US3583271A

US3583271A - Plastic piano action

Info

Publication number: US3583271A
Application number: US790807A
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: 1969-01-13
Filing date: 1969-01-13
Publication date: 1971-06-08
Anticipated expiration: 1988-06-08
Also published as: GB1273331A; JPS4929447B1; DE2001255A1

Abstract

A piano action wherein major components of the action, including the wippen, hammer butt, hammer jack, damper lever, the back check, and the mounting flanges for the moving parts, are molded from plastic, the construction of the parts eliminating completely the necessity for drilled holes in the parts to receive center pins, spoon shafts and other members normally received in drilled holes.

Description

United States Patent [72] Inventors Merton D. Corwin;

Walter E. Dietrich, both of Cincinnati, Ohio [2]] Appl. No. 790,807 [22] Filed Jan. 13, 1969 [45] Patented June 8, I971 [73} Assignee D. II. Baldwin Company Cincinnati,0hio

[54] PLASTIC PIANO ACTION 17 Claims, 37 Drawing Figs.

[52] 1 US. Cl 84/236, 84/452 [51] Int. Cl Gl0c 3/16 [50] Field ofScarch 84/236- [56] References Cited UNITED STATES PATENTS 1,670,915 5/1928 Volare 84/251 1,650,095 1 1/1927 Rydberg 84/452 2,513,191 6/1950 Martin; 84/240 2,542,306 2/1951 Brown 84/240 3,165,965 1/1965 LoDuca 84/435 3,175,451 3/1965 Klann 84/439 3,422,720 1/1969 Johnson 84/435 FOREIGN PATENTS 104,987 3/1917 Great Britain 84/434 696,924 9/1953 Great Britain 84/236 928,750 6/1955 Germany 84/435 Primary Examiner-Richard B. Wilkinson Assistant ExaminerLawrence R. Franklin Attorney-Melville, Strasser, Foster and Hoffman ABSTRACT: A piano action wherein major components of the action, including the wippen, hammer butt, hammer jack, damper lever, the back check, and the mounting flanges for the moving parts, are molded from plastic, the construction of the parts eliminating completely the necessity for drilled holes in the parts to receive center pins, spoon shafts and other members normally received in drilled holes.

PATENTEDJUN 8l97| 3,583,271

sum 1 or 3 INVENTOR/S ME/QTON D, CO/QW/A/ WALTER E. D/ET/Q/CH ATTOR N EYS PATENIED JUN' BIG?! 3 5 83 271 SHEET 2 BF 3 FISH FIGJZ H613 lNVENTOR/S F1622 FIG. 23 MEMO/V 0, CORW/N c WALTER E. D/ET/Q/CH BY m yum, Z; Max m ATTORNEYS PLASTIC PIANO ACTION BACKGROUND OF THE INVENTION The basic components of piano actions have heretofore generally been made from wood and, due to their intricate nature, are relatively costly to produce. Wood also has the disadvantage of being susceptible to atmospheric conditions and will swell, shrink or warp depending upon the conditions which are encountered.

While it has hitherto been proposed to form the various parts of the action from plastic materials which are essentially insensitive to moisture and hence unaffected by atmospheric conditions, numerous problems have been encountered in the use of plastic materials. If the plastic parts are machined in essentially the same manner as wooden parts, their production cost is equally as high, if not higher, due in part to the difficulty encountered with plastic parts in drilling properly aligned holes and maintaining their tolerances. Even if the plastic parts are molded, difficulties are encountered in subsequently drilling the required holes in the parts. While in some instances molds may be utilized which employ retractable mold pins to define the holes, such expedient is not always practical due to the configuration of the part being molded and the location of the desired hole.

To overcome the difficulties which have been encountered, the instant invention contemplates a piano action in which the operating components comprise one-piece molded plastic parts which may be readily fabricated, the configuration and construction of the parts serving to simplify the action and the number of its operating parts.

