US3381576A - Piano key aligning means - Google Patents

Description

-May 7, 1968 M. E. JOHNSON PIANO KEY ALIGNING MEANS Filed Feb. 24, 1965 N m Qm mm d MW I E a 5 WE W S w m 3 @B m m w W Wu Q mMHW WW O .Q E 1 aw Q g 3 Q 8 S United States Patent Office 3,381,576 Patented May 7, 1968 3,381,576 PIANO KEY ALIGNING MEANS Melvin E. Johnson, P. A. Starck Piano Co., 2150-60 N. Ashland Ave., Chicago, Ill. 60614 Filed Feb. 24, 1965, Ser. No. 434,783 4 Claims. (Cl. 84-439) ABSTRACT OF THE DISCLOSURE Keyboard for a pianofor-te or similar musical instrument in which the keybed is adjustably attached to its onderlying support and the several keys of the keyboard individually cooperate with adjustably movable stops WhlCh can be selectively regulated to accordingly limit the arcuate movement of the finger engaging surfaces at the playing ends of the keys and concurrently place such surfaces in a selected plane for co-planar alignment: the adjust-able attachment of the keybed to its support cooperating with the key adjustment to selectively position the common plane of the finger engaging surfaces relative to the support.

This invention relates generally to pianos and like musical instruments, and more particularly to a new and improved keyboard assembly including novel means to facilitate the regulation and maintenance of a predetermined depth of touch and alignment of the several keys.

The quality of a piano is, to -a great extent,determ1ned by the precision with which it is constructed. regard to the keyboard, best results are achieved by mamtaimng a uniform predetermined depth of touch and coplanar alignment of the finger engaging surfaces of the several keys. It has been the practice in the piano manufacturing art to construct the keyboard as a subassembly, wh ch is subsequently combined as a unit and co-ordinated with other components in assembling the instrument. The keyboard subassembly comprises a generally rectangular keybed and a plurality of elongated keys pivotally mounted on a longitudinally arranged fulcrum portion of the keybed in the manner of levers of the first order. The several keys move reciprocally about the keybed fulcrum through an angle relative to the central plane of the underlying keybed limited by engagement of opposlte ends of the keys with associated front and rear 1ong1- tudinally arranged portions of the keybed; the range of said angular movement defining the depth of touch of each key. The several keys are maintained in a predetermined spaced relationship on the keybed and guided in their independent angular movement about the keybed fulcrum by spaced pins extending generally upward from said keybed into operatively associated spaced recesses formed in each key. The keyboard subassembly is then mounted on a generally horizontal underlying structural support frame of the piano and fastened thereto; after which the inner ends of the several keys are individually interconnected with the action of the instrument. It is only after the keyboard subassembly has been thus assembled in the instrument that the necessary adjustments to the depth of touch and alignment of the keys can be effectively made. It is well known to those familiar with the art, as heretofore practiced, that compensating adjustments are necessarily made between the keybed of the subassembly and the underlying support frame, and between the underside of the several keys and the balance rail of .the keybed acting as a'fulcrum for the individual keys. According to the present practice, the former adjustment is generally made by prying the keybed from the support and inserting shims therebetween at selected locations to properly position and align the bed of the .tween the fulcrum and the keyboard, while the depth of touch of an individual key is changed by altering its relative position on the fulcrum portion of the keybed in a direction generally normal to the central plane of the keybed. In order to change the depth of touch of selected keys each such key must be raised from the keybed and disengaged from its key positioning pins. The depth of touch of each said selected key is then increased by the addition of paper punchings beportion of the key bearing thereon, and decreased by sanding said bearing portion of the key; after which the key is replaced by engaging it on its associated positioning pins. These adjustments are, in .a sense, complementary, for by raising and lowering the keybed relative to the underlying support at selected spaced locations thereon to achieve alignment of the keybed, the finger engaging surfaces of the keys associated with the keybed at the altered locations are disarranged from their coplanar relationship. Conversely, selectively changing the range of angular movement of selected ones of the several keys to achieve a uniform depth of touch will also disarrange the coplanar relationship of the finger engaging surfaces of the several keys. In both instances compensating changes must be made in the compleimentary means of adjustment to align the finger engaging surfaces of the several keys in a coplanar relaship.

This program of adjustment and alignment, of course, can be performed only by a highly skilled craftsman and consumes a substantial number of hours of his time in reaching a satisfactory result.

This invention avoids the costly procedure heretofore employed to adjust the depth of touch and align the several keys of a keyboard by providing facile means to achieve and maintain an optimum depth of touch and alignment of the several keys of a keyboard after assembly in a piano structure. Briefly, this invention comprises an improved keyboard subassembly having novel quick acting micrometric means for accomplishing predetermined changes in the range of angular movement of each key about the fulcrum port-ion of the keybed, and related means for micrometrical'ly raising and lowering selected portions of the key-bed in relation to the underlying support of the piano, said means being manually operably and mutually co-operative to regulate the depth of touch of each key and to align the finger engaging surfaces of the several keys in a coplanar relationship.

It is therefore, an important object of this invention to provide a keyboard having means operable to micrometl'ically regulate the depth of touch of each key in a piano keyboard and to readily align the finger engaging surfaces of the several keys thereof in a coplanar relationship.

It is also an important object of this invention to provide a keyboard having means operable to compensate for divergence in the depth of touch and alignment of the several keys thereof due to the effects of wear and changing atmospheric conditions.

A further object of this'invention is to provide a keyboard having a plurality of manually operable means located at predetermined spaced points on the bed of said keyboard to alter the relationship of the installed bed with the interconnected underlying support of the piano in a direction generally normal to the plane of abutment therebetween.

The above and further objects, features and advantages of this invention will be recognized by those familiar with the art from the embodiment thereof illustrated in the accompanying drawing and hereinafter described.

In the drawings:

FIGURE 1 is a partial frontal perspective view of a piano illustrating the manner in which the keyboard subassembly of this invention is attached to the piano;

FIGURE 2 is an enlarged sectional view of the keyboard subassembly taken substantially along vantage line 22 of FIGURE 1, looking in the direction of the arrows thereon;

FIGURE 3 is an enlarged partial elevational view of the action connected end of the keyboard, as shown in FIGURE 2, illustrating the key stop attached to the key; and

FIGURE 4 is a sectional elevational view taken substantially along line 44 of FIGURE 2 looking inthe direction of the arrows thereon.

Having thus described the present invention, the specific embodiment, presently contemplated as the best mode of carrying out this invention, will now be described to enable any person skilled in the art to make and use the same.

Referring to FIGURE 1 of the drawings, the structure indicated generally by numeral comprises a conventional upright piano back assembly, indicated generally numeral 11; a keyboard supporting member, indicated generally by numeral 12, connected in a generally horizontal position to the piano back, andthe keyboard subassembly of this invention, indicated generally by numeral 13, mounted on support member 12. The improved keyboard assembly 13, as illustrated in FIGURES 1 and 2, comprises an elongated generally planar keybed, indicated generally by numeral 14, a plurality of elongated keys, indicated generally by numeral 15, improved keybed spacing means indicated generally by numeral 16, and novel key positioning means, indicated generally by numeral 17, all of which will be described hereinafter.

Piano back 11 and support member 12 are typical of the type of instrument to which this invention is adapted, but it will be recognized that this invention is not limited to a particular instrument and can be used with any of the known styles of pianos and other musical instruments employing keyboards. Briefly, support member 12 comprises an elongated frame rigidly connected to piano back 11 and provides a generally horizontal seat to which keyboard 13 is fastenably attached.

The construction and mode of operation of improved keyboard 13 is illustrated in FIGURE 2, although it will be understood that this invention is not limited to the particular embodiment which will now be described. Keybed 14 defines an elongated generally planar frame comprising an elongated front rail 21 having an upper surface 22, bottom surface 23 and front side surface 24; a parallel spaced elongated intermediate balance rail 25 having a bearing surface 26, and a parallel spaced elongated rear rail 27 having an upper surface 28, a rear side surface 29 and a bottom surface 30. Rails 21, 25 and 27 are fixedly interconnected by cross-member 31, and bottom portions 23 and 30 of rails 21 and 27 respectively are adapted for attachment to support seat 20. Keys 15 are arranged in a generally transverse spaced relationship along keybed 14, each key comprising an elongated member which is pivotally mounted on bearing portion 26 of balance rail 25 at fulcrum portion 36 of said key in the manner of a lever of the first order. Front portion 37 and rear portion 38 of each key move toward and away from keybed 14 as the key is moved angularly about balance rail 25 with respect to the central plane of keybed 14. It will be recognized by those familiar with the art that the distance which front portion 37 of each key 15 moves toward and away from keybed 14 is known as the depth of touch of the key. The upper and continuous end surface of front portion 37 are covered by a suitable material such as ivory to provide a durable finger engaging surface and decorative end surface 41. Each key 15 is interconnected with the instrument action; indicated generally by numeral 18, by means of grommet 46 attached to rear end 39 of key 15, grommet 46 being connected to sticker 47 of action means 18. When key 15 is so connected to action 18, rear portion 38 is biased toward rear rail 27 and front portion 37, bearing finger engaging surface 40, is disposed away from front rail 21, this being the normal rest position of key 15. During operation of the instrument, finger engaging surface 40 of selected keys 15 are engaged by the fingers of the user and depressed toward front rail 21, rear portion 38 of said depressed key thereby moving away rom keybed 14 and transmitting the users movement to the action 18 of the instrument.

