US3171320A - Piano action - Google Patents

Description

MalCh 2, 1965 J. E. UNDIERwooD. JR l 3,171,320

PIANO ACTION Filed March 15, 1961 INV EN TOR Julius E UnderwoodJf United States Patent O 3,171,320 PIANO ACTION Julius E. Underwood, Jr., Essex, Conn., assgnor to Pratt,

Read & Co., Incorporated, Ivorytou, Conn., a corporation ofvConuecticut.

Filed, Mar. 15, 1961, Ser. No. 95,984 8 Claims. (Cl. 84-240) This invention relates generally to pianov actions and more particularly to an improved lifter abstract` and sticker guide assembly for a piano action.

A lifter abstract is ordinarily removably held4 in the yoke of a sticker guide which is in turn fixed to a. piano key in some suitable manner. In the design and assembly of a lifter abstract and sticker guide it is of theutmost importance to provide fast and smooth operation. In addition, to this, once the assembly has been incorporated into the actiony and the actionl has been assembled into a piano, servicing isY required from time to time. In the past, difficulty has been encountered in separating the lifter abstract and sticker guide by virtue of their construction. Also, in some cases when the lifter abstract ismoved from its position within thev yoke of thesticker guidethe retaining member would slip down the lifter abstract thereby making it difficult to replace the abstract in position within the sticker guide yoke.

Lifter abstracts for piano actions are presently being manufacturedV asstraight Wooden, members bushed with a wool cloth and pinned at the bottom to form a pivot point with the whippen. At the key end the lifter abstract is ordinarily connected by a sticker guide. In any event, a wool cloth or felt was used at the pivot point. It has also been a practice to utilize a straight wire inserted into an elbow which was alsobushed with wool cloth and pinned to the whippen. The tops ofv these wires would commonly be threaded and fitted with metal nuts or threaded Wooden dowels. In. forming the topl portion in this manner a` wool cloth or felt had to be used to quiet the pivot point.

It is therefore. an object of the present invention to provide an improved piano action. lifter abstract and sticker guide assembly.

Another object of the present invention is` to provide a piano action lifter abstract and. sticker guide assembly having inexpensive and noiseless pivotal connections and engaging wear surfaces.

A further object of this invention is to providea new and improved regulating nut assembly.

A feature of the present invention is the provision of piano. action parts having engaging surfaces coated with aL resilient material to aord maximum noise reduction and. relatively smooth operation therebetween.

Another feature of the present invention is the provision of. piano, action abstract` and sticker guide assemblies wherein the engaging parts arecoated with a plastic material to. mufe noise and reduce friction at the coated surface area.

Still. another feature ofthe present invention is the prof vision of a metal wire abstract having a regulating nut threadably disposed thereon with a plastic material about the wire and nut which engagesy the yoke of a sticker guide.

ramp. is formed. uponv the cap portion terminating at the groove.

3,171,320 Patented Mar. 2, 1965 'ice Another feature of this invention is the provision of a regulating nut threadably disposed upon one end of an abstract and having a molded resilient material disposed over the regulating nut and having a groove formed in the molded resilient material to receive the forked end portion of a sticker guide fixed to a piano key, with. the material frictionally engaging the abstract to provide controlled torque resisting movement of the regulating nut.

It isa further feature of this invention to provide a flat metal wire abstract having one end pivotally mounted upon one end of a whippen and having a regulating nut threadably disposed upon its other end wherein a plastic material is disposedl over the nut and the abstract adjacent thereto to afford. an engaging surface within a coated forked sticker guide in a piano key.

Another feature of the present invention is the provision of a plastic` coating comprising a polyvinyl chloride resin dispersed in a plasticizer disposed upon a regulating nut and an upper portion of an abstract to provide a controlled adjustment thereto.

Referring to the drawings:

FIG. 1 is an elevation view of a piano action incorporating-the features of the present invention;

FIG. 2 is aA fragmentary view of a modified construction of the piano action of FIG. l;`

FIG. 3 is a fragmentary view of a lifter abstract and sticker guide for a piano action;

FIG. 4 is a top planv view of a sticker guide;

FIG. 5 is an enlarged sectional View of the upper portion of a, piano action abstract; and

FIG. 6 is an enlarged sectional View of a modied form of the abstract of FIG. 5.

