Improvements in and connected with Internal Combustion "Heat" Engines.
Year: 1888

page_text: Date of Application, 11th Oct., 1888
Complete Specification Left, 11th July, 1889-Accepted, 11th Jan., 1890
PROVISIONAL SPECIFICATION.
Improvements in and connected with Internal Combustion "Heat"
Engines.
1 ERNEST RICHARD ROYSTON of 20 Fern Grove, Liverpool, in the County of
Lancaster, Engineer do hereby declare the nature of my said invention to be as
follows:-
This Invention relates mainly to those gas or vapour motor engines operated by
pressure due to the heat of combustion within the cylinder or combustion chamber
thereof of a combustible gas, vapour or comminuted combustible oil, in which the
products of combustion remaining in the cylinder at the termination of an effective
stroke are expelled from the cylinder by the introduction into the cylinder of a charge
of atmospheric air, or by a charge of atmospheric air in conjunction with the return
stroke of the piston; such engines are described in the Specification of my former
Patent No. 13623 of A.D. 1885, and also in the Specification of Patents No. 3010
A.D. 1886 and No. 888 A.D. 1887 granted respectively to George Frederick Deacon
and Harold Heron Hosack.
Gas engines provided with improvements according to my Invention consist and
are operated as follows:
In a single acting gas, vapour or oil engine, which is arranged to operate with one
effective stroke in four, the piston is, during its return stroke following the effective
stroke, arranged to expel a portion of the products of combustion remaining in the
cylinder, whilst, the other portion of the said products is removed from the cylinder
by the introduction into it of a charge of atmospheric air, the introduction being
caused or effected by putting the interior of the cylinder behind the piston in com-
munication with a chamber or space, the pressure within which is lower than that of the
atmosphere, and admitting atmospheric air to the cylinder; by which means, if the
pressure in the said partially evacuated chamber be sufficiently low and the capacity
thereof sufficiently large, the products of combustion will be replaced by air. This
chamber I term the vacuum chamber.
In a four cycle engine the front portion of the cylinder may be enclosed to form a
chamber as set forth in the said Specification of H. H. Hosack No. 888 A.D. 1886
-and the space traversed by the front of the piston; and the piston, used as a pump
to exhaust such chamber, or to exhaust a separate vacuum chamber.
In this type of engine either one or both of the inward strokes of the piston made
between each effective stroke may be used to exhaust the chamber. In the case of a
compound engine working upon this cycle of operations I construct such engine with
a differential cylinder and piston, so that the front portion of the cylinder and piston
is the larger, and into this portion the products of combustion at terminal pressure are
conducted from the initial or small cylinder. In such a case I use the annular space
formed behind the larger piston as the exhaust pump, and by which the aforesaid
vacuum chamber is exhausted. In double cylinder compound engines the vacuum
may be in a like or equivalent manner employed for the same purpose.
Instead of utilizing a cylinder or pump for exhausting the vacuum chamber it may
be exhausted by an ejector in which the exhaust gases serve as the motor fluid a non
return valve being placed upon the duct leading from the chamber to the ejector
inlet.
The air may either be admitted at the rear end of the cylinder and the remaining
products of combustion emitted by ports or a passage annularly arranged, or other-
wise in the cylinder, at a point near the inner end of the stroke of the piston, or at
any suitable point; or, it may be admitted at the side of the cylinder and emitted at
the room and

page_text: At the end of the effective stroke of the initial piston in the compound engine, com-
munication by a suitable valve is made between the initial cylinder and the front
portion of the large cylinder.. In the return stroke the gases act upon the area of the
large piston, press the piston backwards and when it has arrived at or near the inner
end of its stroke, the gases from both cylinders are freed and escape, and the afore-
said communication having been closed, communication is made with the annular
vacuum chamber, or with a separate vacuum chamber as above specified; by which
the remaining products of combustion in the initial cylinder are removed and
replaced by fresh atmospheric air. The next outward stroke of the larger piston is
used to expel the remaining products of combustion therein, and the next two strokes
may be used as part of a compound system in conjunction with a separate engine, or
for any other desired purpose; or they may be idle strokes.
The combustible gas used in the single or compound engine may be introduced at
ordinary pressure during the outstroke of the piston next after the expulsion of the
products of combustion, or it may be forced in by a separate gas pump at any desired
period or point of the stroke.
