Improvements in Repeating Action for Pianos.
Year: 1890

page_text: Date of Application, 25th July, 1890-Accepted, 11th Oct., 1890
Improvements in Repeating Action for Pianos.
L, WALTER IBACH, of the Town of Barmen, in the German Empire, Pinno
Manufacturer, do hereby declare the nature of my said invention, and in what manner
the same is to be performed, to be particularly described and ascertained in and by the
following statement :-
My invention relates to improvements in repeating actions for grand, semigrand,
square and other similar pianos, and is based on the system according to which the
hammers are raised by a system of levers arranged at an angle to each other, and
which are so attached, that a plumb line a-i through the fulcrum of the hammer
will, in contradistinction to the actions hitherto known, lie to the rear of the fulcrum d,
thus serving to transmit the movement of the key to the lever A.
By this means the fulcrum of the main lever can be located a proportionate, distance
forward, and the member or arm B, for producing the repeating motion has an
almost vertical position and is immediately jointed to the main lever A which consider-
ably facilitates the manufacture of the mechanism in comparison with the Erard-Herz
system.
The repetition spring can also be arrested independently of the member B, and
therefore, this member B can be provided with the escapement instead of the hammer.
The jack does not in the improved action pass through a fork of the lever, but gears in
its full breadth with the main member and under the jaw of the same, whereby the
durability of the said member is greatly increased.
By applying this escapement to the repeating member, I attain the advantage that
the jack or hopper rests securely in the jaws and will not glide out when the key is
struck hard, that the jack only requires to gear slightly under the jaw and will, in
consequence of the slight movement of the repeating member, enter the jaws very
rapidly, and that the movement of the hammer is in no way impeded by friction.
By means of my improved action I attain much more power, a very ready and noiseless
escapement, a very precise repetition, and a pleasant elastic touch, the latter being still
further increased by the peculiar construction of the mechanisin which allows the
repetition spring to be made of considerable length and to be attached at the ends to
cords, thus greatly facilitating the movement of the said spring.
In the accompanying drawings,
Figure 1 is an elevation of the improved action with the parts at rost.
Figure 2 is a like elevation of the parts when the hammer has struck the wires.
Figure 3 is a longitudinal section through the centre of the action.
Figures 4 and 5 represent modified forms of the action in clevation.
Figures 6 and 7 reprosent a simplified action,-constructed on the same principle in
elevation, Figure 6 showing the parts at rest, and Figure 7 after the key has been
operated.
Figure 8 is a top view of the hopper C³.
Figure 9 is a front view of the main lever A³.

page_text: main lever runs through a slot, Figure 3, at the upper end of the lever B and through a
loop g, and has the tendency to cause the upper end of lever B to press against the
puppet E of the hammer stem; this pressure is, however, prevented, until the hammer
is released by the puppet J, which is screwed into the main lever A and runs freely
through the member or lever B. The upper end of the repetition spring F carries a
knob K clad with leather, felt, or other appropriate materials, and is at its lower end
connected to a cord L, which runs through a wire eye M, and is connected to the
adjustable hook N in the jack or hopper C, which turns on the fulcrum h. The
threaded end of the hook N is provided with the puppet P, runs through a boring in
the jack or hopper, and is screwed through the washer like plate or nut O. The
tension of the repetition spring F can be regulated by means of the puppet P.
The position of the wire eye M must be so arranged that the jack or hopper C is
drawn onto the covering Q of the jaws S whilst the piece of felt R prevents the jack
or hopper from making too long a stroke. In such case a piece of felt T of the
member B will come into contact with the tip of the jack or hopper. The standard D
is jointed to the main lever A and is, at its lower end, firmly mortised onto the key,
the movement of which is regulated by the adjustable puppet U in the rail W, to which
the levers are connected.
Care must be taken that the parts of the action can be readily adjusted and that
trifling mistakes in mounting the same will have no deleterious effect, and so that it
must be easy for the workman to produce a pleasant touch. The regulation of the
movement, the escapement, the fall of the hammer and the tension of the spring, is
accomplished in the simplest manner by means of the adjusting screws and
puppets B, X, G, P, and the power of the spring F can even be adjusted in the finished
instrument.
Through the relative positions of the fulcra a, a, e, and bearing b, to each other,
and avoiding as far as possible all friction, the wear and tour is reduced to a
minimum. Figures 4 and 5 ropresent modified forms of my improved action. The
escapement is effected hereby in opposite direction to that described with reference to
Figures 1 to 3. The repetition spring F' is not led through a slot of the member B', but
is hung to the rear side of the same by means of the loop g¹, and is at its end provided
with a puppet K, for which the screw G¹ serves as a stop, the screw G¹ being carried by
a standard Z', securely fixed to the arm which carries the main lever A', said standard
also serving as a support for the felt or other bearing Y¹ which is fixed on the stem of
the hammer.
The repetition spring F¹ is held under tension by the cord I fixed to the adjustable
threaded wire N¹, the quter end of which is bent so as to form an eye which facilitates
the manipulation of the same, whereas the smaller oyo or hook n' serves to receive the
end of the cord L₁. By turning the wire N' in either direction, the tension of the
spring can be regulated.
The cord L runs over a nose or projection O' on the forward end of the jack or
hopper, so as to press the rear ond of the latter onto the felt or other covering Q' the
stroke of the jack being limited by the clad surface R'. By means of the adjusting
screw MI arranged in the member B' under the strip of felt T' an exact regulation of
the position up to which the hammer can move when the key receives a hard stroke,
is obtained and this is of great importance for attaining a good repetition.
Figure 5 represents the same action as in Figure 4 with a modified tension device
for the repetition spring and a special spring for the jack or hopper. The tension
adjustment device consists of a wire L", in the eye of which the spring F" is hung, and
which can be adjusted by means of the puppet P. This tension device can also be so
arranged that the wire L, is provided at each end with an eye, and is at the one end
connected to the spring F, at the other end to the hook of a flexible wire fixed to the
main lever A¹¹.
In the simplified action, Figures 6 to 10, the main lever is made in the form of an
angle or bell crank lever, the member B, Figure 1, is omitted and the jack or
hopper C³ gears direct beneath the recessed part Ss of the tumbler E of the hammer,

