG.

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