Percussive musical instrument with transducer for actuating an electronic tone generator

[57] ABSTRACT

A microphone is positioned adjacent a playing member capable of being struck with drum sticks, foot-operated beaters, or the like. The electric output of the microphone, in response to such striking, is rectified and added to the electric potential supplied to an electronic audio tone generator, to activate the latter and produce a desired tone. The generated tone is amplified and fed to an audio speaker, headphone, recording instrument, or other audio output device.

Claims, 3 Drawing Figures

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PATENTED &gt;24 «73

3.748,367

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3ώ

Stephen J. Lomme Thomas J. Holce INVENTORS

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3,748,367

PERCUSSIVE MUSICAL INSTRUMENT WITH TRANSDUCER FOR ACTUATING AN ELECTRONIC TONE GENERATOR

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of earlier filed application, Ser. No. 72,688, filed Sept. 16, 1970 now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to percussive musical instruments, and more particularly to a novel electronic musical instrument of the percussion type.

Conventional percussion instruments, such as drums, have certain inherent limitations. For example, they are limited to narrow ranges of tone, as dictated by specific structural materials and range of adjustment. They present serious problems in recording, since required microphone pickup results in feed-back distortions. These limitations are overcome in electronic percussion instruments.

Electronic percussion musical instruments provided heretofore utilize switches, closed momentarily by finger-operated keys, to activate electronic tone generators designed to produce desired tones. The principal disadvantages of such arrangements are (1) they are incapable of producing variable tone volume proportional to the pressure applied by the fingers; (2) they are incapable of being operated at speeds suitable for manipulation by drum sticks; and (3) their use therefore is limited to only a few types of percussive instruments.

SUMMARY OF THE INVENTION

In its basic concept the percussive musical instrument of this invention involves the use of a transducer to produce an alternating current electric signal in response to the percussive effect of striking a playing member located adjacent the transducer, the electric signal functioning to activate an audio tone generator to produce a desired tone.

It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, to overcome the aforementioned disadvantages of conventional percussion instruments and prior electronic percussion instruments.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawing of the preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view of a drum showing, in broken lines, the association of an audio frequency transducer.

FIG. 2 is a sectional view taken on the line 2—2 in FIG. 1.

FIG. 3 is a schematic diagram of an electric circuit forming a part of the electronic percussive musical instrument of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For purposes merely of illustration, FIGS. 1 and 2 show a drum in somewhat conventional shape, but of considerably different structural arrangement. Thus, the drum includes a substantially cylindrical side wall 10 closed at its upper end by an end plate 12. This end plate is connected to the side wall by an intervening annular bead 14 which projects upward from the plate.

The plate 12 constitutes a playing member, the upper surface of which is adapted to be struck by a playing 5 implement such as drum sticks, foot-operated beaters, the fingers of a player, and the like. The plate may be made of any desired material such as wood, metal, synthetic plastic, etc. In the embodiment illustrated it is formed integral with the side wall and bead by the spin 10 casting of aluminum or other desired metal. Thus, the playing plate is substantially rigid, as distinguished from conventional drum head skins which must be made of flexible material capable of being stretched adjustably to provide a desired tone. Although the playing plate 15 may be provided in the form of a flexible membrane, it is not required since the tone is generated electronically, as described hereinafter.

The playing plate 12 may be utilized per se as the member to be struck by a playing implement. However, 20 it is preferred that the playing surface of the plate be covered with a resilient material 16 such as natural or synthetic rubber, synthetic plastic, cloth, or other suitable material which enhances the action of drum sticks and provides a softer sound which does not interfere 25 with the electronically produced tones described hereinafter.

The open bottom end of the cylindrical side wall 10 preferably is closed by a bottom plate 18 which is secured to the side wall by such means as screws 20.

³⁰ In accordance with the present invention, a transducer 22 is positioned in contact with or adjacent the playing member 12 appropriately to receive the percussive pressures resulting from the striking Of the playing member and to convert them to electric output signals.

³⁵ The transducer may be a conventional microphone, or audio frequency speaker arranged to operate as a microphone, and it may be secured directly to the playing member 12 on the side opposite the playing surface, as illustrated in FIG. 2, or it may be mounted in spaced re⁴⁰ lation to the playing member, as desired. For example, the transducer may be mounted on the bottom plate 18 in spaced relation to the playing member 12.

