US1507423A - Transposition keyboard - Google Patents

Description

Sept. 2,19% 1,507,423

P. M. PIEL wnmsrosi'rzon KEYBOARD Filed 0st. 15. 1920 sheets-shut 1 P. M. P IE L 1 TRANSPOSITION KEYBOARD Filed Oct. 15. 1920 5 Sheets-Sheet. &

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Patented Sept. 2, 1924.

v UNITED STATES PAUL M. PIEL, on NEW YORK, N. Y.

TRANSPOS ITION KEYBOARD.

Application filed October 15, 1920. Serial No. 417,256.

To all 107mm it may concern:

Be it known that 1, PAUL M. Prnn, a citizen of the United States, and a resident of the city of New York, county of Queens, and State of New York, have invented certain new and useful Improvements in Transposition Keyboards, of which the following is a specification.

This invention relates to transposition key-board musical instruments and is herein disclosed as applied to an upright piano. Transposition of any given piece of written music may herewith be effected mechanically within the instrument itself instead of mentally and manually by the player, that is a piece of music may be played in the key in which it is written while producing the corresponding sounds of any other key desired by merely altering the connections within the piano or other instrument. As will be seen later, the connections are such that they are shiftable over a whole octave, thus rendering the instrument adaptable to any key whatsoever.

As herein disclosed, my invention belongs to that class of transposition devices in which the key-board is shiftable as whole in the piano-frame, while the soundinghoard, string frame, and action-frame may remain fixed, thus retaining much standard piano construction. This class of devices, however, would seem as a matter of mechanical necessity, to be most simply constructed with uniform, equal intervals in the series of keys and action units at their point of contact, a requisite heretofore either completely overlook or else obtained only at the price of many disadvantages, such, for example, as unequal or increased weight and friction in the working parts and a corresponding heaviness, unresponsiveness, and want of smoothness in the touch of the keys.

Despite the want of uniformity in the usual spacing of the wippens, due to structural and acoustic requirements, and the same want of equal intervals in the upper ends of abstracts attached to those wippens, I have found that in most upright pianos the reach of the abstracts is suflicient to enable the lower ends of properly designed abstracts to be spaced into a single series at u iform intervals without inclining any abstract at an angle so sharp as to interfere with the efficient Working or'lthe touch.

of the keys, provided that abstract guides, and guide flanges or adjustable brackets on properly placed flange-rails are employed to take up any lateral strains involved in such inclination of the abstracts.

Since any increase in the distance between wippen and key necessarily reduces the requisite obliquity of any abstract connecting a given wippen withan oif-set key. I have often found it advantageous to shape the keys in such a manner as to lower the key capstan screwor other contact point of key and abstract, such lowering of the key capstan having the added advantage of bringing it more nearly on a level with the key-balance-rail and so of causing a more perpendicular motion of the capstan whenever the key is struck. One means by which this may be accomplished is in replacing the usual rear ends of the wooden keys by metal extensions at the bottom of the keys.

By making the abstract of a light metal (aluminum or alumina alloy) and especially of tubing, it has been found possible to retain all the advantages of wood construction, besides facilitating the length regulation for the abstract itself. This length regulation serves the important function of individual adjustment of the action unit apart from any adjustable means within each key for maintaining the uniform level of the various keys upon which the action unit may come to rest.

To prevent injurv of the keys or action during altering of the key, a rail serving as positive depressor of the rear end of the keys and another rail serving simultaneously as elevator of the wippens and abstracts, may, by suitable means, be so combined with the shifting mechanism proper, that 1) no key can be played as long as the key-board occupies an intermediate position between normal key and action-unit alignments, nor 2) can the key-board be moved until keys and action are safely separated, nor can the separating mechanism itself, at any time, be the means of straining or injuring said keys and action. Furthermore, to render control of such lock and shift mechanism accurate and easy, the locking features may be operated by the performers foot through a pedal, while his hands remain free to shift the key-board the required amount by means of a lever, crank, or other handle provided for-that purpose.

)ther features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a sectional front view of the upper part of an upright piano, along the samealongthe line 272 of Figure, 1, bring wing out the fact that the: piano is overstrimg.

Figure dis a detailed section along the; line 33 of Figure 2, showing the key shiftscale which serves to indicate the position of the keys relative to the hammers or strings.

Figure-17' is an enlarged spread perspective viewof an abstract and? its guide. arms, together with their pivot brackets, the abstract being. partly broken away to show its structure.

Figure 8 is an enlarged perspective view of another form of pivot bracket, forming the pivot supports for two abstract guiding arms;

Figure 9 is a perspective view, on a larger scale, of a key extension. I

Figure 10 is av plan. view of a detail lVhena white piano key is depressed", it rocks on its washer-bearing 2 upon the. balance rail 3 tocraise its rear end upwardly to lift its abstract 1. The abstracti, instead of bearing directly upon the body of the key 1, bears upon an extension 5 substitnted=for a part thereof, held by a screw 6; and" a bolt -7 ta the rearendof the key 1, there, being provided a slot 81 in the. body of the. key where the bolt 7 pa-sses, so that its nut 9, bearing upon the washerlO, mayzbemore or less resiliently seated; or supported: The washer 10 may be of heavy lead, adapted to be whittledl down to obtain any desired bal+ ance of, the key, As thekey is depressed the abstract 4 rises and: lifts the. front err-dot a wippen -l-lz, pivoted at I 12; upon the, usual center rail 12 with the result-that the jack 113; actuatesthe usual hammer l tby striking its usual butt and" its usual regulating button 13%; sov that theham-mer 14:. is; moved from the hammersrail? 14%. againstwhich it ncrmallyrests to str ke. its 149?:i-n the usual manner, The; 11: has? pivot by which the abstract is pivoted to the wippe r also provided with a felt bearing 21. The abstract 4: may be very satisfactoFil-ymade of aluminum tubing having an internal, thread at its lower end into which the shank 22 of a cushion headed capstan screw 28 may be adjustably screwed up to a capstan lock-nut 22 by inserting into the openii s 24: on their peripheries a suitable pronged tool. The cushion 23 may be made of inold'ers cloth cut to cylindrical form with the edge of the recess 23" spun down to grip it.

For guiding the abstracts 4 in their vertical movement, each abstract or each abstract which is appreciably inclined obliquely is held upright by an upper pivoted guide arm or link 25 and a lower guide arm or link 26, each guide link 25 having a turned over end 27, adapted to pass through an opening 28 in its abstract to pivot it thereto. To furnish a broad bearing 28 for each link 25 the hollow abstract may have forced into it an aluminum plug 29, which will at the same time serve to thicken the flattened portion at the top for the bearing 21.

To furnish a bearing for the lower links 26 there is fast on each abstract a lug 28 large enough to furnish a felt-lined bearing 30 for its link 26 so that the tone and touch of the piano are properly preserved. The lugs 2'8 may be held to their abstracts in any suitable manner as being bored to slip over the tube and held inv osition by being upset 1 by apunch. Each upper link 25 has an enlarged bearing end hub 31 having fitted. within it a felt bushing 32 by which the link is carried upon a pivot 33, fast in a small racket 34, adjustably mounted uponthe cross-rail 35, which may advantageously be of: L form, if of metal.

The bracket 34 has a turned-over upper end 86v sothat the pivot 38 passes through boththe turnedover end 36 and the body of the bracket 34, with the result that the hub 32 is held against sliding, The bracket 3d has a lower lozenge shaped extension 37 comprising slot 38 through which latter a bolt 39 may pass and enter the cross-rail extending across the instrument in such mannenthat the pivot points- 33" while ad'- justableup and down and sideto side, still lie approximately perpendicularly below the wip-pen pivots 1 2'. Each bracket 34, as more clearly appears in- Figure 1, stands a considera-ble distance to one side of its abstract 4: thus enabling the swinging links 25 to be of considerable length with the result that the thrustof any inclined, abstract-"is practically transverse to its bracket 34 while friction of pivots 27 and 33 is minimized.

The lower swinging links 26 are usually made double or bail-like, so that instead of engaging their respective abstracts by bentover ends, like the end 27, each engages its abstract by a straight section from which spring arms 41, each terminating in a bentover portion 42. The links 26 may be made of piano or preferably of phosphor-bronze wire so bent that their arms curve apart when free but when assembled in the instrument are straight, being sprung in to fit the bearings which are only about 24 inches apart at the ends 42. Each bent-over portion 42 is journaled in a depending bracket 43 which is adjustably mounted by a bolt 44, passing through its elongated slot 45 and holding it to a bottom flange rail 46, there being an anterior flange rail 46 in front of, and a posterior rail 46 behind th abstracts. The brackets 43 are provided with felt journals 47 serving the same purpose as the felt journals 32.

