Improvements in and relating to Damping Actions for Pianofortes.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Damping Actions for Pianofortes.
We, JOHN GLOUGH MURDOCH, Junior, of St. Georges Road, Regents Park,
Pianoforte Manufacturer, and JOHN JULIAN LOUIS FUREY, of 43, Constantine Road,
Hampstead, Pianoforte Maker, both in the County of London, do hereby declare the
nature of this invention to be as follows:-
"<
Our invention relates to improvements in the damping action or mechanism of
that class of pianoforte action known as the "sticker-check" (which includes
actions known as the "Costa," "Combination," Acme," "Imperial," "Princess,"
and similar actions) in which the blow is transmitted directly from the key: the
object of our said invention is to produce a simple cheap efficient and more lasting
means for damping with this class of action.
Hitherto the distance between the button at the bottom of the damper wire and
lever has been so small that the slightest shrinking of the string into the damper
felt has prevented or impeded the damping. This sinking almost invariably takes
place to a greater or less extent and numerous attempts have been made to produce
a mechanism whereby the effects will be obviated; such attempts have however
either proved too costly or inefficient for the purpose.
According to our present improvement to overcome the difficulty we extend the
wooden shoe or lever that works upon the key, without in any way destroying the
efficiency of the said shoe, and we prolong the damper wire to this shoe-extension
instead of working from an arm in the sticker. By this arrangement we are able to
obtain an increased distance between the damper wire button and the shoe which is
sufficient to ensure that the button will not rest on the shoe or lever and thus
should the damper sink, the usual derangement of the damping mechanism is
avoided.
By our improved arrangement also a rise of the body of the damper amounting
to three eighths of an inch may be obtained thus ensuring that the head of the
damper recedes from the string a corresponding distance instead of the limited
one sixteenth of an inch obtainable hitherto. A further advantage is that the weight
of the damper is removed from the sticker and therefore the full effect of the touch
on the key is transmitted to the hammer and the wear of the sticker centre avoided.
Dated this 6th day of April 1897.

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Damping Actions for Pianofortes.
I, JOHN GLOUGH MURDOCH, Junior, of St. George's Road, Regents Park, Pianoforte
Manufacturer, and JOHN JULIAN LOUIS FUREY, of 43, Constantine Road, Hampstead,
Pianoforte Maker, both in the County of London, do hereby declare the nature of
this invention, and in what manner the same is to be performed, to be particularly
described and ascertained, in and by the following statement:-
Our invention relates to improvements in the damping mechanism of that class of
pianoforte action known as the "sticker-check" (which includes actions known as
the "
Costa," "Combination," "Acme,". "Imperial," "Princess” and similar
actions) in which the blow is transmitted directly from the key; the object of our
suid invention is to produce a simple cheap efficient and more lasting means for
damping with this class of action.
Hitherto in actions such as above referred to the damper has always been worked
from the sticker and the distance between the button at the bottom of the damper
wire and the sticker-lever has been so small-barely nd of an inch or a mere
veneer "that the slightest sinking of the damper-felt on to the string has
prevented or impeded the damping. This sinking almost invariably takes place to
a greater or less extent and numerous attempts have been made to produce a
mechanism whereby the effects will be obviated; such attempts have however
either proved too costly or inefficient for the purpose.
According to our present improvement to overcome the difficulty we extend for a
suitable forward distance the wooden shoe or lever that works upon and is first
operated by the key, without in any way destroying the efficiency of the said shoe,
and we prolong the damper wire to this shoe-extension instead of working it from
an arm projecting from the sticker as has been the usual arrangement. By this
means we are able to obtain an increased distance between the damper wire button
and the shoe extension which is sufficient to ensure that the button will not rest on
the operating extension of the shoe and thus even should the damper sink on the
wire, the usual derangement of the damping mechanism is effectually avoided. In
order that our invention may be more clearly understood we will describe same in
reference to the accompanying drawings. In these we have illustrated in Figs. 1
and 2 elevations of two ordinary types of "sticker-check" actions and in Fig. 3 our
improved action, and we will first describe the older types briefly in order that our
improvement and its advantages may be more readily understood.
Similar reference letters indicate similar parts.
K is the manual key by which in Fig. 1 the sticker S is directly raised and in
Fig. 2 through the medium of the interposed centred shoe R. The top of the
sticker engages a notch h in the hammer-butt which is centred to the
"flinge" from the fixed rail R2. Thus when the sticker is raised the hammer H
is "carried up" and strikes the wire W.
The damper-felt D is carried by the damper-head which is connected to the
damper-body L centred at and suitably counter-weighted at so as normally to
hold the felt against the wire. From the free end of the body L depends with an
adjusting appliance at d' the damper wire D¹ which in the actions shown in Figs. 1
and 2 passes through the "sticker-arm ”E and an operating button B is provided

