US3032455A - Plastic molding for covering musical instrument keys - Google Patents

Description

May 1, 1962 R. F. FAUsER 3,032,455

PLASTIC MOLDNG FOR COVERING MUSICAL INSTRUMENT KEYS Filed July 5, 1957 2 Sheets-Sheet 1 May 1, 1962 R. F. FAusER 3,032,455

PLASTIC MOLDING FOR COVERING MUSICAL INSTRUMENT KEYS Filed July 5, 1957 2 Sheets-Sheet 2 ATTORNEYS.

Ueiedigaes In the manufacture of keyboafdA for pianosor the like, it is custornary'to utilize Wooden keybodies sawed from a singlefboard of 4Wood', corresponding to theffinished complete keyboard,` covering material ybeing Iapplied to.v the woodatl some Vstage of the Process, i

V ln the ,c ase of the Whitekeys of Vthe well yknown pianotype keyboard arrangement, it'v has been customary to apply the white covering materialtotheexposed tops and fronts lofthe keys prior .to the sawing of the b oard in to individual keys,` so thatthe keycovering v'material is cu t v` to thekey size and shapeconcurrently with the cutting of the board into individualkeys.v On accountY of. .expan, sion' and contractionof the. kyboardwooden blank with varying atmospheric conditions, ithas been lfound iminacf,

ticable to ap ply. the lkeytop coveringmaterial for an entire board in one piece, and therefore keycover blankseach covering only afew keys, such as an octave orless, havebeen applied individually..toftheaboard withtheir precut tail parts carefully aligned by sight between, the parts `of ,thehboard which `will later `become Athe bases for the black keys.; Thf neXt steps in the. process :have been `to applya separate strip of material tothe front of the keyboardblank to c ompl ete the white.. covering, and then to saw the division lines -betweenthe white keys, by s ightand, with extreme care. vOnce the .keys are vsepa,- rated completely further steps haveV been required. to round, or at least smooth, the roughsaw cutv edges. along thelinesof division, depending on the qualityof key tobe. produced. In addition to requiring these-many process workmen, the.y foregoing priorart method has the v ery, important disadvantage of being limited to use of a covering material which ycanbe.sav\ /ed readily,` for example Celluloid. In accordance with the present .invention a key manufacturing, method, and coveringV material .parts lfor. use therein, are provided whereinoctaveand sub-octave key coverblanksmaybe applied rapidly andwith neither great sk illnor unusual care to a prepared keyboardblank. The keycover blanks are shaped to comprise individual keyt-covers pre-formedto,substantially vtheir final shapes.. with Onlythin ywebs and .other readily "removable: spacer. elernents, each ofI which is recessed from all normally exposed surfaces ofthekeys, .tobe cut throughwhenthe keyboardblank is Ysavved in to individual keys. Sincenov normallyfexposededges of the key cover material are sa 1vt /ed through,` Very hard key cover A. rnateria l,such as Plexiglasl (polymerized methyl 1netl 1a crylat e)A may vbe, '.usedwithout producingchipping at exposed edges, and since the parts actually v sawed throi 1gh are speciallyI shapedfto be easilyrcut, the actual amount of chipping is negligible i Practicef Since the normally exposed edges of the individual key .coversarefnlly formed 'in the preparation of the blanks,

these edges may' be, and preferably are, pre-'formedto a desired finished roundness as a characteristic of the key' cover blank so that no finishing ofthe key covers is necessaryy after the keys Shave been separated. LinesY of sever-V ance between'the white keysf are defined .by these pre-v correspondingl interconnecting websof rthe key "cover fb-lank and other locating means `rin accordance with'the" inventionL soft'hat precisoin grooves are provided c'or're-x spending Vexactly to the cut lines between the keys, and itis a further feature ofthe presentinvention thatf`these,` grooves areutilized forguiding thesmvin separating'the keys so that eventhis operation may be' performed in. a

much more rapid and facile manner, as compared to the' aforedescribed prior art Amethod.`

ccor'dingly, major objects of he pre to provide an improvedmethodofmanufature ofeov.

' ered keys forpiano keyboards and .the like, together; key. covering parts for use in aecordancefwithlfthatl method.

Another object ofthe invention is to provideirnproved .key coverblanks having prepared ronnded ed ges atthe1 Aportions thereof which will form exposed keyedgyesY the finished keys whereby all, major rounding landl polis'h-y A ing operations subsequent| to severance o f t he keyboard blank in to vindividual keys are eliminated.

