US1900488A

US1900488A - Piano action

Info

Publication number: US1900488A
Application number: US570995A
Authority: US
Inventors: Charles H Dasenbrook
Original assignee: THAYER ACTION Co
Current assignee: THAYER ACTION Co
Priority date: 1931-10-26
Filing date: 1931-10-26
Publication date: 1933-03-07
Anticipated expiration: 1950-03-07

Description

March 7, 1933. c; H, DASENBROK 1,900.488

PIANO ACTION Filed Oct. 26, 1951 Z SheetS-Sheet 1 Inverna/ $7 WWW+ W.

March 1933- c. H. DASENBROOK ,900,488

PIANO ACTION.

Filed 001;. 2a 1931- ZShets-Sheet 2 Patented Mar. 7, 1933 UNITED STATES CHARLES H. DASENBROOK, F ROCKFORD,

ILLINOIS, ASSIGNOR TO THAYER ACTION COMPANY, OF ROCKFORD, ILLINOIS, A CORPORATION OF ILLINOIS PIANO ACTION Application filed October 26, 1931. Serial 110,570,995.

This invention relates in general to the improvements in grand piano actions and more particularly to a so called simplified action in which the functions of the conventional repetition lever and associated parts are performed by a metallic spring.

The general object of the invention is to provide a novel repetition spring in a piano action of the above character whereby to duplicate the key touch, the rugged construction and the reliability of operation of repetition mechanisms heretofore employed while at the same time greatly simplifying the construction of the action and reducing the cost of manufacture accordingly.

More particularly, the invention resides in the novel construction of the repetition spring, in the new and improved manner of mounting the same, and in the novel construction of the different spring stops.

Other objects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Figure 1 is a fragmentary side elevational view of a grand piano action embodying the features of the present invention, the parts being in the positions which they assume just prior to withdrawal of the jack while the 39 key is being depressed.

Fig. 2 is a perspective View of a portion of the mechanism shown in Fig. 1. p

Fig. 3 is a view similar to Fig. 1 showing a modified form of the invention with the parts in normal position of rest.

Fig. 4 is a view similar to Fig. 3 showing different positions of the parts.

F ig. 5 is a perspective view of the modified form of repetition spring. G In the exemplary form shown in the drawings, the numeral 6 indicates the conventional form of key lever carrying the backcheck 7 and the capstan screw 8 which latter enga es the whip 9 and throws the same up- :5 ward y upon depression of the key. Herein the whip is pivoted at 10 upon an arm 11 depending from a rail 12 which carries the rebound cushion. The butt 14 of the hammer is pivoted at15 on the forwardly pro- 0 jecting flange 16 of a rail 17 and carries a limited by engagement of an adjustable and forwardly projecting button 24 on the jack with a vertical post 25.

The present invention contemplates a novel repetition spring indicated generally by the numeral 26 which is simple and inexpensive to construct and assemble in the action, which requires no mechanical adjusting means, which is suited for use with several differently Weighted hammers, which operates at maximum mechanical advantage in sustaining the weight of the hammer during recovery of the jack, which utilizes to advantage the upward movement of the whip in increasing the spring effect thereby permitting the use of a relatively light spring construction. To this end a spring is employed which has an elongated substantially straight portion 27 extending in a direction generally parallel to a line betweenthe

axes

10 and 15 and a reversely bent portion 28 which enables the spring to be anchored near the end of the whip remote from the pivot there- Preferably, the spring is of the hair-pin type being composed of a single length of resilient wire bent at its center so that the

portions

27 and 28 are each composed of two parallel parts spaced apart to receive the upper ends of the jack 19 and the post 25 between them. The upper or closed end portion 27 is bent downward slightly at its free end and adapted to engage-a cushioned button 29 the stem of which is threaded into the butt flange 16 beyond the axis 15. In this way the button 29 acts as a stop for limiting the backward movement of the jack 19 and the button is located close to the knuckle 18 v a made woodwi-th a heavy base 3l' (Fig. 1)

having parallel sides. In this preferred form of spring, the lengths of wire forming the open "end portion 28,,aresubstant1ally straight. and disposed in" horizontal grooves 32 formed in the opposite sides of the post. The ends of the Wire are bent toward each other and project into the post at one end ofthc groove thereby effectually anchoring such ends the opposite ends of the groove, the wires are'firmly anchored by tacks 33 driven into the post with'their heads overlying the wires. 1 In this way the unsupported portions of the wires are firmly held againstilateral as well as vertlcal' movement and this combined with the doublerwire construction gives a substantial degree of lateral rigidity to the spring as a whole enabling e the parts of the closed end portion 27 to be spaced relatively close to the p0st'25 and the jack 19and yet maintained at all times out of rubbing contact'therewith.