page_text: and is also provided with an appropriate slot for the repetition spring F³, which is
attached at to the main lever A and the spring F3 presses, when the key is at rest,
on a wedge-shaped piece of felt in the slot, but when the key is depressed the said
spring will strike against a wedge-like recessed stud or projection Y* of the hammer
tumbler in consequence of the longer stroke of the jack or hopper.
The operation of the repetition spring F³ is stopped at the moment of the release-
inent or escapement by the contact of its clad puppet K³ with the head of the
adjusting screw G³ in the tumbler of the haminer. The spring F is held under
tension by the cord L³, which runs through a slot m³ of the jack or hopper C³, and is
attached to the spring wire N³ of the latter. The position of the slot is so arranged
thut through the power of the spring F acting on the jack or hopper, the head of the
latter will be pressed onto the clad surface Q." The escapement of the jack or hopper
is effected by this member itself as the adjusting puppet X³ comes in contact with the
main lever A. When the key is struck hard the tumbler of the hammer will lie with
the felted surface T on the head of the jack or hopper and prevents injury to the hammer
whilst the wire hook Z³ limits the stroke of the hammer. The distance of the hammer
from the wires is regulated by an appropriate device. The tension of the repetition
spring is regulated by bending the wire N³, and the touch of the key by means of the
adjustable puppet Us
It will be evident that in this action the regulation of the parts is greatly facilitated
by the easy access to all the adjusting puppets and the accurate and ready regulation
of the repetition springs.
In pressing down the key, the repetition spring will be partly freed from the
weight of the hammer, thus attaining a very light escapement, minimum wear and
tear of the jaw S³ and a very exact repetition. By means of the principle on which
the construction of my improved action is based, it is rendered possible to apply the
stop for the jack or hopper to the main lever, also the escapement for the jack, so that
it acts in the direction towards the head of the haniner.
The space for the repetition spring and its gear with the tumbler of the hammer, and
also for the stop screw is hereby gained, so that a perfect repetition action is attained,
the repetition spring of which is made in very simple form in order to arrest the
movement of the hammer.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. Improved actions for grand, square and other pianos, in which the hammer is
caused to strike the wires by means of a lever or member operated on by the key, and
which is so arranged that a plumb line through the axis of the hammer will be to the
rear of the fulcrum of the main lever, substantially as specified and shown.
2. In improved actions for grand, square and other pianos, the arrangement
according to which the distance of the haunner from the wires is regulated by
means of an adjusting puppet E in the tumbler or the stem of the hammer,
substantially as set forth and shown.
3. In actions for grand, square and other similar pianos, regulating the tension of
the repetition spring F by means of a cord or wire attached to the end of the spring
and by readily accessible adjusting puppets and wire hooks, Figures 1 to 3, by wires
for winding up the cord, Figures 4 and 5, or a spring wire, Figures 6 and 7,
substantially as specified and shown.
4. In actions for grand, square and other similar pianos.
a: The device for arresting the repetition spring acting on the escapement
member or lever by means of an adjusting screw, instead of arresting the
member or lever itself, substantially as specified and shown.
b:-The method of fixing the repetition spring so that the same comes into contact
with the tumbler or the adjusting screw in the same, substantially as specified
and represented in Figures 6 to 10 of the accompanying drawings.

page_text: 5. My improved action for grand, square and other similar pianos, substantially as
specified in the foregoing Specification, and illustrated in Figures 1 to 10 of the
accompanying drawings.
BREWER & SON,
Agents for the Applicant.