The invention also eliminates the necessity for drilled holes in the parts and their attendant problems of alignment and tolerances. This is accomplished in part by the utilization of a wippen construction embodying pockets and pairs of mounting wedges which engage and secure in place rodlike elements which otherwise would require drilled holes, and in part by means of juxtaposed wall surfaces having U-shaped depressions which are aligned to define a circular opening, or by the use of holes defined by sets of open jaws which either directly receive the center pins or engage plastic bearings by means of which the center pins are attached to the plastic parts. While such plastic bearings are not new per se, one form thereof being disclosed in US. Pat. No. 3,186,287, and hence as such do not constitute a part of the present invention, they nonetheless implement the instant invention by providing bearings which are also insensitive to moisture and which may be readily associated with the parts with which they are used.

RESUME OF THE INVENTION A piano action in accordance with the instant invention is composed in large measure of molded plastic parts. While the plastic material from which the parts are formed does not constitute a limitation on the invention, excellent results are obtained using polyamide resins, generally known as Nylon, either alone or in a fiber filled condition.'ABS polymer resins made by combining a styrene-acrylonitrile resin component with a butadiene-acrylonitrile resin have also been found to produce excellent results.

In accordance with the invention, the wippen, the hammer butt, the jack, the damper lever and the back check of the ac tion are all formed as one-piece molded plastic parts, as are the flanges which mount the wippen, the hammer butt and the damper lever. The hammer butt and damper lever flanges are provided with integral means for mounting springs engageable with the hammer butt and damper lever, respectively, to urge them to their normal positions of use.

The wippen is provided with pockets adjacent its opposite ends in which opposing pairs of wedge members are received, the wedge members being configured to define rod receiving cavities therein for mounting a back check rod and a damper actuating spoon. The wippen also includes pin engaging openings for receiving the center pin by means of which the wippen is pivotally connected to its mounting flange and also the center pin to which the jack is pivotally connected. A cylindrical socket is also provided for receiving one end of a jack-biasing coil spring, the latter socket being located adjacent the opening which receives the center pin on which the jack is pivotally mounted.

The jack comprises a unitary plastic member having a bearing receiving open jaw at one end adapted to mount bearings engageable with one of the center pins mounted on the wippen. The jack also has an angularly related arm mounting a barbed projection positioned to engage the opposite end of the coil spring seated in the socket in the wippen, the spring acting to bias the jack so that its opposite end normally engages the hammer butt.

The entire hammer butt is a one-piece member having an integral extension for contacting the back check and a hub for pivotally mounting it to a supporting flange; and the hammer butt is also provided with integral means for attaching patches of padding material, such as buckskin or other leather pieces or the like, which are positioned to be contacted by the jack and the back check. An integral socket is provided to receive an end of the hammer shank, and preferably the socket will be configured so as to securely engage the hammer shank. The hammer butt is also provided with an integral catch adapted to be engaged by one end of a bridle strap, which may be in the form of a plastic strap the opposite end of which engages a similar catch integrally formed in the back check, which is also plastic, the construction eliminating the conventional wire strap holder normally mounted on the wippen adjacent the shank of the back check. In the alternative, the molded back check may be configured so as to receive the end of a cord which serves the function of the bridle strap, the cord extending through an inclined slot in the back check and being wrapped around an integral projecting lug, thereby eliminating the necessity for tying the cord and at the same time providing for ready adjustment ofits length.

The damper lever is also formed from plastic and is mounted to the action supporting rail by means of a plastic flange incorporating spring means acting to bias the damper carried by the arm into engagement with the key. The damper lever preferably incorporates a pin receiving hole formed by juxtaposed wall surfaces having mating Ushaped depressions.

All of the parts of the action are adapted to be mounted on a single rail member, which preferably is made of aluminum and provided with mounting surfaces to which the wippen, hammer butt and damper lever flanges may be readily secured.

DESCRIPTION OF THE DRAWINGS FIG. I is a side elevational view of a piano action constructed in accordance with the instant invention.

FIG. 2 is an enlarged side elevational view of the wippen.

FIG. 3 is a top plan view of the wippen.

FIG. 4 is a bottom plan view of the wippen.

FIG. 5 is a side elevational view showing the coacting spoon wedges in side-by-side relation as they are initially molded.

FIG. 6 is an end elevational view of the leftmost wedge section taken from the left side of FIG. 5.

FIG. 7 is an end elevational view of the rightmost wedge section taken from the right side of FIG. 5.

FIG. 8 is an end elevational view illustrating the two wedge sections joined together for insertion in the wippen.

FIG. 9 is a fragmentary sectional view taken along the line 9-9 of FIG. 4 illustrating the engagement of the wedges in their pocket in the wippen.

FIG. 10 is a side elevational view similar to FIG. 5 but illustrating the wedge sections utilized in conjunction with the back check rod.

FIGS. 11 and 12 are end elevational views corresponding to FIGS. 6 and 7 but illustrating the wedges for the back check rod.

FIG. 13 is a side elevational view of the assembled wedge sections illustrated in FIGS. ll0-12.

FIG. 14 is a fragmentary vertical sectional view taken along the line 14-14 of FIG. 4 illustrating the back check wedges inserted in their pocket in the wippen.

FIG. is a side elevational view of the hammer butt assembly.

FIG. 16 is an end elevational view taken from the right side of FIG. 15.

FIG. 17 is an end elevational view taken from the left of FIG. 15.

FIG. 18 is a side elevational view of the wippen mounting flange.

FIG. 19 is a front elevational view taken from the right side of FIG 18. v

FIG. is a fragmentary elevational view illustrating the manner in which the hammer butt is mounted to its supporting flange, including the bearings for the center pin and the spring means for biasing the hammer butt to its normal position of use.

FIG. 21 is a fragmentary elevational view similar to FIG. 20 but taken from its opposite side.

FIG. 22 is a side elevational view of the jack.

FIG. 23 is a front elevational view of the jack taken from the right side of FIG. 22.

FIG. 24 is a side elevational view of the damper lever.

FIG. is a plan view of the damper lever taken from the left side of FIG. 24.

FIG. 26 is a plan view of the damper lever taken from the right side of FIG. 24.

FIG. 27 is an enlarged fragmentary view of the central portion of the damper lever illustrating the manner in which the center pin opening is formed therein.

FIG. 28 is a fragmentary sectional view taken along the line 2828 of FIG. 25.

FIG. 29 is a side elevational view of the damper lever mounting flange.

FIG. is a top plan view of the damper lever flange.

FIG. 31 is a fragmentary view taken along the line 31-31 of FIG. 1 illustrating the spring biasing of the damper lever.

FIG. 32 is a side elevational view of a back check incorporating means for engaging a bridal cord.

FIG. 33 is an elevational view taken from the left side of FIG. 32.

FIG. 34 is an elevational view taken from the right side of FIG. 32.

FIG. is a bottom plan view of the back check.

FIG. 36 is a top plan view of a modified form of hammer butt assembly in which the hammer shank-receiving socket is provided with shank engaging ribs.

FIG. 37 is an enlarged fragmentary vertical sectional view taken along the line 37-37 of FIG. 36.

DESCRIPTION OF THE PREFERRED EMBODIMENT The general organization or arrangement of parts is illustrated in FIG. 1, wherein it will be seen that the action is mounted on a supporting rail 1 which is preferably in the form of an aluminum extrusion extending lengthwise of the piano. At its lowermost extremity the rail mounts a wippen flange 2 to which the wippen 3 is pivotally connected in a manner which will be explained in greater detail hereinafter. Intermediate its ends the wippen pivotally mounts ajack 4 the opposite end of which contacts the hammer butt 5 also pivotally connected to rail 1 by means of hammer butt flange 6. The hammer butt mounts a conventional hammer shank 7 having a hammer 8 at its distal end movable in an arcuate path to strike a vertically disposed string 9.

