Improvements relating to Automatically Played Pianos, Harmoniums, and like Instruments.
Year: 1896

page_text: Date of Application, 23rd Dec., 1896-Accepted, 17th Apr., 1897
CUMI LELE OF MOTIVATIO
Improvements relating to Automatically Played Pianos,
Harmoniums, and like Instruments.
I, HERMANN HEGELER, of the Firm of Hegeler and Ehlers, of Oldenburg, in
the Empire of Germany, Pianoforte Manufacturer, 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 :-
This invention relates to an apparatus which has for its object to effect the
certain and exact operation of the keys of pianos, harmoniums and like instruments
by pneumatic means on the operation of a perforated sheet. The arrangement for
this purpose consists essentially in connecting each key with a bellows which is
operated by the pressure of the air when a corresponding passage is placed in
communication with the atmosphere through a hole formed in the sheet of music
that is drawn past the mouth of the passage.
The
The accompanying drawing illustrates the new apparatus in one arrangement in a
diagrammatic manner. The key is operated by means of the adjustable rod z by
the bellows b the interior of which communicates with the chamber k.
chamber is provided with two valves and of which vl leads to the atmosphere,
and to the suction space s. The two valves are connected together by means
of a bent lever to in such a manner that they are caused to open and shut
alternately.
The rod of the valve v2 is fixed at its end to a diaphragm m which shuts off the
Buction space on the other side, whilst only a small hole o, leads close by it to the
space behind the diaphragm. From this space a passager leads to the music
sheet.
The operation of the apparatus is as follows-In the position of rest shown in the
figure, the pressures in front of and behind the diaphragm m are equalised by
means of the small opening o so that the weight of the bent lever wo acts to close
the valve and to press the diaphragm towards the rear. The chamber k and with
it the interior of the bellows b communicate with the atmosphere through the
opened valve v. The bottom of the bellows is depressed and the key t is at rest
while the mouth of the passager is closed by the music sheet.
When now a hole in the music sheet as it passes comes in front of the mouth of
the passage, the pressure of the atmosphere forces back the diaphragm, as the
narrow aperture o only allows of a gradual equalising of the pressure. The rod
fixed to the diaphragm throws open the valve and the bent lever w closes at the
same time the valve v. By this means the chamber k and the bellows bare
brought into communication with the suction space. The bottom of the bellows is
raised by the pressure of the air and acts to operate the key t by means of the
rod z.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is-
1. A pneumatic key-operating device for pianos, harmoniums and like instruments
characterised by the fact that each key is operated by air pressure from a bellows
the interior of which is brought into communication with a suction space when the

page_text: perforated music sheet establishes communication between a passage and the
atmosphere substantially as described.
2. In the key-operating device characterised by Claim 1, the arrangement of a
bent lever for operating in an alternate manner the valves which lead to the
atmosphere and to the suction space respectively from the box or chest that
communicates with the interior of the bellows, the arrangement being, such that a
diaphragm is designed to throw open the valve that closes the suction space when
the said diaphragm is moved by the pressure of the atmosphere substantially as
described.
3. A pneumatic. key-operating device for pianos, harmoniums and like
instruments arranged and operating substantially- as and for the purpose herein-
before described.
Dated this Zord day of December
LOGO.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents: