US1592778A - Leveling device for piano keys - Google Patents

Description

July 13 ,192e. 1,592,778

I... D. PERRY LEVELING DEVI'CE FOR PIANO KEYS Filed June 5, 1924 Patented July 13, 1926. I

UNITED STATES 1,592,773 PATENT orr cs.

LYCUS I). PERRY, OF NEW ROCHELLE, NEW YORK, ASSIGNOR T0 LUDW'IG & COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

LEVELING- DEVICE PIANO KEYS.

This invention relates to leveling devices for piano keys and more particularly to a device especially adapted for use on the keys of grand pianos.

An important objectof the invention is to permitthe leveling of the keys after the installation of the keys in the piano.

A further object of the invention is to pro vide a threaded screw having its lower end arranged adjacent the usual key pin and adapted to be substituted for the latter the fulcrum means of the key, the threaded member being adapted for vertical adjustment to effect the leveling of the key.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the drawings I have shown several embodiments of the invention. In this showa f Figure 1 is a side elevation of a key embodying the invention, and associated elements, parts being shown in section,

Figure 2 1s a section on l1ne 22 of Figure 1, and,

Figure 3 is a transverse sectional View through the key showing a modified form of leveling screw.

Referring to the drawings the numeral designates the usual key frame having a balance rail 11 mounted thereon. The key frame is provided at its rear end with the usual cushion 12 adapted to support the rear end of the key in inoperative position. The usual key 13 is mounted above the balance rail as shown and is provided with a capstan 14 for connection with the operating mechanism of the piano (not shown).

The key 13 is provided substantially centrally thereof with a guide slot 15 adapted to receive a key pin 16 the lower end of which is secured in the usual manner to the balance rail 11. The slot 15 is substantially equal in width to the thickness of the key pin and the latter serves to prevent side motion of the key in operation in the usual manner. The lower end of the slot 15 is restricted as at 17 to snugly lit the key pin 161 The key 13 is provided either forwardly or rearwardly of the slot 15 and in proximity thereto with a substantially vertical threaded opening 18 to receive a threaded re ulating screw 19. The screw 19 is provided with a preferably integral knob or head 20 at its lower end. having a rein-Titled.

lower face having a rounded lower face adapted to be supported upon a cushion 21 glued or otherwise secured on the upper face of the balance rail as shown. The regulating screw may be provided with a flattened upper end 22 for engagement with a suitable tool for rotating the screw to secure proper adjustment.

In Figure 3 of the drawings I have shown a slightly modified form of regulating screw 23. In this form of the device I prefer to use relatively thin threaded wire which may be driven through a previously drilled opening 24% in the key 13. The lower end of the screw is provided with a head 25 similar in construction to the head 20 except that it is formed as a separate piece threaded on the screw 28. In this formof device I also preferably employ the cushion 21 previously described.

The operation of the device is as follows:

The lower face of the head 20 is adapted to contact with the cushion 21 to serve as a pivot point or fulcrum for the key when the forward end of the latter is depressed, the pin 16 serving as a guide to prevent side movement of the key. lVhile the restricted portion 17 of the slot 15 snugly receives the pin 16 the fit between these elements should be sufliciently loose to allow free movemeitzt when the key is depressed. I have found that by placing the screw 18 in close proximity to the pin 16, the relative movement between these members is so slight as to cause no binding action, the action of the key being perfectly free. The operation of the form of the device shown in Figure 3 is identical with that previously described.

When installing the keys in pianos, par ticularly in grand pianos, it has been found practically impossible to provide accurate leveling of the outer ends of the keys regardless of the accuracy of workmanship in manufacturing the individual parts. It is the usual practice to effect the leveling of the keys by a tedious method which requires successive removal and replacing of the keys until the proper leveling is obtained. In the present invention, the keys all may be installed in the piano and leveling of the keys may be readily effected without their removal by turning the screws 18 or 28, depending upon the form of the device employed. The friction between the regulating screw and the threaded opening llil in which it is received is sutiicientto .[irmly maintain the screw in any desired adjuster position. It will be obvious that any suitable form of tool may be employed for turning the screws and they readily may be adjusted in a short space oi time without removing them from the piano. The rounded heads employed on the forms oi regulating screws described provide a smooth contact with the cushion 21 and any slight rearward movement oi the heads when the key is depressed, due to the snug fitting oi the pin 16 within the restricted opening li', will be taken up by the rearward sliding of the heads upon the cushions. This relative movement, however, is so s'ght as to be entirely negligible and does not atlect the tree action or" the keys.

It is to be understood that the for r; of my invention herewith shown and described are to be taken as preferred e nip s oi tne same and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the sub joined claims.

Having described my invention, I claim:

1. In a piano action, a balance railv a key mounted above the rail and provided with a guide slot having .a restricted lower end, a key pin carried by the rail and projecting upwardly throughflsaid slot, said pin being snugly received in the restricted portion of said slot, and a vertically adjustable fulcrum pin carried by said key adjacent said key pin and slidably resting upon said balance rail.

2. A device constructed in accordance with claim 1 wherein said fulcrum pin provided at its lower end with an enlarged head having a rounded lower face contacting with said rail.

3. In a piano action, a balance rail, a lzey mounted above the rail and provided with a guide slot having a restricted lower end, a key pin carried by the rail and projecting upwardly through said slot, said pin being snugly received in the restricted portion oi said slot, and a vertical fulcrum pin threaded through said hey adjacent said hey pin and slidably resting upon said balance rail.

l. In a piano action, a balance rail, a key mounted above the rail and provided with a guide slot having a restricted lower end, a key pin carried by the rail and projecting upwardly through said slot, said pin being snugly receivd in the restricted portion of said slot, a vertical fulcrum pin threaded through sait key adjacent said hey pin, an enlarged head carried by said fulcrum pin at its lower end and provided with a rounded lower face, and a cushion arranged on said rail, the rounded lower face of said head being adapted to slidably rest upon said cushion.

In testimony whereof I ai'iix my signature.

LYoUs D. PERRY.

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