Improvements in and connected with Internal Combustion Engines.
Year: 1895

page_text: Date of Application, 7th May, 1895
Complete Specification Left, 7th Feb., 1896-Accepted, 18th Apr., 1898
Improvements in and connected with Internal Combustion Engines.
I, ALFRED GEORGF MELHUISH, of 208 Chounert Road, Peckhamn, London,
Engineer, do hereby declare the nature of this invention to be as follows:-
The object of this invention is
-
1st To construct a gas or hydrocarbon engine with a trunk piston having two
iameters, a larger and smaller, and fitting a cylinder having corresponding
diameters and so airanging the valves in connection therewith that they act
automatically without the use of cams, levers, or other gear to cause the usual
functions of suction, compression, explosion, and expansion and exhaust to be
completed in one revolution of the crank.
2nd. To so construct and arrange the operative parts of the engine, that the
compressed gases are practically free from mixture with the products of combustion
of the previous explosion
3rd. To so construct the engine that the increased impulsive force due to the
combustion of the uncontaminated gaseous mixture is utilised upon the smaller
diameter of the piston during the whole or approximately the whole of the
outstroke, and then completely exhausting the resulting products partly by its
escape through the exhaust valve direct at a given moment and the remainder by
sitetion into the larger end of the cylinder in which a void has been formed by the
outstroke of the larger piston, said suction causing a simultaneous inflow of new
mixture into the smaller end of the cylinder sufficient to fill it, which on the return
stroke is compressed and the products drawn into the large cylinder expelled by
the larger piston through the exhaust valve.
4th. To so arrange the inlet an and gas valves with or without connection to a
governor that air only is first admitted and then combustible mixture of most
economical proportions but varying volume according to the load or work put upon
the engine whereby if connected to a governor I am enabled to control the speed
and automatically regulate the power of the engine by varying the expansion
instead of altering the proportions of the combustible inixture, or cutting out the
explosion as heretofore, the former being less economical than my method and
the latter prejudicial to the regular working of the engine.
In cariying my invention into practice, form a double piston with a larger
and smaller diameter, the smaller piston being an extended trunk uprising from the
larger diameter and of such a size that their effective areas are about the same, or
one may be larger than the other This double piston is fitted within a cylinder
of corresponding diameters in which at the point corresponding to the end of the
stroke of the smaller piston is a port communicating with the large cylinder, just
above this port and preferably upon the opposite side of the cylinder is another
port closable by a non retuin relief valve opening outwards and constituting the
exhaust valve. At the top of the cylinder which is preferably inverted 18 a valve
opening inwards, the spindle of which forms 01 1B 111 connection with the gas valve
80 arranged that any predetermined quantity of air only can be drawn into the
cylinder before the gas valve opeus, or it the said valve be in connection with a
governor the quantity of air first drawn into the cylinder can be varied to suit the
varying conditions of load.
A cock may be fitted to the larger end of the cylinder for the purpose of

page_text: facilitating the starting of the engine, the consecutive action of which is as
follows: Assuming that the piston 18 just about to start its first outstroke, the
cock before mentioned is opened to allow air to flow in behind the large diameter
of the piston at the same time the smaller diameter piston is drawing a combustible
mixture into its cylinder through the inlet air and gas valves, the cork communi-
cating with the large cylinder is now closed and the double piston on its stroke
compresses the mixture drawn into the smaller end of the cylinder, and expels the
a from the larger cylinder through the exhaust valve by way of a recess formed
in the trunk of the small pistou.
The charge is then exploded and power developed during the whole of the
outstroke until the end of the small pistou has uncovered the exhaust port when
any pressure remaining escapes by the non return valve to establish an equilibrium
a slight further movement uncovers the port communicating with the larger
cylinder, in which a vacuum has been formed by the outstroke of the large piston,
with the result that the products remaining in the small cylinder rush minediately
into the vacuum and a new charge is drawn into the small cylinder through the
inlet valve owing to the vacuumn the volume of said now chaige being of course
equal to the effective vacuum of the large cylinder which is of a capacity equal or
greater than the volume of the small cylinder.
At the commencement of the instroke the end of the piston passes the communi-
cating and exhaust ports and thus cut off any connection between the large
cylinder and the small one above the piston but opens communication with said
laiger cylinder and the exhaust valve by the recess in the small tank before
mentioned, so that at the completion of the usti oke the charge is compressed to
the end of the small cylinder and the products expelled from the larger cylinder
and so on during every revolution of the crank.
From the foregoing it will be seen that the small piston in its movement past the
exhaust port alternately puts the small and large cylinder in communication with
the atmosphere, so that the same valve acts alternately as a relief for one cylinder
and an exhaust valve for the other without interfering with the other functions of
either cylinder.
.
If a small change only is required, whether under the control of the governor of
by hand, I arrange that the gas valve is opened later by the air valve spindle, so
that a greater or less amount of an only enters first, and the combustible mixture
last, which remains stratified above the an and not intermixed with it, so that a
Jess volume of mixture is exploded and the greatest economical result is obtained
thereby.
Dated this 7th day of May 1895.
COMPLETE SPECIFICATION.
Improvements in and connected with Internal Combustion Engines.
1 ALFRED GEORGE MELHUISH of 208, Choumert Road, Peckham London,
Engineer, do hereby declare the nature of this invention and in what manner the
ɛame is to be performed to be particularly described and ascertained in and by the
following statement :-
The object of this invention is:
1st. To construct a gas or hydrocarbon engine with a trunk piston having two
diameters, large and smaller and fitting a cylinder having corresponding
diameters and so arranging the valves in connection therewith that they act
automatically without the use of cains, levers, or other gear to cause the usual
functions of suction, compression, explosion, and expausion and exhaust, to be
completed in one revolution of the crank.

