Electronically Operated Stringed Instruments

Abstract

Stringed instruments such as the guitar, mandolin, contrabass and piano are operated electronically instead of by hand, plectrum or percussion. Circuitry is provided for operation and control. The instruments are otherwise conventionally constructed.

Description

In instruments of conventional construction such as the guitar, mandolin, contrabass and piano, sound emission is effected by plucking strings by a plectrum or percussion by means of hammers, and although such instruments have in the past been connected into electrical circuits, such has been for amplification purposes or for giving modified tonal qualities to the instrument.

According to the present invention, such instruments, instead of being operated in the conventional manner or merely connected into an amplifying electrical circuit, are provided with electronic buttons or oscillators connected into electrical circuits in such manner that sounds are caused to be emitted by the instrument through electronic operation and, in the case of the guitar, for instance, the changes in sound or string vibrations, and therefore, pitch or tone, are carried out by means of the electronically operated elements, buttons or pegs which are located in the same relative positions as if the instrument were to be played in the normal or conventional manner. In a guitar, which is the particular example of the present invention, the central portion of the sound box is provided with buttons which can be actuated to emit the basic note or tone, and pegs are provided along the neck of the instrument to vary the sound emission relative to the basic sound in contrast to the usual way of playing a guitar wherein the tonal sounds are obtained by finger pressure on the strings and the moving of the fingers along the strings to reduce or increase the effective vibratory length of the strings, musically speaking, so as to raise or lower the note or tone respectively as a result of changes in frequency of vibration.

In a piano, where the strings are struck by hammers at full string and therefore with fixed tone, there need be only keys for basic tone emission according to the present invention.

In the accompanying drawing:

FIG. 1 is a top plan view partially broken away of a guitar with pegs and buttons for electronic operation according to the invention;

FIG. 2 is a side elevational view taken on line A--A of FIG. 1 of an actuating button and its related dual contact switch;

FIG. 3 is a cross-sectional view taken on line B--B of FIG. 1 showing a plurality of actuating buttons;

FIG. 4 is a side view taken on line C--C of FIG. 1 of certain of the tone changing pegs and their related electric circuit portions;

FIG. 5 is a cross-sectional view taken on line D--D of FIG. 1 illustrating a plurality of tone changing pegs;

FIG. 6 is a partial top plan view and partial sectional view taken on line E--E of FIG. 5 of a part of a guitar neck;

FIG. 7 is an electrical diagram illustrating the basic principle on which a guitar is operated according to the invention and,

FIG. 8 is a view similar to FIG. 7 of an electrical diagram for use in operating a piano according to the invention.

Referring to the drawing, numeral 1 designates the sound box of a guitar having a neck 2. These portions of the guitar are of conventional construction. The central part of the sound box is, however, provided with a series of exciting or actuating buttons 3 and a row of pegs 4 for changing the tone or note to be emitted as a result of changes effecting length and vibrational frequency. The number of buttons 3 and pegs 4 is equal to the number of strings and frets or pressure points which they replace and the number of pegs 4 in each row is sufficient to enable all the desired or necessary tonal vibrations for each string to be obtained analogously through the frets or pressure points of a conventional instrument.

As further shown in FIGS. 2 and 3, each button 3 is pivoted at one end on a pintle 5 transversely mounted as shown and therebelow is a contact member 6 supported by or on a bracket or shelf 7 so that a pivotal movement of a button 3 about pintle 5 completes an electrical circuit which is immediately disconnected when button 3 is permitted to rise as occurs when the spring-like element 6' urges the button upwardly, said spring-like element being itself resiliently mounted at one end 6" as shown in FIG. 2. Thus, each button 3 causes sound emission when depressed and is automatically returned to original position when released, each contact having a charging and discharging position for condenser 8 as more fully described hereinafter.

As will be seen from FIGS. 4-6, each tone changing peg 4 is provided with a spring plate 9 on its underside affixed to an insulating circuit 10 by means of rivets or the like 11, which are electrically connected to one another row by row. Some pairs of contacts 12 and 12' connected to resistances 13 are arranged in row by row series and are located under the ends of each spring plate 9 of the same insulating plate. In FIG. 4, the broken lines are intended to designate electrical connections.

Referring to FIGS. 1 and 7, it will be seen that there is a button 14 acting on different contacts 14', each button serving to prevent or damp sound emissions by causing immediate discharge of condenser 8. At the end of the neck of the guitar, there is also a plurality of variable resistances 15 in the form of buttons which are used for tuning purposes.

Referring next to the operation of the instrument and FIG. 7 which illustrates the basic electrical diagram, it will be seen that a button 3 for a basic tone or note has an underlying contact element 6 capable of assuming two positions, in one of which the circuit is open and in the other of which, the circuit is closed. The position of contact element 6 in FIG. 7 is the closed position. In the circuit, there is a condenser 8 of fixed capacity to which current is fed from battery 16 when button 3 is lowered and contact element 6 closes the circuit. But when the button 3 is in its upper position, as shown in FIG. 7, then the charging of condenser 8 stops and the current is fed to the preamplifier 17 to the point of complete discharge. The preamplifier acts as an intermediary between the oscillator 18 and the sound filter box 19 connected to loudspeaker 20. Oscillator 18 is in a circuit which provides as many resistances 13 as are necessary to the basic notes or tones and corresponds to the points on which pressure is placed manually on the strings of a conventional guitar. The circuit is also provided with a variable resistance 15 by means of which the current flow can be suitably altered thereby varying the basic note or tone emitted.

