US 2850933 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Sept. 9, 1958 ANDERSEN 2,850,933
PIANO ACTION Filed March 24, 1954 2 Sheets-Sheet 1 IN V EN TOR.
r52 dflderwezz BY QZM/ it m 3 Q6 2,850,933 Fatentedseptfi, 1958 the weightof a conventional piano, particularly a, grand piano. 2850.933 It has been proposed heretofore to produce a comparatively small piano by, using impulsively actuated PIANO ACTION 5 vibratory reeds as tone generators, and by electronically D. ig g ga g or onawan a cmsounds. An additional benefit to be derived from such I a piano is that the pianist may use earphones as trans- Appilcatlon Mar-ch24, 1954, Serial No. 418,273 10 ducers, thereby rendering the piano tones clearly-audible to him, while .allowingothers in the vicinity to pursue 1 Clalm' (CL 84-404) their own activities without distraction. Various difficulties have been encounteredin attempting to obtain pure piano tones in this manner, many of which have not This invention, is concernedgenerally; with an elecheretofore been solved successfully. Substantial mechanitronic piano, and more particularly with apiano action cal problems also have been presented. All of the vibratile therefor. reeds are rathersmall, and the treble reeds are extreme- For countless years pianos and similar instruments 1y small. There has not been enough room for the have been constructed with tensioned strings which have dampers 0f COHVeIIEiOHHI: P actions to engage the been vibrated by striking or plucking in order to proreeds Withouteither getting in the way of the hammers duce musical tones. In the specific case of ianoforte or reacting in an unsatisfactory manner. In connection commonly termed pianos, and so named hereinafter, the with the latter, it will be understood that the reed vibrates stringes are by hgmmers. The vgrious strings of with 1coisiderablekinltensityi1 at the location where it i; a piano are or 1 erent. imensions, weig t, and construclmpu 6 r Strut: v a ammer, an engagement 0 tion, and consequently llllavte1 different vibrational char- (ti d y; damper at t p lilnt is Emilie tobcaus?1 the acterlstics glvlng rise. to 't e istinctive piano tones. One amper to ounce away rom t e ree t iere y ac 1evundesirable characteristic is that the diiferent strings ing imperfect damping andtending to change the pitch have different vibrational decay characteristics. If the of the tone generated. strings were allowed to vibrate naturally, the vibrations It is accordingly an je of this inYenfieh teProvide of some, of them would decay in aslittle as-ahalf secall improved aetiell for electronic Planes The pe end, while others would take progressively. longer to utilizing percussively actuated vibratile reeds as tone gendecay, up to as much as thirty seconds. cra er In order to impart substantially uniform decay tim It is a further object of this invention to. provide an to the strings, it long hasbeen common practice to emimproved damper for an electronic piano of the foregoing ploy dampers. The dampersgenerally employ felt pads Character. which are engageable with the strings mechanically to another Object of this invention is to Provide, in damp vibrations thereof. When a not is.p1ayed th an electronic piano utilizing vibratile reeds as tone gendamper corresponding to that note is withdrawn to allow eratOISi damper Which WilI net rebound or change the the string to vibrate as long a the corresponding k i tone of a reed when engaging the back of a reed adjacent h dOWIi- When the key is r leased, the damper re- 40 the area where the reed is impulsed or struck by a hamengilgesthe stringgfi damp the ydibcll'atictilnslthereof. Fburthlter a-th f th b t d d t f th mec amsm gener y is provi e w 10 1s opera le y er 0 l e an a Van ages 0 P the pianists foot to withdraw all of the damper simulent invention will be apparenefrom the following detaneously to allow loud playing and to achieve certain SCIIPUOH When taken ln'eonnectloh Wllh the p yresonance effects. ing drawings wherein:
