IMPROVEMENTS IN APPARATUS FOR THE PRO- DUCTION OF MOTIVE POWER JOINTLY BY THE ELASTIC FORCE OF PRODUCTS OF COMBUSTION AND OF STEAM OR VAPOUR, PART OF WHICH IS APPLICABLE WHEN THE FORMER ALONE IS USED
Year: 1876

page_text: LETTERS PATENT to Matthew Piers Watt Boulton, of Tew Park, Oxfordshire,
Esquire, for the Invention of "IMPROVEMENTS IN APPARATUS FOR THE PRO-
DUCTION OF MOTIVE POWER JOINTLY BY THE ELASTIC FORCE OF PRODUCTS
OF COMBUSTION AND OF STEAM OR VAPOUR, PART OF WHICH IS APPLICABLE
WHEN THE FORMER ALONE IS USED."
Sealed the 19th December 1876, and dated the 27th September 1876.
PROVISIONAL SPECIFICATION left by the said Matthew Piers Watt Boulton
at the Office of the Commissioners of Patents on the 27th September 1876.
MATTHEW PIERS WATT BOULTON, of Tew Park, Oxfordshire, Esquire. "IMPROVE-
MENTS IN APPARATUS FOR THE PRODUCTION OF MOTIVE POWER JOINTLY BY THE
ELASTIC FORCE OF PRODUCTS OF COMBUSTION AND OF STEAM OR VAPOUR, PART
OF WHICH IS APPLICABLE WHEN THE FORMER ALONE IS USED.'
"
This Invention has for its object improvements in apparatus for the production of
motive power jointly by the elastic force of products of combustion and of steam or
vapour, part of which is applicable when the former alone is used.
In one form of apparatus constructed according to this Invention, the steam or
vapour employed is generated by the heat of the products of combustion while per-
forming work. In this case I operate with more than one cylinder. In the
following description I shall suppose two cylinders to be employed and steam to be
the vapour made use of; one of the cylinders has a higher and one a lower tempe-
rature. I shall speak of these as the hot and cool cylinders.
The hot cylinder is fitted at both ends with apparatus for the introduction and
ignition of the inflammable mixture, which apparatus may be of any known kind.
This cylinder or a portion of it is surrounded by water which is contained within a
boiler. Passages are provided by which the steam space of this boiler communicates
with both ends of the cylinder so that steam from the boiler enters either end of
the cylinder at the proper time.
The heated elastic fluid working in the hot cylinder imparts heat to the water in
the boiler and generates the steam which afterwards is used in the cylinders. I
prefer that this steam should be generated at a pressure equal to the highest
pressure produced in the hot cylinder by the combustion of the inflammable
mixture.

page_text: The cool cylinder is connected with the hot cylinder in the same way in which
the low-pressure cylinder of a steam engine is connected with the high-pressure one,
so that the elastic fluid which has expanded to a certain degree in the hot cylinder,
passes thence into the cool cylinder, and there finishes its expansion.
The operations are as follows:-The inflammable fluid mixture is introduced
behind the piston in the hot cylinder and is ignited, whereupon sudden rise of
pressure takes place; simultaneously or nearly so a valve opens the communication
between the hot cylinder and boiler, and steam enters from the boiler and mixes
with the hot products of combustion. After a certain determinate quantity of steam
has entered the cylinder its admission is cut off. When the piston advances to a
certain point the hot working fluid enters that portion of the cylinder which is
surrounded by the water of the boiler, and in passing through this portion it imparts
heat to the water in the boiler through the metal of the cylinder and generates
steam, which rises to the steam space of the boiler. While the piston is thus urged
behind by the heated mixture of products of combustion and steam, it drives out in
front of it heated fluid which has performed work into the second or cool cylinder,
in which it continues to expand and performs further work. The piston having
reached the end of its stroke the valve through which the elastic fluid was passing
into the cool cylinder is closed and a valve opens communication between the elastic
fluid which has just propelled the piston and the cool cylinder. The same operations
are then repeated for the return stroke.
The fluid which acts in the cool cylinder is discharged at the end of each stroke,
either into the air or into a refrigerator maintained at low pressure from which it is
extracted by a pump. When such a refrigerator is used it is provided with a
chamber for collecting water of condensation which is removed by a small pump.
The quantity of steam introduced into the cylinder is adjusted by means of a
regulator, by means of which the area of the passage which supplies steam to the
cylinder is increased or diminished at pleasure.
Generally not more steam should be introduced than is necessary in order to
render the final temperature of the exhaust as low as is desired. More than one
hot cylinder may be provided in connection with one cool cylinder.
The piston rod and piston of the hot cylinder may be cooled by water commu-
nicating with the water in the boiler and assisting to heat it. A small portion of
water may be introduced into the hot cylinder through the piston or piston rod
serving to generate a portion of the steam used.
The construction may be modified by introducing the steam generated in the space
which surrounds the hot cylinder into the second cylinder. In this case a hotter
fluid acts in the hot cylinder for the generation of steam. But generally I prefer the
first construction in order that the steam may act at higher pressure. Or again the
steam generated may be employed in a separate cylinder or in any mode desired for
the production of motive power.
In order to regulate the generation of steam I provide means for raising and
lowering the level of the water in the boiler by the motion of a body within it in
a manner explained by me in a former Specification, No. 1108, in the present year.
In this way a greater or a less portion of the surface of the cylinder is brought into.
contact with the water of the boiler as may be desired. The regulation may be
made self-acting by means of any of the contrivances by which variations of pressure
are employed to cause motion of bodies.
Provision is made for applying independent heat to the water by means of an
auxiliary boiler, so that steam can be got up before the engine is started, and so that
when the engine is not at work the steam pressure can be maintained.
The admission of steam from the boiler into the cylinder may be made use of to
start the engine.
In another form of apparatus constructed according to this Invention, the steam
employed is generated in a boiler, not heated by the products of combustion
which perform work, but by an independent source of heat. The cylinder in which
this steam works is fitted at either end with valve apparatus for the introduction

page_text: and ignition of the inflammable mixture. At the commencement of each stroke the
inflammable mixture is introduced into the cylinder and ignited. Simultaneously,
or almost so, the steam enters from the boiler and mixes with the hot products of
combustion, and the mixed fluid performs work in the cylinder.
The admixture of the hot products of combustion superheats the steam and
enables it to expand without condensation.
The mixed fluid may be treated like the steam of a steam engine; it may either
pass to a condenser or a refrigerator at low pressure or be discharged into the air.
In this construction as in the preceding one a regulator may be used in order to
adjust accurately the quantity of steam admitted.
One cylinder may be employed in this construction, the whole expansion of the
fluid taking place in this. But successive cylinders for expansion as are frequently
used in steam engines may be employed if desired.
When apparatus of this kind is is used the steam may be generated by coal or
other fuel in the ordinary way, whilo as an ingredient of the inflammable mixture
coal gas may be used, or inflammable vapour such as vapour of hydrocarbons may
be generated, or a portion of coal may be burnt so as to generate carbonic oxido
according to the well-known method for that purpose.
In operating with the constructions of apparatus above described I prefer to
supply the gas through a governor at uniform or nearly uniform pressure, and the
ingredients of the inflammable mixture may be compressed and introduced into the
cylinder at high pressure. In such a case oxygen may be employed instead of
common air in order to reduce the work of the compressing pumps and increase the
pressure and heat caused by the combustion.
In my former Provisional Specification, No. 3620, in the present year, I describe
a construction for preventing or reducing shock to the working parts of the engine
owing to the sudden rise of pressure consequent on the ignition of the inflammable
mixture.
ป
The following is another construction for the same purpose which I employ:-
The piston is connected at each end with a series of trunks, each working in a
cylinder. These trunks do not work quite tight in their cylinders, but the space
between them and their respective cylinders is so small that a gas flame cannot pass
through it.
The inflammable mixture is introduced in the annular space of the main cylinder
behind the piston, und in each cylinder behind its trunk or smaller piston, the
admission is governed by one valve and cut-off simultaneously.
The inflammable mixture in the annular space in the main cylinder is ignited just
before the first trunk clears it cylinder. As soon as this happens the inflammable
mixture behind that trunk is ignited, at which time the second trunk is not quite
clear of its cylinder. And thus the ignition of the mixture takes place in successive
portions, not all at once.
It is evident that the portions of the inflammable mixture might if desired be
lighted in the inverse order.
