IMPROVEMENTS IN MECHANICAL MUSICAL INSTRUMENTS
Year: 1884

page_text: I ALFRED JULIUS BOULT of 823 High Holborn in the county of Middlesex,
Engineer do hereby declare the nature of the said invention for "IMPROVEMENTS
IN MECHANICAL MUSICAL INSTRUMENTS" (a communication from Ludwig Potthoff
and Hilmar Golf of Berlin in the German Empire) to be as follows :-
In mechanical pianos as hitherto constructed an action is employed in which the
automatic action of the hammers is effected by air pressure either by opening and
closing bellows or by up and down motion of pistons working in metal cylinders.
In this construction the pin barrel only actuates the air valves for each separate
hammer. Practice has demonstrated the inconveniences of this system and these
are chiefly that the wind chest and tubes readily become leaky and also that the
action, if the instrument is placed in a damp place, readily fails to act in con-
sequence of the quelling of the wood.
The mechanism herein described acts without air pressure simply by a com-
bination of levers which so act on the hammer action that the short movement of
the keys operated by the pin-barrel will be sufficient effectively to impell the
hammers against the strings. The construction is moreover such that the manual
key board to be played by hand is perfectly independent from the automatic
mechanism operated by turning a crank.
There is an ordinary manual key moving on a pin which is fixed in a board or
plank as usual.
The rear part of the manual key carries a lever attached to the rear part of said
key by means of a hinge. The lever is prolonged a little beyond the key and is
guided by a pin. The pin and a regulator stud or screw are placed on the rear end
of the key and when the key is depressed a block and consequently a lifter are
operated and the hammer action rendered operative as the lever rests on the
regulator stud or screw and is compelled to participate in the movement of the
key. A rail limits the rise of the end of the key or of the lever. This action is
for playing in the usual way.
The action for the pin barrel is underneath the manual key board and the hinges
on which work the levers for transmitting motion to the hammers are fixed on
A

page_text: the under side of the board or plank which forms the bottom of the manual
key board.
Below the said board or plank, by which as stated the greater portion of the
second action for operating the hammers by the pin barrel is supported, a second
board or frame is placed on which are mounted the other parts of the lever
arrangement and the keys which are raised and lowered by the action of the pins
on the barrel.
The keys in this second key board form levers and their forward lid is fitted
as is usual in barrel organs, with a striking pin upon which the pins on the barrel
act. These keys are suitably fulcrumed and in their position of rest bear at their
rear ends against adjustable regulator screws or studs. Springs bearing by one
end against these keys by the other against the plank or board from which the
same are hung have for their object to balance the weight of the lever arrange-
ment yet to be described so that the hammers may strike with precision.
When one of the last named keys is raised by one of the pins on the barrels the
continuation or rear end of the key presses upon a small double lever which is
suitably pivoted and the double lever raises a one armed lever fulcrumed at
its end.
On the one armed lever a jack or short lifting rod is adjustably fixed; when.
said lever is raised this jack raises a likewise one armed lever placed on the upper
side of the second key board, the last named lever having its fulcrum at its rear
end whilst its front end raises another lever also fulcrumed at its end (suspended
from the plank whereon the manual key board rests) This lever transmits its
.motion directly to a two armed lever (suspended on the key board plank) having
at its end a small stud or head adjustable by means of a screw and-bearing upon
a two armed lever.
The two armed lever last referred to is likewise pivotally suspended from the
plank on which the upper key board rests and one arm thereof is made in two
parts so that the effect of this action may as far as possible resemble the elastic
"touch" on the manual key board.
To effect this a loose part of the two armed lever just referred to is attached to
the arm of the latter by two stout strips of leather or springy metal only; so
that, if the lever is thrown up too forcibly a slight amount of flexure may be
possible. On the rear part of the said lever rests a jack or lifting rod secured
by a pin against lateral displacement. The top of the jack carries an adjustable
'stud or head.
The head of this jack acts directly on the end of the lever herein above described
as attached to and projecting beyond the manual key and said jack works in
suitable guide blocks.
By the lever arrangement' just described the short stroke or movement of the
key in the second key board is so altered that a strong but nevertheless elastic
_ impact of the hammer is effected in such a manner that the jack (connected with
the second key board) lifts the lever which actuates the hammers (but without
affecting the manual keys) by raising the lifter, the latter acting in the usual
manner.
"
The rotation of the pin barrel is effected in the usual way by a worm or endless
screw on a spindle rotated by a hand wheel or crank or otherwise.
The action of the hammers is that usually employed and therefore calls for no
further description.

