Improvements in Compressed Air and Steam Engines.
Year: 1891

page_text: Date of Application, 27th Aug., 1891
Complete Specification Left, 19th May, 1892-Accepted, 25th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Compressed Air and Steam Engines.
I, JAMES, COURTHOPE PEACHE, Assoc. M. Inst. C.E. of Park Cottage,
Thames-Ditton, in the County of Surrey, Engineer do hereby declare the nature
of this invention to be as follows:-
My invention relates to improvements in compressed air and steam engines, and
its object is to provide for the absorption of the momentum of the reciprocating
parts of engines, such as pistons, valves and the like, and to cause the balance of
pressure always to be in the same direction along the line of movement of the said
parts.
In carrying my invention into effect I make use of a piston and cylinder herein-
after referred to as the "controlling" piston and controlling cylinder.
፡፡
The apparatus described below is described as applied to an engine in which the
cylinders are placed vertically over the crank shaft but is equally applicable to
engines in which the cylinders are differently placed.
1
The expression steam is to be also taken as including compressed air.
The controlling piston is rigidly connected to the part which it is intended to
control. It works in its cylinder and when it is at or near the beginning of its
stroke, steam under pressure is admitted by suitable gear, and cut off shortly after
the piston has commenced its stroke. The steam then expands during the remainder
of the stroke, and on the return stroke, it is compressed above the piston until, at
or near the end of the return stroke communication is again opened to the steam
supply. It is the pressure above the returning piston that is the operative agent
of this invention, and provision for its adjustment to the requirement of the case is
made by varying either the area of the piston, or the initial pressure of the steam,
or the capacity of the clearance space in the cylinder at the top of the stroke, or
within certain limits by the point at which the steam is admitted to, or cut off from
the cylinder, or by a combination of two or more of the above methods.
To absorb the momentum of the main reciprocating parts on the return stroke
in a single acting steam engine, the controlling apparatus or arrangement above
described, is used to assist the back pressure and compression obtained by the usual
distribution of steam in the working cylinders of the engine on the return stroke of
the pistous.
To regulate the admission of steam at the commencement of the stroke in tho
apparatus described above, I usually employ a piston-valve connected to the
controlling piston by a rod, and working in a valve cylinder that opens directly
into the controlling cylinder. In a suitable position in the side of the valve
cylinder, ports are formed, having a connection with the steam supply.
At the commencement of the stroke of the controlling piston, these ports are
uncovered by the piston-valve, and steam is admitted above the controlling piston.
As the controlling piston commences its stroke, it carries the piston-valve with it,
which latter covers the ports and thus cuts off the supply of steam to the controlling
cylinder. The steam expands in the controlling cylinder during the remainder of
the stroke of the piston, and is compressed on the return stroke of the controlling
piston until the piston-valve again uncovers the ports in the valve cylinder, when
the controlling cylinder is again placed in communication with the supply of
steam.
In a simple single acting engine I use the lower side of the controlling piston as
a working piston and place the upper side of the piston valve in direct communication
with the steam chest or source of steam supply.
In a tandem compound single acting engine, I place the high-pressure cylinder

page_text: immediately over the L. P. cylinder without any diaphragm or cover between
them, and use the upper side of the L. P. piston as a controlling piston, and the
H. P. piston as a piston-valve for regulating the admission of steam above the
L. P. or controlling piston.
In an engine arranged in accordance with the preceding paragraph, steam is
admitted above the H. P. piston by suitable valves and valve gear, and towards
the lower end of its stroke, the H. P. piston uncovers a row of holes round the
wall of the H. P. cylinder. These holes communicate with the receiver and allow
some of the steam to escape from the H. P. cylinder into the receiver. A further
portion of the steam contained in the H. P. cylinder at the end of its stroke is
exhausted into the receiver on the return stroke of the H. P. piston by valves in
the usual manner. The H. P. piston is made of a depth somewhat less than the
stroke of the engine, so that, at the top of its stroke, the row of holes referred to
above is uncovered by the lower edge of the H. P. piston, and thus steam is allowed
to pass from the receiver into the space between the H. P. and L. P. pistons. On
the next down stroke, the H. P. piston again covers these holes, thus cutting off
the supply of steam above the L. P. or controlling piston. Steam is admitted'
from the receiver to the under side of the L. P. piston and exhausted by means of
valves in the usual manner.
