US2469738A - Tuning device for pianofortes - Google Patents

Description

INVENTOR ATT &

J/m fle/szner 40. 144

OR Y

IIII/I/ IIIIIIIIIII III/III!!! IIIIII 4 I III May 10, 1949.

a M 3 .Jw w 2% 1 Patented May 10, 1949 U ED STATES PATENT OFFICE l-Claim. 1

This invention relates to tuning devices for pianofortes, and has for its object to provide a tuning device by the use of which strings are subjected only to-a-straight line pull while-tuning, and remain substantially permanently tuned under varying atmospheric conditions.

In the present devices .for tuning the strings are required to be bent around a tuning min, which bending subjects a string not alone to the tension forces but also to flexing forces, which adjust-themselves after the tuning has been completed, and thereby change the tuning eifect. Also, frequently the removal of :a tuning hammer changes the tension. Also, the present tuning pin platesutilizing wood, are subjected'to different expansionfactorsthan-the steelstrings. Also, all possibility of various defects caused by loose tuning pins now placed in a wooden :pin block, such as (a) Yielding to the increased tension caused by hard strokes of the felt hammer,

Yielding "to change in'weather conditions, Yielding to long and strenuous playing,

by sudden and hard strokes some unisons (the three strings :making upa note) to become out .ofconcertpitch by one or more vibrations. These objections are overcome.

The invention consists of a *tensioning device disposed between a wall of a piano cast frame andthe end of a'string, inwhich thepulling force Complete elimination of friction between the of the tensioning device is aligned with the length of the string, for bringing the tension of the string to the proper vibration number.

More particularly, in the embodiment, the ten- ,sioning device consists of .a turnbucklevhaving one of its rods connected with the end of a string and the other rod connected with a wall of the cast frame, whereby upon the turning of the sleeveof the turnbuckle, the string is placedunder the tension desired, the string being subjected .only totension and not to torsionior twisting-during the tuning of the string.

The invention will be further described, an

embodiment shown in the drawing, and the in- ,1

vention'will be finally pointed out in theclaim.

In the accompanying drawings, Fig. 1 is a diagrammatic plan view of a grand piano, embodying my improvement;

Fig. 2 is an enlarged sectional view taken on Cl. 84-q205) o'fjFig. 2, .and

?Fig. 4 is a longitudinal section of a sleeve :part of the turnbuckle :and having interior screw threads.

Siniilar characters of referenceindicate corresponding parts throughout the various views.

Referring to the drawings, the usual grand piano is shown diagrammatically in plan in Fig. L'With the piano case 10, cover II, cast frame iibridge i3, and hitch pins 1 4.

The improvement consists in providing adjusta'ble means 45 to the known front wall [6 of the casing 10, which means [5 engage looped ends 1*! .of the strings H3. These strings 18 have their other ends secured to the hitch pins I4, as known, and pass over the knownbridge i 3, and under theagraffeas shown in Fig. 2.

'Thepreferredform of adjusting means l5 comprise turnbuckles'ZU consisting of a sleeve 2| hav 'ing interior screwthreads 22 and 23 as shown in Fig. 4., each end engaged by screwthreaded rods .Zfiand 211,. The threadsare very .fine to provide the most accurate of adjustments. Thestrings [8 are looped .by bending back the end vof the string and winding the end on the string on itselfas at 2 4, and the loops 1? are engaged by a :hook 25, on one-of .the before mentioned rods 2.6, which is exteriorly screwthreaded to engage the interior screwthreads 23 0f thesleeve 21. The

other :screwthreaded end 22 of the sleeve 21 is engaged by the screwthreadedrod '21, which'has a :head'.-28, of square or other shape.

The :known front wall "5 of the .piano frame is provided, in accordance with the invention, with tbores 2-9 for :the passage of the rod 21, and the front surface of :the front wall is provided with grooves 38 and recesses 3! for the heads 2'8 of the rods 27. The grooves 30 form a convenient rorin o'f providing the recesses '3 l, since only short -cu'touts need be made in order to provide the rewall 33. The lower part is curved with the shortest practical radius of curvature.

After the rods 28 have been connected with the strings l8, and after the rods 21 have been inserted through the bores 29, with the bolt heads 28 locked against turning in the recesses 3|, the sleeve 21, which is preferably hexagonal, is finally adjusted to the pitch desired, preferably with the aid of a three edge tuning device or hammer.

The adjustment then remains substantially permanent.

