US3319503A

US3319503A - Piano action assembly

Info

Publication number: US3319503A
Application number: US288993A
Authority: US
Inventors: Charles S Corey
Original assignee: Wurlitzer Co
Current assignee: Wurlitzer Co
Priority date: 1963-06-19
Filing date: 1963-06-19
Publication date: 1967-05-16
Anticipated expiration: 1984-05-16

Description

May 16 1967 c. s. coREY PIANO ACTION ASSEMBLY 5 Sheets-Sheet l Filed June 19, 1963 INVENTOR.

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PIANO ACTION ASSEMBLY 3 Sheets-8heet 2 Filed June 19, 1963 VENTOR BY /fw/ m@ May 16, 1967 c. s. coREY PIANO ACTION ASSEMBLY 5 Sheets-Sheet 5 Filed June 19, 1963 www www 9g l JW mmm u 1 N VEN TOR. CaW/wCO/ey mwN 81 United States Patent 3,319,503 PIAN() ACTION ASSEMBLY Charles S. Corey, De Kalb, Ill., assigner to The Wurlitzer Company, Chicago, Ill., a corporation of Ohio lFiled .lune 19, 1963, Ser. No. 288,993 22 Claims. (Cl. 84--240) This invention relates generally to pianos and analogous musical instruments and relates more particularly to ac tion mechanisms for electronic pianos of the type utilizing percussively actuated reeds as the tone generators.

An assembly known as an action mechanism is conventionally employed in stringed pianos for transmitting actuating force from each key lever to its associated string. Electronic pianos of the type utilizing vibratile reeds instead of strings as the tone generators also incorporate these :action mechanisms for actuating purposes. Ordina-rily, a horizontal or grand piano type of mechanism is used. However, the vibratile reeds of an electronic piano need be struck only a comparatively light blow for actuation; and, therefore, the hammers used in action mechanisms for an electronic piano are fashioned to be small, relatively lightweight elements. Because of their diminutive size and their lightness, the hammers for electronic pianos are incapable of developing any appreciable frictional force upon engaging a relatively stationary member in a glancing fashion. Difficulty in achieving proper backchecking of these hammers has resulted.

Therefore, an important object of the present invention is to provide an improved backchecking arrangement for hammers of the lightweight type.

A more speciiic object of the invention is to provide a backchecking arrangement in which `the hammer and its cooperating fly engage each other in mechanically interlocked relationship after rebound of the hammer.

A more general object of the invention is to provide a new and improved piano operating arrangement.

Another object of the invention is to provide a piano operating arrangement which facilitates separation of the key levers from the assemblage of action mechanisms.

Still another object of the invention is to provide a piano action mechanism which limits the power which is transmitted to the associated vibratile member.

And still another object of the invention is t-o provide a piano action mechanism incorporating a multiple-element hammer.

Yet another object of the invention is to provide a piano action mechanism that is arranged for easy regulation of the backchecking function.

A further object of the invention is to provide a piano action mechanism which is characterized by the production of sharper tones.

A still further object of the invention is to provide a piano action mechanism that is arran-ged for easy regulation of the dwell-time.

And a still further object of the invention is to provide a new and improved coupling arrangement for use in pianos and analogous musical instruments.

And a yet further object of the invention is to provide a novel coupling arrangement for use in connecting a damp er rod to the damper lever in a piano action mechanism.

These and other objects and features of the invention will become more apparent from a consideration of the following disclosure.

In order that the principles of the invention may be readily understood, several piano operating arrangements, but to which the application is not to be restricted, are shown in the accompanying drawings wherein:

FIG. 1 is a central sectional view taken through an electronic piano structure and showing various arrangements constructed in compliance with the present invention;

FIG. 2 is an enlarged, side elevational view taken in ice cross-section and showing the coupling arrangement for connecting the damper rod land damper lever of the action mechanism illustrated in FIG. l;

FIG. 3 is a plan View taken substantially along the line 3 3 of FIG. 2;

FIG. 4 is a central sectional view taken through a stringed piano structure showing a key lever and an action mechanism coupled in compliance with the present invention;

FIG. 5 is an enlarged, side elevational View taken in cross-section and showing the coupling arrangement of FIG. 4;

FIG. 6 is a plan view taken substantially along the line 6-6 of FIG. 5;

FIG. 7 is a fragmentary view similar to the showing of FIG. 1 but illustrating the position of the parts at the moment of backchecking;

FIG. 8 is an enlarged, side elevational view of a modilied action mechanism arranged to incorporate a multipleelement hammer and adjustment means for individually regulating the backchecking action and the dwell time; and

FIG. 9 is a side elevational view of another modified embodiment of the action mechanism of the invention, particularly arranged for ease in regulating the dwell time and the backchecking action.

Referring now in detail to the drawings, specifically to FIG. l, an electronic piano structure indicated ge11- erally Iby the numeral 20 will be seen to include a front plate 22, a key bed 24, a front rail 26, and a balance rail 28, all of which extend across the electronic piano structure 20. 'I'he balance rail 28 is mounted on the key bed 24 to support and fulcrum an :appropriate number of piano key levers, such as natural note key lever 30 and sharp note key lever 32; and in compliance with conventional practice,

balance rail pins

34 and 36 are driven into the balance rail 28 to upstand therefrom for directing the pivoting action of the natural note key lever 30 and the sharp note key lever 32 respectively. Annular felt washers or punchings 38 are disposed encompassing the balance rail pins between the balance rail and the bodies of the corresponding key levers for cushioning the engagement between the key levers and the balance rail. As is well known, the bodies of the individual key levers are perforated with longitudinally extending slots which 'are laterally lined with felt to receive the balance rail pins. Moreover,

front rail pins

40 and 42 are mounted to the front rail 26 in upstanding relationship to guide the movement of the forward ends of the natural note key lever 30 and the sharp note key lever 32 respectively. Annular felt washers or punchings 44 are disposed about the front rail pins 40 fand 42 to cushion the engagement of the key levers and the front rail.

