US558619A - Bridge for musical instruments - Google Patents

Description

(No Model.)

- G. R. STEBBINS.

BRIDGE FOR MUSICAL INSTRUMENTS.

Patented Apr. 21, 1896.

UNITED STATES PATENT EEICE,

GEORGE STEBBINS, OF ROCHESTER, NElV YORK.

BRIDGE FOR MUSICAL INSTRUMENTS.

SPECIFICATION forming part of Letters Patent NO. 558,619, dated April 21, 1896.

Application filed January 11, 1896. Serial No. 575,162. (No model.)

To all whom it ntay concern.-

Be it known that I, GEORGE E. STEBBINS, of Rochester, in the county of Monroe and State of New York, have invented a new and useful Improvement in Bridges for Musical Instruments, which improvement is fully set forth in the followin g specification and shown in the accompanying drawings.

Stringed musical instru1nents such as mandolins, guitars, violins, zit-hers, banjos, &c.are each provided with a bridge near one end and a nut near the other end, upon which to hold and suspend the strings over the finger-board and the body of the instrument. The bridge and the nut of these instruments as usually made are respectively straight, narrow, or slender strips of wood, metal, or other material placed parallel with each other and at right angles with the axis of the finger-board. lVhen any string thus suspended on the bridge and the nut is caused to vibrate by suitable means, it produces a musical sound known in music as an open note. This open note is the lowest note the string is capable of producing in any given case, the vibration of the string being along its entire length between the rests on the bridge and the nut. To produce higher notes or tones, the string is stopped by the finger by pressing it firmly against the finger-board, the vibration being then only between the bridge and the finger thus placed, which shorter length of vibrating string will give a higher tone. Some of these instruments are provided with frets upon which to make the stops, these frets being slender strips of metal or other material secured to the face of the finger-board or some part of the instrument beneath the strings. The frets are placed parallel with the nut, and when a string is pressed by the finger against one of them the fret for the moment acts in the same capac ity as the nut, the vibrations of the string being intercepted by it. The frets are relatively so spaced that when a string is pressed against either one the string will, when vibrated, produce a note one-half tone higher or lower than if pressed against the adjacent fret below or above it. In consequence of this the tone produced at the twelfth fret-stop will be an octave above the open note, the twelfth fret being placed equidistant from the nut and the bridge. Furthermore, if the fin ger be brought to only delicately touch the string midway between the bridge and the nutthat is to say, over the twelfth fret-- the string when vibrated will produce a harmonic note or tone, which will be, or should be theoretically, as to pitch, equivalent to the tone given by the string when pressed firmly against the fret or fully stopped; but here is found a difficulty in music. The harmonic tone and the twelfth-fret full-stop tone do not agree as to pitch. The harmonic tone is the true one, and it becomes at once a standard of comparison for the stop-tone, which is almost universally untrue or sharp. Also a similar inharmony occurs between other harmonic notes and the fullstop notes of the frets over which the harmonics are made as, for instance, the fifth, seventh, and others.

To remedy this difficulty is the object of my invention, the latter relating rather more cspeciallyto fretted instruments in which the stops for the strings are arbitrary. In case an instrument is not fretted-as the violin, for examplethe stops are not arbitrary and may be varied in any case by slightly shifting the finger. By this means every tone produced by stopping may be corrected according to the accurately-trained ear of the performer; but the necessity for such corrections exists when such instruments are used with straight bridges or such as are commonly employed, and my invention applies also to these. This sharping of the twelfthfret stop-tones (and this is more or less true of all the stop-tones) is caused mainlyby the increased tension of the string resulting from bending the latter out of a right line when forcing it aside or down against the fingerboard. Some of the strings of these instruments are larger and heavier, and consequentlystiffer, than others, and to force these against the finger-board requires a greater pressure of the finger. On account of this the tones produced by them are sharp, substantially in proportion to the weight or stiffness of the string, and to compensate for this sharpness of the tones 1 form the bridge irregularly to give the heavier strings an increased length over that of the lighter strings, proportioning this added length to the different weights or sizes of the strings. By giving the bridge this corrected form the twelfth-fret stop-tone will be accurately an octave above the tone of the open string, or so nearly so as not to be objectionable, and it will also coincide as to pitch with the harmonic tone over that fret.