To prevent any tendency of any link 26 to jump out of its bracket 43 even when its key is struck heavily, the outer ends are bent slightly away from the bail portion 40, as shown at 47. The tips of the bearing ends 27 of the links 25 are bent at right angles as at 48.

By inclining some or many of the abstracts, as appears most clearly in Figure 1, I am able to bring the lower ends of all of them to a uniform spacing, no matter how the hammers and other partsof the actions are grouped to conform to the structural or acoustic requirements of the string-frame or action.

The links 25 and 26 appear to operate to the best advantage when they are so arranged that any upward pressure of the keys on the abstracts tends to stretch the links 25 and 26. Thus upper and lower abstract guides will be on opposite sides whenever there is an appreciable inclination of the abstract while a perpendicular abstract may require no upper guide arm. Inasmuch as the arms 25 are set on the rail 35 behind their abstracts, their brackets 34 on which they are pivoted, are slightly twisted above the rail as at 50, with the result that the links pull squarely on their pivot pins 33.

It has been found advantageous to hold the brackets 43 in position upon the rails 46 by passing their bolts 44 through an auxiliary washer rail or bearing member 52. This auxiliary rail 52 takes the place of washers, and tends to hold all the brackets 43 in place but permits any bracket 43 to be sufiiciently loosened to be adjusted upon its slot 45 by loosening its bolt 44. A similar auxiliary rail 52 serves a similar purpose for the brackets 34 on the rail 35. It will be noted '7' that the inclination of many of the abstracts 4 is materially decreased by adopting the key extension 5, in Figure 2 and separately enlarged in Figure 9, since this enables longer abstracts to be used.

Instead of resting directly on the key extensions 5, each abstract capstan screw 23 is adapted to rest on the flat top of a key capstan screw 53 threaded into its key extension 5 and adapted to be locked in any adjusted position by a capstan lock-nut 54 adapted to be screwed down against the extension 5. This adjustability permits these bearing points of the abstracts on the keys to be accurately adjusted and aligned so that proper working of any action-unit by several keys is assured. To permit this adjustment of the capstan screws 53, the felt 126 (see Fig. 2) of the arrester or back rail 61 is split longitudinally to permit the shanks of screws 53 to descend freely.

hen it is desired to shift the keys 1 to the right or the left to change the key in which music will be played at the operation of the piano keys, a handle 58, beneath the key-bed supporting the keys 1, is rotated to move to the right or left a key carriage comprising the balance-rail or member 3, a front tie member or front key-rail 60, and a rear tie member or back-rail 61. N01- mally, the key carriage is held locked by a fixed pin 62 engaging a shaft 63 carrying the handle 58, said pin normally lying in a longitudinal slot or kerf 64 of the shaft 63. Vhen it is desired to shift the key carriage to carry the piano keys 1 to actuate other hammers and so play in another key, the handle 58 may be pulled out, or a spe cial pedal 66 may be depressed by the foot of the musician to unlock the key carriage. hen the pedal 66 is depressed, the arm 67 on which it is mounted, swings about its pivot 68 within the body of the piano to lift the rear end 69 of the arm against the tension of a spring 70, thereby lifting a push rod 71 to carry the shaft 63 forwardly, carrying its shoulder past the pin 62 so the small rear section 77 of the shaft 63 lies opposite the pin 62 with the result that the shaft turns freely and the handle 58, hitherto invisible and out of the way, projects beyond the front edge of the piano where it can easily be manipulated.

The connections for accomplishing th s include a bell-crank 72 pivoted at 7 3 within the body of the instrument and having an upper forked end 74 engaging a pin 75 on a collar 76 loose upon the rear end 77 of the shaft 63. The collar 76 is shoved forwardly at the rising of the push rod 71 and thrusts against a pin 78 fast on the end 77 of the shaft, shoving the shaft for wardly.

The collar 76 is held against turning with the shaft end 77 because it slidably engages a fixed pin or rod 79 mounted in a suitable r the keys 1 and the abstracts 4.

bracket 80 which also serves asa bearing for the shaft 63.

Not only does the depression of the pedal 66 thus shift the shaft 63 to unlock the keys, but it also effects a separation between V For this purpose the upper end of the push rod 71 actuates a bell-crank 81 pivoted on. a stud 82 within the frame of the instrument, thus pushing forwardly a horizontal link 82,

, pivotally attached at 83 to the bell-crank 81 and pivotally attached at'84 to a bellcrank at 85, with the result that the bellcrank 85 rotatesaround its pivot 86 and P carries a universal bar 86 preferably of wood and having a lower felt covered edge 87, down upon the rear ends of the keys. -The bar 86 lies in front of the extensions 5, and behind the usual fall board 88 which is adapted to swing over thekey-board. This bar 86 now holds down the rear ends of the keys 1.

The abstracts 4 are lifted because the swinging of the bell-crank 85 lifts a universal bar 89 extending across the instru mentbeneath the front ends of the wippens 11. The connections for accomplishing this include a link 90 pivoted at 91 upon the bell-crank 85, for which purpose the bellcrank is formed as a plate, the link 90 being also connected by a pivot 91 to a rock arm 92 which is pivoted at 93 upon a projection of the action bracket 94. Thus the rocking of the bell-crank 85 to hold down the keys 1 also lifts all the wippens 11, and thereby lifts their connected abstracts 4, thus enabling the keys 1'to slide freely along the row of abstracts. To permit this swinging of the universal rodor bar 89, each bracket or frame piece 94 is cut away at 95- sufti ciently to enable the universal bar or rod 89 to have the desired swing. Moreover, the cutting away of the bracket at 95 gives space for the swinging of the guide arms 25; There will be, of course, as many links 90 and as many rock arms 92 as are needed to give adequate rigidity to the universal bar 89 which advantageously is built comparatively light. 1 v

When the keys and abstracts have thus been separated, and the key-board unlocked, the handle 58 may lee-rotated to rotate its shaft 63, which now rotates a bevel gear 97, splined thereto by a key 98 sliding in the kerf 6.4 in the shaft 63, The bevel gear 97 is adapted to shift the key carriage, and for this purpose meshes with a smallerbevel gear 100 fast upon a shaft. 101 provided with a thread 102 upon which runs a nut 103', said nut being held fast to the balance rail 3, of the key carriage by a vertical plate 104'- hejldtothe nut and bearing rail by suit able screws. To permit free passage of the plate104 transversely of the instrument as far, as; is needed, there is provided an open space-105 in the key-bed 59 in which the plate slides. The relation of the gears and the pitch of the screw? 102 is preferably such that each full rotation of the handle 58 shift-s each key 1 from beneath the ab stract under which it has been standing to the abstract next to the right or left thereof.

To enable the musician to determine the notes which the keys 1 are set to play, there is provided on one of the keys, advantageously at middle C, an arrow 106 which is adapted to point to one or another of the notations. of the notes onthe rail 10'] above the keys to which the fall-board or cover 88 usually attaches as clearly appears in Figure 6. i i

To keep the gear 9? always in mesh with the gear 100, the bracket 108, fast to the body of the instrument, serves as bearing for both, the shaft 63 and the shaft 101, and is threaded to receive a set screw or key 109 riding in an annular kerf 110 on the hub111 of the: gear wheel 97. In order to guide the key carriage with adequate accuracy upon the frame of the instrument, its front rail 601's provided with a front kerf 112 so that av bracket 113- may project its turned-over horizontal lug 114 into the kerf 112. A similar bracket 115 may overlie the rear end of the rail 61, both the brackets being suitably fastened to the usual key-bed or platform 59 of the frame of the piano. 1 I

It has been found advantageous to place the bearing bracket 108 somewhere nearer the ends than the center of the instrument To give the requisite steadiness to the shaft 101 there is provided at its end a journal bracket 120, which together with hearing 108 acts as stop. for the movements of the nut 108. 1 i

It is found that a device thus constructed may be readily embodied in many of the standard forms of pianos, even though the hammers are divided into groups by the brackets 94 so that the hammers at the ends of the groups are widely separated from the nearest hammers of the adjacent groups. hat modifications nray be necessary or advantageous in the rails 35, 46, etc., do not usually involve: changes in the skeleton or in the spacing of the hammers or the wippen or'connected parts. Besides providing suitablepivo-t and rail support, as well as adequate clearance at 95, the action brackets 94 are each shaped so as te -allow full freedom for such lateral inclination of the abstracts as may be required to obtain the required intervals o-ftheir lower extremities. Furthermore it has been found advantageous to provide the action brackets 94 with upper threaded portions 122 which 'pass through fixed brackets; 128 and may be held rigidly thereto by u per and lower lock nuts 124. This provides adjustability and rigidity for the hammer supports, each bracket128 including a. slotted horizontal arm 123 adj ustably held by bolts 123. As thus constructed the brackets 94 need none of the usual supports from the key-bed 59, thus enabling the top of the key-bed 59 to be perfectly clear to provide for the shifting of the key-board.

