US2316800A

US2316800A - Stringed musical instrument

Info

Publication number: US2316800A
Application number: US410813A
Authority: US
Inventors: John W Mcbride
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-09-15
Filing date: 1941-09-15
Publication date: 1943-04-20
Anticipated expiration: 1960-04-20

Description

April 20, 1943.

J. W. MGBRIDE STRINGED MUSICAL INSTRUMENT Filed Sept. l5, 1941 3 Sheets-Sheet l A muunni April 20, 1943- J. w. MCBRlDE 2,316,800

STRINGED MUS ICAL INSTRUMENT Filed Sept, `l5, 1941 3 Sheets-Sheet 2 7X do n. M65/7b? @Wmv ATTORNEY April 2o, 1943. J. w. vmamma v.2,316,800

STRINGED MUSICAL INSTRUMENT Filed Sept. l5, 1941 3 Sheets-Sheet 3 INVENTOR ./an iff/Vc fy'a ATTORNEY Patented Apr. 20, 1943 UNITED 'STATES PATENT OFFICE Claims.

This invention relates to a stringed musical instrument, and more particularly to an instrument in which the pitch of the musical sound caused by vibration of any of the strings is capable of being determined by determining the free length of vibration of the string. This process is accomplished usually by stopping the string against a surface by the nger of the player.

This application is a continuation in part of an application filed in the name of John W. McBride on April 14, 1941, bearing Serial No. 388,379, and entitled Stringed musical instrument.

Such stopping is commonly employed in playing such instruments as a guitar or violin, in

I which the neck oi the instrument forms a convenient surface against which the string being played can be pressed by the linger,

In view of the fact that the fingers may be required to be piaced over the strings at any point along the strings, prociency in playing such an instrument is dependent upon manual and digital dexterity.

It is one of the objects of this invention to make it possible to control or adjust the free length of the vibrating string in a more convenient manner, and without the necessity of materially shifting the position of the hand.

In order to accomplish these results, use is made of an elongated rod arranged beneath the string to be controlled, and extending generally in the direction of the string. The rod has a series of longitudinally spaced teeth, formed by an interrupted crest that progresses angularly about the longitudinal axis of the rod, in a helical-like manner. By adjustment of the rod about a longitudinal axis, the string is caused to rest upon any desired tooth or point of the interrupted crest, and its free length of vibration is thus determined. The rotation of this rod to cause the teeth or crest to assume the desired positions is accomplished by depressing linger keys. Accordingly, it is another object of this invention to provide a mechanism under the control of the ngers of the player, for rotation of a string stopping bar or rod of this character.

The invention possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of a few embodiments of the invention. For this purpose there are shown several forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of this invention is best dened by the appended claims.

Referring to the drawings:

Figure 1 is a plan view of a musical instrument incorporating the invention;

Fig. 2 is an enlarged part sectional view, taken along plane 2-2 of Fig. 1, a part of the instrument being omitted to reduce the size of the iigure;

Figs. 3, 4 and 5, are sectional views on a further enlarged scale, taken along. correspondingly numbered planes of Fig. 2;

Figs. 6 and 7 are sectional views as seen on correspondingly numbered planes of Fig. 4;

Fig, 8 is a pictorial View of a finger key adapted to be used in the instrument incorporating the invention;

Fig. 9 is a pictorial View of one of the elements utilized in connection with the keys;

Fig. 10 is a fragmentary detail elevation of one form of rod used for determining the free length of a vibrating string;

Fig. 11 is a cross sectional view on an enlarged scale as seen on plane lI-II of Fig. 10;

Figs. 12 and 13 are views similar to Fig. 10, showing modiiied forms of rods; and

Fig. 14 is a detail cross section as seen on plane |4-I4 of Fig. 14. In the present instance, the invention is shown as incorporated in a guitar, although it s capable of being utilized with many types of stringed musical instrument. Instead of utilizing a hollow resonant body, to set up or augment the sound vibrations, the instrument is shown as capable of being connected with appropriate electrical amplifying apparatus. For this purpose the body I (Figs. 1 and 2) of the guitar is shown as made of solid wood or other appropriate material. Extending from the-body l is the elongated neck portion 2. This neck portion terminates in the flat peg board 3. In the present instance, a four string guitar is illustrated, the four strings being designated respectively by the

reference characters

4, 5, 6 and l.