It will be apparent that the entire length of spring between the point of contact with the knuckle l8 and the point of anchorage in the post 25 is rendered effective with the mounting above described. Thus, the spring possesses ahighdegree of fleXibility and is of substantially uniform strength regardless of ordinary variations in construction and mounting during manufacture. For this reason, no provision for adjustment is required and springs of the same size wire may be used forseiteral differently weighted hammers'and'only a few different s zes of Wire are required for all of the hammers 1n the 1 action. anchoring the spring at a'point remote from the whip pivot'lO, that is, adja cent the jack 19,-it-will be observed that full advantageis taken of the upward movement of the whip inbending the springdownwardly and thereby increasing the spring effect the time when the spring comes into play in sustaining the weight of'the hammer during recovery o f the jack. The spring may therefore be made of; minimum weight and high flexibility therebymaking for greater uniformity in the construction of the springs.

Another way of anchoring the spring in the base of the post 25 isillustratecl in Figs. 3 and 4 In this instance the ends 34k of the wire forming-the. spring are bent downwardly into substantially right angular relation with respect to the portions 28 and secured to the postin the samemanner as in the, formfirst described which latter, is preferred because of the greater lateral rigidity obtained. f v The rest 5. s lseu ili e .1 me s for preventing application of the spring effect shoulder 35 which is padded with a piece of a felt 36 and isi of sufiicientleng'th of (iverlie the legs 27 of the spring and engage the same J as shownin Fig. 2. Application of spring pressure to the hammer when the parts are in idle position is thereby prevented. With the shoulder thus located, the costof attaching the pad 36 is reduced to a minimum inasmuch as it may be applied in strlp form to a plurality of postsrlisposed side by side.

Preferably the shoulder 35 is formed on the post directly opposite fromthe jack in order to form an obtuse anglewiththe side of the I post withwh ich it intersects thereby further facilitating attachment of the pad 36 Assumingthe parts to be in idle position (Fig. 3), the action operates as follows.

When the key is depressed, the whip is thrown upwardly and its motion transmitted I to the hammer through the jack. The latter is withdrawn from beneath the butt knuckle 18 as the arm 2Q engages the stop 21 and the I momentum of the hammer carries the latter upwardly against the string If the blow is a sharp one andthe-key is held depressed thereafter, the back-check 7 comes into play as shown in full lines in Fig. 4 and the spring 26 is movedaway from the shoulder 36 and the stop 29 thereby exerting its force on the Ina similar way as shown in v hammer. v dotted outl ne in 4, the spring 26is out of contact with the shoulder 36 and engaging the butt knuckle following a-light 'blow'.

the stop 29 is positioned to limit t-he nove" ment of hammer by the spring to a point where the jack just engagesthe knuckle in recovering the operator senses the reco very of the jack-the. same asin conventional piano actionsusing repetition levers. In this way the key touch of present day actions is closely simulated and all of the functions of the conventional repetition lever and associated parts are performed by the spring 26 which can be'manufactured and assembled" the ct o a ewb n a y du ed o ti- I claim. as, myinvention: i

1. In a piano action, the combination of v a pivot ally mounted hammer having a butt Now as the key is released under either of I knuckle, a pivotally mounted whip adapted to be actuated by depression of a. key, a jack pivoted on the free end of said whip and adapted toengage at its free end with said knuckle, a post rigid with and upstanding from said whip adjacent the jack pivot, and an elongated repetition spring bent intermediate its ends to form an acute angle between its end portions, one of said portions extending in a'direction generally parallel to said whip and anchored in said post,

the other end portion of said" spring extending substantially parallel to a: line through the axes of said whip and hammer with its free end adapted-to-engage said knuckle whereby to sustain the weight of the latter during recovery of said jack.

2.In a piano action, the combination of a pivotally mounted hammer having a butt knuckle, a pivotally mounted whip adapted to be actuated by depression of a key, a jack pivoted on the free end of said whip and adapted to engage at its free end with said knuckle, a post rigid with and upstanding from said whip adjacent the jack pivot, an elongated spring of the hair-pin type bent intermediateits ends to form an acute angle between its open and closed end portions, the ends of said open portion lying on opposite sides of said post and rigidly anchored therein, the wires forming said closed end por tion being disposed on opposite sides of said post and said jack and adapted to engage said knuckle adjacent the closed end of the spring.

3. In a piano action, the combination of a pivotally mounted hammer having a butt knuckle, a pivotally mounted whip adapted to be actuated by depression of a key, a jack pivoted on the free end of said whip and adapted to engage at its free end with said knuckle, a post ri id with and upstanding from said whip a jacent the jack pivot, an elongated piece of resilient wire bent at its center to form a spring of the hair-pin type bent intermediate its ends to formopen and closed end portions extending at an acute angle to each other, substantial lengths of the wires forming said open portion being disposed in grooves on opposite sides of said post with the ends of the wire bent toward each other and projecting into the post near one end of said grooves and tacks driven into the post adjacent the opposite end of the grooves with their heads overlying the wire, the closed end portion of said spring being arranged for engagement with the under side of said knuckle.