It will be observed that the present construction enables the usual key pins 119" and 119 to be utilized at the front ends respectively of the black keys 127 and the keys 1. Moreover, the rear arresting rail 61 with its felt cover 126 shifts with the keys since it constitutes part of the key carriage. It will be observed that the black keys 127 operate in the usual manner with the usual touch, since they shift bodily with the white keys 1 which have more especially been described above, the bearings 128 of the black keys occupying their usual positions in the device of the present invention, as best shown in Figure 6, so that they operate with the usual touch.

The key-board shown herein (see Fig. 1) includes twelve more keys than there are abstracts in the piano, the key-board being adapted to slide sidewise into either of the extensions 129 of the piano casing thus enabling anyone of the plurality of keys composing the octave to operate any abstract, according to the position of the key-board. To provide suitable openings 130 and keep the ends of the key-bed 59 clear to enable the shifting of the key-board the keyboard 59 is carried on brackets 130 lying beneath it and held to the casing sides by suitable screws 130 To prevent the raised rear ends of the keys beyond the bar 86 from being intercepted by the interior of the casing at 131 when the key-board slides, a depressing cam guide 132 extends inward from each extension 129 of the casing, and has an upturned end 133 adapted to overlie any key in line with it so as to depress the key as the sliding key-board slides it outwardly at that point, to any of the dotted line positions of Figure 4. The length of the cams is such that the idle keys are always looked. It will be noted that the extensions 129 need project only a little beyond the usual piano casing wall even when the twelve extra keys are employed. It will be observed that each abstract bears such a relation to its swinging guide arms 25 and 26 that while each'end of it moves almost as the side of a parallelogram, the arrangement insures that the rising of a key at its actuation has no tendency to shift the abstract across it, nor does the upper end of the wippen tend to shift transversely. Furthermore by adjusting the brackets 34 on their flange rails 46 or by altering the height of one or the other of the flange rails 46, the guide arms 26 may be caused to guide these abstracts at the risin of their keys in such a way as to keep the a stracts resting square- 1y on their key contact points. In the drawing, the front flange rail 46 is slightly lower than the rear rail 46 because the abstract capstan screw heads 23 are above the bearings of the keys on the balance rail 3.

While the pivots 33, 12, 20 and 27 approximate a parallelogram as seen from the side, yet the interval separating the pivots 33 and 12 is not necessarily equal to the interval separating pivots 20 and 27 but is capable of special adjustment by virtue of the slot 38 in the bracket 34, in order that the guide arm 25 may accommodate the movement of the abstract resulting from the relative positions of the lower, front and rear guide arm brackets 43. It will be noted from Figure 1 that the upper ends of the abstracts 4 are bent, whenever necessary, so they extend vertically, thus enabling standard wippens to be used to connect with my novel abstracts. A corresponding bend of the abstracts at the bearing 28 brings the bottom abstract capstan screw vertical; the block of the bearing 28 being placed in the hollow of this bend insures that the guide arm 26 keeps the abstract in alignment.

I have found that an abstract 8 inches in length may have an inclination amounting to the offset of its upper or lower end to the extent of 2% inches without noticeably affecting the touch, even to the fingers of a skilled pianist.

It will be observed in Figure 1 that a, special bracket 34 is shown in Figure 8 provided with two pivots at different levels for two arms 25. I have found that such an arrangement sometimes adds to the simplicity of construction as where opposed inclinations of abstracts would result in overlapping of guide arms.

While all the brackets or vertical supports 94 carry part of the load of the actions, the main load is carried by brackets 144 held by suitable screws to the sides 57 of the casing, each bracket 144 comprising a stub shaft 146 upon which the adjacent action bracket 94 rests in the fork 147 of its exten sion 148, the fork 147 being provided with an adjustable set-screw and lock-nut 145*. form the stud 82 described above.

