CA2199783A1 - Piano escapement action - Google Patents
Piano escapement actionInfo
- Publication number
- CA2199783A1 CA2199783A1 CA002199783A CA2199783A CA2199783A1 CA 2199783 A1 CA2199783 A1 CA 2199783A1 CA 002199783 A CA002199783 A CA 002199783A CA 2199783 A CA2199783 A CA 2199783A CA 2199783 A1 CA2199783 A1 CA 2199783A1
- Authority
- CA
- Canada
- Prior art keywords
- jack
- knuckle
- piano
- retainer
- spring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10C—PIANOS, HARPSICHORDS, SPINETS OR SIMILAR STRINGED MUSICAL INSTRUMENTS WITH ONE OR MORE KEYBOARDS
- G10C3/00—Details or accessories
- G10C3/16—Actions
- G10C3/168—Actions with hanging jacks, i.e. jacks connected to hammer-butts or hammer-shanks
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10C—PIANOS, HARPSICHORDS, SPINETS OR SIMILAR STRINGED MUSICAL INSTRUMENTS WITH ONE OR MORE KEYBOARDS
- G10C3/00—Details or accessories
- G10C3/16—Actions
- G10C3/24—Repetition [tremolo] mechanisms
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10C—PIANOS, HARPSICHORDS, SPINETS OR SIMILAR STRINGED MUSICAL INSTRUMENTS WITH ONE OR MORE KEYBOARDS
- G10C3/00—Details or accessories
- G10C3/16—Actions
- G10C3/22—Actions specially adapted for grand pianos
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10C—PIANOS, HARPSICHORDS, SPINETS OR SIMILAR STRINGED MUSICAL INSTRUMENTS WITH ONE OR MORE KEYBOARDS
- G10C3/00—Details or accessories
- G10C3/16—Actions
- G10C3/166—Actions for damping the strings
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10C—PIANOS, HARPSICHORDS, SPINETS OR SIMILAR STRINGED MUSICAL INSTRUMENTS WITH ONE OR MORE KEYBOARDS
- G10C3/00—Details or accessories
- G10C3/16—Actions
- G10C3/18—Hammers
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Electrophonic Musical Instruments (AREA)
- Braking Arrangements (AREA)
Abstract
A knuckle assembly for an escapement action of a piano includes a knuckle, a jack retainer, and an adjustment means acting between the jack retainer and the knuckle for positioning the jack retainer relative to the knuckle . The knuckle is arranged for escape of the jack from engagement with a knuckle surface during depression of a piano key. The jack retainer retains the jack in an "at rest" position with the jack in engagement with the knuckle surface in opposition to force of a spring urging the jack toward the "at rest" position. A spring brake is adapted to be mounted to a repetition support of an escapement action of a piano for selective contact with a spring of the escapement action in a manner to adjust the spring force urging a jack of the escapement action toward an "at rest" position.
Description
2 1 '39 ~83 PIANO ESCAPEMENT ACTION
Bac~ ,u--d of the Invention This invention relates to pianos.
When a pianist presses upon a piano key, the motion of the key is transmitted to a hammer, which in turn strikes against a tensioned string, to produce sound. The traditional Acr ~ 1Age of levers, pivots, springs and pads that translates key motion into hammer 10 motion, allows the hammer to rebound after striking the string, and further allows for rapid repetition of notes is called a double ~ecA, - ~ action.
Figs. 1/lA through 3/3A d ~Late operation of a prior art double es~ a~ - ~ piano action 100 . For the 15 purpose of better ul~d~L~l_anding, with reference to Figs.
1 and lA, the following ~ n~ cnts remain stationary with respect to the piano during a sequence of key depression through hammer strike and return: hr ~hank flange 134, h: ~I-ank flange center pin 136, repetition support 20 center pin 112, key fulcrum 104, key pin 106, drop regulation screw 196, jack let-off button 170 and string 140 .
Still referring to Figs. 1 and lA, the prior art piano double ~c. ~ t action 100 is shown in the "at 25 rest" position. Wooden key 102, approximately 15 inches long, is mounted to pivot on felt vv~LCl, wooden fulcrum 104 and brass pin 106 extending through a vertical slot (not visible in the figures) in key 102. Repetition support 110 is mounted for rotation about metal center 30 pin (a fixed pivot point) 112. Two levers are mounted to rotate i r ~-r--n~l~ntly within the repetition assembly: an L-shaped jack 120 (also known as a "fly") mounted to rotate about center pin 121, and repetition lever 123 mounted to rotate about center pin 114. Felt hammer 130 35 is fixedly mounted at the free end of wooden shank 132 - - -~ 1 ~Y~
pin (a fixed pivot point) 112. Two levers are mounted to rotate inrlpron~ ntly within the repetition assembly: an L-shaped jack 120 (also known as a "fly") mounted to rotate about center pin 121, and repetition lever 123 5 mounted to rotate about center pin 114. Felt hammer 130 is fixedly mounted at the free end of wooden shank 132 (shown also in Figs. 7 and 7A), and wooden shank 132 is mounted to rotate about center pin 136, held stationary by flange 134. As the hammer 130 is rotated upwardly, it 10 strikes tensioned piano string 140 to create vibration and sound. Affixed to hammershank 132, between hammer 130 and center pin 136, is ~ clrin covered cylindrical kmlckle 150, engaged upon the top end surface 128 of the upper arm 122 of the jack 120.
The jack 120 is maintained in the "at rest"
position shown in Figs. 1 and lA by action of a lower end of return spring 160, which bears against the rear surface 129 of the jack, thus urging it to rotate backward (counter-clockwise in the drawings), about 20 center pin 121, until the felt regulating button 162 (mounted on the upper jack arm 128) is brought into contact with the rigid metal spoon 164 (mounted to repetition support 110). The upper end of return spring 160 biases the forward end of repetition lever 123 to 25 rotate upwardly, about center pin 114, until the pad 166, mounted at the opposite end of repetition lever 123 is brought into contact with the repetition support 110.
We ref er next to Figs . 2 and 2A ( in which the position of the action 100 in the "at rest" position of 30 Fig. lA is indicated in dashed line for ease of reference). Upon depression of the key 102 (indicated by arrow 180), repetition support 110 is moved upwardly, to rotate (arrow 182) around center pin 112, thereby actuating the various illtel ~.~yaye~ elements of the 35 repetition assembly (i.e. repetition support 110, jack 2 1 7 ~ 7 120, repetition lever 123, spring 160, regulating button 162 and spoon 164) and moving the hammer 130 towards striking ~nga~ with the piano string 140. In particular, ~ t of the jack 120 urges the knuckle 5 150 upward and to the left (in the drawings), causing the hammershank 132 to rotate about center pin 136, driving the ham~ner 130, at the free end of the hammershank, upward and to the left, toward the piano string 140 (arrow 184). During .~ ~ of the knuckle 150 upward 10 and to the left, the ~I.y~ ~ of the knuckle surface with the top end surface 128 of the jack 120 creates excessive friction, which has the recognized consequence of requiring a pianist to apply additional force in order to achieve the desired key depression. In order to 15 minimi 7e this undesirable condition, it has been known to apply lubricant to the opposed top end surface 128 and the surface of knuckle lS0, and/or to insert one or more lead counterweights 172 into the front portion of key 102. Approximately midway through full depression of the 20 key 102, the outer end of the lower arm 126 of jack 120 is brought into e..,_j t with stationary let off button 170 .
Referring now to Figs. 3 and 3A (in which the position of the action 100 in Fig. 2A is indicated in 25 dashed line for reference), as key depression continues (indicated by arrow 180), ~ of the jack lower arm 126 with stationary let off button 170 causes the jack 120 to rotate in a clockwise direction, about pin 121. This rotation causes the top end surface 128 of the 30 upper arm 122 of the jack 120 to move forward (to the right in the drawings, indicated by arrow 190), escaping from beneath the surface of the knuckle lS0. ~1~,.. / of the hammer 130 continues upward with rotation of h~ ank 132 about pin 136, with the hammer striking 35 the tensioned piano string lgO and then r~holln~ling ~ Y9/&~3 downward (arrow 192), to lodge against the opposed surface of back check 194.
When the key is released, the elements of the repetition assembly ( i . e ., repetition support 110 , jack S 120, repetition lever 123, spring 160, regulating button 162 and spoon 164) return toward the "at rest" position of Figs. 1 and lA, by the c ' ;n~cl effect of gravity and the force of spring 160 acting through repetition lever 123 against stationary drop regulation screw 196 and knuckle 150. m-~7, t of hammer 130 with back check 194 holds the hammer in a slightly elevated position, allowing the top end surface 128 of the jack 120 to move quickly, under the urging of spring 160 upon jack 120, back (left in the drawings) to its "at rest" position under knuckle 150, with the regulating button 162 engaged against spoon 164. Upon return of all of the action I s to the "at rest" position, a full keystroke is complete .
SummarY of the Invention The invention relates to a double ~' ~'7', t piano action in which key ~ ~. L rotates a jack/repetition lever assembly upward into a hammer/h .-I.ank/knuckle assembly. This assembly, in turn rotates upward propel 1 inq the hammer into a tensioned string. The jack 25 is held in its correct position beneath the knuckle by either a moveable or deformable jack retainer rather than a conventional rigid spoon. The jack retainer permits rotation of the jack within the repetition assembly during an initial portion of the action ~
30 therefore, the jack is free to follow the arcuate path of the knuckle, prior to ~cc~l t, in both the vertical and horizontal directions. This coupling motion reduces friction between the jack top surface and the knuckle lower surface.
21 9'~7~'J~
According to one aspect of the inventionL a knuckle assembly for an esu~p ~ action of a piano in~ AD5 a knuckle, a jack retainer, and an adjustment means acting between the jack retainer and the knuckle 5 for positioning the jack retainer relative to the knuckle. The knuckle assembly is mountable between a f irst end of a hammershank mounted to pivot relative to the piano and a second end of the hammershank carrying a hammer to strike a 1 ~nei onPcl string of the piano . The 10 knuckle defines a knuckle surface for e~ with a jack having a first portion extending from a pivot connection with a repetition support. The repetition support bears against a key of the piano and is mounted to pivot relative to the piano in rea~ul~se to depression 15 of the key. The knuckle is ~ .ged for escape of the jack from Dnqa~, -nt with the knuckle surface during depression of a piano key. The jack retainer retains the jack in an "at rest" position with the jack in Dn~
with the knuckle surface in opposition to force of a 20 spring urging the jack toward the "at rest" position.
