Year: 1887

page_text: Date of Application, 10th Feb., 1887
Complete Left, 9th Dec., 1887
Complete Accepted, 13th Jan., 1888
I, ROBERT DAVIDSON of No. 2 West Newington Place, Edinburgh, in the County
of Midlothian, North Britain, Professor of Music do hereby declare the nature of this
invention to be as follows:-
This Invention, which relates to improvements in piano-fortes, has for its object to
increase the variety of tone in this class of musical instrument.
The Invention consists in applying to the piano-forte a series of stops actuated by
one, two, three or more pedals, which are pressed upon the cords of the instrument,
and their position is such that when pressed upon the cords they virtually divide each
cord into halves, so that the length of cord vibrating and sounding when struck by
the hammer is one half of the length of cord which vibrates in the normal condition,
and the tone or pitch of the sound is thereby raised to an octave higher, besides
being softened in its quality.
The pedals as they are depressed move a set of levers which are moveable pivotwise
about the centre of their lengths, and at one end of which are the stops, these being
made adjustable by screws or their equivalents. The other ends of these levers aro
also provided with adjustments, and these being presssed by the pedal action against
the dampers cause the stops to be moved into contact with the cords.
J. H. JOHNSON, DAY & JOHNSON,
115, St. Vincent Street, Glasgow,
Petitioner's Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Pianofortes.
1, ROBERT DAVIDSON of No. 2 West Newington Place, Edinburgh, in the County
of Midlothian, North Britain, Professor of Music do hereby declare the nature of
this 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, which relates to improvements in pianofortes has for its object to
increase the variety of tone in this class of musical instruments.
My Invention consists in applying to the pianoforte a series of stops or stoppers
actuated by one, two, three or more pedals, which are pressed upon the cords of the
instrument, and their position is such that when pressed upon the cords they virtually
divide each cord into halves so that the length of wire or cord vibrating and sounding
on each side of the stop or stopper when struck by the hammer or striker of the piano-
forte is one half of the length of cord which vibrates when the wire or cord is in
the normal condition, and the tone or pitch of the sound is thereby relieved an octave
higher, besides being softened in its quality.
The pedals as they are depressed move forwards a set of levers which are again
moveable pivotwise about the centre of their lengths, and at one end of which are
the stoppers or stops, these being made adjustable to exactitude by screws or their
equivalents. The other ends of these levers are also provided with adjustments, and
tliese being pressed by the pedal action against the dampers cause the stops to be
moved into contact with the cords at the instant of a note of the pianoforte being
struck.
In order that my Invention may be properly understood and readily carried into
effect, I have appended two sheets of drawings of which Figure 1, is a plan of a
portion of a grand pianoforte constructed and shewn with my improvement attached
thereto.
Figure 2, is a longitudinal section of the principal parts of the same instrument
also illustrating the manner of applying my Invention to the said instrument.
The mechanism consists first of a broad bar A, which may be of mahogany or other
material and about an inch in thickness, which is fastened by bolts or otherwise in
any angular position horizontally to the metallic bars B, of the instrument which
resist the tension of the strings. This bar A, is furnished with a number of per-
pendicular wires to keep the levers in position also shorter wires bent nearly at right
angles to prevent the longer levers from touching the strings when they are not in
use. Secondly. A narrow bar of the same length but somewhat thinner. This bar
is placed under the former one and made to slide backwards and forwards and on the
under surface is pierced with small holes to receive the forks in which the levers are
centred. The number of these holes corresponds with that of the keys of the
instrument to which the apparatus constituting this Invention is applied.
Thirdly. A set of levers C, of different lengths and composed of the following
parts, viz-The stop or stopper a, Figure 2, which is a small piece of wood about a

page_text: quarter of an inch in thickness and of sufficient length to press upon all the strings
belonging to one key when brought into position across these strings or at right
angles to them. The under edge of the stop or stopper a, is rounded and covered
with a sufficient number of plies of fine doe leather in order to soften it (for example,
three or four such plies). The upper part of each stop or stopper is let into a slot in
the back end of each lever C, and it is long enough to admit of being moved about an
inch more or less backwards or forwards in the said slot as may be required in order
to touch the string exactly in the centre between the two bridges at each end of the
instrument.