In the case of an engine wherein an effective stroke is obtained at every revolution
of the crank, the gases at terminal pressure at the end of the effective stroke are first
released and the exhaust valve closed; a communication is then made between the
interior of the cylinder behind the piston and the vacuum chamber, when the
remaining products of combustion are expelled by the introduction of air, which is
compressed by the return stroke of the piston, the combustible charge of gas being
introduced and mixed with such air by a suitable pump. In this case if the engine
be of the construction wherein a single cylinder and piston serve as a motor cylinder
and a pump, the piston may be arranged to expel a portion of the remaining products
of combustion by the first portion of its inward stroke, the residue being then expelled
by making the communication between the cylinder and the vacuum chamber, air
being thereby caused to force out the rest of the said products. In all cases suitable
automatically or mechanically operated valves or slides may be used to control ingress
or egress of the air and gases to and from the parts of the engine.
In all cases the examples of engines and the applications of improvements according
to my Invention above specified, some or all of the products as the case may be are
expelled by air which is introduced into the cylinder of the engine by putting that
cylinder in communication with the air and with a vacuum chamber; now instead of
employing a partial vacuum for this purpose I may use compressed air in connection
with my present improvements above specified, after the manner set forth in the
Specification of my aforesaid prior Patent No. 13623 A.D. 1885 and in the Specifica-
tions of the Patents of G. F. Deacon No. 3010 A.D. 1886 and H. H. Hosack No. 888
A.D. 1887 aforesaid, or in any modified manner thereof.
I would have it understood that the improvements herein described may be used in
any combination, or separately, and in various forms and in connection with different
types of air and gas or vapour engines.
Dated this 10th day of Octoba. 1900
CHEESBROUGH & ROYSTON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and connected with Internal Combustion
Engines.
<
Heat'
"
I, ERNEST RICHARD ROYSTON, of 20 Fern Grove, Liverpool, in the County of
Lancaster, Engineer, do hereby declare the nature of my 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, mainly, to those gas or vapour motor engines operated by
pressure due to the heat of combustible gas, vapour and comminuted combustible oil,
in which all or the greater portion of the products of combustion remaining in the

page_text: cylinder at the termination of an effective stroke are expelled from the cylinder
by the piston or by the introduction into the cylinder of a charge of atmospheric air,
or by a charge of atmospheric air in conjunction with the return stroke of the piston ;
such engines are described in the Specification of my former Patent No. 13623 of
A.D. 1885, and also in the Specification of Patent No. 3010 A.D. 1886 and No. 888
A.D. 1887 granted respectively to George Frederick Deacon and Harold Heron
Hosack.
Gas engines provided with improvements according to my present Invention consist
and are operated as follows:-
In a single acting air and gas, vapour, or oil engine, which is arranged to operate
with one effective stroke in four, the piston is, during its return stroke following the
effective stroke, arranged to expel a portion of the products of combustion remaining
in the cylinder, whilst, the other portion of the said products is removed from the
cylinder by the introduction into it of a charge of atmospheric air, the introduction
being caused or effected by putting the interior of the cylinder behind the piston in
communication with a chamber or space, the pressure within which is lower than
that of the atmosphere and admitting atmospheric air to the cylinder; by which
means, if the pressure in the said partially evacuated chamber be sufficiently low and the
capacity thereof sufficiently large, the products of combustion will be replaced by air.
This chamber I term the vacuum chamber.
In a four cycle engine the front portion of the cylinder may be enclosed to form a
chamber as set forth in the said Specification of H. H. Hosack No. 888 A.D. 1886
-and the space traversed by the front of the piston, and the piston used as a pump
to exhaust such chamber, or to exhaust a separate vacuum chamber.
In this type of engine either one or both of the inward strokes of the piston made
between each effective stroke may be used to exhaust the chamber.
In the case of a compound engine working upon this cycle of operations I construct
such engine with a differential cylinder and piston so that the front portion of the
cylinder and piston is the larger, and into this portion the products of combustion at
terminal pressure are conducted from the initial or small cylinder. In such a case I
use the annular space formed behind the larger piston as the exhaust pump and by
which the aforesaid vacuum chamber is exhausted. In double compound engines the
vacuum may be in a like or equivalent manner employed for the same purposes.
Instead of utilizing a cylinder or pump for exhausting the vacuum chamber it may
be exhausted by an ejector in which the exhaust gases serve as the motor fluid: a
non-return valve being placed upon the duct leading from the chamber to the ejector
inlet.
