US2928307A

US2928307A - Piano action

Info

Publication number: US2928307A
Application number: US418343A
Authority: US
Inventors: Andersen Clifford
Original assignee: Wurlitzer Co
Current assignee: Wurlitzer Co
Priority date: 1954-03-24
Filing date: 1954-03-24
Publication date: 1960-03-15
Anticipated expiration: 1977-03-15

Description

C. ANDERSEN PIANO ACTION March 15, 1960 4 Sheets-Shea Filed March 24,

March 15, 1960 c. ANDERSEN PIANO ACTION 4 Sheets-Sheet 2 Filed March 24, 1954 March 15, 1960 c. ANDERSEN 2,923,307

PIANO ACTION Filed March 24, 1954 4 Sheets-Sheet 3 IN V EN TOR.

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Q'M/W C. ANDERSEN PIANO ACTION March 15, 1960 mm MW a 4 Sheets-Sheet 4 INVENTOR. (Ye/15 mm? fizderoerz flfimw Filed March 24, 1954 on the order of 18 tons.

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United States PIANO ACTION .Clilford Andersen, De Kalb, IlL, assignor to The Rudoiph Wurlitzer Company, North Tonawanda, N.Y., a corporation of Ohio Application March 24, 1954, Serial No. 418,343

4 Claims. (Cl. 84-237) This invention is concerned generally. with key actuated percussive instruments, and more particularly with a :piano action.

Instruments of thepiano family such as the various forms of the pianoforte, the harp, and the clavichord or detuning with time due to stretching of the strings, loosening-of the mechanism holding the strings, corrosion of the strings which changes their physical dimensions,'temperature variations of the strings and in the supporting and associated structure, variations in moisture content of wood members associated with the strings, and other factors.

Large physical size and great weight heretofore has been associated with pianos. Pianos generally have a plurality of strings for each note, and it is not unusual to find on the order of 200 strings in a piano. The tension on each string may typically be about 160 pounds, and the total string tension of a piano thus may run on In order to withstand this terrific force, piano frames are commonly made of cast iron or other strong and massive material. A grand piano is apt to exceed 1,500 pounds in weight and is apt to be up to nine feet in length to accommodate the long bass strings. Even in upright and small grand pianos the weight may be expected to be at least 500 pounds and the dimension atnt Q of the piano in the direction of the strings may be ex- Various efforts have been made heretofore to reduce the size and weight of pianos by utilizing sound generators other than tensioned strings, or by changing the dimen- These efforts have generally been sions of the strings.

It has been found that a vibratile reed struck by a hammer or the like can be utilized with a proper pick-up as an electrostatic generator for electrical oscillations which when suitably electronically amplified and transduced produces piano-like sounds. Ihave found that by suitablyshaping and dimensioning vibrating reeds and pick-ups piano tones can be produced emulating the fundamentals and harmonics including the build-up and .decay thereof to such a close extent that the piano tones "ice their respective activities unhampered by the tones of the piano.

Suitable mechanism is incorporated in conventional pianos for damping the vibrations of the strings when a key is released by the pianist. Suitable mechanism also may be provided responsive to a pedal for rendering'the damping mechanism inoperative at the will of the pianist in order to achieve certain desired effects. Additionai mechanism is likewise generally provided responsive to another pedal for causing the notes to play more softly. Conventional piano actions are complicated, they are expensive to manufacture, and they require considerable room in the piano. The large space required by conventional actions makes them generally unsatisfactory for use with reed tone generators. More particularly, the small size of a reed, particularly a treble reed, makes it impossible for the hammer and damper of a conventional piano action both to engage the reed. Furthermore, although the use of reed tone generators allows an electronic piano to be produced at a lower cost than in equivalent conventional piano, the expense of conven tional piano actions would keep the price of my electronic piano unduly high.

It is accordingly an object of the present invention to provide animproved piano action, particularly in an electronic piano using vibratile reeds as tone generators.

A further object of this invention is to provide improved damping mechanism in a piano action.

