Патент USA US2130174код для вставки
Sept.> 13, 1938. 2,130,174 G. D. BEAUCHAMP STRINGED MUSICAL INSTRUMENT Filed Jan. 14, 1936 J \ FTW@ßww y„W Om 2 Shee‘tS-Sheei- l W _L „„ , a@ / f \ »UQ„ „m ro „a .„d m , wy i* Sept. 13, 1938. G. D. BEAUCHAMP 2,130,174 STRINGED MUSICAL INSTRUMENT Filed Jan. 14, 19256 „.ir-:.5l .É\Y, 2 Sheets-Sheet 2 2,130,174 Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE l 2.130.114 s'ramcsn Musical. ms'raum'r George D. Beauchamp, Los Angeles, Calif., assign or to Electrol String lnstrument Comration, Los Angeles. Calif., a corporation of California Application January 14, 1988, Serial No. 59.032 'iClalma (Cl. 84-1) This invention relates to musical instruments and relates more particularly to electrical musical instruments ot the violin type. A general object oi’ this invention is to provide a practical, com 6 pact and eilective electrical stringed musical in strument. Stringed musical instruments of various char acters have been introduced having electrical pick-up units or electro-magnetic pick-up units 10 for converting the vibrations produced by the strings into modulations in an electrical circuit to be ampliiled and reproduced as music. Ithas been the usual practice to include a pick-up of this character in the instrument in addition to 15 its usual or original sounding board or resonant body; The sounding board or resonant body of a violin or a similar instrument is rather large and cumbersome and renders the instrument diiiicult to handle and play. The embodiment of an elec trical pick-up unit in the instrument in addition to its usual sound board or resonant body of course increases the weight and bulk of the in strument. Another object of this invention is to provide 25 an electrical stringed instrument of the violin type that is extremely light in weight and well balanced, and, therefore very easy to handle and play. Another object oi' this invention is to provide mentioned that is very simple in construction and light in weight, comprising a one piece casting or body forming the neck, the key box portion or peg box portion, and the shoulder engaging portion of the instrument. Another object of this invention is to provide a stringed instrument oi.' the violin type that em bodies a novel, Vsimpli?ed and improved electro magnetic pick-up unit of the general character i'ully described and claimed in my co-pending 10 application Serial No. 728,717, illed June 2, 1934, which has matured into Patent No. 2,089,171", granted August 10, 1937, for converting the vi brations of the several strings into pulsations or modulations in an amplifying sound reproducing circuit. Another object of this invention is to provide a stringed musical instrument of the violin type that embodies an electro-magnetic pick-up unit embodying permanent magnets and a coil be 20 tween the polar parts of the magnets, the mag nets and coil being positioned so that the strings pass between the coil and the proper polar parts of the magnets whereby the vibrations of the strings vary the density of the magnetic flux or 25 disturb the magnetic neld and thus produce an induced current in the coil, the arms of the mag net being dampened to prevent sound producing vibrations of the magnets. Another object of this invention is to provide 30 30 an electrical stringed instrument of the violin n an electrical musical instrument of the charac type that has its center of gravity and its great est mass immediately adjacent its inner end to be supported on the shoulder oi' the player and has a simple, very light stub neck devoid of keys and 35 all other parts, which imposes little or no weight on the fingering hand oi’ the player, making the instrument very easy to play. Another object of this invention is to provide an electrical stringed instrument o! the violin 40 type in which the key box portion or peg box portion is at the inner end of the neck to be ar ranged against the shoulder of the player, as dis tinguished from the usual form of violin in which the peg box is at the outer end of the neck and must be supported by the ñngering hand of the player. _ Another object of this invention is to provide an electrical stringed instrument oi' the violin class that is of novel construction, whereby the shoulder engaging portion or the shoulder pad on such portion comfortably rests on the shoulder of the player and the iinger board of the neck is elevated in the proper position for playing. Another object oi this invention is to provide 55 an electrical stringed instrument ci' the character ter mentioned that embodiesv an electro-magnetic pick-up unit in which the magnets are shaped and the core magnets of the coil are propor tioned and located to have the proper substan 35 tially uniform spaced relationship to the strings which are arranged in a segmental or arcuate series. Another object of this invention is to provide a stringed musical instrument of the character 40 mentioned in which the pick-up unit is very com pact and light in weight and is arranged so that it does not