The air may either be admitted at the rear end of the cylinder and the remaining
products of combustion emitted by ports or a passage annularly arranged, or other-
wise in the cylinder, at a point near the inner end of the stroke of the piston, or at
any suitable point. Or, it may be admitted at the side of the cylinder and emitted at
the rear end.
At the end of the effective stroke of the initial piston, in the compound engine,
communication by a suitable valve is made between the initial cylinder and the front
portion of the large cylinder. In the return-stroke the gases act upon the area of the
large piston, press it backwards, and when it has arrived at or near the inner end of
its stroke, the gases from both cylinders are freed and escape, and the aforesaid com-
munication having been closed, communication is made with the annular chamber, or
with a separate vacuum chamber, as above specified, by which the remaining products
of combustion in the initial cylinder are removed and replaced by fresh atmospheric
air. The next outward stroke of the larger piston is used to expel the remaining
products of combustion therein, and the next two strokes may be used as part of a
compound system in conjunction with a separate engine, or for any other desired
purpose, or they may be idle strokes.
The combustible gas or other fluid used in the single or compound engine may be
introduced at ordinary pressure during the outstroke of the piston next after the

page_text: expulsion of the products of combustion,. or it may be forced in.by a separate gas
pump at any desired period or point of the stroke.
In the case of an engine wherein an effective stroke is obtained at every revolution
of the crank, the gases at terminal pressure at the end of the effective stroke are first
released and the exhaust valve closed; a communication is then made between the
interior of the cylinder behind the piston and the vacuum chamber, when. the
remaining products of combustion are expelled by the introduction of air, which is
compressed by the return stroke of the piston, the combustible charge of gas being
introduced and mixed with such air by a suitable pump. In this latter case, if the
engine be of the construction wherein a single cylinder and piston serve as a motor
cylinder and a pump, the piston may be arranged to expel a portion of the remaining
products of combustion by the first portion of its inward stroke, the residue being
then expelled by making the communication between the cylinder and the vacuum
chamber being thereby caused to force out the rest of the said products. In all cases
suitable automatically or mechanically operated valves or slides may be used to
control the ingress and egress of the air and gases to and from the parts of the
engine.
-
In all cases the examples of engines and the applications of improvements according
to my Invention above specified, some or all of the products as the case may be are
expelled by air which is introduced into the cylinder of the engines by putting that
cylinder in communication with the air and with a vacuum chamber; now instead of
employing a partial vacuum for the purpose I may use compressed air in connection
with my present improvements above specified, after the manner set forth in the
Specification of my aforesaid prior Patent No. 13623 A.D. 1885 and in the Specifi-
cations of the Patents of G. F. Deacon No. 3010 A.D. 1886 and H. H. Hossack
No. SS8 A.D. 1887. aforesaid or in any modified manner thereof.
.
Having thus stated generally the nature of this invention I will now describe it
with reference to the drawings hereto annexed which illustrate several examples of
air and gas or petroleum engines involving improvements according to this
Invention.
The following comprise the chief letters of reference used in the description of the
drawings to designate the chief parts of the engines; the same letters being employed
throughout the various views to denote. the same or like parts:
a is the cylinder of the engine in which the combustion of gases or vapours takes
place..
a designates the combustion chamber of the cylinder a, and is coned or tapered ;
b represents the larger or low pressure cylinder, in the case of compound engines;
c designates the chamber adapted to serve either as a vacuum chamber,--or a low
pressure compressed air reservoir;
distan annular port encircling the cylinder a and communicating therewith by
apertures, or an annular slot or opening;
e is the piston of the engine, (in the case of compound engines of the high pressure
cylinder) having a coned end e¹ for guiding or distributing air;
.
fis the piston of the low pressure cylinder of the compound engines;
g designates a valve through which air is introduced into, or passed out of the com-
bustion chamber a¹;
h is a valve controlling communication between the annular port d and the
chamber c;
i is an ordinary automatically operating lift or non-return valve controlling the
inlet to the portion of the cylinders of the engines which are used as an air or vacuum
pump; and
jis an outlet valve of same type for same.
A is a mechanically operated exhaust valve of any suitable known type.
Figure 1 illustrates an engine in sectional elevation according to the invention
in which an effective stroke in four, for one side of the piston, is obtained.
