Year: 1887

page_text: Date of Application, 21st July, 1887
Complete Left, 21st Apr., 1888
Complete Accepted, 25th May, 1888
We H. C. BULL & COMPANY, Limited and HENRY CLAY BULL, Engineer both of
31 Poultry, London do hereby declare the nature of the said invention to be as
follows:-
This Invention has for its object the production of power with the smallest quantity
of fuel, such fuel being used in a gaseous state.
According to this Invention gas is burned, or exploded, in one end of a cylinder
of an engine and at the other end of the cylinder steam is used, and it is also
proposed to use compressed air in combination with the steam. The air is previously
superheated and both air and steam are used expansively.
gas
The explosive end of the cylinder is. fitted with an inner piston which derives its
movement from a cam, or equivalent device on the main shaft. The purpose of this
piston is to remove the products of combustion and draw in a fresh charge of and
air during a portion of the return stroke. This charge of gas and air is preferably
compressed previously to explosion during the remainder of the return stroke. It.
will be seen that by this arrangement the cylinder is only partly filled with an
explosive mixture and that the explosive gases are worked to a greater degree of
expansion thereby reducing their pressure and temperature at the exhaust by which
a greater amount of work out of the explosive gases is obtained. This is an
important feature in the economy of fuel in motors using explosive mixtures of gas
and air. It will be seen that by this arrangement an explosion is obtained at every
revolution of the engine. The inner piston, is not quite so large as the cylinder and
begins its return stroke which is effected by the cam before mentioned a little before
the main piston reaches it, and it reaches the base of the cylinder at the same time
as the main piston reaches the end of the return stroke. The gas and air which has
previously been drawn in finds its way to the front of the inner piston through the
space intervening between this piston and the cylinder. The jacket surrounding the
cylinder is kept full of water at a temperature equivalent to a desired steam pressure
and this water is drawn from and returned to a steam generator hereinafter described.
By jacketting the cylinder with hot water in place of cold there will be less loss of

page_text: heat from the exploded gases and therefore a fuller pressure diagram and a greater
amount of power will be obtained from each explosion. This is the point of economy
of this motor.
A suitable valve placed near the centre of the cylinder and arranged to open and
remain open during a portion of the return stroke and until the two pistons nearly
touch each other, thus allowing the products of combustion to escape from between
the two pistons as they advance towards each other.
A suitable steam generator and steam and air superheater and a suitable air pump
is part of the motor. A portion of the steam necessary to work the front end of the
cylinder is produced by the heat absorbed in the jacket. Another portion as well as
the superheating of steam and air which are mixed together is obtained from the
exhaust gases from the explosive end of the motor cylinder. The steam end of
the motor is provided with suitable valves preferably piston valves arranged to cut
off at any desired part of the stroke such as half stroke. In engines of the explosive
type it is very essential to have a self starter which is usually a chamber wherein a
charge of air may be compressed by an air pump before the engine is stopped and
held in reserve to restart the engine when required.
According to our Invention the steam space of the generator and the space of the
superheater are used for the purpose of this reservoir.
Suitable means are provided for igniting the charge of gas and air after they have
been compressed.
1

page_text: H. C. BULL AND COMPANY Limited and HENRY CLAY BULL, Engineer, both of
31 Poultry London, do hereby declare the nature of the said invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
This Invention relates to motors in which power is produced from fuel used in a
gaseous, or vapourous, or comminuted state within a working cylinder, or in a
combustion chamber connected with such cylinder, and has for its object to obtain
from the fuel used, a larger per centage of available heat produced by the combustion
of it, and to so render engines of this type more efficient than heretofore.
According to this Invention gas is burned or exploded in one end of a cylinder of
an engine, and at the other end of the cylinder steain is used, and it is also proposed
to used compressed air in combination with the steam. The air is previously super-
heated and both air and steam are used expansively.
The explosive end of the cylinder is fitted with an inner or supplementary piston
which derives its movement from a cam or equivalent device on the main shaft. The
purpose of this piston is to remove the products of combustion and to draw in a fresh
charge of gas and air during a portion of the return stroke of the main piston. This
charge of gas and air is preferably compressed previously to explosion during the
remainder of the return stroke. It will be seen that by this arrangement the cylinder
is only partly filled with an explosive mixture, and that the explosive gases ure
worked to a greater degree of expansion, thereby reducing their pressure and
temperature at the exhaust, by which a greater amount of work out of the explosive
gases is obtained. This is an important feature in the economy of fuel in motors
using explosive mixtures of gas or vapour and air. It will also be observed that by
this arrangement an explosion may be obtained at every revolution of the engine. The
inner piston is not quite so large as the cylinder and begins its return stroke-which
is effected by the cam before mentioned a little before the main piston reaches it,
and reaches the base of the cylinder at the same time as the main piston reaches the
end of the return stroke, the gas and air which has previously been drawn in finds its
way to the front of the inner piston through the space intervening between this piston
and the cylinder.
The jacket surrounding the cylinder is kept full of water at a temperature
equivalent to a desired steam pressure, and this water is drawn from and returned to a
steam generator hereinafter described. By jacketing the cylinder with hot water in
place of cool, there will be less loss of heat from the exploded gases and therefore a
fuller pressure diagram, and a greater amount of power will be obtained from each
explosion. This is also a point of economy of this motor.
A suitable valve placed near the centre of the cylinder and arranged to open and
remain open during a portion of the return stroke, and until the two pistons nearly

page_text: Figure 1 is an end sectional elevation of the motor.
Figure 2 is a front sectional elevation of the same.
Figure 3 is a full end elevation of the motor and,
Figures 4 and 5 are respectively a full plan of same and a cross section at X X
Figure 1.
In the Drawings like letters are used to denote the same, or like parts throughout
the views.
With reference to the Drawings A, is the cylinder, having in it, the hollow working
piston B and a second piston C and surrounded by the water jacket or space a ; D is
the cross head of hollow formation and provided with a plunger a, non return valve a¹
and circulating tube a³; b, are hollow piston rods connecting the piston B and cross-
head D, which is provided with a diaphragm d; H is a slide valve controlling the
exhaust of the products of combustion and steam admission and exit, and is provided
with ports n and m for the gaseous products and steam and air; J, is the ignition
valve of any suitable type, and R designates the air and gas admission device which
also may be of any known suitable kind.
With special reference to Figure 3, L represents the steam generator which consists
of a number of vessels provided internally with tubes of any suitable known kind,
through which the products of combustion from the cylinder A are passed;
p, designates the gaseous products exhaust pipe arranged within the steam and air
supply pipe o a, is a water pipe forming communication between the steam
generator L and the water casing a, and a is a non return valve therein.
E represents the crank having a groove e for operating the piston C; c² is a rod
connected to the piston rod c¹ of the piston C and is provided with a roller which
works in the said groove e. f¹ is an eccentric for operating the controlling valve of
the air pump F and is an eccentric which operates the valves H and J through
the rod is the air pump rod and is connected to and worked from the
It will be seen that the cylinder A is mounted upon columns G, which are
secured to the entablature of the motor. To two of these columns the air pump F
is secured and they also serve as slides to the crosshead D. The air pump F may
crosshead D.