According to another aspect of the invention, a pianO D~ action assembly includes a h: ~I.ank;
a knuckle assembly; a j ack having a j ack surf ace in Dnga~, ~ with a knuckle surface in an "at rest"
25 position, the jack being arranged relative to the knuckle and to a key of the piano to convey motion of the key to the knuckle, and to AieDn~6 the jack surface from the knuckle surface during depression of the key; and a spring fli~posed to urge the jack toward the "at rest"
30 position. The jack retainer position is adjustable to oppose the spring to retain the jack in the "at rest"
position, and to allow the jack, in response to depression of the key, to move in a coupled rotary motion with the knuckle assembly prior to ~1 i ~Dn~ of the 35 jack surface from the knuckle surface to allow the jack 219 ~d surface engaged with the knuckle surface to remain engaged with the knuckle surface during vc~ ~ of the knuckle .
Preferred ~ ;r ~5 of these or other aspects of 5 the invention may incc,~o~cate one or more of the following additional features. The adjustment means comprises an adju~.i t screw. The jack retainer includes a cushion surface positioned to retain the jack in the "at rest" position. The jack retainer is a 10 flexible support member extending from the knuckle. The jack retainer and the knuckle are an integral ._ _ ent.
The piano PCca, -- t action includes a repetition support lever, a relatively rigid spoon mounted for ,~ t with the repetition support lever, and a 15 regulating button mounted for ~ with the jack.
The spoon and the regulating button are ~ cposP~i at spaced apart positions in the "at rest" position of the jack. The repetition support lever has a first predetP~m~ nPd arc of travel about a f irst center point 20 and the jack retainer assembly has a second prede~P~n1 nPd arc of travel about a second center point . The f irst and second predetPrmi nPd arcs of travel are calculated relative to spacing between the f irst and second center points to avoid interference Pn~
The piano cc sca~ ~ action includes an adjustable regulating member mounted for ~ ~ between a first position allowing rotation and following of the jack, and a second position restricting ~c ~ of the jack prior to ~lispng~ ~ ~. In combination with the jack retainer, 30 a rigid spoon and jack regulating button are adjustable to maintain a predetermined spacing therebetween during initial ~ of the action, such spacing being an advantageous f eature of the invention because subsequent ad; u~ I ~ can be used to alter the f orce reguired to 35 depress a key.
_ 7 _ ~ I ~9 7 i3 The jack retainer is mounted to maintain a rolling point of ~n~A ~ of the jack surface with the knuckle surface, thereby to min;mi7e sliding friction between the jack surface and the knuckle surface during a portion of 5 the - ~ L of the action before tlic-~n~
objectives of the invention include to provide an d piano ~ccAF - L action with lower friction between j ack and knuckle surf aces to reduce unwanted noise commonly associated with these ~ ~s, and also 10 to allow reduction in size and/or number of lead weights, typically located in the front portion of the key, or to allow relocation of weights toward the center or fulcrum of the key, thereby to reduce the inertia in the key, facilitating greater key acceleration. Other objectives 15 include to provide an i uv~l piano c,crA ~ action in which the difference between force reguired for key depression and lifting force for key return is signif icantly less than present in prior art actions of similar design. Further objectives of the invention 20 include to provide an i ~_d piano ~5r~ ~ action that will permit easy manufacture of retrofit kits consisting of knuckle Ar-- ~11ec or jack retainer assemblies and relieved repetition levers for installation on most modern piano double 25 actions.
According to another aspect of the invention, a spring brake is adapted to be mounted to a repetition support of an es _~ ~ action of a piano for selective contact with a spring of the ~CCA~ t action in a 30 manner to adjust the spring force urging a jack of the c~sc~F t action toward an "at rest" position.
The esc~ t action includes a h~ ank having a f irst end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned 35 string of the piano; a repetition support bearing against - 8 - 2~9~53 a key of the piano and mounted to pivot relative to the piano in response to depression of the key; a jack having a first portion ~Yt~ndin~ from a pivot connection with the repetition support and ~i srose~l for ~ with 5 the hammershank; and a spring positioned to apply a spring force to urge the jack toward an "at rest"
position .
Preferred ' ~i ~s of the invention may include one or more of the following additional features. The 10 spring brake has an engaging section, e.g., a threaded section, for selective positioning of the spring brake relative to the repetition support.
According to another aspect of the invention, an ~C~'A, ~ action for a piano includes a h~ sl.ank, a 15 repetition support, a jack, a spring, and a spring brake mounted to the repetition support.
Preferred ~ s of this aspect of the invention may include one or more of the following additional features. A knuckle assembly is di spos~d 2 0 between the f irst end and the second end of the ~ hank. The knuckle assembly i n~ s a knuckle, a jack retainer, and an adjua; ~ means, e.g., an adjusl ~ screw, acting between the jack retainer and the knuckle for positioning the jack retainer relative to 2 5 the knuckle . The j ack def ines a j ack surf ace d i sposed for e. ,_, ~ with a knuckle surface of the knuckle.
The jack is arranged for escape of the jack surface from with the knuckle surface during depression of the key. The jack retainer position is adjustable to 30 retain the jack in the "at rest" position in opposition to force of the spring. The jack retainer includes a cushion surface positioned to retain the jack in the "at rest" position. The ~ack retainer is a flexible support member extending from the knuckle. The jack retainer and 35 the knuckle comprise an integral ~ I- ~ ~.
~i ~97~3 g According to another aspect of the invention, a piano escdp. t action assembly ; n~ ADs a h: Dl,ank having a f irst end mounted to a piano f or pivoting ~ t and a second end carrying a hammer to strike a 5 string; a knuckle assembly A;croced between the first end and the second end of the h: al,ank comprising a knuckle, a jack retainer, and an adJ~s; t means acting between the jack retainer and the knuckle for positioning the jack retainer relative to the knuckle; a ~ack having 10 a jack surface in Dnga~ - ~ with a knuckle surface of the knuckle in an "at rest" position, the jack being arranged relative to the Xnuckle and to a key of the piano to convey motion of the key to the knuckle, and to A; cDn~age the jack surface from the knuckle surface 15 during depression of the key; a spring d; RrOSDA to apply a spring force to urge the jack toward the "at rest"
position; and a spring brake for selective contact with the spring in a manner to adjust the spring force urging the jack toward the "at rest" position.
The jack retainer position is adjustable to oppose the spring to retain the jack in the "at rest" position, and allowing the jack, in ~ ea~ul.se to depression of the key, to move in a coupled rotary motion with the knuckle assembly prior to d;cPnga, t of the jack surface from 25 the knuckle surface to allow the jack surface engaged with the knuckle surface to remain engaged with the knuckle surface during ~ ~ of the knuckle.
Pref erred ~ ; ts of this aspect of the invention may include one or more of the following 30 additional features . The piano DscA, ~ ~ action assembly further includes a repetitiûn support lever, a relatively rigid spoon mounted for .~ ~ with the repetition support lever, and a regulating button mounted f or ~ ~ ~ with the j ack .
21 9~7~3 The spoon and the regulating button are d; ~posed at spaced apart positions in the "at rest" position of the jack. In an alternative ~ t, the spoon and the regulating button are in contact in the "at rest"
5 position of the jack.
The spring brake is mounted to the repetition support. The repetition support lever has a f irst predet~rm;nPd arc of travel about a first center point and the jack retainer assembly has a second predetermined 10 arc of travel about a second center point, and the first and second predet~rm; n~cl arcs of travel are calculated relative to spacing between the f irst and second center points to avoid interference ~n~A~ t.
An adjustable regulating member is mounted for 15 - ve t between a f irst position allowing rotation and following of the jack, and a second position restricting of the jack prior to d; RDn~
The jack retainer is mounted to maintain a rolling point of ~ of the jack surface with the knuckle 20 surface, thereby to m;n;m; 7~ sliding friction between the jack surface and the knuckle surface during a portion of the ~ ~ of the action before the d;~ n~, L.
Objectives of the invention include to provide an ~Ived piano es~ t action with lower friction 2 5 between j ack and knuckle surf aces to reduce unwanted noise commonly associated with these Ls, and also to allow reduction in size and/or number of lead weights, typically located in the front portion of the key, or to allow relocation of weights toward the center or fulcrum 30 of the key, thereby to reduce the inertia in the key, facilitating greater key acceleration. Other objectives include to provide an; ~,v~ piano ~SCA, 9 ~ action in which the difference between force required for key depression and lifting force for key return is 35 significantly less than present in prior art actions of similar design. Further objectives of the invention include to provide an i ~,~cd piano ~e.a~ l; action that will permit easy manufacture of retrofit kits consisting of knuckle assemblies or jack retainer 5 s~c-- ~1 ;pc and relieved repetition levers for installation on most modern piano double es~ia~
actions .
These and other f eatures and advantages of the invention will be apparent from the following description 10 of presently preferred c ' '; ~a, and from the claims.
Brief DescriDtion of the Drawinqs Figs. 1, 2 and 3 are side views of a conventional prior art piano es~ action, showing, sequentially, - ~. ~ of the action upon depression of a piano key;
15 and Figs. lA, 2A and 3A are enlarged, detail side views, taken partially in section, of the conventional prior art piano es~ t action of Figs. 1, 2 and 3, respectively, with the prior positions of the action 20 indicated in Figs. 2A and 3A by dashed line, for ease of ref erence .
Figs. 4, 5 and 6 are side views of a piano e6 ~ ~ action of the invention, showing, sequentially, - ~. t of the action upon depression of a 25 piano key; and Figs. 4A, 5A and 6A are enlarged, detail side views, taken partially in section, of the piano cs.a~ ~ action o~ Figs. 4, 5 and 6, respectively, with the prior positions of the action indicated in Figs. 5A
30 and 6A by dashed line, for ease of reference.
Figs. 7 and 7A are side and end views, respectively, of a conventional prior art hammershank.
Figs. 8 and 8A are side and end views of an of a h: al,ank of the invention;
~i ~9~8~
Figs. 9 and 9A are side and end views of another . ' 'ir ~ of a h~ ,.I.ank of the invention;
Figs. 10 and lOA are side and bottom views of yet another ' 'i- ~ of a ~ a~.ank of the invention, and 5 Fig. lOB is a side view of a pad support member of the hammershank of Fig. 10;
Fig. 11 is a side view of another: ~'~~ ~ of a h: al.ank of the invention with a slotted adjustment screw; Fig. llA is a top view of the flexible support 10 member showing a forked depression; and Fig. llB is a side view of the slotted adjustment screw;
Figs. 12 and 12A are side and end views of another _'; ~ of a h: allank of the invention;
Figs. 13 and 13A are side and end views of yet 15 another embodiment of a h: ahank of the invention;
Fig. 14 is a side view of still another ' ';~
of a h: ~I.ank of the invention; and Fig. 15 is a side view of another embodiment of a hammershank of the invention.