It is' another object of the finvent ion to. provide'v akey; manufacturing. method and key .cover blanksas aforesaidY wherein the key coversmay be of very hard rnaterial. Stillanother object of the inv.l,on is to provide en improved method of keyboard manufacturel whereiny the placingof thekey covering material on thekeyboard baseboardand the4 sawing of the covered board intoy in d ividual keys are accomplished in ,a `rapidand facile;

manlief...

the foregoinggeneral4 discussion,. the following le' t ailedv l description and claim, and-from the drawings, wherein:

alongline Vll-VII of FIG, 2,L on steps,4 whichrequire. great eareby very v highly skilled FIGS., 1 3 are plan views of three. basic types of key, cover blanksfor -use in covering a-cornplete keyboardin. accordance with the present invention;

FIGS. 4-.6 arer front vviews of the key coyerblanks@ shown ,in FIGS, l-.3, respective ly;,

FIG. 6A is a fragmentary side view taken along. line. VIA--VIA of FlG ..6, onan enlarged scale', FIG. 7 is afragrnentary sectional yview taken about \FI,G. 8 is a sectional view taken about along ,line. VlII'- VllI of.FI G. 4;

FIG. 9 is a sectional y.view taken about along- IX-'IX of FIG. 2;

FIG. 1.0 is Va fragmentary sectional viewtakenabout;

along lineX-X of FIG. 2;

and

FIG. 1l is a fragmentary view of a wooden keyboardr blank,. a central portion thereof beingl broken away',

FIG. 1 2 is a view corresponding to FIG. ll with key., cover blanks of FIGS. 1 3 applied to the keyboard blank;

FIG.y 13 is a fragmentary view .illustrative ofga step'in. a method in accordance with the invention Wherebyin- L dividual keys are, cut from the coveredl keyboardblanldv Referring now more. particularly to .thedrawing, the,

" three typesof key coverblanks shown in vFIGSJ, 2 .andI

3 are ,illustrative of all of rthewhite key .coverblanks needed tocovera standardpiano keyboard in accordance.. with -a preferred y.embodiment of the invention. l..The white keys of such a keyboard consist of seven full .oe-

" tavesflanked on Ithe left by the lowest A ar 1d B keys` paredrounded edges, which yarelocated precisely by the Patented May 1, 1 962 sent viin/ ention arev further. enlarged scaledJ the notes C, D, E, F, G, A, B of the standard piano keyboard. Each of these keys is molded or otherwise fabricated with a lfront key cover portion 34 integra-l therewith, and with all corners along the edges of the key cover which will bey exposed on 4the linished key formed to their linished radii, as shown at 35-35 in FIG. l0, at 36-36 in FIG. 7, and at 38 in FIG. 2, and also along the side edges of the front cover portions 34 in the same manner a-s the similar front cover edges 40 of the sub-octave unit shown in FIG. 8.

The individual key covers of the octave unit are interconnected by webs 42, 4a between the adjacent top` and front portions, respectively, and by bridges 46 adjacent the tail ends of the top covers. The widths of the Webs 42, 44 and the lengths of the tail end bridges 46 are so dimensioned that the individual key covers of the octave unit of FIG. 2 occupy precisely the same relative positions as will the corresponding key base portions in the wooden keyboard blank, shown in FIG. l1 and to be described in greater detail hereinafter, and `as will the corresponding keys of `a linished keyboard.

The webs 42, 44 between the key covers are made as thin as practicable and are co-planar with the under surfaces of the covers, so that when the keys are divided by sawing as will lbe described hereinafter, any burr left where 'the web is sawed lthrough is negligible. On the other hand, a burr where lthe tail end bridges are sawed through yis not objectionable since the tail ends of the keys will be covered in an assembled instrument by a partof the piano or other instrument cabinet. Accordingly the tail endA bridges can be very much thicker and stro-nger than the Webs 42 and are of importance in giving the keyv cover octave blank sutiicient strength for convenient handling. i

' 'Vl/here, as preferred, the key cover blanks are molded from plastic material, it has been found that requirements ot moldability dictate that the webs be of a thickness, for example 0.015 inch, which results coincidentally in `suliicient strength that in most cases no tail end bridge is needed between key covers which are contiguous to their tailends and where, accordingly, the intervening web l2 extends to their tail ends, as in the case of the web 42 between the E and F key covers 28, 29. However, if desired, this web may be thickened at its tail end to provide a tail end bridge portion 53 to preclude any possibility of the web splitting during handling of t-heblank. Nevertheless, provision is made to avoid gross chipping of the hard cover material at the ends of the tail bridges, where they will be sawed through. Accordingly these ends are of a minimum width as shown at SIL-50, the mid-portions 52-52 of the bridges being Wider for strength.

