Improvements in Compound Steam Engines.
Year: 1890

page_text: Date of Application, 11th June, 1890
Complete Specification Left, 11th Mar., 1891-Accepted, 11th June, 1891
PROVISIONAL SPECIFIC
Improvements in Compound Steam Engines.
I, JOHN PITT BAYLY, of 18 Fulham Place, Paddington, in the County of
London, Patent Agent, (a communication to ine from abroad by John Riekie, of
Lahore, India, Locomotive Superintendent,) do hereby declare the nature of this
invention to be as follows:-
This invention relates to compound engines, and it has for its object to provide
for the better running of them than hitherto.
By this invention two high pressure cylinders are provided which are arranged
with a low pressure cylinder between them. A steam chest forms part of the low
pressure cylinder and which steam chest is provided with a port leading to each
high pressure cylinder and two ports leading to the low pressure cylinder. Pipes
lead from the ports of the low pressure cylinder to the high pressure cylinders.
The steam chest contains a hollow cylindrical slide valve which is provided at
suitable distances apart with annular grooves which are connected by apertures
with the interior of the valve.
יד
1000
J. P. BAYLY,
Applicant.
COMPLETE SPECIFICATION.
Improvements in Compound Steam Engines.
I, JOHN PITT BAYLY, of 18 Fulham Place, Paddington, in the County of
London, Patent Agent, do hereby declare the nature of this invention (a com-
munication to me from abroad by John Rickie, formerly of Lahore, but now
residing at Quetta, Beluchistan, India, District Locomotive Superintendent,) to
be particularly described and ascertained in and by the following statement :-
The object of the invention is to provide a new and improved compound engine
which is simple and durable in construction and very effective in operation, utilizing
the steam to the fullest advantage.
The invention consists in certain parts and details and combinations of the same,
as will be fully described hereinafter, and then pointed out in the claims.
Reference is to be had to the accompanying drawings, forming a part of this
Specification, in which similar letters of reference indicate corresponding parts in
all the figures.
Figure 1 is a sectional side elevation of the improvement.
Fig. 2 is a transverse section of the same on the line of Fig. 1.
Fig. 3 is a sectional side elevation of a modified form of the improvement, and
Fig. 4 is a side elevation of the valve for the same.
The compound engine A, as illustrated in Figs. 1 and 2, is provided with the
two high-pressure cylinders B and C, between which is held a low-pressure
In the
cylinder D, all three cylinders being placed in line with each other.
cylinders B C D are held to slide pistons B', C¹, and D¹, respectively, all secured
to a piston-rod E, connected in the usual manner with the main driving-shaft of the
engine.
Into the inner ends of the high-pressure cylinders B and C lead the live-steam
ports a and b, respectively, also opening into the ends of the steam chest F,

page_text: preferably of cylindrical form, and containing a hollow cylindrical valve G, con-
nected with the valve rod H, operated in the usual manner from the main
driving-shaft of the engine.
Into the ends of the steam chest F lead pipes F1 F2, connected with the steam
dome of the boiler, so as to supply the said steam chest and in the middle of the
same extends the exhaust-pipe I, provided with two channels I and 12, leading to
the interior of the steam-chest F. The latter is also connected near its middle by
the ports and d with the ends of the low-pressure cylinder D. From the said
ports c and d lead the pipes J and J', respectively connected with the ports e and
respectively leading to the outer ends of the high-pressure cylinders B and C,
respectively.
In the periphery of the cylindrical valve G are arranged annular grooves K, K',
and K, connected by apertures K³ with the interior of the said valve G. Between
the annular grooves K and K² is formed an annular groove L, adapted to register
with the port and the branch I of the exhaust-pipe 1. A similar annular
groove L is formed in the periphery of the valve G between the annular
grooves K and K² and the said annular groove L' serves to connect the port d
with the branch 12 of the exhaust.
The operation is as follows: When the engine is in the position shown in Fig. 1,
the live steam from the boiler passes into the right-hand end of the steam-chest F,
and passes from the latter through the port into the inner end of the high-pressure
cylinder C to exert its pressure against the piston C'. The latter is thus forced
outwards in the direction of the arrow a', carrying the pistons B and D' in the
same. direction. Any steam in front of the piston C passes through the port finto
the pipe J, and from the latter into the port d, from which the exhaust-stcam
passes into the annular groove L' and into the exhaust-pipe 1. Steam in front of
the piston D¹ passes through port d and the annular groove L' into the exhaust-
pipe I with the exhaust-steam from the high-pressure cylinder C. The exhaust-
steam in front of the piston B in the high-pressure cylinder B passes through the
port a into the annular groove K, and from the latter through the openings K³ into
the interior of the valve G, from which the steam passes through the openings K³
into the annular groove K2, and from the latter into the port c, from which it passes
to the left-hand end of the piston D' thus exerting its force against the piston D1
and assisting the live steam acting against the piston C³, as above described, to
move the piston-rod E in the direction of the arrow a¹. Part of the exhaust steam
from the cylinder B, which passes into the port e, as above described, passes from
the latter through the pipe J and the port e to the left-hand end of the piston B¹.
When the pistons B¹, D¹, and C are at the ends of their strokes, the valve G is
shifted in the usual manner, so that the port is cut off from the right-hand end of
the steam-chest F, while the left-hand end of the latter connects by the port a with
the inner end of the high-pressure cylinder B. The live steam from the steam-
chest F, passing through the port a into the cylinder B, now exerts its pressure
against the piston B' and forces the same with the pistons D¹ and C¹ in the inverse
direction of the arrow a'. The steam on the left-hand end of the piston B' is now
exhausted through the port e, the pipe J, the port c, and the annular groove Linto
the branch of the exhaust-pipe I. The steam on the left-hand end of the
piston D also passes into the port c and passes into the exhaust-pipe I by means of
the annular groove L. The steam on the left-hand end of the piston C' passes
through the port into the annular groove K', and from the latter by its
openings K³ into the interior of the valve G. The steam then passes from the
interior of the valve G into the annular groove K², now connecting with the port d,
so that the said steam passes to the right-hand end of the cylinder D and exerts its
power against the piston D', assisting in moving the piston-rod E in the inverse
direction of the arrow a'.
In the modification illustrated in Figs. 3 and 4 the inlet-ports a and b for the
high-pressure cylinders B and C discharge into the said cylinders at their outer