The following is another construction for the same purpose, applicable when steam
is used along with products of combustion:-A trunk is attached to each end of the
piston working in a cylinder. The inflammable mixture is introduced in the small
cylinder behind the trunk. At the same time steam enters the main cylinder in the
annular space behind the main piston. It is wire-drawn in entering so that
the space with steam at the atmospheric pressure, or nearly so.
fills
The inflammable mixture is ignited in the cylinder behind the trunk, and
simultaneously or shortly afterwards the steam is admitted into the cylinder at full
pressure. Thus the sudden pressure produced by the ignition of the inflammable
mixture acts on the trunk, not on the whole piston. The two plans of construction
may be combined.
In engines constructed as above described it is desirable in order to realize the
benefit of the construction that a great range of expansion should be used, in which

page_text: case there is great variation of pressure on the piston. In order to remedy incon-
venience from this cause numerous cylinders may be combined so as to equalize the
action of the engine, as is sometimes done in steam engines.
Figure 1 is a horizontal section; Figure 2 is an elevation partly in section; and
Figure 3 is a transverse section showing a construction of apparatus for carrying
out my Invention.
A, A, is the hot cylinder fitted at the extremities with valve apparatus and
passages G1, G2, for the introduction and ignition of the inflammable mixture. I have
represented these as having the construction used in Otto and Langen's engine.
B, B, is the cool cylinder in which the working fluid finishes its expansion. Pland
P are the pistons that work in the hot and cool cylinders respectively. Pl, the
piston in the hot cylinder, may be fitted with a shield, but this is not represented in
the Drawing. C, C, is a boiler the water in which surrounds a portion of the hot
cylinder A, A. This boiler communicates with the vessel H. within which is the
body (or plunger) N, which by its partial revolution causes the level of the water
to be raised or lowered at pleasure. M is an independent boiler in which steam is
raised previous to starting the engine, which may be heated by a gas flame or by
any mode of heating desired. A smaller flame may also act upon or within the
flues of this boiler to maintain heat and pressure of steam when the engine is not.at
work. D is the steam chest communicating with the vessel H and receiving thence
the steam generated in the boiler C, C. From this chest the steam passes to the cool
cylinder A, A, as governed by the valve V¹. E is the chest which receives the
elastic fluid which has performed work in the hot cylinder A, A.
From this chest
it passes to the cool cylinder B, B, as governed by the valve V2; fis the passage
through which this fluid passes from the cylinder A, A, to the chest E; i is the
passage by which the exhaust fluid passes from the cylinder B, B, to the refrigerator,
or if this is not used to the atmosphere. K, K, is the refrigerator which
sented as fitted with tubes, but any known method of cooling may be employed in
it, such for instance as cooling by direct contact with water.
repre-
Condensed water is extracted from the refrigerator by a pump which it has not
been thought necessary to show in the Drawing. Lis the wheel of a rotary pump
worked by the engine as shown, which extracts air or elastic fluid from the
refrigerator. Other known forms of pump may be employed.
The operations take place as follows:-Suppose that the piston P¹ is at the end
of its cylinder nearest x, the piston P2 is at the end of its cylinder nearest y. G¹, the
valve for admitting the inflammable mixture behind the piston P¹ is open. The slides
V and V2 open a communication between the end of the hot cylinder A, A, nearest y,
and the end of the cool cylinder B, B, nearest y. The end of the cylinder B, B,
nearest to x is open to the exhaust; the other valves are shut. The piston P¹
commences to move in the direction from a toy while the inflammable mixture enters
behind it. In front of it elastic fluid passes from the cylinder A, A, into the
cylinder B, B. The piston P2 moves in the direction from y to x, and elastic fluid
in front of it passes to the exhaust.
x
When the piston P¹ has advanced to a certain distance the valve G¹ is closed and
the inflammable mixture ignited, whereupon rise of pressure takes place. Simulta-
neously, or nearly so, the valve V₁ opens the communication between the cylinder
A, A, and the boiler. Steam enters the cylinder through the passage o, o, and
mixes with the hot products of combustion. Shortly afterwards the communication
with the boiler is closed. The mixed fluid expands and propels the piston, while at
the same time it imparts heat to the water in the boiler C through the sides of the
cylinder, thus generating steam which is subsequently used in the cylinder. The two
pistons P¹ and P2 reach the end of their strokes simultaneously. The communication
by which the fluid was passing from the end of the hot cylinder nearest y to the
end of the cool cylinder nearest y is now closed, and communication between the
other ends of the two cylinders is opened. Also the communication which was open
between the end of the cool cylinder nearest x and the exhaust is closed, and that

page_text: between the other end of the cool cylinder and the exhaust is opened. The valve G³
is opened to admit the inflammable mixture. The series of operations is then ready
to be repeated for the return stroke.
