US1748777A

US1748777A - Piano

Info

Publication number: US1748777A
Application number: US223743A
Authority: US
Inventors: Bernhard F Laukandt
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-10-03
Filing date: 1927-10-03
Publication date: 1930-02-25
Anticipated expiration: 1947-02-25

Description

Feb. 25, 1930. B.-F. LAUKANDT PIANO Filed Oct. 3. 1927 4 Smeets--Sheec` 1 Y INVENTOR muti/Jada BY 91@ ATTORNEY n l, .itlL/ L l Feb. 25, 1930. B. F. LAUKANDT 1,748,777

PIANO Filed Oct. 5, 1927 4 Sheets-Sheet 2 mm m m ....W .M ./IM W ...W Wm

Feb. 25, 1930. B. F. LAUKANDT 1,748,777

PIANO Filed 0G12. 3, 1927 4 Sheets-Sheet 3 INVENTOR www@ ATTORNEY Feb. 25, 1930. B. F. LAUKANDT PIANO Filed Oct. 3. 1927 4 Sheets-snee?l 4 dn mn AN T@ m7/J n n .llulilull u f4 m o 3 ro ff 4 do 9 2 J Q, J 7% f 700 J f wr/2 h 6 6 F/ f Patented Feb. 25, 1930 PATENT OFFICE BERNHARD F. LAUKANDT, OF RED WING, MINNESOTA PIANO Application filed October 3, 1927. Serial No. 223,743.

rlhis invention relates to improvements in planos generally, and more particularly to a percussion type of action for such forms of stringed musical instruments.

l ture, to obtain a quick repetition of the haA mer strokes with much less fin ger motion than is required by the ordinary standard action, and to reduce the number of parts in action to a minimum without sacrificing any of the vadvantages attached to the old and well known standard actions.

A further object of the invention is to provide for a simple but effective means, whereby the percussion strokes of the hammers of a piano action are automatically shortened or lengthened correspondingly with the actuation of the soft pedal control of the piano, and consequently a greater range in volume and tone is obtained with an ease and precision not heretofore found to be possible in known types and makes of pianos.

Another object of the invention is to provide a means whereby any and all liability of accidental repetition strokes of the hammers of piano actions is positively prevented, without in any way effecting a quick response of the hammers to the action of the reys when being fingered.

A still further object of the invention is to provide for a piano action wherein the construction and arrangement of its parts is such as to permit of a more compact assembly of the same, and to an extent to allow for the housing of the action in casings or cabinets of much smaller dimensions than has heretofore been possible in the practice, which will, as a consequence thereof, result in an appreciable decrease in material and a corresponding decrease in cost of manufacture.

Wththe foregoing and other equally important objects and advantages in view, the invention resides in the certain new and useful combination, construction and arrangement of parts as will be hereinafter more fully described, set forth in the appended claims, and illust-rated in the accompanying drawings in which:

Figure 1 is a fragmentary view in eleva tion, partly in section, showing a practical embodiment of the improved action together with the supporting frame thereof,

Figure 2 is a vertical section taken on the line 22 of Figure 1,

Figure 3 is a fragmentary View, partly in elevation and partly in section, showing the piano action in its position of rest,

Figure 4 is a vertical section taken on the line M of Figure 3,

Figure 5 is another fragmentary view, partly in elevation and partly in section, but showing the action with the hammer disposed in striking position,

Figure G is a horizontal section taken on the line 6 6 of Figure 5,

Figure 7 is another horizontal section taken on the line 7-7 of Figure 5, and

Figure 8 is a similar cross sectional view to that of Figures 3 and 5, but showing the abstract moved to a second position with respect to the hammer butt.

Referring to the drawings, wherein similar characters of reference designate corre spending parts throughout the several views thereof, the preferred embodiment of the invention is illustrated therein in its associated relation with respect to a conventional form of key 10 and a string 11, which key and string are supported in position in a usual manner. The improved piano action is indicated generally at 12, and is mounted on a frame 13, which includes a lower position 14 having a rearwardly disposed vertical portieri 15 and an upper portion 16 having a similarly disposed vertical portion 17. rThe upper end of the lower vertical portion 14- is shouldered, as at 18, while the upper vertical portion 1'? is shouldered, as at 19, at point intermediate its ends. The upper end portion of the upper frame portion 16 is outwardly curved to provide a forwardly extending portion forming a shoulder 20.