Fig. 16 is a side view of another: ' -'i ~ of an f.Cf ~ action with a knuckle assembly of the invention. Fig. 17 is a side view, taken partially in section, of an : - ~; r ~ of an ~CC5~, ~ action of the invention;
Fig. 18 is a similar view of another ~ of an D - , ~ action of the invention; and Fig. 19 is a similar view of yet another of an "FC~ action of the invention.
Fig. 20 is a side view, taken partially in 30 section, and Fig. 20A is a top view of a repetition lever for use in a piano ~s~ ~ L action of the invention.
Fig. 21 is a side view, taken partially in section, and Fig. 21A is a top view of a conventional prior art repetition lever.
21 997~3 Fig. 22 is a detail side view of the top end portion of an i ~ d es ~ ~ jack for use in a piano DC~ action of the invention.
Fig. 23 is a side view of a conventional prior art 5 es a~ t jack, and Fig. 23A is a detail side view of the top end portion of the conventional prior art es~ jack of Fig. 23.
Fig. 24 is a side view, taken partially in section, of another ~ of a piano D~ A, 10 action of the invention, while Fig. 24A is a plan view of a cam e~ployed in the embodiment of the piano D.:CA, action of the invention of Fig. 24.
Fig. 25 is a side view of a piano e~
action of the invention.
Fig. 26 is a side view of a piano es__~ L
action of the invention, similar to that of Fig. 1, with a spring brake, while Fig. 26A shows .. ~ ~ of the action upon depression of a piano key.
Fig. 26B is an enlarged view of section 26B of 20 Fig. 26.
Fig. 27 is a side view of a piano DscA, action of the invention, as shown in Fig. 4, with a spring brake, while Figs. 27A and 27B show .~ ~ of the action upon depression of a piano key.
Descril~tion of the Preferred Embodiments An; ~v_d piano DScA~ ~ action 200 of the invention, and its operation, will now be described with reference to the drawings, in which, for ~u~oses of clarity and ease of understanding, elements having 30 structure and function as in the prior art action 100 described above will be identified using the same reference numerals.
In the operation of the; ~ d piano ~es-_~ t action 200 of the invention, the jack 120 is free to 35 follow the arcuate motion of the knuckle 150, with the ~1 9~7~3 top end gurface 128 of the jack maintaining a rolling point of contact with knuckle 150 until the lower arm 126 of the jack contacts the stationary let off button 170.
Referring first to Figs. 4 and 4A, an i vv~d 5 piano double es~ action 200 of the invention is shown in "at rest" position. As in the operation of a conventional prior art action (described above), when key 102 is depressed by a pianist (indicated by arrow 180), the key pivots on fulcrum 104 and key center pin 106.
10 Il.~ ~ of the key moves the repetition support 110, which in turn pivotally :,u~o. ~a L-shaped jacX 120 and repetition lever 202, and the hammer 130 at the end of h: shank 132 is moved to strike string 140 by rotation of the h: ~I.ank about pin 136 in stationary flange 134. Rnuckle 150 ':UIJ~JVL~a the hammershank 132 by engagement upon the top end surface 128 of the upper arm 122 of jack 120. The "at rest" position of jack 120 is maintained by a return spring 160, which acts between jack 120 and the u.,derau.race of repetition lever 202.
In the i v~,~d piano double e~ action 200 of the invention, a jack retainer assembly 204 consists of a jack retainer cushion 206 positioned below the knuckle 150 by rigid support member 208 extending from hammershank 132. The upper arm 122 of jack 120 is urged against the face surface 210 of jack retainer cushion 206 by action of spring 160 (as indicated by arrow 212). In this position, with the ~ack 120 held in the "at rest"
position engaged upon retainer cushion 206, the regulating button 162 is held in an "at rest" position 30 spaced from ~ng~r, t with spoon 164. As a result, biasing force of spring 160 is redistributed from urging the regulating button 162 against the spoon 164 towards urging the upper arm 128 of the jack 120 against the retainer cushion 206 (arrow 212) which, in turn, applies 35 a slight lifting force (arrow 214) to h: ,I.ank 132 ~1 q~7~3 carrying hammer 130. This lifting force, CC,~ an~ly applied to the hammer, reduces the inertia that must be G.~ by a pianist applying his or her f inger to set the hammer 130 into motion.
We refer next to Figs. 5 and 5A (in which the position of the action 200 in the "at rest" position of Fig. 4A is indicated in dashed line for ease of reference). Upon depression of the key 102 (indicated by arrow 180), the repetition support 110 is moved upwardly, 10 to rotate (arrow 182) the repetition assembly (i.e., repetition support 110, jack 120, spring 160, regulating button 162, spoon 164 and repetition lever 202) about stationary center pin 112, toward string 140. The top end surface 128 of jack 120 presses knuckle 150 upward, 15 to urge the h~ ank 132 and hammer 130 upward toward string 140 (arrow 184). In Figs. 5 and 5A, the lower arm 126 of jack 120 has just come into contact with the let-off button 170. As repetition assembly (i.e., repetition support 110, jack 120, spring 160, regulating 20 button 162, spoon 164 and repetition lever 202) continues to rotate upward from the "at rest" position, the top end surface 128 of jack upper arm 122 follows knuckle 150 upward and to the left (arrow 216), maintaining a rolling point of contact between jack top end surface 128 and 25 knuckle 150. The clearance provided between regulating button 162 and spoon 164 in the "at rest" position leaves the jack upper arm 122 ~ree to ~ove to the left (in the orientation of the drawings) until either the regulating button 162 contacts spoon 164, or jack lower arm 126 30 contacts let-off button 170, whichever occurs first (d~p~n~iin~ upon adjustment, as discussed below).
Finally, referring to Figs. 6 and 6A (in which the position of the i u~/ed action 200 in Fig. 5A is indicated in dashed line for reference), as key 35 depression continues (indicated by arrow 180), jack lower 2i ~7~J
arm 126 presses against let off button 170, jack 120 is forced to rotate in a clockwise direction, about pin 121, thereby causing the top end surface 128 of the jack upper arm 122 to escape (arrow 218) from under knuckle 150.
5 The hammershank 132, carrying hammer 130, is then free to rebound (arrow 220), after the hammer strikes the tensioned piano string 140, and to fall against back check 194.
When the key 102 is released, the; v~_d piano 10 ~qc~L ~ action 200 of the invention returns to the "at rest" position shown in Figs. 4 and 4A, with regulating button 162 spaced from spoon 164 and the upper arm 122 of jack 120 urged (arrow 212) against retainer cushion 206 by return spring 160.
Referring now to Figs. 8 through 16, we will now describe preferred ~ ;r ~S of the invention, in which the jack 120 is held in its "at rest" position by engagement of the jack upper arm 122 against the jack retainer assembly 204, rather than by c.ng:~3 L of the 20 regulating button 162 against spoon 164.
In the ~ t of Figs. 8 and 8A, the jack retainer assembly 204 is shown in its simplest form, with a generally rect~n~l~r jack retainer cushion 206 held in place below the knuckle 150 by rigid support member 208 25 attached directly to h~ sllank 132.
In the: ~ o ~ of Figs . 9 and 9A, a retainer cushion 230 is affixed to adjustable support member 232.
An adjustment screw 234 threaded through h: sl.ank 236 has a head engaged with a pad 238 contacting support 30 member 232. Rotation of screw 234 acts to adjust the position of the retainer cushion 230.
Referring to Figs. 10, lOA and lOB, in; v~,~d ~I-ank 240, e.g. for use in the: '~'i- ~ of the v~_d piano es-ia~ t action 200 of Figs. 6 and 6A, 35 flexible support member 242 has a ~ev-dr~ular end portion 21 q~
244 that is secured in r~L~. J lA~ recess 246 defined by hammershank 240 by a fastener 248, e.g. a pin or screw.
In the: ' ';~ ~ of Figs. 11 and llA, an adjustable support member 2S0 is m--h;n~ to include a 5 fork-like depression 252 at the point of adj~ . The fork 252 is positioned within a slot 254 of collared zlju~l ~ t screw 256, permitting both upward and downward ~lju~l - t. In Fig. llB details of the construction of the adjuat t screw 256 are shown.
In the ' ~ L of Figs. 12 and 12A, a jack retainer cushion 260 is affixed to a relatively more r-lle~hle support member 262 formed, e.g., of soft metal, plastic or similar elastically deformable material. The flexible support member 262 is bent to reposition 15 retainer cushion 260 along arc 264, which in turn allows for precise location of jack 120 relative to knuckle 150.
In the: ' :'i-- L of Figs. 13 and 13A, a jack retainer cushion 270 is affixed to a wooden button 272.
The cushion and button are f itted into a recess 274 20 within a wooden support member 276 attached to hammershank 278, and held in place by a loop of elastic material 280 that fits within a groove 282 defined in support member 276. The position of cushion assembly 270, 272 can be f inely regulated by inserting or removing 25 shims or spacers between button 272 and support member 276 .
In the: '; t of Fig. 14, an extra layer 284, e.g. of ~ ;n or similar material, is affixed to knuckle 150, with an end face 286 of layer 284 acting as 30 the support member for a jack retainer cushion 288.
In the ~ ;- L of Fig. 15, a screw 290 extends through a h: ~I,ank 292. A jack retainer cushion 294 is affixed to the portion of screw 290 that extends below knuckle 150. The screw 290 is inserted into the 35 h: ~llank 292 at an angle, so that raising and lowering 7 ~ 3 the screw 290 adjusts the position of jack retainer cushion 294 relative to knuckle 150.
In the ~ of Fig. 16, a knuckle assembly 330 consisting of an integral knuckle and retainer 5 ;n~ c a body 332 formed, e.g., of wood, defining a knuckle surface 334 having a cover 336 formed, e.g., of b~ ;n. A support member 338 formed, e.g., of wood or plastic, includes a retainer cushion 340, e.g., a felt pad. An adju~l t screw 342 in threaded ~ with 10 member 338 and bearing against the opposed surface 343 of body 332 is used to adjust the position of retainer cushion 340 relative to knuckle body 332. The cantilevered support member 338 is flexible enough to allow a~jua~ t of the position of retainer cushion 340 15 on its free end, while maintaining enough rigidity to hold jack 120 in its "at rest" position (the required holding force being in the range of about 5 to 20 grams).
A~lju~l L of the position of retainer cushion 340 is made, e.g., to ~ ~ te for ~ ssion of the retainer 20 cushion over time and to align the retainer cushion during assembly of the ~C~'A, ~ action. Rnuckle assembly 330 is attached to ~ ~I.ank 132 by, e.g., glue .
