US1598203A - Piano action - Google Patents

Description

Aug. 3l 1926. 'y l 1,598,203

B. F. LAUKANDT PIANO ACTION Filed July l0. 1923 I5 Sheets-Sheet l J. V-l

WITNESSES IN VEN T OR, P F. Laukandl Ukwwuda f I B11/MAM A TTORN E YS B. F. LAUKANDT Augy PIANO ACTION 3 Sheets-Sheet 2 Filed July lO, 1923 WITNESSES A TTOR NE YS Aug. 31 1926. 1,598,203

B. F. LAUKANDT PIANO ACTION Filed July 10, 1923 3 Sheets-Sheet 3 WITNESSES maar ATTORNEYS Patented Aug. 3l, 1926.

UNITED STATES BERNHARD FRANK LAURANDT, or RED WING, MINNESOTA.

PIANO ACTION.

Ap'pncaaon med any 1o, 1923. serial No. 650,704.v

l This invention relates to an improvement in piano actions, and has for its object, first, to insure a greater rythmic precision by eliminating all lost motion in the action, second, to obtain a quick repetition of the hammer strokes with less finger motion than is required by the ordinary standard action, and third, to reduce the number of parts in action to a minimum without sacrificing any of the advantages' attached to the old standard actions.

Other objects and advantages of the invention reside in certain novel features of the construction, combination and arrange- 'ment of arts which will be hereinafter more fu ly described and particularly pointed out in the appended claims, reference being had to the accompanying drawings fo'rming part of this specification, and in which:

Flgure 1 is a fragmentary view in elevation, showing the piano action embodying the present invention together with the 'frame thereof;

' Figure 2 is a fragmentary View, partly in section and partly in elevation, showing the piano action at rest;

Figure 3 is a similar View, showing the hammer action in striking position;

Figure 4 is a W'ew similar to Figures 2 and` 3 but showing the action adjusted for softer playing;

Figure 5 is a fragmentary view in perspective, showingL tle construction of the up er end of an extension rod;

igure 6 is a view similar to Figure 5, showing the extension rod in elevation;

Figure 7 is a fragmentary detail view, partly in section and partly in elevation and showing the hammer construction;

Figure 8 is a wview in elevation, showing the manner in which the pedal controls are mounted on the frame; and

Figures 9 and 10 are detail views.

Referring to the drawings wherein for the sake of illustration is shown the preferredembodiment of the invention, numeral 10 designates aconventionaltkey which is mounted in the conventional manner and the numeral 11 designates the strings of the piano. The piano action is designated generally at 12 and is mounted onjframe membersv y13 constructed as shown in Figures '1 m18 ,and ela/sh ,inclilina .a .verticale bar. 14

f having ma supporting 'Shpaiaers 15 integral therewith and also having an inclined bar 16 connected by cross pieces 17 with the vertical bar and serving with the vertical bar to support an extension 18 providing rail supports 19 and 20.

The piano action 12 includes a main or supporting rail mounted on horizontally alined shoulders 15 of the frame members. A hammer designated generally at 26 is provided and includes a butt or central lever 27 pivotally supported, as at 28, upon a flange 29 carried by the supporting rail A shank 30 is embodied in the hammer and bifurcated at its lower end, as at 31, the arms of the bifurcation embracing the butt 27 and beingk pivotally secured thereto, as at 32. The upper end of the shank 3() has xedly secured thereto a hammer head 33 constructed, as shown in Figure 7, and having its body 34 provided with an axially extending cylindrical cavity 35, the ends of which are equipped with pads of felt, designated at 36. A weight 37 encased in leather or other suitable material, designated at 38, is arranged in the cavity so as to be freely shiftable therein. At each end of the cavity vents 39 are provided which permit of free escape and admission of air whereby rthe movement of the weight 37 isv not interfered with. A removable plug 40 pinned or otherwise suitably secured to the body 34 is provided at one end of the body so as to permit of assembly of the weight in the cavity. A post 45 has its lower end secured to the butt 27 and-extends upwardly therefrom, the post being inclined slightly with respect to the vertical. At its upper end the post 45 is headed, as at 46, and to this head 46 a leather strap or loop 47 is fastened, the loop 47 embracing the shank 30 of the hammer. The post 46 serves to drive the hammer or to transmit the impulses thereto from the butt, and also serves as a back-check therefor. When the action is at rest the post 45 lays against a rest rail 50 which is faced with felt in the usual manner. Also when the action is in the striking position the tail of the butt has its block vof felt 51 engaged with thefelt surfacing vof a check rail 52 mounted on the rail support 20 of the frame member so as toy check the movement of the` butt or central -lever.` The fhammer 26 is so mounted and balanced that'under thenction of gravity Vit tehdst seek the position shovvn in Figures 1 and the post -i lying against the rest rail 50 and the shank 30 laying bael; against the portion ot the strap ivliicli is connected to the head "6 oi the post 4:5, as shoivn in detail in Figure 9. In order to supplement the action of gravity in this respect the light spring 53 is employed and is Connected to the butt 27 and to the Shank 30 tor the purpose of tending to swing the shank EO toivard the post- ;Jf and against the strap l? thereof as shoivn in Figures l7 l and Sl. fils a light spring 2L iiiav be employed and may be connected to the. main rail Q5 and. butt 2T to siving the central lever to the position slioivn in Figgiires l, t? and Je? these light springs'being eonstructef, and arranged as shoivn in the drawings.

