A New and Improved Pneumatic Device for Mechanically Operating the Keys in Pianos, Harmoniums, and similar Instruments.
Year: 1890

page_text: Date of Application, 17th Apr., 1890
Complete Specification Left, 16th Jan., 1891-4ccepted, 17th Apr., 1891
PROVISIONAL SPECIFICATION.
A New and Improved Pneumatic Device for Mechanically Operating
the Keys in Pianos, Harmoniums, and similar Instruments.
We, AUGUST ZEITLER, Piano Manufacturer, and Joux COCCHI, Organ
Builder, both of Berlin, in the Empire of Germany, do hereby declare the nature
of this invention to be as follows:
This invention relates to keyed instruments, as pianos, harmoniums and the like,
and such mechanical musical instruments as are operated by pull or pressure, and
has for its purpose to provide an improved separate contrivance for playing pieces
of music by mechanically working the keys of such instruments.
The drawbacks inherent to devices hitherto employed to attain the above end
principally consist in the particular transformations of the instruments necessitated
to allow the said devices to be suited thereto, the latter being independently formed
as a whole and therefore requiring a certain preliminary knowledge for their
application. Moreover the separate nature of the device involves a hard relative
contact and action of the constituent parts of the mechanism and some difficulty in
re-adjusting the instrument from mechanical playing to playing by hand and rice
rers.
The inconveniences referred to are intended to be obviated in the improved
contrivance. The instrument does not undergo any alteration of shape, while the
mechanical device is engaged or disengaged by a simple manual movement and no
preparatory knowledge is required for the mechanical use of the instrument, which
The nature
can be at once reversed from the one mode of playing into the other.
of the pneumatically produced movement of the mechanism precludes almost any
friction and thereby allows of an elastic play as if executed by hand..
A vertical covering board provided below the horizontal main frame of the
instrument is revoluble about pivots lodged in the sides thereof. The operating
mechanism is so attached to said covering board as to allow only the lever
mechanism, which operates feeding bellow's placed in the rear of the instrument, and
the stop levers with the music sheet action to be visible from outside. Within the
instrument however are situated the said lever bellows with feeding channel and
pressure channel, to which channels they are attached alternately at top and bottom
for the upper and lower keys for the purpose of allowing one and the same space to
be utilized for cach pair of these bellows. The instrument further encloses the
working bellows situated in its front portion like the regulating bellows with the
requisite communicating channels between each other and to the suction channel of
the feeding bellows, and the stop levers with their connecting action with the shafts
of the operating device and thence with the waste pallets.
The levers operating the feeding bellows are connected with the keys of the
instrument by means of two-armed levers having their fulcrum on a bar provided
underneath the horizontal main frame of the instrument and of vertical rods connecting
said two-armed levers with the keys; the stop levers with the music sheet action..
which is operated by a handle provided outside the instrument and also actuates
the working bellows, occupy a vertical position to the breadth of the instrument,
thereby necessitating the above mentioned connection between the stop levers and
waste pallets.
To operate the mechanism, the covering board is changed from its vertical or
inoperative position into its horizontal position, in which is maintained by aid of
holders or arins adapted to be released in a suitable manner from the covering board
through pressure on a knob outside, when said board is to be returned to its vertical

page_text: position. When the guard- or covering-board is in its operative position, the levers,
which operate the feeding bellows and may be one- or two-armed, pass under the
key levers above referred to. When now a mechanical music sheet is moved by
the operating device over the surface of the guard board, the following effect is
produced owing to the peculiar combination of a vertical valve with a horizontal
valve which is influenced by leaf springs, said valves being provided in the space of
the feeding bellows. As long as the catch of each stop lever is being guided under
the music sheet, the respective shaft of the operating device, through its connection
with the stop lever, occupies such a position as to cause a little collar, provided on
a rod suspended from one of the two arms of the shaft, and acting upon an arm of
an angle piece connected to the above mentioned vertical valve, to release the said
arm. Thereby the horizontal valve, yielding to the pressure of the spring referred
to, closes the respective bellows and at the same time a vertical downward pin,
integral with said valve, abuts against a collar or nut of a horizontal rod connected
to the vertical valve and opens the latter. Consequently air is allowed to enter and
pass through conduits into the exhausted bellows which thereby rise and move one
extremity of their lever upward. Thereby the respective arm of the key lever
loses its support and resumes, through the upward tendency of the key, with the
latter its inoperative position. When however the catch or hook of the stop lever,
by aid of spring action or otherwise, enters from below into a music sign or slot,
the other arm of the stop lever, which arm is connected by a rod to the second arm
of the shaft, causes the latter to he turned in the opposite sense. Consequently the
bellows is exhausted by the opening of the horizontal valve and causes the key
lever to strike the key, which is effected in a noiseless and easy manner.
Or the slots of the music sheet may actuate one-armed levers which act on angle
levers situated thereunder. The latter operate rods which, being provided on the
right and left of a series of stop levers, are connected with driving dises which,
by means of pressing rods, establish connection with valve drivers having each two
angular bends. The latter respectively co-operate with the pressing rods and valve
rods in such a manner as to cause, on the dropping of the stop lever into a slot of
the music sheet a helical spring surrounding the outward portion of the valve rod
and connected with one of said bends, to be released. Thereby clack valves
connected with the valve rod are opened, a bellows situated underneath is exhausted
and an upright rod connected with the bottom plate of the bellows and standing
with its other end below the rear portion of the key rises, thereby striking a key or
hammer or opening a playing valve as the case may be. Or the valve rod may
have a bend through which the pressing rod acts on the valves; or the pressing rod
operates a two-armed lever adapted to move the valve rod.
"
After the hook of the stop lever has passed the music slot, it is pressed down by
the advancing music sheet and the respective parts resume their normal position till
the next music slot coincides with the hook of the stop lever.
The driving plates or discs referred to may also be replaced by angle pieces.
In order to allow "piano" and "forte" passages to be produced in mechanical
playing, the music sheet is provided on one or either side with a marginal recess,
while near the edge of the sheet is situated a two-armed lever having a roller and
being connected at the other end with a rod and lever, through which is governed a
valve operating the pedal levers of the instrument, said pedal levers being so
arranged as to admit also of their use by the foot when the instrument is played by
hand.
The last mentioned disposition renders the mechanical striking-lever mechanism
detachable it is drawn out for the purpose of exchanging music sheets, and
replaced.
The operating gear which may be of any suitable construction is likewise so
arranged as to be easily detachable.
Band-shaped endless or jointed music sheets may be employed. The jointed
music sheets which we propose to use have their links so connected by means of

page_text: strips, that the extremities of the latter are laid round in one and the same direction
viz. in the direction of movement of the music sheet. This serves to favour the
wear of the sheet and allow of a smooth travel and flexion of the links.
Dated this 17th day of Anvil 1800
AUGUST ZEITLER.
JOHN COCCHI.
Per Huelser & Co.,
142, Fleet Street, London, Attorneys.
COMPLETE SPECIFICATION.
A New and Improved Pneumatic Device for Mechanically Operating
the Keys in Pianos, Harmoniums, and similar Instruments.
We, AUGUST ZEITLER, Piano Manufacturer, and JOHN COCCHI, Organ
Builder, both of Berlin, and in care of Otto Sack; of Brühl, 2, Leipzig, in the
Empire of Germany, 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 :-
The object of this invention is a device for mechanically operating the keys
in pianos, harmoniums and similar instruments, as in general in such mechanical
musical works, in which a striking can be effected by push or pressure, which is
produced by bellows being actuated by means of air suction or air pressure from
the playing mechanism, which bellows transmit their movement to keys or produce
sound in another manner.
The improved device can be so attached to existing musical instruments, that
the latter need not be altered for this purpose as is required with similar devices.
Moreover no special knowledge as to the treatment of the device is required as
the mechanisin need only be shifted to and fro for being engaged or disengaged.
The drawings hereafter referred to illustrate the improved mechanism as applied
to a piano and operating with suction air.
The said advantages of the improved contrivance are attained in the hereinafter
described manner, reference being had to the accompanying drawings, Sheets I to III
in which
Fig. 1 is a sectional front view of the improved instrument.
Fig. 2 a sectional side view thereof.
Fig. 3 a sectional plan intended to illustrate the suction bellows, the regulating
bellows and the connection of both kinds of bellows with the suction channel of
the pneumatic device,
Fig. 4 is a sectional side view of Fig. 3;
Fig. 5 is a side view of the key operating mechanism in striking action,
Fig. 6 the same in front view.
Fig. 7 the same in side view when disengaged.
Fig. 8 the front view thereto.
Fig. 9 is a sectional front view of the waste channel.
Fig. 10 the same of the channel feeding atmospheric air;
Fig. 11 is a sectional elevation, and
Fig. 12 a sectional plan of the music sheet connection.
Fig. 13 is a vertical section of the instrument with the striking lever mechanism
inserted.
Fig. 14 is a partial front view of the instrument embodied in Fig. 13, the striking
lever mechanism being shown as drawn out and allowing the operation of the
suction bellows to be understood.
Fig. 15 a horizontal section of the valve chambers along line M M Fig 13;
Fig. 16 shows the valve- and wind-box (valve chambers) with the key in action.
Fig. 17 is a longitudinal section of the striking lever mechanism,
Fig. 18 a plan thereof.