The piano action 12 includes a main or supporting rail 21 mounted on horizontally aligned shoulders 18 of the several frame members 13 employed in the piano structure. This main or supporting rail 21 is channellcd or grooved, as at 22, longitudinally of its forward face to slidably support within the same a Hange rail 23. A slotted opening 24 is formed in the main or supporting rail 21 in the plane of the horizontal center of the channel or groove 22 to receive through the same a screw 25, b means of which the flange rail 23 is retaine in position. Engaged beneath the head portion of the screw 25 are a pair of washers 26 of metal, which are preferably spaced apart by means of an interposed washer 27 of a compressible material Such as felt or the like, whereby to cushion the parts in position. The forward face of the flange rail 23 is formed to provide a longitudinally extending ledge or rib 28 on which is seated a flange member 29, one of such flange members being provided for each hammer action unit of a completed piano. This flange member 29 is secured in position by means of a screw 30, passed inwardly through its forward face and engaged in the flange rail. As shown in Figures 1, 3 and 5, the upper and lower walls of the channel or groove 22, in the main rail 21 are preferably faced with felt in a usual manner.

A butt 31 is pivoted. as at 32, to the upper end of the flange member 29, which is of reduced proportions to project into a bifurcation 33 formed inwardly of the lower face of the butt for the purpose substantially as shown in Figure 2. This lower face of the butt 31. forwardly from the point of pivotal connection with the flange 29, is of a stepped formation having an inner inclined face 34 and an outer inclined face 35, which are to be alternately engaged by oppositely disposed inclined or angularly arranged faces 36 and 37 (see Figure 4) formed at the upper end of a key actuated member or abstract 38. The upper end of this member or abstract 38 is of a reduced width between the inclined or angularly disposed end faces aforesaid, and this reduced portion projects upwardly within the slotted bifurcation 33 of the butt- 31. Opening upwardly through the rearwardly disposed portion of the butt 31 substantially in line with the pivot 32 is an upwardly flared recess 39, downwardly through which is extended the lower end of a shank 40 for connection with a pivot 41 extended crossways of the bifurcation 33 in slightly spaced relation above the pivot 32. Mounted on the upper end of the shank 4() is a hammer 42.4 A post 43 having its lower end secured in the upper face of the butt 31 extends upwardly in line with the shank 40 and forwardly thereof, and carries at its Lipper end a head 44 to which is secured a leather strap in the form of a loop 45 arranged in embracing engagement about the shank 40 of the hammer. When the action is in motion. the post 43 serves to drive the hammer or to transmit impulses thereto from the butt 31, and also serves as a back-check therefor. However, when the action is at rest, the post 43 lays against a rest rail 46, which is faced with a block of felt 47 in the usual manner. Also, the striking surfaces of the hammer 42 and the head 44 are faced with blocks of felt 48 and 49 respectively. Mounted within the bifurcation 33 of the butt 31 on a cross pin 50, which is located in a plane midway between the

pivots

32 and 41, and slightly rearwardly thereof, is a coiled spring 51 arranged to have one of its ends to bear against the rear side of the reduced upper end portion of the flange 29, and its other end against the rear side of the lower end of the shank 40. This spring 51 functions to retain the butt 31 and the hammer 42 in their normal forwardly inclined positions, when the action is at rest, and to return the same to such position, after each playing stroke transmitted to the butt 31 through the abstract 38 from the key 10.

Located immediately in rear of the abstract 38 is an upper guide rail 52, and a lower guide rail 53 projecting from the forward faces of which are guide members or

hooks

54 and 55 respectively, the member or hook 54 being arranged to have its forward angularly bent end extending across the forward fa ce of the abstract 38, and the member or hook 55 with its similarly bent end projecting through a vertically elongated guide slot 56 provided in an enlarged portion 57 formed at the lower end of the abstract 38, by which arrangement only a vertical or up and down movement to the latter is permitted. The lower face of the enlarged lower end portion 57 of the abstract 38, is preferably faced with a block of felt 58 in a. usual manner, also the oppositely disposed angularly arranged

upper end faces

36 and 37 are similarly faced with leather, as at 59 and 60 respectively. As shown in Figure 1, the rest rail 46 is supported in proper position directly on the upper flat face of the forwardly7 offset shoulder 20, of the frame 13. The upper face of the shoulder 2O is preferably provided with a block or strip of felt 47 to cushion the rest rail 46 thereon in a usual manner.

Supported on the shoulders 19 at the rear of the upper portion 16, of the frames 13 is a supporting rail 61 to the upper side of which is secured, by means of the screw 62, a bracket or flange 63. which projects rearwardly of the rail 61, and pivotally supports at its outer end, as at 64, a damper lever 65. Rising from the upper end of the lever 65 is a rod 66, which has a damper 67 secured at its upper end for cooperation with the ter is forced upwardly on its pivot32, durying the fingering of thefkey l0.' The opposed faces of the extension '68 and the portion 31', of t-he butt 31, are faced with strips of felt 69 and 70 respectively, in a usual manner. Secured, as at 71, to the iiange 63 is one end portion'of a spring 72, which hasv its'free end projecting upwardly from its point of connection aforesaid and arranged to bear against the kforward side of the upper portion'of the lever y65 in a manner that the damper isnormally tensioned by the same againstthe string 11. r1`he rear side of the upper edge portion ofthe main or supporting rail 21 is channelled to partly house withinthe same a sustaining or loud pedal rod 73, which/coacts'with the lower end of the damper lever 65. The opposed faces of the damperlever and the vertical wall of this channel are faced with strips of felt-74 and 7 5',`.,respectively, and the latter strip of felt 7 5 being extended'forwardly over the top edge ofi` the main'isupporting rail 21 in a manner-to be contacted by the felt on the rear vportion 31 ofthe butt 31, when the latterfis swung upwardly and rearwardly on its pivot'32.

Rising vertically at the forward side of the frame 13 Vis a. rod'7 6, whichis connected at its lower end to the usual soft pedal (not shown), and has its upper end engaged in asocketl or recessformed in the under side of Hthe'restrail 46l in a manner that, when the rod 76 is moved vertically by the actuation of the soft pedal, the restrail 46 is tilted in a rearward direction, which rearward movement'forces against the post 43, and through the head44, also against'the hammer 42, so that the butt 31 is swung upwardly and rearwardly on itsv pivot 32. By sustaining the rod 76 in its raised position, the hammer 42 is correspondingly sustained in a closer positionto the string 11, so that'its stroke is shortened and the resultant tone ofthe string 11 is softened, when the'kev 10 is fingered. To assure of the uniform tiltingmovement of the hammer or rest rail 46, underthe lifting action ofthe soft pedal rod 76, a lever 77 is secured atY its upper end, by means of screws 78 to the restrail 46, and is pivoted at i an intermediate point, as at 7 9, to the frame 13. Secured to the lower end of the lever 77, by meansfof the screw 80, is the upper guide rail 52, which, when the upper endv of the lever is forced rearwardly by the tilting ofthe hammer orrest rail 46, under the actionl of thel soft pedal rod 76, is moved in a forward'direction with the lower end of the per end'of'the abstract 38, moving the lat# terfin-'a,forward direction, so that the `anguv lar or linclined end 'faces 36 and 37 disengage from thevinner of the inclined-or stepped faces 34, of the butt 31, and engage with the forward or outer of the latter faces 35. By now fingering the key 10, the abstract 38 will actuate the butt 31 in the usual manner, but the hammer 42 will strike the string 11, with less force by reason of its shortened strokeu In the operation of the action, an impulse is transmitted from the key 10 to the butt 3l through the abstract 38. r1`he upper and rearwardswinging movement of the butt 31 on its pivot 32 carries with it the post 43, the head 44 of which, in turn, forces against the hammer 42, and actuates the latter into striking engagement with the string 11. The rearward throw of the hammer 42 is limited by the string 11, and the latter, after beingl struck, acts to automatically return the hammer to its forward position, when the shank 40 will engage with the rear ends of the loop 45. With the engagement of the shank 40 between the ends of the loop 45, connecting the head 44, the hammer is restrained against rebounding back against the string 1l by such engagement as well as by the action of the spring 51, which as has been hereinbefore explained, acts to normally tension the shank 4G against the post 43. With the

angular shoulders

36 and 37 at the lupper end of the abstract 38 engaged with the inner of the stepped or inclined shoulders 34 at the lower side of the butt 31, the rearward throw of the latter and the hammer 42 is maximum, and consequently the volume ofsound from the string 1l is also maximum when struck by an impulse imparted to the hammer 42 from the key 10. Now, when ythe soft pedal rod 76 is elevated, the rest rail 46 is tilted in a rearward direction, andmoves the post 43 and the hammer 42 to a position nearer the string ll'and, at the same time, the lever 77 is swung on its pivot 79, so `that its lower end swings the rail 52 forwardly against thc abstract l38, and moves the upper end of the same in a corresponding direction, so that the

shoulders

36 and 37 thereof pass from the shoulders 3 side of the butt 31 as has been hereinhcfore explained. With the parts sustained in this position, the throw ofthe butt 31 and the hammer 42 is shortest and'consequently the volume of sound given off -from the string 11 will be minimized, when struck by the hammer.

Vithout further description, it is thought that the features and advantages of the in-` vention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention or its-scope as claimed.

Having thus fully described the invention, what "is claimed is z to the shoulders 35 at the lower 1. In a piano action, a hammer having a butt, an abstract for transmitting impulses to said butt, and means adapted to be actuated by the soft pedal of the iano for automatically shifting the point o? engagement of the abstract and butt to vary the stroke of the hammer correspondingly with the operative movements of the soft pedal.

2. In a piano action, a hammer having a butt, shoulders spaced alongr the under side of said butt, an abstract slidably engaged with the butt and adapted to be alternately engaged with said shoulders, and means for shifting the abstract with respect to said shoulders to vary the stroke of the hammer.

3. In a piano action, a hammer having a butt, shoulders spaced along one side of the butt, an abstract slidably engaged with the butt and adapted to be alternately engaged with said shoulders, and means adapted to be actuated by the soft pedal of the piano for shifting the abstract with respect to said shoulders to vary the stroke of the hammer correspondingly with the operative movements of the soft pedal.

4. In a piano action, a hammer having a butt, angularly disposed shoulders spaced along the under side of the butt, an abstract slidably engaged with the butt and adapted to be alternately engaged With said shoulders, and means adapted to be actuated by the soft pedal of the piano to shift the abstract With respect to said shoulders to vary the stroke of the hammer correspondingly with the operative movements of the soft pedal.

5. In a piano action, a hammer having a butt, a rest rail for the hammer, an abstract for transmitting impulses to said butt, means controlled by the soft edal of the piano for moving the rest rail rom normal position, and means movable with the rest rail for shifting the abstract with respect to the butt to vary the stroke of the hammer correspondingly with the operative movements of the soft pedal.

6. In a piano action, a hammer having a butt, a rest rail for the hammer, an abstract for transmitting impulses to said butt, means controlled by the soft edal of the piano for moving the rest rail rom normal position, means for shifting the abstract with respect to the butt to vary the stroke of the hammer, and means connecting the rest rail for imparting movement to said last-mentioned means correspondingly with the action of the soft edal controlled means.

7. n a piano action, a frame, a hammer having a butt, a rest rail supported on said frame, an abstract for transmitting impulses to said butt, means controlled by the soft pedal of the piano for moving the rest rail from normally supported position, a member pivotally supported on said frame and connecting said rest rail for movement therewith,

and means carried by said member for shifting the abstract with respect to the butt to vary the stroke of the hammer correspondingly with the operative movements of the soft pedal.

