IMPROVEMENTS IN THE MECHANISM OF PIANOFORTES
Year: 1877

page_text: LETTERS PATENT to Jean Schwander and Joseph Herrburger, both of 10, Rue
de la Fidélité, Paris, in the Republic of France, Pianoforte Makers, for the
Invention of "IMPROVEMENTS IN THE MECHANISM OF PIANOFORTES."
Sealed the 24th May 1878, and dated the 28th November 1877.
PROVISIONAL SPECIFICATION left by the said Jean Schwander and Joseph
Herrburger at the Office of the Commissioners of Patents on the 28th
November 1877.
JEAN SCHWANDER and JOSEPH HERRBURGER, both of 10, Rue de la Fidélité,
Paris, in the Republic of France, Pianoforte Makers. " IMPROVEMENTS IN THE
MECHANISM OF PIANOFORTES."
This Invention consists in a new arrangement of the hammer striking the strings.
The hammer butt or nut, to which is adapted the axis on which the hammer
oscillates, and which until now terminated at this point, is continued or extended
on the other side, and its extremity comes in contact with the piece called the.
check. The escapement is also provided with a small return angle or end in con-
nection with the regulating pin or screw placed in a support on the right and in
front. The combination of this new projecting part of the hammer butt of the
escapement and the check allows the pianist to repeat the note at any point to
which the key may be depressed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Jean Schwander and Joseph Herrburger in the Great Seal Patent
Office on the 27th May 1878.
JEAN SCHWANDER and JOSEPH HERRBURGER, both of 10, Rue de la Fidélité,
Paris, in the Republic of France, Pianoforte Makers. "IMPROVEMENTS IN THE
MECHANISM OF PIANOFORTES."
Our improvements in the mechanism of pianofortes consist in the means of
insuring a perfect repetition, The hammer butt or nut, to which is adapted the
axis on. which the hammer oscillates, and which until now terminated at this point,
is continued or extended on the other side, and its extremity comes in contact with
the piece called the check. The escapement is also provided with a small return
angle or end in connection with the regulating pin or screw placed in a support on
the right and in front.
But, in order to make our Invention better understood we will now proceed to
describe the same by reference to the accompanying Drawing, in which,-
Figure 1 shews a side view of the mechanism as applied to one piano string, the
others being similar.
Figure 2 is a view of the same mechanism with a modification of the method of
regulation.
Figure 3 is a view shewing the application of our improvements to grand
pianos.
A is the hammer butt or nut, oscillating as usual on an axis, the upper part of
the hammer not being shewn in the Drawing; A¹ is a prolongation of the hammer
butt or nut; C is the escapement; D, the check; × is the escapement button;
and C, the regulating screw or pin mounted on the support S1 carried by the tail
of the check D. When the key has raised the escapement C, and caused the
hammer to move as usual, the relative position of the prolongation A¹ of the
hammer butt or nut of the check D and of the button x is such that the hammer
can recommence to strike, however small may be the play of the key which
remains, whereby a perfect repetition is thus insured.
The pieces and C" screw into their supports, and as the knobs or rings at
their ends are easy to get at, the regulation of the mechanism can be effected.
without removing any of the parts.
Figure 2 shews the same system, in which the check and mode of regulation
alone are different. In this arrangement we have placed the tail of the check,
at x, through which we pass a screw, which can be easily turned by hand or other-
wise. An escapement button C, placed screwwise or frictionwise in any suitable'
support, and easily turned by hand, serves to limit at will the play of the tail N of
the escapement C.
Figure 3 shews the application of our improvements to grand pianos, in which
case the parts are arranged as follows:-A, C, shew the hammer butt or nut
and its prolongation; D is the check, and E the spring of the same; H, regu-
lating screw. The play of the parts is facilitated by the spring I, K, which spring
being jointed at M presses in opposite directions on the axis J of the piece N, and
on the axis K of the tail G of the escapement F.
Having thus described our Invention, and the manner of performing the same,
what we claim is,-
Firstly. The prolongation A¹ of the hammer butt or nut A from its axis of
rotation.
Secondly. The form and position respectively of the escapement C, of the
check D, and of the method of regulation of the pieces × and C¹¹.

page_text: Thirdly. The combination of the prolongation A¹ of the hammer butt or nut A
with the check D and escapement C.
In witness whereof, we, the said Jean Schwander and Joseph Herrburger,
have hereunto set our hands and seals, this Twentieth day of May, in the
year of our Lord One thousand eight hundred and seventy-eight.
JEAN SCHWANDER. (L.S.)
J. HERRBURGER.
(L.S.)