A key cloth or cushion 46 is fasten-ed to the key bed 24 at a position generally underlying the rear end of the piano key levers for resiliently supporting the same; and adjacent the rear end of each piano key lever, there is mounted a capstan screw 48 which is used in transmitting operating force from the corresponding key lever to the interconnected system of links and levers comprising an action mechanism indicated generally by the numeral 50. The capstan screw 48 has a rounded or spherical head 52 and a tool-engageable formation 54 of non-circular section. The head 52 defines an abuttable engagement member acting between the corresponding key lever and the related action mechanism, and the formution 54 facilitates progressive entrance or retraction of the screw 48 from the Vbody of the corresponding key lever for regulating the height which the screw extends above the surface of the key lever and correspondingly the operative relationship between the key lever and the associated action mechanism.

It is important to observe that none of the operating links or levers of the action mechanism 50 are mounted directly on the corresponding key lever, the only connection between the key lever and its action mechanism being established by the abuttable engagement at the capstan screw 48. This arrangement of the electronic piano structure 20 facilitates removal of the key levers, individually or in mass, without disruption of the relationship of the levers and links in the respective action mechanisms. There is a corresponding facility in the removal of the'action mechanisms. As will be recognized, t-his ease of removal of the various assemblies greatly simplilies both repair and regulation.

Advantageously and in compliance with Tan important feature of the invention, a whip stop member 56 is mounted on key bed 24 closely rearwardly of the key levers to arrest dropping movement of the elements of the action mechanism upon removal of the key lever. The whip stop lmember 56 includes a rail 58 that is directly attached to key bed 24 and further includes a vertical plate 60 which is attached to the rail 58 by screws 52. AThe specific functioning of the whip stop member '56 will be described more fully hereinafter relative tothe description of the detailed construction of action mechanism 50'.

Continuing with reference to FIG. 1, a vibratile reed 64 is mounted on a reed bar 66 by means of a cap screw 68 and alock washer 70. The reed bar 66 is mounted in the piano structure 20 at a position spaced above the rear ends of the various key levers, and the reed 64 is cantilevered from the reed bar to be percussively actuated. To producethe desired musical tone, the vibration of reed 64 is converted into electric oscillations which are converted, in turn, into sound byelectronic means. In compliance with well known practices, a pickup member, not shown, is associated with the free end of the cantilevered reed-64 to form with the reed a capacitor which varies in capacity in accordance with the vibration of the reed whereby to convert the mechanical oscillation of the reed into electronio oscillations. Desirably, the reeds 'associated with bass notes and certain of the reeds -associated with middle register notes are provided with a small weight 72 attached to the free end of the reed for lowering the frequency of vibration without making the reed unduly large.

In order to damp the reed 64 selectively, a damper lever 74 is swingably mounted to a damper rail 76 by means of a damper flange 78 and a pivot pin 80. A damper head 82 is affixedto the underside of damper lever 74 overlying lthe reed 64, and the damper head v82 consists primarily of a felt block which may be directed into cushioned engagement with the reed 64. Additionally, 4a felt pad 8'4 is mounted on the damper rail 76 confronting the .damper lever 74 for providing cushioned engagement between these latter parts. A damper hold spring 85 is attached to rail 76 to contact the lever 74 resiliently and to bias the head 82 toward reed 64 thereby.

Advantageous'ly, the damper rail 76 comprises two similar elements which are interconnected in axial alignment and which are pivotally mounted in the electronic piano structure V20 by means of end shafts 86. At approximately the mid-line of the electronic piano structure 20, a damper rail lift arm V88 is connected tothe two portions -of the damper rail 76 by means of wood screws 90 4and flanges 92. The damper rail lift arm 88is swingably connected to a damper connecting rod 94 by means of a pivot 96; and the damper connecting rod 94 is coupled to a pedal rod 98 by means of a fitting 100, the key bed 24 being fashioned with an .aperture 102 to pass the pedal rod 98 to the pedal mechanism of the piano structure.

A guide housing 104 is mounted on the upper surface of the key bed 24 surrounding the d-amper connecting rod 94, housing 104 being apertured with a bore 106 which freely passes the rod 94. In order to bias the rod 94 in a generally upward direction and therefore bias the damper head `82 4into contactwith the reed 64, a

compression spring 108 is disposed about the damper connecting rod 94 between the guide housing 104 and a spring washer 110 that is yaffixed to the rod 94 by ears 112 radially outwardly extruded from the rod or by similar abutments. If desired, a felt pad 114 may-be situated beneath the lower end of the spring 108 in contact with the housing 104. The guide housing 104 is hollowed with a chamber 116 between the bore 106 and the aperture 102 so that a nut 118 may threadedly engage the lower end of damper connecting rod 94 above the fitting 100. The nut 118 defines an adjustable abutment forengaging the roof of chamber 116, nut 118 and the roof of chamber 116 thereby cooperating to define an upstop for the interconnected rods 94 and 98. By varying the position of nut 118 on the damper connecting rod 94, it is possible to adjust the space between the damper lever 74 and the pad 84 whereby to regulate the so-called lost motion and thereby adjust the extent of the damping achieved by means of the damper head 82. lt will -be recognized that lowering of the rod 98 by means of depressing the corresponding pedalv rotates the damper rail lift arm 88 in the direction `indicated by arrow 120. Correspondingly, the damper rail 76 is pivoted about the shafts 86 in the general direction indicated by arrow 122. Continued rotation of the damper rail 76 in this direction eventually brings the pad 84 into contact with the damper lever 74 to lift the damper head 82 out of contact with the reed 64, in eifect raising the damper.

