US3651733A

US3651733A - Hammer butt with adjustable hammer shank

Info

Publication number: US3651733A
Application number: US68200A
Authority: US
Inventors: Merton D Corwin; Walter E Dietrich
Original assignee: DH Baldwin Co
Current assignee: BPO ACQUISITION CORP; Baldwin Piano and Organ Co; DH Baldwin Co
Priority date: 1970-08-31
Filing date: 1970-08-31
Publication date: 1972-03-28
Anticipated expiration: 1989-03-28

Abstract

A hammer butt for use in a piano action, said hammer butt preferably being molded from plastic and having an integral socket for receiving the end of a hammer shank which is circular in cross section, the opening in said socket being of a width to engage opposite sides of the hammer shank and of a length greater than the diameter of said hammer shank so that the hammer shank may be tilted relative to the socket so as to bring the hammer shank and the hammer mounted thereon into accurate alignment with the string to be struck by the hammer.

Description

United States Patent Corwin et al.

1 51 Mar. 28, 1972 [54] HAMMER BUTT WITH ADJUSTABLE HAMMER SHANK [72] Inventors: Merton D. Corwin; Walter E. Dietrich, both of Cincinnati, Ohio D. H. Baldwin Company, Cincinnati, Ohio Aug. 31, 1970 [73] Assignee:

[22] Filed:

[21] Appl.No.: 68,200

1,650,095 11/1927 Rydberg FOREIGN PATENTS OR APPLICATIONS 236,677 1911 Germany ..84/254 Primary Examiner-Richard B. Wilkinson Assistant Examiner-John F. Gonzales Attorney-Melville, Strasser, Foster & Hoffman [57 1 ABSTRACT A hammer butt for use in a piano action, saidhammer butt preferably being molded from plastic and havingan integral socket for receiving the end of a hammer shank which is circular in cross section, the opening in said socket being of a width to engage opposite sides of the hammer shank and of a length greater than the diameter of said hammer shank so that the hammer shank may be tilted relative to the socket so as to bring the hammer shank and the hammer mounted thereon into accurate alignment with the string to be struck by the hammer.

4 Claims, 3 Drawing Figures HAMMER BUTT WITH ADJUSTABLE HAMMER SHANK BACKGROUND OF THE INVENTION A piano action is the mechanism by means of which the strings are caused to be struck upon the depression of the keys. The action is a relatively complicated mechanism involving a number of moving parts, including hammers which strike the strings. The hammers are mounted on hammer shanks which in turn are mounted on hammer butts, the hammer butts being pivotally mounted for movement toward and away from the strings under the influence of the jacks which contact and pivot the hammer butts when the keys are depressed. In

adapted to be inserted in a socket forming a part of the hammer butt, the socket being of a size to snugly receive the shank, which is glued in the socket. Where it is necessary to tilt the hammer shank relative to the socket in order to bring the hammer into alignment with a string, it is the usual practice to manually shave away one side of the shank to the extent necessary to permit it to be tilted within the socket. This is a tedious procedure which is both time consuming and costly. In many instances, the shaved hammer shank will fit loosely in the socket and it is necessary for the worker to hold the hammer shank in its desired inclined position until the glue which holds the shank in the socket has set.

The present invention eliminates the necessity for shaving the hammer shank and at the same time provides a construction which permits the shank to be inclined at the desired angle relative to the hammer butt, the configuration of the socket additionally serving to hold the shank in its inclined position during drying of the adhesive.

RESUME OF THE INVENTION In accordance with the invention, the hammer butts of the action are each provided with a socket having an opening therein which is of a width to engage opposite sides of the hammer shank. To this end, the opposing walls which define the width of the opening are planar and extend parallel to each other. The length of the opening will be greater than the diameter of the hammer shank and, preferably, the opposing wall surfaces defining the length of the opening will be formed on a radius. When inserted in the socket, the hammer shank may be inclined to either left or right of center, thereby permitting it to be aligned with the string with which its hammer is associated.

While the hammer butt itself may take any desired configuration, it preferably will be molded from plastic as a one-piece unit having an integral socket.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary Side elevational view of a hammer butt and hammer shank in accordance with the invention.

FIG. 2 is a vertical section view taken along the line 2-2 of FIG. 1.

FIG. 3 is a sectional view taken along the line 33 of FIG. 2 illustrating alternate positions of the hammer butt and also illustrating alternate positions of the string with which the hammer and shank are to be associated.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, the hammer butt is indicated generally at l, the hammer butt having a socket 2 which receives the hammer shank 3 mounting a hammer 4. While the configuration of the hammer butt does not constitute a limitation on the invention, in the embodiment illustrated it has an integral extension 5 having an abutment 6 adapted to contact the back check of the action. Beneath the socket 2 is a hub 7 having a center bore 8 by means of which the hammer butt is adapted to be pivotally mounted to a supporting flange usually mounted on the action rail of the piano. Intermediate the extension 5 and hub 7 is an abutment portion 9 which is adapted to be covered with a leather piece or other covering (not shown) which is contacted by the jack, the jack acting to pivot the hammer butt about center pin opening 8.