page_text: 2nd. To so construct and arrange the operative parts of the engine that the
compressed gases are practically free from mixture with the products of combustion
of the previous explosion.
3rd. To so construct the engine that the increased impulsive force due to the
combustion of the uncontaminated gaseous mixture is utilized upon the smaller
diameter of the piston during the whole or approximately the whole of the
outstroke and then completely exhausting the resulting products partly by its
escape through the exhaust valve direct at a given moment and the iemainder by
suction into the larger end of the cylinder in which a void has been formed by the
outstroke of the larger piston, said suction causing a simultaneous inflow of new
mixture into the smaller end of the cylinder sufficient to fill it, which on the return
stroke is compressed and the products drawn into the larger cylinder expelled by
the larger piston through the exhaust valve
4th To so arrange the inlet an and gas valves with or without connection to a
governo that an only is first admitted and then combustible mixture of inost
economical proportion, but varying volume according to the load or work put
upon the engine whereby if connected to a governor I am enabled to control the
speed and automatically regulate the power of the engine by varying the expansion
nstead of altering the proportions of the combustible mixture, or cutting out the
explosion as heretofore, the former being less economical than my method and the
latter prejudicial to the regular working of the engine.
In cariying my invention into practice, I form a double piston with a larger and
smaller diameter, Figs. 1 2 & 3 the smaller piston A being an extended trunk
upusing from the laige diameter piston B and of such a size that then effective
areas are about the same, or one may be larger than the other. This double piston
is fitted within a cylinder C of corresponding diameters A', B', in which at the
point corresponding to the end of the stroke of the smaller piston A is a port D
communicating with the large cylinder B' just above this poit D and preferably
upon the opposite side of the cylinder is another port E closable by a non-return
relief valve F opening outwards and constituting the exhaust valve. At the top
of the cylinder which is preferably invented is a valve G opening inwards, the
spindle H of which forms or 18 in connection with the gas valve I so arranged that
any predetermined quantity of an only can be diawn into the cylinder A before
the gas valve I opens, or if the said valve I be in connection with say a governor J
the quantity of air first diawn into the cylinder A can be varied to suit the varying
conditions of load, in the manner hereinafter explained.
A cock K may be fitted to the larger end B of the cylinder C for the purpose
of facilitating the starting of the engine, the consocutive action of which is as
follows:-
Assuming that the piston A, B, is just about to start its first outstroke the cock K
before mentioned is opened to allow air to flow in behind the lager diameter B of
the piston at the same time the smaller diameter piston A is drawing a combustible
mixture into its cylinder though the inlet air and gas valves G, I, the cock K
communicating with the large cylinder is now closed and the double piston A, B,
on its instroke compresses the mixture drawn into the smaller end of the cylinder A'
and expels the air from the larger cylinder B' through the exhaust valve F by
way of a recess L formed in the trunk of the small piston, and as particularly
shewn by the dotted lines in Figure 2.
The charge is then exploded in the usual way by a hot tube say at M, and power
developed during the whole of the outstroke until the end of the small piston has
uncovered the exhaust port E when any pressure remaining escapes by the non-
return valve to establish an equilibrium in the small cylinder A' that is to say to
atmospheric pressure, a slight further movement uncovers the port D communicating
with the large cylinder B in which a vacuum has been formed, or partially
formed by the outstroke of said large piston B' with the result that the products
of combustion remaining in the small cylinder rush immediately into the vacuum
and a new change is thereby simultaneously drawn into the small cylinder A'

