US2917962A - Piano-action - Google Patents

Description

Dec. 22, 1959 L. R. BALLET PIANO-ACTION Filed Jan. 9, 1957 United States Patent PIANO-ACTION Lon Raymond Ballet, Courbevoie, France, assignor of seventy percent to Societe Anonyme dite: Pleyel, Paris, France Application January 9, 1957, Serial No. 633,280

Claims priority, application France January 11, 1956 2 Claims. (Cl. 84-242) Piano-actions of conventional or hitherto known types comprise as a rule a wooden cross-member extending throughout the piano width, which is commonly called main action rail and has mounted or pivoted thereon a number of small wooden parts, notably the wippens, jacks, hammer butts and hammer butt buttons, as well as the back check and the damper arms.

In the manufacture of these parts it is customary to firstly stock wood of the proper quality until it attains the necessary dryness, then work it to the desired shape, and finally assemble the parts thus obtained.

This manufacture is extremely costly due on the one hand to the considerable capital tie-up for the wood to be kept in store, and on the other hand to the cost of machining and working these wooden parts and also to the considerable waste occurring inthe manufacture in spite of the great care exerted in both the work and the selection of the wood qualities, not to mention the high cost of assembling and adjusting parts which are never strictly interchangeable and are constantly more or less warping.

To avoid these serious inconveniences while preserving and even improving the operating requirements of pianoaction this invention provides a piano-action characterized in that the main action rail consists of a suitably shaped metal section, and that most of the parts mounted on this rail, notably the wippens, jacks, hammer butts and hammer butt buttons, back checks and damper arms are made of molded plastic material.

Thus, these parts may be mass-produced in a relatively short time without waste and at an extremely low cost; furthermore, these plastic parts are unsensitive to normal temperature variations as well as to the relative humidity of the atmosphere, and their dimensions are extremely accurate so that they can be mounted without difficulty and without requiring any specific adjustment.

Instead of lining the hammer butt and leaving bare the end of the jack co-acting therewith, as in conventional piano-action, it is possible with this invention to use a bare hammer butt associated with a lined jack end portion.

One of the advantages of this arrangement is that it is easier to line the end of the jack than the hammer butt; moreover, the adjustment of these parts is facilitated and the. escapement motion of the jack is improved.

The surface of the hammer butt button which co-acts with the back check may be corrugated to ensure a deeper contact or interengagement of the parts when the back check engages the hammer butt button, as the back check is lined with a soft-felt and leather pad, whereby both parts, i.e. hammer butt button and back check, may engage each other during an undetermined time period sufficient however to enable the jack to recede slightly under the catch of the hammer butt as the key previously depressed resumes its normal, upper position in the keyboard, so as to facilitate the repeating action. The hammer butt button may form an integral unit with the hammer butt.

In order to afford a better understanding of the present invention and of the manner in which the same may be carried out in the practice, reference will now be 'made to the single figure of the attached drawingforming part of this specification and illustrating diagrammatically by way of example in vertical section a typical embodiment of a piano-action constructed in accordance with the teachings of this invention.

In the drawing, the key I mounted in the conventional fashion constantly engages with its rear end the heel 2 of the wippen 3, a felt or cloth pad 4 being interposed between these parts; this wippen 3 is pivoted at 6 in a fork 5 secured by screws 7 to the main action rail 8 consisting of a metal section member of adequate cross-sectional shape, which extends throughout the width of the pianoaction. All the necessary screw-threaded holes are formed in this rail. T

The hammer butt fork 9 and damper fork 10 are also secured by means of screws 11 and 12 on the mainaction rail 8; the fork 9 has fulcrumed therein the hammer butt 13 in which the shank 14 of the hammer peen 15 carrying the felt hammer head 16 is fitted; only the-hammer shank 14 and peen 15 are made of wood, whereas the aforesaid forks 5, 9, 10, whippen 3 and hammer butt 13 are plastic molded parts.

The hammer butt button 17 is formed integrally with the hammer butt 13 and its operating surface 18 intended to co-act with the back check 19 is corrugated; the back check 19, lined with a felt pad '20 covered in turn by a leather srip 21, is carried by a metal rod 22 forcefitted, shrunk or embedded by molding in the wippen 3;

a thin strap 24 has one end secured to the hammer butt button 17 and its other end perforated to receive the point 25 of the metal hook 26 also secured on 'the wippen 3.