Conventional piano actions including the dampers thereg- 1 a fragmentary p p f e f a lf y of occupy a considerable amount of space. In particular, of Ylbrettie Teede and e p h g P121110 actions; the dampers and the hammers percussively actuating the 2 1S a Vertleal Seetlohal e 011 an enlarged Scale strings occupy a considerable space longitudinally-of the showing Of the feeds e i strings and operate on the strings at rather widely spaced 33- 3 a PefSPeCth/e VleW of e 0f p and points. The space taken by the actions including the 4 IS a fragmentary Perspeetlve V1eW 0f the hdampers 1 n conventional pianos is of little consequence, aIllSm for rendering all of the dampers lllopel'atlve In as such pianos are necessarily large anyway. The string Order to aehleve resonant efieets and to P y Wlth louder length necessitates that one dimension (the horizontal di- V011lme-. mension in grand pianos, and the vertical dimension in Refefrlng first t0 Flgs- 1 and there y he Seen uprights) be several feet in length, ranging from about framemember 10 of an electronic piano 12. The frame 31 f t In an inexpensive Plano up, p f et fo ahigh member preferably is m the form of an aluminum angle quality piano. The aggregate string tension characteristibar and 15 mounted between a palr Of end I310C148 A cally Will be on the order of 18 tons, and strong frames plurality of pick-ups 16 1s spaced along the front flange are necessary to resist this tension. Cast iron conven- 0f the frame member or bar 10. The pick-ups are gentionally isused for such frames, and conventional pianos erally in the form of rectangular metal blocks havingslots may weigh from a; little1 $00500 polnrs for hinexplen- 13 neiar odnehenct1 tcliieretof ltlhrgughmwhi lclg screwsZll acrie s1ve piano up to a out poun s or a 1g qua 1ty passe an t rea e in o-t e ar e opposite-en s piano. of the pick-ups are provided with slots 22 opening at. the
For many purposes the imposing size of a conventional ends of the pick-ups, and within which the tone generating pianobis diesiralfile due to Ithel psychologicgl efieit creatied reeldls 24 vciibrgtfle. 1 h h tnere y. n at er casest e arge s1ze an weig t are ee ree s comprise meta tongues aving attac ing cided drawbacks. For instance, student practice rooms lugs26 at one end thereof for receiving mounting screws often must 'be uneconomically large, and it may be ex- 23 which are threaded into an insulating reed mounting tremely expensive or impossible to move a conventional piano into an upstairs apartment. Furthermore, the up per floors of some buildings could not safely withstand b ar. 3ll which. is supported beneath and from theframe member 10 by means of spacer supports 32. It will be understood that the dimensions and weight of the reeds 3 vary flom one reed to another to determine their frequency and vibrational modes. The reeds may be provided at their tips with weights for aiding in the determination of the frequency and vibrational modes.
Beneath, and slightly in front of the reeds and pick-ups, there is located a piano keyboard 32 comprising a plurality of keys 34 pivoted on a board 36 in any known or suitable manner, the board being conventionally mounted on the piano case or frame. The inner end of each key is limited in its lowermost position by a felt pad or stop 38, and the top inner end of each key is provided with a capstan screw 40. Directly above the capstan screw there is a felt pad 42 on a whip 44 which is pivotally mounted at 46 on a whip flange 48 which is secured by means such as screw 50 on a main rail 52 extending between the action brackets 54 which are mounted at opposite ends of the keyboard by means such as screws 56 threaded into the end block, and by any other suitable or conventional means. A plurality of hammers 56 corresponding to the reeds 24 is pivotally mounted as shown at 58 on a metal bracket 60 mounted along the top outer edge of the main rail 52. Each hammer comprises a head having a felt striker 62, the head being conventionally mounted on a shank 64. Each hammer further includes a butt 66 on which the pivotal connection 58 is made, and each butt is provided along its lower edge with a leather abutment or wear strip 68 and felt bumper 70. A catcher stem or shank 72 extends rearwardly from the butt and carries a catcher 74 having its outer face covered with a suitable buffer 76 such as leather.