In the: ' --;r ~ of Fig. 26, a conventional grand 25 piano action of Fig. 1 is modif ied to include a spring brake 360 in t.}~- aad~d ~ with repetition support 110. When jack 120 is rotated forward during key depression (Fig. 26A), lower arm 362 of spring 160 is in contact with a ledge 364 of jack 120 but is not in 30 contact with spring brake 360. When the key is depressed, spring 160 thus acts to bias jack 120 toward returning to its "at rest" position of Fig. 26.
After release of key 102, and during the return of jack 120 to its "at rest" position under the applied load 35 of spring 160, spring brake 360 contacts lower arm 362, ~i ~i7~
causing lower arm 362 to lose contact with jack 120 before regulating button 162 contacts spoon 164. Contact of lower spring arm 362 with spring brake 360 before regulating button 162 contacts spoon 164 acts to 5 decelerate jack 120, thus helping to -~u~ess noise that may otherwise result from the contact of regulating button 162 with spoon 164 under spring load.
As shown in Fig. 26B, spring brake 360 has a forked end 364 for engaging spring 160. The threaded 10 ~ t of spring brake 360 with repetition support 110 allows the spring force of return spring 160 acting on jack 120 to be adjusted to selectively act on the rotational movement of jack 120 only during a desired portion of the jack's rotation.
Spring brake 360 can also be used with other occAr~ t actions. For example, referring to Figs. 27-27B, spring brake 360 is shown in.vL~vlc.ted into the OCCA, ~1 ~ action of Fig. 4. With jack 120 in its "at rest" position (Fig. 27), lower arm 362 of spring 160 is 20 in contact with a ledge 366 of jack 120. At half key depression (Fig. 27A), spring brake 360 contacts lower spring arm 362 causing lower spring arm 362 to lose contact with jack 120. At full key depression (Fig.
27B), lower spring arm 362 is again in contact with jack 25 120 and acts to return jack 120 to its "at rest" position of Fig. 27. As in the conventional action described above, the loss of contact of lower spring arm 362 with jack 120 causes jack 120 to decelerate prior to contact of regulating button 162 with spoon 164 in the half key 30 depression position of Fig. 27A thus helping with noise ~U}~L Pssion .
Other ' ~ ts of the invention are within the following claims. For example, the relatively low compliance regulating button 162 and/or rigid spoon 164 35 of prior art ~C~'A, ~ actions may be replaced with higher compliance ~ ~s to allow jack 120 to follow the arcuate motion of knuckle 150.
Also, referring to Fig. 17, a high compliance button 162 ' ~.asses against spoon 164 ' allowing the 5 jack 120 to follow the knuckle 150; in Pig. 18, rigid spoon 164 is replaced with compliant spring member 296;
and in Fig. 19, a spring member 298 extends through the repetition lever 300 and engages against the rear surface of knuckle 150, again leaving the jack 120 free to follow 10 knuckle 150.
Also, referring to Figs. 20 and 20A, an; vv~:d repetition lever 310 configured for use with the; .u~,~d h~ ank of Figs. 8 through 16 has a slot d;r- -;nn 312 that is extended and angled or stepped. This is in 15 comparison to the ~OLL~ IA;n~ slot dimension 314 of a conventional prior art repetition lever 316 (shown in Figs. 21 and 21A).
Referring now to Fig. 22, in a jack 120' for use in the; v~_d action of the invention, the front upper 20 corner of the top end surface 128' portion may have an enlarged radius 320 to allow jack top surface 128' to roll against knuckle 150. In ~ v~-~L~=~L~ referring to Figs. 23 and 23A, top surface 128 of conventional jack 120 has a relatively smaller radius only at rear upper 25 corner 322, to ease the return of upper arm 122 under knuckle 150 when the key is released.
Referring to Figs. 24 and 24A, a oval or elliptical cam 800, mounted between rigid supports 801 (only one is shown) on repetition support 110 is 30 rotatable around pivot axis 802 to vary the space between regulating button 162 and the surface of cam 800, thus adjusting the point during the keystroke at which ~n~J~, ~ between opposed surf aces of the j ack and knuckle is initiated. If the space is larger, jack 120 35 will travel with knuckle 150, e.g., as described in Figs.
~ j y~7~3 4/4A through 6/6A. If the space is reduced by rotating cam 800 into position 804 (shown in dashed lines in Fig.
24), the action will function in a more conventional manner. Rotation (arrow 806) of the cam can be affected, S e . g . by a pedal, f inger lever or similar device connected to cam 800 by a flexible or rigid lever linkage.
Similarly, mf '-n; for adjusting the location of spoon 164 may include , e . g ., a rigid bar that moves (left to right in the orientation of the figures), lO activated by a f lexible or rigid lever linkage .
Finally, referring to Fig. 25, where the repetition support lever has a first prede~Drminod arc of travel, r1, about a first center point 112 and the jack retainer assembly has a second predetermined arc of 15 travel, r2, about a second center point 136, the first and second predet~m; n~ arcs of travel are calculated relative to the length of a line, AB, between the first and second center points according to the equation:
rl + r2 < AB
(where A = repetition support pivot, B = hr ~I-dllk pivot, r1 = radius of repetition lever cut out arc, and r2 = radius of h~ ank tab arc) to avoid interference ,. t and to ~--Y;m; 7e performance aspects of the ; _ Ove;l action.
What is claimed is:
Bac~ ,u--d of the Invention This invention relates to pianos.
When a pianist presses upon a piano key, the motion of the key is transmitted to a hammer, which in turn strikes against a tensioned string, to produce sound. The traditional Acr ~ 1Age of levers, pivots, springs and pads that translates key motion into hammer 10 motion, allows the hammer to rebound after striking the string, and further allows for rapid repetition of notes is called a double ~ecA, - ~ action.
Figs. 1/lA through 3/3A d ~Late operation of a prior art double es~ a~ - ~ piano action 100 . For the 15 purpose of better ul~d~L~l_anding, with reference to Figs.
1 and lA, the following ~ n~ cnts remain stationary with respect to the piano during a sequence of key depression through hammer strike and return: hr ~hank flange 134, h: ~I-ank flange center pin 136, repetition support 20 center pin 112, key fulcrum 104, key pin 106, drop regulation screw 196, jack let-off button 170 and string 140 .
Still referring to Figs. 1 and lA, the prior art piano double ~c. ~ t action 100 is shown in the "at 25 rest" position. Wooden key 102, approximately 15 inches long, is mounted to pivot on felt vv~LCl, wooden fulcrum 104 and brass pin 106 extending through a vertical slot (not visible in the figures) in key 102. Repetition support 110 is mounted for rotation about metal center 30 pin (a fixed pivot point) 112. Two levers are mounted to rotate i r ~-r--n~l~ntly within the repetition assembly: an L-shaped jack 120 (also known as a "fly") mounted to rotate about center pin 121, and repetition lever 123 mounted to rotate about center pin 114. Felt hammer 130 35 is fixedly mounted at the free end of wooden shank 132 - - -~ 1 ~Y~
pin (a fixed pivot point) 112. Two levers are mounted to rotate inrlpron~ ntly within the repetition assembly: an L-shaped jack 120 (also known as a "fly") mounted to rotate about center pin 121, and repetition lever 123 5 mounted to rotate about center pin 114. Felt hammer 130 is fixedly mounted at the free end of wooden shank 132 (shown also in Figs. 7 and 7A), and wooden shank 132 is mounted to rotate about center pin 136, held stationary by flange 134. As the hammer 130 is rotated upwardly, it 10 strikes tensioned piano string 140 to create vibration and sound. Affixed to hammershank 132, between hammer 130 and center pin 136, is ~ clrin covered cylindrical kmlckle 150, engaged upon the top end surface 128 of the upper arm 122 of the jack 120.
The jack 120 is maintained in the "at rest"
position shown in Figs. 1 and lA by action of a lower end of return spring 160, which bears against the rear surface 129 of the jack, thus urging it to rotate backward (counter-clockwise in the drawings), about 20 center pin 121, until the felt regulating button 162 (mounted on the upper jack arm 128) is brought into contact with the rigid metal spoon 164 (mounted to repetition support 110). The upper end of return spring 160 biases the forward end of repetition lever 123 to 25 rotate upwardly, about center pin 114, until the pad 166, mounted at the opposite end of repetition lever 123 is brought into contact with the repetition support 110.
We ref er next to Figs . 2 and 2A ( in which the position of the action 100 in the "at rest" position of 30 Fig. lA is indicated in dashed line for ease of reference). Upon depression of the key 102 (indicated by arrow 180), repetition support 110 is moved upwardly, to rotate (arrow 182) around center pin 112, thereby actuating the various illtel ~.~yaye~ elements of the 35 repetition assembly (i.e. repetition support 110, jack 2 1 7 ~ 7 120, repetition lever 123, spring 160, regulating button 162 and spoon 164) and moving the hammer 130 towards striking ~nga~ with the piano string 140. In particular, ~ t of the jack 120 urges the knuckle 5 150 upward and to the left (in the drawings), causing the hammershank 132 to rotate about center pin 136, driving the ham~ner 130, at the free end of the hammershank, upward and to the left, toward the piano string 140 (arrow 184). During .~ ~ of the knuckle 150 upward 10 and to the left, the ~I.y~ ~ of the knuckle surface with the top end surface 128 of the jack 120 creates excessive friction, which has the recognized consequence of requiring a pianist to apply additional force in order to achieve the desired key depression. In order to 15 minimi 7e this undesirable condition, it has been known to apply lubricant to the opposed top end surface 128 and the surface of knuckle lS0, and/or to insert one or more lead counterweights 172 into the front portion of key 102. Approximately midway through full depression of the 20 key 102, the outer end of the lower arm 126 of jack 120 is brought into e..,_j t with stationary let off button 170 .
Referring now to Figs. 3 and 3A (in which the position of the action 100 in Fig. 2A is indicated in 25 dashed line for reference), as key depression continues (indicated by arrow 180), ~ of the jack lower arm 126 with stationary let off button 170 causes the jack 120 to rotate in a clockwise direction, about pin 121. This rotation causes the top end surface 128 of the 30 upper arm 122 of the jack 120 to move forward (to the right in the drawings, indicated by arrow 190), escaping from beneath the surface of the knuckle lS0. ~1~,.. / of the hammer 130 continues upward with rotation of h~ ank 132 about pin 136, with the hammer striking 35 the tensioned piano string lgO and then r~holln~ling ~ Y9/&~3 downward (arrow 192), to lodge against the opposed surface of back check 194.
