US3539699A

US3539699A - Two-in-one stringed electronic instrument with string pickup and tone generator

Info

Publication number: US3539699A
Application number: US611930A
Authority: US
Inventors: Richard A Johnson
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-01-26
Filing date: 1967-01-26
Publication date: 1970-11-10
Anticipated expiration: 1987-11-10

Description

Nov. 10, 1970 R. A. JOHNSON 3,539,699 Two-IN-ONE-STRINGED ELECTRONIC INSTRUMENT WITH STRING' PICKUP AND TONE GENERATOR Filed Jan. 26, 1967 @i gg afa. H32

f IK/Em 1 EN El JNVENTOR.

4,/ 4,7 ardJ//ffe United States Patent Ofce 3,539,699 Patented Nov. 10, 1970 3,539,699 TWO-IN-ONE STRIN GED ELECTRONIC INSTRU- MENT WITH STRING PICKUP AND TONE GENERATOR Richard A. Johnson, 1708 N. Quesada St., Arlington, Va. 22205 Filed Jan. 26, 1967, Ser. No. 611,930 Int. Cl. G10d 5 00; G10h 1/00, 5/04 U.S. Cl. 84--1.16 5 Claims ABSTRACT F THE DISCLOSURE A stringed instrument such as a guitar which utilizes an electronic amplifier coupled to not only reproduce the tones introduced in the strings via a pickup but also selected additional supplemental tones electronically generated. Thus, a fretboard provides electrical switches selectively positioned for individual selection or concurrent selection while fingering a string for thereby selecting supplemental chords or organ-like tones while the instrument is otherwise conventionally played. The neck of the instrument is hollow, containing the switches and associated electronic parts, which are in the form of a printed circuit board having communication with the switches and establishing precisely determined resistances from a single resistive strip by means of a fine tuning slide for each switch. To prevent warping of the hollow neck under tension of taut strings, they are stretched over the end of the neck and back on an opposite side to have both ends aiiixed to the instrument body, thereby balancing the forces tending to bow the neck portion.

This invention relates to an electronic string instrument and, more particularly, it relates to an electrically supplemented string instrument which selectively produces auxiliary tones from an electronic tone generator.

While electronic guitars have been known having both electronic amplified string vibrations and supplemental tones (as evidenced by U.S. patent 3,116,357) these instruments have not provided suiiicient diversity of controls to serve as two different instruments either of which can be played individually or both of which can be played in unison without significally different manual movements.

Thus, it is an objective of this invention to provide improved electrically supplemented string instruments in which essentially one instrument may be played with tones entirely electronically generated such as in an electronic organ, and wherein this instrument may be played individually with or without any relationship to the playing of the string instrument itself.

This invention therefore provides for a set of electrical switches in the fretboard of a guitar which select corresponding tones from an electronic tone generator. Each switch is located adjacent a string in such location that the string may be fingered with or without closing the switch, and the switch may be closed without playing the string instrument. Electronic selection devices are located with the switches within a hollow neck which has strings extending over the end and along both sides to balance forces tending to bow or twist the neck.

The foregoing and further objects, features, and advantages of the invention are realized in an embodiment set forth in the following specification and its accompanying drawing, wherein:

FIGS. 1 and 2 are respectively elevation and plan views, partly broken away, of a guitar constructed in accordance with the invention;

FIG. 3 is an electrical system diagram illustrating the principles of the invention;

FIG. 4 is an elevation view in section of a portion of the guitar neck-fretboard arrangement; and

FIG. 5 is a plan view of printed circuit boards located within the guitar neck.

Now with reference to FIGS. 1 and 2, the guitar ernbodiment illustrated has a body portion 6 and a hollow neck portion 7 with a fretboard 8 exhibiting frets 9 on the upper side and having strings 8a stretched around the terminal end 10 and indented rollers 10a to extend on the underside 11 and terminate in tension pegs 12 on the bottom of the body portion, which provides balanced stresses thereby eliminating any need for a steel brace rod and providing rigidity in the greater capacity hollow neck without tendency to bow or bend.

Electronic parts are located within the hollow neck portion 7 as show-n on printed circuit board 15 for example and include a set of electrical switches 16, 16', etc. each switch of which is adjacent a string at a fret position so that it may be selectively operated by a fingertip either simultaneously with a fingering of the string or individually without affecting the adjacent string. Also individually pickup transducers 20' for each string are located within the hollow body 6. Electrical connections may be made from the guitar body to a single amplifier system from cable 24 necessitating only two leads 25, 26 plus ground lead 27.