The rest position of the hammers as shown in Figs. 1 and 2 is determined by a hammer rail 78 which is pivotally supported at opposite ends from the action brackets 54 by means of a pair of hammer rail hooks or swings 80. The face of the hammer rail 78 is provided with a felt pad 82 engageable with the hammer shanks 64 for arresting them quietly and without physical shock. Bracket portions 84 extend up beneath the hammer rail 78 and are provided with felt pads 86 for limiting the lowermost position of the hammer rail. Means is provided for raising the hammer rail including an eyelet 88 screwed into the rail and carrying a grommet 90 through which a pin 92 on a push rod 94 extends. The push rod 94 is connected by means of any suitable linkage to a pedal corresponding to the conventional soft pedal on a conventional piano. It will be understood that when the pedal is depressed, the push rod 94 is raised. This pivots the hammer rail 78 and the hammer rail hooks or swings 80 about the pivotal mounting of the latter on action brackets 54 to push the hammers 56 closer to the reeds 24 and thereby to shorten the stroke of the hammer. The shortened stroke causes the hammers to have less inertia when they strike the reeds whereby the reeds are vibrated with lessintensity, and consequently generate tones of lower volume.
Each hammer is actuated by an L-shaped fly or jack 94 pivotally mounted at 96 on a fly flange 98, the fly flange being fixed on the whip 44. A regulating rail button 100 having a felt pad 102 along the bottom thereof is mounted above the heel 104 of each fiy 94. The buttons 100 are mounted by screws 106 threaded through a regulating rail 108 extending between brackets 110 which are screwed into the main rail 52 or otherwise mounted from the action brackets 54. The buttons are suitably mounted on the screws 106, and the screws are conveniently provided at their upper ends with eyelets for ready finger adjustment.
A backcheck 112 is mounted by means of a backcheck wire 114 near the outer end of the whip 44 and is provided with a felt pad 116 engageable with the felt pad 76 on the catcher 74 when the whip is pivoted by the depression of the key 34. The usual bridle tape 118 extends between the butt 66 and a bridle wire 120 on the whip.
It will be understood that when the key 34 is depressed, the capstan screw 40 pivots the whip 44 about the pivot 46 to force the fly 94 up against the butt 66. When the foot 104 of the fly engages the pad of the regulating rail button, the fly is pivoted from beneath the butt 56, and the hammer continues under its own inertia and strikes the reed 24 as indicated along the dashed line 121. Each hammer is returned by a butt spring 122 fixed in the butt and having an end 124 thereof trapped behind a flange 126 on a spring rail 128 mounted on the action brackets 54 by means such as screws 130. Pivoting of the whip 44 raises the backcheck into position for its felt to engage the felt pad 76 of the catcher whereby to arrest the hammer before it returns completely to its rest position against the pad 82 on the hammer rail 78. When the key is released, the whip and backcheck return to their normal positions and the hammer shanks rest against the padded hammer rail.
In order to prevent unwanted resonant effects and to limit decay times, each reed is provided with a damper indicated generally at 132 (Figs. 1, 2, and 3). Each damper comprises a damper lever 134 pivotally mounted on a damper lever flange 136. All of the damper lever flanges 136 are mounted on a damper lever rail 138 extending transversely across the keyboard. Each damper lever 134 has fixed to it a block 140 having a felt pad 142 engageable by a spoon 144 mounted in the tail end of the whip 44. A set screw 146 secures a damper lever rod or wire 148 in a socket in the block 140 for pivotal movement with the lever 134. The damper rod or wire 148 is offset to clear the reed mounting block or rail 30 and has a damper block 150 secured to its upper end by means such as a set screw 151. The damper block 150 carries a spring 152 which is illustrated as being a substantially U-shaped leaf spring, and the end of this spring carries a. damper pad 154 of resilient material which conveniently can be felt. 'When the whip 44 is pivoted by depression of the key 34, the spoon 144 engages the felt pad 142 on the block 140 to pivot the damper lever 134 about its mounting in the bracket 136. This causes the damper pad to be retracted from the corresponding reed 24 so that the same is free to vibrate when struck by the hammer 56. When the key is released, the damper returns to its damping position under the action of a spring 156 which is illustrated as a leaf spring extending between the damper lever block 140 and the damper lever bracket 136, but which could take other forms.
When the damper pad 154 reengages the reed 24, the reed is vibrating. The spring 152 takes up the vibration and rapidly silences the reed, while maintaining the pad 154 in firm engagement with the reed. The spring 152 keeps the pad 154 from bouncing off of the reed 24 which would cause the reed to be imperfectly damped and would tend to raise the pitch of the reed as the vibrations decay. The spring 152 thus will be seen to be of utmost importance.