The piano action in accordance with this invention provides an improved lifter abstract and regulating nut assemblyv for use with a sticker guide which has a yoke or forked shaped end portion. The portion of the lifter abstract having the regulating nut threadably mounted thereonr is covered with a plastic material which tends to prevent rotation thereof and in addition provides for controlled accurate adjustment of the regulating nut. It will be understood that the plastic material referred to herein may comprise any resilient material suitable for the application disclosed such as rubber, synthetic rubber or other plastic4 materials. The plastic material may be molded prior to assembly upon the lifter abstract. In such case, during the molding process an annular groove is formed` in the plastic material, which groove is provided to receive the forked end portion of the lifter guide. The molded plastic cap portion is forced over the regulating nut which is threadably mounted upon the abstract, and the cap portion is thereby in engagement with the lifter abstract.

The plastic coating may also be providedv by dipping the lifter abstract in a plastic material. The part to be coated is iirst heated and then immersed in a polyvinyl chloride resin which is dispersed in a suitable plasticizer. The part is then heated a second time to fuse the plastic thereupon.

The sticker guide may be removed from engagement with, the lifter 'abstractr by lifting it in an upward direction and outwardly from the plastic covered lifter abstract end portion. The sticker guide may have a light coating of ak plastic material, in order to reduce friction at the engaging surfaces. The lower end of the abstract may also be coated with a plastic material in order to aiford a noiseless bearing for a pin in couplingl the abstract to a whippen.

It willk be understood that any resilient material may be used for the regulating nut covering and the only requirements are that if the material is to be molded annees ably received in the fork of a sticker guide 12 which is 4in turn fixedly disposed in the key 13.

It will be seen that the sticker guide 12 (FIG. 4) is formed of a substantially liat piece of metal having a fork end portion and fin the process of manufacture, the opposite end portion is twisted to lie in a plane at 90 with respect to the yforked end portion. This sticker guide is forced into the body of the key 13 as seen in FIG. l, andy is removed from engagement with the lifter abstract 11 by rotating to VVfree the fork from a groove 15 formed in the cap portion 14 which is disposed over a regulating nut 16 upon the lifter abstract 11.

The regulating nut 16 is threadably disposed at the upper end of the abstract 11. This regulating nut 16 may be of any suitable material. The molded cap portion 14 is disposed upon the regulating nut 16 and upper portion of the abstract 11. The cap portion 14 is seen in cross-section in FIG. 5. An annular ramp 17 is formed Von the cap 14 and terminates at its highest point in a lip 18. In assembling the lifter abstract 11 to the sticker guide 12, the forked end of the sticker guide 12 is forced up the ramp 17 over the lip 18 and into the groove 14 by action of key 13.

In a modified form, the lifter abstract may have an L- shaped body portion 24 (FIG. 2) in which an end portion is adapted to threadably receive a regulating nut and plastic coating 23 thereon. In this modification the plastic coating is applied by dipping the lifter abstract into the plastic material. plastic upon the part and the part is subsequently cooled. This construction is shown in more detail in FIG. 6. Although providing basically the same characteristics as the lifter abstract assembly of FIG. l the method of disposing the resilient material'upon the lifter abstract of FIG. 2 differs from that wherein the resilient material cap portion 14 is forced over the regulating nut after having been molded.

It will be noted in FIGS. l, 2 and 3 that the lower portion of the lifter abstract is pivotally mounted upon a whippen and in -all three instances the lower end por- -tion is coated with the plastic material at the pivot point. In FIG. 1 the lower end portion of the abstract 11 is coated with a plastic material 22 and pinned to the whippen 21, in FIG. 2 the lower end portion of the abstract 24 is coated with a plastic material 23 and pinned to the whippen 19, and in FIG. 3, the lower end portion of the abstract 26 is coated with a plastic material 25 and pinned to the whippen 27.

