IMPROVEMENTS IN PIANOFORTE ACTIONS
Year: 1878

page_text: LETTERS PATENT to Carl Kesseler, of 63, Mohrenstrasse, Berlin, W., in the
Empire of Germany, Civil Engineer and Patent Solicitor, for the Invention
of "IMPROVEMENTS IN PIANOFORTE ACTIONS." A communication from Eduard
Westermayer, Pianoforte Maker, of Berlin, in the Empire of Germany.
Sealed the 13th June 1879, and dated the 27th December 1878.
PROVISIONAL SPECIFICATION left by the said Carl Kesseler at the Office
of the Commissioners of Patents on the 27th December 1878.
CARL KESSELER, of 63, Mohrenstrasse, Berlin, W., in the Empire of Germany,
Civil Engineer and Patent Solicitor. "IMPROVEMENTS IN PIANOFORTE ACTIONS."
A communication from Eduard Westermayer, Pianoforte Maker, of Berlin, in the
Empire of Germany.
The improved action differs from similar constructions from Erard, Steinweg,
and others chiefly by the general arrangement of the various parts, which allows it
to be easily taken to pieces. The facility in taking the action to pieces results
from arranging the hammers and the pushers respectively on separate bars. After
removing the hammer bar with the hammers the bar with the pushers can be lifted
out, while the key with the repetition lever is drawn out from the front. The
independence of these three systems from one another allows of an adjustment of
the various parts separately, or when placed together without any difficulty. The
lifting of the hammer is effected by two pushers (instead of one only), of which the
former acts as auxiliary during the upward motion of the hammer more than the
main pusher which rests on a support. Thus not only an easy disengagement is
effected but also the main pusher speedily replaced into its original position on the

page_text: support. By the application of the main pusher the working surface of the support
is spared, because the disengagement of the main pusher takes place at a moment
when the latter has already been slightly lifted up from it. This lifting motion
results in the different distance of the points of application of the pushers from the
point of contact of the key. The ease of touch and high capacity for repetition
result already from the device mentioned, but are also further influenced by
balancing the weight of the pushers with a counterweight with lead or any other
metal which is applied on the lever. This arrangement makes it possible to give
the spring on the repetition lever a far smaller tension, because it has no longer the
weight of the pushers to carry.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Kesseler in the Great Seal Patent Office on the 17th June
1879.
CARL KESSELER, of 63, Mohrenstrasse, Berlin, W., in the Empire of Germany,
Civil Engineer and Patent Solicitor. "IMPROVEMENTS IN PIANOFORTE ACTIONS."
A communication from Eduard Westermayer, Pianoforte Maker, of Berlin, in the
Empire of Germany.
The action as illustrated by the adjoined Drawing differs from similar construc-
tions from Erard, Steinweg, and others, chiefly by the general arrangement of the
various parts, which allows it to be easily taken to pieces. The advantages in the
constructive details will be pointed out in describing the mechanism. The facility
in taking the action to pieces results from arranging the hammers and the pushers
respectively on separate bars. After removing the hammer bar a with the hammers
the bar b with the pushers can be lifted out, while the key with the repetition
lever c is drawn out from the front. The independence of these three systems from
one another allows of an adjustment of the various parts separately or when placed
together without any difficulty. In the construction of details the present action
differs from that which has formerly been patented by the inventor in Prussia as
well as from all others by the following advantages which appear during the use of
the instrument by the artist, as well as in its increased durability:-1. The lifting
of the hammer is effected by two pushers d, d', (instead of one only), of which the
former acts as auxiliary during the upward motion of the hammer more than the
main pusher which rests on the support e. Thus not only an easy disengagement
is effected but also the main pusher speedily replaced into its original position on
the support. 2. By the application of the auxiliary pusher the working surface of
the support e is spared, because the disengagement of the main pusher takes place
at a moment where the latter has already been slightly lifted up from it. This
lifting motion results from the different distance of the points of application of the
pushers from the point of contact of the key. It will be seen from the Drawing
that the auxiliary pusher d' must have a larger stroke than the main pusher d, but
since both are acting on the projecting arm of the beam f, and through the block g
of the latter impart the stroke to the hammer h, it follows that during the upmotion
the auxiliary pusher d¹ alone acts upon the hammer because the main pusher is
first slightly lifted from the support e, and in the same moment its bend comes in
contact with the disengaging buffer i, thereby receiving a lateral motion which is
the greater as the point of the beam f upon which the main pusher acts moves
against the buffer. By these combined motions the main pusher is released without
friction on the support e. During the downmotion of the key the spring k effects
the return of the pusher to the original position. 3. The ease of touch and high
capacity for repetition result already form the device mentioned under (2), but are
also further influenced by balancing the weight of the pushers by the counter-
weight of lead or any other metal which is applied on the beam f. This arrange-
ment makes it possible to give the spring n on the repetition lever a far smaller
tension, because it has no longer the weight of the pushers to carry. Consequently
the resistance in touch, and especially in repetition, is much smaller, and for
repetition the mechanism follows the slightest pressure of the finger in the smallest
intervals and with perfect precision. The action is also entirely released from the
disturbing influence of a hard touch, the friction being reduced to a minimum in
consequence of the described motions and of the balancing. Claims:-1. A piano-
forte action in its general arrangement, as described and shown by the Drawings.
2. The fixing of the hammers and the pushers in pianoforte actions on separate
bars, for the purpose and in the manner as shewn and described. 3. In a pianoforte

page_text: action the auxiliary pusher d', and the beam f, and the projecting arm, substantially
as shewn and described. 4. In a pianoforte action the balancing of the weight of
the pushers by the counterweight 1, for the purpose and in the manner substantially
as shewn in the Drawings and described.
In witness whereof, I, the said Carl Kesseler, have hereunto set my hand and 5
seal, this Fourteenth day of June, A.D. 1879.