interi'ere with the playing oi' the instrument. The various objects and features of my inven 45 tion will be fully understood from the following detailed description of a typical preferred form and application oi' my invention, throughout which description reference is made to the ac 50 companying drawings, in which: Fig. 1 is a top or plan view o! the instrument provided by the present invention. Fig. 2 is a side elevation of the instrument. Fig. 3 is an en larged transverse detailed sectional view taken as indicated by line 3_4 on Fig. 1. Fig. 4 is an en 2 2,180,174 larged transverse detailed sectional view illus trating one of the string tuning units being a view taken as indicated by line 4_4 on Fig. 2. Fig. 5 is an enlarged transverse detailed sectional view taken as indicated by line 5_5 on Fig. l. Fig. 6 is a fragmentary longitudinal detailed sec« tional view taken as indicated by line 8-8 on Fig. 5. Fig. 7 is a fragmentary elevation view lof the under side of the key box portion of the instru ment showing a part thereof in cross section, be ing a view taken `as indicated by line 1-1 on Fig. 2 and Fig. 8 is a diagrammatic wiring diagram of the circuits involved in the invention. The improved electrical stringed musical in 15 strument of the present invention includes, gen erally, a unitary body A having a neck III, a key box portion or peg box portion II and a portion I2 for engaging the shoulder of the player, ten sioned strings B extending over the fingerboard 20 of the neck I 0 and an electro-magnetic pick-up unit C on the neck I0 for converting vibrations _ oi' the strings B into pulsations or »modulations in .an amplifying circuit. The construction and shape of the body A 25 and the relation between the several parts of the body A are important features of the invention. The body A is preferably formed of metal, or other material that may be cast in the form of a single, integral part or casting. In practice 30 I have found it desirable to form the body A of a synthetic organic substance resulting from the chemical condensation of phenol and formalde v hyde which is relatively light, strong and capable of being attractively finished. In' accordance 35 with the invention the body A is an integral one piece member and provides or forms all of the principal frame parts and supporting parts of the instrument. The neck I0 over which the strings B are strung 40 is an elongate part comprising the forward or outer portion of the instrument. The neck Ill is shaped to be readily and properly engaged and held by the player’s fingering hand. The neck III is preferably tapered both horizontally and ver 45 tically toward its outer end to be of less cross sectional dimension adjacent its outer end than at its inner end where it joins the portion Il. ~ 'I'he lower or under side of the neck I0 is rounded or provided with a convex surface Il. In the 50 preferred construction the neck I0 is tubular or hollow to be light in weight and easy to handle. A longitudinal groove I 5 is provided in the neck I0 and has the same general contour as the external surface of the neck. The fingerboard 55 I 8 of the neck I 0 closes the upper end of the groove I5. 'I'he ñngerboard I6 may be cemented or otherwise fixed in place. The upper side or surface I'I of the finger board i6 is transversely convex throughout the major portion of its length 60 and is shaped and finished so that the strings B may be properly pressed against it. 'I‘he outer end portion I8 of the neck I0 may be slightly enlarged and of ornamental configura tion. A curved or concave surface I9 is provided 65 on the under side of the neck I0 adjacent its ex treme outer end portion I8 to form a stop or abut ment for the hand of the player. The end por tion I8 of the neck Iii is shaped and formed to hold the end portions of the strings B as will be 70 hereinafter described. In accordance with the invention a projection 20 is provided on the under side of the neck I0 at a point spaced between its opposite ends. 'I‘he projection is intended to form a support or abutment engageable by a part of 75 the player’s hand as he engages or ?ngers the strings B. The projection 20 corresponds, gen erally, in function, to the button of a typical violin.. In practice the projection 20 is prei’~ erably integral with the neck I0 and is substan tially round in transverse cross section. l 'I'he invention provides means for locating the playing hand and the string depressing nngers of the player. A member or part l0 projects later ally from the neck I0 at that side of the neck over which the player extends his lingers to depress the strings B. The part ‘Il preferably projects lat erally outwardly from the lower side of the neck III at the projection 20, as illustrated in Figs. 1 and 2 of the drawings. In practice the part l0 may be of substantial width and the part is pref erably curvedor bowed, being curved laterally outwardy and in the direction of the body portion Il. The curved surface 8| thus presented by the part 80 forms an eii’ective rest or means for lo cating the player’s fingers with respect to the 20 strings B and the neck. 