US2027073A - Electricity-controlled musical instrument - Google Patents

Description

1935- o. VIERLING 2,027,023

ELECTRICITY CONTROLLED MUSICAL INSTRUMENT Original Filed Oct. 29, 1951 CURRENT INVENTOR=- 05/745 WISH/WE,

ATTOR Y. I

Patented Jan. 7, 1936 UNITED STATES PATENT OFFICE ELECTRICITY-CONTROLLED MUSICAL INSTRUMENT Oskar Vierling, Berlin, Germany, assignor to Miessner Inventions, Inc., a corporation of New oersey Original application October 29, 1931, Serial No. 571,824. Divided and this application May 12, 111,233. 81.31281 No. 670,761., In Germany Novem- 14 Claims. (Cl. 84-1) My invention relates to electricity-controlled of an electron discharge tube having a cathode musical instruments and more particularly to 6, a grid 1 and an anode 8. The cathode is eninstruments of the kind in which a mechanically ergized by any suitable and well-known means actuated oscillator or tuned vibrator, such as for (not shown). The anode circuit contains in se- 5 instance a string, influences by induction an elecries a loudspeaker 9 and the battery B. 5 tric circuit so that alternating currents of a fre- When the string I is struck by the hammer lh quency corresponding to the frequency of the osit will oscillate initially in the plane A-B with cillator are produced in the circuit, the current relatively large amplitude. After some time, being fed, directly or indirectly, to a loudspeaker however, the string will not oscillate any more 10 or the like. This application is a division of my in the plane A-B, but in such manner that the 10 co-pending application, Serial Number 571',824, section of the string shown in the figure describes filed October 29, 1931, now PatentNo. 1,933,299, a curve, for instance an ellipse E, or a circle or granted October 31, 1933. the like, but even the position of this ellipse may In instruments of the type described it is frenot be fixed unless means, described hereinafter, quently desirable to reduce the momentary h gh are provided fo t pu p l amplitude of the tone at its inception, and the Now obviously the oscillating string will inamplitude of incidental sounds accompanying the duce in the winding 2| an alternating current of tone inception. In the case of a string percusa frequency corresponding to the oscillating fresively excited such incidental sounds may comquency of the string. This current is amplified prise the sound of the hammer touching or hitby the tube 5 and fed to the loudspeaker 9, which 20 ting the string; and such sounds are hereinafter of course produces a sound or tone correspondgenerally referred to as touch noise. It is an ing to the current. A typical current wave as object of my invention to provide means for reinduced in winding ii is shown in' Fig. 2. A ducing the touch noise and the tendency of the current is merely induced by that component of 5 tone intensity to decrease rapidly after the touch. the string oscillation which is normal to the pole 2 According to my invention this is accomplished piece 19 of the magnet l8. Therefore the cur- ,by arranging or shaping the parts of' the electric rent induced in the winding 2! has its maximum circuits influenced by the mechanical oscillators at the beginning of the oscillation of the string in such manner that the initial oscillations of I, when the string oscillates with a relatively large the oscillator are not or are poorly reproduced by amplitude in the plane AB. When the oscil- 30 the electric circuit. lations of the string change over to the elliptical Other objects and advantages of my'invention form the effective component of the string oscilwill become apparent from the following descriplations rapidly decreases, so that a current wave tion in connection with the accompanying drawas shown by the curve 1' in Figure 2 is obtained. 3 ing. In the latter' a are the envelopes of the curve, showing clearly Fig. 1 is a schematic diagram of one embodithe rapid decrease of the intensity after the bement of my invention as applied to a single ginning of the oscillation. Obviously the appastring; ratus thus far described fully produces the touch Figs. 2 and 3 arecurves illustrating the prinnoise, and the tones have the character of a. 40 ciple of operation of my invention; piano tone, the intensity of which drops relatlve- 40 Fig. 4 is a schematic diagram of another em- 1y quickly. bodiment of my invention as applied to a group The pole piece I9 has preferably a--length at of strings such as those of a piano; and least equal to the greater axis of the ellipse E. Fig. 5 is a perspective and schematic diagram For the production of a tone in which the touch of a still further embodiment of my invention as noise is absent, and the intensity of which does -15 applied to a single string. not initially rapidly decrease but may even initi- Referring now to the drawing and first to Fig. l, ally increase gradually, a similar magnet but with I is the cross section of the string of an instruits pole piece arranged parallel to the plane A-B ment, for instance a piano or a violin, which is may be provided. Thus there will be seen in actuated for example by a hammer lh adapted Fig. 1 magnet IS with pole piece I! so arranged, .30 to strike the string and to excite initial vibra-' and carrying coil 20. The initial oscillations of tion thereof in the plane indicated by A-B. t8 the string will not induce a current in the windis a magnet having pole l9 arranged normal to ing 20, since the plane of these oscillations is the plane A-B, and carrying winding 2|. This parallel to the pole piece IT. A current will be winding is connected to the input terminals 4 induced only after the oscillations have changed 5 gradually rise from zero to a maximum value and then decrease slowly. Such a current wave is shown in Fig. .3 of the drawing, a figure corresponding to Fig. 2 described above. From Fig. 3 it appears that the current, and hence sound, intensity indicated by the envelopes a increases from zero to a maximum value and then decreases slowly.

