Improvements in High-speed Compound Engines.
Year: 1888

page_text: Date of Application, 20th Dec., 1888
Complete Specification Left, 20th Sept., 1889-Accepted, 26th Oct.,* 1889
PROVISIONAL SPECIFICATION.
Improvements in High-speed Compound Engines.
WILLIAM CHILTON of 177 Upland Road, East Dulwich London, engineer do
hereby declare the nature of this invention to be as follows:-
In describing my improvements in high-speed engines I shall for greater clearness
describe one modification of my invention suitable for a vertical tandem triple-
expansion engine it being understood that with the modifications usually made
in engine work the improvements may be taken as applicable to horizontal and
other engines as well as to those of the vertical type and that by augmenting the
number of cylinders and suitably proportioning their volumes the engine can be
made for quadruple or even higher expansions. It is also to be understood that the
passage of the steam through the cylinders is regulated by suitable valves much in
the usual way.
My invention consists in attaching a single-acting high-pressure cylinder to a
double-acting low-pressure cylinder tandem fashion in such a way that steam being
admitted to the high-pressure cylinder it is there expanded and then exhausted
into a receiver from which receiver at the proper time it is admitted and expanded
in the top end of the low-pressure cylinder. From the top end of this cylinder
the steam is exhausted into a receiver through which it passes on its way to the
bottom end of the low-pressure cylinder and from this end of the low-prossure
cylinder it is exhausted either into the atmosphere or into a condenser. The steain
is thus expanded three times during its passage through the cylinders.
I shall call the first cylinder the high-pressure cylinder, the top side of the
second cylinder the intermediate cylinder and the bottom side of the second
cylinder the low-pressure cylinder.
The connection between the pistons and the crank is made in the usual way.
It will be evident from the description that the effective area of the intermediate
cylinder is less than the area of the low-pressure cylinder by an amount equal to
the area of the high-pressure cylinder, thus for example if the ratio of the area
of the high-pressure cylinder to that of the intermediate cylinder is as one to two,
that of the high-pressure cylinder to the low-pressure cylinder will be as one to
three, therefore in arranging the cylinders as described and passing the steam
through the cylinders in the manner indicated I in effect expand the steam in
three cylinders of different volumes and obtain what is usually termed triple-
expansion.
By this arrangement in addition to obtaining a convenient though simple form
of triple-expansion engine I claim what I consider of greater importance in high-
speed engines, that with this arrangement of cylinders the resultant downward
pressures during the upstroke of the pistons etc. are sufficient to overcome the
inertia of the moving parts which tends to make the pistons rods with their brasses
leave the crankpin and the crossheadpin thus causing a severe shock when the
steam pressure forces these together again.
Having thus in a general way set forth the action of the steam in its passage
through the cylinders, I shall now more particularly explain its action during one
revolution of the crank. Suppose the pistons to be at the top of their stroke and
steam to be admitted from the boiler into the high-pressure cylinder.
The pistons move downwards, the steam is cut off and then expanded until the end
of the stroke. During the return stroke the steam is exhausted from the high-
pressure cylinder into a receiver where it is stored up ready for use in the inter-
mediate cylinder at the next stroke, as is the usual method in single-acting tandem
compound engines.

page_text: When the pistons were starting on the downstroke the intermediate cylinder was
taking steam, which had been stored up during the previous backstroke, from the
receiver abovementioned. The downstroke being completed and the pistons at the
bottom of their stroke, the steam in the intermediate cylinder is passed during
the upstroke of the pistons, through a second receiver into the low-pressure cylinder
and is compressed into this receiver by the intermediate piston when the low-
pressure cylinder ceases to take steam. The steam now shut up in the low-pressure
cylinder is expanded in the usual way and is finally exhausted either into the
atmosphere or into a condenser.
The back pressures which during the upstroke act against the pistons I utilize
in counteracting the inertia of the moving parts while moving upwards to complete
the return stroke.
I claim that with this combination of a single-acting high-pressure cylinder and
a double acting low-pressure cylinder, I can construct a triple-expansion engine of
simple form and that I can by suitably arranging the valve-gear set up back
pressures and compress the steam and so obtain a downward force sufficient to
overcome the inertia of the moving masses as already explained also as will be
understood from the description the condenser acts on the downward stroko and
on the underside of the low-pressure piston instead of on the upward stroke and
the top side of the piston as in ordinary single-acting engines so that in my
arrangement of cylinders the engine can be worked equally well either with or
without condenser as this has no tendency to pull the pistons and their connections
off the crankpin and crossheadpin this being the action of the condenser when
acting during the upward stroke and on the top side of the piston.
