Improvements in the Pneumatic Action of Organs.
Year: 1889

page_text: Date of Application, 21st May, 1889-Accepted, 22nd June, 1889
COMPLETE
SPECIFICATION.
Improvements in the Pneumatic Action of Organs.
I, THOMAS CASSON of Denbigh in the County of Denbigh, Bank Manager, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
My invention relates to organs which have their pipe valves opened by pneumatic
levers or their equivalents whenever, by the depression of keys or pedals, puffs or
currents of air under pressure are transmitted to the pneumatic levers or their
equivalents. The object of my invention is to render the action of the keys or pedals
easy and certain, and to facilitate the coupling of the several sets of the organ stops
as I shall describe referring to Fig. 1 of the accompanying drawings which represents
in vertical section the console or key desk of an organ having two key boards and a
set of pedals, with valves and passages according to my invention. S is one of the
keys for the swell organ, G is one of the keys for the great organ, and P is one of
the pedals. The keys S and G are connected by trackers to levers L, on which as
well as on the lever of the pedal P, are pivotted hoppers K pressed by springs M so
that studs near the ends of the hoppers are kept engaged in notches N in the backs
of their respective slide valves. The notch N is in each case made with a pro-
tuberance in its middle so that after the hopper stud has, by acting against the
protuberance, moved the slide valve against its upper or lower stop O, it can spring
over the protuberance so as to be ready, by acting against the protuberance in the
opposite direction, to effect the back stroke of the slide valve.
The slide valves present on their faces several parallel ports, and on the smooth
facing on which they work there are corresponding ports so that a very small
movement of the valve gives sufficient passage for air by opening several ports
simultaneously.
The three slide valves differ however in respect of their cavities and the ports which
they govern as follows:-The slide valve worked by the swell organ key S has a
single cavity S¹; it governs two ports from a duct S2, which is charged with air under
pressure, two ports to a passage S, and there is a port always open to a passage and
pipe S leading past a countercheck valve S G to the pneumatic lever or its
equivalent that is to be worked by the depression of the key S. The slide valve
worked by the key G has two cavities, the upper cavity S G₁ having ports governing
adınission of air under pressure from a duct S G2 to a passage S G³, and the lower
cavity G' having ports governing admission of air under pressure from a duct G² to
a passage G, and there is a port always open to a passage and pipe G³ leading to
the pneumatic lever or equivalent that is to be worked by the depression of the
key G.
The slide valve worked by the pedal P has three cavities P¹, G P¹ and S P₁,
having ports governing admission of air under pressure from three ducts P², G P2,
and SP respectively. It has also passages through it which when the valve is up,
as shewn, correspond with the passages P³, G P³, and S P³ respectively.
As all the valves are shewn in what may be termed their inert positions, the two
key valves down and the pedal valve up, the pipes S³, G³, P³, which lead from the
respective pneumatic levers or their equivalents are open for discharge S³ past S G*
out by S G³ or by S* and S P³; G³ through G₁ and G to G P3; and P³ directly
out. If by depressing S its slide valve is raised, air from S2 will pass S G₁ to S³.
If by depressing G its slide valve is raised air will pass from G2 to G³, also if S G²
be charged, air will pass by S G' and S G³ to the pipe S³ thus causing the swell
notes as well as the great organ notes to sound. Thus the charging of S G' effects
the coupling of the swell to the great organ.

page_text: When by depressing the pedal P its slide valve is lowered, if P2 alone is charged
the pipe P3 is supplied; if S P2 is charged, then air passes by S P³ to S₁ and S
working the swell organ notes, and if GP2 is charged air passes by G P³ and G*
to G3 working the great organ notes. Thus the charging of S P2 and G P³ couples
the swell and the great organ to the pedals. The charging or discharging of the
coupling ducts S G², S P2, and G P is effected by valves in any convenient
position worked by stop pulls or otherwise.
Instead of working the slide valves by studs projecting from the hoppers as above
described, they may be worked by the friction of blocks jointed to the hoppers as
shewn in elevation by Fig. 2 and in plan by Fig. 3. The hopper K has jointed to
it a block Q bearing on a guide piece R projecting from the back of the slide valve
with a stop at each end. When such a friction block is employed, the hopper may
be dispensed with by arranging the block to be pressed by an adjustable spring Ů
as shewn in Fig. 4.
Having now particularly described and ascertained the nature of this in-
vention and in what manner the same is to be performed I declare that what I
claim is:-
1. In a pneumatic organ, in combination with slide valves worked by keys and
pedals, coupling ducts which when they are charged with air under pressure, serve
by the movement of one key or pedal to supply the ducts governed by the
corresponding keys of other manuals substantially as described.
2. For working a slide valve, such as is referred to in the preceding claim, the
combination of lever, spring hopper pivotted thereon, and hopper stud engaging
in a notch of the slide valve having a protuberance in the middle, substantially as
and for the purposes set forth.
3. In a slide valve such as is above referred to subdividing the ports into several
narrow ports so that a small movement of the valve gives considerable area for
passage of air, substantially as described.
Dated this 20th day of May 1889
ABEL & IMRAY,
Agents for the Applicant.