Mechanism is provided for simultaneously rendering all of the dampers inoperative in order to play at greater volume and to achieve certain resonant effects. This mechanism includes a foot pedal 158 (Fig. 4) to be operated by the pianists right foot. This pedal is fixed on a rock shaft 160 pivotally mounted in any suitable bearings (not shown) on a fixed part of the piano. A lever 162 is fixed on the other end of the rock shaft 160 and has a pivotal connection with a push rod 164. The push rod 164 has a reduced upper end 166 (Figs. 2 and 4) which fits through a grommet 168 in an aperture in a lever 170. The lever 170 is fixed on a damper operating .rod or bar 172. The damper operating bar or rod 172 engagement with the felt pads 142 (Fig. 2) on all of the damper lever blocks 140 whereby to retract the dampers from the reeds. The dampers remain retracted as long as the pedal is depressed, and are returned by their aforementioned springs when the pedal is released.
It will be apparent that I have herein presented an improved piano action having particular applicability to vibrating reed electronic pianos. The damper pad engages each reed on the back thereof substantially opposite to the point where it is struck by the associated hammer, thereby rendering it possible to clamp the reed. Conventional dampers in string pianos are displaced longitudinally of the springs too great a distance from the hammers and therefore could not be used with Vibrating reed electronic pianos. The vibrations of the reed are particularly strong directly opposite where the reed is struck by the hammer, and in particular they are substantially stronger than the vibrations of a piano string where the damper of a conventional piano engages a string. These strong vibrations tend to make the damper rebound from the reed, and rebounding would result in improper damping action and in upping or raising the tone of the reed. The spring 152 causes the damper pad to comply with the vibrations of the reed while damping the same, thereby completely avoiding rebounding of the damper.
The specific structural details herein shown and described will be understood as being by way of illustration only. Various changes in structure are possible and form a part of this invention insofar as they fall within the spirit and scope of the appended claim.
Piano tone producing mechanism comprising a vibratory reed tone generator of substantially flat configuration and having oppositely disposed substantially flat faces, means for mounting one end of said reed with the other end thereof free for vibration, a piano key, a hammer including a butt and a head carried therefrom, means pivotally mounting said butt for movement of said head toward and away from one flat face of said reed, means interconnecting said key and said hammer for pivotally moving said butt upon movement of said key to carry said head into percussive engagement with said one flat face of said reed at a predetermined striking position thereon, a rod-like damper lever, means pivotally mounting said lever at a greater distance from said reed striking position than the pivotal mounting of the hammer and on the same side of the striking position as the hammer pivotal mounting, said damper lever extending throughout a substantial portion of its length parallel to the reed and on the opposite side thereof from the hammer, said damper lever terminating adjacent said striking position, a damper block secured on the end of said damper lever, a damper padengaging the opposite flat face of said reed at said striking position, and a generally U-shaped fiat blade type spring mounting said damper pad from said damper block, said spring having a pair of parallel flat arms both parallel to said reed flat faces and respectively secured to said block and to said pad and having an interconnecting bight, said bight projecting beyond said block and said pad and bulging outwardly beyond at least one of said arms to impart flexibility to said spring, said spring maintaining said damper pad free from rebound and free from lateral wobble against said opposite flat face of said reed at said striking position to damp vibrations of said reed, and means operatively connected to said key and to said damper lever for pivoting said lever upon movement of said key, whereby to retract said damper pad from said opposite flat face of said reed to free said reed for vibration.
References Cited in the file of this patent UNITED STATES PATENTS 293,855 Doyle Feb. 19, 1884 395,543 Caldera Jan. 1, 1889 579,031 Zintzsch Mar. 16, 1897 967,015 Gilmore Aug. 9, 1910 2,456,321 Rhodes Dec. 14, 1948 2,484,745 Rowe Oct. 11, 1949 2,502,861 Linderoth Apr. 4, 1951 FOREIGN PATENTS 142,178 Germany July 4, 1903