Improvements in Pneumatic Actions or Relays for Mechanically Played Keyboard Musical Instruments.
Year: 1894

page_text: Date of Application, 15th Oct., 1894-Accepted, 17th Nov., 1894
COMPLETE SPECIFICATION.
Improvements in Pneumatic Actions or Relays for Mechanically
Played Keyboard Musical Instruments.
I, FRANZ HANKE, of 9 pt. Strassburgerstrasse Berlin, in the Empire of
Germany, Organbuilder, 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 a pneumatic action or relay for keyboard musical
instruments that are played mechanically, the said action or relay being operated
by a partial vacuum or suction instead of by compressed air. By this means the
number of mechanical elements or connecting parts between the music cylinder and
the action or relay is reduced; and what is more important a more exact and
lighter touch and a more powerful tone is obtained.
In the accompanying drawing which illustrates this invention the figure is a view
in side elevation partly in section showing the device in combination with the music
cylinder and the hammer frame of a pianoforte.
Above the cylinder A of the music mechanism, and arranged in a separate
frame B, are the playing or operating levers C which carry at their forward
ends, as usual, a playing or actuating pin D, and at the opposite end a pusher
rod E. The latter is carried by any suitable means in an air-tight manner
through the top or cover F of the air chest L, and serves to actuate the playing
valve G.
In order to regulate the upward movement of the levers C and thus also the
descent of the valves G, there is provided for each lever C a regulating or
adjusting screw I above the rear ends of the levers C in a separate bar H carried
by the frame B.
The action or relay proper consists of the air passage K (branching off from the
main air passage) and of the air chest L in which latter the valves G are arranged
and separated from each other by air tight partitions. The action or relay further
comprises the countervalves M which are situated on the upper side or cover F of
the air chest L and connected with the aforesaid valves G and normally kept
opened by means of an adjustable rod m as shown, and it also comprises the
actuating bellows N which are arranged on the underside of the air chest L, and
are connected by means of pusher rods P with the actuating levers of the hammer
mechanism.
When the cylinder A is inserted perpendicularly to the keyboard instead of
horizontally as shown the connection between the levers C and the pusher rods E
is effected by means of bell-cranked levers and rods. In this case the said levers
and rods are made of sheet brass and set close to one another.
The mode of operation is as follows:-The air passage K is being constantly
exhausted by the main air chamber which is provided for operating the action or
relay, so that a partial vacuum is produced in the passage K.
When the valve G
is opened by the pusher rod E, the countervalve M will close at the same time in
consequence of the pressure of the external air as the countervalve M will then be
sucked down or influenced by the partial vacuum formed in the passage K through
communication being made therewith by the depression of the valve G. The
operating bellows N on the underside of the air chest communicates therewith by
a suitable hole and will therefore also be exhausted of air, and consequently be
moved upwards by the pressure of the outer air. In this upward movement the
bellows N will through the intermediary of the bar O carry with it the pusher
rod P which will cause levers of the hammer mechanism to be operated. It should

page_text: be noticed that with the present improved device, the rise of the operating bellows
can be made of any length or extent, with a consequent correspondingly powerful
action of the hammer mechanism. Furthermore the operation of the mechanism is
only very slightly affected by the action of moisture in the air. The keys of the
pianoforte keyboard can also be operated with this arrangement.
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.) The combination of parts as hereinbefore described forming an improved
pneumatic action or relay for mechanically played keyboard musical instruments.
(2.) A pneumatic action or relay for mechanically played keyboard musical
instruments, consisting essentially of a countervalve M arranged on the air chest
above the respective operating chambers, the said valve M being connected with
the operating valve G situated in the chamber in such a manner that the counter-
valve M is kept open by the said valve G, whilst on the opening of the operating
valve G the pressure of the external air effects the closing of the countervalve M,
as and for the purpose set forth.
Dated thin 15th dow of October 1804
ROBERT E. PHILLIPS, M.I.M.E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Associate Agent.