Improvements in Compound, Triple Expansion, and Quadruple Expansion Engines.
Year: 1891

page_text: Date of Application, 2nd Sept., 1891
Complete Specification Left. 2nd July, 1892-Accepted, 6th Aug., 1892
PROVIDIUNAL DI ECIFICATION.
Improvements in Compound, Triple Expansion, and Quadruple
Expansion Engines.
We JAMES MARSHALL, and REGINALD WIGRAM, both of The Steam Plough
Works, Leeds, in the County of York, Engineers, do hereby declare the nature of
this invention to be as follows:--
In the Specification to Patent No. 9300 of 4890), we described a construction
of cylindrical tubular slide valve with packed piston parts and internal expansion
valves for governing a pair of parallel cylinders of a compound or twin engine.
Our present invention consists in the adaptation of a cylindrical tubular slide
valve or valves with an internal expansion valve or valves constructed and operating
substantially the same as described in the said Specification, to the regulation of
the flow of steam into and out of a single or twin compound engine with tandem
cylinders, or of a single or twin triple expansion engine with tandem cylinders,
or of a quadruple expansion engine with tandem cylinders, either single or double
acting.
For this purpose, in adapting the said slide valve or valves to a single compound
engine with tandem cylinders, we construct the cylindrical casing of the said valve
or valves with grooves and ports communicating with each end of the high and low
pressure cylinders, and with a groove and port leading to the exhaust, while the
cylinder slide valve has grooves and ports so formed and arranged as in one
position to cause high pressure steam to be admitted through its expansion valve to
the one end of the high pressure cylinder while at the same time it causes the steam
to pass from the other end of the high pressure cylinder to the opposite end of the
low pressure cylinder, and puts the other end of the latter in communication with
the exhaust; in another position of the valve, high pressure steam is admitted to
the other end of the high pressure cylinder, the previously admitted steam in the
first named end being made to pass into the opposite end of the low pressure
cylinder. In applying the valve to twin compound engines of the above kind the
cylinders may be either single acting or double acting, the cranks being place:1
at 180°; in this case the valve and casing ports and passages are so arranged that
the steam from the high pressure cylinder of the one engine is made to pass to the
low pressure cylinder of the other engine. In arranging such tandem engines to
act as triple expansion engines either single, or twin, the high pressure cylinder is
made single acting, the piston of the high pressure cylinder being made as a trunk
piston formed in one with the piston of the low pressure cylinder, and the ports and
passages of the cylinders, valve casing and cylinder valve are so arranged that, in
the case of twin engines, the steam from the one high pressure cylinder is made to
expand first into the annular space at one end of the low pressure cylinder of the
second engine, and thence into the other end of the same cylinder, from which it
then escapes to the atmosphere or a condenser. In the case of a single triple
acting engine of this kind, there is provided a steam chamber for receiving the
steam on its way from the high pressure cylinder to the annular space of the low
pressure cylinder.
In applying the said cylinder valve to a quadruple expansion engine, a similar
construction of engine to the above described twin triple expansion engine can be
employed, that is to say, two pairs of cylinders, each pair consisting of a large and
a small cylinder joined together, with a trunk piston for the small cylinder formed
in one with the piston for the large cylinder. In this case the ports and the
pussages of the cylinders, valve casing and cylinder slide valve are so arranged that
the high pressure steam, after acting in the one small cylinder is made to pass over

page_text: to the other small cylinder, which is of greater capacity, thence to the first large
cylinder and thence to the second large cylinder, which is of greater capacity. The
quadruple expansion engine may also be made with separate single or double
acting cylinders in which case the large and small cylinders would have inde-
pendent ordinary pistons and when double acting, the ports and passages of the
valve casing and cylinder slide valve might be duplicated.
It will be evident that the above described details of the several arrangements
may be variously modified.
Dated this 2nd dox of Santamber 1901
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Compound, Triple Expansion, and Quadruple
Expansion Engines.