For maintaining these strings under tension, a bridge member 8 (Fig. 2) may be appropriately supported adjacent the end of the body portion l. This bridge is located in the recess 3l formed in the top of body I. This bridge member 8 is provided with a series of apertures 9, and each aperture may be provided with a rearwardly extending enlarged portion I0. These apertures 9 serve as anchoring apertures for the strings.

Each of the strings for example may be provided with an enlarged ball end The strings may be passed through the respective apertures 9, the ball being accommodated in the enlarged portion l5. The ball being larger than the aperture 9, it engages the edge of the aperture 5, the tension on the strings may be exerted.

The board 3 may be provided with the posts or pegs l2, I3, l and I5, serving as anchors for the free ends of the strings. These posts may be arranged to be rotated as desired by the thumb pieces i5, to wind the strings upon the posts.

The strings are stretched under tension so that they are in Contact with two separated points. The pitch of the note caused by free vibration between these points is a function of the mass per unit length of the string, 'and the tension. Shortening of the free vibrating length of the string causes an increase in pitch. All this is well understood. The bridge 5 has an upper surface upon which the right hand ends of the strings rest. Therefore the edge of this bridge S forms one of the stationary points.

The peg board 3 forms an abrupt shoulder I9 (Fig. 6) with the neck 2. At this portion of the neck 2, there is a metal bracket having a vertical wall I3 which is disposed against the shoulder i9. This bracket is appropriately fastened to the top surface of the neck 2. The vertical Wall |8 is provided at its upper edge with a series of slots 2li (Figs. 4 and 6). The strings slope downwardly along board 3. They contact the bottom surfaces of these slots. As will be described hereinafter, the free or open position of the strings is determined not by the slots 2U, but by a device hereinafter to be described, and operating to form stops for the strings at some point to the right of bracket I1.

As in the usual guitar, the neck member 2 may be provided with a plate 2| carrying the graduated marks i2 and underlying the

strings

4, 5, 6 and l. Its left hand edge as shown most clearly in Figs. 3, 5 and 6, may abut the right hand edge of the bracket l'i.

As most 'clearly illustrated in Fig. 2, the bridge 8 may be concealed beneath a sheet metal cover member 22. This cover member 22 is shown as having a depending wall 23 extending downward over the edge of the body l. Conveniently this right hand edge of the body may be provided with a recess so as to permit the depending member 25 to lie flush with the body i. This cover member 22 may be secured as by the aid of the screws 24.

At its front edge the cover member 22 may be provided with a stepped portion 25 connected as by the sloping connection 25 with the main part of the cover member. This portion 25 is disposed so as to be flush with the top surface of body i. Through connection 25 there are clearance apertures 27 to permit free passage of the strings. An anchor for this end of the cover piece 22 may be provided by the aid of a strap 28 fastened to the lower side of extension 25 and having a slot 29 therein. This slotted end is intended to be passed underneath the head of a screw Si) located in the bottom of the cut-out space 3|.

The vibrations of the strings li, 5, 6 and are intended to aiect an electro-magnetic pickup device indicated diagrammatically by the reference character 32. The strings are shown in this instance as passing directly above th'e pickup device 32. Leads from this device may extend through aperture 0| (Fig. l) to the exterior of the instrument.

In the conventional playing of a guitar, the fingers of the left hand are used to stop the

strings

4, 5, 6 and 'I against the neck. In accordance with the present invention, the ngers are utilized to depress the closely spaced finger buttons or

keys

33, 3d, 35 and 36 (Figs. l, 5 and 8), located near the end of the neck. Thus the hand does not have to be movedl from the end position, and accordingly extreme manual dexterity is no longer essential.

The manner in which these buttons control the free length of the strings will now be described in connection with the string 5 (Fig. 6). The mechanisms for the other strings are quite similar and will be described only insofar as they may differ in detail from the mechanism associated with string 5.

Located beneath the string 5 is a rotatable rod 3l (Figs. 2, 3, 4, 5 and 5). Its axis of rotation is substantially parallel to the string. At its right hand end this rod is provided with a stub shaft portion 35 journaled in a bracket 39 (Fig. 2). This bracket 59 overli'es the vertical wall (i0 formed in the body member and located at the right hand end of the hollowed-out portion 4| of the body i. VThe left hand portion of rod 37 carries the extension 42 (Figs. 5 and 6) that is journaled in the vertical wall |8 of the bracket i'i. This rod Si, as shown most clearly in Figs. 10 and il, is provided with a series of teeth |22 formed by the interrupted crest Yof a helical-like ridge s3. This ridge G3 progresses angularly along the longitudinal axis of the rod 37.