In all of the embodiments shown the sticker guide 12 may be coated with a plastic material to reduce friction at the engaging surfaces.

The invention provides therefore a piano action having a lifter abstract and sticker guide assembly which are adapted to afford the lower coefficient of friction at the engaging surface and tend to reduce noise so that a piano action may function in an improved manner. Specifically, the upper portion'of the lifter abstract has a regulating nut threaded thereon and a resilient material disposed over the regulating nut, and wherein the upper portion is pivotally mounted within the forked portion of the sticker guide. Torque applied to the regulating nut may be accurately controlled by virtue of the resilient material ldisposed over the nut and upon the threaded portion of the abstract above and below the nut. The sticker The abstract is then heated to fuse the t guide may also be thinly coated with a plastic material to facilitate the action between it and the lifter abstract. The lower end portion of the lifter abstract may be coated with a plastic material similar to that coated upon the upper portion and pivotally pinned to the whippen of the action.

I claim:

l. In a piano action, a lifter abstract having an elongated body portion with a threadedvend portion, a regulating nut threadably disposed upon said end portion, said nut being freely rotatable'upon said threaded end portion, and a plastic coating disposed upon said end portion and engaging said threads thereof, said plastic coating at least upon said end portion, and a member made of plastic material disposed over said regulating nut and engaging said threaded end portion for resisting rotation of said nut with respect to said end portion, said plastic member having a bearing surface for engagement with the sticker guide of the key.

3. In a piano action a lifter abstract comprising a body portion having one end with a plastic coating disposed thereon and an other threaded end, `a regulating nut threadably disposed upon said lother end of said lifter abstract, and a plastic coating disposedv over said regulating nut and upon said threaded end of said lifter abstract, said plastic coating engaging the threads of said abstract and said regulating nut for resisting rotation of said regulating nut with respect to said abstract, said plastic material comprising a polyvinyl chloride resin dispersed in a suitable plasticizer.

4. In a piano action including a forked sticker guide member, a regulating nut assembly comprising an externally threaded body portion, a nut threadably disposed upon said body portion, and a resilient cap mounted u'pon said threaded body portion and having a part extending over said nut, said resilient cap engaging the threads on said body portion and resisting rotation of said'nut with respect to said body portion, said resilient cap being formed with an annular groove adapted to receive the fork portion of the sticker guide member.

5. In a piano action, the combination 'of a lifter abstract for operation with a piano key, said abstract including an elongated body portion formed with a threaded end portion at one end thereof, a regulating nut threadably received upon said threaded end portion, a cap portion formed of resilient material having a portion disposed over said regulating nut upon said end portion, said cap portion engaging the threads of said end portion for resisting rotation of said regulating nut with respect to said end portion, said cap being formed with an annular groove therein below said portion -over said regulating nut and having a ramped end portion leading from said groove, and a sticker guide adapted to be fixed at one end to the piano key wherein said sticker guide is pivotally received in said annular groove, said stickerguide being insertable into said groove by moving up along said ramped end portion.

6. In a piano action, a lifter abstract for coupling a.,Y

piano action whippen assembly to a piano key, saidab" stract including a body portion, a threaded end portion, mounted in said body portion, a regulating nut thread-, i

justment of said nut is accurately controlled.

8. A regulating nut substantially in accordance with claim 7 wherein said plastic cap portion comprises poly- 15 vinyl chloride resin dispersed in a suitable plasticizer.

710,530 Great Britain June 16, 1954

Claims (1)

1. IN A PIANO ACTION, A LIFTER ABSTRACT HAVING AN ELONGATED BODY PORTION WITH A THREADED END PORTION, A REGULATING NUT THREADABLY DISPOSED UPON SAID END PORTION, SAID NUT BEING FREELY ROTATABLE UPON SAID THREADED END PORTION, AND A PLASTIC COATING DISPOSED UPON SAID END PORTION AND ENGAGING SAID THREADS THEREOF, SAID PLASTIC COATING AT LEAST PARTIALLY COVERING SAID REGULATING NUT AND ACTING TO RESIST

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