When the key is released, the elements of the repetition assembly ( i . e ., repetition support 110 , jack S 120, repetition lever 123, spring 160, regulating button 162 and spoon 164) return toward the "at rest" position of Figs. 1 and lA, by the c ' ;n~cl effect of gravity and the force of spring 160 acting through repetition lever 123 against stationary drop regulation screw 196 and knuckle 150. m-~7, t of hammer 130 with back check 194 holds the hammer in a slightly elevated position, allowing the top end surface 128 of the jack 120 to move quickly, under the urging of spring 160 upon jack 120, back (left in the drawings) to its "at rest" position under knuckle 150, with the regulating button 162 engaged against spoon 164. Upon return of all of the action I s to the "at rest" position, a full keystroke is complete .
SummarY of the Invention The invention relates to a double ~' ~'7', t piano action in which key ~ ~. L rotates a jack/repetition lever assembly upward into a hammer/h .-I.ank/knuckle assembly. This assembly, in turn rotates upward propel 1 inq the hammer into a tensioned string. The jack 25 is held in its correct position beneath the knuckle by either a moveable or deformable jack retainer rather than a conventional rigid spoon. The jack retainer permits rotation of the jack within the repetition assembly during an initial portion of the action ~
30 therefore, the jack is free to follow the arcuate path of the knuckle, prior to ~cc~l t, in both the vertical and horizontal directions. This coupling motion reduces friction between the jack top surface and the knuckle lower surface.
21 9'~7~'J~
According to one aspect of the inventionL a knuckle assembly for an esu~p ~ action of a piano in~ AD5 a knuckle, a jack retainer, and an adjustment means acting between the jack retainer and the knuckle 5 for positioning the jack retainer relative to the knuckle. The knuckle assembly is mountable between a f irst end of a hammershank mounted to pivot relative to the piano and a second end of the hammershank carrying a hammer to strike a 1 ~nei onPcl string of the piano . The 10 knuckle defines a knuckle surface for e~ with a jack having a first portion extending from a pivot connection with a repetition support. The repetition support bears against a key of the piano and is mounted to pivot relative to the piano in rea~ul~se to depression 15 of the key. The knuckle is ~ .ged for escape of the jack from Dnqa~, -nt with the knuckle surface during depression of a piano key. The jack retainer retains the jack in an "at rest" position with the jack in Dn~
with the knuckle surface in opposition to force of a 20 spring urging the jack toward the "at rest" position.
According to another aspect of the invention, a pianO D~ action assembly includes a h: ~I.ank;
a knuckle assembly; a j ack having a j ack surf ace in Dnga~, ~ with a knuckle surface in an "at rest"
25 position, the jack being arranged relative to the knuckle and to a key of the piano to convey motion of the key to the knuckle, and to AieDn~6 the jack surface from the knuckle surface during depression of the key; and a spring fli~posed to urge the jack toward the "at rest"
30 position. The jack retainer position is adjustable to oppose the spring to retain the jack in the "at rest"
position, and to allow the jack, in response to depression of the key, to move in a coupled rotary motion with the knuckle assembly prior to ~1 i ~Dn~ of the 35 jack surface from the knuckle surface to allow the jack 219 ~d surface engaged with the knuckle surface to remain engaged with the knuckle surface during vc~ ~ of the knuckle .
Preferred ~ ;r ~5 of these or other aspects of 5 the invention may incc,~o~cate one or more of the following additional features. The adjustment means comprises an adju~.i t screw. The jack retainer includes a cushion surface positioned to retain the jack in the "at rest" position. The jack retainer is a 10 flexible support member extending from the knuckle. The jack retainer and the knuckle are an integral ._ _ ent.
The piano PCca, -- t action includes a repetition support lever, a relatively rigid spoon mounted for ,~ t with the repetition support lever, and a 15 regulating button mounted for ~ with the jack.
The spoon and the regulating button are ~ cposP~i at spaced apart positions in the "at rest" position of the jack. The repetition support lever has a first predetP~m~ nPd arc of travel about a f irst center point 20 and the jack retainer assembly has a second prede~P~n1 nPd arc of travel about a second center point . The f irst and second predetPrmi nPd arcs of travel are calculated relative to spacing between the f irst and second center points to avoid interference Pn~
The piano cc sca~ ~ action includes an adjustable regulating member mounted for ~ ~ between a first position allowing rotation and following of the jack, and a second position restricting ~c ~ of the jack prior to ~lispng~ ~ ~. In combination with the jack retainer, 30 a rigid spoon and jack regulating button are adjustable to maintain a predetermined spacing therebetween during initial ~ of the action, such spacing being an advantageous f eature of the invention because subsequent ad; u~ I ~ can be used to alter the f orce reguired to 35 depress a key.
_ 7 _ ~ I ~9 7 i3 The jack retainer is mounted to maintain a rolling point of ~n~A ~ of the jack surface with the knuckle surface, thereby to min;mi7e sliding friction between the jack surface and the knuckle surface during a portion of 5 the - ~ L of the action before tlic-~n~
objectives of the invention include to provide an d piano ~ccAF - L action with lower friction between j ack and knuckle surf aces to reduce unwanted noise commonly associated with these ~ ~s, and also 10 to allow reduction in size and/or number of lead weights, typically located in the front portion of the key, or to allow relocation of weights toward the center or fulcrum of the key, thereby to reduce the inertia in the key, facilitating greater key acceleration. Other objectives 15 include to provide an i uv~l piano c,crA ~ action in which the difference between force reguired for key depression and lifting force for key return is signif icantly less than present in prior art actions of similar design. Further objectives of the invention 20 include to provide an i ~_d piano ~5r~ ~ action that will permit easy manufacture of retrofit kits consisting of knuckle Ar-- ~11ec or jack retainer assemblies and relieved repetition levers for installation on most modern piano double 25 actions.
According to another aspect of the invention, a spring brake is adapted to be mounted to a repetition support of an es _~ ~ action of a piano for selective contact with a spring of the ~CCA~ t action in a 30 manner to adjust the spring force urging a jack of the c~sc~F t action toward an "at rest" position.
The esc~ t action includes a h~ ank having a f irst end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned 35 string of the piano; a repetition support bearing against - 8 - 2~9~53 a key of the piano and mounted to pivot relative to the piano in response to depression of the key; a jack having a first portion ~Yt~ndin~ from a pivot connection with the repetition support and ~i srose~l for ~ with 5 the hammershank; and a spring positioned to apply a spring force to urge the jack toward an "at rest"
position .
Preferred ' ~i ~s of the invention may include one or more of the following additional features. The 10 spring brake has an engaging section, e.g., a threaded section, for selective positioning of the spring brake relative to the repetition support.
According to another aspect of the invention, an ~C~'A, ~ action for a piano includes a h~ sl.ank, a 15 repetition support, a jack, a spring, and a spring brake mounted to the repetition support.
Preferred ~ s of this aspect of the invention may include one or more of the following additional features. A knuckle assembly is di spos~d 2 0 between the f irst end and the second end of the ~ hank. The knuckle assembly i n~ s a knuckle, a jack retainer, and an adjua; ~ means, e.g., an adjusl ~ screw, acting between the jack retainer and the knuckle for positioning the jack retainer relative to 2 5 the knuckle . The j ack def ines a j ack surf ace d i sposed for e. ,_, ~ with a knuckle surface of the knuckle.
The jack is arranged for escape of the jack surface from with the knuckle surface during depression of the key. The jack retainer position is adjustable to 30 retain the jack in the "at rest" position in opposition to force of the spring. The jack retainer includes a cushion surface positioned to retain the jack in the "at rest" position. The ~ack retainer is a flexible support member extending from the knuckle. The jack retainer and 35 the knuckle comprise an integral ~ I- ~ ~.
~i ~97~3 g According to another aspect of the invention, a piano escdp. t action assembly ; n~ ADs a h: Dl,ank having a f irst end mounted to a piano f or pivoting ~ t and a second end carrying a hammer to strike a 5 string; a knuckle assembly A;croced between the first end and the second end of the h: al,ank comprising a knuckle, a jack retainer, and an adJ~s; t means acting between the jack retainer and the knuckle for positioning the jack retainer relative to the knuckle; a ~ack having 10 a jack surface in Dnga~ - ~ with a knuckle surface of the knuckle in an "at rest" position, the jack being arranged relative to the Xnuckle and to a key of the piano to convey motion of the key to the knuckle, and to A; cDn~age the jack surface from the knuckle surface 15 during depression of the key; a spring d; RrOSDA to apply a spring force to urge the jack toward the "at rest"
position; and a spring brake for selective contact with the spring in a manner to adjust the spring force urging the jack toward the "at rest" position.
The jack retainer position is adjustable to oppose the spring to retain the jack in the "at rest" position, and allowing the jack, in ~ ea~ul.se to depression of the key, to move in a coupled rotary motion with the knuckle assembly prior to d;cPnga, t of the jack surface from 25 the knuckle surface to allow the jack surface engaged with the knuckle surface to remain engaged with the knuckle surface during ~ ~ of the knuckle.
Pref erred ~ ; ts of this aspect of the invention may include one or more of the following 30 additional features . The piano DscA, ~ ~ action assembly further includes a repetitiûn support lever, a relatively rigid spoon mounted for .~ ~ with the repetition support lever, and a regulating button mounted f or ~ ~ ~ with the j ack .
21 9~7~3 The spoon and the regulating button are d; ~posed at spaced apart positions in the "at rest" position of the jack. In an alternative ~ t, the spoon and the regulating button are in contact in the "at rest"
5 position of the jack.
The spring brake is mounted to the repetition support. The repetition support lever has a f irst predet~rm;nPd arc of travel about a first center point and the jack retainer assembly has a second predetermined 10 arc of travel about a second center point, and the first and second predet~rm; n~cl arcs of travel are calculated relative to spacing between the f irst and second center points to avoid interference ~n~A~ t.
An adjustable regulating member is mounted for 15 - ve t between a f irst position allowing rotation and following of the jack, and a second position restricting of the jack prior to d; RDn~
The jack retainer is mounted to maintain a rolling point of ~ of the jack surface with the knuckle 20 surface, thereby to m;n;m; 7~ sliding friction between the jack surface and the knuckle surface during a portion of the ~ ~ of the action before the d;~ n~, L.
Objectives of the invention include to provide an ~Ived piano es~ t action with lower friction 2 5 between j ack and knuckle surf aces to reduce unwanted noise commonly associated with these Ls, and also to allow reduction in size and/or number of lead weights, typically located in the front portion of the key, or to allow relocation of weights toward the center or fulcrum 30 of the key, thereby to reduce the inertia in the key, facilitating greater key acceleration. Other objectives include to provide an; ~,v~ piano ~SCA, 9 ~ action in which the difference between force required for key depression and lifting force for key return is 35 significantly less than present in prior art actions of similar design. Further objectives of the invention include to provide an i ~,~cd piano ~e.a~ l; action that will permit easy manufacture of retrofit kits consisting of knuckle assemblies or jack retainer 5 s~c-- ~1 ;pc and relieved repetition levers for installation on most modern piano double es~ia~
actions .