We, JAMES MARSHALL, and REGINALD WIGRAM, both of The Steam Plough
Works, Leeds, in the County of York, Engineers, 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:-
In the Specification to Patent No. 9300 of 1890, we described a construction of
cylindrical tubular slide valve with packed piston parts and internal expansion
valve for governing a pair of parallel cylinders of a compound or twin engine.
Our present invention consists in the adaptation of a cylindrical tubular slide
valve or valves with an internal expansion valve or valves constructed and operating
substantially the same as described in the said Specification, to the regulation of
the flow of steam into and out of a single or twin compound engine with tandem
cylinders, or of a single or twin triple expansion engine with tandem cylinders,
or of a quadruple expansion engine with tandem cylinders, single or double
acting.
For this purpose, in adapting the said slide valve or valves to a single compound
engine with tandem cylinders, we construct the cylindrical casing of the said valves
or valves with grooves and ports communicating with each end of the high and
low pressure cylinders and with a groove and port leading to the exhaust, while
the cylinder slide valve has grooves and ports so formed and arranged as in one
position to cause high pressure steam to be admitted through its expansion valve
to the one end of the high pressure cylinder while at the same time it causes the
steam to pass from the other end of the high pressure cylinder to the opposite end
of the low pressure cylinder, and puts the other end of the latter in communication
with the exhaust; in another position of the valve, high pressure steam is admitted
to the other end of the high pressure cylinder, the previously admitted steam in the
first named end being made to pass into the opposite end of the low pressure
cylinder. In applying the valve to twin compound engines of the above kind the
cylinders may be either single acting or double acting, the cranks being placed
at 180°; in this case the valve and casing ports and passages are so arranged, that
the steam from the high pressure cylinder of the one engine is made to pass to the
low pressure cylinder of the other engine. In arranging such tandem engines to
act as triple expansion engines either single or twin, the high pressure cylinder is
made single acting, the piston of the high pressure cylinder being made as a trunk
piston formed in one with the piston of the low pressure cylinder, and the ports and
passages of the cylinders, valve casing and cylinder valve are so arranged that, in
the case of twin engines, the steam from the one high pressure cylinder is made to
expand first into the annular space at one end of the low pressure cylinder of the
second engine, and thence into the other end of the same cylinder, from which it
then escapes to the atmosphere or a condenser. In the case of a single triple
acting engine of this kind, there. is provided a steam chamber for receiving the

page_text: steam on its way from the high pressure cylinder to the annular space of the low
pressure cylinder. For double acting triple expansion engines we arrange the
valves and ports as will be hereinafter more particularly described.
In applying the said cylinder valve to a quadruple expansion engine, a similar
construction of engine to the above described twin triple expansion engine can be
employed, that is to say, two pairs of cylinders, each pair consisting of a large and
a small cylinder joined together, with a trunk piston for the small cylinder formed
in one with the piston for the large cylinder. In this case the ports and the
passages of the cylinders valve casing and cylinder slide valve are so arranged that
the high pressure steam, after acting in the one small cylinder is made to pass over
to the other small cylinder, which is of greater capacity, thence to the first large
cylinder and thence to the second large cylinder, which is of greater capacity. The
quadruple expansion engine may also be made with separate single or double
acting cylinders in which case the large and small cylinders would have ordinary
pistons and when double acting, the ports and passages of the valve casing and
cylinder slide valve might be duplicated.
Figure 1 of the accompanying drawings shews a vertical section of twin triple
expansion engines with tandem cylinders with valve apparatus constructed
according to the above described invention; A A¹ are two single acting high
pressure cylinders, with trunk pistons S S¹, and D D¹ are cylinders arranged
tandem with the high pressure cylinders, in which the annular spaces B B on
the upper side of the pistons T T¹ form the intermediate pressure cylinders,
while the spaces C C' on the undersides of the pistons form the low pressure
cylinders.