page_text: provements in mechanical musical instruments.
I ALFRED JULIUS BOULT of 323 High Holborn in the county of Middlesex
Engineer, do hereby declare the nature of this invention (a communication from
Ludwig Potthoff and Helmer Golf of Berlin, in the German Empire) and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
--
In mechanical pianos as hitherto constructed an action is employed in which
the automatic action of the hammers is effected by air pressure either by opening
and closing bellows or by up and down motion of pistons working in metal
cylinders. In this construction the pin barrel only actuates the air valves for
each separate hammer. Practice has demonstrated the inconveniences of this
system and these are chiefly that the wind chest and tubes readily become leaky
and also that the action, if the instrument is placed in a damp place, readily fails
to act in consequence of the quelling of the wood,
The mechanism herein described acts without air pressure simply by a com-
bination of levers which so act on the hammer action that the short movement of
the keys operated by the pin barrel will be sufficient effectually to impel the
hammers against the strings. The construction is moreover such that the manual
key board to be played by hand is perfectly independent from the automatic
mechanism operated by turning a crank. The drawing illustrates partly in section
and partly in elevation, the employment of the lever mechanism the dotted lines
showing the position at the moment at which the hammer strikes the full lines
showing the position of rest.
A is an ordinary manual key moving on the pin a which is fixed in the board
or plank B.
The rear part of the manual key A carries a lever C attached to the rear part
of said key by means of the hinge c. The lever C is prolonged a little beyond the
key and is guided by a pin d. The pin d and a regulator stude are placed on
the rear end of the key A and when the key is depressed the block f and con-
sequently the lifter D are operated and the hammer action rendered operative as
the lever C rests on the regulator stud or screw and is compelled to participate in
the movement of the key. A rail E limits the rise of the end of the key A or
of the lever C. This action is for playing in the usual way.
The action for the pin barrel is underneath the manual key board and the hinges
on which work the levers for transmitting motion to the hammers are fixed on
the underside of the board or plank F which forms the bottom of the manual
key board.
Below the said board or plank F, by which as stated the greater portion of the
second action for operating the hammers by the pin barrel is supported, a second
board or frame H is placed on which are mounted the other parts of the lever
arrangement and the keys J which are raised and lowered by the action of the
pins on the barrel W.
The keys J in this second key board form levers and their forward end is fitted
as is usual in barrel organs, with a striking pin g upon which the pins on the

page_text: barrel act as levers. These keys are fulcrumed at h and in their position of rest
bear at their rear ends against the adjustable regulator screws or studs i as will
be seen in the drawing. Springs & bearing by one end against these keys by the
other against the plank or board H from which the same are hung have for their
object to balance the weight of the lever arrangement yet to be described so that
the hammers may strike with precision.
Then one of the last named keys J is raised by one of the pins on the barrel W
the continuation or rear end of the key presses upon a small double lever L
suitably pivoted at n and the double lever raises a one armed lever P fulcrumed
at its end in o.
On the one armed lever P a jack or short lifting rod p is adjustably fixed; when
said lever is raised this jack raises a likewise one armed lever q placed on the
upper side of the second key-board, the last named lever Q having its fulcrum at
its rear end in q whilst its front end raises another lever R also fulcrumed at its
end (suspended from the plank whereon the manual keyboard rests). This
lever R transmits its motion directly to a two armed lever S (suspended at 8 on
the key-board plank) having at its end a small stud or head t adjustable by means
of a screw t and bearing upon a two armed lever T.
The two armed lever T last referred to is likewise pivotally suspended from the
plank on which the upper keyboard rests and one arm thereof is made in two
parts so that the effect of this action may as far as possible resemble the elastic
ir touch on the manual keyboard.
"
To effect this a loose part V of the two armed lever T just referred to is attached
to the arm of the latter by two stout strips of leather ww only so that if the
lever is thrown up too forcibly a slight amount of flexure may be possible. On
the rear part V of the said lever T rests a jack or lifting rod Y secured by a
pin X against lateral displacement. The top of the jack carries an adjustable.
stud or head.
-
The head of this jack acts directly on the end of the lever C herein above
described as attached to and projecting beyond the manual key A, and said jack
works in suitable guide blocks.
By the lever arrangement just described the short stroke or movement of the
key J in the second key board is so altered that a strong but nevertheless elastic
impact of the hammer is effected in such a manner that the jack Y (connected
with the second keyboard) lifts the lever C which actuates the hammers (but
without affecting the manual keys) by raising the lifter D, the latter acting in the
usual inanner.
The rotation of the pin barrel W is effected in the usual way by a worm or
endless screw a¹ on a spindle b¹ rotated by a hand wheel or crank.
The action of the hammers is that usually employed and therefore calls for no
further description.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to
me by my foreign correspondent I declare that what I claim is
1. A mechanism for automatically actuating the hammers by means of the
pin barrel of a mechanical or automatic pianoforte, the essential characteristic
feature whereof is that no pneumatic arrangement is employed but that a com-
bination of levers causes the transmission of the movements of the key J to a
lever Q which raises a lever C fixed on the key A of the manual keyboard thus
raising the hopper or lifter D of the usual construction.
2. The general arrangement of the mechanism mentioned in claim 1 as shown
in the drawings consisting of the combination of simple and two armed levers
L. P. Q. R. S. T. operated by key J substantially as specified..
3. The employment of the adjustable hopper or lifter p on the lever P for trans-
mitting motion to the lever Q.

page_text: 4. The employment of spring ke for balancing the weight of the lever arrange-
ment for the purpose of imparting lightness of " touch" to the mechanism.
5. The construction of the double lever T according to which an extension V is
connected therewith by means of strips of leather or of thin metal ww the hopper
or lifter Y for actuating the hammers resting on said extension so as to make the
impact of the latter as nearly as possible like the elastic "touch" of the manual
key A.
NAAR