These and other f eatures and advantages of the invention will be apparent from the following description 10 of presently preferred c ' '; ~a, and from the claims.
Brief DescriDtion of the Drawinqs Figs. 1, 2 and 3 are side views of a conventional prior art piano es~ action, showing, sequentially, - ~. ~ of the action upon depression of a piano key;
15 and Figs. lA, 2A and 3A are enlarged, detail side views, taken partially in section, of the conventional prior art piano es~ t action of Figs. 1, 2 and 3, respectively, with the prior positions of the action 20 indicated in Figs. 2A and 3A by dashed line, for ease of ref erence .
Figs. 4, 5 and 6 are side views of a piano e6 ~ ~ action of the invention, showing, sequentially, - ~. t of the action upon depression of a 25 piano key; and Figs. 4A, 5A and 6A are enlarged, detail side views, taken partially in section, of the piano cs.a~ ~ action o~ Figs. 4, 5 and 6, respectively, with the prior positions of the action indicated in Figs. 5A
30 and 6A by dashed line, for ease of reference.
Figs. 7 and 7A are side and end views, respectively, of a conventional prior art hammershank.
Figs. 8 and 8A are side and end views of an of a h: al,ank of the invention;
~i ~9~8~
Figs. 9 and 9A are side and end views of another . ' 'ir ~ of a h~ ,.I.ank of the invention;
Figs. 10 and lOA are side and bottom views of yet another ' 'i- ~ of a ~ a~.ank of the invention, and 5 Fig. lOB is a side view of a pad support member of the hammershank of Fig. 10;
Fig. 11 is a side view of another: ~'~~ ~ of a h: al.ank of the invention with a slotted adjustment screw; Fig. llA is a top view of the flexible support 10 member showing a forked depression; and Fig. llB is a side view of the slotted adjustment screw;
Figs. 12 and 12A are side and end views of another _'; ~ of a h: allank of the invention;
Figs. 13 and 13A are side and end views of yet 15 another embodiment of a h: ahank of the invention;
Fig. 14 is a side view of still another ' ';~
of a h: ~I.ank of the invention; and Fig. 15 is a side view of another embodiment of a hammershank of the invention.
Fig. 16 is a side view of another: ' -'i ~ of an f.Cf ~ action with a knuckle assembly of the invention. Fig. 17 is a side view, taken partially in section, of an : - ~; r ~ of an ~CC5~, ~ action of the invention;
Fig. 18 is a similar view of another ~ of an D - , ~ action of the invention; and Fig. 19 is a similar view of yet another of an "FC~ action of the invention.
Fig. 20 is a side view, taken partially in 30 section, and Fig. 20A is a top view of a repetition lever for use in a piano ~s~ ~ L action of the invention.
Fig. 21 is a side view, taken partially in section, and Fig. 21A is a top view of a conventional prior art repetition lever.
21 997~3 Fig. 22 is a detail side view of the top end portion of an i ~ d es ~ ~ jack for use in a piano DC~ action of the invention.
Fig. 23 is a side view of a conventional prior art 5 es a~ t jack, and Fig. 23A is a detail side view of the top end portion of the conventional prior art es~ jack of Fig. 23.
Fig. 24 is a side view, taken partially in section, of another ~ of a piano D~ A, 10 action of the invention, while Fig. 24A is a plan view of a cam e~ployed in the embodiment of the piano D.:CA, action of the invention of Fig. 24.
Fig. 25 is a side view of a piano e~
action of the invention.
Fig. 26 is a side view of a piano es__~ L
action of the invention, similar to that of Fig. 1, with a spring brake, while Fig. 26A shows .. ~ ~ of the action upon depression of a piano key.
Fig. 26B is an enlarged view of section 26B of 20 Fig. 26.
Fig. 27 is a side view of a piano DscA, action of the invention, as shown in Fig. 4, with a spring brake, while Figs. 27A and 27B show .~ ~ of the action upon depression of a piano key.
Descril~tion of the Preferred Embodiments An; ~v_d piano DScA~ ~ action 200 of the invention, and its operation, will now be described with reference to the drawings, in which, for ~u~oses of clarity and ease of understanding, elements having 30 structure and function as in the prior art action 100 described above will be identified using the same reference numerals.
In the operation of the; ~ d piano ~es-_~ t action 200 of the invention, the jack 120 is free to 35 follow the arcuate motion of the knuckle 150, with the ~1 9~7~3 top end gurface 128 of the jack maintaining a rolling point of contact with knuckle 150 until the lower arm 126 of the jack contacts the stationary let off button 170.
Referring first to Figs. 4 and 4A, an i vv~d 5 piano double es~ action 200 of the invention is shown in "at rest" position. As in the operation of a conventional prior art action (described above), when key 102 is depressed by a pianist (indicated by arrow 180), the key pivots on fulcrum 104 and key center pin 106.
10 Il.~ ~ of the key moves the repetition support 110, which in turn pivotally :,u~o. ~a L-shaped jacX 120 and repetition lever 202, and the hammer 130 at the end of h: shank 132 is moved to strike string 140 by rotation of the h: ~I.ank about pin 136 in stationary flange 134. Rnuckle 150 ':UIJ~JVL~a the hammershank 132 by engagement upon the top end surface 128 of the upper arm 122 of jack 120. The "at rest" position of jack 120 is maintained by a return spring 160, which acts between jack 120 and the u.,derau.race of repetition lever 202.
In the i v~,~d piano double e~ action 200 of the invention, a jack retainer assembly 204 consists of a jack retainer cushion 206 positioned below the knuckle 150 by rigid support member 208 extending from hammershank 132. The upper arm 122 of jack 120 is urged against the face surface 210 of jack retainer cushion 206 by action of spring 160 (as indicated by arrow 212). In this position, with the ~ack 120 held in the "at rest"
position engaged upon retainer cushion 206, the regulating button 162 is held in an "at rest" position 30 spaced from ~ng~r, t with spoon 164. As a result, biasing force of spring 160 is redistributed from urging the regulating button 162 against the spoon 164 towards urging the upper arm 128 of the jack 120 against the retainer cushion 206 (arrow 212) which, in turn, applies 35 a slight lifting force (arrow 214) to h: ,I.ank 132 ~1 q~7~3 carrying hammer 130. This lifting force, CC,~ an~ly applied to the hammer, reduces the inertia that must be G.~ by a pianist applying his or her f inger to set the hammer 130 into motion.
We refer next to Figs. 5 and 5A (in which the position of the action 200 in the "at rest" position of Fig. 4A is indicated in dashed line for ease of reference). Upon depression of the key 102 (indicated by arrow 180), the repetition support 110 is moved upwardly, 10 to rotate (arrow 182) the repetition assembly (i.e., repetition support 110, jack 120, spring 160, regulating button 162, spoon 164 and repetition lever 202) about stationary center pin 112, toward string 140. The top end surface 128 of jack 120 presses knuckle 150 upward, 15 to urge the h~ ank 132 and hammer 130 upward toward string 140 (arrow 184). In Figs. 5 and 5A, the lower arm 126 of jack 120 has just come into contact with the let-off button 170. As repetition assembly (i.e., repetition support 110, jack 120, spring 160, regulating 20 button 162, spoon 164 and repetition lever 202) continues to rotate upward from the "at rest" position, the top end surface 128 of jack upper arm 122 follows knuckle 150 upward and to the left (arrow 216), maintaining a rolling point of contact between jack top end surface 128 and 25 knuckle 150. The clearance provided between regulating button 162 and spoon 164 in the "at rest" position leaves the jack upper arm 122 ~ree to ~ove to the left (in the orientation of the drawings) until either the regulating button 162 contacts spoon 164, or jack lower arm 126 30 contacts let-off button 170, whichever occurs first (d~p~n~iin~ upon adjustment, as discussed below).
Finally, referring to Figs. 6 and 6A (in which the position of the i u~/ed action 200 in Fig. 5A is indicated in dashed line for reference), as key 35 depression continues (indicated by arrow 180), jack lower 2i ~7~J
arm 126 presses against let off button 170, jack 120 is forced to rotate in a clockwise direction, about pin 121, thereby causing the top end surface 128 of the jack upper arm 122 to escape (arrow 218) from under knuckle 150.
5 The hammershank 132, carrying hammer 130, is then free to rebound (arrow 220), after the hammer strikes the tensioned piano string 140, and to fall against back check 194.
When the key 102 is released, the; v~_d piano 10 ~qc~L ~ action 200 of the invention returns to the "at rest" position shown in Figs. 4 and 4A, with regulating button 162 spaced from spoon 164 and the upper arm 122 of jack 120 urged (arrow 212) against retainer cushion 206 by return spring 160.
Referring now to Figs. 8 through 16, we will now describe preferred ~ ;r ~S of the invention, in which the jack 120 is held in its "at rest" position by engagement of the jack upper arm 122 against the jack retainer assembly 204, rather than by c.ng:~3 L of the 20 regulating button 162 against spoon 164.
In the ~ t of Figs. 8 and 8A, the jack retainer assembly 204 is shown in its simplest form, with a generally rect~n~l~r jack retainer cushion 206 held in place below the knuckle 150 by rigid support member 208 25 attached directly to h~ sllank 132.
In the: ~ o ~ of Figs . 9 and 9A, a retainer cushion 230 is affixed to adjustable support member 232.
An adjustment screw 234 threaded through h: sl.ank 236 has a head engaged with a pad 238 contacting support 30 member 232. Rotation of screw 234 acts to adjust the position of the retainer cushion 230.
Referring to Figs. 10, lOA and lOB, in; v~,~d ~I-ank 240, e.g. for use in the: '~'i- ~ of the v~_d piano es-ia~ t action 200 of Figs. 6 and 6A, 35 flexible support member 242 has a ~ev-dr~ular end portion 21 q~
244 that is secured in r~L~. J lA~ recess 246 defined by hammershank 240 by a fastener 248, e.g. a pin or screw.
In the: ' ';~ ~ of Figs. 11 and llA, an adjustable support member 2S0 is m--h;n~ to include a 5 fork-like depression 252 at the point of adj~ . The fork 252 is positioned within a slot 254 of collared zlju~l ~ t screw 256, permitting both upward and downward ~lju~l - t. In Fig. llB details of the construction of the adjuat t screw 256 are shown.
In the ' ~ L of Figs. 12 and 12A, a jack retainer cushion 260 is affixed to a relatively more r-lle~hle support member 262 formed, e.g., of soft metal, plastic or similar elastically deformable material. The flexible support member 262 is bent to reposition 15 retainer cushion 260 along arc 264, which in turn allows for precise location of jack 120 relative to knuckle 150.