Between the two sets of cylinders is arranged the cylindrical valve chamber E
in which is firstly the cylindrical main slide valve F, in the tubular upper part of
which works the cylindrical expansion valve G, the former being worked by a
rod H from the main eccentric on the engine shaft while the expansion valve
is worked by the rods H'H' arranged as shewn at Figure 1 from the
expansion eccentric. The closed upper end E¹ of the valve chamber E communi-
cates by a branch opening E2 with the high pressure steam supply, and the high
pressure steam passes thence through the tubular extension F" of the main valve F
into the tubular upper end of the latter. The lining of the valve chamber is
formed with a series of circles of round holes or slots which cominunicate
respectively with an annular passage K¹ leading to the port L of the high pressure
cylinder A, an annular passage K2 leading to a chamber M for receiving the high
pressure steam from the cylinders A, A1; an annular passage K³ leading to the
port I of the high pressure cylinder A'; an annular passage K4 leading to the
port N¹ of the intermediate cylinder B'; an annular passage K³ also leading into
the chamber M; an annular passage KⓇ leading to the port N of the intermediate
cylinder B; an annular passage K' leading to the port O¹ of the low pressure
cylinder C; an annular passage K³ constituting the exhaust port of the two
low pressure cylinders and leading to the exhaust pipe U and lastly an annular
passage K' leading to the steam port O of the low pressure cylinder C.
The main valve E is formed with a number of piston like projections with spring
packing P1 P2 P3 &c., and between these are formed annular passages Q1 Q2 Q³ &c.
Of these the passages Q1 Q3 lead into the tubular interior of the valve and, being
governed by the expansion valve G, serve to admit high pressure steam to the
cylinders A A'; the passage Q2 serves to establish a communication between the
steam port L of high pressure cylinder A and the receiving chamber M;
the passage Q establishes a communication between the steam port N¹ of inter-
mediate cylinder B', and the annular chamber R in the valve; Q establishes a
communication between the steam ports N and N' of cylinders B and B¹ with the
chamber M ; Q establishes a communication between steam port N of cylinder B
with chamber R, and also a communication between the steam port O' of low
pressure cylinder C'and chamber R; Q' establishes communications between steam

page_text: ports 00¹ of C C₁ and exhaust port K³, and Q8 establishes a communication
between port O of cylinder C and the chamber R.
From the above arrangement of the ports and passages it will be seen that when
the valves F G are in the position shown on the drawing, cylinders A and B being
filled respectively with high pressure and intermediate steam, while C¹ is filled
with low pressure steam, the steam from A is passing through Q2 and K2 into
chamber M, while high pressure steam is passing from below the expansion valve
through Q and L' into cylinder A', and steam is also passing from chamber M
through K Qand N¹ into intermediate cylinder B', and lastly, intermediate steam
is passing from cylinder B through N, Q, R, Q8 and O into low pressure
cylinder C, so that pistons S' T' will now perform their down strokes, while ST,
will perform their upstrokes. On the consequent reversal of the positions of the
slides F and G, the passage Q will come opposite port L of cylinder A and will
for a time be uncovered by the slide G, so as to admit high pressure steam to this
cylinder during a certain portion of the stroke. Q² will connect L' with M so as
to exhaust cylinder A'; Q4 will connect N¹ with R so as to exhaust B'
through R, Q and O' into C', Q' will connect M with B through K and N so as
to admit the steam thereto which is coming from A', and Q' will connect C with
the exhaust port K³.
Figure 2 shews the modified arrangement of the main and expansion valves F
and G for a single triple expansion engine. A is, as before, the high pressure
cylinder, B the intermediate cylinder and C the low pressure cylinder. The
pistons S and T being at the end of upstroke, high pressure steam is about being
admitted to A through ports Q' of valve Fannular passage K' of casing E and
port L. At the same time steam which had been previously discharged from A
into receiver M of casing E, is about being admitted through port K³
passage Q2
annular passage K and port N into cylinder B. Also at the same time, the steam
which has previously passed from cylinder B into cylinder C is escaping through
port O passages K and Q to passages K³ communicating with the exhaust U, so
that the pistons S T will now perform their downstroke.
