US1838833A - Agraffe - Google Patents

Description

Dec. 29, 1931. v G. E. HOLMBERG 1,838,833

AGRAFFE Filed June 2'7. 1930 Patented Dec. 29, 1931 UNITEDSTATES P E "OFFICE GUS E. HOLMBERQOF nocxroan, ILLINOIS, ASSIGNOR To SOHUMANN rIANO m "T V PANY, or nooxrom), ILLINOIS, A CORPORATION OF ILLINOIS Application filed June 127 -My invention relates too improved means for limiting the amplitude of vibration of piano strings and has particular reference t. to a new and improved typeof agraife.

In the manufacture of pianos it is essentialthat the strings be held firmly against the bridge of the piano. This has been customarily accomplished through the provision of a plurality of pins slightly stag- Io gered with respect to the direction of the string, the string passing'on opposite sides of adjacent pins in contact with the bridge whereby a lateral bend is formed in the taut string. This construction not only serves to 1.3 secure the string to the bridge wherebyvvibrations are transmitted to the sounding board. but acts to'relieve a portion of the tension on the hitch pins. Various other devices have been provided for the purpose of 1 securing the string to the bridge but none of them have.,until now, proved to be entirely satisfactory, with the result that, at the present time, substantially the entire industry still employ the old fashioned bridge pin.

2.. Some of these devices are so designed as to' be in contact with the strings over a considerable length thereof which is undesirable in that it results in a bulky I construction.

- Other devices consist of a number of pieces which are costly to manufacture and difiicult to properly secure in position upon the bridge. Some of the agralfes have failed to eliminate the side strain. on they bridge and sounding board. Still others have been so designed that they become loosened after the instrumenthas been in service a short periodof time, thusmaterially affecting the tone of the piano. Other. agrafl'es impart a me- "tallic color to the tone of the piano.

a I have aimed to provide a one-piece agraffe which maybe manufactured at a cost substantially lower than has heretofore been possible. I

' Another object of the invention isthe provision of an agraffe which has contact'with the strings of the piano over -only a very short distance. e

I'have also aimed to provide an agraffe' which will not becomelooseupon the bridge 1 'and'a structure to hold threejstrings.

1930. Serial No. 464,144." f'

should thesecuring means become slightly loosened therefrom. w

r A still further object of the invention is the provision of an agrafle wherein the ten: sion'of the string on theb'ridge is downward as in the case of aviolin and nohorizontal tension is applied thereto.

I'have also aimed to provide an agraife having improved means for positioning the same upon the bridge.

Another object of the invention is the provisionof an agrafi'e ofa so-called dead material whereby a metallic tone is notimparted to the string. 7 V

A further object of the invention is the provision of an agrafie having improved means .for rapidly securing the strings therein. 'Other objects and attendant advantages will become apparent to those skilled in the art from the following description and the accompanying drawings in which- Figure 1 is a vertical section through the plate, pin. plank, bridge, and sounding board of a rand piano embodying my improved agra e; I

Fig. 2 is an enlarged view of the agrafle portion of the bridge as'shown in Fig. 1; V Fig. 3 is a perspective view of the agrafl'e showing means for securing 1, 2, and 3 strings therein; 1

4 is a front view and Fig. 5 is a rear View of the modification adapted to hold a single string; and 7 Figs. '6 and 7 are front and rear views, respectively,. of the modification adapted to hold 3'st'rings. t

Figure 8 shows anothermodification of a Referring first to 'Figure 1, a section is shown through aconventional grand piano having the usual plate 10, pin plank- 1'1, lining members 12 and 13, and sounding board 14. A conventional bridge 15, .is secured to the top of the sounding board 14 in the usual mannerfStrings 16 are connected atone end to-hitch pins 17 secured in the back member 18of the plate 10 and at their forward ends to tuning pins 19 passing threugh the 100 plate 10 and frictionally secured in the pin plank 11, the strings being drawn to the clesired tension by rotation of the tuning pins. A ridge 20 is positioned on the upper side of the back member 18 forward of the hitch pins 17 so that the strings 16 will bear against this ridge when drawn taut. A felt layer 21 is positioned between the strings and the ridge 20 to prevent a metallic quality from being transmitted to the strings. At the forward end of the strings 16 near the tuning pins 19 the former pass over a mute bar 22, a felt pad 23 being provided between the plate 10 and the strings to prevent audible vibration thereof. The customary Capo D-Astro bar 24 is positioned above the strings 16 slightly to the rear of the mute bar 22 and projects downward to a lower horizontal level than the upper edge of the mute bar so that when drawn taut the strings 16 will be caused to pass through an angle at the point of contact with the mute bar.

