Year: 1886

page_text: I JOSEPH DELERUE of Oporto, in the Kingdom of Portugal do hereby declare
the nature of this invention to be as follows:-
This invention relates to further improvements on an invention for which
I applied for a Patent on the 22nd day of March 1886 N° 4,016 and in order to
enable the said improvements to be fully understood I will describe the same by
reference to the accompanying drawing in which figure 1 is an elevation of the
parts of the improved action and figure 2 is a part vertical section of the same.
The new check or check movement for the improved repeating pianoforte action
consists firstly of a wire F of suitable metal such as iron or copper of two to three
millimeters in diameter; it is flattened and curved at the part marked F. One of
the ends of this wire which I call the check wire is driven into a piece of covered
or lined wood A which forms the check properly so called.
The other end of the wire F near its curved part is driven firmly into the piece
of wood X jointed at O by means of a pin or axis placed in the bridge or bar S
which forms the general support of the check movement.
The piece X also receives the jack spring R, which is fixed thereto as shewn in
the drawing. The latter part of the check is formed of a screw threaded wire V
passing through the jack fork E and terminated at one of its ends by the small.
cylindrical piece of wood B of about 2 to 3 centimeters in length firmly fixed to
the said screw threaded wire and receiving at the other end the conical point of
the check wire at the point where it bears on the piece ✗ as shewn at f figure 2.
The piece A or check properly so called receives and stops the end of the hammer
(not shewn in the drawing) in its return or descent after it has struck the string.
This operation is effected with great precision by reason of the arrangement of the
check which according as the string is struck with more or less force and rapidity
gives way to a proportionate extent and supports the hammer during the time
necessary to allow the jack to again come under the butt of the hammer. It is
necessary to provide some means of adjustment for bringing the check farther
from or nearer to the hammer in order to properly fix the stopping point of the
hammer. This adjustment is effected by means of the screw threaded wire V which
has its fulcrum or bearing point on the fork E into which it is screwed and of the
piece B belonging to the wire V which it causes to bear on the piece X to give it
& movement around the axis O. The spring R not only serves to bring back the

page_text: jack D but it forces the piece ✗ to bear upon the piece B. It will therefore be
obvious that the recoil or advance movement which is communicated to it by the
Bcrew will transmit the required movement to the check A.
This arrangement of check forms a peculiar feature of my invention as it is
opposed to that which has hitherto been employed. In pianoforte actions as
hitherto made the check movement has always been placed at the right hand side
of the centre of oscillation of the hammer or under the hammer. My improved
arrangement gives the exact direction of movement of the check which is necessary
for its working properly.
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
1. The check A having its centre of movement or its movement of flexion placed
at the left hand side of the centre of oscillation of the hammer and in proximity to
the strings of the piano substantially as herein before described.
2. The piece X forming the support of the check wire substantially as herein-
before described.
3. The arrangement of the spring R serving the double purpose of bringing back
the jack and of keeping the piece X. in its normal position substantially as herein-
before described.
4. The combination of the pieces B and V forming the adjusting mechanism of my
new check movement substantially as herein before described.
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