In the opposite positions of the pistons S, T, and valves F and G, the steam
passes from cylinder A. through port L passages K' Q2 port K2 into the receiver M,
while at the same time the steam passes from cylinder B through port N passage K*
port Q3 passage R, port Q', passage K and port O into cylinder C, causing the
pistons to perform their upstrokes.
Figure 3 shews the arrangement of the valves for a double acting triple
'expansion engine with tandem high and intermediate steam cylinders; A is the
double acting high pressure cylinder with piston S, arranged tandem with the
intermediate cylinder B with piston T, while the low pressure cylinder C with its
piston T is arranged on the other side of the valve F. The pistons S and T being
at the end of their upstrokes and piston T at the end of down stroke as is shewn,
the valve F is in the position for admitting high pressure steam through ports Q',
annular passage K' and port L to the upper side of piston S, the expansion
valve G G (which is only partly drawn and is assumed to be of a similar con-
struction to the previous cases) being at the same time in the position shewn
uncovering the inner face of port Q. At the same time passage Q2 of valve F has
established a communication between the underside of piston S and the receiver M
in the valve casing E, so that this receiver becomes charged with the expanded
steam from A. The receiver M is put in communication with other receivers M¹
and M2, in the casing by means of the pipe V with branches V1, V2, V³, so that all
these chambers become simultaneously charged with the steam from A. In con-
sequence hereof it will be seen that as the upper side of piston T of cylinder B is
put in communication with receiver M¹ by port N, annular passage K³ ports Q*
and annular passage R of valve F, intermediate steam will enter cylinder B.
At the same time also, the under side of piston T will have been put in
communication with the under side of piston T¹ of cylinder C by means of port N¹

page_text: annular passage K', port Q8, passage R², port Q', passage K and O', the inter-
mediate steam from cylinder B, will pass into cylinder C.
Lastly, the upper side of piston T is put in communication with passage K',
leading to the exhaust, by means of ports O, passage K*, port Q³, passage R¹ and
port Q
Pistons S and T will consequently perform their downstrokes, while piston T¹
will perform its upstroke.
On the completion of these strokes, communications will be effected by the
valves F and G as follows.
Port Q3 of valve F will commence to admit high pressure steam through expansion
valve G to the underside of piston S through annular passage K2 and port L'
the steam from the upper side of piston S will pass through port L, passage K
and passage Q2 into the receiver M, whence it will pass through branch V',
pipe V and branch V³ to receiver M², and passage K being uncovered by the
underside of the bottom piston of valve F, the steam will pass from M2 through
port N to the underside of piston T. At the same time, the upper side of piston T
will be put in communication with the upper side of piston T₁ of cylinder C, by
port N, passage K³, port Q, passage R', port Q, passage K and port O. At the
same time also, the expanded low pressure steain will escape from the underside
of piston T¹ to exhaust passage K' through port O¹, passage K, port Q³, passage R³
and port Q.
It will be understood that the branch pipe V connecting the receivers M¹ M² M³
is only put in the dotted position shewn for the sake of clearness; it is in fact
situated on the valve casing in a position at right angles to that shewn.
Figure 4 shews the arrangement of the valve F and passages of the valve casing
for a double acting triple expansion engine in which there are two low pressure
cylinders C C¹, the one being arranged tandem with the high pressure cylinder A,
while the other is arranged tandem with the intermediate steam cylinder B. The
valve F is here shewn in elevation, its construction is similar to the examples
already described and it will only be necessary to describe the manner in which it
controls the passage of steam from the high pressure cylinder A to the intermediate
cylinder B and from this to the low pressure cylinders C C¹.