In Fig. 1 the coils 2| and 20 are connected inseries and to the input terminals 4 of the electron tube 5. 2t and 20' are adjustable high ohmic resistances connected in parallel to the coils 2| and 20, respectively. By adjusting these resistances in a suitable manner the ratio of the effects produced by the components of the string oscillations respectively parallel and normal to the plane A-B can be changed in any desired manner, for instance so as to eliminate the touch noise or not. Obviously a net current wave may be obtained of any form between the extremes represented respectively by Figs. 2 and 3.

Any particular intermediate form of current wave may be obtained by employing a'single magnet with pole piece suitably inclined to the plane A-B in which the string oscillates directly after the stroke of the hammer. This arrangement has been shown in Fig. 4, wherein further a use of my invention as applied to a piano is diagrammatically shown. In instruments of this type the touch noise does not'show particularly in the bass, but is very sharp and troublesome in the treble. Therefore in the bass the pole pieces of the magnets are preferably arranged with little or no inclination relative to the string, so that even the initial'oscillation of the string is reproduced, inasmuch as otherwise the bass notes would lose much of their intensity. For the mid notes the magnets are preferably arranged with gradually inclined pole pieces. The magnets of the treble are arranged on one side of the plane of initial oscillation-to wit, the plane determined by the string and hammer. This progressive arrangement is shown in the figure, wherein each magnet is designated as 2, with pole piece I!) and winding 3. Each winding is shown connected to amplifier input terminals 4, which may or may not be common to the several wind-' ings, as desired.

With the arrangement shown in Fig. 4 the treble notes are produced in a considerably softer.

manner than in pianos of the well-known type in which the sounds are produced by means of a sound board. The relative intensity of the bass and treble notes is changed so that bass notes comes forth with relatively greater intensity than thetreble notes. I have found that many music pieces when played on an instrument as shown in Fig. 4 would give a far better impression.

In the embodiments of my invention hitherto described the mechanical oscillator influences an electric circuit by way of electromagnetic inductioni. e., the oscillations are translated from a mechanical into an electrical form by a translating device operating upon an electromagnetic principle. Alternatively electrostatic induction may be employed-4. e., the mechanico-electric translation may be effected by a device operating upon an electrostatic principle. Thus in Fig. 5 the string l is electrically connected to the input terminal 4 of the grid I of the thermionic discharge tube 5. A metal plate 24 connected to the cathode 6 through a battery 25 is arranged adjacent to the string I. 26 is a resistance inserted between the cathode 6 and the grid 1. The

- over to the elliptical form. The current will now capacity of the condenser formed by the metal plate 24 and the string I is charged to the potential of battery 25, but resistance 26 prevents rapid change of this charge. The capacity is periodically changed when the string oscillates and by 5 virtue of the relative constancy of its charge an alternating voltage .is electrostatically induced across it and appears in the input circuit of the tube 5, is amplified by the latter, and is translated into sound by the loudspeaker 9. 10 I The effects obtained by various positionings or arrangements, with respect to the string, of the surface of plate 24 nearest the string are the same as discussed for the pole pieces of the magnets in connection with Figs. 1 and 4. By way of 15 example I have illustrated the surface of plate 24 in Fig. 5 as inclined to the plane A-B of initial oscillation of the string. As illustrated this plane is a vertical one, the hammer lh moving in such plane to strike the string. 7 20 As mentioned above the position ofthe ellipse E is not necessarily a fixed one, but this ellipse may rotate during the oscillation of the string. The reason for this is that the ends of the string are not tightly fixed but merely rest on a bridge 25 or chevalet. The rotation of the ellipse would result in variations of the reproduced sound which are perceived as beats of the reproduced tone. It is therefore highly desirable to suppress the rotation of the ellipse or at least to eliminate 30 its influence on the current induced in the translating device.

In order to accomplish that I provide means for tightly holding the ends of the string. These I have shown in Fig. 5, but it will be understood 35 that this is by way of convenience in illustration only, as the usefulness of the same'is obviously generic to all embodiments of my invention. In this figure, for instance, the front end of string I is held in semi-circular recesses of 4:

, blocks H and I 2. Instead of thus clamping the limitation thereby, the scope of my invention being rather to be determined in accordance'with the following claims. V p

I claim:- I 1. In a musical instrument, the combination of a mechanical oscillator; exciting means therefor operable to produce oscillation thereof which comprises initially a-component in a single plane only and thereafter components in said plane and 60 in a plane normal thereto; and mechanico-electric translating apparatus having a plurality of surface portions in spaced relationship to said oscillator to be inductively influenced thereby, said portions lying in a plane which is inclined 65 to each of said first mentioned planes.

