US126848A - Improvement in duplex agraffe scales for piano-fortes - Google Patents

Description

e, F. T. sTEl'NwAY.

Improvement in Duplex Agraffe Scales for Piano-Fertes. N0. 126,848. Patentedl\la1y14,187.2.,A

UNInn STATES' PATENT OFFICE.

G. F. THEODOR STEINWAY, 0F NEW YORK, N. Y., ASSIGNOR TO HIMSELF, .elli-BART STEINVAY, AND WILLIAM STEINWAY.

IMPROVEMENT IN EUPLEX AGRAFFE SCALES FOR PIANO-FORTES.

Speciiication forming part of Letters Patent No. 126,943, dated May 14, 187

To all whom it may concern:

Be it known that I, (l. I?. Trinonon S'rnnt WAY, of the city, county, and State of New York, have invented anew and Improved Duplex Agrai'e Scale for Piano-Fortes; and I do hereby declare the following to be a full, clear, and exact description thereof, which will enable those skilled in the art to make and use the saine, reference being had to the aecompanying drawing forming part ot this specification, which drawing represents a plan of a grand piano-forte with my improved scale.

My invention consists in brin ging the vibrations of that portion or' the string which is situated between the agrade and the tuningpin, in proportion to those ot' the main portion of the string, in such a manner that the tone produced by said a gratie section is brought in harmony with that of the main section, and thereby the purity and fullness of the tone of the instrument is materially increased, also,4

in bringing the longitudinal vibrations of that portion ot' the string which is situated between the sounding-board bridge and the hitch-pin in proportion to the vibrations of the main section of the string, so that the sounds due to these longitudinal vibrations are brought in harmony with the tone ot the main section of the string, and the purity and fullness of the tone of the instrument is improved.

In order to enable others to understand my invention, I will here remark that the term scale77 of a piano-torte comprises the position of the strings side by side or above each other, their length and thickness and their tension; and my improvement is applicable to all stringed instruments in which the sounds are produced by the action ol hammers.

If the bass tones of a stringed hammer instrument are sounded -irom octave to octave toward the trcblea great diiierence appears in the effect of the various strings, according to their length, as far as the partial tones of the strings are concerned, which are duc to the spontaneous subdivisions of said strings in halves, quarters, eighths, sikteenths, 85o. rl'he longest duration ofthe vibrations and the highest quality' to subdivide in partial tones is found in the strings between the contra C and the small c. Within these limits each string subdivides itseli` by the blows of the hammer and by the transverse vibrations due to the same in a large number of nodes whereby the so-called harmonic overtones are produced, and whereby the fundamental tone is rendered rich and brilliant. At the same time this portion of the strings, particularly, produces, by the longitudinal vibrations, a number of unharmonic side tones, making a whistling sound, which disturbs the purity of the tone. Both these qualities disappear as the height of the tone increases, so that the limit of producing a pure fundamental tone is found at a4, while it is in most cases desirable to obtain a clear tone from c5,- but the inherent firmness of the thick strings generally employed, and the great tension required on account of thickness prevents the string ot' the above-named o5 to make the proper transverse vibrations due to the fundamental tone, and a division into partial tones is out of thc question. In order to eft'ect or promote the subdivision of the string and to produce the desired partial tones, I combine with that portion of the string which is situated between the tuning-pin a (see drawing) and the main agrafte b a secondary agratt'e, c, which supports the string and is placed at a distance from the main agrae corresponding to one of the above-named subdivisions of the main section d oi' the stringthat is to say, at a distance equal to l, l, 15, or of the length of the main section, or to any combination ot' these fractions. The main agrafte Z), which supports the string only at one point, allows the transverse vibrations to extend to that part of the string between the said agrafte and the tuning-pin, the vibration of this part being in a direction opposite to that of the main section of the string. By inserting the second agrafi'e c at a distance from the main agraffe equal to gf, gg, ,15, 517 or E13 of the length of the main section oi the string, the subdivision of the string into partial vibrations, and the consequent production of harinonic overtones is effected or promoted7 and a clear, strong, and brilliant tone is obtained up to the highest note.

In the drawing I have marked opposite to each tuning-pin the proportion existing between the distance of the two agra'es and the length of the main section of the string.

By allowing the vibration of the strin g to extend beyond the main agraie the durability of the string is materially increased, since by cutting oft` the vibration of the string at this bration of the strings, I avoid by supporting that portion of the string between the sounding-board bridge and the hitch-pin at distances from the outer bridge-pins equal to l, or 51T of the length of the main portion of each string, or kto any combination 0f these fractions. By the sounding-board bridge the continuation of the transverse vibrations must necessarily be interrupted, owing to the width of the bridge supporting the string, whereby these vibrations are ei'ectually stopped; but particularly With strings of'great thickness, as generally used in piano-fortes of recent construction, the longitudinal vibrations ofthe strings .extend to those portions which are situated between the kbridge and the hitchpins; and in order to avoid unharmonic tones due to these longitudinal vibrations I apply between the bridge and the hitch-pin g, under each string, a support, e, at a distance from the outer bridge-pinf, corresponding to T15, 3 1? or of the length of the main section d of the' string, or to any combination of these fractions.

In the drawing I have marked opposite to each hitch-pin the proportion existing between the distance from the support c to the bridgepin and the length of the main section of the string. By these means the unharmonic tones due to the longitudinal vibrations ofthe strings are converted into harmonious tones, whichl being transmitted through. the bridge to the sounding-board reach the ear and strengthenl and enrich the fundamental vtone of the string, instead of disturbing the purity thereof, as heretofore. The supports c and e may be made of metal, ivory, or any other material capable of resisting the pressure of the string.

What I claim as new, and desire to secure by Letters Patent, is

l. rIhe arrangement, in a piano-forte, of a g series of successive strings, in each of which the vibrations of that portion situated between the agraie and tuning-pin are brought in har- Witnesses W. HAUFF, E. F. KASTENHUBER.

C. F. THEODOR STEINVAY.

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