The admission of high pressure steam to the two ends of cylinder A is effected
by the ports Q and Q of the valve F, these ports being controlled by an internal
expansion valve as in the previous arrangements; in the position shewn on the
drawing the steam is about to enter the upper end of A through port L, while it
is passing from the lower end of this cylinder through port L' and passage QQ+
and port N to the lower end of cylinder B. From the upper end of this cylinder
the steam is passing by port N and passages Q2 Q3 into the receiving chamber M,
which is in communication with receiving chambers MM². These chambers are
all connected together by a branched pipe as in the preceding construction, so that
as the chamber M' is put in communication with the upper side of low pressure
cylinder C through passage Q' of valve F, annular passage K' and port O, the
intermediate steam from the upper end of B will pass into the upper end of C.
At the same time also, chambers M' and M² are both put in communication with the
underside of piston T¹ of cylinder C¹, by means of passage Q, passage K' and
port P, so that intermediate steam will also enter this cylinder. The lower side
of piston T and the upper side of piston T¹ being put in communication with the
passage K, leading to the exhaust, respectively through port O', valve passage Q,
and passage K, and through port P, valve passage and passage Ko, it will
be seen that the piston S T will now perform their down strokes, and pistons B
and C' their upstrokes.
By the employment of two low pressure cylinders C C', each of about the same
capacity as the intermediate cylinder B, the inconvenience of a large low pressure
cylinder is avoided.
On the pistons arriving at the end of their strokes and the valve F in the

page_text: reverse position, high pressure steam will enter the lower end of A through L'
and Q, while the steam will pass from the upper end of A into the upper end of 13
through L Q2 Q3 and N; and from the lower end of B to receiving chamber M
through N', Q and Q; intermediate steam will pass from M' into C¹ through Q' Q'
and P, and from M2 into C through the port O¹ uncovered by the bottom piston
of F; at the same time the upper end of C will communicate with the exhaust
through O, Q and K, and the lower end of C₁ will communicate therewith
through Q
Figure 5 shews a vertical section of a quadruple expansion engine with tandem
cylinders, with the invention applied thereto. In this construction A is the high
pressure cylinder A² the second cylinder As the third, and A' the fourth cylinder.
This last cylinder is made double acting, the steam being made to pass from the top to
the underside of the piston, in order by its further expansion, to take the load off the
crank on the upstroke. E is, as before, the lining to the valve chamber, having rings
of holes or slots communicating with the several annular passages in the body of
the chamber; F is the main cylindrical valve and G is the expansion valve.
E2 is the high pressure steam supply to the extension E of the valve chamber E,
from which it enters the extension F' of the main valve F, and is admitted to the
cylinder A by the ports Q' of the valve F when these communicate with the port L
of the cylinder A' by means of the annular passage K' communicating with such
port, the admission of steam being controlled by the expansion valve G. In the
position of the pistons and valves shewn on the drawing, the piston S of the high
pressure cylinder has just completed its stroke, and the steam is just about to pass
into the second cylinder A2, for which purpose the port Q2 of the valve F is in
communication with the passage K', and is about to establish a communication
through annular passage R and ports Q with passage K2 and port L' of
cylinder A². At the same time, the steam which has previously passed from
cylinder A2 to cylinder A³ is about to pass thence into cylinder A through port N,
annular passage K³ port Q annular passage R' port Q annular passage K and
port N¹ into cylinder A on the upper side of piston T¹. At the same time also,
steam which had previously been admitted from the upper side to the underside of
piston T¹ passes to the exhaust outlet U through port O and annular passages Q7
and Ke.
For a non-condensing engine the underside of piston T might also be put in
communication with port Ŏ of cylinder A4 by a passage connecting with K³, and
thus by admitting low pressure steam under piston T, to also balance the weight of
pistons S and T when required. On the return stroke of piston T such steam is merely
transferred to cylinder A during the upstroke of its piston T'.
On the valve F being moved into the opposite position to that shewn on the
drawing, high pressure steam is admitted to cylinder A¹ through ports Q' and
passage Kas before described, while at the same time, the steam passes from
cylinder A through port L', annular passage K2 ports Q2 passage R, port Q,
passage K³ and port N into cylinder A³, and at the same time also steam passes
from the upper side of piston T¹ through port N¹ passage K* port Q passage R¹
port Q passage K³ and port O to the underside of piston T'.
Fig. 6 shews the arrangement of the valve F and ports and passages for a
double acting quadruple expansion engine with tandem cylinders. A' is the high
pressure cylinder A² the second cylinder, A³ the third and A' the fourth.
Pistons S and T being at the end of upstroke and S' and T at the end
of downstroke, the valve F is in the position for establishing communications as
follows.
High pressure steam is entering the upper end of A¹ through Q1 K¹ and L, while
the expanded steam is passing from the lower end of A' into the lower end of A2
through L K Q'R' QK³ and N'; steam is also passing from the upper end of A
to receivers M M₁ M² (connected by a branched pipe as before described)
through N K² Q2 R Q³; steam is also passing from receiver M¹ into the upper end

page_text: of A' through Q and O; while it is passing from the lower end of A³ to the lower
end of A' through O¹ K³ Q R³ Q'K' and PI; and lastly; steam is passing from the
upper end of A4, to the exhaust passage K through P K Q7 R2 and Q. From
the previous descriptions it will be readily understood how the valve F controls
the passage of the steam to the several cylinders on its reversal when the several
pistons are at their other end strokes.
The expansion valve is contained in the upper part of the valve F and controls
the passages Q' and Q as previously described.
Although we have described the double acting triple and quadruple expansion
engines as being arranged vertically, it is to be understood that they may also be
arranged in horizontal positions.
In applying the improved construction of valves to a single acting compound
tandem engine, the arrangement of the ports and passages would be similar to that
described with reference to the triple expansion engine at Fig. 2, with the exception
that the bottom port O of cylinder D is omitted, as are also the passages K and Q*
the passage R and port Q³ being so formed as to establish the communication
between port N and passage K' and exhaust passage K' when piston T is at end of
downstroke.
In applying the said valves to double acting compound engines with tandem
cylinders whether single or twin, the arrangements would be similar to that of the
triple expansion engine described with reference to Fig. 1, with the necessary
modifications whereby firstly the cylinders A (or cylinders A A¹) would be made
separate from D (or D D¹) and would contain an ordinary piston (or pistons)
instead of a trunk piston, secondly the lower end of A (or A A') would have a port
controlled by corresponding passages in the valves F and G so as to alternately
establish communication with the high pressure steam supply and with the
receiver M while the ports at each end of the cylinder D (or cylinders D D¹)
would be made to communicate alternately with the receiver M and with the
exhaust.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In combination with the cylinders of a pair of triple expansion tandem engines
the arrangement of a cylindrical main slide valve F working in a valve chamber E,
having passages K¹ K² K³ K¹ K³ K® K' K³ K³ communicating respectively with the
ports of the cylinders A A, B B, C C with a receiving chamber M and with the
exhaust, the valve F being formed with ports and passages Q' Q2 Q3 Q4 Q° Q° Q² Q³
and R which together with the said passages in the casing E establish com-
munications between the high pressure steam supply and the cylinders A A',
between the cylinders A A' and the chamber M, between the chamber M and the
cylinders B B between the cylinders B B and the cylinders C C and between
these and the exhaust, substantially as described with reference to Fig. 1 of the
drawings.
2. In combination with the cylinders of a single triple expansion tandem engine,
the arrangement of a cylindrical main slide valve F working in a valve chamber E
having passages K' K² K³ K K K communicating respectively with the ports of
the cylinders A B and C, with the receiving chamber M and with the exhaust, the
valve F being formed with ports and passages QQQQQ' R which passages,
together with the said passages in the valve casing, establish communications
between the high pressure steam supply and the cylinder A, between the cylinder A
and the chamber M, between the chamber M and the cylinder B, between the
cylinder B and the cylinder C and between this and exhaust, substantially as
described with reference to Fig. 2 of the drawings.