As clearly shown in Fig. 1l, this ridge 43 is not high enough to contact the string with which the interrupted crest is intended to cooperate. The teeth or crests |22 however are high enough so that they will contact successively the bottom surface of string 5 as the rod is turned about its axis. The longitudinal spacing of teeth |22 agrees with the spacing of the frets or graduations |2|, on the finger board 2 i, as shown in Fig. 1. Thus, as the rod 3i is turned clockwise as viewed in Fig. 3, successive teeth |22 will engage string 5 and progressively shorten its eiective length. By referring to Fig. l1 it will be noted that teeth |22 are separated by equal angular distances, accordingly the pitch angle of ridge 43 and the teeth thereon increases toward the right as the length of the string 5 is shortened. Thus equal angular movements of rod 31 and hence equal movements of operating key 35 are effective at any point of the scale to tune the string to successive notes. This has some advantages in promoting ease of playing. Furthermore, each tooth |22 has an angular extent slightly greater than the angular separation of the teeth, so that successive teeth overlay by a small amount. In this way, the string is never released between engagement by successive teeth, andthere is no possibility of an annoying uping caused by thefaces of the teeth engaging thestring.

With the teeth |22 disposed in planes normal to the axis of rotation as in the form of Fig. 10, the pitch of the note emitted by the string is not dependent on the exact angular position of the particular tooth engaging the string. Itis obvious that the eiective length of the string and hence the Vnote will be the same regardless of whether the center or one or the other edgeV portions of the tooth engages the string.

It may be desirable lto make it possible to vary the pitch of the note slightly by a small movement of the operating key. This may be readily accomplished by inclining the teeth with respect to the corresponding plane of rotation. Such an arrangement is shown in Fig. 12. Therein a rod |24 substantially the same as rod 31 is provided with teeth |25 arranged on a helicallike ridge |26 as before. These teeth |25 are inclined with respect to their planes oi rotation and may be equiangularly spaced and arranged to overlap slightly.

. It will be apparent that the eiective length of the string will depend on what point of the particular toothengaging the string is contacted, whether near the center or adjacent one end or the other.

In Figs. 13 and 14, a rod |21, similar to rod 31 is shown, but on which the ridge |23 is a true helix. Thus the teeth |29 thereon are separated by angular distances which vary with the longitudinal spacing of the teeth. The angular extent of the teeth |29 varies in accordance with this angular spacing, so that successive teeth overlap slightly as before. With the teeth arranged in this manner, the angular movement of the rod, as well as the movement of the corresponding operating key becomes progressively less as the pitch becomes higher in a manner analogous with the closer spacing of the frets. Thus, for successively higher notes, the amount of movement of the key 35 as it rotates the rod to tune the string becomes less and less, as will be apparent from the following description of the key mechanism.

The finger key 35 is associated with the rod 31 so that pressure exerted on this key inwardly, as by one of the lingers of the left hand of the player, will cause the rod to be rotated. The extent of the depression of the key in the direction transverse to the neck 2 determines the angular position of the rod 31, and the corresponding position of the point along the ridge 43 which is in contact with string 5.

Key 35 is shown to best advantage in Figs. 5, 6 and 8. It is guided for movement transverse of the instrument in a manner now to be described. Thus the key 35 has a lower portion 44. The lower surface of this portion 44 rests upon the bottom of a square-cut slot 45 in the bracket |1. This slot 45 is undercut at the ieit hand edge, there being an overhanging iiange 46 as shown most clearly in Fig. 6. The lower portion 44 is provided with the projecting side flanges 41 and 48. The left hand ange 48 is accommodated beneath the projecting edge 46. The right hand iange 41 is overlaid by a detachable stop piece 45. This piece is shown to best advantage in Fig. 9. It is screwed to the bottom of the bracket |1 as by the aid oi screws accommodated in the apertures By this means the key 35 is guided for transverse movement. A rack 5| is arranged on portion 44. This rack is adapted to engage the pinion 52 mounted on the rod 31.