When a refrigerator maintained at low pressure is used, as shown in the Figures,
the exhaust passes into it and is extracted by the pump; but if no refrigerator is
used the exhaust is discharged into the atmosphere.
When the steam is generated by an independent source of heat the construction
shown admits of simplification. The boiler C, C, is dispensed with, and the second
cylinder B, B, may also if desired be dispensed with, the exhaust in this case passing
from the cylinder A, A, either into the refrigerator or into the atmosphere.
Figure 4 is a longitudinal section showing a construction for preventing or
reducing shock on the piston. Here A, A, is the main cylinder in which the piston
P¹ works; T1 and T2 are trunks attached to the piston P¹, each of these trunks
working in a small cylinder which it nearly fits, so that a gas flame cannot pass
between the trunk and the cylinder in which it works.
The inflammable mixture is introduced into the spaces behind the pistons through
the passages shown to the right governed by the valve V.
The exhaust passes away by the passages shown to the left communicating with
the passage e governed by the valve which controls the exhaust. A separate passage
is provided for lighting the inflammable mixture behind the piston P¹. The flame
cannot pass from this to the space behind the trunk T¹, being prevented by the
trunk. Shortly afterwards the trunk T₁ clears its cylinder and the mixture behind
it is ignited by contact with the highly heated products already in the cylinder.
And soon afterward the trunk T clears its cylinder and the mixture behind it is
ignited. Or otherwise a separate flame and passage for lighting may be provided,
so as to ignite the mixture separately in each cylinder, and in this case the mixture
behind each trunk may be lighted before that trunk has cleared its cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Matthew Piers Watt Boulton in the Great Seal Patent Office on the
26th March 1877.
MATTHEW PIERS WATT BOULTON, of Tew Park, Oxfordshire, Esquire. "IMPROVE-
MENTS IN APPARATUS FOR THE PRODUCTION OF MOTIVE POWER JOINTLY BY THE
ELASTIC FORCE OF PRODUCTS OF COMBUSTION AND OF STEAM OR VAPOUR, PART
OF WHICH IS APPLICABLE WHEN THE FORMER ALONE IS USED."
This Invention has for its object improvements in apparatus for the production
of motive power jointly by the elastic force of products of combustion and of steam
or vapour, part of which is applicable when the former alone is used.
In one form of apparatus constructed according to this Invention the steam or
vapour employed is generated by the heat of the products of combustion while
performing work. In this case I operate with more than one cylinder. In the
following description I shall suppose two cylinders to be employed and steam to be
the vapour made use of. One of the cylinders has a higher and one a lower tem-
perature. I shall speak of these as the hot and cool cylinders.
The hot cylinder is fitted at both ends with apparatus for the introduction and
ignition of the inflammable mixture, which apparatus may be of any known kind.
This cylinder, or a portion of it, is surrounded by water, which is contained within
a boiler. Passages are provided by which the steam space of this boiler communi-
cates with both ends of the cylinder, so that steam from the boiler enters either end
of the cylinder at the proper time.
The heated elastic fluid working in the hot cylinder imparts heat to the water
in the boiler and generates the steam, which afterwards is used in the cylinders,

page_text: I prefer that this steam should be generated at a pressure equal to the highest
pressure produced in the hot cylinder by the combustion of the inflammable
mixture.
The cool cylinder is connected with the hot cylinder in the same way in which
the low-pressure cylinder of a steam engine is connected with the high-pressure
one, so that the elastic fluid which has expanded to a certain degree in the hot
cylinder passes thence into the cool cylinder, and there finishes its expansion.
The operations are as follows:-The inflammable fluid mixture is introduced
behind the piston in the hot cylinder and is ignited, whereupon sudden rise of
pressure takes place. Simultaneously, or nearly so, a valve opens the communi-
cation between the hot cylinder and boiler, and steam enters from the boiler and
mixes with the hot products of combustion. After a certain determinate quantity
of steam has entered the cylinder its admission is cut off. When the piston
advances to a certain point the hot working fluid enters that portion of the
cylinder which is surrounded by the water of the boiler, and in passing through
this portion it imparts heat to the water in the boiler through the metal of the
cylinder and generates steam, which rises to the steam space of the boiler. While
the piston is thus urged behind by the heated mixture of products of combustion
and steam it drives out in front of it heated fluid which has performed work in the
second or cool cylinder, in which it continues to expand and performs further work.