A quadruple expansion engine may be arranged in a similar manner. The H. P.
and second expansion cylinders are arranged tandem over one crauk, the third
expansion and L. P. cylinders being arranged tanden over another crank. In this
case the upper side of the second expansion and L. P. pistons, would be used as
controlling pistons, and the H. P. and third expansion pistons would act as valve-
pistons for them respectively.
Dated this 27th day of August 1891.
PHILLIPS & LEIGH,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Compressed Air and Steam Engines.
1, JAMES COURTHOPE PEACHE, Assoc. M. Inst. C.E., of Park Cottage,
Thames Ditton, in the County of Surrey, Engineer, 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 :--
My invention relates to improvements in engines driven by compressed air or
steam; and its object is to. effect the absorption of the momentum which the
reciprocating parts of the engine, viz. ;--the pistons, valves, their rods, and
connections, acquire during their motion away from the crank shaft. As a
consequence, a balance of pressure is always maintained in the direction of the
Baid shaft, and all knocking in the joints of the said parts, as well as in their
several junctions, prevented.
i
In carrying my invention into effect, I make use of a piston and cylinder herein-
after referred to as the "controlling" piston and "controlling" cylinder. This
combination is equally applicable to all types of engines, irrespective of the relative
positions of the cylinder and the crank shaft.
The expression "steam" wherever hereinafter used is to be taken as including
compressed air. The controlling piston is rigidly connected to the parts which it
is intended to control, and works with a reciprocating stroke in the controlling
cylinder. When it is at or near the beginning of its stroke, steam under pressure
is admitted by suitable gear, and cut off shortly after the piston has commenced' its
stroke. The steam then. expands during the remainder of the stroke, and on the
return stroke, it is compressed above the piston, until, at or near the end of the
return-stroke, communication is again opened to the steam supply. It is the pressure
above the returning piston that is the operative agent of this invention, and provision

page_text: for its adjustment to the requirements of the case is made by varying either the
area of the piston, or the initial pressure of the steam, or the capacity of the
clearance space in the cylinder at the top of the stroke, or, within certain limits, by
the point at which the steam is admitted to, or cut off from, the oylinder, or by a
combination of two or more of the above methods.
To absorb the momentum of the main reciprocating parts on the return stroke
in a single acting steam engine, the controlling apparatus or arrangement above
described is used to assist the back-pressure and compression obtained by the usual
distribution of steam in the working cylinders of the engine on the return stroke of
the pistons.
'To regulate the admission of steam at the commencement of the stroke in the
apparatus described above, I usually employ a piston-valve connected to the
controlling piston by a rod, and working in a valve-cylinder that opens directly into
the controlling cylinder. In a suitable position in the side of the valve-cylinder,
ports are formed, having a connection with the steam supply. At the commence-
ment of the stroke of the controlling piston, these ports are uncovered by the piston-
valve, and steam is admitted above the controlling piston. As the controlling piston
commences its stroke, it carries the piston-valve with it, which latter covers the
ports and thus cuts off the supply of steam to the controlling cylinder. The steam
expands in the controlling cylinder during the remainder of the stroke of the
piston, and is compressed on the return-stroke of the controlling piston until
the piston-valve again uncovers the ports in the valve cylinder, when the
controlling cylinder is again placed in communication with the supply of steam.
In a simple .e., single expansion single acting-engine, I use the lower side
of the controlling piston as a working piston, and place the upper side of the
piston-valve in direct communication with the steam chest or source of steam
supply.
In a tandem compound-i.e., double expansion single acting-engine, I place the
first expansion cylinder inmediately over the second expansion cylinder without
any diaphragm or cover between them, and use the upper side of the Becond
expansion piston as a controlling piston and the first expansion piston as piston-valve
for regulating the admission of steam above the second expansion or controlling
piston.
The
In an engine arranged in accordance with the preceding paragraph, steam is
admitted above the first expansion piston by suitable valves and valve gear, and
towards the lower end of its stroke, the first expansion piston uncovers a row of
holes round the wall of the first expansion cylinder. These holes communicate
with the receiver and allow some of the steam to escape from the first expansion
cylinder into the receiver, a further portion of the steam contained in the first
expansion cylinder at the end of its stroke being exhausted into the receiver on the
return-stroke of the first expansion piston, by valves in the usual manner.
first expansion piston is made of a depth somewhat less than the stroke of the engine,
80 that at the top of its stroke, the row of holes referred to above is uncovered by
the lower edge of the first expansion piston, and thus steam is allowed to pass from
the receiver into the space between the first expansion and second expansion pistons.
On the next down stroke, the first expansion piston again covers these holes, thus
cutting off the supply of steam above the second expansion or controlling piston.
Steam is admitted from the receiver to the underside of the second expansion piston
and exhausted by means of valves in the usual manner.
In the accompanying drawings, which are to be taken as part of this Specification
and read therewith,
Figure 1 is a sectional elevation illustrating my invention in its simplest form.
Figure 2 is a sectional elevation illustrating the application of my invention to a
double acting vertical engine.
Figure 3 is a sectional elevation of a single expansion single acting engine
constructed according to my invention.

page_text: Figure 4 18 & sectional elevation of a double expпusion single acting engine
constructed according to my invention.
Figure 5 is a sectional elevation of a modified form of double expansion single
acting engine constructed according to my invention.
Figure 6 is a longitudinal sectional elevation of a horizontal double expansion
single acting cugine constructed according to my invention.
Figure 7 is a longitudinal sectional elevation of a horizontal double expansion
single acting engine constructed according to my invention but with a variable
expansion valve gear.
In Figures 1, 2, 3, 4, & 5, the fly wheel, crank-shaft, eccentric and eccentric rod,
or their equivalents, with their connections, are omitted, but may be of any suitable,
or well known type.
•
Referring to Fig. 1, A' is the controlling cylinder; and b, the controlling piston.
c is part of the rod by which the controlling piston is rigidly connected to the
working piston, or other reciprocating-part of the cugine, which it is intended to
control is the steam supply. e is the valve-cylinder. It is an axial extension
of the controlling cylinder A with which it communicates. f is a piston-valve
working in the cylinder e. is the rod by which the valve is connected to the
controlling piston b. 13; B are steam ports in the valve cylinder. i is a closed
chamber constructed upon the annular cover al of the controlling cylinder, and
standing over the valve cylinder. The steam supply d opens into it.
The action of the controlling combination above described is as follows. The
controlling piston and its valve are represented as standing at the top of their
stroke. When the engine is started, steam flows into the space above the piston b
through ports B, B until the piston-valve f, as it travels downwards, passes over
these ports and cuts off the supply of steam. The steam enclosed above the
piston then expands in the controlling cylinder during the remainder of the down-
stroke, and is compressed again' on the return stroke until at, or near, the top of
the stroke, the piston-valve f again uncovers the ports B, B, and again places the
upper side of the piston & in communication with the source of steam supply. The
momentum of the reciprocating parts to be controlled, is absorbed by the pressure
of steam above the piston on the return stroke.
In Fig. 2, is shown my controlling apparatus applied to the reciprocating parts
of what would otherwise be a double acting engine. C is the working cylinder,
and A' is the controlling cylinder for the main reciprocating parts. The two
cylinders are shown as made in one piece. is a diaphragmn separating the two and
forming an end cover for each. The outer covers of the two cylinders are of the
usual construction.
is the working piston. is the controlling piston, and j is the rod by which
the two pistons are connected together. This rod works through a stuffing box l'
in the diaphragm 1. is the ordinary piston rod through which the controlling
and working pistons are connected to the crank shaft.
m is the piston-valve of the controlling cylinder; m³, its cylinder; and in³, the
steam port between them. In this case it will be seen that tlie valve for regulating
the admission of steam to the controlling cylinder is placed by the side of the latter,
and worked from the cross-head of the main piston rod by means of link k³,
lever which has its fulcrum in a fixed point, and a link taking on to the
valve rod &³.
The slide-valve n is shown of the hollow duplex piston valve type, but it should
be borne in mind that the present invention does not relate to the slide valve, and
consequently that may be of any suitable or convenient kind: ¹ is the cylinder
or steam chest in which the slide valve works. is the slide valve rod. o, o' are
the steam ports for the working cylinder. D is the main steam supply. d is a
branch to the chamber i, and is a branch leading from it to the valve cylinder m.
o² is the main exhaust. is the piston for controlling the momentum of the slide
valve and other reciprocating parts of the valve motion. It works in the upper

page_text: part of the slide valve cylinder n
Attached to, it is the valve n³ working in a
valve cylinder n. Ports n' for the admission of steam above the piston n³ are
formed in the side of the valve cylinder n°.
i is a closed chamber standing upon the top of the cylinder n', and over the
cylinder nº.
Dealing with the apparatus for absorbing the momentum of the valve motion,
the notion of the controlling piston and the valve-piston n³, &c., is the same
as that described in connection with Fig. 1; the correspondence of parts being as
|follows; n=c, n'=A, n³=b, nº=è, n³=ƒ, n²=B, and ii. Thus the tendency of
the eccentric rod and other reciprocating parts of the valve motion to be thrown
away from the crank shaft at the latter part of the upward stroke, by the momentum
acquired by them, is checked, and the knock which would otherwise occur in the
bearings and joints, is obviated by the balance of pressure being always maintained
in the direction of the crank shaft.
In the position illustrated the working piston is at the top of its stroke. Steam
is being admitted by valve m and port m above the controlling piston k'. As soon
as the downward stroke is commenced, steam' is cut off by the valve m actuated by
links, and lever . Steam then expands in the controlling cylinder A' and
is again compressed on the return stroke until the piston again arrives at the top
of its stroke and the port m' is again uncovered. The momentum of the working
piston and the other reciprocating parts attached to it, is controlled, and the force
which is developed by the pressure of the steam during the up-stroke of the said
piston, is overbalanced by the pressure of the steain in the controlling cylinder A
acting downwards upon the controlling piston kl. There is thus maintained a
thrust always in the direction of the crauk shaft.
It should be noticed that at the commencement of the return stroke, the actual
down pressure upon the controlling piston is probably less than the pressure under
the working piston. If, therefore, the parts were at rest or were working slowly,
there would be an upward pull upon the crank pin. When, however, the engine
is making a sufficient number of revolutions per minute, the inertia of the working
piston and other reciprocating parts attached to it, during the first half of the
return stroke, and while their speed in the direction of the axis of the working
cylinder is being increased, more than counterbalances this excess of upward
pressure on the working piston. I make use of these two opposing forces to reluce
the downward pressure on the crank pin, during the first half of the upstroke, to
the minimum consistent with preventing "knock," thus relieving, as far as is
practicable, the strain and wear on the crank pin and bearings.
in the second half of the return stroke, when the momentum' acquired by the
working piston and the other reciprocating parts attached to it, has to be over-
powered by the downward pressure of steam on the pistons, the pressure of steam
on the piston & is increasing, owing to the compression to which it is being subjected,
that under the working piston diminishes as soon as steam is cut off from the
working cylinder, and the pressure above the working piston increases as soon as
the exhaust port above it viz.,-o is closed. By properly proportioning the areas
of the working and controlling pistons j', ', as well as the distribution of steam to
them respectively, there can be obtained a balance of pressure in a downward
direction, i.e., towards the crank shaft, sufficient to overbalance the momentum of
the said working piston and other reciprocating parts attached to it.
In a single acting engine, there should always be sufficient pressure against the
bearings of the reciprocating parts on the upward stroke to keep them always
pressed in a downward direction, but not more pressure than is sufficient for the
purpose. The correct amount of pressure can be provided for by properly
proportioning the parts described.
The above remarks about single acting engines are applicable to the other forms
of engines described in this Specification, as well as to that shown in Fig. 2.
For the purpose of facilitating the starting of an engine such as that shown in

page_text: "
Fig. 2, a valve o is inserted in the supply branch to the controlling cylinder.
By closing this valve the supply of steam is cut off from the controlling cylinder,
and the engine will then start as an ordinary double acting engine, the partial
vacuum formed above the controlling piston being more than overcome by the
steam pressure above the working piston during the down stroke, and assisting
the pressure of the steam under the working piston on the up stroke. As soon as
the engine gets fairly under weigh, the valve o is opened and the controlling piston
and cylinder thrown into operation. -
In Fig. 3 is shown the application of my controlling apparatus to a single
expansion single acting engine. bis the controlling piston, and A' is the controlling
cylinder. The under side of the piston b, and the lower end of the cylinder A' are
used as the working piston and cylinder, respectively. c is the ordinary piston rod
through which the controlling and working piston is connected to the crank shaft.
is an extension of the piston rod to which the piston-valve fis connected: This
piston-valve works in a cylinder e that is placed axially over the main cylinder A!.
B, B are ports in the side of cylinder e for admitting steam above the controlling
piston. D is the main steam supply; and d, the branch supply to the closed
chamber i. m is the slide valve, shown as of the piston-valve type, and k' is the
valve rod. m³ is the valve cylinder; o, the steam port to the cylinder A¹; anḍ
o, the main exhaust.
The action of the steam above the controlling piston bis the same as that
described in connection with Fig. 1, and for that reason the same reference letters
are used.
b
Steam is admitted to the under, or working, side of piston 6 by valve m and
port o during the up stroke, and exhausted on the down stroke in the usual
manner.
Referring to Fig. 4, p is the first expansion piston working in cylinder pl. ris
the second expansion piston working in cylinder. These two pistons are connected
together by the trunk p*.
e is the usual piston rod. p is the steam port to the first expansion cylinder,
is the steam port to the second expansion cylinder, D is the main steam supply,
and o, the main exhaust.
The slide valve q¹ works in a cylinder or steam chest 9.
hollow treble piston-valve type. 9, q, q* are valve rings.
9, 9 and g', gl are holes for the passage of steam.
It is shown as of the
q' is the valve rod.
The upper side of the low pressure piston r acts as the controlling piston, and
the upper part of the cylinder as the controlling cylinder.
The first expansion piston pacts as a piston-valve for regulating the admission of
steam to the upper or controlling side of the piston r. is a port formed in the
side of the cylinder p'.
The action of the engine and controlling combination is as follows. In the
position shown steam is being admitted by valve q' and port.p to the upper side of
the first expansion piston p, and steam at the full pressure of that above this piston
passes by port to the annular space and upper side of piston r. Shortly after
the commencement of the down stroke, the piston passes over the end of portr³
thus cutting off the supply of steam above the piston r. Steam expands above this
piston for the remainder of the stroke, and is compressed again on the return stroke
in the manner already described in connection with other applications of my
controlling apparatus..
On the return or up stroke of the piston p, steam exhausts through port p³ and
holes
9, 9 into the interior of the hollow piston-valve q', and thence by holes g¹, g¹
and port into the second expansion, or low. pressure, cylinder. The exhaust.
from this cylinder on the down stroke is by port past the end of the valve o' to
the main exhaust o².
To facilitate the starting of an engine such as shown in Fig. 4, I place a valve r³,
as shown, near the top of the low pressure cylinder but sufficiently low down, BO

page_text: that the first expansion piston p shall cover the port before the low pressure
piston uncovers the aperture leading to the valve. This is to provide that
there shall not be a blow through of steam from the first expansion cylinder on
opening the valve. I also place a valve r" between the main steam supply D
and the lower or intermediate receiver part of valve cylinder y. In the position
shown, the two valves are closed, and the engine then works as a single acting
engine as already described. If, however, the valve is opened and the valve
turned so as to open a communication between the main steam supply D and the
intermediate receiver, 'the engine will work as a double acting engine; for there
will be no pressure in the space between the first and second expansion pistons
except just at the top of their stroke. The pressure in the high pressure steam
chest and in the intermediate receiver is the same because the valve 11 forms a
free communication between them. On the down stroke, the steam pressure acts
on the upper side of the first expansion piston p, forcing it down, (the under side of
the low pressure piston being then in communication with the exhaust o³), and on
the up stroke, the pressures per square inch on the under side of the low pressure
piston and on the upper side of the high pressure piston p being the same, (for
both are then in communication with the receiver and steam supply D), the total
pressure on the under side of the low pressure piston, owing to its greater area,
exceeds that on the upper side of the first expansion piston, and forces the pistons
up. The engine thus works as a double acting engine until the valves and
are closed.
Q is a steam jacket provided for preventing condensation of steam in the first
expansion, and controlling cylinders.
'
Referring to Fig. 5, this engine is similar to that shown in Fig. 4, but differs
from it in that steam for the controlling cylinder is taken from the intermediate
receiver instead of from the steam supply.
K K is the intermediate receiver. ', ' are ports which establish a communica-
tion between the said receiver and the controlling cylinder. The first expansion
piston p is made rather shorter than the stroke of the engine. It is attached to
the low pressure piston by an extension g of the main piston rod. At the lower
end of the stroke, the first expansion piston uncovers the ports s', st, and allows a
portion of the steam contained in the high pressure cylinder to escape into the
intermediate receiver. At the top of the stroke, the lower edge of the piston p
uncovers the ports s', s', and steam flows from the receiver into the space above the
controlling piston r.
The other parts of Fig. 5 and their working are identical with the corresponding
parts of Fig. 4, and are marked with the same reference letters respectively.
A triple expansion engine, according to my invention, may be made by combining
three pairs of cylinders of either construction illustrated in Figs. 4 or 5, with a
triple throw crank shaft. The high pressure cylinder of one of the pairs of
cylinders would act as the first expansion cylinder, steam at full pressure being
Bupplied to it. The two other high pressure cylinders of the other two pairs would
together provide for the second stage of expansion, and the three low pressure
oylinders of the three pairs would together provide for the third stage of expansion.
Suitable connecting pipes would have to be provided between the various cylinders,
and the arrangement of valves would have to be modified from that shown in Figs. 4
and 5.
A quadruple expansion engine, according to my invention, may be made by
combining a pair of cylinders of either construction illustrated in Figs. 4 or 5, and
a second pair of cylinders of larger size, with a two throw crank shaft. The
exhaust from the smaller pair of cylinders is connected to, and forms the supply
of, the larger pair of cylinders.
Referring to Fig. 6, the construction of the cylinders, pistons, and valves, and
consequently their operations, are identical with those illustrated in Fig. 4 and
described therewith. The several parts are therefore marked with the same
letters, respectively.

page_text: An advantage of the horizontal engine is that a more thorough drainage of the
condensed steam is practicable than in the case of a vertical engine.
The crosshead, connecting rod t', crank pin t, and the mechanism for working
the valve rod 7, are all contained in a closed chamber which contains a bath of
suitable lubricant, such as oil and water. 1ª and tº are glands in the said chamber
through which the piston rod c and the valve rod q, respectively, work. Their
function is to prevent the escape. of lubricant. The chamber t is effectually
separated from the steam cylinders and valve chest. Suitable glands are
provided on these to prevent the escape of steam, as well as, in the case of the
engine being connected to a condenser, to prevent the leakage of air past the piston
and valve rods.
The mechanism for working the valve rod q³ consists of a link u attached at one
end to a point on the connecting rod, and at the other end to one arm of a bell
crank lever which has its fulcrum at . The opposite arm of the bell crank
lever is connected to the valve rod go by means of the link u.
Referring to Fig. 7, the engine is similar to that illustrated in Fig. 6 and
described therewith, with the exception of the mechanisin for working the valve
rod. The several parts are therefore indicated by the same letters.
The mechanism for working the valve rod q' consists of a link v attached at one
end to a point on the connecting rod, and at the other end to a block v² sliding
in the guide. This latter is pivotted at a point at or near its centre (not shown)
and can be placed at any desired angle by means of the link and rod . This
rod is led through a gland in the chamber t, and may be controlled, by means
of a centrifugal, or other governor, direct, or through a relay, thus automatically
adjusting the angle of the guide ³, and consequently regulating the admission of
steam to suit the conditions under which the engine is working.
I wish to call attention to the fact that in the double expansion engines
illustrated in Figs. 4, 5, 6, and 7, the construction and arrangement of the slide
valve q provides for steam only at the pressure in the intermediate receiver being
behind the valve rings 9, 9, and qt, and that this, while sufficient to press them
out and keep them steam tight, does not subject them to so much wear as would
steam at the full pressure.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The application to steam or compressed air engines, of a piston and cylinder
for controlling the momentum of the reciprocating parts, substantially as described.
2. The combination with a reciprocating part of a steam or compressed air
engine, of a controlling piston, cylinder in which it works, piston-valve rigidly
connected to the said piston, cylinder in which the said valve works and ports
through which steam or compressed air flows. into the controlling cylinder, as set
forth.
3. The combination of working piston rigidly connected to a controlling piston
and each working in a separate cylinder, valve and ports for regulating the
distribution of steam, or compressed air to the cylinder of the controlling piston,
valve for shutting off the supply of steam or compressed air to the said distribution
regulating valve, and port through which steam or compressed air flows into the
controlling cylinder, as set forth.
4. The combination of first expansion piston rigidly connected to a combined
.controlling and low pressure piston, each working in a separate cylinder, ports for
regulating the distribution of steam or compressed air to the cylinder of the
controlling piston, port and valve from the controlling cylinder through which the
steam or compressed air distributed to the said cylinder blows off when the said
valve is open, port and valve from the main supply delivering steam or com-
pressed air therefrom to the intermediate receiver when said valve is open, as
set forth.

page_text: 5. The improvements in engines as described, and shown in my drawings attached.
Dated this 19th day of May 1892.
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.