'I'he invention contem plates the forming of the part 80 integral with the neck I 0 or as a separable member attached to the neck I0. In the simple case illustrated in the drawings the part 80 has one end attached 25 to the projection 2l by pins or screws l2 and has an arm or lug I3 on its other end secured to the under side of the neck by a pin or screw Il. Where the part GII is a separable member it may be formed of sheet stock such as sheet aluminum 30 and the lug 82 may be twisted to properly engage against the neck I0. A transverse slot or notch 2i is provided in the upper side of the neck Il to receive or carry the pick-up unit C. The notch 2i is adjacent the 35 inner end of the neck I0 being spaced inwardly a considerable distance from the projection 20. The portion of the neck In provided with the opening or notch 2| may be solid or without the groove I5, as illustrated in Fig. 6 of the drawings 40 and may be thickened as at 22. - The key box portion or the peg box portion II of the body A integrally Joins the inner end of the neck I0 and is provided to carry the keys or pegs 23 for tensioning the strings B. The portion 45 I I of the body A may be substantially rectangular in its general configuration having slightly in wardly converging sides 24. The portion II is preferably hollow and provided with an internal space or'cavity 2l which may be open at the 50 under side of the portion II. A central longi tudinal web 28 extends through the interior or cavity 25 of the body portion I I and a transverse bridge or web 21 connects the forward or outer portion of the web 28 with the sides 24. rI'he upper wall 28 of the portion Il is provided with spaced openings or slots 29 for receiving the strings B. It is a feature of the invention that the body portion II just described is angularly related to the neck I Il. 'I'he key box portion or 60 peg box portion II extends downwardy and in wardly from the inner end of the neck III as clearly illustrated in Fig. 2 of the drawings. 'I‘his position or formation of the body portion II pro vides for the proper positioning of the neck I0 65 and the easy fingering of the strings B when the body portion I2 is supported against the shoulder of the player. The above described relationship between the neck I0 and the body portion II assures the comfortable engagement of the body 70 portion I2 or the shoulder pad (not shown) on the portion I2 with the shoulder of the player while the neck I0 is properly elevated in playing position. The invention provides improved means for 75 8,180,174 3 very accurately tuning the strings B by finely material to influence the pick-up unit C. Bpaced regulating the tension of the strings. Adjustinß openings 35 are provided in the outer end portion or regulating units U are provided onthe key .of the body neck Il to receive the end portions box portion IlA of thebody A for eñecting the of the strings B. Suitable nuts, spools'or the fine accurate adjustment of the tension on the like are provided on the strings B to cooperate strings B. Fig. 4 of the drawings illustrates one with the openings 35 to hold the strings against of these units U in detail. Each unit U includes movement in one direction. The strings B pass a plate 13 attached to the upper face oi' the body over a bridge 35 at the~outer end of the ñnger portion II by screws 1I or the like. The plates l board I5. A bridge 31 is provided at the inner end oi' the finger board I6 and the strings B 10 10 of the units U are disposed below and trans versely of the strings B. A block 12 is arranged extend inwardly over the bridge 31 to be in the on one end part of each block 10 and screws 13 proper spaced relation- to the finger board I5. secure the blocks 12 to the plates 13. The screws The bridge 35 is preferably integral with the one 13 project from the upper sides of the blocks 12 piece body A while the bridge 31 may be inserted and are provided with heads 14. The units U in and secured in a notch 35. It is to be under include tiltable or pivotable plates 15 arranged on stood that bridges of various characters may be the blocks 12. The screws 13 freely pass through employed on the instrument if desired. The openings 15 in the plates 15 to pivotally support upper or active string supporting edges oi' the or retain the plates 15. The heads 14 of the bridges 35 and 31 are arcuate and support the screws 13 limit the pivotal movement of the plates strings B in spaced relation in a curved or arcu 15 and prevent the displacement of the plates. ate series to be in their proper relation to the surface I1 of the finger board I5. The usual Each plate 15 carries means for engaging or bear ing on a string B. In the simple form of the notches may be provided in the bridges 35 and invention illustrated a slotted screw 11 projects 31 to maintain the strings B in their proper positions. The strings B extend inwardly from 25 from the upper side of each plate 15 and the the bridge 