Returning to a consideration of the means for percussively actuating the reed 64, it is to be recalled that a depression of the lforward end of piano key lever 30 is arranged'to cause a striking of the reed 64 through the piano action mechanism 50. The action mechanism 50 is mounted in the electronic piano structure 20 by means including a main rail 124. The action mechanism 50 specifically includes a hammer 126 that is generally horizontally disposed and that is mounted on a pivot to swing in an arc between a hammer support rail 130 and a positionpercussively engaging the vibratile reed 64. This position of the hammer 126 is indicated in broken outline in FIG. 1. The'pivot pin 128 is mounted to the main rail 124 by a butt flange 132 and a wood screw 134. The hammer 126 carries a hammer shank 136 at its end opposite the pivot pin 128, hammer shank 136 supporting a felt pad or hammer head 138 at its free end for actual contact with the reed 64. Desirably, a felt pad or rest 140 is secured to the upper surface of hammer rail 130 for cushionedly contacting the under surface of the hammer.

The action mechanism 50 also includes a whip 142 that is pivotally mounted on main rail 124 by a Whip flange 144 and a pivot pin 146. The whip 142 swings about a pivot which 'is both spaced from and rigidly connected to the pivot 128. The swinging of whip 142 is caused by a corresponding tiltable swinging -of the corresponding key lever, and the underside of the whip 142 is provided with a Vfelt pad 1'48 at a position spaced from the pivot pin 146 and overlying the capstan screw 48. A liy 150 of unitary, wooden construction is mounted on the whip 142 by means of a pivot pin 152, the fly 150 including a laterally extending foot portion 154, portion 154 'underlying the hammer rail 130. When the action mechanism50 is mounted independently of the corresponding key lever in themanner shown, it is advantag'eous to arrange the hammer rail to provide a let-off function as well. Therefore, a capstan screw 156 is arranged to engage the rail 130 in a threaded lfashion at a position generally overlyingl the foot portion 154 of ily 150. Furthermore, and in order to replace the knuckle which is otherwise conventionally provided on the foot portion of a fly member, a felt pad l158 is secured to the upper surface of foot portion 154, and the capstan screw 156 is fashioned with a rounded or spherical head 160 for cooperating with the felted surface of the `foot portion 154. Therounded vsurface of `the head 4160 cooperates with the felt 158 in a rolling `rather than a sliding fashion. Moreover, the capstan screw 156 incorporates a toolengageable formation 162 adjacent the head 160 axially inwardly therefrom. The formation 162 is fashioned with non-round section whereby to permit gripping by a tool for adjusting the penetration of the threaded shank of the capstan screw 156 into the rail 130; and arranging the screw 156 for radial access in adjustment has proved particularly advantageous since the head 160 of the screw is relatively inaccessible because of its relationship with the deflected foot portion 154 of the fly 150. A jack spring 164 of the compression type is desirably arranged to act between the whip 142 and the foot portion 154 in order to bias the foot portion into contact with the head of the capstan screw 156.

Because of the generally horizontal disposition of the hammer 126, special means must be provided for directing and controlling the interaction of the ily 150 andthe hammer; and in compliance with the invention, these means include a felt-lined pocket or recess 166 which is fashioned in the hammer 126 to open generally toward the head 'or tip of the ily 150. The tip of the ily 150 is adapted to operate within the pocket 166 between a planar backcheck surface 168 and a ily tip engaging, dwell surface 170. The advantageous incorporation of the whip stop member 56 in the electronic piano structure 20 prevents the head of the ily 150 from escaping its position in the padded pocket 166 when the corresponding key lever is removed from the piano structure. Specifically, the upright plate 60 of the whip stop member 56 abuts the undersurface Iof whip 142 upon extraction of the piano key lever to preservev the described relationship of the ily and the hammer.

The planar backcheck surface 168 is carried by the hammer 126 in a position facing toward the pivot 128; and in compliance with an important feature of the invention, the backcheck surface 168 is tilted with respect to a plane drawn perpendicular to the longitudinal axis of the hammer when the hammer is in the backchecking position which is indicated in FIG. 7. This inclination or tilting of the backcheck surface situates a lower toe portion 172 of that surface horizontally closer to a vertical line drawn through the pivot 128 than an upper heel portion 174 of the backcheck surface 168. Cooperatively, the ily 150 carries a planar backcheck surface 176 in generally confronting relationship with the hammer backcheck surface 168. The fly backcheck surface 176 is inclined generally with respect to the longitudinal axis of the ily in order to lodge an upper nose portion 178 against the hammer backcheck surface 168 at a position overlying the toe portion 172 when the hammer and the ily are in the backchecking position. The described relationship of the planar hammer backcheck surface 168 and the planar, ily backcheck surface 176 achieves a mechanical catching of the hammer 126 on its rebound from percussively striking the yreed 64. In effect, the nose portion 178 develops a dog action with the toe portion 172 of the hammer backcheck surface so as to lock the ily 150 and the hammer 126 together. This is distinguished from the more conventional, frictional type of catching action. It is desirable to provide felt padding on at least one of the planar backcheck surfaces 168 and 176; and in speciilc compliance with the illustrated embodiment, felt padding is provided on both of these surfaces.

Returning to FIG. l, the damper lever 74 is seen to be connected to the whip 142 for retraction of the damper head 82 independently of the damper rail lift arm 88. Specifically, an endwise reciprocable damper rod or link 180 is swingably mounted to the whip 142 by a pivot pin 182, pin 182 being situated on the side of whip flange 144 which is opposite the key lever abutment pad 148. The damper rod 180 is connected to the damper lever 74 by means of a coupling unit 184, the coupling unit including a screw 186, a key fork member 188 and a grommet 190. With reference to FIGS. 2 and 3, the screw 186 is seen to include a diametrically slotted head 192 that defines a radially enlarged formation on the damper rod 180. Immediately beneath the head 182, the screw 186 incorporates a smooth-walled shank 194. The grommet 190 is fabricated from a tough resilient material such -as rubber and is specifically fashioned to be perforated with a hole 196 that is of greater diameter than the shank 194. The smooth-walled character of the shank 194 cooperates with the relatively greater size of the hole fashioned in the grommet 190 to permit the grommet to receive the shank of the screw 186 in a freely slidable fashion. With this arrangement, it is possible to :rotate the damper rail lift arm 88 so as to raise the damper lever 74 without transmitting a concomitant force to the damper rod and thence to the whip 142. Thus, the screw 186 and the grommet serve to decouple the damper rod 180 from the damper lever 74 upon independent :retracting movement of the damper lever under the influence of the pedal which is associated with the damper rail lift arm 88.