The piston having reached the end of its stroke the valve through which the
elastic fluid was passing into the cool cylinder is closed, and a valve opens com-
munication between the elastic fluid which has just propelled the piston and the
cool cylinder. The same operations are then repeated for the return stroke.
The fluid which acts in the cool cylinder is discharged at the end of each
stroke either into the air or into a refrigerator maintained at low pressure, from
which it is extracted by a pump. When such a refrigerator is used it is provided
with a chamber for collecting water of condensation, which is removed by a small
pump.
The quantity of steam introduced into the cylinder is adjusted by means of a
regulator similar to that which I have described in a former Specification, by means
of which the area of the passage which supplies steam to the cylinder is increased
or diminished at pleasure.
Generally not more steam should be introduced than is necessary in order to
render the final temperature of the exhaust as low as is desired. More than one
hot cylinder may be provided in connection with one cool cylinder.
The piston rod and piston of the hot cylinder may be cooled by water com-
municating with the water in the boiler and assisting to heat it. I bave in a
previous Specification described constructions for this purpose. A small portion of
water may be introduced into the hot cylinder through the piston or piston rod,
serving to generate a portion of the steam used.
The construction may be modified by introducing the steam generated in the
space which surrounds the hot cylinder into the second cylinder. In this case a
hotter fluid acts in the hot cylinder for the generation of steam, but generally I
prefer the first construction in order that the steam may act at higher pressure.
Or again, the steam generated may be employed in a separate cylinder, or in any
node desired for the production of motive power.
In order to regulate the generation of steam I provide means for raising and
lowering the level of the water in the boiler by the motion of a body within it in
a manner explained by me in a former Specification, No. 1108, in the present year.
In this way a greater or a less portion of the surface of the cylinder is brought into
contact with the water of the boiler, as may be desired. The regulation may be
made self acting by means of any of the contrivances by which variations of
pressure are employed to cause motion of bodies.
Provision is made for applying independent heat to the water by means of an
auxiliary boiler, so that steam can be got up before the engine is started, and so
that when the engine is not at work the steam pressure can be maintained.

page_text: The admission of steam from the boiler into the cylinder may be made use of to
start the engine.
In another form of apparatus constructed according to this Invention the steam
employed is generated in a boiler not heated by the products of combustion which
perform work but by an independent source of heat. The cylinder in which this
steam works is fitted at either end with valve apparatus for the introduction and
ignition of the inflammable mixture. At the commencement of each stroke the
inflammable mixture is introduced into the cylinder and ignited. Simultaneously,
or almost so, the steam.enters from the boiler and mixes with the hot products of
combustion, and the mixed fluid performs work in the cylinder.
The admixture of the hot products of combustion superheats the steam, and
enables it to expand without condensation.
The mixed fluid may be treated like the steam of a steam engine. It may either
pass to a condenser or refrigerator at low pressure or be discharged into the air.
In this construction, as in the preceding one, a regulator may be used in order to
adjust accurately the quantity of steam admitted.
One cylinder may be employed in this construction, the whole expansion of the
fluid taking place in this. But successive cylinders for expansion, as are frequently
used in steam engines, may be employed if desired.
When apparatus of this kind is used the steam may be generated by coal or
other fuel in the ordinary way, while as an ingredient of the inflammable mixture
coal gas may be used, or inflammable vapour, such as vapour of hydrocarbons may
be generated, or a portion of coal may be burnt, so as to generate carbonic oxide
according to the well-known method for that purpose.
In operating with the constructions of apparatus above described I prefer to
supply the gas through a governor at uniform, or nearly uniform pressure, and the
ingredients of the inflammable mixture may be compressed and introduced into the
cylinder at high pressure. In such a case oxygen may be employed instead of
common air in order to reduce the work of the compressing pumps and increase the
pressure and heat caused by the combustion.
In my former Provisional Specification, No. 3620, in the present year, I described
a construction for preventing or reducing shock to the working parts of the engine
owing to the sudden rise of pressure consequent on the ignition of the inflammable
mixture.
The following is another construction for the same purpose which employ,―the
piston is connected at each end with a series of trunks, each working in a cylinder.