The action of the engine is, that, in the effective stroke, the piston is pressed

page_text: :
forward in the usual manner by the pressure due to the heat of combustion of a
charge air and combustible fluid, and the air or other fluid which may have been
in front of the piston e in the cylinder will be forced out through the valve
At the end of the stroke the exhaust valve-not shown, (the passage to which is
designated ) is opened and the products of combustion at terminal pressure
allowed to escape in the usual way, after which the return stroke of the piston
follows. In and by this stroke on the working or combustion side of the piston,
the products of combustion filling the cylinder at atmospheric pressure are expelled
to the extent of the volume displaced by the piston (that portion of products in
the combustion chamber a¹ still remaining); and in the front ond of the cylinder
the fluid from the chamber will be extracted through the valve i, its return
stroke being prevented by such valve (and assuming a prior cycle to have been
performed the chamber e will already have been evacuated to the extent of one similar
stroke of the piston). When the piston has arrived at or near the inner limit of its
stroke, the exhaust valve is closed and communication is formed between the outside
atmosphere and the chamber c by way of the combustion chamber a', by opening the
valves and these valves being operated mechanically by some suitable part of the
engine. At this stage of the cycle the whole of the products of combustion will have
been removed from the cylinder and the combustion chamber a¹ will be filled with
fresh atmospheric air. The valve is then closed and the piston e goes on its next
outward stroke, causing air (or air and combustible fluid as the case may be) to follow
it, such fluids passing into the cylinder past the valve g, the fluid in front of the piston
in this stroke being forced out past the valve j. The cylinder behind the piston being
now charged with air, or air and gas or petroleum, now returns and compresses such
charge within the combustion chamber a'; the chamber c at the same time being
evacuated by such stroke in the manner previously described. The compressed charge
being already combustible by the indraught or forcing in of suitable quantity of com-
bustible gas or petroleum spray, is ignited by any suitable igniting device, and the
foregoing described cycle is repeated.
f
i
If gas is introduced into the cylinder by the forward movement of the piston it
may take place in conjunction with the air introduced in that stroke through the
valve 9. The introduction of gas if effected by and on the forward stroke of the
cylinder is controlled by any suitable device or means; or, if injected by a pump it
may take place through the valve 9 or at any suitable point: the valve g is preferably
operated mechanically from a suitable working part of the engine. These features as
regards the introduction of gas or combustible fluid may be taken to apply to all the
examples herein described.
As regards combustion chamber a and piston e, the shape of the former, and the
provision of the cone e¹ upon the latter, together with the disposition relatively of the
valve g, annular part d and piston c, cause the removal or displacement of the products
of combustion remaining in the cylinder, after the positive expulsion of the greater
part thereof by the piston, in a most effectual way; that is to say, these things
distribute the air or cause it to flow in such a manner as to sweep out the chamber
with little or no mixing or to no practical extent, and this holds good whether such
air flows from the narrow end of the cylinder to the annular part d, or whether it
flows from the port towards and out of the narrow end of said chamber; and as far
as the above construction and operation is concerned, I claim effecting the remaining
products of combustion in the chamber by a vacuum as described, or by a
charge of air previously compressed (say from about 2 to 5 lbs. pressure) and
caused to pass into or through said combustion chamber. In the latter case, the
chamber c would serve as a low pressure compressed air reservoir and the front of the
cylinder as an air compressing pump, the valves on or in connection with it of course
being arranged and adapted to operate to suit these conditions-that is, conversely to
that already described.
с
These latter particulars and features respecting compressed air also hold good in all
cases herein described or involved.
In Figure 2 is shown an engine operating similarly to that described with reference

page_text: to Figure 1, but has a trunk piston rod e² in lieu of a solid one. By this construction
the piston can be coupled direct by a connecting rod to the crank pin of the engine;
the annular spade between the trunk e² and the walls of the cylinder a, which serve
as the vacuum pump or compressed air pump as the case may be, being sufficient, in
a four stroke cycle engine, to cause the effective removal of the products of combustion
from the combustion chamber a¹ as previously described.
Figures 2 and 2B illustrate an engine constructed after the manner set forth and
illustrated in the specification of Letters Patent granted to H. H. Hossack No. 88887,
but in this case some of the products of combustion behind the piston are expelled by
the return stroke of the piston and the remaining products being expelled or removed
from the chamber a¹ by a vacuum, when in the position shown in the Figure; such
vacuum being created in the chamber c by the descent of the piston, and the said
removal of products of combustion being effected in the manner set forth already with
reference to Figure 1. The chamber c as in the above cited Specification forms part
of the frame and supports the crank and main gear of the engine, and encloses the
crank and connecting rod.
