Note: Descriptions are shown in the official language in which they were submitted.
Titl.e~ I'IOh FOR l~P~lGllT f'LAh~
.[nventor: Pau,L GerharcL W.al.l,
oi' Ki.t,chenert Ontarlo, (',anada
B~KGMOUND OE~ HE INV_N'l'LON
'L'his i,nvention rela-tes to an act:ion f'o:r an upr:i,gh-t
piano~ the ac-tion be~n~ the mechanism which transm:its the
impetus given by the player's -touch to the pi.ano strings.
An i.dea:l p:i.ano ac-t:ion would have -the f'ol:Lowing
5 characterist:ics: Firs-tly, the piano player shou:Ld have good
contro:l over the hammer blo~, in order to be able t.o vary
the character of the no-tes played. Second:Ly, -there must be
escapement so -that the harnmer can rebound freely after
striking -the 9 tring, even i.f -the key is stil:L being
10 d.epressed by the player. Thirdly, the motion of' the hammer
shoul.d be cheaked after i-t has rebounded from -the s-tring.
:Fourthly, the player should be able -to :repeat -the note
immediately and continuously it' desi.red, even if the key is
not :thlll.y released. .E~`i:l'thly, the damping a.ction should be
15 instantaneous and silent.
Diff'erent p,iano actions approach these ideals to
va:ry:ing deg-.rees. The ac-tion of a grand piano is generally
considered to much more cLose.ly approach these ideals than
the ac-tion of' an upri.ght pi.ano. For example, the grand
20 p;"ano ac-tion a.L:Lows :t'or immediate and continued repetition
of a note, even i.f the key has no-t fully re-turned -to its
normal (undepressed) positi.on, whi:l,e the upright action
requires that the key return to or almost to its no:r.~mal
posi-tion be-t'ore the note can be repea-ted. This dit'ference
`~
is clue to the superior d~si~n o~ the grand plano ~hippen
assen~bLy.
The conventional uprl~ht piano actLon has a singrLe
simpLe escapement, tha-t of -the hammer trom the jack of the
whippen assembly. Ttle head of the jack is ordinarily in
contac-t wi-th the bu-tt of the hammer. When the key is
depressed the jack is moved upward:Ly, forcing the bu-tt o:f
-the hammer -to rotate upwardly about the pivot poin-t on its
flan~e. ~t a certain point bef`ore the nammer contacts the
string, escapement takes place. The jack rotates out -from
utlder -the bu-t-t oi`-the hammer, freeing the hammer to continue
under its own inertia towards the string and to rebound
freeLy a~ter impact. After rebounding :~rom the string, the
ca-tcher is caught by the backcheck and held in this posi-tion
as long as the key is depressed. In order ~or the no-te to
be repeated, -the key must be -fully released or very near]y
so, so tha-t -the jack can drop back in-to pos:ition under -the
hammer butt.
By contrast, in the grand piano action the jack
20 can drop back under the knuckle before the key is fully
released. In a grand piano action, there is a compound
escapemen-t, involvlng the jack coming into contact wi-th a
regulating button and be:ing forced to rotate out from under
-the knllckle o~ the hammer, al~d also the repeti-tion lever
25 comin~ in-to contact with a drop screw. As the key is
depressed, -the escapement -takes p:lace and the hammer f`lies
:treely towards the string under i-ts own iner-tia. A-~-ter
reboundi.ng from the string, the catcher :is caught by the
backcheclc and he:Ld in this position as long as the key is
35~)
depressed. Then, when -the key is released slightly, the
repet~tion lever supports the knuck:le, allowing the jack tc>
drop bacli into pos:ition. Consequently, if the key is
c3epressed again, the jack~ can immediate:ly move upwards and
5 attack the knuck]e. Repea-ti,ng a no-te immediately and
continl~ously is thus -far easier than on an upri~ht piano.
Checking in a grand piano action must generally be
more secure than in an upright action, due -to the force in
the direction of` the string exerted by -the repet:i-tion lever
10 on the knuckle on -the hammer shank.
Wi-th respect to damping in a grand piano, the
damper is he:Ld onto the s-tring by gravity. ~s soon as the
Isey is released, the damper starts to drop back onto the
string. The damper is a:Lso under the direct control of the
15 key. When the key is depressed the ef'fect produced by
gravity on the damper must be overcome. The f`act that the
damper is under direct control of -the key and that the
damper is held on the s-tring only by gravity gives the grand
piano a precise -touch which is appreciated by many players.
By con-trast, the damper in -the upright piano is
held onto the string by means of a small damper spring.
When -the l~ey is depressed -the force e,Yerted by -the spring on
the damper must be overcome. Overcoming -this f`orce is a
gradllal process and the touch of'-the uprigh-t piano keys is
25 oonsequen-tly somewhat dit'f'erent from that of'-the grand
piano. I'he spring may also deteriorate with time and
thereby produce an inconsistent touch. If sufficien-t
deterioration occurs, the damper may be lef-t in imperf'ec-t
contac-t with the string, -thereby reducing its abili-ty to
~2~5~
damper) st:ring ~ibration. Also. the damper is not under the
di.rect c~ontrc).l of` tt)e key but ra-ther is activa-ted via an
in-l-,ermedia-te lever. These :f'~ctor~ resul-t in a damper action
which ha.s a :less conl,rol:Led and con~i.sten-t touch and which
5 is more prone to Inechanic~al problems than -the damper action
in a. grancl pi.ano.
:In addit,ion t,o sllperior note repet.it,ion, -the orand
piano acti.on ha.s an advan-tage over the upright p:iano action
in relation to the operation ot' the .left or soft pedal,
la.rgely due -to the -Eact -tha-t -the hammer and damper actions
are s-t.ructurally i,ndependen-t of each other.
In the g:rand piano, when the left peclal is
depressed, -the key:t`rame s:Lides .la-terally on -the Iceybed. '['he
hammer a,c-tion is attached -to the keyframe, and consequently
i,t also slides lat.era:i.ly ~hen the soft pedal is depressed.
T f' a key in the treble section is p:Layed, -the hammer
ordi,narily strikes three strings. Ilowever, i.-t` the key is
played whi:Le the sof't peda,l is being depressed, the hammer
wilL move latera:lly with -the keyframe and strike only -two
strings. A ~ofter sound w:i.ll consequen-tl.y be produced.
Tn a conventional upright piano, movement of the
key:;rame i.s not posslble, because the dampers are attached
to the ma:in action ra,i:L, as are -the hammer t':Langes. Si,nce
-the dampe~rs must not move :in relation -to the strings
~because they must be seated properly on the stri,ngs in
order to d.ampen string vibra-tion), this means -t:ha-t the hammer
ac-tion, be:ing supported on -the same main ac-tion raiL~ cannot
move with respect to the strings. By contrast, in -the grancl
pi,ano, -the dampers are at-tached -to a damper flange rail
whic.h -is independe:nt f'-rom t,he main ac-tion rai.l. 'I'he
keyframe can there~ore t)e made f'ree to move l.a-teraLly when
the soft pedal j a, used ~ l thou-t having -the da.mpers sl1i.f't,
:[n ~ convent1onaL up:l~i,ght piano, softening is
achieved by having the hammer rail move the hammers closer
to the strings when t,he sof't pedal is depressed. I:f a key is
played with -the soft peda:l depressed, some o:f the mo-tion
normal:ly impa~ted -to the hammer is ,Los-t because o-f' the
shorter distance between the hammers and -the s-trings and
because of 1;he shorter period ol` contact between the jack
and the hamme:r butt. resu:Lting f'rom the shif`ting of -t.he
hammer raiL, so the hammer strikes -the s-t.rings wi,-th :Less
force than normal. ~ hammer in the -treble section of -the
pi,ano will, normaLI.y strike three str:ings, bu-t will strilse
them with ,less t'orce -than usual when the soft peda:L is used,
and wi.,L:I theref'ore produce a sof'te-r sound.
Si~MMARY OF l`HE :tNVEN'I'ION
I-t is an objec-t of the present invention -to
provide an action for an upri.ght piano whi.ch emula-tes or
si.mu:Lates the grand. piano action. The ac-tion a,Llows no-tes
to be repeated even when the key has not ful,l.y re-turned to
its norma,l positi,on, and beca.use -the hammer action and.-the
damper act:ion are :independent, allows the keyframe -to move
,I,atera:L:Ly ~hen -the so:t'-t pecla:L is depressed.
In the ac-tion of the presen-t inven-tion, the
25 conventional upright piano whippen and hammer bu-tt have heen
replaced with ones such as those in -the grand piano. Thi,s
a:L:Lows for immediate and continued repe-tition of' no-tes. The
da.rnper and hamme:r of -the -pr~esent ac-tion are not :located on
the same action rai:l, bu-t rather a:re set Up independen-tl.y on
their own action :rai..ls. rl'his independent s-tructu:re al:Lows
f'or severa:L advantages. Firs-t:Ly, the dampers may be
arranged in such a manner as to be activated 'by gravi-ty, as
is -the case i.n a grand p:iano, and not by means of a spring,
as is -the case in an llpri.gh-t piano. SecondLy, the keyframe
and hammer ac-t:i.on can be al:lowed to slide laterally on the
keybed when the sof'-t peda:l. i.s depressed, wi.thollt moving the
dampers, -thereby a:l:Lowing for -the act:ion of` a true so~-t
pedal.