As shown in FIG. 3, a typical electronic system provides a single audio amplifier 30 into which signals from all the strings may be introduced via lead 25 from mixing resistors 31 and corresponding transducers 20. A tone generator such as resistance controlled oscillator 33y is also connected to the amplifier via mixing resistor 32.

In oscillator 33 the frequency adjustment comprises a variable resistor 34 which is selectively adjusted by choice of an appropriate selection switch 16, etc. to choose a tone simulating an organ or a chord for example. It is to berecognized that the mixing and frequency selection techniques need not be exactly those shown to comply with the spirit and scope of this invention, and that various oscillators or tone devices may be used for selection by the electrical switches 16. However, a versatile and simple combination is provided by the single oscillator 33 provided with a single variable resistor 34, particularly when constructed in the manner hereinafter taught in connection with the views of FIGS. 4 and 5.

Thus, under fretboard `8 is the hollow cavity of neck 7 from which switch buttons 16 protrude adjacent strings r8a in the vicinity of frets 9. This button is spring biased by spring 40` electrically soldered to grounding wire 27 and is fashioned to contact a protuberance 41 at a fixed position on a set of electrical conductor segments 42 disposed on the upper side of printed circuit insulator board 15. If desired, several rows of such conductors may be disposed in connection with the several instrument strings to communicate with either a single resistor 34 in oscillator circuit 33 or with separate similar individual resistors in a plurality of tone generators.

Disposed on the bottom of the board is a long strip 45 of resistance medium comprising resistor 34. A variable resistance coupling is made from each push button switch 16 to a particular line tuned position on resistor 34 by means of a U-shaped bracket or strap 46 indented at `47 to make conductive Contact on opposite sides of the printed circuit board 15 respectively to the resistive strip 45 and one of the conductive portions 42. Thus, the fine tuning strap `46 can be adjusted to choose a resistance within the limits defined by the length of the respective conductive portion 42.

It is seen therefore that simple and effective equipment is afforded by this invention to provide an improved string instrument which operates either to produce solos on .means single musician. Having therefore provided an improved instrument, I claim as my invention those features describedin 4the appendedclaims as representative'ofithe neck extendingfrom said body with a, fretboard thereon for lingering the strings at a set of fret positions, a set of manually. operable velectrical switches `placed adjacent [.twq diiferentinstrumentsor duets.,by operationvofa Vprisingl in combination, a body containing a plurality of vvibrating strings for producing different musical tones, a

,the strings and frets in saidneck for selective operation independently withirespect to. the iingering of a string yat an adjacent fret, electronic amplifier means, electrical signal generating means for reproducing tones from each of the vibrating strings, an auxiliary tone generator, means 'coupled with the switches to establish different tones in said generator, and meansfor independently and selec- `tively mixing the signals from said generating means and said tone generator for reproduction in said amplifier 2. An instrument as defined in claim 1 wherein said i f 3. An instrumentA as defined. in claim `1 wherein said :neck is a hollow shell into which said switches protrude 4and said tone generator is responsive toa change in resistance to change tones, including an electronic circuit assembly contained within said neck including means selecting a series of different resistances in response to operation of said switches in said generator and means coupling the resistances to said generator to change tones thereby comprising said means to establish different tones,

said electronic circuit assembly comprises a .printed circuit board having on one side a long strip of material of high resistivity to comprise the resistance changing the tone of said generator and having on the other side a set of conductors extending along only a limited portion of said long strip, means coupling said switches respectively to one of said set of conductors, and adjustable conducting means mov able along the conductor and strip to thereby select a particular length of said strip establishing a resistance value corresponding to a finely tuned tone in said generator.

4. A string instrument having a body and a hollow neck portion mounted thereto comprising strings aliixed to and extending from said body along said neck portion to one side and back on the opposite side to a further alixed position on the body to thereby balance stresses in the neck produced by said strings.

5. An instrument as defined in claim 4 whereinindented rollers are provided at the terminal end of the neck to receive the strings and pegs for adjusting the tension of said strings are located on the underside of said body.

References Cited UNITED sTATEs PATENTS 557,277 .2i/1896 Kelly et a1. :s4- 267 586,032 7/1897 Hartman 84-293 3,196,729 7/1965 Bums et a1. 84- 171 3,205,294 9/1965 Maynard 84-l.1l 3,223,771 12/1965 Hopping :s4-1.26 3,116,357 12/1963 Krebs 84 1.16

WARREN E. RAY, Primary Examiner Us. c1. XR. :a4-293, 297