8. In a piano action, a frame, a hammer having a butt, a rest rail supported on said frame, an abstract for transmitting impulses to said butt, means controlled by the soft pedal of the piano for moving the rest rail from normally supported osition, a lever pivoted intermediate its en s to said frame and having one end engaging the rest rail for movement therewith, and means carried at the other end of said lever for shifting the abstract with respect to the butt to vary the stroke of the hammer correspondingly with the operative movements of the soft pedal.

9. In a piano action, a frame, a main rail supported on said frame, a butt pivotally supported on said main rail, a hammer carried by said butt, an abstract for transmitting impulses to said butt, a rest rail for said hammer supported on said butt, a member adapted to be actuated by the soft pedal of the piano for moving said rest rail from normally supported position, an elongated member pivotally supported on said frame and connecting said rest rail for movement therewith, and means carried by said member for shifting the abstract with respect to the butt to vary the stroke of the hammer correspondingly with the operative movements of the soft pedal.

10. In a piano action, a frame, a main rail carried by said frame, a flanged member carried by said main rail, a butt pivoted to said flange, a hammer carried by said butt, means for operating the butt for the actuation of the hammer, and means for shifting said lastnamed means relative to said butt to vary the stroke of the hammer correspondingly with and by the operative movements of the soft pedal mechanism of the piano. Y

11. In a piano action, a frame, a main rail supported on said frame, a flange rail mounted at one side of and to said main rail, a fiange carried bv said flange rail, means for adjusting said flange rail longitudinally of said main rail, a butt pivotally mounted on said iiange, a hammer carried by said butt, means for operating said butt for the actuation of the hammer, and means for varying' the stroke of the hammer correspondingly with and by the operative movements of the soft pedal mechanism ofthe piano.

12. In a piano action, a frame, a main rail supported on said frame, a flange rail adjustably7 mounted on said main rail, a `flange carrie by said iange rail, a butt pivotally mounted on said fiange, a hammer carried by said butt, means for operating said butt for the actuation of the hammer, and means for shifting said last-named means relative to said butt to vary the stroke of the hammer correspondingly with and by the operative movements of the soft pedal mechanism of the piano.

13. In a piano action, a pivotally mounted butt, means for transmitting key impulses to said butt, and a hammer movable with said butt and pivotally mounted for relative movements thereon, said means being shiftable along said butt to vary the stroke of said hammer.

14. In a piano action, a pivotally mounted butt, means for transmitting key impulses to said butt, and a hammer movable with and mounted on said butt for limited movements relative thereto, said means being shiftable along said butt to vary the stroke of said hammer.

15. In a piano action, a pivotally mounted butt, means for transmitting key impulses to 2G said butt, a hammer movable with and mounted on said butt for limited movements relative thereto, and means for preventing accidental repetition strokes of the hammer, said first-named means being shiftable along the lower side of said butt to vary the stroke of said hammer.

16. In a piano action, a vertically movable butt, a hammer carried by said butt, angularly displaced shoulders formed on said butt,

and means for transmitting key impulses to said butt and said hammer, said means being shiftable from engagement with one of said shoulders to another thereof to vary the stroke of said hammer.

17. In a piano action, a pivoted butt, a hammer carried by said butt, angularly dis placed shoulders formed at the lower side of said butt, and means for transmitting key impulses to said butt and said hammer, said o means being shiftable from engagement with one of said shoulders to another thereof to vary the stroke of said hammer.

18. In a piano action, a pivoted butt, a hammer carried by said butt, angularly dis- 5 placed shoulders formed on the lower side of said butt, means interchangeably engageable with said shoulders for transmitting key impulses to said butt, and means for shifting said last-named means from engagement with one of said shoulders to another thereof to vary the stroke of said hammer.

19. In a piano action, a pivoted butt, a hammer carried by said butt, angularly displaced shoulders formed at the lower side of said butt, means interchangeably engageable with said shoulders for transmitting key impulses to said butt, and pedal operated means for shifting said last-named means from engagement with one of said shoulders to another thereof to vary the stroke of said hammer.

BERNHARD F. LAUKANDT.