3. In combination with the cylinders ABC of a double acting triple expansion
tandem engine, the arrangement of a cylindrical main valve F working in a valve

page_text: chamber having passages K' K2 K3 K K K K communicating respectively with
the ports of the cylinders A B and C and with the exhaust, and having also receiving
chambers M MM² for the intermediate steam communicating freely with each
other, the valve F being formed with ports and passages QQQ³ Q+ Q³ Qª Q² Q³,
R R R2, which, together with the said passages in the valve casing, establish
communications between the high pressure steam supply and the two ends of
cylinder A, between cylinder A and the chambers M M M² between these
chambers and the two ends of cylinder B, between the two ends of this cylinder
and the two ends of cylinder C, and between the latter and the exhaust, substantially
as described with reference to Fig. 3 of the drawing.
4. In combination with the cylinder A B C C¹ of a double acting triple expansion
tandem engine, the arrangement of a cylindrical main valve F working in a valve
chamber having passages K' K2 &c. communicating respectively with the ports of
the cylinders and with the exhaust, and having also receiving chambers M M¹ M²
for the intermediate steam, communicating freely with each other, the valve F
being formed with ports and passages Q¹² Q³ &c. which together with the said
passages in the valve casing, establish communications between the high pressure
steam supply and the two ends of cylinder A, between cylinder A and the
two ends of cylinder B; between the two ends of this cylinder and the
chambers M Mi M² between these chambers and the two ends of cylinders C and C',
and between the two ends of these cylinders and the exhaust, substantially as
described with reference to Fig. 4 of the drawings.
5. In combination with the cylinders of a quadruple expansion engine, the
arrangement of a cylindrical main slide valve F working in a valve chamber E
having passages K K K K K K communicating respectively with the ports of
the cylinders A' A2 A3 A', and with the exhaust, the valve F being formed with
passages QQQ³ Q* Q' Q' Q' and passages R and R', which together with the
said passages in the casing E establish communication between the high pressure
steam supply and the cylinder A', between the cylinders A1 and A2, between
cylinders A2 and A³, between cylinder A³ and the top of cylinder A, between the
top of A and the bottom thereof, and between the bottom of A and the exhaust,
substantially as described with reference to Fig. 3 of the drawings.
6. In combination with the cylinders of a double acting quadruple expansion
engine, the arrangement of a cylindrical main slide valve F working in a valve
chamber E having passages K' K2 &c. communicating respectively with the ports
of the cylinders A1 A2 A3 A4, and with the exhaust, and having also receiving
chambers M M' M², communicating freely with each other, the valve F being
formed with ports and passages Q1 Q2 &c. which together with the said passages
in the valve casing establish communications between the high pressure steam
supply and the two ends of cylinder A', between the cylinders A' and A², between
the cylinder A2 and receivers M M M² communicating with each other, between
the said receivers and the cylinder A³, between this cylinder and cylinder A* and
between this cylinder and the exhaust, substantially as described with reference to
Fig. 6 of the drawings.
7. In combination with the cylinders of a single or twin compound tandem
engine, the arrangement of a cylindrical main slide valve F working in a valve
chamber E having passages K' K2 &c. communicating respectively with the port of
the cylinders AD (or A A' D D¹) and with the exhaust, and having also a
receiving chamber M, the valve F being formed with ports and passages QQ² &c.
which together with the said passages in the valve casing establish communications
between the high pressure steam supply and the two ends of cylinder A
(or cylinders A A') between this cylinder (or these cylinders) and the receiver M,
between. this receiver and the two ends of cylinder D (or cylinders D D¹) and
between this cylinder (or these cylinders) and the exhaust, substantially as
described with reference to. Fig. 1.
.8.. In combination with the cylindrical slide valves F referred to in the preceding

page_text: claims, the use of expansion valves G, arranged as described for controlling the
admission of the high pressure steam to the high pressure cylinder of the engine,
through the ports of the said valves F, substantially as described.
Dated this 2nd day of July 1800
ABEL & IMRAY,
Agents for the Applicants.