US2111334A

US2111334A - Stringed musical instrument

Info

Publication number: US2111334A
Application number: US29325A
Authority: US
Inventors: Clarence W Russell
Original assignee: DUANE PRATHER
Current assignee: DUANE PRATHER
Priority date: 1935-07-01
Filing date: 1935-07-01
Publication date: 1938-03-15
Anticipated expiration: 1955-03-15

Description

March 15, 1938. c. w. RUSSELL 2,111,334

STRINGED MUSICAL INSTRUMENT Filed July 1, 1935 2 Sheets-Sheet l n1 III-IIIII-III l nllllllllll I lnvcnlor C. W. Russell pmm A Home};

March 15, 1938. c. w. RUSSELL STRINGED MUSICAL INSTRUMENT Filed July 1, 1935 2 Sheets-Sheet 2 C. W. Russell Patented Mar. 15, 1938 STRINGED MUSICAL INSTRUMENT Clarence W. Russell, Longton, Kans., assignor of one-hall. to Duane Prather, Longton, Kans.

Application July 1, 1935, Serial No. 29,325

3 Claims.

My invention relates generally to means for producing and transmitting to a remote point vibrations corresponding to musical tones, and particularly to a stringed musical instrument which is operatively connected to electrical amplifying and recording means whereby sounds engendered by playing upon the strings thereof may be transmitted and amplified with perfect naturalness.

Another important object of my invention is to provide an instrument of the character indicated above which is not subject to the production of varying and distorted tones because of vibra-" tions of the strings in different and divers directions, and in which all restrictions to the natural and full vibration of the strings are eliminated and the full value of the vibrations electrically transmitted.

Another important object of my invention is to provide means of the character indicated above which does not utilize any sound box and is devoid of the conventional sound opening. I

Another important object of my invention is to provide an instrument of the character indicated above which includes electrical means in magnetic relation to the magnetically permeable strings of the instrument, which is effective for transmitting the vibrations unimpaired for reproduction and amplification, notwithstanding vibration of the strings in different directions and at different frequencies.

Another important object of my invention is to provide in an arrangement of the character indicated above electrical means whereby the frequency vibrations of the strings are perfectly electrically transformed into a correspondingly alternating current of the same frequency or frequencies, whereby reproduction of the sounds in an electrical manner is perfectly achieved with the same volume, notwithstanding the fact that the string or strings may be vibrating in different and divers directions.

Other important objects of my invention will be apparent from a reading of the following de- Figure 4 is an end elevational view taken from the bottom of Figure 3 and looking upwardly.

Figure 5 is a transverse vertical sectional view taken through Figure 3 approximately on the line 5-5 and looking upwardly in the direction of the arrows.

Figure 6 is an elevational view looking from right to left in Figure 3. I

Referring in detail to the drawings, the numeral 5 generally designates the hollow instrument body 6 which may be in the form of a guitar having the neck I and the nut Ill thereon.

' The magnetically permeable strings 9 preferably of steel are stretched between the nut I0 and the tail piece l2 over the bridge H which rests on the top 6' of the instrument. It is to be noted that the top of the instrument is devoid ofa sound hole as is present in conventional instruments of this general type.

At one side of the strings the top 6' is provided with a potentiometer switch handle [3 for controlling a resistance in the wires I! which connect with the inductive winding of the pickup unit I 6 andwith the jack l4 which is mounted in a side wall of one end of the body of the instrument and has extending therefrom the wires I6 which lead to a suitable sound reproducing and recording and amplifying device (not shown) The pick-up unit 16 is mounted in an accommodating opening in the top 6' between the bridge H and that part of the strings which have the greatest amplitude of vibration and which lie between the finger board and the bridge.

The pick-up unit 16 comprises the rectangular frame, which includes the rectangular elongated magnetically permeable bar I8 from whose left end rises the vertical magnetically permeable rectangular cross-section bar l9 and from whose right end rises a vertical non-magnetic rectangular cross section bar 20. Screws 22 mount the vertical members l9 and 20 on the base 18. The top piece 2| is also a rectangular elongated magnetically permeable bar and is secured to the tops of the vertical members l9 and 20 by screws 22, thereby forming a permanent magnet of U- shaped form. The bars l8, l9 and 2| form a U- shaped permanent magnet supported at its open end by the vertical non-magnetic rectangular cross section bar 20. It will be evident from Figures 4 and 5 that the vertical members i9 and 20 are angulated with respect to the perpendicular and with respect to the base I8 and the top member 2|, so that the member 2| is displaced toward the keyboard with respect to the perpendicular toward the right in Figures 1, 2, 8, 4 and 5.

The member ii of magnetically permeable metal has depending therefrom a number of lugs a corresponding in number and position to the strings I, and each lug is provided with a horizontal opening 21 receiving the corresponding string and of a diameter sufficient to permit full and unobstructed vibration of the string I.

To the left of the lugs it are magnetically permeable risers 80 which are magnetically connected to the base It and which correspond in number and are vertically aligned with the lugs 2!. Each riser ll has on its upper end a vertically projecting lug it which is provided with a horizontal opening it therein which corresponds in size and in axial alignment with the openings 21inthehigs2|,andthestringslpassalso throushtheopeningsllofthelugsll.

Wound horiaontally around the risers II are turns of relatively nne wire which form the coil 82 which is in inductive relation to the permanent magnet by this arrangement and has its opposite ends connected to the reproducing and amplifying unit by the wires i'i already described.