C
Figure 2 is a detail of a double ported slide valve hk, controlling communication
between the interior of the cylinder, by way of the annular port d, and the chamber c
and exhaust port k, respectively. ¹ is a pipe or conduit between the valve h, k,
and the chamber c.
are the vacuum and exhaust ports, respectively, of the
valve hk. The valve is worked so that these passages communicate with the cylinder
port dat the proper times, the valve covering the port d' at other times as will be
understood.
In this example, in one revolution of the crank, the piston will rise and fall and
have no effect as regards creating a vacuum for the removal of products.
The examples so far as described employ only one effective stroke in four on one
side of the piston.
Figure 3 illustrates an engine, and Figure 4 its diagram of operations, in which an
effective stroke is obtained, for one, side of the piston, for every revolution of the
crank. In this case the annular port d and its passages into the cylinder, are deposed
about rd of the distance traversed by the piston inwards, that is, from the outer
end of its stroke, as shown in the diagrain. The operation in this case is as
follows:-
-
Assuming a combustible charge to be within the chamber a' and to be ignited, the
piston is pressed forward by the resulting pressure of gases in the usual way. When
at or near the outer end of its stroke the exhaust valve is opened. and the products
at terminal pressure allowed to escape, and it (the exhaust valve) is kept open
until the piston nearly reaches the passages of the port d, when it is closed, and
communication is formed between the interior of the cylinder and the chamber
by opening the valve (shown in dotted lines), and the vacuum created in the
chamber, by the action of the piston and the front portion of the cylinder, causes
air to enter through the valve g and sweep out the remaining products of com-
bustion through the port d into the chamber c, i.e. substantially as described with
reference to Figure 1. The valves and are then closed and the air behind
the piston in the remaining portion of the inward stroke is compressed into the
combustion chamber a¹. Gas, vapour or petroleum spray, is injected or introduced
into the air in any suitable known way to render the charge combustible, when it is
ignited and the cycle of operations, as described, repeated.
Compressed air, as above stated, may be used instead of the vacuum in this case.
An engine operating according to the diagram as shown in the drawings, and as
above described, would operate economically, inasmuch as the measure of combustible
charge, is the space swept by of the stroke of the piston of the whole stroke, and
this may he varied, and consequently a greater degree of expansion than the usual one
would be obtained. The combustion chamber in this case should be made smaller
relatively to the capacity of the cylinder than engines working on different cycles
(such as that described with reference to Figure 1) to obtain the same initial pressure
if other things are to be equal.

page_text: In Figures 5 and 6 a compound gas and air or petroleum engine is illustrated.
The cylinders a and b are connected together (as are also the pistons e and f) and are
of different diameters.
When the pistons of the engine are in the position shown in Figure 5, the valve ³.
is opened (that is after an effective stroke), and communication formed by way of the
passage and port between the cylinder a and the cylinder in front of the
piston. The products of combustion thus admitted to the front of the large piston f
owing the differential diameters of the two pistons, press them backwards, and so.
utilize the products of combustion from the initial cylinder. When the pistons have
arrived at or near the return end of their stroke the exhaust valve k is opened to.
allow the products of combustion at terminal pressure to escape, and then closed; and
then communication between the interior of the combustion chamber a¹ and the
chamber c is made, and the remaining products of combustion swept out in the same
manner as set forth with reference to Figure 1.
The chamber c is exhausted (or charged with compressed air as the case may be) by
the rear end of the cylinder and the rear side of the piston f, the space swept through
being annular and formed by the piston e as shown.
In a compound engine, having one effective stroke in four, of this type, two strokes.
of the piston (that is in front of it) may be idle strokes, or used for pumping,
according to the purposes and circumstances for and in which the engine is used.
If the engine works with one effective stroke for every revolution of the crank,
then the combustible charge would be preferably introduced by separate forcing
apparatus.
With reference to Figure 7, the compound engine herein shown differs from that
described with reference to Figure 5 in that the high and low pressure cylinders are
separate structures, that is, they are arranged side by side instead of in line and con-
nected, and the pistons at dead centres are at the different extremities of their respective
strokes; that is, the cranks of these engines are set at 180 degrees to each other.