It is preferred that the transducer 22 be a dynamic speaker of rectangular configuration associated with a 45 round drum, as illustrated in FIG. 1. In this regard it has been found that such an arrangement provides a greater variation in tone volume by striking the playing member at various locations on its circular surface, relative to the rectangular speaker. However, the drum may be of any other desired shape, such as square, rectangular, triangular, oval, etc.

It will be understood, of course, that the playing member may be provided in any form desired. For example, it may be formed in the shape of a base drum, ³ arranged to be operated by a foot pedal-operated beater, a tom tom, bongo, bell, cymbal, triangle, or other desired form of instrument. In the snare drum arrangement illustrated, drum sticks may strike upon the ₆₀ resilient covering 16 of the playing member to produce ^u appropriate tonal qualities, or upon the metallic bead 14 to produce tones of more staccato characteristics.

It will be further understood that the microphone 22 described hereinbefore may be replaced by various ₆₅ other forms of transducers which function, in response to intermittent percussive pressure applied thereto, to produce alternating current electric signals. For example, a piezoelectric crystal may be employed for this

3,748,367 purpose to produce electric signals at any desired alternating current frequency in response to the percussive effect of striking a playing member placed in direct contact with or located adjacent to the crystal.

Referring now to FIG. 3 of the drawing, the electrical output of the transducer is connected to the primary winding of a step-up transformer 24, the secondary winding of which is connected across the input of a full wave rectifier 26. One output terminal of the rectifier is connected through a potentiometer 28, battery 30 and control switch 32 to ground. The other output terminal of the rectifier is connected through a resistance 34 to a tone generator 36 to provide electrical potential for the latter. In the embodiment illustrated the tone generator is a conventional twin T oscillator, the frequency of which is determined primarily by the values of the resistors 38 and capacitors 40. A potentiometer 42 functions to vary the frequency slightly over a limited range.

A sensitivity potentiometer 44 functions to adjust the potential from the battery 30 to a level just below activation of the oscillator. Thus, when the playing surface is struck by a playing implement the resulting electric output signal is rectified and added to the battery potential to bring the level up to activation of the oscillator. This level also may be adjusted by the ringing potentiometer 28 which functions to vary the duration of oscillation and hence the tonal quality output from the tone generator. This potentiometer also may be adjusted to effect continuous operation of the oscillator, if a steady output tone is desired.

The electric output signal from the oscillator 36 is fed through a resistance 48 to the input of a preamplifier assembly 50 which may constitute one or more stages of preamplification. The output from this assembly is fed to the input of a power amplifier 52, the output of which is fed to an output audio frequency speaker 54.

As indicated in broken lines in FIG. 3, any desired number of tone generators 36 may be included in the system, by parallel connection with the tone generator illustrated in full lines. Appropriate switches (not shown) are associated with the plurality of tone generators for connecting them selectively in the circuit. In this manner a wide variety of tones may be provided by operating on a single playing member 12.

A plurality of the foregoing systems may be combined into a composite assembly. Thus, for example, a complete drum assembly of snare, base, tom tom, cymbal and any other desired components may be arranged in conventional playing manner, each provided with a plurality of tone generators.

If desired, a headphone 56 may be connected, either at the output of the preamplifier assembly 50 or at the output of the power amplifier 52, for use by the player during practice sessions.

Further, the amplified output from the preamplifier assembly or power amplifier may be connected directly to the input of recording apparatus. As previously explained, such an arrangement avoids the problem of feedback distortion which occurs when microphone pickups are required.

The arrangement illustrated and described hereinbefore offers the additional advantages of providing full dynamic range over any desired frequency range. The arrangement is of simplified construction for economical manufacture and requires minimum maintenance.

It will be apparent to those skilled in the art that various changes in the size, shape, number, type and arrangement of parts hereinbefore may be made. For example, the battery supply 30 for the oscillator 36 may be connected directly to the latter, i.e., by connecting the upper end of the ringing potentiometer 28 to the collector of the transistor. The arrangement illustrated is preferred, however, since it minimizes the magnitude requirement of the signal from the step-up transformer and accommodates the incorporation of a greater number of tone generators in the system. The twin T oscillator illustrated may be replaced by any other conventional form of tone generator, as desired. These and other changes may be made without departing from the spirit of this invention.