In the damper fork 10 the damper arm 27 is pivoted and urged by a damper spring 28 which constantly tends to apply the felt pad 29 of the wooden damper head 30 against the string 31; the damper head 30 is mounted on a plastic damper knob 32 threaded in turn on the upper end of a metal rod 33 having its lower end fitted in a hole formed for this purpose in the upper portion of the damper arm 27, as shown; the metal spoon 34 is threaded or embedded in the rear end of the whippen 3 and co-acts with a felt pad 35 secured to the lower portion of the damper arm 27.

A metal damper rail 36 is carried by rod spindles 37 mounted in bearings 38 secured by screws (not shown) on the main action rail 8; all these parts are made of metal and the damper rail is normally urged against a felt strip 39 secured by screws on the main action rail 8.

The jack 40 of molded plastic material is fulcrumed in a fork 41 molded integrally on the whippen 3.

The jack spring 42 constantly urges the jack 40 against the hammer butt 13; its upper arm co-acting with the hammer butt catch 62 is lined with a piece of leather 43 covering a small felt pad 44; another felt pad 45 is secured on the hammer butt 13, as shown.

The hammer rail 46 carried by the left-hand and righthand arms 47 is adapted to pivot about the axis of a bar 48 mounted on the side members 50; this hammer rail 46 normally rests through a felt pad 49 against the side members 50; its rear face is protected by a metal section 51 and its front face carries felt pads 52 which the hammer shanks 14 engage when they are at rest.

The rotation of the hammer rail 46 and hammer units 14, 15, 16 about the pivot axis 48 of the side arms 47 is controlled in the conventional manner through the soft pedal arm 58 fulcrumed on a pivot pin 59 on either side member 50 of the piano-action; this arm 58 carries a damping pad 60 engaged by an adjustment screw 61 threaded in the bar 46.

The regulating button 53 is also made of plastic molded material and formed at one end of the adjustment screw 54 engaging the wooden rail 55 carried by the metal support 56 secured on the main action rail 8; the jack 40 is provided on its lower arm with a cloth or felt pad 57 adapted to co-act with the relevant regulating button 53.

The operation of this piano-action will be evident to anybody conversant with the art, since it does not differ from that of conventional-type piano-action; the parts are shown in an intermediate position, that is, between the string-striking position in which the hammer head is about to be freed from the jack to contact the string, and the inoperative position in which the hammer shank 14 rests on the hammers rail 46.

What I claim is:

1. A piano action comprising, in combination, a main action rail disposed opposite the piano strings and carrying forks for the pivotal mounting of wippens, hammer butts and damper arms, said main action rail being defined by a metal unit having a transverse cross-sectional profile comprising, when viewed from top to bottom, a first extension extending horizontally in the direction of the strings, a first vertical portion merging at its upper end with said first extension and having at its lower end a horizontal second extension extending away from the strings, a second vertical portion merging at its lower end with a portion which is inclined towards the strings, a third horizontal extension extending away from the strings from the lower edge of said inclined portion, and a third vertical portion extending substantially parallel to the strings from the rear edge of the third horizontal extension, said first horizontal extension being formed with tapped apertures on its upper face, and a damper fork secured to said first extension by screw means engaged' in each of said apertures, said first vertical portion being formed with tapped apertures, and a hammerbutt fork secured to the face of said first vertical portion away from said strings by screw means engaged in each of said apertures, said hammer-butt fork lying above the upper face of said second horizontal extension, a damper rail supported against the face of said second vertical portion facing said strings, and said third vertical portion being formed with apertures, and a Wippen fork secured to said third vertical portion by screw means engaged in each of said apertures, the Wippen fork being disposed between the lower face of said third horizontal extension and the face of said third vertical portion facing said strings.

2. A piano action as defined in claim l, wherein a Wippen is carried in said Wippen fork and said Wippen carries a jack, a hammer-butt engaged by said jack, said hammer-butt having a back-check-engaging portion, a back-check carried by said Wippen, said back-check being provided with a felt pad covered by a leather strap adapted to engage against the back-check-engaging portion of the hammer-butt when said hammer-butt is driven by the jack, said back-check-engaging portion being defined by a surface which has a corrugated profile in cross-section along a plane perpendicular to the main action rail, said surface being positioned to engage the leather strap covering the felt pad of the back-check.

References Cited in the file of this patent UNITED STATES PATENTS 533,469 Jacobi u Feb. 5, 1895 690,784 Soper Jan. 7, 1 902 2,270,426 Farny Jan. 20, 1942 2,469,308 Montoya May 3, 1949 2,542,309 Brown Feb. 20, 1.951 2,571,155 Messant Oct. 16, 1951 FOREIGN PATENTS 196,488 Great Britain Apr. 26, 1923

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