Among the advantages of the improvement is the alignment of the connecting means with the strings in substantially a straight line. The tension on the strings is direct until the desired vibration number (440) is obtained for each string. l'he vibrating parts of the strings from the agraffe to the pins is longer than when tuning pins are used, which tuning pins are on the frame inward of the front wall of the frame, becaus with the improvement the agraffe may be placed nearer to the front wall, and because with the improvement the removal of the pin block and its iron plate cover opens up this section of the piano to a free sound. The factory tuning seasoning can be completed in about a few weeks. At present time, a, piano requires rough tuning, then re-tuning, and after such repeated tunings, a final tuning before the piano can be released from a factory. Thus seasoning takes about a year. Thereby, the storage expense, as well as the capital investment expense, is reduced. The tuning pin block and iron plate which is about 8 inches in depth are eliminated. By attaching the strings to the front wall of the frame, about 2 to 3 inches are gained for the length of the strings which is particularly important for the high register treble strings, the resonant vibrations of which are increased, and the present rather tiny or dull sounds obviated. The gain in length of the strings give greater resonance (vibrato), and give greater clarity in the upper registers particularly. This is specially important for smaller grands and uprights and will also be to the advantage of the concert grands. There is a better equalizing of the high, middle and low registers. The improvement prevents the change in vibrations of the entire instrument after having been played in concert, is now frequently the case to the extent of one or more vibrations on one or more strings. As the improvement is made of metal, it acts substantially the same way as th strings under the prevailing atmospheric conditions, Whereas the present use or wood used in connection with the tuning pins has different expansion characteristics than metal. The stretching of the steel strings is by pulling only, and no part of the string is bent as by surrounding the tuning pin. Once the tuning of a string has been completed, it is not changed, as is the case when a tuning hammer is removed which removal frequently changes the pitch, and puts the three strings out of harmony.

It will be particularly noted that the ends of the strings 8 at the connection of their hooks 20. with the hooks 25, are freely disposed or float ing in air, instead of being held down to a sur-- face.

Each of the strings is under a pull or tension of one hundred and fifty seven pounds, and in consequence, the invention contemplates the use of such tension resisting turnbuckles. Furthermore, these turnbuckles are finely adjustable. Each turnbuckle is separate from the other. Each turnbuckle has a separate anchoring place. Each anchoring base of each turnbuckle is at right angles to the axis of the turnbuckle. The anchoring bases of th turnbuckles are so disposed in vertical staggered arrangement along the end wall, so as to enable every string of a piano to be separately controlled and tuned, and the relationship of the turnbuckles to the wall 33 is such that the superposed angularly disposed strings, each pass under the wall 33, one next to the other. The adjustment or tuning of such superposed strings is carried out by th use of the turnbuckles in line with the angularly disposed strings. In each case the axis of the turnbuckle is in alignment with the strings, and this is achieved by providing the bore 29 in alignment with the string. By vertically disposing the turnbuckles so that they take up little space laterally, the number of turnbuckles corresponding to the number of strings may be accommodated.

I have described several forms of my invention, but obviously various changes may be made in the details disclosed without departing from the spirit of the invention as set out in the following claim.

I claim:

In a tuning device for pianofortes having a piano frame with a hitch pin for on end of a string, said string having a loop at its other end, a bridge for the string, an agraffe having a curved part on which the string passes, and an end wall transverse to the frame and spaced from the agra-fie and having bores and square recesses at the ends of the bores, the combination of a plurality of turnbuckles disposed between the transverse wall and the agraffe, and each having one end secured to a rod passing through a bore of the wall, and having a square head engaging a square recess in the end wall and each turnbuckle having a hook to engage a loop, each hook of each turnbuckle being at right angles to the axis of the turnbuckle, and the connecting seat of each hook and loop being aligned with the axis of the turnbuckle, said hook and loop connection subjecting the string to tension without twisting or torsion of the string, the agraife being spaced near the loop of the string held by the turnbuckle, and the space between the wall and agraife being in free communication with the space below the wall and agraffe, whereby substantially the full length of the string between the agraife and the bridg may be utilized for resonant vibrations, and the tensioning of the string is free from twisting or torsion of the string.

JOHN MEISZNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 119,760 Hastings Oct. 10, 1871 267,150 Chard et al Nov. 7, 1882 319,188 Brinsmead June 2, 1885 FOREIGN PATENTS Number Country Date 47,735 Germany Dec. 4, 1888

Images