As aforesaid, the sub-octave units of FIGS. l andk 3 are provided tot complete the left and right hand ends, respectively, of the usual piano keyboard. It will be noted that the key cover blank of FIG. l is provide-d with individual key covers 54, Se for A and B keys having integral front cover portions 5S, 6d, and being interconnected by a top cover web 62, a front cover web 64 and a tail bridge 66 which in the illustrated embodiment of the invention are identical to the webs 42 and 44 land the tail bridges 46 ofthe octave unit 22 previously described and space the key covers 54, 56 in the saine manner as corresponding parts of the octave unit are spaced. Since the sub-octave unit required at the right hand of the keyb o-ard consists of a single key, the key cover =blank Z4 for this purpose is not provided with the aforedescribed webs and bridges, although it does include an integral front cover portion 68 generally as aforedescribed.

In the manufacture of a complete keyboard in accordance with lthe present invention, a base wooden board such as illustrated `fragmentarily at 7i?, FIG. ll, is provided, pre-formed with chisel cuts '72-72 in position to form the `front ends of the black key bases of the keyboard, suitable adhesive is applied tothe top and front areas of the board to be covered, the several white key cover units or blanks are applied thereto as shown in FIG. l2, and then the covered board is sawed into individual keys as shown in FIG. 13. In the showing of FIGS. 11 and 12 pants are broken away, with portions of the second and seventh and all of the intervening full octaves omitted, the units for these octaves being identical to that for the first octave, 22, and being referred to collectively at 22.

As aforesaid the key covers within the octave and sub-octave units illustrated in FIGS. 2 and l, respectively, are spacially related prior to being sawed apart by means of the webs and tail end bridges aforedescribed. Further, means are provided to relate the individual key cover blanks to each other and to the board for pro-per positioning of them, on the board during the gluing or cementing operation. For this purpose the tail corner portions of each octave blank 22 are provided at their undersides with locating means, in the illustrated embodiment of the invention comprising integral locating pins 74, 76 and the keyboard base blank or board 7) is provided with companion locating means, in this case locator holes 78, Sti positioned to receive the pins 74, 76 when the octave blank is in proper position on the board; similarly the base blank 70 is provided with additional loca-tor holes 78', 8d positioned for receiving the locator pins of each of the additional octave units 22' which will be yapplied to the board. For providing a preferred manufacturing tolerance, the octave unit locator holes 78, 80, 78', 86', and those `for the sub-octave units, referred to hereinafter, are slightly oversize in the frontto-rear direction, having about .005 inch clearance at the 4front and greater clearance at the rear so that the front cover portions 58, dit, 68 will surely seatirmly on the `board 7d front face, preferably with some tension thereagainst, this seating constituting part of the cover locating means. Accordingly the octave units are positioned with respect to the board and to each other in an accurate and positive manner, and any expansion or contraction of the board will be taken up in an equally divided manner among the spaces between the severa-l octave units.

Similarly, means are provided to locate the sub-octave units of FIGS. 1 and 3 accurately with respect to the board and with respect to the intervening octave units. Since the sub-octave units are relatively narrow as cornpared to the full octave units, it is preferred that the lateral locating means for these units be operative at the rear and front ends of the units rather than at their two rear corners. Accordingly each of the sub-octave units is provided with an integral locater pin S2, 84 at the underside of the tail end portion of the top cover part thereof cooperative with locator holes 86, 88, respectively, provided in the base board "7d, and with a locator shoulder or heel 9d, 92 on the upper portion of an edge of a front cover portion thereof et), 63 respectively. As shown, each locator heel 90, 92 is disposed in position to about the edge of the front cover part of theY key cover of the octave unit next to the corresponding subactave unit when the several units are in place on the wooden board 70, thereby positively locating the frontV end of the corresponding sub-Octave unit to combine with the location provided to the pins 82, 84 at the rear end of those units for complete and accurate location thereof. As shown in FIG. 6A for example, the sub-octave unit locator heels are thinner and shorter than the frontk cover portions 60, 68 upon which they are mounted and preferably are generally triangular in cross-sectional shape, with the base of the triangle at the top and the forward faces 94 of the heels inclined forwardly. Accordingly, when the space between the sub-octave unit and the octave unit occupied by such heel is sawed through, the saw Will rst engage only the corner portion 92 so that the saw cut will be started in a small section of the heel and there will be no likelihood that the heel will be torn off in a body and `carry with it an adjacent part of the key cover. Furthermore since the locator heel or shoulder is located at the top portion of the front cover undernea-th the overhanging portion of the top cover part and is recessed throughout, progressively more so toward its lower end, any saw marks will be substantially out of view when the keyboard is in its assembled relation in a piano or other instrument.

