US31385A - Piastorobte-agtiost - Google Patents

Description

UNITED STATES IRI/'ING I. HARVVOOD, OF BOSTON, MSSAOHUSET'IF.

PIANOFORTE-ACTION.

:Specification ofLetters Patent No. 31,385, dated Febrnaly l2, 1861.

To all whom it may concern:

Be it known that I, Invixe I. HxnwooD, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Pianoforte-Actions, and that the following description, taken in connection with the accompanying drawings hereinafter referred to, forms a full and exact specification of the same, wherein I have set forth the nature and principles of my said improvements by which my invention may be distinguished from all others of a similar class7 together with such parts as I claim and desire to have secured to me by Letters Patent.

The figures of the accompanying plate of drawings represent my improvements.

Figure l is a side elevation of my improved pianoforte action. Fig. 2 is a central longitudinal vertical section of the same.

In pianofortes, the action as it is termed7 or the mechanical devices through which the touch given by the musician is transmitted to the string forms one of the most essential features of the instrument. rl`he requisites heretofore sought to be combined in a pianoforte action are, first simplicity or the most direct mode of communication between the key and the string'. Second, delicacy of touch or facility7 in repeating a lnote combined with power.

In the most simple forms of actionsi7 power can be obtained but not su'l'licient quickness of movement to render quick repetitions of one or more notes an easy operation7 the tly7 of the jack cannot be in readiness or return into position to lift the shoulder of the hammer until the blow or pressure upon the key-lever has been relieved. In these simple kinds of actions and in most others, it has been common to load the key-lever at or near one end so as to hasten the return of the fly of the jack to its bearing under the shoulder. by which the hammer is to be lifted. But it is manifest that extreme sensitiveness in an action cannot be accomplished by such means, as the force of the blow given by the operator at one end of the key is partially expended in lifting the weight inserted at the other end of the same, and therefore rapid repetitions of one or more notes can not be given, as the key-lever must drop or be relieved sulliciently to allow the jack to come back to its bearing under the hammer.

Although many attempts have been made to construct an action in which extreme sensitiveness of touch or quickness of movement should be combined with power` yet they have only been partially successful as they have necessarily been so complicated as to be practicall ,v inoperative, both on account of their great expense and their liability of frequent dis-organization and the di'lliculty experienced in making the necessary repairs and because some one advantage aimed at has usually been acquired at the expense of one or more equally essential requisites.

The fundamental principles upon which thepresent invention depends consists in preventing the total escape ofthe jack from the shoulder of the hammer which it to lift-or in regulating at pleasure the degree or amount to which the escapement shall occur.l the etlect being to cause the weight of the hammer always to rest upon the jack and conserpiently upon the key-lever. whereby the hammer of course always in i'eadiness for a blow in whatever position the key-lever may be or to whatever extent it may be depressed by the operator. By thus keeping the hammer always in readiness to be impelled against the string it will be evident that quickness of motion the desirability of which in repeating notes. trilling, ttc., well known by pianists can readily be obtained. I effect this result by keeping the hammer always in readiness for a blow or the jack always in position to produce it, which l am well aware has heretofore been done. but has proved piautically unsuccessful by an entirely novel and very simple arrangement of devices the same consisting of a spring-lever placed in any convenient hncality which will insure its resting upon the top of the jack and so operating in connection with the spring of the jack as to push it at and after each blow instantly back to the bearing` or shoulder by which it (the jack) lifts the hammer and forces it against the string'.

a o in the drawings represent the keylever turning upon a center pin or pivot o, the finger end c of which, moves upon a suitable guide pin d of the key-frame c. At or near the rear end of the key-lever is attached a jack f? the fly g of which turns upon a center or pivot h. Upon the upper end of the fly g rests a right-angular butt 2' of the hammer stem and hammer 7c, the butt turning upon a pivot Z of the flange m, which flange m is attached to the flange rail a ofthe key-frame. 0 is the hammer rail upon which the stem of the hammer 7c rests on its return from a blow upon the strings. p is the back-catch.

The finger end of the key-lever being struck by the performer, will transmit the force of the blow to the strings, by the means above described, which operate as follows The finger end of the key-lever being depressed, the rear end will be elevated, and also the jack f and as the butt z' of the hammer head and stem rests upon its fly g, the hammer will be impelled upward and strike the strings. The fly of the jack in rising travels over the rounded edge g of the butt and when the hammer head 7c has struck the strings, in consequence of the force and momentum imparted to it by the performer the fly, will have traveled over or nearly over the said rounded edge Q and moved upon the lower side of the sprintflever 1" fastened to the butt z' in any proper manner. The spring-lever r so long as the l key-lever is depressed, will rest upon the fly g of the jack, in readiness for another blow being imparted to the strings. It will be seen by the above described movements that the total escapement of the fly g from the hammer butt is prevented, for when the butt itself is not resting upon the fly, the spring-lever r which is in fact a part of the butt, is resting upon it. The key-lever being at liberty to assume its original position, the spring-lever r by means of the retracting force of its spring t and acting in conjunction with the spring u of the jack will tend to force the fly of the jack back to its original position under the edge of the butt. The spring-lever r also, it will be seen will prevent the fly from traveling so far off the butt as to allow the butt to drop down upon the side of the ily, for as soon as it leaves the butt z', it is taken by the said lever r,

The spring-lever can be -regulated at pleasure so as to vary the amount of the escape of the jack from the butt, by means of a screw u passing through the butt e'.

o is a screw, having upon one end a suitable bushing w which upon the jack being raised by the key-lever, bears against the cam a: of the fly g and throws or pushes olf gradually the top of the same from the edge of the butt, on to the spring-lever; the screw o has a bearing in the rail y.

It will be seen by the above described arrangement that the object aimed at and secured is to obtain the most direct communication between the key-lever or the operator and the string and this is effected by my improvements by keeping by means of the spring-lever r, the jack always under its bearing or shoulder Q, in readiness for a blow, with the exception of such a very slight interval of time as is required to relieve the hammer from the string after each movement of the key. The power of the action also is increased from the fact that the spring-lever 1' bearing upon the ack renders the communication between the key and hammer more rigid than is possible in ordinary actions. There are many other advantages gained and difficulties avoided by my improvements and arising from the fact that the weight of the hammer is always resting upon the key such as the impossibility of blocking, the sticking or binding of the key-lever, the absence of friction, noise &c. which will be readily Vcomprehended by pianoforte manufacturers and need not be herein more particularly alluded to.

Having thus described my improvements what I claim as my invention and desire to have secured to me by Letters Patent is- A yielding spring-lever resting upon the jack and so operating therewithas to keep the jack at each blow of the hammer in proper position to lift the hammer-butt, whereby the hammer is always kept in readiness to strike the string whatever may be the position of the key-lever.

IRVING I. HARVVOOD.

fitnesses JosEPI-r GAvETT, A. W. BROWN.

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