V As shown most clearly in Figs. 5 and 6, this pinion 52 is attached to the reduced portion 42 of the rod 31 and abuts a shoulder formed between this reduced portion 42 and an enlarged portion 53. The rod 31 is constantly urged and in a resilient manner in a counterclockwise direction by the aid of a helical spring 54 disposed over the extension 42. The right hand end oi this spring is anchored in a collar 55 that abuts the pinion 52. It is provided with a set screw 56 whereby the angular position of the collar 55 may be adjusted. At the leit'hand end of the extension 42 there is a collar 51 which is free to rotate on the extension 42 and to which is anchored the left hand end of the spring 54. This collar is arranged to be angularly adjustable within the sleeve 53 shown as formed integral with the wall |8 of bracket |1. The collar 51 may be maintained in adjusted position as by the aid of the set screw 59.

Thus in order to adjust the tension of the spring 54, either one or both of the

collars

55 or 51 may be appropriately rotated and maintained in adjusted position.

The constant force urging the shaft 42 and rod 31 in a counterclockwise direction causes the key 35 to be urged upwardly as viewed in Fig. 5. A stop is provided to limit this upward movement at the point where the rod 31 assumes the position of Fig. 5. For this purpose the plate 49 (Fig. 9) is utilized. This plate 49 has the projecting edges 69 and 6|. The projecting edge 69 is arranged to overlie the iiange 41. As shown most clearly in Fig. 8, the flange 41 is cut back at the iinger engaging end of the button 35 to accommodate the extension 65. In this way a shoulder 62 is formed on the key 35 which is urged against the extension 60 when the key 35 is released.

The ,

other keys

33, 34 and 35 similarly control the positions of

bars

53, 64 and 55. The axes of all of the bars are parallel; `and all of the

keys

33, 34, 35 and 35 are placed compactly adjacent @the end of the neck portion 2. In this way the fingers or the left hand may be readily utilized without movement of the hand as a whole along the neck of the instrument.

Thus for example the rod B5 controlling the free length of string 4 carries the pinion 66 (Figs. 5 and 6). This pinion 66 is displaced in an axial direction from the pinion 52, but in other respects the mechanism is entirely similar to that already described. The extension 6| of stop plate 49 operates against the corresponding abutment on the lower portion of key 35. The torsion spring |02 in this case is somewhat longer than the spring 54.

Similarly the button 34 operates the rod 64. In this case the pinion 61 is spaced tow-ard the left of fthe pinion 52. Accordingly, torsion spring |03 is somewhat shorter than spring 54.

The button 33 controlling the position of the rod 63 serves to rotate the pinion 68. In this case the pinion 68, as shown most clearly in Figs. 5 and 6, is arranged adjacent the left hand extremity of the reduced extension 59. An intermediate bearing standard 10 is provided for this extension 59. Within the bearing standard is the angularly adjustable collar 1l. The torsion spring 12 has its left hand end anchored to the collar 1| (Fig. 7). Its right hand end is anchored to the angularly adjustable collar 13 placed at the right hand end of the extension 69. Furthermore, in order to provide stops against upward movement oi the

keys

33 and 34 as viewed in Fig. 5, stop member 14 (of the same structure as stop 49) is utilized.

The rack and pinion mechanisms are provided with a cover member 15 (Figs. 1, 2, 3, 4, 6 and 7.) This cover member as shown most clearly in Figs. 4 and 6, has a notched flange 15 overlying the top edge of wall i8. At the opposite edge it has a flange 11 disposed slightly to the left of the left hand edges of the

bars

31, 63, 64 and B5. Furthermore, the cover 15 has an end wall 18 (Fig. 5) having depending flanges 19 and 80,

which are continuations respectively of the flanges 'i6 and 17. These anges 'I9 and '80 serve to support the cover 15 in a pivotal manner. rIhus the flange 79 (Fig. 5) carries the pin shaft 8l engaging in an apertured ear 82 formed as an extension of the wall I3. The opposite flange 80 is arranged to overlie the threaded ear Y83. This threaded ear is engaged by the screw 84 that serves as a pivot shaft for flange 8U. The cover 75 may thus be swung up on these supports, to expose the ringer key mechanism and to permit adjustments to be made.

As shown most clearly in Figs. '4, 6 'and '8, the top portion 85 of each of the nger keys or

Vbuttons

33, 34, 35 and 36 is arranged to telescope underneath the cover 15. This top portion may be provided with a series of marks 8&5 to serve las a guide for the player in determining how far the buttons must be pressed inwardly to secure a definite pitch. These marks are adapted to cooperate with the open edge 8l (Fig. el) at the right hand side of the cover I5. The cover T5 may also be provided with spring vlingers 88 located between the

finger keys

33, 311, 35, S5, and adapted to snap over corresponding spring finger extensions 89 formed integrally with the bracket I1. These spring fingers serve detachably to re strain movement of cover 'i5 about the axis of pin 8| and screw Sli.

Control of the volume of the impulses transmitted through the pickup mechanism 32 is conveniently accomplished by the aid of a Variable resistance 9i embodied in the neck 2 of the instrument. Thus leads '96 (Figsf2 and 3) extend from device 32 through an elongated aperture 92 in the instrument which leads to the chamber 93, in which is mounted the resistance '9 t.

The variable resistance 9i is controlled optionally by lever S5 or 95, depending on whether the instrument is slung from the players neck and supported by the aid of the left hand or whether the instrument is resting on the players lap.

The guitar, as suggested hereinabove, may be supported as by the aid of a sling hung around the neck. In this event the sling may be Vanchored to a button Iii arranged at the yend of the body Alternatively, it may be supported in the lap of the player.

To guard against possibility of any of the

strings

4, 5, 6 or 'i rattling in their respective supporting notches 253, a damping member |30 is provided to engage the strings. As clearly shown in Figs. 6 and '7, a light metal channel iti extending across the cover i5 is mounted on the under side of the cover, and a rubber strip i3d is cemented therein. The parts are so arranged that this strip exerts a slight downward pressure against each of

strings

4, 5, 5 and 1.

What is claimed is:

l. In a stringed musical instrument, means for tensioning a string between two i'lxed points, and means for adjusting the free length of the string, comprising a rotatable rod having means forming a plurality of axially as well las -angularly spaced teeth for successively engaging the string.

2. In a stringed musical instrument, means for tensioning a string between two xed points, and means for adjusting the free length of the string, comprising a rotatable rod havingV means forming a plurality of teeth for successively engaging the string, said teeth being disposed in a helical-like row on the rod.

3. In a stringed musical instrument, means for tensioning a string between two xed points, Vand means for adjusting the free length of the lstring in definite steps in accordance with va musical scale, comprising a rotatable rod with a 'plurality of teeth thereon, for engaging the string, 'Said teeth being arranged in helical-like formation, and means for lrotating the rod.

4. In a stringed musical instrument, means fo'r tensioning a string between two iixed points, and means vfor adjusting the free length of the string in definite steps in accordance with a musical scale, comprising a rotatable rod with a plurality of teeth thereon, for engaging the string, said teeth being arranged in helical-like formation, the pitch angle of said helix varying progressively, whereby a constant increment `of angular mbation of the rod serves to tune the string for successive notes of said scale.

5. In a stringed musical instrument, means for tensioning a string between two fixed points, and means for adjusting the free length of the string in denite steps in accordance with a musical scale, comprising a rotatable rod with a plurality of teeth theeon, for engaging the string, said teeth being arranged in helical-like formation, the pitch angle of said helix being constant, whereby the amount of angular movement imparted to the rod to tune the string to successive notes of said scale varies with the pitch of the note.

6. In a stringed musical instrument, means for tensioning a string between two xed points, means for adjusting the free length of the string in steps in accordance with a musical scale, said means comprising a rotatable rod having teeth thereon for successively engaging the string, said teeth being inclined with respect to a plane nora mal to the axis of the bar, whereby angular movement oi the bar alters the free length 'o'fthe string so that the string may be tuned in lex'- act accord with said scale.

'7. A bar for use in tuning a tensioned string comprising a helical-like crest so disposed as to clear the string and teeth arranged along the crest and extending transversely thereof for engaging the string.

8. A bar for use in tuning a tensioned 'string comprising a helical-like crest so disposed as to clear the string and teeth arranged along the crest and extending transversely thereof for en-Y gaging the string, said teeth being axially spaced in accordance with a musical scale.

9. In a stringed musical instrument, means *forl tensioning a lstring between two fixed points, means for adjusting the free length oi the 'string comprising a rotatable bar having an interrupted crest extending transversely of the axis of the bar, and means for rotating the bar to bring a desired portion of the crest into engagement with the string, said crest at the point of engagement dening one limit for the said free length.

10. In a stringed musical instrument, means for tensioning a string between two iixed points, means for adjusting the free length vof the string comprising a rotatable bar having an interrupted crest extending transversely of the axis of the bar, and means for rotating the bar to bring a desired portion of the crest into engagement with the string, said means comprising a pinion secured to the bar, a rack slidably supported for cooperation with the pinion, a nger key adapted to urge the rack in one direction, and means resiliently opposing such movement of thejrack.

JOHN W. MCBRIDE.