The grommet 190 is provided with a circumferential groove 198, and the key fork 188 is a bifurcated member which includes opposed, resiliently spreadable tines 200 and a stern 202 that comprises an element doubled upon itself. The stern 202 is adapted to engage the end of damper lever 74 in a piercing manner for connecting the key fork 188 to the damper lever, and the respective arms of the doubled stem 202 merge respectively into the individual tines 200. The tines 200 extend from the end of the damper lever 74 to grip the grommet 190 at the circumferential groove 198 thereof, whereby to position the grommet rigidly with respect to the damper lever. The grommet 190 also includes an upper surface portion 204 which abutably engages the undersurface of head 192. This abutting engagement between the head of screw 186 and the grommet 190 achieves a retracting rnovement of the damper lever 174 under the direction of relative withdrawing movement of the damper rod 180 upon pivoting of the whip 142 to actuate the hammer 126 into percussive engagement with the reed 64. As will be recognized, the retraction of the damper head 82 that proceeds from this movement of the damper lever frees the reed 64 to vibrate when struck by the head of the hammer. In compliance with a feature of the invention, the key fork 188 is fabricated from a spring wire material for resiliently gripping the grommet 190.

It is recognized that the action mechanism 50 may be adapted for use in a stringed or mechanical type of grand piano. Similarly, the coupling unit 184 may be modified to attach a key lever to the abstract of an upright piano action. Therefore and turning to a consideration of FIGS. 4-6, a stringed piano structure 206 is shown to include a key bed 208 which supports a plate 210. A balance rail 212 is mounted in turn on the plate 210 to receive a generally vertically disposed balance rail pin 214, balance rail pin 214 being employed in fulcruming a key lever 216.

The key lever 216 is associated with an action mechanism 218 that includes a hammer 220, hammer 220` being connected to a butt 222 for pivotal action toward a piano string, not shown. The action mechanism 218 also includes a ily or jack 224 which is mounted on a whip 226 for actuation by an endwise reciprocable abstract or sticker 228. The fly 224 includes a tip or head 230 that engages a padded surface 232 on the hammer butt 222 for levering the hammer 20 into percuSsive engagement with the piano string; and in compliance with the present invention, the key lever 216 is connected to the abstract 228 by a coupling unit 234.

The coupling unit 234 includes a screw 236, a key fork 238 and a grommet 240; and turning to a detailed consideration of FIGS. 5 and 6, the screw 236 is seen to include a diametrically slotted head 242 and a smooth walled shank portion 244 beneath the head 242. However, the screw 236 differs from the screw 186 by the provision of a radially enlarged formation 245 spaced beneath the head 242, the formation 245 specifically comprising a collar of greater diameter than the shank 244. The grommet 240, like the grommet 190, is perforated with an axially extending bore 246. However, the bore 246 differs from the bore 196 in that it takes a diameter closely approximating the diameter of the shank 244 for grippingly engaging the shank. As would be recognized, the comparatively tight t between the grommet and the shank of screw 236 cooperates with the radially enlarged formation 245 to fix the grommet 240 against axial movement relative to the screw 236 in the general direction of abstract 228. Of course, the head 242 opposes movement of the grommet in the opposite direction.

The grommet 240 is fashioned with a circumferential groove 248 which receives the opposed and spreadable tines 250 of the key fork 238, the key fork 238 additionally including -a stemv 252 that piercingly engages the end of key lever 2,16. The key fork 238, like the key fork 188, is advantageously fabricated from a spring wire material, and the grommet 240 is desirably made from a tough, resilient material, preferably an elastomer such as rubber.

While a particular embodiment of the electronic piano structure of the invention has been thus far shown and described, it should be understood, of course, that the invention is not limited thereto since many modifications may be made. Therefore and in order to further the understanding of theinvention, two modified embodiments thereof are illustrated respectively in FIGS. 8 and 9. Since the embodiments of FIGS. 8 and 9 incorporate many elements which are comparable to those found in the embodiment of FIG. l, like numerals are used to designate like parts, the suffix letter a being employed to distinguish those elements associated with the embodiment of FIG. 8 land the suffix letter b being utilized to distinguish those elements associated with the embodiment of FIG. 9.

The embodiment of FIG. 8 is particularly characterized by the provision of a multiple element hammer and by the provision of means for adjusting the position of the backcheck and dwell surfaces in the pocket of the hammer. Specifically, the hammer head 138a and the hammer shank 136a are mounted on a first hammer member 254 that is swingably mountedr to a second hammer member 256 by a hinge 258. The hammer member 256 is recessed to receive the hammer member 254, and the axis of hinge 258 is disposedparallel to and spaced from the pivot 128a by which the hammer member 256 is mounted to the main rail 124a. A leaf spring 260 is affixed to the hammer member 256 yieldably to contact the hammer member 254 for resiliently restraining the hammer member 254 with respect to the hammer member 256. In addition, the hammer member 256 includes an abutment member 262 that extends a plate or shoulder portion beyond the end of hammer member 254 for engaging a hammer stop rail 264. The hammer stop rail 264 is horizontally spaced from the main rail 124a in approximately horizontal alignment with the hammer flange 132a. A felt pad 266 is afiixed to the underside of stop rail 264 for providing a cushioned engagement between the stop rail and the abutment member 262 of hammer member 256.