A damper desigi ated generally at provided and 'is rigidly supported ot a heavy wire 5G. upon de i 5T liivotally mounted; as at 'i 59 Carried by the damper rail t the uppermost rail support iienibers. The damper lever 'A engaged by the bitt n.7, :is .slioivi ii i Si light spring' 6l is mounted o2 tianrre 59 and engages the rail GO and damper lever 5T and tends to i tiirii the damper into engagement with its ,fitr-ing.

The impiilse directly transmitted iroiii the key l() to the butt or ventral lever QT bv means ot an vtenslon rod G5, the loiver eiid o1" vfliicli is connected tothe liejv liv caps-tan screiv 66 havingr a holloiv Cap (iT to receive the loiver end ot the rod. lt :s to be understood that the loiver end fit the extension rod G5 tits or stands loos cavity provided therefor in the lifcapstaii sereiv so as to permit action to be realil f reiiiovefl.

e loiver tapers tovvarf.. i end it headed o' is bitiireatcd, at G9, to proi flanges T() which engage on t; sides of the central lever or l; ii

the head GC lvine' in beiive siiriiaeed b v ifelt or the nire? as id is adapted slidable niid eneageinent vritli the i t The point at which the e ension rod engragfjes the butt is controlled s pedal of the piano and for this `irpose a crank shaft is mounted. on

portion ot 'flanges T0 the traine nien'iliers and Connected ivitli the extension rod by means ot a strap be ing or bracket T3 ivliicli with the rod provides a slot T-liii which the crank operates. At one end tlie crank TQ provided ivith an arin T5 connected by a pedal rod 'T6 with the pedals (not sliorrn)A A similar crank .78 is provided for the dainier and Coacts ivith the loiver i rm of the nani-per levers 57, as indicated in Figures l, Q and Also one end of the cranl '7S is provided ivitli an arn T9 connected by a pedal rod 8O with the loiid pedal iii :,peafion f ironi lever tliroiigh ,'-gei'ifion swinging olf' the biitt about its pivot 28 eari ries vvitli it the post l5 ivliieh in turn drives or actiiatcs the sliaiil; 30 o't the liiiiiinier so as to tliroiv the hammer head into f-ti'ilviiigr eii` ement ivitli the eti-inns. rThe forward throiv ot' the slianlr and ha iiiiier ii ad 251% ie li iiited only by the string oit the piano against ivliieh the iiain ner lieiifl and vvhicl zitter the striking :iets to automatifallj. lliroiv the liainmerrhefid flI-S aivay troni :ind the shank 530 into engagement vitli the rear ends of the loop iT next to the post head elfi. liloivever. as shown in liig. 2:3T the :irranaeinent is siieli that the haiiiiner liefifl and its shank lill), that is the hammer propeiz has, a ver): short forward movement iter the movement ot the butt 2T hais1 been ieelzei by Contact ivitii the check rail ie dotted lines in lllignii'ey .il iinlicating the mall but almost iiistaiitaneoiis movement of the hammer proper between the post 443, the iiaiio string` and back to the post again. This operation has many :idvantiiiis and is: believed to constitute an important 'feature of this invention. The loop er .strap "l-T serves to malte the hi iiinier tollow the backivari'l movement oi?) the post -li vvlieii :i nerf stroke is desired or ivlien the post to re-v tiii'n to Vthe rst rail Fill. lt also sei'ves :is a haelt-cheek on the return iiiovr-inieiit o't the hammer. The sliitizible ive-ight 3T in the hammer head serves to absorb the recoil of the hammer and thus to prevent it from restrilting the string on its oivn accord. The Conjoint action of the sliittiable Weight 3T and the leather .strap 4T to the end of overcomingr and aborbinfir the recoil from the string zitter a forcible bloiv constitutes an ie to a .s te ot rest ivlienj oi its recoil, itv returns .into enfi'agenient ii.' th the rear ends ot the Straps -Y-.YT adjacent the post head a6 and that tlie strap lfT being sott and yieldable does not react to tend to canse the hamnier bead to rebound tlieretroiii. The damper is released by the direct and posi,- tive action ot the butt and the movement of the britt is limited in a positive and efective niaiiner bjr its engagementivith the check rail.

