IMPROVEMENTS IN PIANO ACTIONS
Year: 1884

page_text: I DAVID FITZGERALD DOWNING Captain in the Royal Regiment of Artillery in
Her Majesty's Land Forces, stationed at Woolwich in the County of Kent do
hereby declare the nature of my invention for IMPROVEMENTS IN PIANO ACTIONS
to be as follows:-
I employ rolling surfaces. of suitable curvature or otherwise whereby the motion
required may be transmitted in any desirable form without friction, the rolling
contact being preserved by alternating flexible threads, bands hairs, fibres or wires
of suitable material.
In pursuance of this method the following alterations may be made in any
existing piano action.
1. The part known as the "Hopper" may be replaced by two or more pieces
connected together in the manner described and connected similarly or by ordinary
joints to the Key or parts leading to it, on the one hand, and the Hammer or parts
leading to it, on the other hand-these pieces for convenience of reference may be
called the "Hopper Pieces "By these pieces the contact between the Key & Hammer
is 'made continuous throughout-the fall of the Hammer from the String after
striking being provided for by the form of the curves introduced, and their motion
in rolling upon one another as arranged-A Check Action to ensure rapid
reengagement may be further provided by the addition of other rolling pieces
connected to one another and to the two (or more) Hopper Pieces by the rolling
joint if necessary and to standing parts of the framework if necessary by the rolling
joint or otherwise. These additional pieces may also serve to control the motion
of the Hopper Pieces and form a continuous piece of inechanism without friction_
This replacement of the Hopper is intended to eliminate certain disadvantages viz.
loss of power and uncertainty of touch and to enable the Hammer to be made
heavier if desired.
.
2. The Guide Pin under the front of the Key may be replaced by a rolling piece
or pieces connected by the rolling joint to the Key properly prepared and to
standing parts of the framework provided-This will eliminate the friction and
consequent loss of touch experienced when a note is struck sideways, and will
prevent" "rattling" of the keys.
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3. Any of the joints in which there is undue friction may be replaced by the
rolling joint;
غذية
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page_text: I DAVID FITZGERALD DOWNING Captain in--the Royal Artillery stationed at
Woolwich in the county of Kent do hereby declare the nature of my invention
for IMPROVEMENTS IN PIANO ACTIONS and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
I employ rolling surfaces to avoid friction and to obtain certain motions in
the most convenient form.. .The rolling contact is maintained by flexible liga-
ments (of any suitable material) which lie between the surfaces in contact and
alternate in their attachment from one to the other.
Thus in Fig. 1 in order to cause the curve ab to roll against the face A B instead
of slipping along it, when the point C is moved in the direction indicated by the
arrow, a ligament is attached to ab at b & to A Bat A-Similarly, when the motion
is reversed, and C moves in the opposite direction to the arrow, another ligament
running in a parallel direction to the first but attached at B and a will prevent
slipping in the opposite direction. If the motion to be transferred from ab to A B
is normal to the curve at the point of contact there will be no strain upon the
ligaments and the more nearly the motion approaches this condition the less strain
there will be. The ligaments therefore are not intended to transfer power but
merely to retain the working parts in their correct positions.
When the curve or curves are reduced in length to approach a point in section.
the effect is the same as if a pin centre were employed, the strain on the ligaments.
is increased but there is no friction other than in the substance of the ligaments.
Fig. 2. Shows certain applications of this mechanism. The hopper in an ordinary
action is replaced by two pieces de & ef jointed at d, e and f-the curves may be.
arranged to give aggregate motion.
The position shown is that assumed when_the_hammer_is_at_its_highest-point-
before receding from the string its weight is supported by the pressures being
normal to the curves at e. the slightest upward movement of the arm G will
break this support, the curves at e rolling to the right and thus shortening the
support from to d. The rolling of the curves is governed by the ligament 'g g,
which is attached to the piece fe at g and to the framework at g, this attachment
is made adjustable by a screw pin in order to set the striking point of the hammer
when the parts are assembled. The ligament gg, is in tension until the striking
point is reached when it buckles and allows for the fall of the hammer.
The arrangement described necessitates a reengaging check which is shewn
at h, k, l, m n H. H is an arm attached to the hammer but, and supplied at its
extremity, with the usual arrangement to engage in the rebounding check K if
desired. On this arm slides a collar to which is attached the re engaging check.
This consists of 3 pieces h, k, ln, & l m jointed together at 1 & k, to the hopper
piece e fat N, to the collar on the arm H at m and to the framework at n. The
curves at are arcs struck with radii l m and I n. The action is as follows:
As the hopper pieces rise the collar on the arm H receives no support from the
check but in the position indicated the support of the hopper pieces, being removed

page_text: by their rolling to the right, the weight of the hammer is transferred through ml
&n to the framework & it is thus held till the hopper pieces have re engaged. By
virtue of the curves at no lifting of the hammer takes place on the key being
pressed beyond the striking point.
At Z is shown an arrangement for soft pedal whereby the length of stroke of the
hammer is shortened without disarranging its striking point. The thrust of the key
lever is transferred to the arm G through a lifter composed of a bar p q & the
curved piece r 8 g the curve of which is such that in the position shown the point
of contact can be transferred from to s without altering the positions either of
key lever or arm G the effect of this is that when the key. lever returns to its
normal position the arm G & consequently the hammer will not follow so low in
consequence of the increased leverage of the Lifter. The bar p q is jointed to the
key lever at p & to the curve piece at q it is actuated by the pedal through the
pieces tv & P. P being attached to the frame work by an arm pivoting at a point
opposite to P & tv being pivoted to p q at t & to P at v.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is.
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1. The use in piano actions of rolling surfaces the rolling motion being main-
tained by flexible ligaments of suitable material alternating in their attachment
substantially as and for the purpose described.
2. The replacing of the hopper by two pieces connected by the joint described
in 1.
3. The Soft Pedal action in which a curve is employed to shorten the stroke of
the hammer without altering the striking point or losing contact between the parts
substantially as described.