31 to pass through the slots 23 into string B passes through its slot as clearly illus trated in Fig. 4 of the drawings. ‘An adjusting the cavity 25 of the body portion II. The end screw 13 is threaded through an opening in each plate 15 and its inner end is adapted to engage or 30 bear against the fixed plate 10. In practice the ends of the adjusting screws 18 may be suitably rounded and may cooperate with correspondingly shaped recesses 19 in the plates 10. Knurled 10 15 20 25 portions of the strings B are wound on the keys or pegs 23 whereby the strings may be tightened ' 30 and tuned by means of the pegs 23. The pick-up unit C is operable to convert the actual tone producing vibrations of the strings B into pulsations or modulations in an ampli fying circuit 40. The pick-up unit C is such that heads 30 may be provided on the adjusting screws 13 to facilitate the accurate manual adjustment the intensity, frequency, etc. of the sound pro 35 of the screws. Means is provided for preventing _ ducing vibrations of the strings B act through swinging or turning of the plates 15. Pins BI project from the plates 15 and extend into open ings 32 preventing undesirable lateral swinging of 40 the adjustable plates 15. The plates 15 are posi tioned or set to exert an upward force on the strings B or to form bridges on which the strings bear. ’I'he screws 13 may be threaded or turned to react against the fixed plates 10 and thus pivot 45 -or adjust the bridge plates 15. By carefully turning or adjusting the screws 15 the tension on the vibratory strings B may be very accurately regulated as desired. The units U are very com pact and are light in weight. The portion I2 is provided on the inner end of 50 the body A for engaging the shoulder and chin of the player or for carrying a suitable shoulder pad (not shown) for engaging the shoulder or for carrying a chin rest (not shown) for cooper 55 ating with the chin of the player. The shoulder engaging portion I2 of the body A projects later ally in one direction from the inner end of the portion A. 'I'he rear or inner side 30 of the por tion I2 is curved forwardly to join its forward 60 face. The upper and lower faces of the portion I2 may be substantially horizontal or substan tially parallel with the plane of the longitudinal axis of the neck III. In accordance with the in vention the portion I2 is preferably hollow hav 65 ing an internal cavity 3i. The upper side of the cavity 3I is closed by an integral wall 32 of the body A while the lower side of the cavity 3l is closed by a plate 33 cemented or otherwise fixed in position. 'I'he strings B are strung across the finger 70 board I6 of the neck III between the outer end portion I3 of the neck and the body portion II. In accordance with the usual practice there are four strings B of graduated diameters. lThe 75 strings B are formed of steel or other magnetic the medium of a magnetic field to modulate the . amplifying circuit 40 in a proportional or definite manner so that the amplifying circuit 40 is influ enced to faithfully and accurately reproduce the 40 sound. In accordance with the invention the pick-up unit C includes a magnet or a magnet assembly comprising a pair of like opposed mag nets 4I. It is a feature of the present invention that the magnets 4I are permanent magnets as 45 distinguished from electro-magnets which might influence the amplifying circuit 4I! to produce a hum or other undesirable sound. The magnets 4I are substantially U-shaped in their general configuration, each having two spaced arms 42 50 and 43. The magnets 4l are arranged in the opening or notch 2I so that their lower arms 42 rest or bear on the inner wall of the notch. In the preferred construction the magnets 4I are proportioned to project from the opposite 55 sides of the neck I0 to be of sufficient length to insure the proper operation of the unit C. In accordance with the invention the magnets 4I are arranged in opposed relation, that is, the confronting or opposed ends of their arms 42 and 60 43 have opposite polarity as indicated in Fig. 5 of the drawings. This provides a continuous state of polarity at the opposite sides of the assembly of magnets. It is preferred that the confronting or opposed ends of the arms 42 and 65 43 of the magnets 4I be in spaced relation. The upper or outer arms 43 of the magnets 4I are formed or shaped to have the proper rela tionship to the arcuate series of vibratory strings B. The inner end portions 43'L of the magnet 70 arms 43 are curved upwardly and inwardly to extend over the arcuate series of strings B and be substantially equally spaced from the strings. The several strings BB thus influence or añect the proper zone of the magnetic ñeld of the magnet 75 4, 2,180,174 assembly 4|-4|. >The invention provides a sim "ple and particularly effective means for securing the pick-up unit C to the body A and for dampen ing the magnets 4| to prevent vibration of their arms. Screws 44 are passed through openings 45 in the neck I8 and extend through openings 48 in the