In the: ' :'i-- L of Figs. 13 and 13A, a jack retainer cushion 270 is affixed to a wooden button 272.
The cushion and button are f itted into a recess 274 20 within a wooden support member 276 attached to hammershank 278, and held in place by a loop of elastic material 280 that fits within a groove 282 defined in support member 276. The position of cushion assembly 270, 272 can be f inely regulated by inserting or removing 25 shims or spacers between button 272 and support member 276 .
In the: '; t of Fig. 14, an extra layer 284, e.g. of ~ ;n or similar material, is affixed to knuckle 150, with an end face 286 of layer 284 acting as 30 the support member for a jack retainer cushion 288.
In the ~ ;- L of Fig. 15, a screw 290 extends through a h: ~I,ank 292. A jack retainer cushion 294 is affixed to the portion of screw 290 that extends below knuckle 150. The screw 290 is inserted into the 35 h: ~llank 292 at an angle, so that raising and lowering 7 ~ 3 the screw 290 adjusts the position of jack retainer cushion 294 relative to knuckle 150.
In the ~ of Fig. 16, a knuckle assembly 330 consisting of an integral knuckle and retainer 5 ;n~ c a body 332 formed, e.g., of wood, defining a knuckle surface 334 having a cover 336 formed, e.g., of b~ ;n. A support member 338 formed, e.g., of wood or plastic, includes a retainer cushion 340, e.g., a felt pad. An adju~l t screw 342 in threaded ~ with 10 member 338 and bearing against the opposed surface 343 of body 332 is used to adjust the position of retainer cushion 340 relative to knuckle body 332. The cantilevered support member 338 is flexible enough to allow a~jua~ t of the position of retainer cushion 340 15 on its free end, while maintaining enough rigidity to hold jack 120 in its "at rest" position (the required holding force being in the range of about 5 to 20 grams).
A~lju~l L of the position of retainer cushion 340 is made, e.g., to ~ ~ te for ~ ssion of the retainer 20 cushion over time and to align the retainer cushion during assembly of the ~C~'A, ~ action. Rnuckle assembly 330 is attached to ~ ~I.ank 132 by, e.g., glue .
In the: ' --;r ~ of Fig. 26, a conventional grand 25 piano action of Fig. 1 is modif ied to include a spring brake 360 in t.}~- aad~d ~ with repetition support 110. When jack 120 is rotated forward during key depression (Fig. 26A), lower arm 362 of spring 160 is in contact with a ledge 364 of jack 120 but is not in 30 contact with spring brake 360. When the key is depressed, spring 160 thus acts to bias jack 120 toward returning to its "at rest" position of Fig. 26.
After release of key 102, and during the return of jack 120 to its "at rest" position under the applied load 35 of spring 160, spring brake 360 contacts lower arm 362, ~i ~i7~
causing lower arm 362 to lose contact with jack 120 before regulating button 162 contacts spoon 164. Contact of lower spring arm 362 with spring brake 360 before regulating button 162 contacts spoon 164 acts to 5 decelerate jack 120, thus helping to -~u~ess noise that may otherwise result from the contact of regulating button 162 with spoon 164 under spring load.
As shown in Fig. 26B, spring brake 360 has a forked end 364 for engaging spring 160. The threaded 10 ~ t of spring brake 360 with repetition support 110 allows the spring force of return spring 160 acting on jack 120 to be adjusted to selectively act on the rotational movement of jack 120 only during a desired portion of the jack's rotation.
Spring brake 360 can also be used with other occAr~ t actions. For example, referring to Figs. 27-27B, spring brake 360 is shown in.vL~vlc.ted into the OCCA, ~1 ~ action of Fig. 4. With jack 120 in its "at rest" position (Fig. 27), lower arm 362 of spring 160 is 20 in contact with a ledge 366 of jack 120. At half key depression (Fig. 27A), spring brake 360 contacts lower spring arm 362 causing lower spring arm 362 to lose contact with jack 120. At full key depression (Fig.
27B), lower spring arm 362 is again in contact with jack 25 120 and acts to return jack 120 to its "at rest" position of Fig. 27. As in the conventional action described above, the loss of contact of lower spring arm 362 with jack 120 causes jack 120 to decelerate prior to contact of regulating button 162 with spoon 164 in the half key 30 depression position of Fig. 27A thus helping with noise ~U}~L Pssion .
Other ' ~ ts of the invention are within the following claims. For example, the relatively low compliance regulating button 162 and/or rigid spoon 164 35 of prior art ~C~'A, ~ actions may be replaced with higher compliance ~ ~s to allow jack 120 to follow the arcuate motion of knuckle 150.
Also, referring to Fig. 17, a high compliance button 162 ' ~.asses against spoon 164 ' allowing the 5 jack 120 to follow the knuckle 150; in Pig. 18, rigid spoon 164 is replaced with compliant spring member 296;
and in Fig. 19, a spring member 298 extends through the repetition lever 300 and engages against the rear surface of knuckle 150, again leaving the jack 120 free to follow 10 knuckle 150.
Also, referring to Figs. 20 and 20A, an; vv~:d repetition lever 310 configured for use with the; .u~,~d h~ ank of Figs. 8 through 16 has a slot d;r- -;nn 312 that is extended and angled or stepped. This is in 15 comparison to the ~OLL~ IA;n~ slot dimension 314 of a conventional prior art repetition lever 316 (shown in Figs. 21 and 21A).
Referring now to Fig. 22, in a jack 120' for use in the; v~_d action of the invention, the front upper 20 corner of the top end surface 128' portion may have an enlarged radius 320 to allow jack top surface 128' to roll against knuckle 150. In ~ v~-~L~=~L~ referring to Figs. 23 and 23A, top surface 128 of conventional jack 120 has a relatively smaller radius only at rear upper 25 corner 322, to ease the return of upper arm 122 under knuckle 150 when the key is released.
Referring to Figs. 24 and 24A, a oval or elliptical cam 800, mounted between rigid supports 801 (only one is shown) on repetition support 110 is 30 rotatable around pivot axis 802 to vary the space between regulating button 162 and the surface of cam 800, thus adjusting the point during the keystroke at which ~n~J~, ~ between opposed surf aces of the j ack and knuckle is initiated. If the space is larger, jack 120 35 will travel with knuckle 150, e.g., as described in Figs.
~ j y~7~3 4/4A through 6/6A. If the space is reduced by rotating cam 800 into position 804 (shown in dashed lines in Fig.
24), the action will function in a more conventional manner. Rotation (arrow 806) of the cam can be affected, S e . g . by a pedal, f inger lever or similar device connected to cam 800 by a flexible or rigid lever linkage.
Similarly, mf '-n; for adjusting the location of spoon 164 may include , e . g ., a rigid bar that moves (left to right in the orientation of the figures), lO activated by a f lexible or rigid lever linkage .
Finally, referring to Fig. 25, where the repetition support lever has a first prede~Drminod arc of travel, r1, about a first center point 112 and the jack retainer assembly has a second predetermined arc of 15 travel, r2, about a second center point 136, the first and second predet~m; n~ arcs of travel are calculated relative to the length of a line, AB, between the first and second center points according to the equation:
rl + r2 < AB
(where A = repetition support pivot, B = hr ~I-dllk pivot, r1 = radius of repetition lever cut out arc, and r2 = radius of h~ ank tab arc) to avoid interference ,. t and to ~--Y;m; 7e performance aspects of the ; _ Ove;l action.
What is claimed is:
Claims (32)
1. A knuckle assembly for an escapement action of a piano, the escapement action comprising:
a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano;
a repetition support bearing against a key of the piano and mounted to pivot relative to the piano in response to depression of the key;
a jack having a first portion extending from a pivot connection with said repetition support; and a spring urging said jack toward an "at rest"
position;
said knuckle assembly for mounting between said first end and said second end of said hammershank, comprising:
a knuckle defining a knuckle surface for engagement with said jack, said knuckle arranged for escape of the jack from engagement with said knuckle surface during depression of a piano key;
a jack retainer for retaining the jack in the "at rest" position with said jack in engagement with said knuckle surface in opposition to force of the spring urging said jack toward the "at rest" position; and an adjustment means acting between said jack retainer and said knuckle for positioning said jack retainer relative to said knuckle.
a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano;
a repetition support bearing against a key of the piano and mounted to pivot relative to the piano in response to depression of the key;
a jack having a first portion extending from a pivot connection with said repetition support; and a spring urging said jack toward an "at rest"
position;
said knuckle assembly for mounting between said first end and said second end of said hammershank, comprising:
a knuckle defining a knuckle surface for engagement with said jack, said knuckle arranged for escape of the jack from engagement with said knuckle surface during depression of a piano key;
a jack retainer for retaining the jack in the "at rest" position with said jack in engagement with said knuckle surface in opposition to force of the spring urging said jack toward the "at rest" position; and an adjustment means acting between said jack retainer and said knuckle for positioning said jack retainer relative to said knuckle.
2. The knuckle assembly of claim 1 wherein said adjustment means comprises an adjustment screw.
3. The knuckle assembly of claim 1 wherein said jack retainer includes a cushion surface positioned to retain said jack in the "at rest" position.
4. The knuckle assembly of claim 1 wherein said jack retainer comprises a flexible support member extending from said knuckle.
5. The knuckle assembly of claim 1 wherein said jack retainer and said knuckle comprise an integral component.
6. A spring brake for an escapement action of a piano, the escapement action comprising:
a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano;
a repetition support bearing against a key of the piano and mounted to pivot relative to the piano in response to depression of the key;
a jack having a first portion extending from a pivot connection with said repetition support and disposed for engagement with said hammershank; and a spring positioned to apply a spring force to urge said jack toward an "at rest" position;
said spring brake adapted to be mounted to said repetition support for selective contact with said spring in a manner to adjust said spring force urging said jack toward said "at rest" position.
a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano;
a repetition support bearing against a key of the piano and mounted to pivot relative to the piano in response to depression of the key;
a jack having a first portion extending from a pivot connection with said repetition support and disposed for engagement with said hammershank; and a spring positioned to apply a spring force to urge said jack toward an "at rest" position;
said spring brake adapted to be mounted to said repetition support for selective contact with said spring in a manner to adjust said spring force urging said jack toward said "at rest" position.
7. The spring brake of claim 6 wherein said spring brake comprises an engaging section for selective positioning of said spring brake relative to said repetition support.