As is intimated above, the black and white keys may be provided with the usual pins 149 and 150 respectively upon the balancerail 3, these pivots being offset from each other to secure an evenness of touch. After the keyboard has been shifted to the desired position by actuating the handle 58, the weight of the wippens 11 on the universal bar 89 together with the spring 70 automatically return the shaft 63, carrying it along the pin 62 to its Figure 2 or looking position, there being provided, for this purpose a pin 151 upon the collar 76. Since a return of the shaft 63 cannot take place One shaft 146 may be extended to 7 r lEU unless each key is centered properly under one or another of the abstracts which it op- I erates, improper operation of the abstracts by the keys is impossible. The handle 58 ii advantageously near one end of the keyboard as clearly shown in Figure at, thus making it unlikely to catch or interfere with the clothing of a pianist seated at'the piano, or other instrument which is being played.

It will be noted that the pin 56 in the shaft 63 acts as a stop against over-projection of the handle 58 by coming in contact;

with the front axle-bearing 57.

For simplicity of disclosure the fibre and felt materials, washers and packings which may be used to dead'en the shaft 63' and other parts, are omitted, since their use for such a purpose is well known to those skilled.

in the art.

Variations may be resorted to within the scope of the invention.

3. In 'a piano, the combination with wooden keys, of metal extensions extending rearwardly from the bottoms of the keys, wippens above the keys, abstracts between the extensions and the wippens, and relatively long swinging guide arms for the ab stracts each pivoted to one side or the other of its abstract.

4:. In apiano, the combination with a plurality of actionunits, of abstracts for operating said action-units, finger-operated keys adapted to bear against and operate said abstracts, an a balance-rail on which said keys turn substantially on a level with the'lower ends of the abstracts.

5. In a piano, the combination with keys and wippens of an aluminum abstract for each .wippen, and a swinging guide journaled in each abstract and so that the dead ening quality of the aluminunimakes a nonreson'ant bearing therein.

6. In a piano having a series of actionunits, including inclined abstracts with a series of keys, pivoting upon a balance rail, a key capstan-screw for each key and a mountingon each key for its screw adaptedto hold its head substantially on the level of said balance rail bearings, each capstanscrew adapted tooperate one abstract.

7. In a piano having a series of key operated action-units and a balance rail upon which the keys are pivoted, the combination of a capstan-screw for each key and a metal extension on the underside of the rear end of each key in which its screw is mounted.

so that the capstan-screw, approximately at the level of the balance rail bearings, moves with approximate perpendicularity.

8. In a piano having a series of key operated action-units, the combination of a metal extension at the rear end of the body of the key, a lead weight for regulating the balance of said key, and a screw holding the weight and extension to the key.

9. In a piano having a series of keys in front, a parallel series of action-units, each action-unit including a striking hammer,

abstracts each connecting with one of said keys, and a pivoted guide arm for each abstract, so supported that its projection upon a horizontal plane lies oblique to the front of thepiano.

10. In a piano having a series of keys, a series of action units, each including pivoted striking hammer abstracts, and a pivoted guide arm for each abstract so supported that its vertical projection upon a horizontal plane lies oblique to, the direction of the hammer pivot of the same action unit, said pivot being vertically projected upon the same horizontal plane.

11. In a piano the combination with a series of keys, of a series of striking hammers and wippens, inclined abstracts between said wippens and keys and means for so guiding said abstracts that they exert substantially only such thrusts upon either wippen or key as normally lie in the planes of their rotation when struck.

.12. In a piano the combination With series of keys in front and sides at right angles to said front, ofa series of actionunits, certain of said action-units being offset from their keys, inclined abstracts to connect said action-units with their offset keys, and guide arms for said inclined abstracts pivotally connected thereto and adapted to guide them to eliminate all lateral or sideward thrust upon either key or action unit.

13. In a piano having a series of keysat its front, an action including a series of wippens and abstracts for connecting said wippens with the rear extremity of said keys, a bail-like guide arm pivoted in the lower end of each said abstract, and a fixed bearing in front of and behindsaid ab stract for each guide arm. 7 I

14. In a piano having a series of keys at its front,'an action including a series of wippens, and abstracts for connecting said wippens with the rear extremity of said keys, a bail-like guide arm for the lower end of each said abstract, such guide arm having a fixed bearing in front of and behind said abstract, and means for adjusting said fixed bearings so that the path of motion of the inferior extremity of the abstracts may be moved and inclined toward and away from the front.