As will be evident from FIGS. 1 and 3, the socket 2 is elongated and comprises an integral part of the hammer butt. While the hammer butt may be made from any desired material, it preferably will be molded from a plastic material, excellent results having been obtained using polyamide resins, generally known as Nylon, either alone or in glass fiber filled condition. Modified phenylene oxide, glass fiber filled resin has also been found to produce excellent results.

As best seen in FIG. 2, the socket is defined by an opposing pair of

planar wall surfaces

10 and 11 lying in parallel relation to each other and defining the width of the opening. Preferably, the width of the opening will be such as to snugly receive the hammer shank 3. To this end, the width of the opening does not necessarily have to be smaller than the diameter of the wooden hammer shank since, prior to its insertion in the socket, the hammer shank will have been dipped in an adhesive which, particularly when using water base adhesives, will effectively increase its thickness. Suffice to say that the spacing between the

wall surfaces

10 and 11 will be such as to engage and hold the hammer shank when it is inserted in the socket.

The length of the opening, as defined by the

walls

12 and 13, will be greater than the diameter of the hammer shank. As illustrated, the

walls

12 and 13 will preferably be of curved configuration, being formed on a radius approximately equal to the radius of the hammer shank. If desired, the

wall surfaces

12 and 13 may terminate at their opposite ends in shoulders l4, l5 and 16, 17, respectively. In any event, the principal consideration is that the length of the opening be greater than the diameter of the hammer shank so that the hammer shank may be tilted or inclined with respect to the centerline of the socket. In this connection, the socket will be so oriented that the

wall surfaces

10 and 11 will lie at essentially right angles to the direction of movement of the hammer when the hammer butt is pivoted about center pin opening 8.

The depth of the opening in the socket is not critical, although it will preferably be sufficiently deep to permit the hammer shank to be well seated and glued in place.

As will be evident from FIG. 3, if the socket 2 is in alignment with the string 18, the hammer shank 3 need not be inclined relative to the socket but may simply project outwardly in axial alignment with the socket. If, however, the socket is not aligned with the string 18, as where the string 18 might occupy the position indicated in dotted lines at 18a, it would then be necessary to incline the hammer shank to the position illustrated in dotted lines at 3a. Similarly, if the string location relative to the socket is as illustrated by the dotted line 18b, it is then necessary to incline the hammer shark in the manner illustrated in dotted lines at 3b. Such inclination of the hammer shank will bring the hammer 4 into alignment with the string positions 18a or 18b when the hammer butt is actuated.

As should now be apparent, the instant invention permits adjusting the movement of the hammer shank without having to shave portions away or otherwise alter its configuration. At the same time, the

opposing wall surfaces

10 and 11 effectively hold the hammer shank in its inclined position during drying of the adhesive which acts to secure the hammer shank in the socket. It also will be evident that modifications may be made in the invention without departing from its spirit and purpose. For example, the shape of the opening in the socket may be varied in size and in geometry, the principal consideration being that the opening have a pair of opposing wall surfaces which will effectively engage and hold the hammer shank therebetween, with the remaining pair of opposing wall surfaces spaced apart by a distance sufficiently greater than the diameter of the hammer shank to permit inclining movement in either direction relative to the centerline of the opening.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a hammer butt for use in a piano action, said hammer butt including an elongated socket for receiving a hammer shank which is essentially circular in cross section, and a hub having a center pin receiving opening therein about which said hammer butt is adapted to pivot, a hammer shank receiving opening in said socket, said opening having a width substantially equal to the diameter of the hammer shank to be received therein and a length which is greater than the diameter of the said hammer shank, the length of the opening in said socket extending in parallel relation to the pivot axis of said hammer butt as defined by said center pin receiving openings, whereby said hammer shank may be inclined in opposite directions relative to the centerline of said socket, in a plane parallel to the length of the opening therein.

2. The socket construction claimed in claim 1 wherein the width of said opening is defined by an opposing pair of planar wall surfaces lying in parallel relation to each other.

3. The socket construction claimed in claim 2 wherein the length of said opening is defined by an opposing pair of arcuate wall surfaces.

4. The socket construction claimed in claim 3 wherein said arcuate wall surfaces terminate outwardly in shoulders abutting the ends of said planar wall surfaces.