FIG. 7 also shows the relationship of the pegs 4 heretofore described and the spring plates 9 disposed below them and all electrically connected so that when a peg 4 is lowered, contacts 12--12' are closed to connect the resistances 13 which are arranged in series. There is also a contact 14' which is shown in open position but which when closed, damps or eliminates all sound and results in the discharge of condenser 8. Contact 14' is actuated by button 14 on a box portion of the guitar.

It is to be understood further that in place of each string of a conventional guitar, there is provided a combination of button 3, row of pegs 4 and a preamplifier 17 together with an oscillator 18 and the contact of 14', already referred to, which has only a single actuating button. It has only been found necessary to have a single loudspeaker or amplifying system and a single timbre filter box.

When it is desired to operate the guitar, a button 3 is depressed--or more than one is depressed as desire--until contact 6 is completed and lowered to meet condenser 8, whereupon the condenser charges. When button 3 is released, i.e., when pressure thereon is removed, the contact 6 rises and the condenser then acts to feed preamplifier 17 enabling the passage of the oscillations being emitted from a resonant circuit, it being understood that the resistances 13 connected thereto transmit the oscillations to loudspeaker 20 with decreasing intensity proportional to the intensity supplied by the condenser similarly to the sound of the vibrating string which gradually is damped.

In addition to depressing button 3, a peg 4 in the same row can also be actuated thereby cutting off certain of the resistances 13 from the resonance circuit and in this way, the oscillation frequency varies as well as the volume of sound which is approximately equal to the sound and tone quality of a conventional guitar in which a string has been plucked at the point where peg 4 has made contact.

It is further to be understood that the sound box of the guitar which can be used as the container for the electrical equipment may be provided with any suitable appliances which enable the sound timbre to be varied through the filter box 19 and to be modulated with "vibrato" and "riverbero" which make a guitar versatile in tonal sounds and tonal combinations. Similar arrangements apply to other stringed instruments such as a mandolin and a contrabass.

In FIG. 8 a basic electrical diagram is illustrated for the operation of an electronic piano. Those numerals in FIG. 8 which are the same as in FIG. 7, designate like pieces of equipment but it will be observed that the connections of the contact 6, which is a dual contact, is inverted with respect to the operation of the element 6 which is now a piano key or equivalent. This inversion is necessary because, as in a conventional piano, sound must be emitted when a key is depressed and in the electrical diagram of FIG. 8, the lifting of a key 6 causes the condenser 8 to be charged but when it is lowered, the condenser is connected to and feeds the preamplifier until complete electrical discharge of the latter or until the key is permitted to rise.

In the case of the piano, it is unnecessary to provide the resistance 13 as for a guitar or mandolin, as the basic sound or tone is not varied and there need only be a variable resistance 15 for tuning of the piano. The contact 14 of FIG. 7 can also be eliminated because the lifting of a peg 6 in FIG. 8 automatically avoids the emission of any sound. To play music on a piano according to the present invention, it is necessary to extend the sound of the notes even when the key is lifted as well as to damp the sound and in order to accomplish this, there is an additional condenser 21 parallel to condenser 8 which operates upon movement of the pedal 22 located on the dual contact 23, this being the upper position of rest since the lower position in which condenser 21 is fed through condenser 8, the key being lowered or depressed at such time, the preamplifier is fed even when key 3 is released. Means are also provided to damp the sound in the form of resistance 24 which is in parallel to condenser 8 and which stays in operation by a closing of the contact 25 by pedal 26, thereby resulting in a quicker discharge of condenser 8.

Claims

What is claimed is:

1. In an electronically operated musical instrument simulating a plucked string instrument and having means for generating an electrical output characteristic of a musical tone for transmission to a loudspeaker through a timbre filter box, the improvement which comprises:

a. a frame approximating that of a standard stringed instrument;

b. a plurality of basic tone buttons mounted on said frame, each button being mounted for movement between a normal raised position and lowered position;

c. spring means urging each of said buttons to the raised position; and

d. a plurality of circuits connected to an energy source, one circuit for each of said buttons, each of said circuits comprising

1. electrical switching means mounted below and movable by said button associated with it,

2. a preamplifier electrically connected to and capable of feeding an amplified output to said loudspeaker through said timbre box,

3. a resonance oscillator electrically connected to and feeding said preamplifier with an output signal characteristic of a tone of a given frequency, and

4. a condenser electrically connected to said energy source and to said preamplifier through said switching means so as to be charged when said button is in its lowered position and to discharge to and activate said preamplifier when said button is allowed to return to its raised position

whereby upon decay of the current discharged from said condenser a damping effect on the sound, emitted by said loudspeaker upon activation of said preamplifier, is produced.

2. The improvement in electronically operated musical instruments according to claim 1 wherein said oscillator comprises a resonant circuit having a variable resistor for tuning, a plurality of fixed resistors connected in series and normally open switching means for progressively cutting out said resistors to vary the frequency emitted by the oscillator.

3. The improvement according to claim 2 including a plurality of secondary buttons arranged in rows, one row for each of said basic tone button, each of secondary buttons being operable to close the normally open switching means of the resonant circuit, said secondary buttons being placed at points corresponding to those at which pressure is manually applied to the strings of stringed instrument, whereby upon depression of one of said buttons a predetermined number of fixed resistors are cut out of said resonant circuit and the output signal of the resonant oscillator is raised in frequency from that characteristic of the "open string" tone to a higher "stopped string" tone.