Referring to the drawings, the Figures 1 to 4, inclusive, show successively the strings and some relative parts of a mandolin, a zither, a banjo, and a guitar. Fig. 5 shows a crosssection 011 the dotted line 5 5 in Fig. 4, and Fig. 6 shows a simple modification of the bearings of the strings.

Referring to the parts shown, A is a portion of the body of a mandolin, B the fin ger-board, and a the nut. The strings Z) rest upon the nut and the bridge O, the rests 0 upon the bridge being out of a straight line or offset forward or back of each other, as shown, so as to give the strings different lengths of suspension between their bearing-points on the bridge and the nut. This irregularity or crookedness of the line of the bearings of the strings upon the bridge is made for the purpose of correcting the stop-tones of the instrument, as above described, the heavier strings being given the greater length.

In Fig. l the two inner pairs of strings have rests upon the bridge in a line at right angles with the axis of the linger-board, while the outer pairs of strings (on either side) are respectively longer and shorter than the intermediate pairs. As the tension of the strings of the two inner pairs is about equal when pressed against the fin gerboard, those strings require about the same length of suspension; but the tension of the other strings varying they are given different lengths correspondingly.

In case of the zither, as shown in Fig. 2, the two A strings, which are equal, have rests upon the bridge C in line, while the rests of the other strings drop back successively, as shown, according to the weight and the tension of those strings. In this form of bridge the line of the rests of the strings thereon is not parallel with the nut, (not shown,) but irregularly divergent therefrom.

In case of the fretted banjo, ban jorine, and other like instruments, parts of which are shown in Fig. 3, the rests for the strings upon the bridge C are thrown forward or back aeeording to the size and kind of the string.

As to the guitar, (shown in part in Fig. 4,) the bass-strings E, A, D are comparatively heavy wound strings, the E string being the heaviest and D the lightest of the three. On account of this the rest for said E string upon the bridge D is thrown back, while the rest for the D string is thrown forward of that of the A string, the length of each string being proportioned to its weight and tension. As to the other strings, G, B, E, they also run from heavy to light in the order named and are given lengths according to their weight and tension; but as a whole the three lastnamed strings are lighter than the three first-named strings and are correspondingly shorter'that is to say, the bass-string E is heavier than the G string and is consequently longer; but the G string is heavier than the bass D, for example, the latter being conse quently shorter.

hen the bearings for the strings upon the bridge are in a straight line as bridges have been heretofore constructed, the open strings of an instrument are all of a length, and no compensation is provided for the differences in tension and consequent errors in pitch of tone. IVith my improved bridge these matters are provided for and the stop-tones correeted.

In many of these instruments the high part or ridge (1, upon which the strings bear, is a slender wire or strip of metal secured to or let into the wooden portion of the bridge, as shown in Fig. 5. It is not essential, however, that this bridge-wire should. be a continuous, irregular, or sinuous piece, as shown in Figs. 1 to at. It maybe divided trans\'*ersely, as shown in Fig. 6, each string havin a separate or independent rest upon the bridge E, and the bridge maybe divided itself transversely into as many small bridges as there are strings, if found convenient, each string having an independent bridge.

\Vhat I claim as my invention is 1. A bridge for a stringed musical instrument, having the bearings for the strings thereon formed forward or back of one another, each bearing being immovable and the whole bridge in a single piece, substantially as described and shown.

2. In combination with the nut and the frets of a stringed musical instrument, a bridge having immovable bearings for the strings, the bridge being in a single piece and the line of the string-bearings being irregular and out of parallel with the parts, sub stantially as specified.

In witness whereof I have hereunto set my hand, this 6th day of January, 1890, in the presence of two subscribing witnesses.

GEORGE E. STEBBINS. \Vitnesses:

Enos B. WHrrMonE, M. L. WINsToN.

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