page_text: through the inlet valve G owing to the said vacuum. The volume of the new
charge being of course equal to the effective vacuum of the large cylinder which
18 of a capacity equal or greater than the volume of the small cylinder which 18
therefore now filled with uncontaminated combustible mixture.
At the commencement of the instroke the end of the piston A passes the
communicating and exhaust ports E and Diespectively and thus cut off any
connection between the large cylinder and the space above the piston A, but opens
communication with the said laiger cylinder B and the exhaust valve F by the
recess in the small trunk A before mentioned, so that at the completion of the
ustioke the change is compressed to the space in end of small cylinder and the pro-
ducts expelled from the larger cylinder and so on duing every revolution of the
crank.
From the foregoing it will be seen that the small piston in its movement past
the exhaust port alternately puts the small and laige cylinder in communication
with the atmosphere, so that the same valve acts alternately as a relief for one
cylinder and an exhaust valve for the other without interfering with the other
functions of either cylinder
If a small charge only is required, whether under the control of the governor
or by hand arrange that the gas valve 18 opened later by the air valve spindle, so
that a greater or less amount of an only enters hrst, and the combustible mixture
last, which remains stratified above the au, and not intermixed with it so that a
less volume of mixture is exploded and the greatest economical result is obtained
thereby as will be clearly understood from the following, that is to say, on the end
of the valve spindle 18 pivotted a cain plate N that is connected by the link P to
the rocking lever Q operated by any kind of coutufugal governor J.
The inlet valve G is of such atea that the incoming gases, open it to its full
extent that is about one quarter its diameter which gives the valve spindle a good
amount of movement for the tappet R on the end of the spindle S of the valve G
to press upon the cam plate and open the gas valve.
It is obvious that if the cam plate is in the position shewn in Figure 1, the valves
open aud close simultaneously and allow gas and air to How together into the
linder A. the air entering by the holes S and the gas by the passage T consti-
tuting a full charge of combustible mixture. But if on the other hand the cam
plate be moved to the position shewn at Figure 2, the mlet valve will open about
seven eighths of its extent before the gas valve is touched, consequently the first
seven eighths of the new charge that enters the cylinder will consist of air only
and the latter part of the charge namely one eighth will consist of combustible
mixture which by reason of its entering last and being of lighter specific gravity
will remain stratified and buoyant at the top of the cylinder and be ignited by the
hot tube Therefore with the varying position of the cam plate between that
shewn at Figure 1 and that at Figue 2 a varying combustible charge will enter
the cylinder, yet under all conditions the exploded gases will be completely
exhausted, the space beyond that occupied by the combustible mixture being pure
nir only.
In some cases, such for instance in a slow moving engine, I prefer not to use the
side port in the cylinder, but instead use a port a in the face of the piston ns in
Fig. 4 that corresponds with the relief port, near the end of its stroke, but which
covers said relief port before the ports D E are opened the exhaust valve Fin
this case being in communication with the larger cylinder only, and the port E
opening into the exhaust pipe above the said exhaust valve
Where two pistons are used such as in Figure 5, one is formed with differential
diameters, the capacity of the large diameter cylinder being sufficient to exhaust
the contents from the space vacated by the two pistons, one of which can be used
to govern the period of entry of the gas and an at T, S, and the other governing
the period of the relief and exhaust functious, but in all cases a piston having
differential diameters is used, and a vacuum formed in the cylinder corresponding
to the large diameter piston whereby 1 am enabled to produce an engine in which

page_text: the products of combustion are always sucked out of the working cylinder, and
the new change only enters the engine the instant before compression takes place,
instead of as in other engines the air or gas and air, being diawn in by oue piston
and then transferred into the other cylinder for compression.
Having now particularly described and ascertained the untune of my inven-
tion and in wbat manner the same is to be performed I declare that what I
claim 19.
1. In internal combustion engines the improved cycle of operations consisting in
forming a vacuum or partial vacuum in a supplementary cylinder and establishing
communication with the working cylinder at the end of the piston's outstroke for
withdrawing the products of combustion of the previous explosion from said
working cylinder into said supplemental y cylinder and simultaneously indrawing
a new charge into the working cylinder and during the pistou's insti oke expelling
the products from said supplementary cylinder, and compressing the charge in the
working cylinder all effected by means of a single crank as set forth.
2. In internal combustion engines so forming and adapting a double piston and
cylinder to each other, that the smaller diameter of said double piston at or near
the end of its power outstroke first uncovers a relief port closed by a non return
valve then uncovering a port or passage between larger diameter cylinder
surrounding the smaller piston and the smaller diameter cylinder beyond the piston
and on its instroke to open communication from said laige diameter cylinder to
the atmosphere, thereby effecting a complete cycle of operations in one rovolution
of a single crank as described and in the manner substantially as shown in the
annexed drawings
3. In internal combustion engines the combination of a trunk piston formed with
two diameters AB of approximately the same effective areas, and a recess or
port L in the smaller diameter A of said trunk piston with a cylinder or cylinders
of corresponding diameters formed with a port, E, closable by a non return valve F
and a passage of pipe D connecting the two cylinders all arranged substantially in
the position shewn in Figure 1 and all operated in the manner and for the purpose
described.
4. The modified aangement and position of the exhaust valve and manner of
effecting the relief of pressure in the power cylinder as described and shewn with
reference to Figure 4.
5. The particular arrangement of gas and an inlet valve and method of governing
the speed of the engine without altering the mixture or cutting out explosions as
described and shewn with reference to Figures 1 and 2
Dated this 7th day of February 1896.
ALFRED GEORGE MELHUISH.