page_text: be of any known approved type and forces air into the steam space of the
generator I, the water level in which is marked W L. It may here be stated
that the exhaust gaseous products leave the cylinder by the ports K and K¹, the
latter of which leads round the cylinder in the ordinary manner, and opens into
the pipe p, whilst the steam passes by the annular passage formed by the pipe O
and the pipe p into a port-not shown in the Drawings-which leads round the
cylinder from the point where the pipe O is connected to it, and opens out into
the casing I, from whence it is led by the port to the cylinder. is the steam
and air exhaust port, by which when the port m of the valve H bridges it and
the port 1, the steam and air escapes from the cylinder A in the usual way.
The above description with reference to the Drawings sets forth the general
arrangement and combination of the various parts of the inotor. It will be observed
that these individual parts are all known mechanisms or devices, and therefore no
further detailed description, or drawings of them are necessary. We will therefore
now proceed to describe the operations and functions of the various parts in whole
and in detail.
The combustible mixture of gas and air in proper proportions is introduced into
the cylinder A behind the piston C through a port, leading from the gas and air
admission device R, by the downward travel of the piston C, the stroke of which is
actuated and controlled by the groove e of the crank E, the rod and piston rod c¹.
The said groove is so constructed and arranged as to bring the downward limit of
travel of the piston C just above the exhaust ports K; consequently the volume of
the gas and air charge introduced by the travel of this piston will be approximately
equal to half the capacity of the cylinder. During the downward travel of the
piston C, the main, or working piston B will have travelled a portion of its upward
stroke, say to a point just below the ports K. By the cooperation of these two
pistons, the products of combustion-which previous to the commencement of the
strokes of these pistons would have existed between them would be expelled through
the exhaust, port K into the port K', passing thereto by the valve port n. From the
port K the products are conducted by an extension of the port K' (not shown in the
Drawings) to the pipe p, which lies concentrically within the pipe o. From this pipe
they are led through the steam generator L.
a
The combustible mixture introduced into the cylinders as just described, by the
piston C, is now compressed into a space forming a combustion chamber in the upper
part of the cylinder, in the ordinary way, by the further upward travel of the working
piston B; the piston Calso travelling upwards concommittently with the working
piston, but in advance of it; both pistons will arrive at the end of their respective
upward strokes in the position shown in Figures 1 and 2. The piston C being of
slightly smaller diameter than the cylinder A allows the combustible mixture to flow
in an annular stream at its periphery, from the upper to the under side thereof. The
ignition of the charge is effected in the ordinary way when in its compressed state by
kindling valve J above specified, and the working piston B is pressed forward by
the dilation of the ignited charge to the end of its outward stroke; the piston C
remaining stationary throughout the stroke. It must be here mentioned that the
valve H and the exhaust ports K K¹, and steam and air ports and are so
constructed, arranged and operate that the various passages will be open and closed
at the required moments as will be understood. For instance the exhaust port K
will be closed by the lap of the valve H during the whole down and steam expelling
stroke of the working piston B, and the latter half of its upper stroke, and only open
during the first part of its upward stroke and the downward stroke of the piston C;
also the steam and air port will only be open to the steam chest I during a certain
portion of the upward stroke of the working piston B, (thereby using the steam and
air expansively) but open to the exhaust port 1, through the port m of. the valve,
during the whole or nearly the whole of the downward stroke of such piston. By
the above it will be evident that the downward stroke of the working piston B is
caused by the pressure due to the heat of combustion of the gases behind it, and that
in this stroke it expels the used steam and air from the cylinder in front of it; the

page_text: piston C during this time remaining stationary at the top of the combustion space of
the cylinder A; and further that the upward stroke of the piston B is caused by the
pressure of steam and air beneath it (admitted as described) and in the first half of
such stroke together with the concommitant action of the piston C expels the
products of combustion from the cylinder; the latter portion of the stroke being used
to compress the combustible mixture above it, such mixture having been introduced
into the cylinder by the piston C as above described.
It has herein been stated that the waste products of combustion are used to
generate the steam used in the cylinder of the engine, but for this a great portion
of the heat is obtained from the escape of the heat of combustion of the charge
through the walls of the cylinder into the water surrounding it. The water used
in the jacket a is pumped from the steam generator L by the pump a², and
circulated through the jacket a of the cylinder and cylinder cover and piston B.
To attain this result the cylinder and cylinder cover jacket a are provided with a
diaphragm.
In operation water under pressure is drawn from the generator L through the
pipe a and non return valve at by the outward stroke of the pump a² into one half of
the jackets, and it is forced under pressure upon the return stroke of the pump
through the valve a¹, into the crosshead D, up the right hand pipe b, through the
piston B, and down the other pipe b, back into the crosshead D, from whence it
passes by the pipe a³, into the other half of the jackets a. From here it is led back
by a suitable pipe to the steam generator L.
It is known that when air is mixed with steam and used in a non condensing
steam engine, that economical results will follow. To obtain these results in con-
nection with the motor herein described, we utilize this fact, and force air into
the space of the steam generator L₁, by the pump F. Any kind of pump may be used
for the purpose. The air becomes heated when inixed with the steain and the mixture
passes from the steam space of the generator L by the annular passage between the
pipes p and o into the valve chest I, and is admitted to the cylinder, and operates as
herein before described. The mouth of the pipe o is designated o¹ and the air and
steam enter it there.
It has been above stated that to start the engine compressed air is used. This air
we obtain from the steam space of the steam generator into which air is compressed
by the pump F, whenever steam is about to be "lowered." Hence when it is
required to use the engine (when steam is not "up") the air previously compressed
in the steam space is admitted to the steam chest I by a suitable valve or cock, (not
shown in the Drawings) and starts it. As soon as sufficient momentum is obtained,
the gas and air are admitted and ignited in the manner above specified. The cock
may then be closed; the action of the engine having become continuous.
Having now particularly described and ascertained the nature of the said Inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :
First. In engines of the type herein specified, the mode herein described of
operating such engines, which mode consists in effecting one stroke of such engines
by pressure due to the heat of combustion of a mixture of gas, or vapour and air, and
effecting the return stroke of the engine by steam generated by the exhaust and other
escaping heat of the gases of combustion, substantially as set forth.
Second. In a combined gas and steam motor, the method herein described of
utilizing the heat passing, or escaping from the walls, or sides of the cylinder subjected
to the heat of combustion of the gas, or vapour, and air, which method consists in
causing the water used for generating the steam to be employed in such engine to
pass, or be circulated around the said walls of the cylinder either at atmospheric
pressure, or at the pressure of the steam in the generator, as, or substantially as set
forth.
Third. In engines of the type herein specified the method herein described of
operating such engines, which method consists in effecting one stroke of such engine
.

page_text: by pressure due to the heat of combustion of a mixture of gas, or vapour and air,
utilizing the heat escaping from the walls, and with the exhaust gases of combustion
to generate steam, forcing into the steam so made a proportion of atmospheric air,
and utilizing such steam so produced and the air to effect the return stroke of the
engine, as, or substantially as set forth.
Fourth. Introducing the air, or gas or vapour into cylinders of engines of the type
herein specified and expelling the products of combustion by a secondary piston C
working in connection with the said main or working piston as described, whereby a
volume of air and gas or vapour, of a half, or about a half a cylinder capacity,
is introduced into the cylinder, and approximately the whole of the exhaust products
of combustion are expelled, substantially as and for the purposes set forth.
Fifth. The herein described method of heating and circulating water employed in
combined gas and steam engines, which method consists in drawing the water from
the steam generator by a pump-having inlet and outlet valves-and worked by the
cross head of the engine, into one half of a jacket surrounding the cylinder and covers,
and forcing such water through hollow piston rods, and the piston into the other half
of the cylinder jacket and covers, and then back to the steam generator, as, or
substantially as set forth.
Sixth. In an engine operated by pressure due to the heat of combustion the
combination of a working cylinder A, the piston of which is operated alternately by
gas, or vapour and air, and steam and air, and air pump and a steam generator, the said
air pump, cylinder and steam generator being connected by ducts and operating as
described; all as, or substantially as set forth.
Seventh. In combined gas and steam engines of the type herein described, a valve
such as Hadapted to control the admission and emmission of steam, or steam and air
to and from the cylinder thereof, and the exhaust gaseous products of combustion
therefrom, as, or substantially as set forth.
Eighth. The engine and steam generator L combined and connected by steam
pipe o, exhaust gaseous products pipe p, and water pipe a³, all arranged and operating
as set forth with reference to the Drawings.
1 1000
Dated this 20th day of April 1888.
H. C. BULL & COMPANY, LIMITED.
HENRY CLAY BULL.
By Cheesbrough & Royston, .
Agents.