US1525343A - Method of manufacturing sounding boards for musical instruments - Google Patents

Description

Patented Feb. 3, 1925.

UNITED STATES JAMES FREDERICK VEACO, OF BERKELEY, CALIFORNIA.

METHOD OF MANUFACTURING SOUNDING BOARDS FO'R MUSICAL INSTRUMENTS.

Application filed October 22, 1921. Serial No. 509,555.

which the following is a specification, in such full and clear terms as will enable" those skilled in the art to construct and use thesame.

This invention relates to a method of making sounding boards for musical instruments and its object is to lighten the load on such sounding boards.

A further object of the invention is to lighten the weight of the sounding board and to improve the tone.

A further object of the invention is to make the sounding board stronger and to give it a better and more permanent crown, while at the same time making it more responsive to the string vibrations, whereby a rounder and fuller tone is produced.

A further object of the invention is to pro duce an initial strain in the sounding board which will render the tone better than the ordinary sounding board.

Other objects of the invention will appear as the description proceeds.

An embodiment of the invention is shown in the accompanying drawings in which the same reference numeral is applied to the same portion throughout, but I am aware that there may be modifications thereof.

Fig. 1 is a side elevation of the apparatus used in the manufacture of the sounding board.

Fig. 2 is a side elevation of the apparatus used in the manufacture of the sounding board looking in right angles of Figure 1.

Fig. 3 is a side elevation, and

Fig. 4 a plan view of one of the clamps for holding one of the ribs during the stretching operations.

lFig. 5 is a side elevation and Fig. 6 a plan view of one of the clamps used at the opposite end of the ribs.

Fig. 7 is a view of the spring used for measuring the tension applied to the ribs during the stretching operations, and

Fig. 8 is a side elevation of the sounding board after it has been released from the press, showing the crown formed by the stretching of the ribs.

In producing a sounding board for musiclamps 0 cal instruments by this method, the sounding board is laid fiat upon any suitable table. The ribs are then stretched nearly to their breaking point, whereupon they are glued permanently to the sounding board. A suitable apparatus is applied to them to hold them tightly against the sounding board until the glue has had time to set, after which the strain on the ribs is released, and the sounding board may be removed from the table upon which it was laid, whereupon the contraction of the ribs causes the board to be bent concave on the side the ribs are applied to, and owing to the initial stretching given the ribs they will always retain the crown on the sounding board, since the crowning is due not to the bending of the ribs themselves which may in time cause a permanent set in them, but to the stretching of the material which immediately places the sounding board itself in a state of compression as soon as the stretching of the ribs is released. The apparatus used consists of a pair of sawhorses 1 andiZ upon which a plurality of are placed. These clamps consist of heavy plates with upturned ends having open slots as indicated at 4, such a number of the clamps is used as may be required, the number being dependent entirely upon the size and stiffness required in the sounding board.

These clamps are loosely laid upon the sawhorses so that they may be moved to any desired position, and upon them is loosely placed a. heavy fiat board 5 which forms the table upon which'the sounding board 6 is laid.

Yokes Tin such number as may be desired are secured to the edge of the board 5, and each yoke is provided with a screw 8, the ob ject being to hold three or more beams 9 down against the ribs 10 while the glue is in process of setting, ordinarily requiring 18 to 24 hours.

A clamp 11 having two prongs 12 and 13 to embrace one end of the rib is used at one end of each of the ribs. This clamp has a yoke 14 surrounding its prongs 12 and 13, and a screw 15 is used to tighten the prongs against the rib to hold it rigidly. This clamp also has side lugs 16 and 17 which engage the sides of the bars 3 adjacent the slots 4.

A somewhat similar clamp 18 is used at the other end of the ribs. It has two prongs 19 and 20 which embrace thewends of {the 1? ribs, whilea yoke 21 with a set screwQQ at tords the means for tightening the prongs 19 and 20 on the ribs: This clamp also has a threaded end 23 with a nut 24 thereon for placing-a strain on the ribs;

A washer 25 is placed on the threaded rod end 23 and bears upon' a heavy spring 26;

the object beingto provide means whereby a given-load maybe appliedto eachrib by measuring the "compression of each of the several springs :used;

When the sounding board hasbeen placed on the table 5," the :ribs are placed thereon; the'clampsll and 18 are applied andihe desired pressure is app'liedtoeach ofthe ribs,

whereupon the glue is'applied to the under side'iof the ribs and the screws 8 are operated to tighten the cross ,beams9 down against theiri-b's to hold them tightly in place until the gluehas been set. When the glue has set-between"tl1e ribs and sounding board thecla'mpsmay be released and the ends of the. ribs may; then be cut off 'the desired length whereupon the sounding board will be bent as'illustrated iii-Figure 8 with the. V ribs on :the concave. side.

In' practicerit has been found that it is possible to make ordinary piano sounding boards crown sufficiently by using from SIX to tenribs;ea'chotwhich is strained up to about. eight hundred pounds before being gluedittast to the board;

This refers to ribs about three-eighths of an 'inch'lthick and oneinchlwide. If heavier ribsyare' used the'cinitial'strain must be increasedaccordingly; The actual amountof lengthening-10f the ribs under the given strain is comparatively small [for when the.

elastic limit is reached the'rib is likely. to break with the application of very little additional stress; The wood'used maybe of any kind at present used in-sounding boards;

butfsomexspeciesof fir is most commonly usedfor'the' ribs. The sounding boards are usually made-up of several widthsof board of the desired character glued together to produce a board of the. desired width."

, stretching the ribs longitudinally, securing" the ribs rigidly tozthe sounding board, and

thenrele'asingjthe strain upon the-ribs.

2." A method of producing soundingboards for musical instruments wh ch coinpi lSES' placing the sounding board upon a suitable surface; )lacing the;1ibs'tl1e-reon,' stretching the ribs, rigidly 'securing the 'ribs to 'thei' sounding board," and thereafter releasing the 'ribs from the stretchingapparatus and1i'cut--i ting them the'desired length:

3. A method of producing sounding boards" for 'muslcalx instruments Wlll'Cll i comprises placingthe sounding board upon a suitable support," placing the" ribs on the soundlngboard, stretching the ribs as maybe desired} gluing the .ribs to the. sounding board, se-

curing the ribs rigidly against movement until the glue has seems thereafter releasing theribsand "cutting them the "desired length:

board ina stretched condition; and *then re Inoving'the strain from=the ribswhereby the board is permanently crowned;

5. A method'ol reducing sounding boards for musical lnstrum'en-ts" which consists 1H1 stretching the ribs,'-secu'ringthemarigidly to the board throughout'the'ir length'while they V are "stretchd, andthen removing :the strain from the ribs whereby the-board iscrownedf In testin'ionywhereof I have hereunto; set

my hand this ll'thr 'day of october 'A.--D;

JAMES FREDERICK vEAoo.

Witness FRANKLiN S Bu'oxrlr'n' method of producing sounding boards for musical lnStI11lI1eI1t'S"Wl1'1Cl1' consists-1n stretchingth'e 'r1bs.-secur1ng them to the

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