The structure so far described is intended to be merely that of a conventional grand piano, which would ordinarily be provided with a series of pins on the upper surface of the bridge 15 to connect the strings to the bridge and stop the vibrations thereof. 1 have, however, arranged to provide an agraffe shown more in detail in Figs. 3 to 7, which may be formed from a single piece of socalled dead material, that is, material which will not impart a metallic characteristic to the tone of the strings. I have found that the agrafl'e may advantageously be formed from sheet brass, or bronze, whereby the desired tonal characteristics are obtained.

The agrafie is formed from a single piece of metal to provide a flat portion 25 adapted to be secured to the'top of the bridge 15 by means of a screw 26 passing through an opening 27 therein. Formed integral with the fiat portion 24 is a V-shaped portion 28 provi ding a front side wall 29 and a rear side wall 30. It is desirable that the angle between the side walls 29 and 30 be as small as practicable in order to reduce to a minimum the lengthof contact between the strings 16 and the agratfe. The wall 29 of the agrafi'e is of such length as to project downward slightly beyond the plane of the flat portion 25 and is provided with a locating tip 31 intermediate the ends of the lower edge thereof. In positioning the agrafl'e upon the bridge 15 the locating tip 31 is placed over a previously located and marked. point and. is forced into the wood of the bridge as shown in Figs. 2 and 3, by in sertion of the screw 26 at a marked point, until the lower edge of the wall 29 comes in contactwith the bridge. It will be seen that since the lower edge of the wall 29 lies in a lower plane than the flat portion 25 it will be necessary to spring the metal of the agra'lfe slightly in order to bring the flat portion 25 in contact with the bridge 15 throughout the entire area of its lower surface. Thus the entire agraife is placed under a slight upward pressure whereby, should the screw 26 become slightly loosened through seasoning of the bridge 15 the agraife will not become loose upon the bridge, but will merely spring upward slightly against the head of the screw 26.

The tip 31 serves a plurality of purposes. It serves as a locating point to indicate, in connection with the screw opening 27, the proper position of the agraffe. The tip also prevents the agrafle from turning with the screw when the latter is being inserted. It also permits the front wall to be held stationary so that the spring action may be exerted on the screw. It further prevents lat eral movement of the agraitle.

Each of the agralfes may have one, two, or three openings 32, 33, and 34:, in the rear side wall 30 thereof to accommodate one, two or three piano strings therein in the manner shown in Figure 2. These openings pass through the wall. 30 at right angles thereto and, where more than one is provided, in a plane parallel to the flat portion 25 as shown in Figs. 6, 7 and 3. The front wall 29 of each agrail'e is provided with either one, two or three openings 35, 36, and 37, similar to the openings 32, 33 and 3 1, in the rear side wall 30 but located in a substantially higher plane than the openings 32, and 34, whereby a string 16 when passing through an opening in the wall 30 and a corresponding opening in the wall 29, will be bent through a vertical angle at the side wall 29 and at the side wall 30. Thus corresponding openings in the side walls 29 and 30 lie in the same vertical plane but not in the same horizontal plane.

In order to permit a string to be inserted in the agraffe without threading it endwise through an opening, I have provided slots which lead to the openings whereby the string may be moved transversely of its length through the slot and into the opening and whereby the string will be held firmly in the opening when drawn taut. Thus in Figs. 3, 4i, and 5, wherein a single opening is provided in the wall 30 and a single opening 35 is provided in the wall 29, a slot 38 serves to connect the openings 32 and 35, passing through the unction of the two walls 29 and 30. Thus a single string may be passed through the slot 33 transversely of its length and be caused to engage the openings 32 and 35, as shown in Figs. 2 and 3. On the other hand where the agratfe is to support two strings, two openings 32 and 34, are provided in. the side wall 30 and two openings and 37 in the side wall. 29. Slots 39, 40, 4-1 and d2, are provided in the side edges of the walls 30 and 29, respectively, permitting one string to be inserted. into the openings 32 and through the slots 39 and 41 and a second string to be inserted into the openings 34 and 7 37 through the slots and 42, respectively.

If desired,the slots to the two pairs of openings may be formed through thejunction between the walls 29 and 30 as shown in Figure 8, which structure will likewise permit the strings to be moved into the desired openings. Where three strings are to be positioned in the agrafle in three pairs of openings, theopenings 33 and 36 shown in Figure 7 6, may be provided which require the string to be threaded endwise through the agraffe or alternatively the structure shown in Figure 8 may be employed whereby the string may be moved into the openings transversely. Thus in Figure 8 all three strings may be secured in the agrafi'ewithout being threaded into the opening endwise, while in the modification shown in Figs. 6 and 7, one of the strings must be threaded through the openings 33 and 36 endwise.