This engine works in the same manner as that set forth with reference to Fig. 5;
namely, when the initial piston e is at the end of an effective stroke and in the position
shown in the Figure, communication between the cylinder a and the bottom of
the cylinder b, behind its piston, is made by the slide valve hk, and this communica-
tion is maintained during the whole or greater part of the instroke of piston a and
the outstroke of piston. At the termination of these strokes the communication is
broken off by moving the valve hk forward, and communication between the annular
space, between the trunk ee in the front part of the cylinder (within which a partial
vacuum exists), and the combustion chamber al by way of the port 2 of the valve hik
and the passage is made, whereby atmospheric air is introduced through the valve g
into the combustion chamber a', and sweeps the products of combustion out of it
through the port d. This communication is then broken and the engine, if working
with an effective stroke for each revolution of crank, is provided, by suitable
means, with a fresh combustible charge and the operations repeated.
The products of combustion in the cylinder behind and at the outer end of
the stroke of its piston fare, during the return stroke, forced out by way of the
passage or port 1, and the fluid in the annular space in front of the piston is
also forced out on the next outstroke through a valve similar to j, or through a
suitable port in the valve h k.
This engine, when working with one effective stroke in four, for one side of
the piston, instead of having a combustible charge introduced into the chamber a'
as just described, the next forward stroke of piston a is utilized to introduce a
charge of air or air and combustible fluid, and this charge is compressed in the
return stroke. The two corresponding strokes of the piston f of the cylinder 6
behind its piston being idle, or used for any desired purpose; and the strokes in
front of the piston being utilized to exhaust a vacuum chamber (or compressed
air into a reservoir as the case may be) in communication with such cylinder, as
described with reference to Figure 5.
The construction of engine shown in Figure 8 is substantially similar to that

page_text: shown in Figure 7, but is more particularly applicable for an engine having one
effective stroke in four, as one forward and one backward stroke of the low
pressure piston f are utilized as a pump to exhaust, or compress air into a chamber
or reservoir, such as e, hereinbefore mentioned, the other two strokes being utilized
in connection with the utilization and expansion of the products of combustion
from the cylinder a, in the manner set forth with reference to. Figure 7. i is
the non return valve between the cylinder and this chamber, when used as a
vacuum chamber, and is the passage in the case or cover of the valve hk
which is in communication with said chamber. The pumping stroke of the cylinder b
above named, exhausts said chamber in the forward stroke of the piston, and
the port of the valve his caused to be so placed as to put this chamber, by
way of the passage and the annular port d, in communication with the com-
bustion chamber a¹. The moment at which this is done the remaining products
of combustion in the chamber a are allowed to flow into this chamber in the
manner previously described. The fluid from the cylinder b, after utilization of
the charge of the gas, from the cylinder a, in it, are expelled by the ports &
and valve cover.
If this engine is adapted to work with an effective stroke for every revolution
of the crank the remaining products of combustion in the chamber a', after the
positive expulsion of products by the return of the piston e may be removed or
expelled by atmospheric air introduced by any suitable means, such for instance
as those herein before mentioned; that is, the front portion of the cylinder a may
serve as an air compressing or vacuum pump, or any other equivalent suitable
means may be employed.
It will be seen that the construction of low pressure cylinder in this case is a
simpler one than that shown in Figure 7 its piston being an ordinary trunk
piston, as is also the piston e, and both pistons are coupled to crank pins, directly,
by connecting rods said cranks being set at degrees to each other.
; A modified form of engine shown in Figure 8 may consist of one in which
two high pressure and one low pressure cylinders are used, such low pressure
cylinder taking the products and using them both from the high pressure cylinder,
say at different sides of its piston.
Another modified arrangement of compound engine may consist in disposing
tho high and low pressure cylinder opposite each other in line, and adapted to
operate upon the crank according to the construction of the engine now known
as the "Stockport" Gas Engine.
In compound engines according to this Invention air or other fluid is compressed
in the passages and low pressure cylinder prior to, and at the moment when com-
*munication between said cylinder and the high pressure cylinder (or a receiver
.connected therewith) is made, so that when the gases are freed from the high
pressure cylinder to the low, practically no drop of pressure shall take place.