The multiple element hammer 126a controls the power which is delivered to the reed 64a, protecting the delicate reed and prolonging its life. In operation, the amount of force-which a fly transmits to its hammer depends to a large degree on the force transmitted tothe corresponding key lever by the player of the instrument. The force transmitted bythe hammer to the associated reed varies in a related fashion. However, by the construction shown and described With regard to FIG. 8, the mechanical force transmitted to the hammer is delivered to the stop rail 264; and the hammer element 254 swings in independent, inertial movement into percussive engagement with the reed 64a. This inertial swinging movement of the hammer 254 is resisted by the spring 260, Rthe spring 260` backcheck surface 168a is defined by a felt member; and

in order to render the backcheck surface adjustably positionable, this felt part is mounted on a plate 268, plate 268 being affixed, in turn, to a screw 270 that threadedly engages a cooperatively threaded bore formed in depending a heel 272 of the hammer member 256. Oppositely from the plate 26S, the screw 270 is fashioned with a diametric slot 274 which defines a tool-engageable formation for use in directing the screw 270 into progressive engagement with the heel 272. As will be recognized, it is necessary to lift the hammer member 256 above the hammer support rail 13041 to expose the slot 274 for performing the regulation.

It has been mentioned hereinabove that great power is unnecessary in an action mechanism for an electronic piano; and in order to reduce the power of the piano action yand in order to sharpen the tones which are produced, it is desirable to provide means for adjusting the dwell time, that is, the time during which the tip of the iiy stays in contact with the hammer after the fly has been actuated lby depression of the forward end of the corresponding Vkey lever. j The dwell time period begins upon initiation of depression of the forward end of the key lever and ends at the moment of hammer escapement, that is, the moment at which the hammer rises out of contact with the head or tip of the fiy. Therefore, an end piece 276 of the felt which defines the dwell surface 17011 is attached to a plate or dwell button 278; and plate 278 is connected to a screw 280 that threadedly engages a bore formed in the end of hammer member 256. A diametric slot 282 or other suitable, tool-engageable formation is fashioned on the free end of screw 280, and an appropriately shaped aperture 284 is provided in the main rail 124a to provide access to the slot 282 for use in regulating the position of the felt end piece 276. Advancing or retracting the screw 280 relative to the end of hammer member 256 adjusts the distance along the dwell surface a upon which the tip of y 150a rides prior to escapement. It has been found that proper regulation of the dwell time prevents mufiied tones which arise because of the vibrating reed hitting the head of the hammer due to a slow departure of the hammer after initial percussive engagement with the reed. Keen and rapid departure of the hammer from the reed preventsthe introduction of spuious harmonics into the oscillatory output from the ree The, embodiment of FIG. 9 is characterized by the provision of adjustment means for the backcheck surface 168b and the dwell surface 170b both of which are ac.- cessible from above. More particularly, the felt part which defines the backcheck surface 168b is mounted on a plate 286 which is connected to af screw 288 having a '-diametric slot 290 at its free end. In particular accord with the principles of the embodiment of FIG. 9, the screw 288 is angled through the bodyfof hammer 1261i in the general direction of the hammer head 138b.

With, regard to the` dwell surface 170b, the entire felt piece whichdefines the surface is attachedtoa substantially L-shaped plate 292 that is connected to a screw 294 having a. diametrically slotted free end'296. In specific accord with the principles of the embodiment of FIG. 9, the screw 294 passes through the end of hammer 126'b in a generally downward `direction whereby to expose the slot 296V to access from above. Such-mounting" of the screw 294 avoids the necessity for aperturing the main rail 124b.

The manner in which the present invention may be practiced and the purposes to which it may be put are evident from the foregoing descriptions. In addition, the specific examples herein shown and described are to be considered as being primarily illustrative. Various changes beyond those exemplified will, no doubt, occur to those skilled in the art; and such changes are to be understood as forming a part of this invention insofar as they fall within the spirit and scope of the appended claims.

The invention is claimed as follows:

1. In a piano arrangement, the combination comprising: a stationary rail adapted to yact as a rest for a hammer; a vibratile member spaced from said hammer rail; a hammer mounted on a first pivot to swing in an larc between said rail and a position percussively engaging said vibratile member; a whip mounted to swing about a second pivot spaced from said first pivot; a fiy mounted on said whip to swing about a third pivot spaced Ifrom said first and second pivots; a planar backcheck surface carried by said hammer in a position facing toward said first pivot, said surface being tilted with respect to a plane drawn perpendicular to the longitudinal axis of sai-d hammer to dispose a lower toe portion of said surface horizontally closer to a vertical line drawn through said first pivot than an upper heel portion of said surface when said hammer is in backchecking position; and a planar backcheck surface carried by said fly in generally confronting relationship with the hammer backcheck surface, said fly backcheck surface being inclined with respect to the longitudinal axis of said fly to lodge an upper nose portion of said fly backcheck surface against the hammer backcheck surface at a position overlying the toe portion thereof when said hammer and said fiy are in backchecking position whereby to lock said hammer against movement toward said vibratile member.

2. In a piano arrangement, the combination comprising: a stationary rail .adapted to act as a rest for a hammer; a vibratile member spaced from said hammer rail; a hammer mounted on a first pivot to swing in an arc between said rail and a position percussively engaging said vibratile member; a whip mounted to swing about a second pivot spaced from said first pivot; a fiy mounted on said whip to swing about a third pivot spaced `from said first and second pivots; a planar backcheck surface carried by said hammer in a position facing toward said first pivot, said surface being tilted with respect to 'a plane drawn perpendicular to the longitudinal axis of said hammer to dispose a lower toe portion of said surface horizontally closer to a vertical li-ne drawn through said first pivot than an upper heel portion of said surface when said hammer is in backchecking position; a planar backcheck surface carried by said y in generally confronting relationship with the hammer backcheck surface, said fly backcheck surface being inclined with respect to the longitudinal yaxis of said fiy to lodge an upper nose portion of said fly backcheck surface against the hammer backcheck surface at a position overlying the toe portion thereof when said hammer and said fly are in backchecking position whereby to lock said hammer against movement toward said vibratile member; and felt padding on at least one of said backcheck surfaces.

