US750035A - Pianoforte - Google Patents

Description

No. 750,035. PATENTED JAN. 19, 1904.

F. MGNAMARA.

PIANOFORTE.

.APPLXOATION FILED 0GT.14. 1903.

L N0 MODEL.

2 SHEETS-SHEET 1.

yNo. 750,035. PATENTED JAN.19, 1904.

F. MGNAMARA.

PIANOFORTE.

APPLIATION FILED 0GT.14. 1903.

N0 MBEL.` d 2 SHEETS-SHEET 2.

#or'g a EN* QW@ UNITED STATES Patented January 19, 1904.

PATENT OFFICE.

PIANOFORTE.

SPECIFICATION forming part of Letters Patent No. 750,035, dated January 19, 1904.

Application filed October 14, 1903. Serial No. 176,945.

T0 all 1071/0777/ t ntf/,y concern:

Be it known that I, FRANK MCNAMARA, of Clinton, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Pianofortes, of which the following' is a specification.

This invention relates to the means for supporting the string's of a pianoforte; and it has for its object, first, to equalize the tension of the strings uniformly throughout their entire leng'th, so that when the tension is increased by the turning of the tuning-posts the increase will be uniformly distributed throughout the entire leng'th of each string.

The invention also has for its object to provide means whereby a considerable part of the pressure of the strings on the bridge, which is interposed between the strings and the sounding-board and is in contact with the latter, will be supported mainly by the rigid stringplate of the instrument instead of by the resonant sounding-board, thereby reducing' to the minimum the interference with the vibrations of the sounding-board due to the pressure of the sound-conducting bridge upon it.

The invention consists in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification, Figure 1 represents a front elevation of the string-plate and sounding-board of a piano embodying my invention. Fig'. 2 represents a section 0n line 2 2 of Fig. 1. Fig. 3 represents a section on line 3 3 of Fig. 1. Fig. I represents asection on line 44 of Fig. 1. Fig. represents an enlargement of a portion of Fig. 1. Figs. 6 and 7 are perspective fragmentary views showing in perspective parts which are shown in section in Fig. 4.

The same reference characters indicate the same parts in all the figures.

In the drawings, a represents the soundingboard of a piano.

b b represent the usual strings.

c c represent the tuning-posts, which are frictionally engaged, as usual, with abeam or bar d, aflixed to the frame of the piano, and e represents the rigid string-plate, which is (No model.)

usually made of cast-iron and is located beside the sounding-board.

The g'eneral construction and arrangement of the above-mentioned parts is or may be the ordinary construction and arrangement, excepting as hereinafter specified.

Each string is attached at one end to a pin f, rigidly aflixed to the string-plate 1, as usual, the ends of the strings attached to the pinsf being hereinafter referred as the i fixed ends, these being' opposite the ends which are adjustably connected with the tuning-posts c in the usual manner.

g represents the bridge, which supports the strings at points adjacent to their fixed ends and is in contact with the sounding-board u, said Abridge being usually made of resonant material, such as wood, and serving to conduct vibrations from the strings to the soundingboard.

In carrying out my invention I provide the string-plate c with an extension d, which is formed and arranged to support a iiange y, formed on the bridge y, said iiange being' bolted or otherwise secured to the extension c', so that the bridge, while in contact with the sounding-board, is supported mainly by the string-plate Hence the pressure exerted by the strings upon the bridge g does not interfere with the resonance of the soundingboard to such an extent as it would if the bridge were not supported, as described, by the string-plate.

The string-plate is provided with suitable means for supporting the strings at points adjacent to the tuning-posts c. In this enibodi ment of my invention the said means comprise a series of antifriction-rollers it, having shafts or trunnions 7J, which are preferably cast upon the string-plate. The bridge g/ is also preferably provided with a series of antifriction-rollers 71 which are partially received in cavities j, formed in the bridge g, said cavities having sockets y" attheir ends, (see Fig'. 7,) which sockets support the trunnions 7L of the rollers 72.. For convenience the rolled upon a sing'le shaft 71..

rattling of the rollers la, against each other and against their supports, washers h2, of felt or other material, are interposed on the shafts f.

It will be seen that each string is supported between its fixed and adjustable ends on two freely-rotatable antifrictional rollers. Hence when the tension of a string' is varied by the adjustment of a tuning-post the variation will extend uniformly throughout the entire length of the string. This uniform distribution of the tension of the strings is a very important factor in keeping the strings in tune, as l have found by practical experience.

I am aware that it has been proposed to support the strings at points adjacent tothe tuning-posts by antifriction-rollers; but I am not aware that piano-strings have ever' been supported at two points by antifrietion-rollers, one point being adjacent to the tuning-post and the other adjacent to the fixed end of the string, so that the tension is made uniform throughout the entire length of the string.

I claim-v l. 1n a piano, the combination of the soundf strings at points near the tuning-posts, and the 1 string-supporting bridge aflixed to the portion of the string-plate which supports the fixed ends of the strings, said bridge being in contact with the sounding-board but supported by the string-plate.

Q. ln a piano, the combination of the sou nding-board, the strings, the tuning-posts, the string-plate having' a series of string-supporting antifriction-rollers located near the tuningeposts, and another series of antifrietion rollers supporting the strings near the fixed ends of the latter.

3. 1n a piano, the combination of the sounding-board, the strings, the tuning-posts, the string-plate having a series of string-supporting antifrictien-rollers located near the tuning-posts, and a bridge affixed to the frame near the fixed ends of the strings and in contact with the sounding-board, said bridge having another series of' string-supporting antifriction-rollers.

ln testimony whereof l have aflixed my signature in presence of two witnesses.

F {ANK MCNANIA RA. lVitnesses:

VAL'rifnz l). AnlcLL, E. BA'reIIuLpnn.

Images