These trunks do not work quite tight in their cylinders, but the space between
them and their respective cylinders is so small that a gas flame cannot pass
through it.
The inflammable mixture is introduced in the annular space of the main cylinder
behind the piston, and in each cylinder behind its trunk or smaller piston, the
admission is governed by one valve, and cut off simultaneously.
The inflammable mixture in the annular space in the main cylinder is ignited
just before the first trunk clears its cylinder. As soon as this happens the inflam-
inable mixture behind that trunk is ignited, at which time the second trunk is not
quite clear of its cylinder, and thus the ignition of the mixture takes place in
successive portions, not all at once.
It is evident that the portions of the inflammable mixture might, if desired, be
lighted in the inverse order.
The following is another construction for the same purpose applicable when
steam is used along with the products of combustion. A trunk is attached to each
end of the piston working in a cylinder. The inflammable mixture is introduced
in the small cylinder behind the trunk. At the same time steam enters the main
cylinder in the annular space behind the main piston. It is wire drawn in entering
so that it fills the space with steam at the atmospheric pressure or nearly so.
The inflammable mixture is ignited in the cylinder behind the trunk, and

page_text: simultaneously or shortly afterwards the steam is admitted into the cylinder at full
pressure. Thus the sudden pressure produced by the ignition of the inflammable
mixture acts on the trunk, not on the whole piston. The two plans of construction
may be combined.
In engines constructed as above described it is desirable in order to realize the
benefit of the construction that a great range of expansion should be used, in which
case there is great variation of pressure on the piston. In order to remedy incon-
venience from this cause numerous cylinders may be combined so as to equalize the
action of the engine as is sometimes done in steam engines.
Figure 1 is a horizontal section; Figure 2 is an elevation, partly in section; and
Figure 3 is a tranverse section showing a construction of apparatus for carrying out
my Invention.
A, A, is the hot cylinder fitted at the extremities with valve apparatus
and passages G₁, G³, for the introduction and ignition of the inflammable
mixture. I have represented these as having the construction used in Otto and
Langen's engine. B, B, is the cool cylinder, in which the working fluid finishes its
expansion. P1 and P2 are the pistons that work in the hot and cool cylinders
respectively. P¹, the piston in the hot cylinder, may be fitted with a shield, but
this is not represented in the Drawing. C, C, is a boiler, the water in which
surrounds a portion of the hot cylinder A, A. This boiler communicates with the
vessel H, within which is the body (or plunger) N, which, by its partial revolution,
causes the level of the water to be raised or lowered at pleasure. M is an
independent boiler in which steam is raised previous to starting the engine which
may be heated by a gas flame or by any mode of heating desired. A smaller flame
may also act upon or within the flues of this boiler to maintain heat and pressure
of steam when the engine is not at work. D is the steam chest communicating
with the vessel H, and receiving thence the steam generated in the boiler C, C.
From this chest the steam passes to the cylinder A, A, as governed by the valve V¹.
E is the chest which receives the elastic fluid which has performed work in the hot
cylinder A, A; from this chest it passes to the cool cylinder B, B, as governed by
the valve V. f is the passage through which this fluid passes from the cylinder
A, A, to the chest E. i is the passage by which the exhaust fluid passes from the
cylinder B, B, to the refrigerator, or if this is not used to the atmosphere. K, K, is
the refrigerator which is represented as fitted with tubes, but any known method
of cooling may be employed in it, such, for instance, as cooling by direct contact
with water.
Condensed water is extracted from the refrigerator by a pump which it has not
been thought necessary to show in the Drawing. L is the wheel of a rotary pump
worked by the engine, as shown, which extracts air or elastic fluid from the
refrigerator. Other known forms of pump may be employed.
The operations take place as follows,-Suppose that the piston P¹ is at the end
of its cylinder nearest & the piston P is at the end of its cylinder nearest y. G¹
the valve for admitting the inflammable mixture behind the piston P¹ is open. The
slides V and V2 open the communication between the end of the hot cylinder
A, A, nearest y and the end of the cool cylinder B, B, nearest y. The end of the
cylinder B, B, nearest to x is open to the exhaust; the other valves are shut. The
piston P¹ commences to move in the direction from x to y, while the inflammable
mixture enters behind it. In front of it elastic fluid passes from the cylinder A, A,
into the cylinder B, B. The piston P2 moves in the direction from У
to x,
and
elastic fluid in front of it passes to the exhaust.