3. In a piano arrangement, the combination comprising: a stationary rail adapted to act as a rest for a hammer; a vibratile member spaced from said hammer rail; a hammer mounted on a first pivot to swing in an arc between said rail and a position percussively engaging said vibratile member; a whip mounted to swing about 'a second pivot spaced from said first pivot; a fly mounted on said whip to swing about a third pivot spaced from said first and second pivots, said fly including a laterally extending foot portion; a planar backcheck surface carried by said hammer in a position facing toward said first pivot,

said surface being tilted with respect to a plane drawn perpendicular to the longitudinal axis of said hammer to dispose a lower toe portion of said surface horizontally closer to a vertical line `drawn through said first pivot then an upper heel portion of said surface when said hammer is in backchecking position; a planar backcheck surface carried by said fly in generally confronting relationship with the hammer backcheck surface, said fiy backcheck surface being inclined with respect to the longitudinal axis of said fly to lodge an upper nose portion of said iiy backcheck surface against the hammer backcheck surface at a position overlying said toe portion thereof when said hammer and said fiy are in backchecking position whereby to lock said hammer against movement toward said vibratile member; and a let-off member on said hammer rail including a spherical head confronting the r.foot portion of said fly to define an abutment for causing pivoting of said fly upon engagement of said head by said foot portion.

4. In a piano arrangement, the combination comprising: a stationary rail adapted to act as a rest for a hammer; a vibratile member spaced from said hammer rail; a hammer mounted on a first pivot to swing in an arc between said rail and a position percussively engaging said vibratile member; a whip mounted to swing about a second pivot spaced from said first pivot; -a liy mounted on said whip to swing about a third pivot spaced from said first and second pivots, said fly including a laterally extending foot portion; a planar backcheck surface carried by said hammer in -a position facing toward said first pivot, said surface being tilted with respect to a plane drawn perpendicular to the longitudinal axis of said hammer to dispose a lower toe portion of said surface horizontally closer to a vertical line drawn through said first pivot then an upper heel portion of said surface when said hammer is in backchecking position; a planar backcheck surface carried by said fly in generally confronting relationship with the hammer backcheck surface, said fiy backcheck surface being inclined with respect to the longitudinal axis of said ily to lodge an upper nose portion of said fly backcheck surface against the hammer backcheck surface at a position overlying said toe portion thereof when said hammer and said fly are in backchecking position whereby to lock said hammer 4against movement toward said vibratile member; and a let-off member threadedly engaging said hammer rail, including a spherical head confronting the foot portion of said fiy to define an abutment for causing pivoting of said fiy upon engagement of said head by said lfoot portion and including a tool-engaging formation axially inwardly from said head.

5. In a piano arrangement. the combination comprising: a stationary rail adapted to act as a rest fora h-ammer; a vibratile member spaced from said hammer rail; a generally horizontally disposed hammer mounted on .a first pivot to swing in an arc between said rail and a position percussively engaging said vibratile member; a whip mounted to swing about a second pivot both spaced from said first pivot and rigidly connected thereto; a key lever fulcrumed intermediate its ends and having a formation abuttably engaging said whip -for actuating the same; a fly mounted on said whip to swing about a third pivot spaced yfrom said first and second pivots; la planar backcheck surface carried by said hammer in a position facing toward said first pivot, said surface being tilted with respect to a plane drawn perpendicular to the longitudinal axis of said hammer to dispose a lower toe portion of said surface horizontally closer to a vertical line drawn through said first pivot then an upper heel portion of said surface when said hammer is in backchecking position; and a planar backcheck surface carried by said fly in gener-ally confronting relationship with the hammer backcheck surface, said iiy backcheck surface being inclined with respect to the longitudinal axis of said fiy to lodge an upper nose portion of said fly backcheck surface against the hammer backcheck surface at a position overlying said toe portion thereof upon removal tplane drawn perpendicular to 6. In a piano arrangement, the combination comprising: la stationary rail adapted 'to act as a rest for a hammer; a vibratile member spaced from said hammer rail; -a `generally horizontally disposed hammer mounted on a `first'pivot -to swing in `anarc between said rail and a position percussively engaging sai vibratile member, said hammer having a pocket adapted to receive the tip of a .fly;-a whip mounted to swing `about a second pivot both spaced from said first pivot and rigidly connected thereto;

.a key lever fulcrumed intermediate 1ts ends and having a formation abuttably engaging said whip for `actuating the i same; a y mounted on said whip lto swing about a third -pivot spaced from said first and second pivots; and a stationary stop member fixed in position beneath said whip and vspaced Vclosely therefrom to permit normal operation thereof and to arrest dropping movement of said key lever, whereby to pre.- serve lthe llocation of the tip of said fiy in said pocket.