It is a more specific object of this invention to provide, in a piano action, a damper engageable with the edge or side of a vibratile reed whereby the damper and a hammer may engage the reed in a small space.

A further object of this invention is to provide, in an electronic piano tone damping mechanism, an improved means for selectively rendering the same inoperative in order to produce loud or sustained notes.

Yet another object of this invention is to provide, in a piano action, improved means for playing the musical tones at a lower volume.

Other and further objects of the present invention will be apparent from the following description when taken in connection with the accompanying drawings wherein:

Fig. l is a fragmentary perspective view of a corner of a piano constructed in accordance with the principles of my invention and showing portions of the keyboard, actions, and tone generators;

Fig. 2 is a cross-sectional view of the same on an enlarged scale as taken along the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional view taken substan tially along the line 3-3 of Fig. 2 and illustrating the construction and operation of the dampers;

Fig. 4 is similar to a portion of Fig. 2 and illustrates a modification incorporating a mechanism for selectively rendering the dampers inoperative and a mechanism for selectively diminishing the volume of the musical tones; Fig. 5 is a fragmentary perspective view illustrating the damper disabling mechanism and the loud peda for operating the same;

Fig. 6 is a fragmentary perspective view illustrating the volume diminishing mechanism and its connection to the soft pedal; i

Fig. 7 is a top view of the reed mounting structure; Fig. 8 is a front edge view thereof; Fig. 9 is a cross-sectional view of a portion thereof taken substantially along the line 99 through the bass reed area; I Fig. 10 is a view similar to Fig. 9 and taken substantially along the line Iii-10 through the middle freed area;

Fig. 11 is a view similar to Figs. 9 and-IOand-taksn 'bar or member 36.

3 substantially along the line 11-11 through the treble reed area;

Fig. 12 is a perspective view of the bass reed;

Fig. 13 is a perspective view of an intermediate reed;

Fig. 14 is a perspective view of a treble reed; and

Fig. 15 is an exploded fragmentary perspective view illustrating the cooperation of the reeds and associated pick-up.

Referring first to Figs. 1 and 2, there .may be seen the case of a piano 22 constructed in accordance with the principles of this invention. The case 20 is shown only fragmentarily, and it will be understood that this case is on the order of the size of a small spinet piano or smaller. In fact, the case can be of the size of the top portion of the conventional spinet piano and can be placed on a table top or other suitable support for operation.

The piano is provided with a keyboard 24 comprised of white keys 26 for playing the whole notes and black keys 28 for playing the half tones according to conventional practice, the keyboard to all intents and purposes being indistinguishable from a conventional piano keyboard.

The case 20 is provided with a top transverse member or support bar 30 shown in Figs. 1, 2 and 7. The

support bar 3b is made of metal for establishing electrical contact with the tone generating reeds and may be mounted on the end members of the case 20, or may be formed integral with the metal frame fitting within the case. A plurality of tone generating reeds 32 is "spaced along the bar 39, and the reeds are held in place by screws 34 passing through the reeds and threaded into thebar. Each reed is different in size or configuration from every other reed in order to generate the full gamut of piano notes. Typical examples of the reeds will be discussed shortly.

Opposite the support bar 30 and relatively near the front of the keys 2% there is provided a pick-up support The pick-up or support bar or member 36 may be seen in Figs. 1, 2, 7 and 8-11. In Fig. 7 it will be noted that the pick-up support bar 36 is arranged at a shallow angle relative to the reed support bar 30 in accordance with the constant diminishing of the reeds 32 progressing from the bass to the treble end of the instrument. A plurality of pick-ups 38 each cooperable with a plurality of the reeds 32 is secured on the under side of the pick-up support bar 36. The pick-up 38 cooperable with the bass reeds is relatively thick, the pick-up cooperable with the intermediate reeds is somewhat thinner and the pick-up cooperable with the treble reeds is still thinner. The thickness is determined in accordance with the amplitude or magnitude of reed swing, and it will be apparent that the bass reeds necessarily are the largest and have the lar est amplitude of vibration. The pick-ups 33 are insulated from; the pickup support bar 36 by a strip of insulation 40 extending substantially the length of the bar 36.