lower arms 42 of the magnets 4|. The upper ends of the screws 44 engage or bear against the under sides of the inner portions 48' of the 10 magnet arms 43. This engagement of the screws 44 with the- arms 48 prevents vibratory movement of the arms which might produce a ringing sound. The screws 44 are preferably of non-magnetic material so that -they do not short out or affect 15 the magnets 4|_. ' . The magnets 4| arranged or mounted as Just described have the portions 48n or their upper arms 48 passing over or above the strings B in spaced relation to the strings. Thus the strings 20 B pass through the lines of force of the magnetic field and when vibrated vary the density of the magnetic flux. The magnets 4| may be carefully adjusted or set when 'assembled on the body A to be in the proper relation to the strings B. The 25 pick-up unit C provides or includes a coil 48 ar the neck I0 and is electrically connected with the outer winding of the coil 48. The other lead or conductor 52 extending to the amplifying circuit 40 is electrically connected with one of the mag nets 4|., A post or member 58 bearing on the lower arm 42 of this magnet engages-the inner windings of the coil 48 to complete the circuit through the coil. The enamel on the inner wind ings ofthe coil 48 is removed where they engage the said member 58. 'The posts or members 88 operate to carry the stronger lines of the mag netic force into the center of the field of the coil 48. The strings B pass between the ends of the members 58 and the >magnet arms 48 vary the density of or disturb the lines of force of the mag 15 netic assembly and thus set up or induce an elec trical circuit in the coll 48 picked up from the magnetic field. . . The coil 48 of the pick-up unit C is electrically connected to the amplifying circuit 48 which 20 may also be a speaker or sound reproducing unit. Thus variations in the density oi' the magnetic flux picked up by the field of the coil 48 are con verted into sound. This sound reproduced iby the amplifying and sound reproducing circuit 48 ranged within the magnet assembly 4|-4|. The is a true reproduction of the sounds or tones pro coil 48 is arranged on the inner or lower arms 42 duced by the vibratory strings B. It is to be understood that any suitable form of amplifying of the magnets 4| and operates to pick up or receive an electrical current from the field of the 30 magnet assembly. The coil 48 is wound on a coil form or spool 48 of the proper configuration. The coil 48 constitutes a winding of suitable enameled wire of the proper gauge trained or ~Wound on the spool 49 between its end flanges. The spool 49 is preferably formed of a suitable non-magnetic in sulating material and has openings 49ß receiving the screws 44 whereby the screws operate to hold the coil in place. It will be understood that the number of turns on the coil 48 and the gauge of 40 the wire forming the coil depend upon the par ticular amplifying circuit 40 with which the in strument is to be used. The coil C positioned within the assembly of the magnets 4| is located between the north and south poles of the magnet 45 assembly and is related to the strings B to be ail‘ected by their vibration. The upper side of the coil spool 49 is spaced some distance below the arcuate series of strings B and disturbances in the magnetic field or ñux of the magnets 4| resulting 50 from vibration of the strings B induces an electric current in the coil 48. The pick-up unit C includes a plurality of core members 50 for attracting the lines of magnetic force toward the center of the coil 48. The mem 55 bers 58 are in the nature of pins or posts pro jecting from the upper side of the coil spool 49. The lower ends of the members 58 preferably en gage the lower arms 42 of the magnets 4|. In accordance with the invention the upper ends of 60 the members 50 are spaced below or inwardly from the strings 'B there being one member 5U spaced from each vstring B. The post members 50 of the coil project dill'erent distances from the and sound reproducing device or unit may be em ployed in connection with the pick-up unit C and 30 that the typical unit 40 illustrated in the drawings is not to be construed as limiting the scope or application of the invention. The invention includes means for conveniently associating or connecting the coil 48 of the unit ('5v 35 on the portable musical instrument with an am plifying and sound reproducing unit such as the circuit 40. In the preferred _structure illustrated in the drawings a socket or jack 53 is arranged in an opening in the forward wall of the inner por tion I2 of the body A. The Jack 58 projects into 40 the cavity 3| of the body portion | 2. The _jack 58 is adapted to receive a plug 54 connected with the leads or conductors 55 from the amplifying cir cuit 40. The conductors 5| and 52 extend through the opening or cavity 25 of the body portion || 45 and pass through an opening 58 in the body to ex tend into the cavity 8|. 