page_text: ends instead of at their inner ends, as previously described with reference to Fig. 1.
The other ports e and lead from the inner ends of the cylinders B and C and
discharge into the steam-chest F made of two parts, containing the heads G¹
and G2 of the valve G, said heads being connected with each other by a hollow
stem G. From the steam-chest F lead the ports c and d to the ends of the
cylinder D. In the head of the valve G is formed an annular groove K,
operating over the inlet-port a, and permitting the steam to pass into the interior
of the valve-heads G and G2 and the connecting hollow tube G³. In the head G¹
is further formed an annular groove K³, connected with the interior of the head by
the apertures K³. Said annular groove K operates over the port c. Between the
annular grooves K and K is formed an annular groove L, adapted to connect the
port e with the channel I' of the exhaust I. The arrangement of the head G³ of
the valve G is similar to that of the head G', previously described. The head G'
has the annular grooves K' and K³, and the annular groove L', operating over the
ports, d, and, and the exhaust channel [*. The operation is similar to the one
described in reference to Fig. 1, with the exception that the live steam entering
the steam-chest F passes through the ports a and b into the outer ends of the
cylinders B and C, instead of at the inner ends as described with reference to
Fig. 1.
It will thus be seen that boiler-pressure steam is allowed to do duty for one
stroke on the piston in the high-pressure cylinder, after which said cylinder is
converted to a steam-chamber on the return stroke of the piston while the steam is
doing a second duty-that is, expanding in another cylinder-and so on until all
useful pressure of the steam is used up, and is then allowed to escape to the
atmosphere or to a condenser. It will further be seen that double power is exerted
by the force of the steam. The cylinders can be greatly reduced in size so as to
save considerable steam, at the same time developing a large amount of power. It
will further be seen that an equal power is exerted on the crank-arms of the main
driving-shaft at all grades of expansion, compounding being done on each crank
separately.
In this engine a vacuum is produced on all pistons when the steam is at work on
the opposite side.
No waste of steam is possible in this engine, and consequently there is no
necessity for spark-arresters when the machine is applied on locomotives. When
the engine is started, the valve G is so shifted as to admit steam to the low-pressure
cylinder, if it is deemed necessary.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In a compound engine, the combination, with two high-pressure cylinders and
a low-pressure cylinder between the said high-pressure cylinders, of a steam-chest
provided with a port leading to each high-pressure cylinder and with two ports
leading to the low-pressure cylinder, pipes leading from the ports of the low-
pressure cylinder to the high-pressure cylinders, and a hollow cylindrical valve
provided with annular passages, some of which communicate with the interior of the
same, substantially as herein shown and described.
2. In a compound engine, the combination, with two high-pressure cylinders and
a low-pressure cylinder, of a steam-chest provided with ports leading to the said
cylinders, and the hollow cylindrical valve G, provided with the annular grooves K
KK, connected by apertures K³ with the interior of the valve, and the inter-
mediate annular grooves L L', substantially as herein shown and described.
3. In a compound engine, the combination, with two high-pressure cylinders and
a low-pressure cylinder, of a steam-chest provided with a port leading to each high-
pressure cylinder and with two ports leading to the low-pressure cylinder, pipes
connecting the passages leading from the steam-chest to the low-pressure cylinder

page_text: with the high-pressure cylinders, and the hollow cylindrical valve G, provided with
the annular grooves K K K², connected by apertures K³ with the interior of the
valve, and the annular grooves L L' between the grooves K and K and K' and K'
respectively, substantially as described.
131
__ 1901
J. P. BAYLY,
Applicant.