Each pick-up 38 is provided with a plurality of openings 42, three for example, which receive insulating rub- .ber grommets 44 through which screws or bolts 46 are passed. The screws 48 are threaded into tapped aperplace. The pick-up support bar 36 and associated structure including part of the pick-ups is surrounded by a shielding metallic channel 50 which is lined with felt 52 or the like to insulate the support bar 36 and the associated structure from the channel 50 and to absorb any audible sound.

.As previously noted, the reeds vary in configuration. In Fig. 12 there is shown a bass reed identified as 3212. The reed is provided at one end with an attachment preferably comprising a tab 54b provided with a hole 56b for receiving one of the mounting screws 46. Alternatively, a spade lug could be used, but the construction shown is preferred as it is stronger mechanically and anchors the reed more positively. The reed 32b will be seen to be relatively long and wide, and to have a relatively large, integral weight 5812 depending from its outer or free end. The weight helps to determine the proper mode of vibration of the reed, including the frequency and the buildup and decay. The bass pickup 38 is provided with a plurality of slots (Figs. 7, 9 and 15) within which the ends of the bass reeds 32b vibrate. In Fig. 15 the reeds are shown retracted somewhat from their normal position in order more clearly to illustrate the slots 60. It will be noted that the bass pick-up 38 is stepped at 62 adjacent the forward edge thereof, and that the pick-up is shaped adjacent the step. The shaping of the pick-up and the particular configuration of the reeds combine to produce an electrical oscillation substantially indistinguishable from the sound wave of the corresponding piano note.

In Fig. 13 it may be seen that the intermediate or middle reeds 32 are similar to the bass reeds 3211, but are smaller in length and width, and have smaller weights 58m, the weights in this case being upwardly directed. The reeds 32m are provided with tabs 54ml defining holes 56m for receiving the mounting screws. The intermediate pick-up 38 as illustrated in Fig. 10 is shaped somewhat differently than the bass pick-up. However, the configurations of the pick-ups are generally similar and the intermediate pick-ups are generally similar and the intermediate pick-up includes slots 66 in which the reeds 32m vibrate.

Reference to Fig. 14 illustrates that the treble reeds 32! are generally similar to the bass and middle reeds, but are smaller in length and width, and have smaller downwardly directed integral weights 58:. The treble reeds are provided with mounting tabs 54: defining holes 56! for receipt of the mounting screws or bolts. Fig. 11 illustrates that the treble pick-up 38 is similar to the bass and middle pick-ups, but is substantially thinner. The treble pick-up is provided with slots 60 for the reeds 321 to vibrate in.

The means for playing the various musical tones is illustrated in Fig. 2. The keys as illustrated by one of the keys 26 are conventionally pivoted on a block62 mounted on a frame member 64 by means of the usual pins 66 and felt pads 68. A front key pin 70 is provided according to the usual practice properly guiding the movement of the key, and a felt stop 72 is provided adjacent this pin.

A fly mounting member 74 is mounted on the top of the key inwardly of the pivot by means of a pair of screws 76 and a cylinder 78. The fly mounting member may be rotatably adjusted about the cylinder "/8 by threading one of the screws in and the other one out. A substantially L-shaped fly or jack 80 is pivoted on the ily mount 74 as at 82. A spring 84 is compressed between the tail of the fly and the body of the key 26.

Fixed flanges 86 (Figs. 2 and 3) are mounted at opposite ends of the piano case by any suitable means. A

butt rail 88 extends transversely across the piano and a plurality of butt flanges 90 is mounted thereon in spaced relation by means such as screws 92. A plurality of braces 93 is spaced along the butt rail 86 to prevent bowing or flexing of this rail, which it will be understood is made of wood. The supports 93 extend down to the bed of the keyboard or to any convenient rigid frame member. There is one butt flange 90 for each key and reed as readily will be understood, and the butt 94 of a hammer 96 having a shaft or shank 98 is pivotally connected to each but flange as at 180. Each hammer 96 is provided with a felt pad striker 102 on the head thereof and aligned for engagement with a corresponding reed 32 when the hammer and butt are pivoted about the pivot on the butt rail.