The acti.on allows the upright piano to pla.y very
much as if it were a grand piano, having a -touch simila.r or
identica:L to -that ot' a grand piano. The ac-tion is arrangecl
in sllch a manner as to fit easil.y int.o the cornpact size and
shape of the l~pright piano.
Fea-tures of the inven-tion wil:L be descr:ibed or
will become apparent in the course o:f -the fol.:Lowing de-tailed
description o:f' the pret'e-rred embodiment of the invent:ion.
BRIE.F DESCXIPTION OF' THE DR~WINGS
The preferred embodiment of.' -the invention will now
'be descri'bed with reference to the accompanying drawings, in
which:
Fig. I is a side view of one no-te element o~ the
ac-tion, showing it in the unac-tllated position; and
Fig. 2 is a view correspondi.ng to Fig. :L, e~ploded
-to StlOW the independence of the hammer ac-tion and the damper
action.
5~
~ l.ED DES(~R:IPTION Oli` I'H~ PRE~`:ER:RED EMBODIMEN'I`
. ~
'I:'he structure and opera-t.ion QL' the act1on are as
follows, described with ref`erence to Fig. :I.
Y'he player depresses the :L'ront of' the liey tnot.
shown)~ which raises -the back of -the key :I, the key be:ing
insta.L:Led in the usua.L lever L'ash:i.on on -the key:t'rame 2.
'rhe upwaId movemen-t o-f the back of` the key 1 raises the back
check lever 3 via capstan screw ~ causing it to rota-te
about its f'l.ange 5, ins-taLled on a backcheck lever raiL 6.
The upward movemen-t o-f'-the back check lever 3 li-fts caps-tan
screw 7, causing the whippen assembly to move upT~ardly,
ro-tating ill about i-ts flange 8 wh:ich i.s a-ttached to -the
whippen :rail 9.
The whippen assembLy is essen-tialLy that of a
grand piano, comprising a l~h:ippen arm :L0 p:ivota:Lly connec-ted
near :it.s :L'ront end to a flange 8 on whippen rail 9, a
repeti-t:ion lever lL p:ivo-tally connected t.o a repetition lever
flange 12 protruding upward:Ly .t'rom an in-termediate point of
the whippen arm `L0; a jack 13 pivotalLy connected to the
wh:ipperl arm l0 nea.r the rear end ot' the whippen arm, the jack
20 comp:r:ising an upward:I,y-directed a-ttack a:rm l'l passing
th:rough a slot 15 provided in -the repetit:ion lever :L1 and a
rea.rwardly-rli:rected bel].-crank arm 16 .integral wi-th -the
attack arm L~L. A repeti-ti.on :Lever spring L7 biases a jack
reglllating but-ton 18 on the attack arm 14 :forwardly against
25 a stop :I9 :Eor positi.onin~ the end o:t' the a-ttack arm l~L
di:rectly under the knuckle 20, and at -the same -t:ime `biases
t.he repeti.tion lever 1l upwardly against a felt pad on
~ep~-?t~ i t.ion lever screw 2I s~ch -that the repetition Lever II
is prevent,ed lrorn orcIlnariI~ :Iying below -the end ~f the
at-tack arm 1.~1 -in the a,re.a o:f` the knIlckLe 20. The stop l~J
and -the repe-tltic>n :I.ever screw 2l a,re both carri.ed on a stop
5 sllpport a:rm 22.
The l~pward movement oi'-t,he whippen assemb.Iy
produced by depressing the key :L causes the Jack i.3 -to move
upwards so -that its at,t,ack a.rm ,1 'I "at-tacks" the kn~Ick:Le 20 on
the ca-tcher arm 23. The attack on -the knuckle 20 causes the
lO catcher arm 23 and in-tegra:l hammer shank 2~ to ro-tate abou-t
the hamme:r -Flange 25 ins-ta:Lled on main action rail 26,
thereby urging -the hammer 27 away from i-ts resting positi.on
near the hammer rai:l. 28, -towards the string 30. The hammer
27 is ord-irlari.I.y ass:isted -to its resting posi-tion by a hammer
15 blltt spring 3:L be-tween the hammer shank 2'I and spr:ing :rail
29.
Jus-t before the hammer 27 hits the str:ing 30, -the
bell-crank arm 16 of -the jack 13 comes into contac-t with the
regulating button 32 a-t,-tached undernea-th main ac-tion rai.:L
20 26. The regul.a-ting but-ton 32 causes the jack 13 to rota-te
counter-clockwise (with respect to the viewpoint used in the
dra,wings), i.e. so that -the attack arm 14 moves rearwardly
(i.e. gene:ra:L:Ly away t'rom the :t'ront of'-the piano and towards
the string 30) and away from underneath the knuck:le 20. At
25 essen-tial:l.y the same time, the rearward end of` repeti.tion
lever :Ll comes into contac-t with the drop sc:rew 33 installed
in hammer :t`lange 25. The drop screw 33 preven-ts any f'urther
upward movement o:f -the repeti-tion lever :LI. ThlIs the drop
screw 33 and the regulating but-ton 32 controL the compound
~22~5~
eS(`.lpelll~-'llt: 0~' t.he hamrner assemb.l.y t'rom -the repe-t.i-ti,on lever
1:l and attach arm :1 I re.spec-t:ive:ly. When th-is escapement
occurs, the hammer 2'i :f'lies t'reely tol^7ards the st.ring 30.