Sat the saine time the mechanism is readilv adjustable for sott playing, the stroke of hammer being varied for this purpose by a. simple adjiistii'ientof the extension rod llt) with respect to the butt. For soft playing the soft pedal is pressed and the crank 72 is thereby rotated to swing the extension rod in a. clockwise direction as viewed in Figures l, 2 and 3 and to the position shown in Figure 4 whereby the stroke of the hammer is shortened, thereby softening the impact of the hammer as will be apparent from a consideration of Figure 4.

I claim:

l. In a piano action, a supporting rail, a hammer having a butt svvingably connected to the supporting rail and having a head actuated from the butt and mounted for limited swinging movement relative to said butt, an extension rod engaged with the under side of kthe butt ofthe hammer, a check rail engageable with the upper side of the butt, a damper havin a lever adapted to be engaged by the butt of the hammer.

2. In a piano action, a supporting rail, a hammer having a butt svvingably connected to the supportinfv rail and having a head actuated from the butt and mounted for limited swinging movement relative to said butt, an extension rod engaged with the under side of the butt of the hammer, and a check rail engageable with the upper side of the but-t.

3. In a piano action, a supporting rail, a hammer including a butt swingably connected to the supporting rail, a shank pivotally connected to the butt,-a head carried by the shank, a post fixedly secured to the butt at the rear end of the shank and co-operable with the shank for imparting an impulse thereto, and a loop carried by the post and embracing the shank, and an extension rod engaged with the underside of the butt of the hammer.

4. In a piano action, a hammer including a butt, a shank pivotally connected to the butt, a head carried by the shank, and a post fxedlv secured to the butt to the rear of the shank, and cooperable with the shank for imparting an impulse thereto.

5. In a piano action, a hammer including a butt, a shank pivotally connected to the butt, a head carried by the shank, a post fixedly secured to the butt to the rear of the shank, and a loop carried by the post and embracing the shank.

6. In a piano action, a hammer having a head provided Wit-h an axial cavity, and a freely shiftable weight arranged in saidcavity.

T. In a piano action, a hammer having a head provided with an axial cavity, a freely shiftable Weight arranged in said cavity, and means for cushioning the impact of the Weight with the Walls of the cavity and butt, and manually shiftable means having a loose connection With the extension rod for controlling the point of engagement of the extension rod With the butt whereby the stroke of' the hammer may be varied.

l0. In a piano action, a hammer having a butt, an extension rod having its upper end -bifurcated and slidably and adjustably engaged with said butt, and means coacting with the extension rod for controlling the point of engagement of` the extension rod with the butt whereby the stroke of the hammer may be varied, said means including a crank and a bearing strap secured to the extension rod and embracing the crank.

l1. In a piano action, a hammer including a butt, a shank pivotally connected thereto, a head carried by the shank and having a freely shiftable Weight therein, a post fixedly secured to the butt to the rear of the shank, and means carried by the post and providing a yieldable seat for the sha-nk.

l2. In a piano action, a hammer including a butt, a shank pivotally connected thereto, a head carried by the shank and having a freely shiftable weight therein, ay post fixedly secured to the butt to the rear of the shank, and a loop of flexible and yieldable material embracing the shank and having its ends disposed in and secured to the post to effect return movement of the hammer and to provide a yieldable seat for the shank thereo y 13. In a piano action, a hammer including a but-t, a shank pivotally connected thereto, a head carried by the shank, a post tixedly secured to the butt to the rear of the shank, and means carried by the post and providing a yieldable seat for the shank.

14. In a piano action, a hammer including a butt, a shank pivotally connected thereto, a head carried by the shank, a post fixedly secured to the butt to the rear of the shank, and a loop of flexible and yieldable material embracing the shank and having its ends disposed in and secured to the post to effect return movement of' the hammer and to provide a yieldable seat for the shank thereof.

BERNHARD FRANK LAUKANDT.

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