Ahammer rail 104 extends across the piano between the brackets 86 and ispadded at the top by afeltpad 105 against which the shanks 98 of the hammers 96 gravitationally rest to determine their quiescent position. The hammer rail 104 is made of Wood according to conventional practice, and a plurality of stops or regulating buttons 106 having felt padded faces 108 is mounted on screws 110 threaded through the hammer rail 104. The screws 110 preferably are provided with eyelets 112 for conveniencev of adjustment. The regulating button 106 is positioned so that the felt face thereof will be engaged with the tail 114 of the fly or jack 80 when the same is raised by the key. The butt 94 is provided with a wear strip 116 of more or less conventional construction against which the upper end of the long arm 118 of the fly or jack butts for raising the hammer. The butt also is provided with a wall or stop 120 engageable with the long arm 118 of the fly or jack to keep the samefrom moving rearwardly too far under the impetus of the spring 84. When the key is depressed, the jack pushes up against the butt to start the hammer upwardly. When the tail of the jack engages the regulating button, the jack pivots from beneath the butt and the hammer continuous to rise due to inertia until it strikes the reed 32.

A felt pad 122 is placed on a fixed frame part beneath the inner end of each key to limit the rest position of the key. A backcheck wire 124 extends upwardly from substantially the innermost end of each key 26 and is provided at its upper end with a leather backcheck 126 which is raised by depression of the key into position to catch the heel 128 of the hammer as the hammer rebounds from the reed and thereby noiselessly to stop motion of the hammer without rebound at a position slightly above its normal rest position. The hammer, of course, returns to its normal position when the key is released.

A plurality of damper rods 130 (Fig. 2 and 3) is pivotally mounted along the hammer rail 104. Each of the damper rods is provided with a laterally extending apertured car 132 which may be welded or otherwise secured to the rod. A screw 134 passes through each rod and is screwed into the hammer rail 104.

Each damper rod 130 is straight through most of its length and is offset near the upper end thereof as at 136, the upper end being provided with a felt pad 138 engageable with the side or edge of a corresponding reed to damp the same. Each rod also is oifset in the same direction near its lower end as at 140, and the lower end is beveled at 142. The beveled end 142 is engageable with a felt cover 144 on a tilted damper actuator 146 mounted on the corresponding key 26 near the inner end thereof. A spring 148 encircles each screw 134 and has one arm thereof looped around the damper rod 130 as at 150, the other end being bent over the top of the hammer rail 104 as at 152. In addition to actuating the hammer as aforenoted, depression of a key acts through the damper actuator 146 and beveled end 142 of the damper rod to pivot the damper rod about its mounting screw 134 and thereby to withdraw thefelt damper pad 138 from the associated reed 32. This condition is illustrated with respect to the second key from the right in Fig. 3, this being one of the half tone keys 28. In this figure it will be seen that the felt damper pad on the damper rod has been moved to the side where it is entirely clear of the hammer. In Fig. 2 the path of a striking hammer has been indicated by a dot-dash line, and it will be noted that the hammer and damper act on the reed very close to one another. This affords a superior damping action and allows the hammer and damper to act with facility on small reeds. It will be understood since the damper is moved entirely to the side of the hammer, that in the case of the very smallest reeds the hammer and damper can act on the reeds substantially at the same point, rather than spaced longitudinally of the reed as illustrated in Fig. 2.