This pressure must therefore be that of or nearly equal to the pressure in the
high pressure cylinder at the moment of release, and it may be most conveniently
obtained by closing the escape valve or exhaust valve to such cylinder at the correct
moment in its stroke, prior to receiving the gases from the high pressure cylinder.
By these means a greater efficiency, other things being equal, is obtained.
Further, in compound engines, in order to obtain a good and effective mean
pressure on the low pressure piston, the combustible charge introduced into the
combustion chamber of the initial cylinder should when at atmospheric pressure
be of greater bulk than the capacity of such initial cylinder, say from a quarter
to a half greater. The capacity therefore of the combustion chamber should, if it
is desired to have the same compression as another engine working on similar
slines, be larger than that of such an engine, in order to obtain the same com-
pression. The extra volume may be introduced by the low pressure cylinder; or
it may be done by the high, with a supplemental charge suitably introduced; or
in any suitable way.
The word petroleum used herein is employed to designate and includes all

page_text: hydro-carbon mineral oils or spirits combustible in the form of vapour, or of
spray, or when in an atomised or comminuted form, and mixed with air.
The compression of the combustible charge prior to ignition, is carried to any
suitable degree, such for instance as those ordinarily employed in existing gas
engines.
It is to be understood that improvements herein described or some of them, as
the case will permit, are applicable to various types of gas engines now made
and used, such for instance as those known as the "Stockport," "Clarke,” “Otto,”
and others.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I would state that
it is to be understood that this invention is not confined to the things particularly as
herein specified, and that it is more or less applicable to various kinds of air and gas
or petroleum engines; and I declare that what I claim in respect of the improvements
in internal combustion heat engines, or in air and gas or petroleum engines,―-set
forth or involved in the above described invention is :-
1. An air and gas or petroleum engine, in which for one side of the piston, one
effective stroke in four is obtained, and subsequently to the effective stroke, the
products of combustion are removed by atmospheric air, caused to pass through the
cylinder to a chamber evacuated by the engine; for the purposes set forth.
2. An air and gas or petroleum engine in which the removal of the products of
combustion of the engine is effected, firstly, partly by the return stroko of the piston,
and the remainder by atmospheric air caused to pass through the cylinder by
putting said cylinder in communication with a chamber evacuated by the engine for
the purposes set forth.
3. An air and gas or petroleum engine in which the removal of products of com-
bustion are effected, firstly, partly by the return stroke of the piston, and the remainder,
by air introduced or conducted from the cylinder annularly or in like fashion, and
guided by a coned body such as the piston, and piston and cylinder; as or substan-
tially as and for the purposes set forth.
4. An air and gas or petroleum engine operating for one side of the piston
according to the following cycle:
:-
(a) An effective stroke in which the combustible mixture is ignited and the
piston pressed forward;
(b) The first instroke in which the piston forces out a part of the products of
combustion, and at or near the end thereof the remaining products are removed
by atmospheric air, whose passage through the cylinder is caused by putting
it in communication with a chamber evacuated by the engine.
(c) The second outstroke in which air, or air and gas or petroleum are intro-
duced; and
(d) The second outstroke in which the fluid introduced in stroke c is compressed
prior to ignition.
5. A compound air and gas or petroleum engine in which the products of combus-
tion in an initial cylinder are, at or near the end of the outward stroke of its piston,
admitted to a cylinder of larger diameter and behind its piston, and communication is
maintained between said cylinders during the return stroke of the piston of the initial
cylinder.
6. A compound air and gas or petroleum engine in which the products of combus-
tion in the initial cylinder are, at or near the end of the outward stroke of its piston,
admitted to a cylinder of larger diameter connected with said initial cylinder, and the
piston of which acts concomitantly with and is connected to said initial piston and
said cylinders being in communication with each other during the stroke following
the effective stroke of the initial piston.
7. A compound air and gas or petroleum engine working, for one side of the high
pressure cylinder, according to the following series of operations :-
:―
(a) An effective stroke of the high pressure or initial cylinder in which the
D

page_text: combustible charge is ignited and the piston pressed forwards; and the fluid
in the low pressure cylinder expelled by the piston thereof;
(b) The return stroke during which the two cylinders are in communication
with each other, and the pressure of gases presses open and forces back the
larger or low pressure piston, and at or near the end of the stroke the terminal
pressure is released, whereupon the remaining products in the combustion
chamber of the initial cylinder are removed by the introduction to said com-
bustion chamber of atmospheric air, and then a combustible charge is intro-
duced, and under pressure therein, is ignited.