page_text: Fig. 19 is a view of the pedal valve with its regulating slide,
Fig. 20'h horizontal section along line OO Fig. 19:
Fig. 21 illustrates a valve-and wind-box in which the valves lie alternatively
above and below the wind chambers.
Fig. 22 illustrates in detail the action of the driving disks in connection with the
respective striking lever;
Figs. 23 and 24 show modifications for the valve motion.
The covering.board. A below the frame B is revoluble about the pivots d lodged
in the sides of the instrument. The operating mechanism is so attached to the said
covering side or board as to allow only the one- or two-armed levers a a', which,
according to the arrangement of the bellows D D', are connected in front or behind
with the latter, Fig, 2, and the stop levers F with the music sheet action E to be
visible from outside. Within the instrument however are situated the lever
bellows D D with the suction channels G and pressure channels H, to which
channels they are attached alternately above and below for the lower and upper
keys respectively, in order to allow one bellows' space only to be used for each
two of the latter, the working bellows J, the regulating bellows K with the
requisite channels e establishing communication between the said bellows and with
the suction channel G, and the stop levers F with their connecting action with
the shafts and thence with the waste pallets M and N. The connection of the
levers a awith the keys L L' of the instrument is established by means of double
levers lodged on the rail y below the frame B, and rods connected with the
keys and said levers, Figs. 1 to 8. Consequently the bellows D D', levers a a¹
and key levers bare distributed in the position of the keys L L' over the breadth
of the instrument; the stop levers F however with the music sheet action E, which
is operated by the handle and actuates also the working bellows J, occupy a
vertical position to the breadth of the instrument, thereby necessitating the above
mentioned connection between the stop levers F and waste pallets M and N.
To operate the mechanism, the covering board A is changed from the vertical
position Fig. 4 to the horizontal position Fig. 2, in which it is maintained by aid
of the holders k until the latter are released by a pressure on knob Fig. 1, which,
through the action of the double lever m and rod n on the one-armed lever o
causes to be pressed back and release the guard board A. When the latter
occupies the position shown in Fig. 2, the bellows levers a a¹ pass underneath the
key levers. On moving a mechanical music sheet O on the surface of A by
means of mechanism E, the following effect is produced owing to the peculiar
combination of a vertical valve N with a horizontal valve M acted upon by spring p.
As long as the catch of stop lever F is being guided under the music sheet O,
Figs. 7 and 8, the shaft, through its connection with the stop lever, is so moved
that the little ball or stop t, which is moved at a rod by the arm provided on
shaft, releases the angle arms of valve N which arm is influenced by said stop.
Thereby valve M follows the pressure of spring p and closes the bellows D or D¹
respectively, shifting at the saine time by means of connecting part and stop w
of rod, this rod against valve N. The latter opens and atmospheric air enters
through the channels H into the exhausted bellows D or D' according as the valve
acts on the channel H of the bellows D or on that of the lower bellows D¹. The
bellows rise and move the lever a or a¹ off the one or other key lever b, which, owing
to the gravity of the key, resumes with the latter its inoperative position. When
however the stop lever falls into a music sign, Figs. 5 and 6, the valve N is closed
by stop or collar t, the rod is pushed back, thereby the valve M opened and the
bellows D exhausted. Consequently the bellows lever a is raised and causes the
key lever to strike the key. Thus the horizontal valve M as well as the vertical
valve N is moved simultaneously by the action of a single stop lever in a corre-
sponding manner and the key of the instrument caused to be struck, which, owing
to the simplicity and particular disposition of the mechanism is effected in a noiseless
and easy manner.
The valve and moving contrivance may also be so devised as shewn in Figs. 13

page_text: to 18 and 21 to 24. In this arrangement, the music signs Figs. 13 to 18 actuate
one-armed levers F', which act upon angle levers c situated thereunder. The latter
operate rods q which, being provided on the right and left of the series of stop
levers Fig. 18, are connected with driving discs . These discs, which may also be
replaced by angles " Fig. 22, establish with the pressing rods and the valve
drivers the connection between the angle lever rods y and valve rods v. The
valve drivers g¹ are provided with angular bends o' and o" Figs. 13, 14 and 16. The
bend is influenced by rod b' while bend o" comes into contact with valve rod v
Fig. 16, so that, on the dropping of the stop lever into a music sign of sheet O, the
rod is shifted forward by lever c, Figs. 17 and 18 and rod 61 is drawn back.
Thereby spring p² of valve rod v is released, the latter is displaced, and the
valves M M are opened, while the air inlet valve is closed. Thereby an upward
movement of the bellows cover d¹ is effected, while by means of pressing rod ¹, the
keys L are thrown up with their rear portion, thereby striking the hammer or
producing sound in another manner, as by opening the valves M M, the exhaustion
of bellows D¹ can take place from channel H through channel G Fig. 16.
The valve drivers may however also be dispensed with and the action of the
pressing rods on the valves may be produced by supplying the valve rod v
Fig. 23 with a bend e', through which the rod b' acts on the valves M and N, or
the rod is caused to depress a double lever Fig. 24, which on the other side
engages, with valve rod by which latter arrangement the valves M and N are
acted upon in the inverse sense as in Fig. 23.
As soon as the music sign has operated, the music sheet surface depresses the
stop lever F' and thereby also the valve driving rod g is pressed back by means of
angle lever C, rod y driving disk t' and rod b', and spring is once more pressed
till the next stroke Fig. 13.
In order to allow "piano" and "forte" passages to be produced in mechanical
playing, the following device is provided. The music sheet O, Fig. 18 has on one
side or both sides a marginal recess e and near the edge of the sheet is provided a
two-armed lever having a roll and being connected with a rod and lever.
Through these latter the valve Visioperated which acts upon the pedal levers KK'
of the instrument, the said pedal levers being so arranged as to admit of their use
by the foot, while playing by hand, Figs. 13, 19 and 20.
A.s may be seen from the foregoing description the mechanical striking lever
mechanism is adapted to be detached and movable independently, it being drawn
out for the purpose of exchanging the music sheets, and replaced. When the
mechanism occupies its operative position, rod is in contact with the valve driver
bends o¹ thereby establishing the connection between the mechanical music sheet
movement and the bellows. The operating gear, shown in Figs. 13, 14 and 18
consists of pinions T T and is likewise so arranged as to be easily disengaged.
The keys of the instrument may, instead of by suctional action as here before
described, also be operated by air pressure, this requiring but a slight trans-
formation of the mechanism without affecting the peculiar simultaneous movement
of valves M N. Moreover, the surface of the guard board A being free along
the entire breadth of the instrument, bend-shaped endless or jointed music sheets
may be employed. A peculiar mode of connection illustrated by Figs. 11 and 12
is provided for music sheets of the latter description.
The contiguous ends of two music sheet links 0' 0" are so connected as to
obviate injury to the connecting parts from the movement of the music sheet.
For this purpose the links are coupled by strips P of suitable material in such a
manner, that the ends P' P" of the connecting strips P are passed upward from
below the links 0' 0" through the same and laid round on the surface of the
links in the direction of the movement of the music sheet so as to prevent friction
of the bent-round ends and disconnection of the links and to admit of a smooth
travel and bending thereof, which is likewise conducive to the attainment of the
advantages of the invention as above referred to.

page_text: Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1) A device for mechanically operating the keys in pianos, harmoniums or other
keyed instruments and for producing sounds in such other mechanical musical
works, in which the striking of the notes involves a pushing or pressing action, the
characteristic feature of said device consisting in its disposition in the guard
board A below the main frame, guard board A for the purpose of engaging or
disengaging, being made revoluble about pivots d and adapted to be maintained in
a turned-up position by aid of exchangeable holding arms, substantially as and for
the purpose set forth.
2) In the device forming the subject of Claim 1 the application of a pneumatic
wind chest with drawing and pushing bellows and the combination of a horizontal
and a vertical valve M and N for producing a joint pushing and drawing action on
a pneumatic wind chest GK which acts by suction or air pressure and by aid of
valves M and N on the bellows DD', said combination actuating, in conjunction
with the pushing levers a a², the drawing levers of the key board of a piano,
harmonium or other keyed instrument, substantially as illustrated and described.
3) For the purpose of producing the effect referred to in Claim 2), the
combination whereby the striking levers F' operate on the loose valve driving
rod g', which is acted upon simultaneously with valve rod
means of angle levers c, rod g, driving disk t-or, in
pieces t, and rod, or direct through either the bend
double lever w', while the bellows D or D' produce
direct by means of rods h', substantially as set forth.
the
by spring p¹ either by
lieu of the latter, angle
or valve rod v or the
striking of the keys L
4) In the pneumatically operated keyed instrument referred to in Claims 1 to 3
the application for the purpose of allowing "forte" and "piano" passages to be
mechanically produced in playing, of a lever i which co-operates with recesses e
provided in the music sheet O Fig. 18 and actuates a valve V that moves the
pedal levers K' K" of the instrument, Fig. 13, substantially as set forth.
5) In the device torming the subject of Claims 1 to 4, the mode-where jointed
music sheets are employed-of connecting the links O' O" by means of strips P,
the two extremities Pi P" of which are secured to, and made to overlap, the
music sheet on the same side in the direction of movement, substantially as and for
the purpose set forth.
LAU
CT 1001
νιναν
AUGUST ZETTLER,
JOHN COCCHI.
By Huelser & Co.,
Temple Chambers, London, their Agents.