IMPROVEMENTS IN "ACTIONS" FOR PIANO- FORTES
Year: 1882

page_text: LETTERS PATENT to Thomas Croome Dauncey of Stroud in the County of
Gloucester for an Invention of IMPROVEMENTS IN "ACTIONS" FOR PIANO-
FORTES.
PROVISIONAL SPECIFICATION left by the said Thomas Croome Dauncey
at the Office of the Commissioners of Patents on the 1st December 1882.
THOMAS CROOME DAUNCEY of Stroud in the County of Gloucester
MENTS IN ACTIONS FOR PIANOFORTES
"
"
IMPROVE-
The chief object of this invention is to do away with the friction and its evil
results usually inseparable from pianoforte actions. In ordinary actions the end
of the hopper rests against the hammer-butt and forces it up when the blow is
struck but the parts of contact have to be covered with leather or cloth and
carefully blackleaded; but a little damp or even change of temperature quickly
upsets this delicate arrangement and satisfactory repetition is not obtained until
the action has been regulated again There are also other rubbing surfaces which
bave to be leaded.
Now I dispense with these frictional surfaces in the following manner-Instead
of letting the end of the hopper rub against the hammer-butt, I joint a piece on to
the end of the hopper and joint its other end to the hammer-butt employing an
ordinary screw button to regulate the angle at which it lies the joints or centres
are bushed with cloth in the usual manner-
-Upon the side of the hopper is a
projection or check covered with leather or cloth which strikes against the check
rail to prevent the hammer head returning too far from the string. There is'
another projection or foot at the bottom of the hopper which is leathered or clothed
as before and rests upon a spring one end of which is fastened to the lever and its
other or free end comes in contact with a suitable rail or stop which prevents it
following the foot too far when the note is struck. The working is practically
similar to that of the ordinary check-actions excepting that the friction surfaces
are done away with. The action as described above is suitable for upright piano-
fortes but suitable modifications can of course be made to suit other forms of
nstruments or special circumstances.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Croome Dauncey in the Great Seal Patent Office on the
1st June 1883.
THOMAS CROOME DAUNCEY of Stroud in the County of Gloucester
MENTS IN 'ACTIONS' FOR PIANOFORTES
"
"IMPROVE-
The chief object of this invention is to do away with the friction and its evil
results usually inseparable from pianoforte actions. In ordinary actions the end of
the hopper rests against the hammer-butt and forces it up when the blow is struck,
but the parts of contact have to be covered with leather or cloth and carefully
black leaded; but a little damp or even change of temperature quickly upsets this
delicate arrangement and satisfactory repetition is not obtained until the action
has been obtained again. There are also other rubbing surfaces which have to be
leaded.
Instead
Now I dispense with these frictional surfaces in the following manner.
of letting the end of the hopper rub against the hammer-butt, I joint a piece on
the end of the hopper and joint its other end to the hammer-butt employing an
ordinary screw button to regulate the angle at which it lies. The joints or centres
are bushed with cloth in the usual manner Upon the side of the hopper is a
projection or check covered with leather or cloth which strikes against the check
rail to prevent the bammer head returning too far from the string. There is
another projection or foot at the bottom of the hopper which is leathered or clothed
as before and rests upon a spring one end of which is fastened to the lever and its
other or free end comes in contact with a suitable rail or stop which prevents it
following the foot two far when the note is struck. The working is practically
similar to that of the ordinary check-actions excepting that the friction surfaces
are done away with. The action as described above is suitable for upright piano-
fortes but suitable modifications can of course be made to suit other forms of
instruments or special circumstances
Reference being had to the accompanying drawings in which like letters of
reference represent like parts. Figure 1 is an elevation shewing the ordinary con-
struction. Figure 2 a like view of my improvement. Figures 3 and 4 modified
forms of the same
In the ordinary form in Figure 1 it will be seen that the hammer-butt A is
forced up when the key is depressed by the end B' of the hopper B which rests
against the angle A¹ of the butt and frees itself by the regulating screw B³ which
is attached to the hopper B coming in contact with the escapement rail B. This
escapement rail B being oblique forces the hopper B and B' away from the angle A¹
just at the moment of striking the string allowing the hammer to rebound against
the check B. This arrangement necessarily causes great friction and is very liable
to get out of order.
In Figure 2 is shewn a method which dispenses with the objectionable features
above indicated the hammer-butt A has a fixed projection C to which is jointed
by an ordinary bushed joint the intermediate piece D whose other end is similarly
jointed to the hopper B. as the hopper B is raised by the depression of the key
the intermediate piece D carries the push on to the hammer-butt A and the blow
is imparted to the string in the usual manner, the adjustable button E serving to
regulate the dis-engagement as will be well understood by those conversant with
the art, and assisted by the action of the spring F upon the adjustable button Go
the hopper B.
Upon hopper B is a fixed extension H upon which presses the spring I thu
keeping the hopper pressed well inwards so that the intermediate piece D bear

page_text: against the button E and the thrust is necessarily conveyed to the hammer-butt as
described.
When the key is being depressed and the hopper rising, the spring I follows it
up keeping the hopper B pressed against button E until the end of spring I reaches
another adjustable button K which stops its progress so that as the hopper rises
higher the extension H is clear of the spring I and at the proper moment the hopper
is free to fly back leaving the hammer disengaged as is shewn in the dotted lines
in Figure 2.
The motion of the key L is transmitted to the hopper B by the sticker M and
lever N in the usual manner
The
The difference in figure 3 consists in using a divided hammer-butt A A* the
two portions being connected by the piece of cloth or equivalent A³
hopper B is jointed to the loose portion A* and the action is the same as in
Figure 2
In Figure 4 is shown a simple form of check. When the hammer has struck the
string the rebounding forces the projection O against the check rail P thereby
holding the parts A D B firmly until the key is released when the hopper B returns
to its former position ready for another blow. The projection O and the check
rail P being at a different angle the projection O wedges itself as it were against P
producing the same result as the ordinary French check shewn in Figures 2 and 1
Having now described my invention and the method of performing the same I
wish it to be understood that I claim
First. The combination with the hopper B of the intermediate piece D
substantially as and for the purposes set forth and shown.
Second. The divided haminer-butt A. A in combination with the hopper B
substantially as described and illustrated in Figure 3 of the accompanying
drawings.
Third. The combination with the hopper B of the fixed extension H spring I
and adjustable button K whereby the hopper is constantly pressed forwards until
the disengagement is required when the pressure is removed substantially as
described and illustrated.
In witness whereof I the said Thomas Croome Dauncey have hereunto set
my hand and seal this thirtieth day of May in the year of our Lord one
thousand eight hundred and eighty three.
THOMAS CROOME DAUNCEY (L.S.)