The hammer butt has an integral extension 10 adapted to contact the back check 11 which is mounted on a rod 12 projecting upwardly from the wippen. A bridle strap 13 extends between the hammer butt extension 10 and the back check 11 to limit pivotal movement of the hammer butt assembly and also hold the parts together when the action is removed from the piano.

The rail 1 also mounts a damper flange 14 to which the damper lever 15 is pivotally secured, the uppermost end ofthe damper lever mounting a damper shank 16 to which the damper 17 is attached, the damper normally contacting the string 9. At its opposite end the damper lever 15 is positioned to be contacted by a spoon 18 projecting upwardly from the wippen 3, the arrangement being such that movement of the wippen in a clockwise direction will cause the damper lever to withdraw the damper from contact with the string, which movement occurs as the hammer is advanced to strike the string.

In the embodiment illustrated, the wippen is capstan actuated by means of the key 19 having its rear portion underlying the wippen, the key being mounted on the key bed 20. It will be understood, however, that where the piano is of the drop action type wherein the action lies beneath the plane of the keys. the wippen may be sticker actuated by means of the sticker diagrammatically indicated at 21.

When the key is struck, the wippen 3 pivots in a clockwise manner about the flange 2, thereby moving the jack 4 upwardly. The upward movement of the jack causes the hammer butt 5 to pivot in a clockwise direction relative to the hammer butt flange 6, thereby causing the hammer to strike the string. The jack is spring-biased into contact with the hammer butt by means of the coil spring 22 extending between the wippen 3 and the arm 23 forming an integral part of the jack. However, as will be understood by the worker in the art, the jack is released from contact with the hammer butt by means of the letoff means 24 which contacts the arm 23 and causes the jack to pivot in a counterclockwise direction, thereby freeing the hammer to return to rest against the hammer stop 25 under the influence of the hammer butt spring 26. The pivotal movement of the wippen also rocks the damper lever arm 15 to withdraw the damper 17 from contact with the string; the damper will remain withdrawn until the key is released, whereupon the damper spring 27 urges the damper into contact with the string.

The Wippen As seen in FIGS. 2, 3 and 4, the wippen 3 comprises an elongated one-piece molded member having a wedge-shaped pocket 30 at one end and a wedge-shaped pocket 31 adjacent its opposite end beyond which projects a hook 32 which may be employed to engage the lowermost end of sticker 21 (FIG. 1) in the event the instrument is sticker actuated. A socket 33 lies adjacent the pocket 31 to receive the lowermost end of jack spring 22; and a ledge 34 underlies the socket to which a cushion 35 is secured, the cushion being positioned to be contacted by the capstan screw 36 in the event the instrument is capstan actuated.

In the embodiment illustrated, an upstanding post 37 is provided with a pair of open jaws 38 of a size to engage the center pin 38a (FIG. 1) on which the jack 4 is pivotally mounted. Similarly, a downwardly opening pair ofjaws 39 is adapted to engage the center pin 40 (FIG. I) by means of which the wippen is pivotally connected to the wippen flange 2. The portion of the wippen overlying the jaws 39 is preferably rounded, as indicated at 41, to facilitate pivoting movement of the wippen between the arms of the wippen flange 2, which will be described in detail hereinafter.

The pocket 30 is adapted to receive the coacting pair of

wedges

42 and 43 illustrated in FIGS. 5 through 8, which are also formed from plastic. For convenience in handling, the wedges are preferably connected together by a flexible strap 44 formed from the same plastic material as the wedges themselves, the strap being formed as an incident of the molding operation. The wedges terminate at their lowermost ends in out-turned

abutments

45 and 46, respectively, the wedges also having

mating channels

47 and 48 formed therein which are semicircular in cross section. Wedge 42 is also provided with a peg 49 adapted to be received in an aligned opening 50 in wedge 43 when the wedges are juxtaposed in face-to-face relation. The assembled wedges are shown in FIG. 8. Whilethe flexible straps are a convenience in handling the wedges, they may be omitted if desired; and the pegs 49 and their mating openings 50 also may be omitted.

The

wedges

42 and 43 serve, when inserted in pocket 30, to mount the spoon 18, the distal end ofthe spoon being received in the

mating channels

47 and 48 in the manner illustrated in FIG. 9. Preferably, the wedges will be engaged with the spoon prior to their insertion in the pocket 30, whereupon the assembly will be inserted and the wedges forced downwardly until their

abutments

45 and 46 engage the undersurface of the wippen adjacent the lowermost end of pocket 30, locking the wedges in place. Normally the distal end of the spoon 18 will be forced into biting engagement with the

mating channels

47, 48. The use of this wedge assembly permits the spoons to be assembled to the wippens with the spoons inclined either to the right or to the left, or omitted, as required. This allows the molding of wippens of a single design with attendant advantage in the elimination of molding and stocking both righthanded and left-handed wippens.

Somewhat similar wedges are utilized to secure the back check rod 12 in pocket 31; and for convenience of description like parts have been given like reference numerals. In this instance, however, it is preferred to provide the pocket 31 with an internal ledge 51 (see FIGS. 2 and 3) and consequently the

back check wedges

52 and 53 are provided with mating shoulders 54 and 55, respectively, which are adapted to seat on the ledge 51, thereby providing additional rigidity and stability. As before, the

channels

47 and 48 will engage about the lowermost end of the rod 12; and the

abutments

45 and 46 will lock beneath the undersurface of the wippen to lock the wedges in place.

The Hammer Butt Referring next to

FIGSv

15, 16 and 17, the hammer butt is also a one-piece molded part of complex configuration, having a center pin receiving hub 60 at one end thereof, the hub having a center bore 61 on one side and an open jaw 62 on its opposite side, the arrangement facilitating the molding of the parts. An elongated socket 63 extends in the opposite direction and receives the distal end of the hammer shank 7, which normally will be formed from wood and glued in the socket 63.

The hammer butt also includes an abutment portion, indicated generally at 64, adapted to be covered with a leather piece or the like 65 contacted by the free end of jack 4. In order to facilitate the attachment of the leather piece 65, the abutment64 may terminate at its opposite ends in slots 66 and 67 having

barblike projections

68 and 69 which bite into the ends of the leather piece inserted in the slots 66 and 67. The abutment is also preferably cut away to provide depressions 70 and 71 adapted to receive additional cushioning material so as to round out and pad the abutment.

Similarly, the extension of the hammer butt is provided with an abutment 72 positioned to contact the back check 11, the abutment 72 terminating at its opposite ends in

slots

73 and 74 having barblike projections 75 and 76, which engage the opposite ends of the leather or felt piece 77 which cushions the abutment. It will be understood that while the barblike projections hold the ends of the cushioning pieces in the slots, it is preferred that adhesive also be employed to secure the ends of the pieces firmly in place. Where the size of the cushioning material is such as to cause bunching when inserted in the slots, some or all of the slots and barbs may be omitted and the cushions secured in place solely by adhesive.

The extension 10 may be provided with a button 78 which engages one end of plastic bridle strap 13, the strap having a slit adjacent its end edge of a size to fit over the button. In addition, the body of the hammer butt is provided with a lug 79 (FIG. 16) which acts as a retainer for one end of the hammer butt spring 26, which will be discussed in greater detail in conjunction with the hammer butt flange 6 which will now be described.