page_text: above said arm. In Fig. 1 a "breast escapement" at the rear is shown at A with
an adjusting button at a acting on the said breast; in Fig. 2 a
"front escapement"
is shown at A, adjustable by the "set-off". button a acting on the escapement
arm a¹ of the sticker. In both these cases depression of the key K lifts the sticker S
and through arm E, button B, wire D and lever L raises or tends to raise the
damper D from the wire W.
In all these kinds of actions however the "lift" of the damper is very limited,
being in practise about th inch, and as before explained the space between the
sticker lever arm E and the button B is generally only ud iuch, so that when
sinkage of the felt on the wire occurs the button B falls and rests upon the sticker-
arm E.
In such case the button B cannot sink further and hence it follows that (during
playing of the piano) the constant beating of the damper-felt D against the wires
quickly causes it to become so compressed and grooved opposite to each wire as to
be out of contact with the wires altogether, and therefore no damping occurs.
The sinking also tends, by producing undue pressure on the sticker-arm E, to
draw away the sticker-head from the notch in the hammer-butt, thereby creating a
"false escapement."
"
Now as will presently be seen according to our improvement we entirely remove
the operation and control of the damper from the sticker so that whether the key be
struck forcibly or gently the sticker and the damper will always act efficiently. То
this end we provide a forward extension R1 of the sticker-shoe R and we prolong
the damper wire D¹ and pass it through same; the button B is fitted to the wire just
above the said extension R¹ and so adjusted that when the key is depressed the said
extension will engage the under side of the button B and directly push up the
damper wire D without any strain coming on the sticker and thereby causing it to
escape. By this arrangement a considerable lift can be obtained serving to
effectually remove the felt from the wire W so that the full vibration of the wire is
insured; and since the sticker is unaffected no "false escapement can occur; also
even if the felt sinks on to the wire or becomes compressed, the button B cannot
rest on arm R¹ because the space which is provided by our improvement between
the button B and arm R¹ is so ample (being about ths of an inch) that the felt
could not in any circumstances sink or compress to that extent. The working face
of the shoe R is rounded off so that it gently moves or glides upon the key and thus
friction is avoided while at the same time the direct blow is retained. The arm E
is only retained in so far as it is required for the usual "check" shown at C. The
advantages of the above described improved action are manifold. The blow is
transmitted direct from the key with a front "set off" or escapement action; no
"false escapement" being possible and therefore a better" repetition" is obtained,
no "riders" or "carriages" are required, a sufficient lift for the damper is ensured
and ample space is provided between the damper-button and the operating lever
arm of the shoe-extension to allow of any sinkage of the damper-felt on the wires
without the button B resting on the arın R¹ and so the damping action is always
preserved.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is―
1. In a pianoforte action of the kind herein referred to providing the sticker-
shoe (that is worked by the key) with a forwardly extending arm and prolonging
the damper wire to same (instead of working it from a sticker arm) the operating
button being adjusted at suitable distance thereabove, whereby the control of the
damper is removed from the sticker and a sufficient range of motion is afforded to
the damper substantially as and for the purpose herein described.
2. The improved damping action for pianofortes constructed and adapted to

page_text: operate substantially in the manner and for the purposes herein described and
illustrated in Fig. 3 of the Drawings hereto annexed.
Dated this 14th day of June 1897.