'I'he invention includes means for varying the amplification of the sound. A volume control is provided on the instrument or violin in a position to be conveniently accessible to the artist or player. 'I'he lines or conductors 5| and 52 extend through the cavity 8| to the jack 58, and the amplifying control or volume control may bein the form of a variable resistance ele 55 ment or rheostat 58 arranged in the cavity 8| and interposed or connected in the conductors 5| and 52. The control handle or knob 58 of the volume control or rheostat 58 projects from the curved inner surface 88 of the body portion I2 where it is conveniently accessible to the artist or player. In playing the instrument the body A is held or positioned with the portion |2 resting or bearing spool 49 so that the spaces between their upper against the shoulder and with the neck I8 en ends and the strings B are graduated substantially in proportion to the graduation in diameter of the strings. This spacing or relationship between gaged by the finger hand of the player. It is to be 65 understood, of course, that the portion'l2 of the instrument body A may be provided with the proper shoulder pad (not shown) and chin rest the upper ends of the coil members 5l) and the strings B operates to compensate for differences in the degree of variation of the magnetic reluctance or variation in the magnetic reluctance when the strings are vibrated due to the differences in the diameter of the strings. One lead or conductor 5| from the amplifying 75. circuit 48 extends through a suitable opening in (not shown). As the center of greatest mass and the center of gravity of the instrument is adjacent 70 its inner end the instrument is readily supported or held in this manner. It is to be particularly noted that the neck I0 is very light in weight and does not carry or support any heavy or cumber~ some parts. The neck l0 terminates at its outer 2,180,174 end in the portion Il which merely carries tbe 5 having a iinger board, a plurality of »need ten dead or ilxed ends of the strings B.v This stub sioned vibratory strings extending overthe' iinger ment is in the proper playing position imposes the neck having its poles at opposite sides of the strings, the magnet comprisingspaced. arms, a coil between the poles of the magnet positioned so that the strings pass between it and the ad neck I0 is tubular or hollow and when the instru- ' board. in spaced relation thereto, a magnet 'on little or no weight on the artist's hand which fingers the strings B. The arranging or locating of the keys or pegs 28 in the portion I i of the body A removes the weight of the pegs and the neces sary relatively heavy body portions for carrying 10 the keys from the outer end of the neck which is the position they usually occupy in a typical violin. A typical bow is drawn over the strings B be tween the unit C and the bridge l1 or at any other point adjacent the unit C -to cause vibration of the strings. Vibration of the strings by the bow or by plucking results in variations or disturb ances in the magnetic ñeld to induce a current in the coil 4l. The current of the coil Il is ampli fied by the circuit 40 and converted into a repro 20 duction of the sound of the instrument by the cir cuit 40 and its associated parts. It will be obvious that the vibratory strings B influencing or dis ‘ turbing the magnetic flux adjacent or above the post members 50 of the coil 4l induces a current 25 in the coil 48 having the frequencies and other characteristics of the vibrations of the strings to accurately or proportionately influence the cir cuit 40. The amplifying and sound reproducing circuit 40 receiving these pulsations or modula 30 tions faithfully produces the sound produced by the strings B, which sound has all the tonal qual ities of the sound of the strings. The volume of the sound produced or reproduced by the circuit lll may be easily and conveniently controlled »by the artist or player by turning the knob 49. It is to be noted that the electrical musical instru ment of the present invention operata to amplify the true tones produced by the vibratory strings without vibration of any other physical parts of the instrument proper. The instrument or violin comprising the single one-piece body A formed of light material and provided with the openings and cavities described above is extremely light and is very compact. The 45 instrument does not involve any sounding parts or resonant boxes. The neck I0 and the portions Ii and I2 of the body are proportioned and re lated so that the instrument may be easily and conveniently handled by the player or artist and 50 the relationship of the parts is such that the neck I0 and ñngerboard I8 are properly positioned for playing when the body portion i! is supported on the shoulder. - Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the speciilc details here in set forth, but wish to reserve to myself any var iations or modifications that may appear to those skilled in the art or fall within the scope of the following claims: ' Having described my invention, I claim: l. In an electrical stringed instrument a neck having a ringer board, a plurality of spaced ten sioned vibratory strings extending over the finger board in spaced relation thereto, a magnet on the neck having its poles at opposite sides of the` strings, the magnet comprising spaced arms, a coil between the poles of the magnet positioned so that the strings pass between it and the ad 70 jacent arms of the magnet, the coil being oper able to convert the ñux of the magnet into a current which is modulated by vibration of the strings, and means for dampening the arms of the magnet to prevent vibration thereof. 