The valves may be actuated by eccentric or other gear and the cut off arranged
to take place automatically or be controlled by hand or the engine may be
regulated by an ordinary throttle valve and governor.
I have described a triple-expansion engine made by arranging a single-acting
high-pressure cylinder over a double-acting low-pressure cylinder. In a similar
manner by arranging a single-acting high-pressure cylinder over a single acting
intermediate pressure cylinder and this again over a double-acting low-pressure
cylinder I obtain a quadruple-expansion engine and so on to higher expansions
the action being similar to that in the triple-expansion already described the con-
denser acting in both cases on the underside of the last piston and during the
downstroke.
I can combine two or three such tandem engines side by side on to as many
cranks the cranks being placed at any convenient angle or angles to one another.
Dated this 19th day of December 1888.
WILLIAM CHILTON.
COMPLETE SPECIFICATION.
Improvements in High-speed Compound Engines.
I, WILLIAM CHILTON, of 177, Upland Road, East Dulwich, London, 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, and accompanying drawing, (that is to say) :-
My invention relates to high speed Engines, and is applicable to vertical, horizontal,
or other engines. In the accompanying drawing which is in illustration of the inven-
tion, it is shewn applied to a vertical tandem triple expansion Engine, but it is to be
understood that it is also applicable to horizontal and other Engines, and also that by
increasing the number of cylinders and suitably proportioning their relative capacities,
the invention may be applied to quadruple or even higher rates of expansion.
The passage of the steam through the several cylinders is regulated by suitable
valves constructed and operated in the ordinary well known way.
My invention consists in attaching (tandem fashion) a single acting high pressure

page_text: cylinder to a double acting low pressure cylinder in such a way that steam is admitted
to the high pressure cylinder and is then first expanded and is then exhausted into
a receiver from which at the proper time it is admitted to the top end of the low
pressure cylinder where it is again expanded.
From the top end of this cylinder the steam is exhausted into a second receiver
through which it passes on its way to the bottom end of the low pressure cylinder and
is again expanded and from this end of the low pressure cylinder it is finally exhausted
into a condenser or discharged into the atmosphere.
The steam is thus expanded three times during its passage through the cylinders.
For the purpose of description, I will call the first cylinder the high pressure
cylinder, the upper side of the second cylinder the intermediate cylinder, and the lower
side of the second cylinder the low pressure cylinder.
The connection between the pistons and the crank is made in the usual way.
It will be evident from the above description that the effective area of the inter-
mediate cylinder is less than the area of the low pressure cylinder by an amount
equal to the area of the high pressure cylinder.
For instance, if the ratio of the area of the high pressure cylinder to that of the inter-
mediate cylinder is as one to two, that of the high pressure cylinder to the low pressure
cylinder will be as one to three; so that in arranging the cylinders as described and
passing the steam through them in the manner indicated, 1, in effect, expand the
steam in three cylinders of different capacities, and so obtain what is usually termed
triple expansion.
By this method of arrangement, in addition to obtaining a convenient and simple
form of triple expansion Engine, I also obtain the advantage that with this arrange-
ment of cylinders the resultant downward pressures during the upstroke of the piston's
are sufficient to overcome the momentum of the moving parts, which tends to cause
the piston rods and connecting rods with their brasses to leave the crank pin and
the crosshead pin thus causing a severe shock when the steam pressure forces them
together again.
Having thus set forth generally the action of the steam in its passage through the
cylinders, I shall now proceed to explain more particularly its action during one
revolution of the crank, reference being had to the accompanying drawing, which is a
vertical section through the cylinders and valves. a is the upper cylinder, and 6 the
lower cylinder, c being the upper piston and d the lower one, connected together by
the trunk c', und e being the piston rod which passes through a stuffing box f and
drives the crank pin g in the usual way by means of a connecting rod, not shewn in
the drawing. h is the steam admission valve, and i is the distributing valve, these
valves being worked by excentrics k, or other convenient devices in the usual way.