2. In a musical instrument, the combination of a tuned string and exciting means therefor for producing vibration thereof, said vibration comprising initially a component in a given plane only 70 and thereafter components in said given planev and in a. plane normal thereto; and mechanicoelectric translating apparatus having a plurality of surface portions in spaced relationship to said string to be inductively influenced thereby,'said N portions lying in a plane which is inclined to each of said first mentioned planes.

3. In a musical instrument, the combination of a tuned string and exciting means therefor for producing vibration of each point thereon, said vibration of each point initially comprising oscillation in a straight line and thereafter oscillation in an ellipse; and mechanlco-electric translating apparatus having a plurality of surface portions in spaced relationship to a point on said string to be inductively influenced thereby, said portions lying in a line which intersects but is inclined to said first mentioned line.

4. In a musical instrument, the combination of a tuned string and exciting means therefor for producing vibration of each point thereon, said vibration of each point initially comprising oscillation ina straight line and thereafter oscillation in an ellipse; mechanico-electric translating apparatus having a plurality of surface portions in spaced relationship to a point on said string to be inductively influenced thereby, said portions lying in a line which intersects but is inclined to said first mentioned line; and means connected with and influencing the extremities of said string for maintaining substantially fixed the axes of said ellipse of oscillation of said'point.

5. In a musical instrument, the combination of a tuned string; exciting means therefor adapted to produce initial oscillationthereof in a given plane; and mechanico-electric translating apparatus having surface in spaced relation .to said string and inclined to said plane, said apparatus being inductively influenced by oscillatory variation of the spacing between said string and said surface.

6. In a musical instrument, the combination of a, tuned string; exciting means therefor adapted to produce initial oscillation thereof in a given plane; a conductive member having a surface in spaced relation to said string and inclined to said plane, said surface forming an electrical capacity with said string; and means for maintaining a relatively constant charge in said capacity.

.7. In a musical instrument, the combination of a tuned string; exciting means therefor adapted to produce initial oscillation thereof in a given plane; a condenser plate arranged adjacent said string and inclined to said plane; and an electric circuit connected to said string and said condenser plate.

8. In a musical instrument, the combination of atuned string; exciting means therefor adapted to produce initial oscillation thereof in a given plane; a magnet; a winding carried by said magnet; and a pole piece forming part of said magnet and inclined to said plane.

9. A piano comprising bass strings, mid strings and treble strings; hammers adapted to strike said strings and to produce initial oscillation oi each in a given plane; and mechanico-electric translating apparatus having portions in spaced relation to, and arranged to be inductively influenced by, said strings, said portions associated with said bass strings being arranged substan- 5 tially normal to said planes of initial oscillation of said has strings, said portions associated with said mid strings being inclined to said initial oscillation planes of said mid strings, and said portions associated with said treble strings being arranged substantially parallel to said initial oscillation planes of said treble strings.

10. A piano comprising bass strings, mid strings and treble strings; hammers adapted to strike said strings and to produce initial oscillation of each in a given plane; magnets respectively associated with said strings; windings carried by said magnets; and pole pieces forming part of said magnets respectively and respectively adjacent said stringsfsaid pole pieces associated with said bass strings being arranged substantially normal to said planes of initial oscillation of said has strings, said pole pieces asso ciated with said mid strings being inclined to said initial oscillation planes of said mid strings, and said pole pieces associated with said treble strings being arranged substantially parallel to said initial oscillation planes of said treble strings.

11. In a musical instrument, the combination of a tuned string; and a mechanico-electric translating system having two portions each arranged to be inductively influenced by said string, said portions being arranged normally to each other and in spaced relation to said string.

12. Inv a musical instrument, the combination of a tuned string; a mechanics-electric translating system having two portions each arranged to be inductively influenced by said string, said portions being arranged normally to each other and in spaced relation to said string; and selectivelyoperable means for controlling the translations effected by said two portions respectively.

13. In a musical instrument, the combination of a tuned string; two magnets; windings carried by said magnets; and two pole pieces forming part of said magnets respectively, said pole pieces being arranged normally to each other and adjacent to said string.

14. In a musical instrument, a tuned vibrator; exciting means for producing vibration thereof; a pair of translating means for translating from said vibration respectively a series .of oscillations having amplitude-time characteristics substantially corresponding to those of said vibration and a series of oscillations having amplitude-time 56 characteristicssubstantially modified therefrom; and selective-means associated with said translating means for controlling the relative amplitudes of the oscillations of said two series.

00 OSKAR VIERIJNG.

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