The piano action heretofore described is a basic mechanism. No provision is made for loud playing, i.e. rendering the dampers temporarily ineffective, or for soft playing. A modification of the piano action equipped for loud and soft playing is shown in Figs. 4-6. This action generally is identical with the action heretofore disclosed with the addition of extra parts. In order to avoid prolixity, I have labeled the identical parts with the same identical numbers, and the structure and operation of these parts will he understood as being identical with those previously disclosed.

The mechanism for rendering the dampers temporarily inoperative in order to play at higher volume and to achieve certain resonant efiects is shown in Figs. 4 and 5.

.A comb 154 in the form of a fiat plate is slidably mounted in suitable slots 156 in the end members of the piano case or frame. The comb is provided with a plurality of alternate teeth 158 and slots 160*. One tooth is positioned between each adjacent pair of damper rods 130 with the dmnper rods fitting in the slots 160. A pair of coil springs 162 is mounted in suitable bores in the piano frame or case and bear against the left end of the comb as illustrated in Fig. 5 to bias the comb to the right. The extreme rightmost position of the comb may be limited by abutment of the right end of the comb against the inner extremity of the slot 156, or against any suitable stop. In this normal spring biased position the left edges of the teeth are not quite in engagement with the damper rods 130, and the damper pads 138 are held against the edges of the reeds by the damper springs 14-8.. The slots are sufiiciently wide that the damper rods can be pivoted as heretobefore disclosed when a key is depressed.

The piano is provided with the usual loud pedal 164 which is mounted on a pivotal rod 166 which is suitably journaled in a fixed part of the piano. A lever 168'is fixed on the other end of the rod and'is pivotally connected at 170 to a pull rod 172. The upper end of the pull rod 172 is pivotally connected at 174 to one end of a bell crank 176. The bell crank is pivotally mounted at its apex on a bracket 178 fixed on the end wall of the piano frame or case. The extremity of the other arm of the bell crank is received in a slot 180 along the back of the comb. When it is desired to render the dampers inoperative for loud playing or for creating resonant effects as is done in conventional piano playing, the pedal 164 is lowered by the pianists foot. This pivots the rod 166 and lever 168 to lower the pull rod 172. This, in turn, pivots the bell crank 176 and shifts the comb 154 to the left against the action of the springs 162. The direction of motion of all of the parts when the pedal is depressed is illustrated by arrows in Fig. 5. Movement of the comb 154 to the left brings the left edges. of all of the comb teeth 158 into engagement with the damper rods and pivots the damper rods away from the reeds. When the pedal is released, the springs 162 return all of the parts to their normal positions, and the damper springs pivot the damper rods back into damping position. It will .be noted that the upper arm of the bell crankcould be allowed to abut the supporting wall to limit movement of the comb to the right, and in this case the right end of the comb would not have to abut a stop.

A soft pedal 182 (Fig.6) also is provided on the piano and is fixed on a rod 184 pivotally mounted in suitable bearings on fixed parts of the piano. It will he noted that the rod 184 is somewhat longer than the rod 186 so that the soft pedal can be mounted to the left of the loud pedal as is the custom in conventional pianos. The push rod 186 has its lower end pivotally connected at 188 to a lever 190 fixed on the opposite end of the rod 184 from the pedal 182. A grommet 192 best seen in Fig. 4 is held on the upper end of the push rod 186 by a screw 194 and is received in an eyelet 196 mounted on the sof bar 198.

The sof bar 198 is mounted immediately beneath the shanks 98 of the hammers 96 by means of a pair of arms 200 pivotally mounted on the opposite ends of walls of the piano frame or case. The bar 198 is provided along its upper surface with a felt pad 202 for soundproof and shockproof engagement with the hammer 200 and the side walls on which the arms are pivoted. The bar is pivoted on the arms so that the felt padded face thereof will always flatly engage i116 hammer shanks. It will be understood that suitable stops may be provided on the walls for engagement by the arms 200 to limit the lowermost position of bar 198 or this position may be limited by a limit on the position of the pedal 182.