Angular movement of each of the several keys 15 is limited by the engagement of underside 42 of front portion 37 with piano felts 44 mounted on upper surface 22 of front rail 21 and the alternate engagement of underside 43 of rear portion 38 with key positioning means 17 attached at rear rail 27. The generally transverse spaced relationship of the several keys 15 along keybed 14 is maintained by engaging each key on two spaced pins and 51. Pins 50 extend outwardly from surface 22 of front rail 21 into a longitudinally slotted recess 52 in front portion 37 of each key 15 permitting front portion 37 of each key to move axially in relation to pin 50 toward and away from front rail 21, while restraining lateralmovement thereof. Pins 51 extend outwardly from bearing surface 26 of balance rail 25 through pivoting hole 53 at fulcrum portion 36 of keys 15. Hole 53 in each key 15 comprises a round portion 54 at fulcrum portion 36, which provides a sliding fit over pins 51, and a second slotted portion 55 continuing therefrom and extending through key 15. While each key 15 is restrained from movement normal to the axis of pin 51 by engagement of pin 51 in hole 53, said engagement permits angular movement of key 15 with respect to pin 51. Pins 50 and 51 determine the position of each key 15 on keybed 14, but permit angular movement of each key about balance rail 25. Felts 45 at pins 51 provide a pillow for the rocking action of each key 15 on balance rail 25.

As hereinbefore described, when each key 15 is interconnected with action means 18, rear portion 38 is biased to engagement with positioning means 17, this being its rest position. Finger engaging surface 40 of each biased key is thereby disposed in a plane away from keyboard 14. Each key positioning means 17 is operable to modify the rest position disposition, and hence, plane of finger engaging surface 40, of a key 15 associated therewith. Thus, the rest position of a key 15 is incrementally changed when positioning means 17 associated therewith is moved incrementally toward and away from its rear portion 38. The incremental change in the rest position of a key 15 correspondingly modifies the disposition of finger engaging surface 40 thereof toward and away from key-bed 14. -It will further be recognized that the distance which front portion 37 will travel when a key 15 is moved to its alternate, or striking, position on front key felts 44 is determined by the rest position disposition of front portion 37, and hence, finger engaging surface 40, away from keybed 14. Thus, an incremental change in the rest position of each key 15, relative to keybed 14, alters the disposition finger engaging surface 40 away from keybed 14, and concurrently, increases and decreases the distance that finger engaging surface 40 will travel when key 15 is moved to its striking position, this being known as depth of touch.

In the embodiment illustrated by FIGURE 2, key positioning means 17 comprises a continuous bracket rigidly attached to rear surface 29 of rear rail 27 and extending longitudinally therealong over the length of keybed 14. Screw-eyes 61 are threadedly engaged through bracket 60 and extend toward rear portion 38 of each key 15, each screw-eye comprising a looped head portion 62, a threaded shank portion 63, and outward end portion 64. Stop means 65 are fixedly attached to end portion 64 of each screw-eye 61 and extend axially therefrom toward keys 15, each stop means comprising a body portion 66 and cushioned key engaging portion 67 attached thereto. Rotation of threaded screw-eye 61 about its axis in bracket 60 is translated to axial movement of screw-eye61 and stop means 65 toward and away from rear portion 38 of each key 15, there being one stop means for each key 15. This movement of stop means 65 operates to perform the function, hereinbefore described, of a key positioning means 17, whereby a given rotating motion imparted to looped head 62 of screw-eye 61, micrometrically alters the rest position disposition of the finger engaging surface 40 of the key associated therewith away from keybed 14, and concurrently, proportionately increases and decreases the depth of touch of each said key.

While FIGURE 2 illustrates the presently preferred embodiment, FIGURE 3 illustrates. another embodiment which operates to perform the aforesaid function of key positioning means 17. In this embodiment screw-eye 61a is threadedly engaged in rear portion 38 of each of the several keys 15 and extends therethrough toward a platform portion 32 on rear rail 27. Stop means 65a is fixedly attached to the outer end 64a of each screw-eye 61a and comprises a body portion 66a and cushioned key engaging portion 67a attached thereto, said key engaging portion 67a being engaged on platform 32 when key 15 is in its rest position. In this embodiment, axial movement of screw-eye 61a moves stop means 65a toward and away from rear portion 38 while in engagement with platform 32, and performs substantially the same operative function as screw-eye 61 and stop means 65 illustrated in FIGURE 2.

It will be recognized, that by selective operation of key positioning means 17 the depth of touch of the several keys 15 may be regulated to a predetermined distance, and that the plane of the finger engaging surface 40 of the several keys 15 may be aligned to lie in a common plane.

It will further be recognized that the position of keybed 14 on seat 20 affects the plane of finger engaging surface 40 of the several keys 15. Thus, inaccurracies in construction of keybed 14 and seat 20, and irregularity in mounting keybed 14 on seat 20 will result in misalignment of the cooperating portions of keyboard 13. Inasmuch as keybed 14 has a degree of flexibility, misalignment may also occur at portions of keybed 14. In order to align keys 15 of an installed and connected keyboard 13, it is thus necessary to compensate for the compound inaccuracies in manufacturing and assembly of the aforesaid components by aligning keybed 14 on seat 20. While such adjustment are now made by inserting shims at selected locations between keybed 14 and seat 20, this embodiment of my invention contemplates novel keybed spacing means to facilitate alignment of keybed 14, and for disposing selected portions of keybed 14 at and away from seat 20.

Keybed spacing means 16 comprises a plurality of fastening screws 70 and associated jack screws 71, at spaced predetermined locations on keybed 14, there being one jack screw 71 adjacent to each fastening screw 70. Fastening screws 70 and jack screws are arranged through front rail 21, and have their axes substantially normal to bottom surface 23 thereof. Fastening screw 70 extends from bottom surface 23 and is adapted for threaded fastening engagement in the material of which support member 12 of the selected instrument is constructed, said fastening screw 70 not being threadedly engaged in front rail 21. Jack screw 71 is threadedly engaged in front rail 21 and is arranged to extend therefrom, its butt end 72 hearing on seat 20 of support 12. Head portion 73 of fastening screw 70 and head portion 74 of jack screw 71 are identically adapted for engagement and operation by tools commonly used in the art. Associated pairs of said screws 70 and 71 are arranged at a plurality of spaced predetermined locations in front rail 21. In this embodiment, rear rail 21 is fastenably connected to seat 20 without means for adjustment therebetween, although it will be understood that the use of spacing means 16 is not limited to the aforesaid locations.

Keybed 14 and selected portions thereof are positioned at and away from support 20 by operation of selected associated screws and 71. When attached to support 12, keybed 14 is drawn firmly into abutting engagement with seat 20 by securely engaging fastening screws 70 in support 12. Keybed 14 is then spaced away from seat 20 by loosening selected fastening screws 70 in support 12, and thereafter moving jack screw 71 toward seat 20, butt end 72 thereof bearing on seat 20, thus, separating keybed 14 from seat 20 at that location. Fastening screws 70 are then tightened, fixing keybed 14 in its spaced away position on support 20.

It will be recognized that key positioning means 17 and keybed spacing means 16 function in a co-operative manner in a piano keyboard to achieve the necessary regulation of depth of touch of each of the several keys 15 and alignment of finger engaging surfaces 40 thereof in a coplanar relationship. Further, the said regulation and alignment of the keys 15 is quickly accomplished, for both adjusting means are readily accessible and micrometrically movable to produce a predetermined result, and the entire operation of mounting, fastening and aligning the keyboard assembly 13 can be accomplished with a minimum removal of keys 15 from their engagement on keyboard 14. Trim piece 75 is attached to support 12 at the front end of keys 15 to shield and conceal the working parts of the keybed without interference with the operation of the keys.