Figure 3 shows the three agraifes which may advantageously be employed in a piano. The one containing the single pair of openings is adapted to be employed for the base strings of the instrument where only a single string is employed for the production of a single tone. The agrafi'e shown at the cen ter of this figure is that adapted to hold two strings which are employed for the intermediate strings of the piano in which two strings are employed to produce a single tone. The agrafle shown at the right is that adapted to hold three strings normally employed to produce a single tone in the higher register of a piano. v

The manifold advantages of my improved construction will, doubtless, have become apparent. The agrafi'e is formed from a single piece of sheet material by the ordinary stamping and formingprocesses whereby the cost of manufacture thereof is relatively small. The two walls of the agrafie serve to securely hold the strings of the instrument at closely spaced points and do not permit of movement thereof whereby only a small amount of space onthe bridge is taken up and the string remains at the desired pitch over a longer period of time than would otherwise be the case.

The tension of the string on thebridge is downward and no lateral twisting strain is imparted thereto as is the case where stag gered bridge pins are employed. Because of this the bridge is not placed under a lateral tension from the great multiplicity of strings secured thereto and consequently is free to displace the agraffe.

- Theagrafi'eis.placedluponthebridge under a slight gtension whereby eventual loosening ofathe 'screwldue to theseasoningiof the wood inithe bridge' 'merely permits the agrafle to spring baclr slightly, thus preventing the same from becoming loose on the bridge and impairingthetone of the instrument} vTheagralfe is formed from a so-cal'led dea material which=does notimpart a character;

.istic colortothe toneof the instrument and consequently does not require to be paddedor mufiledas is the case when steelor similar materialseare employed. 1

-I--Iliave thus described andilliistratedwa specific embodimentof my invention and I am; aware that numerous alterations and changes maybe made therein without materially departing from the spirit of the invention and the scope of the appended claims inwhich i r '51 claim v .Ini aone-piece agraffe the combination of a front and arear wall in. the form of an inverted V, the legs of; which form integral rear' 'and front-walls, means for attaching said agrafi e to the bridge of aipiano, the

bottonrfree .ends of each of said walls being adapted-tobear against the bridge of a piano, each of said walls having thre'e'openings and slotsconnecting therewith to permit spaced strings to be inserted therein by movement transversely of -its length, two of saidslots extending from the junction of said walls to an opening in each. Wall to permit the central string tobe inserted through such transver'semovemen't, said openings lying in different horizontal planes whereby said string, when taut, will have a downward pressure on one of said walls and an upward pressure on the other of said walls.

2. The combination in an agrafle arranged to be positioned on the bridge of a piano to support the strings thereof, of a front and a rear wall positioned transversely of said bridge, said front wall having a tip on the lower'edge thereof adapted to be pressed into said bridge to prevent movement of said wall with respect thereto, and a substantially fiat portion integral with said rear wall for securing said agrafi'e to said bridge.

' 3. The combination in an agrafie arranged to be positioned on the bridge of a piano to support the strings thereof, of a rear wall,

a portion projectingoutward from the'lower end. of said wall integral therewith, having an opening to receive a screw for securing said agrafi'e to said bridge, a front wall integral with said rear wall, a tip on the lower edge of said front wall adapted to be inserted into said bridge, said front wall being of greater length than said rear wall, whereby insertion of said tip and said screw in said bridge will cause said agrafl'e to be brought against said bridge under a tension to prevent said agrafie from becoming loose thereon when said screw becomes slightly loosened.

4. An agrafie arranged to support the strings of a piano upon the bridge thereof comprising a single piece of sheet metal having bends providing a fiat portion adapted to receive a screw to'secure the portion against said bridge, an upwardly bent rear wall adjacent thereto and a downwardly bent front wall, said walls having openings at different horizontal levels to receive at least one string of a piano.

5. In an agraffe a one-piece body of sheet metal having a fiat portion provided with an opening for the reception of a screw for securing the agralfe to the bridge of a piano, said body being bent upwardly to provide a rear wall and thence bent downwardly to provide a front wall, each of said walls having at least one opening and a slot connecting therewith to permit a string to be inserted therein by movement transversely of its length, said openings lying in different horizontal planes whereby said string, when taut, will have a downward pressure on one of said walls and an upward pressure on the other of said walls.

6. An agrafl'e as described in claim 5 in which the lower end of the front wall extends to a lower plane than the lower surface of said flat portion whereby the agrafi'e is placed under tension when the agrafi'e is placed upon a flat surface and the flat portion is drawn tightly down.

In witness of the foregoing I afiix my signature.

GUS E. HOLMBE-RG.

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