In the quiescent position of the soft bar 198, it is held down by the springs 204 to a position where it just engages, or does not quite engage, the hammer shanks 98 as the hammer shanks rest against the felt pad 105 on the top of the hammer rail 104. When the pianist wishes to play softly, he depresses the soft pedal 182 with his left foot as is conventional with pianos. This pivots the rod 184 and lever 19% and raises the push rod 186 to raise the soft bar 198 to the position shown in Fig. 4. In this position the hammer shanks are supported by the felt pad 202 on the bar 198 and are held above the pad 105 on the hammer rail 1%4. As a result, the stroke of each hammer is reduced. Consequently, the hammers do not build up as much speed and inertia and do not strike the reeds such hard blows. This causes the reeds to sound more softly than when they are struck following a full stroke of a hammer.

It will be apparent from the foregoing description that I have presented herein a new or improved piano action having primarily, but perhaps not exclusive, application in electronic pianos using percussion vibratory reeds for generators. The reeds occupy a minimum space as tone generators, and the reeds are engaged alternatively by the hammers and by the dampers in a relatively restricted zone. The simplification of the piano action also contributes to reduction in size. The novel mechanisms disclosed for playing loud and soft make a further contribution to the diminution in size. Consequently, a piano constructed in accordance with the principles of my invention may be substantially smaller'than a conventional piano. 7

It will be understood that the specific examples herein shown and described are for illustrative purposes. Various changes in structure may be made and form a part of my invention insofar as they come within the spirit and-scope of the appended claims.

I claim:

1. In an electronic piano having a plurality of percussively actuated tone generating vibratile reeds each having a striking surface and only one damping surface along a longitudinal edge displaced substantially 90 therefrom; a plurality of piano actions respectively corresponding to a plurality of said tone generating vibratile reeds, each of said piano actions comprising a piano key, a hammer movably mounted adjacent said key and movable into striking engagement with the striking surface of a corresponding one of said reeds to vibrate that reed,

means interconnecting said key and said hammer for moving said hammer into striking engagement with said reed in response to depression of said key, a damper engageab le with the damping surface along the longitudinal edge of said reed, means mounting said damper for pivoting movementabout an axis substantially parallel to the corresponding reed, and means operatively interconnectedwiththe key and engageable with the damper pivotally to. retract the damper from the reed upon depression of said key; and means for simultaneously retracting all .of said dampers, comprising a comb-like member extending transversely across substantially all of said dampers and having a plurality of lateral projections at least equal in number to said dampers and respectively projecting between said dampers, means supporting said comb-like member for longitudinal movement transversely of said dampers, and means for so moving said comb-like member to engage each damper with one of said projections whereby simultaneously to pivot all of the dampers out of contact with the respective reeds.

2. The combination as set forth in claim 1 wherein the comb-like member is of fiat, intergral one-piece construction with a plurality of slots extending in from one edge and providing the projections.

3. The combination as set forth in claim 1 wherein the dampers and hammers are pivotally mounted on the same side of the reeds, and wherein the dampers are provided with offsets afording clearance for the hammers.

4. The combination as set forth in claim 2 wherein each damper is pivoted intermediate its ends and is provided with an oblique surface on the end opposite the reeds, and wherein each key is provided with a cam member, depression of a key bringing the cam member thereon into engagement with the oblique surface of the corresponding damper to pivot said damper to retracted position.

References Cited in the file of this patent UNITED STATES PATENTS Rs. 8,319 Hanchett July 2, 1878 43,245 Vergnes June 21, 1864 367,073 Steck July 26, 1887 579,031 Zintzsch Mar. 16, 1897 596,906 McPherson Jan. 4, 1898 967,015 Gilmore Aug. 9, 1910 1,353,442 Wessell Sept. 21, 1920 1,929,027 Miessner Oct. 3, 1933 2,456,321 Rhodes -2 Dec. 14, 1948 2,571,298 Scott-Huntington Oct. 16, 1951 2,581,963 Langloys Jan. 8, 1952 2,601,185 Bergh June 17, 1952 FOREIGN PATENTS 142,178 Germany July 4, 1903