While the foregoing description of the present invention covers a presently preferred embodiment, it will nevertheless be understood and appreciated by those familiar with the art that changes, modifications and substitution of equivalent functioning elements may be made in the described embodiment without departing from the spirit and scope of this invention. Having thus described my invention.

I claim:

1. In a piano and like musical instruments, the combination of: a keyboard comprising an elongated keybed having a longitudinal fulcrum portion, a plurality of elongated keys, each having a finger engaging surface at one end thereof, each said key being pivotally mounted on said fulcrum portion and arranged thereon for limited arcuate movement relative to said keybed, said finger engaging surface of each key moving toward and away from said keybed during said arcuate movement thereof; stop means adjacent the other end of each said key for limiting the arcuate movement of said finger engaging surface thereon away from said keybed; means operably connecting each said key to action means of said instrument, each key, when so connected, being biased to a position in which the finger engaging surface thereof is disposed away from said keybed; and regulating means individually associated with each said stop means and operable to selectively modify the said biased position of its associated key independently of the remaining said keys, each said regulating means disposing said finger engaging surface of its said associated key in selected planes away from said keybed and concurrently modifying the range of said arcuate movement of said associated key, whereby the finger engaging surfaces of the several keys may be selectively aligned in a coplanar relationship and the arcuate movement of the finger engaging surfaces may be selectively regulated.

2. In a piano and like musical instruments, the combination of: a keyboard comprising an elongated keybed having a longitudinal fulcrum portion, a plurality of elongated keys, each having a finger engaging surface at one end thereof, each said key being pivotally mounted on said fulcrum portion and arranged thereon for limited arcuate movement relative to said keybed, said finger engaging surface of each key moving toward and away from said keybed during said arcuate movement of said key; stop means between each said key and said keybed, said stop means comprising a plurality of spaced bumpers at said keybed, there being two said bumpers operatively associated with each said key, said bumpers being disposed on opposite sides of said fulcrum portion, each bumper being engaged by a respective spaced portion of the key associated therewith, each said key being arcuately movable between alternate positions of engagement With said two oppositely disposed bumpers, said positions respectively disposing said finger engaging surface of each said key toward and away from said keybed; and independent regulating means associated with one said bumper for each said key, and individually operable for limiting the position of said finger engaging surface thereof away from said keybed, said regulating means comprising screw means threadedly engaged with said key-bed and extending therethrough, said screw means having operating means at one spaced end thereof engageable for rotating the same, the other end being attached to an associated said one bumper rotation of each said screw means operating to move said bumper attached thereto toward and away from said spaced portion of said key engageable therewith, whereby said finger engaging surface of the several keys may be individually aligned in a predetermined plane away from said keybed.

3. In a piano and like musical instruments, the combination of: a keyboard comprising an elongated generally planar keybed having a longitudinal fulcrum defining portion, a plurality of keys, each with a finger engaging surface thereon, pivotally mounted on said fulcrum portion of said keybed for independent limited arcuate movement thereabout; means on each said key for operably connecting one end thereof to action means of said instrument, each said key, when so connected, having said one end thereof biased toward said keybed and the opposite end thereof disposed away from said keybed, said opposite end bearing said finger engaging surface; and adjust- 1 8 a s able means independently operable between said one end of each said key and said keybed to selectively limit the biased position of said finger engaging surface of each key in a selected plane away from said keybed, whereby the finger engaging surfaces of the several keys may be aligned in a selected coplanar relationship.

4. Foruse in a piano and like musical instruments, improved key means comprising an elongated member having a finger engaging surface at one end thereof and means at its opposite end for operable connection with action means of the, instrument, means for operably mounting said member in the manner of a lever of the first order on an underlying generally planar keybed, whereby to move said finger engaging surface thereof arcuately between positions toward and away from said keybed; stop means at said opposite end operable to determine the position of said finger engaging surface thereof away from said keybed; and micrometn'cally operable regulating means connecting said stop means to said member to modify said position of said surface thereof away from said keybed and concurrently determine the range of said arcuate movement thereof.

References Cited UNITED STATES PATENTSv 1,246,998 11/1917 Pickard et al 84435 1,383,500 7/1921 Vasey et al. 84-423 2,040,304 5/1936 George 84-434 FOREIGN PATENTS 115,713 5/1918 Great Britain.

RICHARD B. WILKINSON, Primary Examiner.

L. FRANKLIN, Assistant Examiner.

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