The accurate location of the key cover blanks in cemented relation on the base board 70 and the webs within the blanks provide accurately located and definite spaces or grooves between each of the key covers, which are employed in accordance with the method of the invention to direct operation of the saw in a precise manner. Accordingly, as illustrated in FIG. 13, a specially adapted saw 100 is employed to make the cuts between the adjacent edges of the key covers from the front of the keys to the chisel cuts 72 or to the rear of the key covers, as the case may be, the saw having a guide block 102 fixedly connected in alignment with the saw blade 104 and shaped to fit exactly and engage against the sides of these grooves 98 between the key covers. The thickness of the saw blade is such that the cut made thereby is substantially the width of the grooves, and being exactly aligned therewith by the guide block 102, results in the removal of the webs 42, 44 and 62, 64 as well as the locator shoulders 90, 92. In the arrangement shown, the saw is held in fixed position, as indicated at 106, and the keyboard is moved in the direction indicated by the arrow 108 to make the saw cut.

As will be understood by those skilled in the art, it is customary to complete the severance of the covered key block into individual keys by sawing from the rear ends thereof, so that saw cuts will be made in a later operation progressing forwardly along the side edges of the tail ends of the key covers across the ends of the tail end bridges 46, 62. Since these ltail end bridges are relatively thick, a noticeable saw cut burr may be left at these points, but this part of the key cover will be covered by the piano or other instrument cabinetry when in assembled relation therein. A similar situation obtains where a thickened portion 53 is provided in or supplementarily to the web 42 between the E and F key covers.

Preferably, the under surfaces of the tail end bridges 46, 62 are raised with respect to the under surfaces of the key covers, as shown in FIG. so that these tail bridges will not have been glued securely to the base board 70 during the cementing operation and therefore will be cut free by the sawing operation so as to leave the intermediate wood portions free to receive the usual black key covers in a later operation.

It shculd be noted that in addition to providing maximum strength with a minimum thickness, the extension of the webs 42, 44 and 62, 64 substantially throughout the extent of the adjacent cover edges which they join seals those joints against flow of cement upwardly on to the exposed cover faces. Similarly the minimization of the length of the locator shoulders 90, 92 relative to the vertical length of the front cover parts to which they are attached and the location of those shoulders at the upper portion of those front cover parts decreases the likelihood that any substantial amount of cement will be squeezed onto the adjacent front cover portion of the octave unit, particularly in the more noticeable lower part thereof.

It will be appreciated that in accordance with the present invention covered keys may be manufactured wherein the cover material is very hard and not readily sawable without chipping since all parts of the cover sawed through which will be outside the instrument cabinet when the board is installed are recessed from immediate View and are relatively thin and fragile so as not to carry parts of the main cover body with them when sawed away. Furthermore since all exposed edges may be molded to their final contours and are cleared by the saw, all final rounding and polishing operations are eliminated save for such light polishing as may be desired to remove scratches and the like resulting from handling during the manufacturing operation; the customary light sanding of the key side planes for smoothing the wood parts will remove coincidentally the last vestiges of the webs and locator heels.

While only one embodiment of the process of the invention and parts employed therein have been illustrated and described in detail, it will be understood that the invention is not limited thereto but may be otherwise embodied within the spirit of the invention and the scope of the appended claim.

What is claimed is:

A unitary plastic molding for covering a plurality of musical instrument keys of the piano type by application to a keyboard blank member of Wood, said molding comprising a main plate portion for covering the top surfaces of said keys and a depending plate portion at an edge thereof for covering the front surfaces of said keys, said molding having a series of parallel grooves in said main plate surface conformning with the division lines between individual keys, the width of each groove being substantially equal to the normal clearance between individual keys and the lines of joinder between the walls of the grooves and the top and front surfaces of the molding being smoothly rounded, and means projecting laterally from said molding a distance substantially equal to the width of one of said grooves to abut an adjacent molding and thus space the moldings from each other a predetermined distance in applying the same to a keyboard blank member.

References Cited in the tile of this patent UNITED STATES PATENTS 174,002 Pratt Feb. 22, 1876 210,780 Hyatt Dec. 10, 1878 423,075 Newell Mar. 11, 1890 483,378 Fuller Sept. 27,1892 665,989 Bechtold Jan. 15, 1901 1,014,424 Troeger Jan. 9, 1912 1,504,255 MacDonald Aug. 12, 1924 2,584,319 Appel Feb. 5, 1952 2,626,805 Carlton Jan. 27, 1953 FOREIGN PATENTS 161,000 Australia Feb. 8, 1955 249,145 Switzerland Mar. 16, 1948

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