'I'he da,mpi 11~ a( t,ion will now be described. A.s can
be seen cleGIrly t'.7o~ F-ig. 2, -t,he damping action i.s
independent; Or the hammer ac-tion, and is under direct
control. of` the back oi' t,he key l. As t,he key I is
depressed, -the ri.s:i,n~ back end of the key :I comes in-to
contact with -the dampe:r Lever 3~l, which is pivotal.ly
insta:Ll.ed on f`:l.arlge 35 moun-ted on ~ower damper lever rai:l
36. The resul.ting upward ro-tation of the damper lever 3~l
Li:fts -the damper wi:re 37 connec-ted to the damper :I:i.f'-ter
flange 38, u:L-timate1y causing the upper damper .I.ever 39 to
ro-tate abou-t i.ts f'l.ange 40 ins-ta:lled on -the upper damper
lever rall. ~1. This ro-tation causes the damper 'i2 -to be
lif'ted of:t' the s-tring 30. Lead weights 43 in -the damper
:Lever 34 cause -the damper '12 to return -to the string 30 as
-the key l starts returning to i-ts res-ting posi-tio:n.
The right pedal li-ft,s al:L of the dampers ~12 from the strings
20 30 by ac-ting to li.f-t -the damper lif-t :rai:L 44 which raises
the damper lever 34.
When the hammer 27 s-trihes -the string 30 and
rebounds, being -t`ree -to do so by vir-tue of the escapemen-t,
the rebounding knuck:Le 20 iands on -the repeti-ti.on lever 11.
25 Since -the downward force ot`-the rebounding hammer is greater
-than the orce of'-the repe-ti.-tion l.ever spring 1.7, the
knuckle 20 pushes -the repe-t:ition lever ll down, causing i-t
to pivo-t about its :t'lange 12. The downward moti.on continues
unti1 the mo-tion of the hammer 27 is checked when -the
2~
catcher 1~ t'a1:1s i1~tO the back check ~16, wh:ich :is moved :into
poxi tiOIl by vir-tue of the rais-ir1g of the back check leVt?r ~.
As in a g:rand ~ction, -the checki.ng :is qu:Lte secure, whic11 :i.s
necessa:ry hecause of' the presence ot' the repeti.-tion l~ver.
'I'he hammer remains in -the checked posi-tion as long as the
key l is depressed.
At this poin-t the key 1 is t'ul.Ly depressed, the
repetitioll Lever 1:1 :is sl:ight:ly depressed away t'rom
repetition lever screw 2] and is e~er-ting upward pressure on
the knuck]e 20 by virt~ie o:f the upward -force wh:ich the
sprin~q 17 e~erts on -the repeti-tion lever Ll. ~s long as the
key remai.ns depressed1 -the llp~ard force of the repetltion
lever spring -tr.~ies to push the knuchle 20 up, but canno-t
because the hammer :is held in check. However, as soon as
the key l is sligh-tly re:Leased and s-tarts to come up, the
back check 46 releases the catcher ~}5, and the upward f'orce
exerted by the repe-ti-t:i.on lever 1l on the knuck.Le 20 acts to
suppor-t the knuck:Le 20 briefly, allowing the attack arm :1'1
of'-the jack 13 to return to its starting position unde:r the
20 knuckle 20 as soon ax it is clear o-f' the regulating button
32. rL'hi.s immediate repositioning of'-the a-ttack arm l/1 of
the ~jack l3 allows for immediate and continued repetition of
the note if' desired, withou-t need f'or the key :1 to be fu:Lly
released.
When the soft pedal (not shown) i.s depressed, -the
keyf':rame 2 and hammer action, including the backcheck :Lever
rail 6, -the whippen rai:L 9, main action rail 26, and spring
rai:L 29, slide lateral:l.y on t.he keybed (not shown). If the
key l is depressed whi.le the soft pedal. is depressed, the
122~9SO
h.lmmer 2'7 t,hllCI strikes -f`e~er str-irl~s than usllFll, -thereby
producing a so~'-te~ sollnd.
rl'his is possible bec~use as in a ~and pi,ano, the
damper action is comple-tely independen-t of -the hamrner act:ion
(as shown clearLy in ~'ig.2), ~o t,ha-t -the key-~'rame and t,he
hammer action can be IllO~f? I.a-terally withou-t af'f'ec-ting -the
damping mechanism.