Wippen and Hammer Butt Flanges The wippen flange 2 and the hammer butt flange 6 are essentially identical and, as seen in FIGS. 18 and 19, each comprises a flange body 80 having

yoke defining arms

81 and 82 which in turn define pairs of

open jaws

83, 84 of a size to receive the plastic bearings which mount the center pin. A bore 85 extends through the body of the flange from front to rear opening on one side into a recess 86 which, as will be apparent from FIG. 1, engages a mating projection on the supporting rail 1. Suitable mounting screws 87 and 88 serve to fixedly secure the

flanges

2 and 6, respectively, to the supporting rail; and preferably the flanges are provided with a projection 89'which seats against an angularly disposed portion of the supporting rail. Where the flange is utilized to mount the hammer butt 5, it is also provided with a slot 90 (FIG. 19) for receiving an end ofthe hammer butt spring 26.

The manner in which the hammer butt is mounted on the flange 6 is illustrated in FIGS. 20 and 21, wherein it will be seen that the

jaws

83 and 84 engage

plastic bearings

91 and 92 which receive the ends of center pin 93 which will previously have been passed through the center bore 61 in center pin hub 60. The hammer butt spring 26 is wrapped around hub 60 in the manner illustrated, having one end juxtaposed to the hammer butt adjacent lug 79 and its opposite end received in the slot 90 in the flange, the biasing of the spring being such that the hammer butt will be normally biased to its position of rest, which is shown in FIG. 1.

It will be understood that the wippen will be mounted on flange 2 in essentially the same manner, i.e., the center pin 40 being received in a pair of bearings corresponding to the

bearings

91 and 92 engaged in the

jaws

83 and 84. In this instance, however, a spring need not be provided to bias the wippen.

The Jack The jack 4 is illustrated in FIGS. 22 and 23 and comprises, in addition to the arm 23, a pair of spaced-apart depending

arms

94 and 95 having bearing receivingjaws 96 and 97 which connect the jack to center pin 39 (FIG. 1). At its opposite end, the jack is provided with an abutment portion 98 which contacts the leather piece 65 covering the abutment 64 on the hammer butt. The arm 23 ofthejack mounts a barbed stud 99 on its undersurface which engages the uppermost end of the spring 22 (see FIG. 1) which acts to urge the jack into contact with the aforementioned abutment on the hammer butt.

The Damper Mechanism The principal component of the damper mechanism is the damper lever 15 which is illustrated in detail in FIGS. 24 through 28. It also comprises a unitary molded member in which the center pin receiving opening 100 is formed without using a molding pin. This is accomplished by forming three juxtaposed wall members at the center of the lever, the

outermost wall members

101 and 102 having

U-shaped depressions

103 and 104 formed therein, the depressions being aligned with an oppositely directed depression 105 formed in intermediate wall member 106. By such expedient, the circular opening 100 is defined without need for a drilling operation or the use of a molding pin in the mold in which the part is formed.

To reduce its mass, while at the same time provide adequate rigidity, the lever is preferably of channel-form construction having opposing wall surfaces 107 and 108 projecting in one direction and terminating at their free end in a socket 109 adapted to receive the end of damper shank 16. The same end of the lever also has a hollowed scooplike portion 110 which receives an end of the damper spring, as will be evident from FIG. 1.

The opposite end of the lever arm has opposing

walls

111 and 112 joined together by a planar wall portion 113 which forms a seat for the cushioning material 114 adapted to be contacted by spoon 18.

.each other.

The damper flange 14 is also shown in FIGS. 29 and 30, the flange having a body 115 having opposing

arms

116 and 117 in which open

jaws

118 and 119 are formed, it being understood that the jaws will mount bearings for the center pin 120 (FIG. 1) on which the damper lever is mounted, the center pin passing through the opening 100.

The flange 14 is also provided with a bore 121 for the passage ofa mounting screw and adjacent the bore is a groove 122 for engaging a mating projection on the supporting rail]. The arm 117 is provided with a spring receiving lug 123 and a slot 124 for receiving an end of the spring 27, the spring 27 being mounted in the manner illustrated in FIG. 31, wherein it will be seen that several convolutions of the spring are fitted over the lug 123 with one end of the spring seated in the slot 124 and its opposite end extending upwardly for contact with the scooplike portion 110 of damper lever 15.