8. The spring brake of claim 7 wherein said engaging section comprises a threaded section.
9. An escapement action for a piano, comprising:
a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano, a knuckle assembly disposed between said first end and said second end of said hammershank comprising a knuckle, a jack retainer, and an adjustment means acting between said jack retainer and said knuckle for positioning said jack retainer relative to said knuckle;
a repetition support bearing against a key of the piano and mounted to pivot relative to the piano in response to depression of the key;
a jack having a first portion extending from a pivot connection with said repetition support and defining a jack surface disposed for engagement with a knuckle surface of said knuckle, said jack arranged for escape of said jack surface from engagement with said knuckle surface during depression of said key; and a spring urging said jack toward an "at rest"
position with said jack surface in engagement with said knuckle surface;
said jack retainer position being adjustable to retain said jack in the "at rest" position in opposition to force of said spring.
a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano, a knuckle assembly disposed between said first end and said second end of said hammershank comprising a knuckle, a jack retainer, and an adjustment means acting between said jack retainer and said knuckle for positioning said jack retainer relative to said knuckle;
a repetition support bearing against a key of the piano and mounted to pivot relative to the piano in response to depression of the key;
a jack having a first portion extending from a pivot connection with said repetition support and defining a jack surface disposed for engagement with a knuckle surface of said knuckle, said jack arranged for escape of said jack surface from engagement with said knuckle surface during depression of said key; and a spring urging said jack toward an "at rest"
position with said jack surface in engagement with said knuckle surface;
said jack retainer position being adjustable to retain said jack in the "at rest" position in opposition to force of said spring.
10. An escapement action for a piano, comprising:
a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano, a repetition support bearing against a key of the piano and mounted to pivot relative to the piano in response to depression of the key;
a jack having a first portion extending from a pivot connection with said repetition support and disposed for engagement with said hammershank;
a spring positioned to apply a spring force to urge said jack toward an "at rest" position; and a spring brake mounted to said repetition support for selective contact with said spring in a manner to adjust said spring force urging said jack toward said "at rest" position.
a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano, a repetition support bearing against a key of the piano and mounted to pivot relative to the piano in response to depression of the key;
a jack having a first portion extending from a pivot connection with said repetition support and disposed for engagement with said hammershank;
a spring positioned to apply a spring force to urge said jack toward an "at rest" position; and a spring brake mounted to said repetition support for selective contact with said spring in a manner to adjust said spring force urging said jack toward said "at rest" position.
11. The escapement action of claim 10 wherein said spring brake comprises an engaging section for selective positioning of said spring brake relative to said repetition support.
12. The escapement action of claim 11 wherein said engaging section comprises a threaded section.
13. The escapement action of claim 10 further comprising a knuckle assembly disposed between said first end and said second end of said hammershank comprising a knuckle, a jack retainer, and an adjustment means acting between said jack retainer and said knuckle for positioning said jack retainer relative to said knuckle;
said jack defining a jack surface disposed for engagement with a knuckle surface of said knuckle, said jack arranged for escape of said jack surface from engagement with said knuckle surface during depression of said key;
said jack retainer position being adjustable to retain said jack in the "at rest" position in opposition to force of said spring.
said jack defining a jack surface disposed for engagement with a knuckle surface of said knuckle, said jack arranged for escape of said jack surface from engagement with said knuckle surface during depression of said key;
said jack retainer position being adjustable to retain said jack in the "at rest" position in opposition to force of said spring.
14. The piano escapement action of claim 9 or 13 wherein said adjustment means comprises an adjustment screw.
15. The piano escapement action of claim 9 or 13 wherein said jack retainer includes a cushion surface positioned to retain said jack in the "at rest" position.
16. The piano escapement action of claim 9 or 13 wherein said jack retainer comprises a flexible support member extending from said knuckle.
17. The piano escapement action of claim 9 or 13 wherein said jack retainer and said knuckle comprise an integral component.
18. A piano escapement action assembly, comprising:
a hammershank having a first end mounted to a piano for pivoting movement and a second end carrying a hammer to strike a string;
a knuckle assembly disposed between said first end and said second end of said hammershank comprising a knuckle, a jack retainer, and an adjustment means acting between said jack retainer and said knuckle for positioning said jack retainer relative to said knuckle;
a jack having a jack surface in engagement with a knuckle surface of said knuckle in an "at rest" position, said jack being arranged relative to said knuckle and to a key of the piano to convey motion of the key to said knuckle, and to disengage said jack surface from said knuckle surface during depression of the key; and a spring disposed to urge said jack toward the "at rest" position;
said jack retainer position be adjustable to oppose said spring to retain said jack in the "at rest"
position, and allowing said jack, in response to depression of the key, to move in a coupled rotary motion with said knuckle assembly prior to disengagement of said jack surface from said knuckle surface to allow said jack surface engaged with said knuckle surface to remain engaged with said knuckle surface during movement of said knuckle.
a hammershank having a first end mounted to a piano for pivoting movement and a second end carrying a hammer to strike a string;
a knuckle assembly disposed between said first end and said second end of said hammershank comprising a knuckle, a jack retainer, and an adjustment means acting between said jack retainer and said knuckle for positioning said jack retainer relative to said knuckle;
a jack having a jack surface in engagement with a knuckle surface of said knuckle in an "at rest" position, said jack being arranged relative to said knuckle and to a key of the piano to convey motion of the key to said knuckle, and to disengage said jack surface from said knuckle surface during depression of the key; and a spring disposed to urge said jack toward the "at rest" position;
said jack retainer position be adjustable to oppose said spring to retain said jack in the "at rest"
position, and allowing said jack, in response to depression of the key, to move in a coupled rotary motion with said knuckle assembly prior to disengagement of said jack surface from said knuckle surface to allow said jack surface engaged with said knuckle surface to remain engaged with said knuckle surface during movement of said knuckle.
19. The piano escapement action assembly of claim 18, further including a spring brake for selective contact with said spring in a manner to adjust said spring force urging said jack toward said "at rest"
position.
position.
20. The piano escapement action assembly of claim 18 or 19 wherein said adjustment means comprises an adjustment screw.
21. The piano escapement action assembly of claim 18 or 19 wherein said jack retainer includes a cushion surface positioned to retain said jack in the "at rest"
position.
position.
22. The piano escapement action assembly of claim 18 or 19 wherein said jack retainer comprises a flexible support member extending from said knuckle.
23. The piano escapement action assembly of claim 18 or 19 wherein said jack retainer and said knuckle comprise an integral component.
24. The piano escapement action assembly of claim 18 or 19, further comprising:
a repetition support lever;
a relatively rigid spoon mounted for movement with said repetition support lever; and a regulating button mounted for movement with said jack.
a repetition support lever;
a relatively rigid spoon mounted for movement with said repetition support lever; and a regulating button mounted for movement with said jack.
25. The piano escapement action assembly of claim 24 wherein said spoon and said regulating button are disposed at spaced apart positions in the "at rest"
position of said jack.
position of said jack.
26. The piano escapement action assembly of claim 24, wherein said repetition support lever has a first predetermined arc of travel about a first center point and said jack retainer assembly has a second predetermined arc of travel about a second center point, and said first and second predetermined arcs of travel are calculated relative to spacing between said first and second center points to avoid interference engagement.
27. The piano escapement action assembly of claim 18 or 19, further comprising:
an adjustable regulating member mounted for movement between a first position allowing rotation and following of said jack, and a second position restricting movement of said jack prior to disengagement.
an adjustable regulating member mounted for movement between a first position allowing rotation and following of said jack, and a second position restricting movement of said jack prior to disengagement.
28. The piano escapement action assembly of claim 18 or 19, wherein said jack retainer is mounted to maintain a rolling point of engagement of said jack surface with said knuckle surface, thereby to minimize sliding friction between said jack surface and said knuckle surface during a portion of the movement of said action before said disengagement.
29. The piano escapement action assembly of claim 19, further comprising:
a repetition support lever;
a relatively rigid spoon mounted for movement with said repetition support lever; and a regulating button mounted for movement with said jack, said spoon and said regulating button being in contact in the "at rest" position of said jack.
a repetition support lever;
a relatively rigid spoon mounted for movement with said repetition support lever; and a regulating button mounted for movement with said jack, said spoon and said regulating button being in contact in the "at rest" position of said jack.
30. The piano escapement action assembly of claim 19, further comprising:
a repetition support lever, said spring brake being mounted to said repetition support;
a relatively rigid spoon mounted for movement with said repetition support lever; and a regulating button mounted for movement with said jack.
a repetition support lever, said spring brake being mounted to said repetition support;
a relatively rigid spoon mounted for movement with said repetition support lever; and a regulating button mounted for movement with said jack.
31. The escapement action assembly of claim 30 wherein said spring brake comprises an engaging section for selectively positioning said spring brake relative to said repetition support.
32. The escapement action assembly of claim 31 wherein said engaging section comprises a threaded section.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US61665696A | 1996-03-15 | 1996-03-15 | |
| US08/616,656 | 1996-03-15 | ||
| US78805897A | 1997-01-23 | 1997-01-23 | |
| US08/788,058 | 1997-01-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2199783A1 true CA2199783A1 (en) | 1997-09-15 |
Family
ID=27087825
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002199783A Abandoned CA2199783A1 (en) | 1996-03-15 | 1997-03-12 | Piano escapement action |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0795848A3 (en) |
| JP (1) | JPH1031480A (en) |
| KR (1) | KR19980069715A (en) |
| CA (1) | CA2199783A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8143506B2 (en) * | 2008-01-11 | 2012-03-27 | Clark Bruce E | Hammer assembly for grand piano |
| JP6464867B2 (en) * | 2015-03-25 | 2019-02-06 | ヤマハ株式会社 | Support assembly and keyboard device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR398726A (en) * | 1909-01-23 | 1909-06-12 | Joseph Herrburger | Grand piano mechanics |
| US1992939A (en) * | 1933-05-06 | 1935-03-05 | Thayer Action Company | Piano action |
| US2138517A (en) * | 1937-03-18 | 1938-11-29 | Sieveking Martinus | Piano-action spring |
| US5511454A (en) * | 1994-11-17 | 1996-04-30 | Steinway Musical Properties, Inc. | Piano escapement action |
-
1997
- 1997-03-12 CA CA002199783A patent/CA2199783A1/en not_active Abandoned
- 1997-03-13 EP EP97301687A patent/EP0795848A3/en not_active Withdrawn
- 1997-03-15 KR KR1019970008896A patent/KR19980069715A/en not_active Withdrawn
- 1997-03-17 JP JP9063580A patent/JPH1031480A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1031480A (en) | 1998-02-03 |
| EP0795848A3 (en) | 1998-08-05 |
| KR19980069715A (en) | 1998-10-26 |
| EP0795848A2 (en) | 1997-09-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |