Improvements in Electro-pneumatic and Pneumatic Movements for Organs.
Year: 1895

page_text: Date of Application, 18th Mar., 1895
Complete Specification Left, 13th Dec., 1895-Accepted, 15th Feb., 1896
PROVISIONAL SPECIFICATION.
Improvements in Electro-pneumatic and Pneumatic Movements
for Organs.
I VINCENT WILLIS of Rochester Terrace, Camden Town in the County of
Middlesex, Organ Builder, do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to provide for the different requirements of the
organ, extremely sensitive pneumatic apparatus which is especially adapted for use
where the impulse is initiated by electro-magnets, and to secure permanency of
adjustment in the electrically operated valves.
To accomplish these objects, I adopt an arrangement by which the greater part
of the power required to open the supply valve is provided as a supplement to a
considerably reduced impulse which suffices to secure the action of the motor
pneumatic lever.
In the bottom of a wind chest I arrange, as a valve seat, two concentric cylinders
of equal length, and connected by a base of some thickness. These cylinders
divide the space embraced by the valve seat into two approximately equal areas.
From the bottom of the chamber formed by the inner cylinder extends a channel
which passes horizontally right and left through the base of the valve seat.
Connected with one end of this channel is an adjustable tube forming a seat for an
electrically-controlled minute supply valve. The other end of this channel passes
on through the extended bottom of the wind chest, and turns up into free air, to
receive a minute exhaust valve to be presently described. The outer annular
chamber of the double valve seat is connected by a series of holes through the base
with a groove which leads to the motor pneumatic lever and its exhaust valve
scat. The double valve seat is fitted with a disc valve which has a stem leading
upwards to a pneumatic spring capable of relieving the valve of, say, its resistance.
Beyond the pneumatic spring is a cavity from which a channel is carried into the
groove leading to the motor pneumatic lever, in order that the complete inflation
of the motor pneumatic lever may render the pneumatic spring inert, and cause the
supply valve to fall down to its seat. It is important that the travel of this
partially balanced, automatically closing supply valve shall be limited to the
required amount, and that the rush of air into the pneumatic lever should partially
exhaust the pueumatic spring.
The electrically controlled minute supply valve is arranged and constructed in a
novel manner, when instantaneity of action is the all the important consideration.
Through the centre of the top and bottom of a rectangular iron frame, which may
te laminated, I arrange cores which nearly meet in the centre; the lower being
tubular, is a continuation of the channel in connection with the central cavity of
the double valve-seat, and is in the wind chest. The upper end of the tubular core
is fitted with a non-metallic valve seat, on which rests a very light iron disc valve,
slightly dished, not larger than the tubular core, having a short stem, which is
guided in the centre of the tubular core. The valve is suitably covered to secure
perfect soundness. The upper core, which should be rather smaller than the
tubular core, and should have its end shaped somewhat to fit the dished valve, and
be fitted with a minute buffer spring and covered, to prevent metallic contact, must
be adjusted to give the valve the very minute travel required. Surrounding the

page_text: cores is the magnetising coil of insulated wire. The smaller upper core, and a
preparation of the bobbin, provide space for the air to pass down to the valve.
It will now be understood that the valve is in the centre of the magnetising coil,
and in an intense magnetic field, and by the operation of a well-principle will, when
the circuit is made, be ejected by the tubular core, and powerfully attracted by the
upper core.
It is also favorably magnetised.
The distance between the polès of this elèctromagnet once adjusted, will remain
invariable.
When economy of current is the important consideration, I prefer a tri-polar
laminated magnet, with a slightly shortened centre pole, in order to provide the
necessary travel for a very thin flexible armature which covers the three poles.
Under the centre pole a minute valve seat is arranged, and the armature, suitably
covered above and below, rests lightly on the seat, and forms the valve. In this
case the electro-magnet would be fixed by its outer poles to the same surface as
the valve seat, and therefore the adjustment would be invariable.
The electrically-controlled exhaust valves, which must be capable of overpowering
the supply valves, suitably guided, simply rest on valve seats, and are of very 'thin
iron. These valve seats are conveniently provided by a tripolar electro-magnet
fitted with tubular outside cores and non-metallic valve seats, one core being of
small diameter, and connected with the channel that leads from the central
cavity of the double valve seat, the other of greater diameter, and in connection
with the groove leading to the motor pneumatic lever. One thin, coated, armature
valve may cover the three poles, and one magnetising coil will divide its energy
approximately in the required proportion. There is no difficulty in sealing vents
normally closed, and almost any arrangement will suffice.
The action of the apparatus is as follows:-The electromagnets being energised
by the depression of a key of the manual, the minute supply valve is opened, and
the independent exhaust valves are simultaneously empowered to resist the air
pressure. As soon as compression is complete in the central chamber of the double
valve seat, the pneumatic spring already pulling at the seated supply valve over-
comes the diminished resistance, and fully opens it, admitting air to the annular
chamber, and, through it, to the groove and motor pneumatic lever, which it inflates.
But compressed air is now behind the pneumatic spring, rendering it inert, and
closing the supply valve. On the cessation of the current energising the electro-
magnets, the attractive power ceases, and the exhaust valves are opened by the
pressure of the air, due to the wad on the motor pneumatic lever, overpowering
and sealing the supply valves. On the complete deflation of the motor pneumatic
lever, the exhaust valves return to their normal resting position.
To adapt this principle to pneumatic organs, I arrange under and outside the
wind chest, and immediately under the double valve seat of the supply valve, a
similarly constructed double valve seat, inverted, but having an annular chamber
of twice the area, and I connect the central cavities of the two valve seats. The
annular chamber forms an exhaust vent for the motor pneumatic lever. This double
valve seat is fitted with an exhaust valve formned on a diaphragm pneumatic lever.
The exhaust valve has a small central hole covered by a flap valve, which is
entirely within the central cavity of the double seat. This valve and diaphragm
pneumatic lever are held up to the external double seat by a light adjustable
spring.
On an impulse being transmitted to the underside of the diaphragm pneumatic
lever, it presses the exhaust valve home, lifts the flap valve, and charges the
central cavity of the valve seat, enabling the pneumatic spring to open the supply
valve, as before, and inflate the motor pneumatic lever, when the supply valve
falls, as already explained. On compression being released, expansion, followed
by momentum, sucks down the diaphragm pneumatic lever, opening the exhaust
valve, and permitting deflation of the motor pneumatic lever. The spring
returns the diaphragm pneumatic lever to its normal position, ready for the next
impulse.

page_text: In this apparatus, the seating of the supply valve, it will be understood, iş
consequent on the opening of the exhaust valve.
This form of apparatus may be electrically operated by some such arrangement
as that shewn in the Specification of Patent 15182 of 1889, and used for the less
important requirements of the organ.
It may also be used in a very novel manner, for if the supply valve is made
more sensitive, the mere concussion of a quickly closed exhaust valve is sufficient
to initiate the action of the apparatus.
Indeed, this may prove to be the most economical method of applying electrical
energy, where quick action is not desired. because the extended armature of the
arrangement above referred to may be supported by a spring, and so leave the
electro magnet nothing but inertia to overcome, till the exhaust valve is seated,
and the armature is in a powerful position.
This apparatus can be adapted to compressed or attenuated air, or the inverted
condition technically known as the "let out system, which is practically ap
attenuated arrangement.
"
The minute supply valve may be coupled to a minutę exhaust valve, as
heretofore.
A more complete use of tubular cores adapts the electromagnets described to,
"let out"
systems.
In order to increase the efficiency of the pneumatic lever, I attach the flexible.
part thereof in a novel manner to the boards, avoiding the creasing of the leather,
which in the closed position of the pneumatic lever contracts the surface area,.
thereby reducing the efficiency of the lever.
To the edges of the fixed board, I attach one edge of the leather in a reverse
position to that usually adopted. I then lap over the leather to reach the movable
board, and secure that edge thereto in the usual manner.