The Back (heck It is also preferred that the back check 11, as shown in H6. 1, be formed from plastic, including an integral catch 125 for engaging the opposite end of the bridal strap 13. The back check will also be provided with a suitable cushion 126 positioned to be contacted by the cushioned abutment 72 on hammer butt extension 10.

When it is desired to utilize a cord instead of the bridal strap, the back check may be constructed in the manner illustrated in FIGS. 32 through 35. As seen therein, the back check has a body 127 with an enlarged face 128 mounting the cushion material 126. A pair of

cars

129 and 130 project outwardly from the opposite sides of the body 127; and a post 131 projects downwardly therefrom to the rear of the rod receiving opening 132.

Slots

133 and 134 are cut in the undersurface of face member 128, the slots inclining outwardly and opening at the rear surface of face 128 immediately beneath the

ears

129 and 130.

With the arran'gementjust described, it has been found that a bridal cord 135, as illustrated in dotted lines in FIG. 32, may be passed through either of the

slots

133, 134, then upwardly around the adjoining ear and then downwardly and around the post 131 to effect a tight nonslip connection. Thus, the length of the bridal cord extending between the hammer butt and the back check may be easily and quickly adjusted.

Various additional modifications may be made in the invention without departing from its spirit and purpose. For example, FIGS. 36 and 37 illustrate a modification in the hammer receiving socket of the hammer butt, the socket having a rectangular first bore 135 provided along its corners with ridges 136 which have been found particularly suited for holding the hammer shank in proper position during gluing, the areas adjoining the ridges providing space for sufficient adhesive to insure a good bond. At its lowermost end, the socket has a cylindrical bore 137 into which the lowennost end of the hammer shank may be seated to hold the wooden shank in place while the adhesive is drying. Such construction permits the socket to'be readily molded and yet provides means for holding the hammer shank in place in the desired position while the adhesive sets to firmly bond the shank in the socket.

Modifications also may be made in the flanges and in the wippen without departing from the spirit of the invention. Thus, in the flanges the pairs ofjaws which engage the center pin bearings may be replaced by through holes which may be molded in the yoke defining arms by means of pins, thereby again eliminating the necessity for drilled holes in the parts. 1n addition, the raised portions of the supporting rail 1 which are engaged by the flanges may be serrated longitudinally so as to bite into the plastic flanges when they are tightened; and to this end the recesses 86 in the flanges may be either eliminated or else configured to be wider than the portions of the raised rail which they engage, so that the flanges may be pivoted laterally about their mounting screws. such as the screws 87, 88, to effect adjustment and alignment of the parts relative to Other modifications of the invention will undoubtedly occur to the skilled worker in the art upon reading this specification; and accordingly it is not intended that the invention be limited other than in the manner set forth in the claims which follow.

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

We claim:

1. For use in a piano action, a one-piece molded plastic wippen comprising an elongated body having a pair of spaced apart pockets therein, and coacting pairs of wedges adapted to be inserted in said pockets, said pairs of wedges having mating channels therein defining shaft receiving openings.

2. The plastic wippen claimed in claim 1 wherein said pockets are of wedge shape, and the said pairs of wedges are correspondingly shaped to be received in said pockets.

3. The plastic wippen claimed in claim 2 wherein said pockets extend completely through said wippen, wherein said wedges terminate at their lowermost ends in out-turned abutments engageable with said wippen beyond the ends of said pockets.

4. The plastic wippen claimed in claim 1 wherein the wedges are formed from a plastic material, and wherein the wedges in each pair are connected together by a flexible strap formed from the same plastic material as the wedges themselves.

5. The plastic wippen claimed in claim 1 wherein one of the wedges in each pair is provided with a peg adapted to be received in an aligned opening in the other wedge in the pair when the wedges are juxtaposed in face-to-face relation.

6. The plastic wippen claimed in claim 1 wherein at least one of the pockets in said wippen is provided with an internal ledge, and wherein the pair of wedges received in said last named pocket is provided with mating shoulders adapted to seat on said ledge.

7. The wippen claimed in claim 1 including at least one pair ofopen jaws adapted to engage a center pin.

8. For use in a piano action, a one-piece molded plastic hammer butt having a body mounting a center pin receiving hub, and at least one abutment adapted to be covered by a piece of leather, a slot at one end at least of said abutment for receiving an end of the leather piece, and a barb in said slot for engaging the inserted end ofthe leather piece.

9. The plastic hammer butt claimed in claim 8 including a slot at the opposite end of said abutment for receiving the opposite end of the leather piece, and a barb in said last named slot.

10. The hammer butt claimed in claim 9 wherein said hammer butt includes a spaced apart pair of said abutments.

11. The hammer butt claimed in claim 8 including an elongated socket for receiving a hammer shank, said socket being of generally rectangular configuration but having ribs at the corners thereof adapted to engage the end of the hammer shank.

12. The hammer butt claimed in claim 11 wherein said socket terminates inwardly in a cylindrical bore of a size to receive the hammer shank.

13. For use in a piano action, a one-piece molded plastic part having a body defined in part by a plurality ofjuxtaposed wall members each having an open-ended slot formed therein, the slots in adjacent wall members being oppositely directed and positioned with their innermost ends in overlapping relation to define an opening extending through said juxtaposed wall members.

14. The plastic part claimed in claim 13 wherein said part comprises an elongated damper lever having a socket at one end and a seat at the opposite end for mounting a pad of cushioning material.

15. The damper lever claimed in claim 14 wherein the end of said lever having said socket also includes a wall surface havinga hollowed scooplike portion adapted to receive the end ofa damper spring.

16. For use in a piano action, a one-piece molded plastic back check comprising a body having a socket therein for receiving the end of a mounting rod, and means for attaching 17. The back check claimed in claim 16 wherein said back an end ofa bridle cord thereto, said means comprising a slot in Check h a i f ars rojecting outwardly from the op the undersurface of said back check, an ear projecting outwardly from said back check adjacent one end of said slot, and

a post projecting downwardly from the undersurface of said 5 back check.

posite sides thereof, and wherein there is a slot in the undersurface ofthe back check in alignment with each of said cars.

Claims

7. The wippen claimed in claim 1 including at least one pair of open jaws adapted to engage a center pin.

8. For use in a piano action, a one-piece molded plastic hammer butt having a body mounting a center pin receiving hub, and at least one abutment adapted to be covered by a piece of leather, a slot at one end at least of said abutment for receiving an end of the leather piece, and a barb in said slot for engaging the inserted end of the leather piece.

13. For use in a piano action, a one-piece molded plastic part having a body defined in part by a plurality of juxtaposed wall members each having an open-ended slot formed therein, the slots in adjacent wall members being oppositely directed and positioned with their innermost ends in overlapping relation to define an opening extending through said juxtaposed wall members.

15. The damper lever claimed in claim 14 wherein the end of said lever having said socket also includes a wall surface having a hollowed scooplike portion adapted to receive the end of a damper spring.

16. For use in a piano action, a one-piece molded plastic back check comprising a body having a socket therein for receiving the end of a mounting rod, and means for attaching an end of a bridle cord thereto, said means comprising a slot in the undersurface of said back check, an ear projecting outwardly from said back check adjacent one end of said slot, and a post projecting downwardly from the undersurface of said back check.

17. The back check claimed in claim 16 wherein said back check has a pair of ears projecting outwardly from the opposite sides thereof, and wherein there is a slot in the undersurface of the back check in alignment with each of said ears.