When the piston P¹ has advanced to a certain distance the valve G¹ is closed and
the inflammable mixture ignited, whereupon rise of pressure takes place. Simul-
taneously or nearly so the valve V₁ opens the communication between the cylinder
A, A, and the boiler; steam enters the cylinder through the passage o, o, and mixes
with the hot products of combustion; shortly afterwards the communication with
the boiler is closed. The mixed fluid expands and propels the piston, while at the

page_text: same time it imparts heat to the water in the boiler C through the sides of the
cylinder, thus generating steam which is subsequently used in the cylinder. The
two pistons P¹ and P2 reach the end of their strokes simultaneously. The com-
munication by which the fluid was passing from the end of the hot cylinder
nearest y to the end of the cool cylinder nearest y is now closed, and communication
between the other ends of the two cylinders is opened. Also the communication
which was open between the end of the cool cylinder nearest x and the exhaust is
closed, and that between the other end of the cool cylinder and the exhaust is
opened. The valve G2 is opened to admit the inflammable mixture. The series of
operations is then ready to be repeated for the return stroke.
When a refrigerator inaintained at low pressure is used as shown in the Figures
the exhaust passes into it and is extracted by the pump, but if no refrigerator
used the exhaust is discharged into the atmosphere.
When the steam is generated by an independent source of heat the construction
shown admits of simplification. The boiler C, C, is dispensed with, and the second
cylinder B, B, may also, if desired, be dispensed with; the exhaust in this case
passing from the cylinder A, A, either into the refrigerator or into the atmosphere.
Figure 4 is a longitudinal section showing a construction for preventing or
reducing shock on the piston. Here A, A, is the main cylinder in which the
piston P¹ works; T¹ and T are trunks attached to the piston P¹, each of these
trunks working in a small cylinder which it nearly fits, so that a gas flame cannot
pass between the trunk and the cylinder in which it works.
The inflammable mixture is introduced into the spaces behind the pistons through
the passages shown to the right governed by the valve V.
The exhaust passes away by the passages shown to the left, communicating with
the passage e, governed by the valve which controls the exhaust. A separate
passage is provided for lighting the inflammable mixture behind the piston P¹.
The flame cannot pass from this to the space behind the trunk T¹, being prevented
by the trunk. Shortly afterwards the trunk T¹ clears its cylinder, and the mixture
behind it is ignited by contact with the highly heated products already in the
cylinder, and soon afterwards the trunk T2 clears its cylinder, and the mixture
behind it is ignited, or otherwise a separate flame and passage for lighting may be
provided so as to ignite the mixture separately in each cylinder, and in this case
the mixture behind each trunk may be lighted before that trunk has cleared its
cylinder.
Having thus described the nature of my Invention and the manner of performing
the same, I will have it understood that I claim,―
First. The construction of apparatus for the production of motive power jointly
by the elastic force of products of combustion and steam or vapour in such manner
that combustion having taken place so as to generate elastic products at high
pressure which perform work on a piston in a cylinder, a portion of the heat
resulting from this combustion is imparted from the cylinder to a boiler, in which
it generates steam or vapour, subsequently used to perform work, and the elastic
fluid which has performed work in this cylinder passes from it into a second
cylinder, within which it further expands, performing additional work.
Second. The construction of apparatus in a similar manner with more than two
cylinders.
Third. The construction of the apparatus in such manner that the steam
generated performs work jointly with the products of combustion in one or more
of the cylinders.
Fourth. The construction of apparatus in such manner that steam or vapour.
generated in an independent boiler is admitted into a cylinder, within which a
piston is actuated by the rise of pressure produced by the ignition of gas or vapour
along with air or other suitable agent, so that the steam or vapour and the products
of combustion expand and perform work conjointly in the cylinder.
Fifth. The construction of piston with trunks so that the inflammable mixture

page_text: acting in the cylinder is ignited in successive portions in order that shock on the
piston may be prevented or reduced.
Sixth. The construction of engines worked jointly by the elastic force of
products of combustion and of steam or vapour substantially in the manner
described and illustrated by the annexed Drawings.
Ju witness whereof, I, the said Matthew Piers Watt Boulton, have hereunto
set my hand and seal, this Tenth day of March, in the year of our Lord
One thousand eight hundred and seventy-seven.
ПАТТЕMАЯ
M..P. W. DOULTON. (L.S.)