15. In a piano having a series of wippens pivoted in such manner that the prolongation of their pivots constitute a single straight line, a series of keys, inclined abstracts between said wippens and keys, abstract guide arms a pivot for one extremity of each guide arm in its abstract and an adjustable pivot at the other extremity under and approximately in the vertical plane of said line of wippen pivots but ofiset from the particular wippen to which its abstract is connected.

16. In a transposing piano having a fixed series of wippens, a slidable series of keys, and oblique abstracts connecting the same, and guide-arms for said abstracts, each pivoted at one extremity in an abstract and at the other extremity at a fixed point offset from any vertical plane in which the wippen or its key rotates when struck.

17. In a transposing piano having a series of keys and a series of pivoted striking hammers, the combination of abstracts between the keys and hammer, and a guidearm for each abstract pivotally connected thereto and having an axis of rotation across the vertical plane of the axis of rotation of the connected hammer.

18. In a piano having a series of actionunits, a series of keys offset from said actioirunits. and an inclined abstract in each actionunit and adapted to operate it by its key, the combination with said abstract of a cushion-headed screw with a tubular metal shaft threaded to receive said screw in its lower end.

19. In a piano having keys offset from their wippens hollow aluminum metal abstracts flattened and pierced above to provide bearing surface for articulation with wippens and threaded to receive a cushionheaded screw for articulation with the key.

20. In a piano having a series of wippens offset from their keys, the combination with inclined abstracts bent to form horizontal bearings for articulation in wippen or on key. of guide-arms for said abstracts pivoted in each abstract, and pivots for the gnide-arms at other fixed points offset from the abstract so that any tendency of the bent portions to yield will be effectively counteracted by the pull of said guidearms.

21. In a piano having a series of wippens offset from their keys, an inclined hollow metal abstract between each wippen and its key. and of a ductility suitable to permitthe bending of either end for proper articulation with said wippen and key.

22. In a transposing piano having a series of hammers and a series of finger-open ated keys, the combination of a balance rail on which said keys turn, and inclined abstracts for said hammers resting upon said keys at the level of said balance rail.

- 23. In a transposing piano having fixed action-units and a slida'ble keyboard, the combination with a set of finger-operated keys, of means for separately adjusting both each key and its action-unit relatively to each other.

24. In a transposing piano having strings, a fixed series of action-units including wippens, and a slidable series of keys, the combination of an abstract connecting wippen and key and adjustable in the direction of its length with a key contact point adjustable to and from the abstract.

25. In a transposing piano having a series of action-units, a slidable series of keys, and an abstract between each action-unit and key, the combination of an extensible device in said abstract, with an extensible device in the key to contact with the abstract to permit relative adjustment of each contact relative to the other.

26. In a transposing piano having a fixed series of wippens and a slidable series of keys, the combination with an abstract for each wippen comprising an extensible portion hinged to its wippen, of a key having a contact point for operating it, and means for adjusting the contact point of each key relative to the series of keys.

27. In an upright transposing piano having a fixed frame with sides and a fixed action, the combination with front brackets fast to said side at the ends of the piano of a slida'ble keyboard having more keys than the action has action-units, and an open platform upon which it slides above said brackets, with the result that the key board may slide across and beyond said brackets, said brackets extending out beneath the keyboard.

28. In a transposing piano having a frame with sides, a fixed action with a plurality of action-units, and a movable carriage on which the keys are mounted, the combination of a key-bed for said movable carriage extending beyond said sides and upon which it can move beyond said sides, and brackets secured to said sides and extending under the path of the carriage and rigidly supporting said key-bed from beneath.

29. In a transposition piano having a series of keys, a fixed series of action units, the inferior extremity of said units being uniformly spaced and normally in unit for unit alignment with and in contact with the series of keys, a movable carriage for the keys, and having a pedal for simultaneously raising the action-units and de- 1 pressing the rear ends of the keys, the combinationwith said pedal of means for automatically freeing the key-carriage upon-separation of keys and action and maintaining said separation for all intermediate positions of said key carriage between said 1101 mal alignments, and means for 'automa'tig signature to this specification.

PAUL M. Finn

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