Supposing the pistons to be at the top of their stroke as shewn, and steam to be
admitted to the inlet pipe from a boiler. The valve h allows the steam to pass
through the port o to the upper end of the cylinder a above the high pressure piston c,
and accordingly the pistons move downward. After completing a determined part of
their stroke, the steam is cut off by the valve h and is expanded in the cylinder a
until the end of the stroke. During the return, or upstroke, the steam in the
cylinder a is allowed to pass by the valve h into a suitable receiver m where it is
stored up ready for use in the intermediate cylinder (consisting of the upper part of
the cylinder ) above the piston d, at the next stroke, in the method ordinarily
practised in single acting tandem compound engines.
When the pistons were commencing their down stroke, the intermediate cylinder
was taking steam above the piston d, which had been stored up during the previous
upstroke, from the receiver m. The downstroke being completed and the pistons at
the bottom of their stroke, the steam in the intermediate cylinder, above the piston d,
passes by means of the valve i, during the upstroke of the pistons, into a second
receiver Pr and from it into the low pressure cylinder below the piston d and when at
a certain point admission is cut off from this cylinder, it is compressed by the con-
tinuing stroke of the pistons into the receiver p. The steam in the low pressure
cylinder bis at the same time expanded in the usual way and at the end of the stroke
.

page_text: is finally exhausted through the valve i to the exit passage or pipe r, whence it passes
either to a condenser or to the atmosphere.
It will be seen that the back pressures above the pistons during their upstroke are
utilized to counteract the momentum of the moving parts whilst they are moving up to
complete their upstroke.
By the novel combination in the manner described of a single acting high pressure
cylinder with a double acting low pressure cylinder, it will be seen that I obtain a
triple expansion Engine of very simple form, whilst by suitably arranging the valve
gear I obtain back pressures and compress the steam so as to obtain a downward force
upon the pistons sufficient to overcome the momentum of the moving masses as
already explained.
Also, the condenser acts during the downward stroke upon the lower side of the low
pressure piston, instead of upon its upper side and during its upstroke as is the case
in ordinary single acting Engines, so that in my improved arrangement of cylinders
the Engine can be worked equally well either with or without a condenser, as the vacuum
in the latter has no tendency to pull the pistons and their connections from contact
with the crank pin and crosshead pin during the upstroke, as is the case in such
Engines when the condenser is connected with the upper side of the piston during the
upstroke.
The valves may be actuated by excentrics or other gear in the usual way, and the
cut off may be effected in such manner as to be varied automatically or may be
controlled by hand; or the Engine may be regulated by an ordinary throttle valve
and governor.
I have described and shewn a triple expansion Engine made by arranging a single
acting high pressure cylinder, above a double acting low pressure cylinder.
In a similar manner by arranging a single acting high pressure cylinder above a
single acting intermediate pressure cylinder, and this again above a double acting low
pressure cylinder, I obtain a quadruple expansion Engine, and so on in a similar way
to higher expansions if required, the condenser acting in every case upon the lower
side of the last piston and during the downstroke for the purpose already described.
a
Two or more such tandem Engines may be arranged side by side, driving
similar number of cranks which are placed at any convenient angle or angles to each
other.
I do not confine myself to the precise form and arrangement of the several parts of
the Engines, which may be varied more or less to suit the different circumstances and
conditions under which they are to be used, but
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. The combination of the single acting small cylinder and piston, the double
acting large cylinder and piston, and the valves, arranged and operating so that steam
is admitted above the small piston, is then cut off, and on the return stroke is admitted
to a receiver from which on the next down stroke it is admitted above the large piston
and is again expanded, and is then exhausted into a second receiver through which it
passes at the next upstroke to the lower side of the large piston, being cut off at a
certain part of the stroke and the remainder being compressed by the continuing
upstroke of the large piston into the second receiver, the expanded steam below the
piston passing during the next down stroke into a condenser or into the air, all sub-
stantially as and for the purposes described and illustrated.
2. The combination with the two cylinders and pistons described in the first claim,
of one or more additional cylinders and pistons, for the purpose of obtaining quadruple
or higher rates of expansion, substantially as herein described.
Dated this 20th day of September 1009.
EDWARDS & CO.,
35, Southampton Buildings, Chancery Lane, London, Agents for the Inventor.
EDWARDS & Co.,
35, Southampton Buildings, Chancery Lane, London, Agents for the Inventor.