4. In a piano action, the combination of a pivotally mounted hammer having a butt knuckle, a pivotally mounted whip adapted to be actuated by depression of a key, a jack pivoted on the free end of said whip and adapted to engage at its free end with said knuckle, a post rigid with and upstanding from said whip adjacent the jack pivot, an elongated piece of wire bent at its center to form a spring of the hair-pin type having open and closed end portions with the former anchored in said post, said closed end porpivoted on the free end of said whip and F adapted to engage at its free end withsaid knuckle, a post rigid with and upstanding from said whip adjacent the jack pivot, an elongated piece of wire bent at its center to form a spring of the hair-pin type having open and closed end portions with the ends of the wire disposed on opposite sides of said post and anchored therein to support vsaid closed end portion, the lengths of wire forming the latter being disposed on opposite sides of said post and jack and spaced so as to be out of rubbing contact therewith but'engageable with said knuckle, and cushionedshoulders formed on said post at the upper end thereof to limit upward flexing of said sprin 6. n a piano action, the combination of a pivotally mounted hammer having a butt knuckle, a pivotally mounted whip adapted to be actuated by depression of a key, a jack pivoted on the free end of said whip and adapted to engage at its free end with said knuckle, a repetition spring of thelhair-pin type having an elongated substantially straight closed end portion extending in a Y direction generally parallel to a line through the axes of said hammer and whip and adapted to engage the under side of said knuckle, and a single post rigid with and upstanding from said whip providing an anchor for the open end portion of said spring and a stop for limiting the upward movement of saidclosed end portion. A

7. In a piano action, the combination of a pivotally mounted hammer having a butt knuckle, a pivotally mounted whip adapted to be actuated by depression of a key, a jack pivoted on the free end of said whip and adapted to engage at its free end with said knuckle, an elongated repetition spring supported by said whip and having a vertically movable substantially straight portion adapted to engage said knuckle, a post rigid with and upstanding from said whip and having a shoulder constituting a stop for limiting the upward movement ofsaidportion and formed on the'side of said post adjacent said jack, said shoulder extending across the entire width of the post and pro- I jecting beyond the opposite sides thereof,

and a strip of cushioning material on the surface of'said shoulder. 1

' 8. In a piano action, thecombination of a pivotal'ly mounted hammer having a butt knuckle, a pivotally mounted whip adapted to be actuated by depression of a key, a jack pivoted on the free end of'said Whip and adapted to'enga ge at its free end with said kniiclilie',an elongated repetition spring supported by said whip and having a vertically movable" substantially straight portion adapted to el-igage saidknuckle,and a post i. no

rigid with and upstanding from said whip and having an elongated shoulder extending transversely of said post with its ends projecting beyond opposite sidesthereof and providing stops for engaging" saidportion and thereby limiting upward "movement thereof, the plane of the shoulder. surface forming an obtuse angle with the side of the post from which the shoulder is out. w

9. In a piano action, the combination of a pivotally mounted hammer having a butt knuckle, a pivotally mounted whip adapted to 'be'actuated by depression of a key, a jack pivoted on the free end of said whip and adapted to engage at its free end with said knuckle, an'elongated repetition spring supported by said whip and having a vertically movable substantially straight portionadapted to engage said knuckle, and a post rigid with and upstanding from said whip and having a downwardly facing, shoulder formed by :l-rollowing out said post on the side alongwhich said spring portion extends, asecond shoulder intersecting said firstmentioned' shoulder and formed by hollowing out key, a jackpivo-tedon the free-end-ofsaid whip and adapted to engage atitsfree end with saidknuckle, a post rigid with and'upstanding from said, whip adjacent the jack pivot, an elongated wire member bent intermediate its endstoformtwo substantially straight legs projecting toward said 7 jack at an acute angle relative to each other, one extending in a generally'horizontal direction and having its free end anchored in said post at a point spacedabove'said jack, the other of said legs extending upwardly toward said jack and engageable, adjacent its free s end with said, knuckle, and a cushioned shoulder on said post actingv on said last mentioned leg intermediate the ends thereof to limit upward flexing thereof; t Y

. In testimony whereohl'have hereunto affixed my signature; g CHARLES DASENBROOIQ;

a side of said post disposed transversely of said springportion, and cushioning means secured to and extending along said'second shoulder and overlapping a portion of'said first mentioned shoulder. V v V 10. In a'piano action, the combination of a 3 rail with a flange projecting therefrom, a hammer having itsbutt end pivoted on said flange, a key-actuated whip, a Jack pivoted onsaid whip and adapted to engage a butt vknuckle on said butt end, an elongated repetition spring supported from one of its ends 7 i by said whip and having the other end'extending in a direction substantially parsaid flange between theedge thereof and the axis of; said'h ammer soas to be disposed close to said knuckle, and a button on the end of said screw providing a cushioned stop for the freeend of said spring and for limiting the withdrawing movement of said jack.

11. In a piano action, the combination of a pivotally mounted hammer having a buttyknuckle, a pivotally mounted whip adapted to be actuated by depression of a