US1690925A - Pianoforte - Google Patents

Description

Nov. 6, 1928.

R. H. COLLEN PIANOFORTE I Ticrfia.

ROBERT H.COLLE.N

@2123 atiw 71W.

INVENTOR Patented Nov. 6, 1928.

ROBERT HENRY coLLEN, or EAST HAM, ENGLAND, ASSIGNOR or ONE-HALF T JOHN BROADWOODxQ; SONS LIMITED, LONDON, ENGLAND.

mANoroR'rn.

Application filed November 29, 1926, Serial No.

This invention'relates to the means against which the strings of the pianoforte bear and which determine the active or vibratory length of the said strings, some of the said means being situated on the bridge, or

bridges. and constitute also the means by,

which thevibrations of the said strings are transmitted through the said bridge, or bridges to the sound-board of the instrumen[-, p

The means adjacentthe wrest ortuning pins has usually consisted of a number of studs screwed into the metal-frame and the wrest plank secured thereto, there being one stud for each note which may consist of one, two, or three strings. Formed on'the upper side of the head of each ofthe said studs are two parallel upstanding pieces, through one of which are bored one, two, or three holes in accordance with the number of strings required for the particular note. The strings constituting 'the note pass from their re- 7 spective wrest, or tuning, pins through the holes in the said upstanding piece and over 5 the other upstandingpiece (which is slightly higher than are the holes in the first men tioned piece) and are led therefrom to be tween pins on the bridge, or one of the bridges, from which they are then passed through and secured to the hitch bins. The length of the string between the upstanding piece over which the said string passes and the first of the pins on the bridge with which the said string engages constitutes the vibratory portion of the said string and it is essential that the said vibratory portion of each string that passes over the samestud shall be of the same length. To effect this it is essential that the upstandingpieces on 40 the studs upon which the strings bearbe at right angles to the runof the strings thereon, and this-"requirement combined with the necessity of screwing upthe studs tightly into the metal-frame has hitherto presented 45, practical difliculties, as,howevertrue the dimensions of the stud and its threads may be, it is impossible to screw all the studs home tightly With the upstanding part at the re-. quired angle without straining and thereby weakening the saidstuds, which in some known instances have been weakened to such an extent that they broke" when the'strings were put intension. a

' The pins'hitherto employed on the bridge, or bridges, between which the strings pass said bridge, or bridges,

151,438, and in Great Britain January 4, 1926.

and bear as aforesaid are arranged in pairs transversely across the said bridge, or bridges, the pins of each pair being so arranged relatively theme to the other that i a string passed between them is bent in such manner that, whenin tension, it bears with great side-way pressure on the inner part of each pin and it also bears with great downward pressure on the said bridge due to its being on a higher plane thanthe metal frame. The. accumulative side-way pressure on all the'pins on the bridge, or bridges, tends to bend, or warp, the said bridge, 'or bridges, in a plane parallel with the plane of the sound-board which tendency is counteracted only by the adhension of the said bridge, or bridges, to the sound-board and the accumulative downward pressure on the tends to bend it, or them, in a plane at right angles to the plane of the sound-board, which tendency is transmitted to the sound-board.

' This invention has for its object to provide improved devices for use in substitution for the aforesaid studs adjacent the wrest, or tuning, pins which can be easily secured to themetal-fra me and which devices can be readily turned into the required position to bring the parts thereof upon which the string, or strings, bears, or bear, in proper angular position relatively to the said string, or strings, the devices being if desired, of such form that the liability of straining 7 present with the studs hitherto employed is entirely eliminated, the said devices being also eminently suitable for use in substitution for the pins hitherto employed on the bridge, or bridges, on the soundboard of the instrument and these may also, if desired be of such form thatthe aforesaid stresses and strains to which the bridge, or bridges, and sound-board are subjected are also eliminated.

According tothis invention the devices consist of a number of bearing blocks each ad aptedto be turned upon and to be secured by a screw which passes freely therethrough and is screwed into the metal-frame in the same, or approximately the same,'position as the studs hitherto employed, or is screwed into the bridge, or bridges, on the soundboard so that the block is in a position analogous to the position of the pairs of pins hitherto used on the said bridge, or bridges. The block is provided with bearno ing parts against which a string, or strings, bears, or bear. the height of the parts against which the string, or strings, actually bears, or bear, being preferably such that when in tension the said string, or strings, exerts, or exert, pressure in opposite directions that is, towards and away from the plane of the metal-frame, so that the pressure in onedirection neutralizes. or substantially neutralizes, the pressure in the other direction. Each block is adapted. similarly to the aforesaid studs hitherto used, to accommodate either one, two, or three, strings in accord-- ance with the number of strings required to constitute a note. By securing each of the blocks by a screw which is distinct and separate therefrom the angular position of the said block relatively to the string, or strings, bearing thereon. can be easily adjusted by simply turning the said block on the said screw which may then be tightly screwed so as to clamp the base of the said block between its head and the en ace into which is screwed. After the bea; n-g block has been adjusted to the required position: it may, if desired. be; held against subsequent move mentby an additional screw.