8. A compound air and gas or petroleum engine in which the initial and low
pressure cylinders are in communication with each other during the stroke next after
an effective stroke of said initial piston, and the products of combustion remaining in
said initial chamber, are, at or near the end of such stroke, removed by the introduc-
tion of a charge of atmospheric air, such air being introduced by a charge previously
compressed by the engine, or by means of a vacuum, created by the engine, within a
chamber, towards or into which air is allowed to pass by way of the cylinder.
9. A compressed air and gas or petroleum engine operating, for one side of the
piston, according to the following series of operations
(a) An effective stroke, in which the combustible fluid is ignited and presses
forward the piston of the initial or small cylinder;
(b) The return stroke of the said initial piston, in which the initial and low
pressure cylinders are in communication with each other, and the gases of
combustion press forward the piston of said low pressure cylinder, and at or
near the end of which stroke the remaining products of combustion in said
initial cylinder are removed by the introduction of a charge of atmospheric
(c) The stroke in which the products of combustion are forced out of the low
pressure cylinder by the piston thereof and air, or air and gas or petroleum
introduced into the initial cylinder; and
air.
(d) The charge of air, or air and gas or petroleum of said initial cylinder com-
pressed.
The stroke of the low pressure cylinder not mentioned herein, are idle strokes, or
used for any suitable purpose.
10. An air, and gas or petroleum engine operating substantially in the manner set
forth with reference to Figure 1; and also the parts of an engine arranged and
adapted to operate as set forth with reference to said Figure.
11. An air and gas or petroleum engine operating substantially in the manner
set forth with reference to Figure 24; and also the parts of an engine arranged
and adapted to operate as set forth with reference to said Figure.
12. An air and gas or petroleum engine, the parts of which are constructed
and adapted to operate substantially as set forth with reference to Figure 2 of
the Drawings.
13. An air and gas or petroleum engine working, for one side of a piston
thereof with an effective stroke for each revolution of the crank, in which the
products of combustion are removed from the cylinder partly by atmospheric air
introduced into said cylinder, and the introduction of said air is effected by a
charge previously compressed by said engine, or by causing the air to enter said
cylinder by putting it in communication with a chamber previously evacuated by
the engine, the combustible charge being introduced into the combustion chamber
prior to the next effective stroke by suitable pumping or forcing apparatus.
14. An air and gas or petroleum engine operating substantially in the manner
set forth with reference to Figures 3 and 4; and also the parts of an engine
arranged and adapted to operate as set forth with reference to said Figures.
15. An air and gas or petroleum engine operating substantially in the manner
set forth with reference to Figures 5 and 6; and also the parts of an engine
arranged and adapted to operate as set forth with reference to said Figures.
16. An air and gas or petroleum engine operating substantially in the manner

page_text: set forth with reference to Figure 7; and also the parts of an engine arranged
and adapted to operate as set forth with reference to said Figure.
17. An air and gas or petroleum engine operating substantially in the manner
set forth with reference to Figure 8; and also the parts of an engine arranged
and adapted to operate as set forth with reference to said Figure.
18. A compound air and gas or petroleum engine operating in such a manner
as to cause the pressure of fluid in the low pressure cylinder and passages, prior
to or at the moment when the gases are allowed to escape thereto from the high
pressure or initial cylinder (or a receiver in communication therewith), to be
equal to or nearly equal to that of the gases in said high pressure or initial
cylinder.
19. Effecting the compression of fluid in the low pressure cylinder of a com-
pound air and gas or petroleum engine prior to or at the moment the gases are
admitted thereto; as, or substantially as set forth for the purposes specified.
20. An air and gas or petroleum engine having an annular port or ports (such
as d) arranged round said cylinder, at or about the positions with respect to the
point of stroke of its piston, shown in and described with reference to Figures 1,
2, 24, 5, 7 and 8; for the purposes set forth.
21. A compressed air and gas or petroleum engine in which the combustible
charge introduced into or employed or existing in the combustion chamber of the
initial or high pressure cylinder, at the moment of ignition, is of greater volume,
when at atmospheric pressure, than the capacity of the initial or high pressure
cylinder.
Dated the 9th day of July 1800
CHEESBROUGH & ROYSTON,
15, Water Street, Liverpool, Patent Agents.