The head of the stop or stopper a, in the aforesaid slot is furnished with a regulating
screw b, which, at its external end is made square for the purpose of being turned
by a small key. Beyond this point the screw is fastened into the centre of a narrow
slip of sheet brass which is bent over the end of the lever. The ends of the sheet
brass are rivetted into the sides of the lever, which serves the double purpose of
keeping the screw, in position and at the same time preventing the wood of which
the levers C, are formed from splitting.
There is also another screw E, on the upper surface of the lever, placed in a
vertical position which is intended to prevent the possibility of the horizontal screw b,
from turning after it has once been regulated.
The centre on which the lever C, is suspended consists of a small peg driven through
the lever at that point which will balance it so that the stops or stopper a, will not
touch the strings F. The pressure adjustment consists of a slit c, at the front end of
the levers C, the under half f, of which is jointed by a piece of strong leather and the
slit can be made wide or narrow as may be necessary by the screw which is passed
through the upper half of it. The under half of the slit is also bevilled on the lower
surface to allow it to come over the head of the damper G, when the mechanism is in
position for being operated by the performer on the instrument. The inside of the
slit is covered with doe leather to prevent noise. The fork for holding the lever are
fastened by the screws to the under surface of the under bar. These have a small
puncture half through each prong in which the centre of the lever is held and whereon
it oscillates when acted upon by the keys as herein before described. The under bar
is under the arrangement shewn on the annexed drawings, cut, into three divisions
two of which, namely those marked X, and Y, contain twelve levers with their stops
or stoppers a, hereinbefore described. The right hand division marked Z, contains
sixteen levers the third octave being completed by the pedal to which it is connected
and four more levers added to the instrument.
Fourth. The above described mechanism is brought into play by means of three
additional pedals g, h, i, shewn in plan in the detached view, Figure 3, which are
connected to the back of the under bar by arms of iron which have uprights passing
through the sounding board from below to meet them, these uprights are entered into
a fork and are kept there with a peg having a screwed nut upon it. When the pedals
are pressed down by the foot they draw the under bar containing the forks and levers
forward towards the player, which brings the stops or stoppers a, directly over the
strings at the centre of their length and the front end of the levers C, over the
damper heads G, so that when a key within the compass of the keys to which the pedal
is applied is struck the dampers will press the stoppers exactly on the middle of the
three strings belonging to the said key which causes the vibration at that point to be
at rest and divides the string into two equal parts vibrating simultaneously from that
point to each end.
The sounds produced by operating upon the strings of a pianoforte in this manner
are those which are termed "harmonics" and such as can be and are produced
hitherto upon instruments such as the violin, violincello, double bass, harp, guitar and
zither, the pianoforte standing alone hitherto, without the capability of producing
"harmonics." The sounds produced by pressing on the strings are an octave higher
in pitch than those uttered by the whole string. The left pedal draws forward the
lowest octave; the next, the middle octave, and the right the highest octave and the
sounds added above that octave.

page_text: Fifth. The pedals are constructed as follows:-They are placed in the space
between the shifting and damper pedals and are or may be made in the form of a
Prince of Wales Feather as shewn in the plan Figure 3, and situated so near to each
other, that they may be pressed together with one foot or singly as required. When
a pedal is pressed, it pulls a piece of catgut or other material which passes over three
or more pulleys j, and is then hooked to the back end of the tracker K, to which is
fastened the upright C, hereinbefore mentioned and which passes through the sounding
board L, being thence connected to the arm M, which is attached to the under bar N,
aforesaid.
The tension of the catgut or its equivalent is adjusted by a brass nut under the
pedal. When the foot is removed from the pedal, a spiral spring O, pulls the bar N,
with the levers C, back to its place, and the front ends of the levers U, remove back-
wards from off the heads of the dampers G.
The pedal tracker K, is a four sided beam of wood lying parallel with the instru-
ment and is carried in guides P. This moves forwards and returns backwards as the
foot presses or releases the pedal, the catgut or its equivalent being hooked to them.
For convenience in removing the instrument, the pedals and pulleys are so constructed
as to be taken off the instrument in one piece, and in doing this it is necessary to
disengage the catgut or its equivalent by pressing the trackers R, forward and then
unhooking the catgut or its equivalent from them. The brass screws are then removed
from below the pedals and these parts will then come away together.
On setting up the instrument care must be taken that the nuts under the pedals
are screwed until the stops or stoppers are brought to touch the exact middle of the
string, this is easily tested by putting down the pedals and striking a key holding it
down for a short time and listening whether or not the sound continues, if it does not
continue adjust the nuts a little more until the sound continues.