Each vertical side member II, It has a respective ear II, 24 which has a screw receiving opening 2! to receive a bolt or screw for attaching the reproduction unit to the top I of the instrument.

overlying and extending from all sides of the lugallistheheadli whichconilnesthecoilfl in place.

Bythe arrangementdescribedthetopmember Ii becomes the south pole of a permanent magnet while' the base il becomes the north pole thereof. The coil 82 being in inductive relation to this permanent magnet. there is induced in the coil 32 by the vibration of the strings O variations in the magnetic field which correspond exactly in frequency to the vibrations of the strings and the amplitude thereof. so as to produce alternating current in the wires I! which leadto the reproducing and amplifying device which may be of any suitable conventional type. v

The strings f are conventionally arrang with the base or lowest frequency vibration string uppermost as shown in Figure 2 and the highest frequency string lowermost. The magnet exerts its greatest force at the open end thereof whereat the non-magnetizable member II is located and consequently the apertured elements immediately surrounding the lowest vibration frequency string exert the strongest inductive efl'ect. The next pair of apertured elements surrounding the next higher frequency string exert a smaller magnetic action and, therefore, this next higher frequency string exerts by its vibration a smaller inductive effect. The apertured elements surrounding the highest frequency string being farthest from the strong end of the magnet exert the smallest inductive effect upon the coil I! of any of the strings. By means of this arrangement, the recording device is caused to reproduce the sounds of the different strings in substantially the same volume, notwithstanding the fact that the dinerent strings mechanically vibrate at different frequencies. In this way is overcome the serious defect of other arrangements of this general character in failing to reproduce with suitable equality of volume the sounds and tones which have their origin in mechanical elements producing them by vibrating at different frequencies.

It will also be evident that by the described arrangements equal volume is produced from each individual string regardless of the diiferent and divers directions in which the strings are made to vibrate.

Although I have shown and described herein a preferred embodiment of my invention, it is to be definitely understood that I do not desire to limit the application of the invention thereto. and any change or changes may be made in the materials, and in the structure and arrangement of the parts, within the spirit of the invention and the scope of the subioined claims.

What is claimed is:-

1. A musical instrument of the character described comprising a body portion including magnetically permeable strings of progressively different vibration frequencies stretched thereacross. an electro-magnetic pick-up unit mounted on said body and including a permanent magnet having portions of opposite magnetic polarity spaced longitudinally along each string and in effective magnetic relation thereto, said magnet having coil means thereon whereby alternating currentsareproducedinsaidcoilmeans correspondinginfrequencytothe frequencyof the vibrations of the respective strings when the strings are played upon. the magnetically strongest of said portions of said magnet being arranged in effective magnetic relation to the lowest frequency string and progressively less magnetically strong portions of said magnet being arranged in effective magnetic relation progressively relative to the lower frequency strings, said permanent magnet comprising an upper arm lyingaboveandacrosssaidstringaalowerarmof opposite polarity lying below said strings, each of said arms having a lug connected thereto and extending therefrom and formed with an opening receiving and having its sides spaced from the corresponding individualstring. a magnetically permeable member connecting said arms at one end only,saidcoilmeansbeingwoundon magnetically permeable members projecting from one of said arms.

2.A musical instrument comprising a body having magnetically permeable strings stretched thereacross, said strings having different mechanical vibration frequencies. an electrical pickup unit mounted on said body, said pick-up unit comprising a permanent magnet having coil means wound on a part thereof. said permanent magnet havinganupperarmiyingacross and spacedabovesaidstringaalowerarmlying across and spaced below said strings. said arms being of opposite magnetic polarity, and a yoke Joining the upper and lower arms at one end thereof, said arms each having a magnetized portion surrounding and concentrically spaced from each string in effective magnetic relation thereto, the said magnetized portions being distributed along said arms so that the magnetized portions surrounding the strings of weaker vibration will exert greater magnetic force thereon and the magnetlsed portions surrounding the more strongly vibrating strings will exert less magnetic force, whereby the electro-magnet effect of the vibrations of the different strings is equalized. and alternating currents of equal value are set up in said coil means for actuation of a reproduction unit regardless of the strings P yed upon and regardless of the different directions in which the individual strings are made to vibrate.

3. A musical instrument comprising a body having magnetically permeable strings stretched thereacross, said strings having diflermt mechanical vibration frequencim, an electrical pickupunitmountedonsaidbodamididebupunit comprising a permanent magnet having coil means wound on a part thereof, said permanent magnet having an upper arm lying across and spaced above said strings, a lower arm lying across and spaced below said strings, said arms being of opposite magnetic polarity, and a yoke joining the upper and lower arms at one end thereof, said arms each having a magnetized portion surrounding and concentrically spaced from each string in effective magnetic relation thereto, the said magnetized portions being distributed along said arms so that the magnetized portions surrounding the strings of weaker vibration will exert greater magnetic force thereon and the magnetized portions surrounding the more strongly vibrating strings will exert less magnetic force, whereby the electro-magnet effect of the vibrations of the different strings is equalized, and alternating currents of equal value are set up in said coil means for actuation of a reproduction unit regardless of the strings played upon and regardless of the different directions in which the individual strings are made to vibrate, said magnetized portions each comprising a 'ug projecting from the corresponding arm of the permanent magnet and formed with a bore having its axis parallel to that of the corresponding string, the lugs for each string being axially spaced along the strings.

CLARENCE W. RUSSELL.