76 2. In an electrical stringed instnunent a neck jacent arms of the magnet, the coil being oper- ' able to convert the flux of the magnet into a current which is modulated by vibration of the 10 strings, and means for dampening the arms of the magnet to prevent vibration thereof, said means including securing members engaging said arms and securing the magnet and coil to the 15 neck. 3. In an electrical stringed instrument a neck having a finger board, a plurality of spaced ten sioned vibratory strings extending over the nnger board in spaced relation thereto and arranged in an arcuate series, a magnet on the neck having 20 its poles at opposite sides of the strings, the mag net comprising inner arms and outer arms, the outer arms being arcuately curved to follow gen erally the curvature of the series oi’ strings, and a coil between the poles of the magnet positioned 25 so that the strings pass between it and the ad jacent arms, the coil being operable to convert the flux oi' the magnet into a current which is puisated by vibration of the strings. 4. In an electrical stringed instrumenta neck 30 having a convex ñngerboard, a plurality of spaced tensioned vibratory strings extending over the fingerboard in spaced relation thereto and ar ranged in an arcuate series, a magnet on the neck having its poles at opposite sides of the strings, the magnet comprising inner arms and outer arms, the outer arms being arcuately curved to follow'generally the curvature of the series of strings, a coil between the poles of the magnet positioned so that the strings pass be 40 tween it and the adjacent arms, and core mem bers projecting from the coil toward the strings, the spacing of the members from the adjacent strings being substantially uniform. 5. In a stringed musical instrument having a 45 body and a plurality of spaced tensioned strings extending across the body in spaced relation thereto, a pick-up unit comprising a pair of op posing magnets on the body, each magnet having an arm above the strings and an arm below the 5.0 strings, an induction coil in the ñeld of the mag nets operable to convert the flux of the magnets into a current that is modulated by vibration of the strings, and screws passing through open ings in the body, the lower arms of the magnets 55 and the coil to secure the magnets and coil to the body and engaging the upper arms of the magnets to prevent vibration of the same. 6. In a stringed musical instrument having a body and a plurality of spaced tensioned strings extending across the body in spaced relation thereto, the strings being graduated in diameter and being arranged in an arcuate series, a pick up unit on the body comprising a pair of mag nets each having an arm spaced below the series 65 of strings and an arm spaced above the series of strings, the last mentioned arms being curved to follow generally the curvature oi' the arcuate series of strings, an induction coil between the upper and lower arms of the magnet positioned so that the strings pass between it and the upper magnet arms, and core members projecting from the coil toward the upper magnet arms and each having an upper end spaced from a string, the spaces between the upper ends of the core mem 75 i 6 2,130,174 bers and the adjacent strings being substantially uniform but graduated substantially in propor tion to the graduation in diameter of the strings to compensate for dinerences in the extent of variation o1’ the magnetic ilux by vibration of the graduated strings. ’1. In a stringed musical instrument having a » body and a plurality of spaced tensioned strings extending across the body in spaced relation 10 thereto the strings being arranged in an arcuate series, a pick-up unit on the body comprising a pair o! opposed U-shaped permanent magnets each having an arm spaced below the series of strings and an arm spaced above the series ot strings, the magnet arms projecting laterally be yond the opposite sides of the series of strings, the upper arms of the magnets having substan tially straight outer portions and having inner portions curved to substantially conform to the 5 curvature of the arcuate series of strings. an induction coil in the ileld of the magnets, and core members'projecting from the coil toward the strings whereby the vibratory strings Pals through fields in which the lines o't magnetic 10 force converge toward the outer ends of the cors members. GEORGE D. BEAUCHAMP.