The motor pneumatic lever may be arranged to control the condition of the
cavity behind the pneumatic spring, bringing it into connection with free air,
when at rest, and charging it with compressed air when in a partly inflated
condition.
A very light double beat valve could be arranged in such a manner as to perform
the automatic actions of the supply valve described.
The pneumatic spring might be fitted with non-return flap valve, and the stem
coupling it with the supply valve made slightly elastic, as au alternative to the
suction principle above referred to.
Dated this 18th day of March 1895.
NEWTON & SON,
Agents for the Applicant.
VUMI LELE SPECIFICATION.
Improvements in Electro-pneumatic and Pneumatic Movements
for Organs.
I VINCENT WILLIS of Rochester Terrace, Camden Town, in the County of
Middlesex. Organ Builder, 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 main object of this invention is to provide, for the different requirements of
the organ, extremely sensitive pneumatic apparatus, which is especially adapted.
for use where the impulse is initiated by electro-magnets, and to secure permanency
of adjustinent in electrically-operated valves.
To this end, when the initial valve is actuated by electricity, I provide a special
construction of such valve, which will produce the desired impulse with the use of

page_text: a minimum amount of motive power, and admit sufficient air to the underside of
the lightly-seated supply valve, to lift it from its seat, and thereby open a way for
the passage of air from the wind chest to the motor pneumatic lever. I also
ensure the certain and rapid action of the exhaust valve, a point essential to the
production of a rapid iteration of sound.
In the accompanying drawings, I have shown several arrangements of parts for
effecting the inflation and rapid exhaustion of pneumatic levers or motors, by the
instant action of a small initial valve, opened by the depression of a key or pedal.
Fig. 1 is a sectional elevation, illustrating the construction and operation of the
parts situate between the initial valve and the pneumatic fever or motor, and
including both the initial valve and motor.
In this figure, A is the motor, and B the electrically-worked initial valve,-the
parts in connection therewith being so constructed and fitted, that when the valve
is lifted from its seat, air from the wind chest will pass it, and find its way through
a passage C, to a double-lipped double valve seat D, set in the bottom of the wind
chest E.
The upper end of this double valve seat is closed by a valve F, which is the
supply valve, and the lower end of this double valve seat, which projects beyond
the bottom of the wind chest E, is closed by the valve G, which is the exhaust
valve.
It is to the centre of this valve seat D, extending from end to end thereof, that
the air which passes the initial valve is admitted for the purpose of releasing the
supply valve from its seat, and thereby bringing the motor lever A into com-
munication with the wind chest E.
It will now be convenient to describe in detail the construction and action of the
initial valve B, which, on the depression of a key or pedal, initiates the movement
for charging the pneumatic lever or motor A with air.
Fixed to the bottom of the wind chest E, is an electro-magnet, consisting of a
frame of soft iron, fitted with a divided core, which forms the pole pieces b¹ b².
The pole piece is solid, pendent from the frame, and is adjustable. The pole
piece is tubular, and carries a valve seat 3, of wood or other non-magnetic
material, into which is fitted a conical valve 6 of soft iron.
Surrounding the pole pieces 2, is a bobbin 6, wound with insulated wire.
This bobbin fits closely onto the tubular pole piece 62, but space is left between
it and the pole piece, which is the positive pole, for the passage of air from the
wind chest through the hollow pole piece 2 (which is the negative pole).
When an electric current is passed through the bobbin coils, by the depression
of an organ key or pedal, the electro-magnet is energized.
The conical valve is situate immediately below the pole piece b', which is cone-
tipped, to enter a central depression in the valve, and is covered to prevent actual
metallic contact therewith.
Supposing the pole 62 to be properly adjusted, the limit of motion of the valve, when
the electro-magnet is energized, will be limited to the extent only necessary for freeing
the valve from its seat, and the electrical energy required for this movement will
be minimised, the positive and negative poles simultaneously serving to lift the
valve, the one by attraction, and the other by repulsion.
The air passing through the hollow pole piece 72, finds its way through the
channel C to the central cavity of the double valve seat D, which, at its upper end,
is flared, to expose a large surface of the supply valve to the air supplied by the
channel C.
The supply valve seat (see Fig. 1^) is divided into two areas, the annular being
by preference devoted to operative, and the other to controlling, purposes.
The annular area is continued by a series of holes through the bottom of the
wind chest, and is thus brought into communication with a channel H, which leads
directly to the pneumatic lever A.
The inner or central area extends from end to end of the double valve seat,
presenting, however, at its lower end a smaller diameter of opening to the escape

page_text: valve G than, at its upper end, to the supply valve F. The construction of both
ends of the valve seat is alike, but the annular area of the lower seat, which
receives the exhaust valve, is enlarged, to facilitate the passage of air through it
from the channel H, with which it is in communication. This channel, I have
said, is in direct communication with the motor lever A, which takes its inflation
from that channel, and maintains its inflation so long as the escape valve G remains
closed.
The channel H communicates with a double-acting disc pneumatic lever K,
fitted in the top of the wind chest, and serving to operate the supply valve F.
K is a trumpet mouthed pipe leading from the channel H to the pneumatic
lever K, for the purpose of deflating or ensuring its partial exhaustion, while the
pneumatic lever A is expanding, and inflating it immediately the motor lever A is
fully inflated.
To the centre of the diaphragm of the pneumatic lever K, the efficient area of
which is less than that of the valve F, the stem of that valve is connected, so
that, by the distension and contraction of the pneumatic lever, the valve is lifted
from and closed upon its seat.
This action of the pneumatic lever K (which, when the supply valve is closed,
has always a tendency to lift it) is caused by the varying pressure of the air
admitted to it, there being at one moment a rush of air past the mouth of the
pipe K', causing a slackness of the pneumatic lever, and a consequent retention
of the valve F in a raised position, and immediately succeeding this, a rapid return
of air to the disc lever, on the complete inflation of the motor lever A, thus
causing the depression of the supply valve to its seat.
The exhaust valve G is similarly connected to a pneumatic spring G¹, situate
immediately below the valve, and connected therewith by the valve stem g.
A pipe G leads from the space below the pneumatic spring G¹ to the channel H,
which connects with the motor lever A, and it is through this channel that air
is supplied thereto and withdrawn therefrom, for the purpose to be presently
explained.
The valve G is held lightly to its seat by a spring g', but for retaining it on its
seat against the pressure of the wind in the centre of the valve seat D, an electro
magnet I is provided.
The armature 1 of this magnet is fulcrummed at i, and connected at with the
valve stem g.
When the key is depressed, and an electric current is sent into the electro
magnet B, a current at the same time passes to, and energises the electro magnet I,.
the armature of which is attracted, and caused to hold the exhaust valve G firmly to
its seat, so long as the finger of the player is on the key.
Directly the key is released from pressure, the exhaust action above mentioned
with respect to the motor lever A will take place.
The air will, by reason of this exhaust, be sucked out of the pneumatic spring G¹,
and the valve G. released from the pressure of the armature, will, assisted by the
back pressure of the air in the valve seat, be drawn down, and retained open, until
the deflation of the motor lever A is complete. The spring g¹ being then free to
act, restores the valve to its seat.
By the use of the pneumatic spring G', the power required from the electro-
magnet I to hold the escape valve G firmly to its seat, is minimised, while at the
same time the break in the current, due to the rise of the key, will leave the
pneumatic spring powerless to resist the opening of the escape valve.
From the foregoing description it will be understood that the supply valve rises
immediately on the depression of the key, and reseats itself automatically so soon
as the motor pneumatic lever is inflated, and that the exhaust valve, acting
independently of the supply valve, is held to its seat until the key is released from
pressure, when the exhaust valve, no longer supported by its electro magnet, will
yield to the pressure of the air in the motor pneumatic lever, overcome the elastic
pressure of the light spring g', assisted by the drag put upon it by its own.

page_text: pneumatic spring G', and open a vent for the escape of the air from the motor
pneumatic lever, such drag of the pneumatic spring being due to the back rush of
the air past the mouth of the pipe G..
Fig. 2 shows, in sectional elevation, another arrangement of parts for carrying
out, according to my invention, the rapid inflation and deflation of the motor
pneumatic lever, there heing, in this case, but one electro-magnet employed for
operating the motor, in place of two.
The letters of reference used refer to corresponding parts in Fig. 1, and the
necessity for repeating many details of construction and action is thereby avoided.
In this case, the stem of the initial valve 64 is extended down the hollow core
(negative pole), and carries at its lower end a soft. irop escape. valve 64*, which,
when seated, closes the hollow core.
The base of the frame b of the electro-magnet B is provided with two air
channels cc, which are continued through the bottom of the wind chest E, the
one, c, communicating with the central cavity of the valve seat D by the pipe C,
to raise the supply valve F, and thereby pass air from the wind chest E, through
the channel H, to the motor pneumatic lever A, and the other, c*, communicating
with a chamber containing a small pneumatic lever G, the use of which I will now
proceed to explain.
To the centre of this pneumatic lever is connected a valve stem g², which passes
through a chamber.G immediately below the pneumatic spring G connected with
the escape valve G.
The opposite ends of the chamber G₁ form valve seats for two external
valves gg, carried by the valve stem. 92, which is connected to a spring go, that
tends to close the valve 93.
The short pipe G2 connects the air channel H with the pneumatic lever G³.
The action of this apparatus is as follows:--Air passing along the passage c* to
the pneumatic lever G³, causes that lever to seat the valve g³, thereby. completely
cutting off the communication between the chamber G and the channel H, the
seat of the escape valve g being at that time open to the atmosphere.
This opening of the chamber below the pneumatic spring G, enables the air in
the channel H to act with full force upon the pneumatic spring G', and thus hold
down firmly the external escape valve G, by reason of the greater area of the
pueumatic spring exposed to the pressure of the air in the channel H.
C
So soon, however, as the pressure on the key which has caused the energising of
the electro-magnet and the rise of the initial valve, has been removed, the pressure
of the air in the channels c c will be destroyed by the drop of the valves b, 10.
The air from the channel H will then force back the pneumatic lever G³, thereby
closing the exit opening from the chamber G, and opening it to receive compressed
air from the channel H.
The effect of this will be to inflate the pneumatic spring G, and leave the
valve G free to open under the pressure of the air below it.
An instant discharge, therefore, of the air from the motor pneumatic lever is
effected as in the first described arrangement, the supply valve F having been
seated immediately on the inflation of the pneumatic lever A, as above explained.
I may here point out that the pneumatic spring of the supply valve F might be
controlled by a similar arrangement. to that just described, for controlling the
escape valve, and that the motor pneumatic lever might operate it; also that the
arrangement shown for controlling the supply valve is applicable to the escape
system. In other words, the systems are interchangeable, but the arrangement
shown at Fig. 2 is preferred.
When economy of current is the important consideration in operating the initial
valve, I prefer to use a tripolar laminated magnet with a slightly shortened centre
pole, in order to provide the necessary travel for a very thin flexible armature
which covers the three poles.
This form of magnet is illustrated at Fig. 24, which represents it in sectional
elevation.

page_text: The poles are formed of laminated soft iron, the central or positive pale being
made up from all the laminations, whereas the two negative poles are composed
each of half the number of laminations. 1 is the positive pole and 2, 2 the negative
poles, to which latter the elastic armature 3 is made fast, and carries the initial
valve 6, the whole being contained, together with the magnetic coil, in the wind
chest.
Under the centre pole, a minute valve seat is arranged, to receive the valve b*,
and the armature is clothed to prevent contact with the pole. Pendent from the
lastic armature is a rod 4, which carries the escape valve 6₁*. This valve acts like
the valve Fig. 2, closing the vent for the initial air supplied by the
passages c, c, to the valve seat D, and to the pneumatic lever G³ of Fig. 2.
:
In this case, the electro-maguet is fixed, as shown, by its outer poles, to
the same surface as the valve seat, and therefore the adjustment would be
invariable.
I will now describe the modification necessary in applying my invention to
pneumatic organs which contain no electro-magnetic apparatus.
Fig. 2 shows a modification of the arrangement illustrated at Fig. 2, whereby
the initial action is obtained without the use of an electro-magnet.
On the depression of a key, air is supplied from a wind chest through well-known
pneumatic apparatus, directly to the pipe C, which divides, as in the arrangement
Fig. 2, the initial stream of air,-one portion entering the valve seat D, to lift the
supply valve, and the other passing to the pneumatic lever G³, which serves to
close the chamber below the pueumatic spring G1 to the channel H, and open
to the atmosphere, thereby enabling the spring G' to hold the escape valve G
firmly to its seat, as already explained.
Fig. 3 is a sectional elevation of a pneumatic arrangement in which the air
supply mechanism is similar to that shown in Figs. 1 and 2, similar letters in this
case being used to indicate like parts in those figures.
The initial wind supply enters by the channel C, as before, and is divided, one
portion going to the central area of the valve seat D to lift the supply valve F in
the wind chest E, and the other portion to the back of the pneumatic spring G', in
connection with the escape valve G.
The annular space in the valve seat D supplies air to the channel H for the
inflation of the pneumatic motor lever A.
The action is as follows:-The impulse transmitted by the performer simul-
taneously lifts the supply valve F and puts pressure on the underside of the
pneumatic spring G' of the escape valve G, which spring is, however, immediately
balanced by the action of air admitted by the supply valve to the channel H, when
the pressure on the back of the escape valve closes it firmly. The motor pneumatic
lever is now fully inflated; on the key being released, the air pressure ceases in
the central cavity of the valve seat D and below the pneumatic spring G', which,
immediately becoming active, opens the escape valve for the exhaustion of the
pneumatic lever; air now rushing from the motor lever, passes the bell mouthed
suction tube K', and pressing on the back of the pneumatic spring K, aided by the
air pressure in the wind chest, firmly seats the supply valve.
Another mode of introducing the initial air into the double-lipped valve seat D,
for the purpose of lifting the supply valve from its seat, is shown in sectional
elevation and plan view at Figs. 4, where G' is the pneumatic spring carrying a
rigid plate, upon which the valve G is mounted. The back of the pneumatic
spring is in communication with the channel C, through which the initial stream
of air passes, and a central hole, made through the spring and the plate which it
carries, serves to admit the air to the centre of the double valve seat D.
The valve G, composed of flexible material, is made fast to the plate, except at
its centre, where, taking the form of a bar, it covers the central hole in the
pneumatic spring, side openings being cut in the valve, to allow of the passage
through it of the air, when the central bar of the valve yields to the pressure of
the air admitted below the pneumatic spring.

page_text: The valve G is held to its seat by a light spring g', as shown, and while so
situate, it is free to pass air upwards, to act upon, and open the supply valve F.
When the deflation of the motor pneumatic lever is to take place, the pressure
below the spring G¹ ceases, and. the valve G is forced from its seat, to discharge
the air from the motor pneumatic lever.
Pneumatic actions constructed under the principles described, suitably propor-
tioned, and fitted with an elastic adjustable check, such as that shown in Figs. 4,
instead of the positive stop provided for the supply valve in the drawings, are
capable of reproducing, greatly reinforced, the kind of impulse transmitted to
them; in other words, are capable of actuating the valves of the organ
precisely as the finger of the organist actuates the valves of the transmitting
apparatus.
Thus, a slow depression of the key produces a gradual rise of compression under
the supply valve, thereby releasing it, and leaving it under the control of the
pneumatic spring, which, exerting a force determined by the initial impulse past
the mouth of the suction tube, retains the acquired lift, thereby inflating the motor
pneumatic lever at a speed corresponding to that of the transmitting apparatus or
key. Again, if the key is suddenly depressed, compression is sudden, and is
increased by the momentum of the column of air conveying the impulse. The
supply valve consequently responds vigorously, thereby causing the suction
tube K to act energetically, retaining, and even increasing, the lift of the supply
valve, thereby inflating the motor pneumatic lever with great rapidity.
The important feature in securing these results, is the detached independent
action of the supply valve. whereby its lift is not absolutely decided by the
duration of the energy applied. It will be observed that, once released, it is
within certain limits a free agent, and passes varying pressures of air, which
correspond with the momentum of the initiating impulse. As a consequence, a
supply valve suitably proportioned to its pneumatic lever, may be released by a
pressure below that which it controls.
From the preceding remarks it will be understood that, in transmitting the
impulse without variation to the motor pneumatic lever, great care will be necessary
in proportioning the pneumatic springs and levers to their respective supply and
escape valves. The drawings, therefore, must be considered as indicative only of
the construction of the parts, the weight of which, and the pressure of the wind
employed, may necessitate variations in the relative diameters of the valves and
elastic diaphragms.
Another part of my invention relates to the construction of motor pneumatic
levers.
In order to increase the efficiency of the pneumatic lever, I attach the flexible
part thereof in a novel manner, to the boards, avoiding the creasing of the leather,
which, in the closed position of the pneumatic lever, contracts the surface area,
thereby reducing the efficiency of the lever.
This is illustrated in two forms at Figs. 5 and 6,-Figs. 5 showing in plan view
and sectional elevation, a hinged pneumatic lever, and Fig. 6, in sectional elevation,
a disc pneumatic lever.
To the fixed board or bottom L, I attach one edge of the leather L', in a reverse
position to that usually adopted. I then lap over the leather to reach the board or
disc L, and secure that edge thereto in the usual manner.
2
In this way, the creasing of the leather is avoided, and its durability is thereby
secured.
From the foregoing explanation of the varied and delicate results aimed at, it
will now be evident why the old form of motor pneumatic lever, which, by reason
of its ribbed construction, is least powerful when collapsed, and therefore requires
a very high initial pressure, is unfitted for the duties now required from it. My
improved motor lever illustrated at Figs. 5 and 6, by reason of its construction,
responds at an carlier stage of inflation, and is thus suited to transmit the variable
touch of the player to the valves commanding the organ pipes.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. The means above described for imparting to a partially balanced supply valve,
the impulse initiated by the key or pedal.
2. The means described with reference to Fig. 1, for releasing the exhaust valve,
and thereby enabling the compressed air in the motor pneumatic lever to force open
that valve, and escape on the withdrawal of pressure from the key or pedal.
3. In combination with the supply and exhaust valves, the double valve seat D,
fitted to the wind chest, as described, and in communication with the channel that
supplies air to the motor pneumatic lever, for the purpose of delivering air thereto,
and conducting it therefrom.
4. The means above described for enabling the compressed air in the motor
pneumatic lever to open the exhaust valve on the withdrawal of pressure from the
key or pedal, as illustrated in Fig. 3.
5. The means above described for retaining the supply valve open until the
motor pneumatic lever has received its plenum of air, and seating the supply valve
immediately the motor pneumatic lever is fully inflated.
6. The means described for holding the exhaust valve to its seat, while the
pressure of the player is on the key or pedal, as illustrated by Figs. 2, 28.
7. The construction of combined non-return and escape valves, as described with
reference to Figs. 4 of the drawings.
8. The construction and arrangement of electrically controlled initial valves, as
described with reference to Figs. 1 and 2 of the drawings, whereby the valve is
centred in an intense magnetic field, and simultaneously attracted and repulsed by
the opposite poles of the magnet, thus facilitating its efficient action in a contracted
sphere, for the purpose above set forth.
9. The construction of tripolar magnet as explained with reference to Fig. 2ª, for
the purpose above set forth.
10. The mode of constructing pneumatic levers as described with reference to
Figs. 5 and 6 of the drawings.
Dated this 11th day of December 1895.
NEWTON & SON,
Agents for the Applicant.