7. In a piano arrangement, the combination comprising: ka stationary rail adapted to act as a rest for a hammer; a vibratile member spaced from said hammer rail; ya hammer mounted on a first pivot to swing in anarc between said -rail and 'a position percussively engaging said vibratile member; a whip mounted to swing about a second pivot spaced from said first pivot; a fiy mounted on said whip 4to swing about a third pivot spaced from said first and second pivots; a planar backcheck surface carried by said hammer in a position facing towardsaid first pivot, said surface being tilted with re- Vspect to a plane drawn perpendicular to longitudinal axis of said hammer to dispose a lower toe portion of said surface horizontally close to a vertical line drawn through said first pivot then an upper heel portion of said surface when said hammer is in backchecking position; a planar backcheck surface carried by said fly in ygenerally confronting relationship with the hammer backcheck surface, said fly backcheck surface being Yinclined with respect to the longitudinal axis of said fiy to lodge an upper nose portion of said fly backcheck surface vagainst the hammer'backcheck surface at a position overlying said toe portion thereof when said hammer and said fiy are V.in backchecking position whereby to lock lsaid hammer against movement toward said vibratile member; and means adjustably mounting the hammer backcheck surface to said hammer.

l8. In a piano arrangement, the combination comprising: a stationary railV adapted to act as a rest for a hammer; a vibratile member spaced from said hammer rail; a hammer mounted on a -first pivot to swing in Ian arc between said rail and 4-a position percussively engaging said vibratile member; a whip mounted to swing about a second pivot spaced from said first pivot; .a fiy mounted on said whip 4to swing .about a third pivot spaced from said first and second pivots; a planar backcheck surface carried Vby said hammer in a position facing toward said first pivot, said surface being tilted with respect to a longitudinal Iaxis of said hammer to dispose a lower toe portion of said surface horizontally closer ltoa vertical line drawn through said first pivot then an upper heelportion of said surface when said hammer is in lbackchecking position; a yplanar backcheck surface carried by said fly in -generally confront- Ving relationship with the hammer backcheck surface, said 'fly backcheck surface being inclined `with respect to the longitudinal axis of said fly to lodge an upper nose portion of said fiy backcheck surface against the hammer backcheck surface at a position overlying said toe por- -tion thereof .when said hammer and said fiy are in backchecking position whereby to lock said hammer against movement toward said vibratile member; and means adjustably mounting the hammer-backcheck surface to said hammer, including an adjustment member, abackcheck engageable formation on the other end of said member,

and means between said ends for progressively engaging said hammer.

9. In a piano arrangement, the combination comprising: a stationary 'rail adapted to act as a support for a hammer; a vibratile member spaced from said hammer support rail; Va hammer stop rail positioned intermediate said vibratile member and said hammer support rail; and hammer means including a first hammer member mounted on va pivot to swing in an arc between said support rail `and said stop rail, said first hammer member lhaving an abutment formation for engaging said stop rail, said hammer means further including a second hammer member pivotally mounted on said first hammer member for movement therewith, said second hammer member being spaced from said stop rail for independent, inertially swinging movement into percussive engagement with said vibratile member.

10. In a piano arrangement, the combination comprising: a stationary rail adapted to act as .a support for a hammer; a vibratile member spaced from said hammer support rail; a hammer stop rail positioned intermediate said vibratile member andsaid hammer support rail; hammer means Vincluding a first hammer member mounted on a pivot to swing in an arc between said support rail and said stop rail, saidlfirst hammer member having an abutment formation for engaging said stop rail, said hammer means further including asecond hammer member pivotally mounted on said first hammer member for movement therewith, said second hammer member being spaced from said stop rail for independent, inertially swinging movement into percussive engagement with said vibratile member; and biasing means resiliently restraining said second hammer member in position with respect to said first hammer member.

11. -In a piano arrangement, the combination according to claim fixed to said first hammer member and tacting said secondhammer member.

12. VIn a piano arrangement, `the combination comprising: a-stationary rail adapted to '..act as a support for a hammer; a vibratile member spaced from said hammer supporrtrail; a hammer stop rail positioned vintermediate said vibratile member and said hammer support rail; hammer means including a first hammer mounted on-,a pivot to swing in an -arc between said support rail and said stop rail, said first hammer member having an-abutment formation for engaging-said stop rail, said hammer means further including Ia second hammer member pivotally mounted on said first hammer member for movement therewith, said second hammer member being spaced from said stop rail for independent, inertially swinging movement into 4percussive engagement with said vibratile member; and padding means .acting between said stop rail and said first hammer member for cushioning the engagement thereof.

13. In apiano arrangement, the combination comprising: a stationary rail adapted to act `as ay rest for a hammer; a vibratile member spaced from said hammer rail; a hammer mounted on a first pivot to swing in an are betweensaid rail and 'a position percussively engaging said `vibratile member, said hammer -having a pocket adapted to receive the tip of a fiy; a whip mounted to swing about asecond pivot spaced from said first pivot; a y mounted on said whip to swing .about a third Vpivot spaced from said first and said second pivots; fiy tip engaging means disposed in said pocket; and means adjustably mounting said fiy tip engaging` means to said hammer for regulating the dwell time of the tip ofsaid fly upon actuation thereof.

14. In a piano arrangement, the combination comprising: a stationary rail adapted to act as a rest for a hammer; a vibratile member spaced from said hammer rail; a hammer mounted on a first pivot to swing in an arc be- 10 wherein said biasing means is a leaf spring` yieldably con-` tween said rail and a position percussively engaging said vibratile member, said hammer having a pocket adapted to receive the tip of a fly; a whip mounted to swing about a second pivot spaced from said rst pivot; a fly mounted on said whip to swing about a third pivot spaced from said rst and said second pivots; fly tip engaging means disposed in said pocket; vand means adjustably mounting said fly tip engaging means to said hammer for regulating the dwell time of the tip of said fly upon actuation thereof, including a plate, means connected to said plate and progressively engaging said hammer, and a tool-engageable formation on said last mentioned means.

15. In a piano arrangement, the combination comprising: a stationary rail adapted to `act as a rest for a hammer; a vibratile member spaced from said hammer rail; a hammer mounted on a first pivot to swing in an arc between said rail and a position percussively engaging said vibratile member, said hammer having a pocket adapted to receive the tip of a iiy; a whip mounted to swing about a second pivot spaced `from said first pivot; a fly m-ounted on said whip to swing about a third pivot spaced from said rst and said second pivots; ily tip engaging means disposed in said pocket; and means adjustably mounting said fly tip engaging means to said hammer for regulating the dwell time of the tip of said fly upon actuation thereof, including a substantially L-shaped plate, means connected to said plate and .progressively engaging said hammer, a tool-enga-geable formation on said last mentioned means, and resilient padding means on said plate conlfronting the tip of sai-d fly.

16. In a piano arrangement, the combination comprising: a vibratile member; a damper lever mounted on a first pivot to swing in an abbreviated arc toward and away from said vibratile member; a damper head on said lever for contacting said member selectively to damp the vibration thereof; actuating lever means including an endwise reciprocable Idamper rod; and coupling means connecting said damper lever to said damper rod for retracting movement of said damper lever directed by relative endwise withdrawing movement of said da-mper rod and for Idecoupling said rod from said damper lever upon independent retracting movement of said damper lever, including a radially enlarged formation on said damper rod, a smooth walled shank portion on said damper rod extending a substantial distance beneath said formation, a resilient member disposed `generally about a pa-rt of said shank portion with a confronting wall spaced from said shank portion lfor slidably positioning said resilient member on said damper rod, said resilient member having a surface portion abuttably engageable with said formation, and a bifurcated member aixed to said damper lever and extending therefrom intro gripping engagement with said resilient member.

17. In a piano arrangement, the combination comprising: a vibratile member; a damper lever mounted on a rst pivot to swing in an abbreviated arc toward and away from said vibratile member; a damper head on said lever for contacting said member selectively to damp the vibration thereof; actuating lever means including an endwise reciprocable damper rod; and coupling means connecting said damper lever to said damper rod for retracting movement lof said damper lever .directed by relative endwise withdrawing movement of said damper rod and for decoupling said rod from said damper lever upon independent retracting movement of said damper lever, including a radially enlarged formation ion said damper rod, a smooth walled shank underlying said formation, a resilient member perforated with a hole of greater diameter than said shank whereby slidably to receive said shank, said resilient member having a circumferential groove and having a surface portion abuttably engageable with said formation, and a -bifurcated member aiiixed to said damper lever and having opposed, resiliently spreadable tines extending therefrom to grip said resilient member at said groove.

18. In a piano arrangement, the combination according to claim 17 wherein said tines are of spring material.

19. In a piano arrangement, the combination according to claim 16 wherein said resilient member is Ifashioned from an elastomer.

20. A coupling arrangement for use in pianos and analogous musical instruments comprising: a lever fulcrumed intermediate its ends for transmitting motion to a link; an endwise reciprocable link situated adjacent one end of said lever; connecting means extending from said lever into coupling relationship with said link, including opposed and resiliently spreadable tines, said connecting means further including a separate, tough, resilient member gripped by said tines, said member defining a medial aperture extending therethrough for receiving said link; and means on said link for restricting movement of said resilient member axially of said link.

21. A coupling arrangement according to claim 20 wherein said tines are of spring material.

22. A coupling `arrangement according to claim 20 wherein said resilient member is fashioned from an elastomer.

References Cited by the Examiner UNITED STATES PATENTS 2,767,608 10/1956 Miessner 84-236 2,909,093 10/1959 Andersen 84236 3,040,614 6/1962 Behning 84-240 3,076,371 2/1963 Andersen 84-240 3,139,780 7/1964 Andersen et al 84-240 3,139,782 7/1964 Andersen 84-240 RICHARD B. WILKINSON, Primary Examiner. C. M. OVERBEY, Assistant Examiner.

Patent NoD 3, 319, 503

Charles Sc It is hereby certified that error ent requiring correction and that the corrected below.

line 65, for read Column 6, line 35, for "close" Signed and sealed this (SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer May 16, 1967 Corey appears in the above numbered patsaid Letters Patent should read as "20" read n 200 column ll,

closer 28th day of November 1967n EDWARD J. BRENNER Commissioner of Patents

Claims

1. IN A PIANO ARRANGEMENT, THE COMBINATION COMPRISING: A STATIONARY RAIL ADAPTED TO ACT AS A REST FOR A HAMMER; A VIBRATILE MEMBER SPACED FROM SAID HAMMER RAIL; A HAMMER MOUNTED ON A FIRST PIVOT TO SWING IN AN ARC BETWEEN SAID RAIL AND A POSITION PERCUSSIVELY ENGAGING SAID VIBRATILE MEMBER; A WHIP MOUNTED TO SWING ABOUT A SECOND PIVOT SPACED FROM SAID FIRST PIVOT; A FLY MOUNTED ON SAID WHIP TO SWING ABOUT A THIRD PIVOT SPACED FROM SAID FIRST AND SECOND PIVOTS; A PLANAR BACKCHECK SURFACE CARRIED BY SAID HAMMER IN A POSITION FACING TOWARD SAID FIRST PIVOT, SAID SURFACE BEING TILTED WITH RESPECT TO A PLANE DRAWN PERPENDICULAR TO THE LONGITUDINAL AXIS OF SAID HAMMER TO DISPOSE A LOWER TOE PORTION OF SAID SURFACE HORIZONTALLY CLOSER TO A VERTICAL LINE DRAWN THROUGH SAID FIRST PIVOT THAN AN UPPER HEEL PORTION OF SAID SURFACE WHEN SAID HAMMER IS IN BACKCHECKING POSITION; AND A PLANAR BACKCHECK SURFACE CARRIED BY SAID FLY IN GENERALLY CONFRONTING RELATIONSHIP WITH THE HAMMER BACKCHECK SURFACE, SAID FLY BACKCHECK SURFACE BEING INCLINED WITH RESPECT TO THE LONGITUDINAL AXIS OF SAID FLY TO LODGE AN UPPER NOSE PORTION OF SAID FLY BACKCHECK SURFACE AGAINST THE HAMMER BACKCHECK SURFACE AT A POSITION OVERLYING THE TOE PORTION THEREOF WHEN SAID HAMMER AND SAID FLY ARE IN BACKCHECKING POSITION WHEREBY TO LOCK SAID HAMMER AGAINST MOVEMENT TOWARD SAID VIBRATILE MEMBER.