US2751804A - Self-adjusting piano action damper mechanism - Google Patents

Description

June 26, 1956 J. J. COMPARETTI 2,751,304

SELF-ADJUSTING PIANO ACTION DAMPER MECHANISM Filed Jan. 5, 1955 58 52 INVENTOR.

I Joseph J (bmparefibi.

A TTOENE Y United States Patent SELF-ADJUSTING PIANO ACTION DAMPER MECHANISM Joseph J. Comparetti, Long Island City, N. Y. Application January 3, 1955, Serial No. 479,327

3 Claims. (Cl. 84-255) This invention relates to improvements in damper mechanisms for piano actions, and particularly relates to improvements in the adjustability of such mechanism to make them self-adjusting.

Piano action dampers of the type with which this invention is concerned, have a damper head which is adapted to contact the piano string while the tail portion of the damper mechanism is in contact with the damper actuating rod. The damper mechanism generally comprises a lever pivoted at its center to the action rail and the damper head is provided at the top end of the lever while the tail is at the bottom. In order to have the dampers in perfect adjustment, it is necessary that all the dampers move toward and away from their strings simultaneously when the actuating rod is moved. In order to obtain the fine adjustments of each damper necessary for such precise simultaneous movement, it was, heretofore, necessary to use a special tool to bend the damper wire, which forms the upper portion of the lever, just the right amount. This required a relatively great amount of skill and experience as well as an inherently deft touch.

It is one object of the present invention to provide a piano action damper which may be easily adjusted relative to the string without any great amount of skill or experience on the part of the person making the adjustment.

Another object of the present invention is to provide a piano action damper which is capable of substantial universal adjustment.

Another object of the present invention is to provide a piano action damper which consists of relatively few parts, although it is completely adjustable.

Other objects of the present invention are to provide an improved piano action damper, of the character described, that is easily and economically produced, which is sturdy in construction, and which is highly eflicient in operation.

With the above and related objects in view, this invention consists in the details of construction and combination of parts, as will be more fully understood from the following description, when read in conjunction with the accompanying drawing in which:

Fig. 1 is a side elevational view of a damper embodying the present invention.

Fig. 2 is a rear elevational view of the damper of Fig. 1.

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 1.

Fig. 4 is a fragmentary side elevational view of one of the pivoted joints shown in Fig. 1, this view being taken on line 4-4 of Fig. 2 and showing the side of the joint opposite to that shown in Fig. 1.

Fig. 4a is a view similar to Fig. 4 but showing the damper in a different position of adjustment.

Referring now is greater detail to the drawing wherein similar reference characters refer to similar parts, there is shown a lever pivoted at 12 to a bracket 14 which extends from the action rail 16 and is attached thereto by screw 18. The tail portion 20 of the lever is provided with a pad 22, of felt or the like, in the conventional manner for contact with the damper rod 23.

At the top portion of the lever 10 is provided a groove 24 and in this groove there is fitted a tongue 26 integral with a yoke 28. The yoke 28 is also provided with a housing 30 having a groove 32 therein. This groove 32 receives the wider flange 34 formed on top of the lever 10, the flange on the other side of groove 24 being indicated at 36. The two flanges 34 and 36 are formed by the groove 24.

The resultant structure, in effect, comprises a double tongue-and-groove arrangement between the top of the lever and the yoke 28 whereby each part has one tongue fitting into a groove on the other. A pivot pin 38 extends through both tongue-and-groove construction whereby the yoke is pivotally connected to the top portion of the lever 10. A set-screw 40 tapered and threaded to a sharp point 41 extends through the top of the housing 30 and, when screwed down suificiently, its point 41 screws into the top of flange 34 to lock the yoke in any position of pivotal adjustment, the maximum possible forward adjustment being shown in dash outline in Fig. l.

