US904117A - Piano-action. - Google Patents

Description

A. B. .GRDSS.

PIANO ACTION. APPLICATION FILED JUNE 7, 1908. RENEWED OUT 10, 1908.

904, 1 1 '7. Patented Ndv. 17, 1908.

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A. B. GROSS.

PIANO ACTION.

APPLICATION FILED JUNE 7, 190a. RENEWED OUT 10, 190R.

904,1 1 7. Patented Nov. 17, 1908.

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UNITED srarns PATENT OFFICE.

ALONZO B. CROSS, OF CONCORD, NORTH CAROLINA, ASSIGNOR OF ONE-HALF TO BASCOM L.

UMBERGER,

OF CONCORD, NORTH CAROLINA.

PIANO-ACTION,-

To all whom it may concern:

Be it known that I, ALoNzo B. Cnoss, a citizen of the United States, residing at Concord, in the county of Oabarrus and State of North Carolina, have invented a new and useful Piano-Action, of which the following is a specification.

This invention relates to and has for its principal object to simplify, improve and cheapen the construction of upright piano actions, most of the parts employed in modern actions being wholly eliminated.

A further object of the invention is to provide a novel construction of jack in which the jack is inclined rearward from its point of connection with the rocker, so that the principal weight will be to the rear of the piano actions,

Specification of Letters Patent.

pivot. point, the vertical plane of the center of gravity of. the jack being constantly to the rear of the vertical plane of the pivot, so that the jack is free to return to its normal position by gravity and without the aid of a spring.

A still further object of the invention is to improve the construction and arrangement of the hammer butt, the back stop, and jack, with a view of insuring perfect action of the hammer, and insuringthe return of the parts to proper relative position when pressure on the key is relieved.

A still further object of the invention is to improve the arrangement and mounting of the damper and hammer springs, and to eliminate the usual hammer.

lVith these and other objects in view, as will more fully hereinafter appear, the invention consists in certain novel features of construction and arrangement of parts, hereinafter fully described, illustrated in the ac companying drawings, and particularly pointed out in the appended claim, it being understood, that various changes in the form, proportions, size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings :Figure 1 is a sectional elevation of a piano action constructed in accordance with the invention. Fig. 2 is a similar view, showing the key depressed and the positions of the parts immediately following a stroke of the hammer.

Similar numerals of reference are em Patented Nov. 17, 1908.

Renewed October 10, 1908. Serial No. 457,172.

ployed to indicate corresponding parts throughout the several figures of the drawings.

The entire action is mounted on a base board 10 and standards 11. On top of the base board are located the rails 13, 14 and 15 for the support of the keys 16. The standards 11, or any other suitable supports within the casing of the instrument, serve to support the center rail 19 and a hammer rest rail 20.

To the hammer flange 21 is pivoted the butt 22 of the hammer shank 23, and from the butt extends the shank 2a of the back stop or check 25. The hammer butt is provided with a depending toe or trip 26, which, during the operative movement of the hammer, comes against the upper end of the jack 2?, and forces the same outward from the position shown in Fig. l to the position shown in Fig. 2, and that face of the butt which the jack engages is provided with a lining or covering 28, formed of felt or other suitable material. The upper end of the jack is provided with a small projection 29 which is approximately wedge like in form, and on its forward faceis a small cushioning pad 30 which is arranged to engage against a similar pad 31 carried by the back check, the two pads being moved into engagement with each other at each stroke of the hammer.

Near the rear end of each key is secured a rocker 32, to which the lower end of the jack 27 is pivoted, and the lower end of the jack has a forwardly extending arm 33, the lower face of which may engage with a lining or pad 34 carried by the rocker, while the upper face of this arm is arranged to engage against an adjustable stop button carried by a cross rail 36. These buttons serve to engage the arm 33, as the key is swung upward, and thus assist the trip 26 in moving the jack from the position shown in Fig. l to that shown in Fig. 2, and the upper end of the jack will remain in the position shown in Fig. 2 in order to form a stop against which the hammer strikes when it rebounds. The ack is locked in the position shown in Fig. 2 so long as the front end of the key is depressed, but as soon as pressure on the key is relieved and the arm 33 moves downward from the button, the rear end of the jack will move downward and rearwardly by gravity, allowing the hammer to move back against the hammer rest rail, and the parts being thus returned. to proper position. It will be noted that the jack inclines upward and rearward from the point where it is pivotally connected to the rocker and that the principal weight of the jack is to the rear ofthis pivot. During all positions of the jack the vertical plane of its center of gravity is to the rear of the vertical plane of the pivot, so that the jack is free to move to its normal position by gravity and without the necessity of relying on a spring. This movement is assisted by the hammer spring 38, which is secured to the damper flange preferably by the same means employed to hold the damper spring 39 in place, thus dispensing with the usual hammer spring rail.

To the rear base rail 15 is secured a flange 40 to which is pivoted a bell crank lever 41, having an approximately horizontal arm that engages a pad or lining 42 carried by the rear portion of the key 16. The approximately vertical arm of the bell crank lever engages against the cushioned lower end of a damper lever 43, which is pivoted to the damper flange 44:, and carries a damper 45 of any ordinary construction.

lVith the parts in the position of rest illustrated in Fig. 1, the damper is held against the string by the spring 39, and the spring acts, also, bell crank lever ll to hold the rear end of the key depressed, so that it will not be necessary to employ the usual leaden Weights at the rear ends of the keys. hen a key is depressed the movement is transmitted direct through the jack 27 to the hammer butt. The trip 26 throws the jack to the position where it is freed therefrom, which occurs just before the hammer strikes the string, and therefore leaves the hammer free to rebound so that it will not block the string. At this point the button 35 engages the arm 33 and holds it against the rocker 32 until the key is released. While the button is holding down the arm in this manner it is also holding the upper end of the jack against the back check 25 thereby preventing the return of the hammer to the string. When the key is released it is evident that the upper end of the ack must return to its position under through the damper lever and the the hammer butt and during this movement t-hejack comes into contact with the trip 26 and. assists the hammer spring 38 in forcing the hammer back to the rail 20. Better repetition is thus insured. The particular shape and position of the ack permits the spring usually employed to be dispensed with. From the foregoing it will be seen that both the trip and the button have distinctive acts to perform. The trip in the first instance lightens the work of the button and subsequently insures the return of the hammer to its initial position against the rail 20.

I claim In a piano action, a key, a rocker secured thereto, a jack pivoted to the rocker, an arm extending forward from the base of the jack, the jack being inclined upward and rearward, and the vertical plane of its center of gravity being constantly to the rear of the vertical plane of the pivot, an adjustable button with which the jack arm engages during the upward movement of the rocker, a projection extending from the forward face of the upper end of the jack and having a cushioning pad, a rail, hammer and damper flanges carried thereby, a hammer bntt pivoted to the hammer flange and provided with a pendent trip arranged to throw off the jack during the hammer stroke, a back check carried by the hammer butt and normally spaced from the cushioned projection of the jack, the upper end of the jack and its projection being arranged to engage between the butt and back check at the end of the hammer stroke, a damper pivoted to the damper flange, a spring carried by the rail and arranged to engage both the hammer butt and the damper, a lower flange disposed to the rear of the key, and a bell crank lever pivoted to said lower flange and having one arm engaging the damper and the other the key.

In testimony that I claim the foregoing as my own, I have hereto aflixed my signature in the presence of two witnesses.

ALONZO B. CROSS.

Vitnesses J AS. P. COOK, CHAS. E. BOGER.

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