I will describe this invention with referenceto the accompanying drawings in which Figure 1 shows. in transverse section, so much of the back, inetal-iraine and soundboard of a yertical-pianoiorte as is necessary to illustrate the application thereto of examples of bearing blocks for the strings in accordance with this invention. Figures 2, 3 and 4: shew in vertical sect-ion, front elevation and horizontal section, respectively, one form of bearing blocl; for use for notes requiring three strings which is adapted to be held in position by two screws the second of which is inserted when the required angular position of the said block has been determined, the sa d block being also shewn by way of example applied to the )ridge of the pianotorte shewn'in Figure 1. Figures 5 and 6 shew in elevations at right angles to each other a modified term of bearing bloclt which is adapted for use for notes requiring two strings.

As hercinbefore ment oned each 01' the strings has hitherto been led from a stud, or the equivalent, on the metal-fra1ne to between a pair of pins on the bridge of the sound-board from which it is then led to and fixed to a hitch pin secured to the said metalframe, the pins of each pair of pins being so arranged, relatively the one to the other, that a str ng passed between theniis bent transversely and bears, when in tension, with great side-way pressure on the inner part of each pin. besides bearing: with great pres sure on the said bridge, and these pressures are transmitted to the sound-board and cause it to bend or warp if not strongly braced. The employment of bearing blocks (such for example as the bearing blocks A shown in Figure 1 of the accompanying drawings) on the bridge. or bridges, of the pianoiiorte entirely eliminates the aforesaid side-way pressures on the said bridge, or bridges, each of the str' when in tension pass in a stra ghtpa.. iron'i the tuning p ns to the hitch pins and consequently there is no liability of the sound-board to bend or warp.

"-t immaterial whether the bearing on the bridge, or bridges. are of the re OZ'UL or construction. as those on the metal-frame B or not; in Figure 1 the bearing block A on the badge E is shewn, by

of example, as being that shown sepaely in Figures 2, 3 and 4 and hereinafter 'zcribed. desired, movement of the bearing blocks. after they have been set in position by one screw, as hereiubefore described, may be preyentec by an additional screw. Figures n to 5, illustrate two examples oi bearing blocks n each of which provision is made for the additional securing screw.

In the form of bearing blocl: shown in Figures 2. 3 and l; the base 3 has formed longitudinall -J thereon two upstanding pieces 11 and 11 provided at their outer ends with pins 12 and '13 which pass transversely rhriuigh and projectbeyond the outer sides of the said upstanding pieces. Passing transversely through and projecting beyond the sides of the upstanding piece 11 is an intermediate pin 14: and in alignment with the said pin is a short pin 1 which passes transversely through the upstanding piece 11 and projects from the outer side only of the said upstanding piece. Gountersunk holes s and a are formed in the base 3 between the upstanding pieces 11 and 11 for the insertion of two screws (shown at a and a in Figure 1) one of which is inserted before the other and after the block has been turned on the first inserted screw into the desired angular position relatively to the strings. the other screw is then inserted and maintains the said block in position. This form of bearing block is more especially suitable for use for three strings and these can be easily and quickly applied by simply leading two of the strings from their tuning pins over the outwardly projecting ends of the pin 19, under the outwardly projecting ends of the pins 14 andll and over the outwardly projecting ends of the pinl3, whilst the th rd string can be applied by leading it from its tuning pin, over the portion of the pin 12 between the upstanding pieces 11 and 11, under the inwardly projecting end of the pin let (there being sufficient space be- I side of the upstanding piece 11 to permit of passed therebetween) and then over the portion of the pin 13 between the said upstanding pieces.

on the end of the said pin and the inner Figures 5 and 6 shew a modified form of bearing block to that last described which is adapted for use for two strings. 'In this modified form the base3 has only one longitudinal upstanding piece 11 formed on its t base 3 through which piece transverse pins l2, l3 and let project from each side thereof. Countersunk holes 4 and 4, one on each side of the upstanding piece 11, are formed in the base 3 for the reception of the securing screws one of which is inserted after the said block has been set in position as in the last described form of block. v

In the hereinbefore examples of bearing blocks described and shown with reference pensed with thereby rendering it capable of vibrating more freelythan hitherto and in consequence thereof the resonance and tone of the instrument is greatly increased.

hat I claim is 1. A bearing block comprising a base, two

upstanding pieces disposed longitudinally of said base and two pins passing transversely through and projecting beyond the outer sides of said'upstanding pieces, in combination with a third pin passing transversely through and projecting beyondthe sides of one upstanding piece and a short pin in alignment with said third pin, passing transversely through the other upstanding piece and projecting from its outer sideonly.

2. A hearing block comprising a base, two upstanding pieces disposed longitudinally of said base, and two pins passing transversely through and projecting beyond the outer sides of said upstanding pieces at equal dis tances from said base, in combination with a third pin parallel to and between said two pins passing transversely through and projecting beyond the sides of one upstanding piece but not being in contact with the other upstanding piece, and a short pin in alignment with said third pin, passing transversely through the other upstanding piece and projecting from its outer side only, the centre line of said third and short pins being farther from said base than the centre lines of said two pins, but the lower surfaces of said third and short pins being nearer the base than the upper surfaces of said two pins,

substantially as described.

In testimony whereof I have signed my 00 name to this specification.

- ROBERT HENRY COLLEN.

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