If the sound of any single key is not correctly produced after the pedals have been
regulated it is necessary to rectify these by slackening the screw on the back end of
the lever C, belonging to that key and then turn the horizontal screw until the proper
adjustment is effected. When this is effected, it is necessary to tighten the upright
screw after regulating the horizontal one and the horizontal screws are so fitted that
the adjustment of the stop or stoppers may not alter. When this adjustment is being
made it is necessary to keep the pedals quite down otherwise the stops or stoppers a,
cannot be brought to their places. To regulate the amount of pressure of a stop or
stopper on the strings, put down the pedals and turn the screw on the front end of
the lever until the sound of the octave is that of the octave above the sound produced
by the keys when the pianoforte is in its normal condition.
Should the screw not be sufficiently turned the effect will be that the lower sound
will be heard before that of the octave, in consequence of the slit not being wide
enough.
Perpendicular wires are driven into the under surface of the upper bar A, to keep
the levers C, in their position, and there are also other wires made in the form of
staples whose function is to keep the longer levers C, off the strings, when the pedals
are unemployed.
When the pianoforte so described is properly adjusted a very little study enables a
good pianist to produce considerable varieties of effect, for example by performing
passages which lie within the compass of the three octaves and a major third reckoning
from the second C, in the bass which is in unison with the fourth string of the
violincello or in other words the tenth long key counting from the left hand of the
key board of a modern seven octave pianoforte. Such passages will be better when
played in a legato and singing style with all three pedals firmly pressed down and
employing the damper pedal to sustain long notes at terminations, and if a change of
harmony should occur a further or repeated application of this pedal must be made.
Another effect may be produced by performing a similar passage or melody with
the addition of the shifting pedal, and employing a smorzando touch not allowing the
fingers to leave the keys.
Another effect is obtained by playing a melody on the treble notes while an

page_text: arpeggio is executed by the left hand keeping down one or two of the pedals with the
left foot while the right foot is applied to the damper pedal as before directed.
A stick is suspended above the shifting pedal as is done with the swell pedal of an
organ in order to keep the stop or stoppers down as long as required when it is
released by the toe. Another effect is produced by performing a harmonised melody
by using the harmonic pedals (say in three parts) at the same time playing a florid
accompaniment in the treble. When the cords of the harmony are rather wider than
can conveniently be played the hand must spring the large cords while using the
damper pedal to sustain them. Another effect is produced by executing a melody
within the compass of a major seventh reckoning from the lowest key of the twelve,
acted upon by the pedal pressed down, playing it with the thumb of the left hand, and
substituting one finger for another on the same key, when a skip occurs between the
last key struck and the following one. Along with this melody a bass may be played
under it by springing the large intervals between it and the melody as quickly as
possible, using the damper pedal to sustain it as before directed while the right hand
accompanys in a florid manner as before in single or double notes in the treble.
The shifting pedal may be used for all these ways of playing provided that the
music is intended to be piano.
It is to be understood that although the Inventor has in the preceding specification
and appended drawings, illustrated his Invention as applied to a grand pianoforte
wherein the levers for actuating the stoppers and the apparatus for operating them
are arranged horizontally, he does not by having so illustrated his Invention thereby
imply that it is applicable only to pianofortes in which the sounding-board and cords
or strings are horizontal and it is here expressly stated that the said Invention is
equally applicable to that class of piano in which the sounding-board and string or
cords are upright.
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 :-
1st. The production in pianofortes of the variations of sound herein referred to by
the division of the strings or cords into half of their normal lengths by causing a
stop or stoppers to be pressed upon the strings or cords at the exact half distance
between the points of attachments to the bridges so that cach half of the string
vibrates in synchonsm into half of its normal length substantially as hereinbefore
described and shewn.
2nd. The mechanical arrangements or the mechanical equivalents of such arrange-
ment whereby the levers C, are brought with their front ends into contact with the
dampers G, so that when operated by the keyboard the dampers G, lift the front ends
of the levers C, and depress the back ends of the said levers C, so as to cause the
stop or stoppers a, to press upon and divide the string or cords into two equal halves,
substantially as herein before described and shewn upon the annexed drawings.
3rd. The arrangement of the additional pedals, together with the trackers K, for
moving the sets of levers C, backwards and forwards substantially as hereinbefore
described and shewn on the annexed drawings.
Dated this 8th day of December 1887
ST. JOHN V. DAY,
115, St. Vincent Street, Glasgow,
Applicant's Agent.