A spring 42 is connected at one end to a rod 42 on the bracket 14 and, at its other end, it fits into a groove 44 at the rear top portion of the yoke. The spring 42 thereby acts to bias the yoke toward the left, as viewed in Fig. 1, and toward the right as viewed in Figs. 4 and 4a. A pad 46 of felt, sponge rubber, or the like, is provided in the groove 44 to cushion the top end of the spring. A stop 48 is provided on the front top edge of the flange 36, as best seen in Figs. 4 and 4a, and adapted to contact the stop for the purpose of preventing pivotal movement of the yoke beyond a predetermined position, is an inclined stop edge 50 which is formed on one side of the yoke.

Mounted in the yoke 28 and extending upwardly therefrom is a wire or rod 52. Positioned at the top of rod 52 is a pivot head 54. This pivot head is slidably adjustable longitudinally of the rod 52 but is adapted to be fixed in adjusted position by set-screw 56. A triangular fiange or tongue 58 extends outwardly from the front face of the head 54 and fits within the central groove 60 of a yoke 62. A pivot pin 64 pivotally connects the tongue 58 to the yoke 62. Connected to the front face of the yoke 62 is a block 66 to which is attached a pad 68 of felt or the like, this pad being adapted to contact the string 70. The tongue-and-groove connection between tongue 58 and yoke 62 is made sulficiently close to effect a frictional binding action between the tongue-and-groove. In this manner, when the yoke 62 has been pivotally adjusted, it will be maintained in its position of adjustment merely by friction. On the other hand, the fit is not so close as to interfere with the manual adjustment of the parts.

When it is desired to adjust the damper, the head 54 is adjusted to the correct position on the rod 52. Then the yoke 28 is pivoted until the pad 68 contacts the string 70. The yoke 62 is then pivotally adjusted until the pad 68 lies perfectly flat on the string 70 so that, when it comes off, it comes off evenly on top and bottom. The pad remains in this position of adjustment because of the frictional binding action between the tongue 58 and yoke 62. When this has been accomplished, then it is merely necessary to tighten the set-screw 40 which makes the yoke 28 rigid on the lever. The damper mechanism has now been completely adjusted.

It should be noted that the damper mechanism illustrated here is not only pivotally mounted at the center of the lever as in the conventional types, but is also provided with pivotal adjustments which combine to form a generally universal adjustment means. Furthermore, the spring 42 not only biases the lever, on its pivot 12, toward the string 70 but also acts to bias the yoke 23 on its pivot 38. This dual function of the spring provides a simple, yet highly efficient, control means.

Although this invention has been described in considerable detail, such description is intended as being illustrative rather than limiting, since the invention may be variously embodied, and the scope of the invention is to be determined as claimed] Having thus set forth and disclosed the nature of this invention, what is claimed is:

1. In a piano action damper mechanism having a bracket adapted to be fixed to an action rail and a lever intermediately pivoted to said bracket; a yoke pivotally connected to the top portion of said lever, a spring biasing said yoke, around its pivot, in one direction, a stop on said yoke limiting pivotal movement of said yoke in 20 said one direction, locking means on said yoke adapted to lock said yoke to said lever in any position of pivotal adjustment, an extension member on said yoke, and a pad having a pivotal connection to said extension memher, said pivotal connection between said pad and said extension member being constructed and arranged to be held rigid in any position of pivotal adjustment of said pad.

2. The damper mechanism of claim 1 wherein said yoke has a tongue-and-groove connection with said lever, and wherein said locking means comprises a set-screw extending through a portion of said yoke and adapted to be moved into locking engagement with the top of said lever.

3. The dmaper mechanism of claim 1 wherein said extension member is a rod, and wherein said pad is fixed on a block, said block being pivoted to a head, and said head being slidable on said rod, there being locking means for locking said head on said rod in any position of longitudinal adjustment along the length of said rod, and there being a binding action between said block and said head.

References Cited in the file of this patent UNITED STATES PATENTS 595,458 Nickel Dec. 14, 1897 1,184,181 Holden May 23, 1916 FOREIGN PATENTS 3,221 Germany Feb. 27, 1878

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