Improvements in Gas, Oil, and like Engines.
Year: 1895

page_text: Date of Application, 27th Nov., 1895
Comalata Cannifination Loft
27th Aug 1906 Accented
17th Out 1806
PROVISIONAL SPECIFICATION.
Improvements in Gas, Oil, and like Engines.
I, GORDON CUMMINGS MARKS, of 82 Dudley Terrace, Grantham, in the
County of Lincoln, Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention has for its object to provide means whereby the explosive mixture
taken into the cylinder of a gas, oil, or like engine during the inhaling or outward
stroke may be compressed to the required degree during the compressing or inward
stroke, whatever the volume of the explosive mixture may be.
For this purpose I arrange to work in the engine cylinder a secondary piston
upon the outer side of which presses a coil or other spring of such strength that it
can only be held in compression by a force equal to the degree of compression
required multiplied by the area of the secondary piston.
Projecting from the back of this secondary piston is a ram working in a
hydraulic cylinder formed on or attached to the engine cover, and the inlet and
outlet to and froin which is supplied with fluid from any suitable source governed
hy a valve operated by the aid of hit and miss, crank, or other mechanism to close
it at the end of the compression stroke of the engine piston.
By this arrangement the secondary piston can only be forced back during the
compression stroke after the explosive mixture has attained the desired degree of
compression, owing to the fact that the pressure of the spring has to be first over-
come, whilst upon the completion of this compression stroke the inlet and outlet
valve of the hydraulic cylinder is closed and a hydraulic buffer so formed, which
will release the spring of any undue pressure when the maximum pressure in the
cylinder is reached by the firing of the explosive mixture therein by the usual
methods.
Where found more convenient or desirable, instead of operating the secondary
piston to regulate the cubical capacity of the engine cylinder directly by a spring
or spiral, this may be effected by the indirect pressure of a weight, spring, or fluid
pressure, or the like acting upon one end of a lever the opposite end of which is
connected to a piston valve arranged to govern a small outlet from the hydraulic
cylinder, a second inlet and outlet being provided in said cylinder governed by a
non-return valve, through which water or other fluid may be supplied to said
cylinder under sufficient pressure to force the secondary piston inwards during the
inhaling stroke of the engine piston. And a third valve to shut off all com-
munication with the hydraulic cylinder when the piston is doing its outward or
propelling stroke. To make the hydraulic cylinder a buffer again.
In this arrangement pressure of the weight spring or the like is such as to
prevent the movement of the secondary piston during the compression stroke until
the explosive mixture has attained the desired degree of compression, when the
piston valve will be forced outwards and when the retrograde movement of the
secondary piston is considerable, open the outlet from the hydraulic cylinder and
permit of the escape of some of the fluid contained therein, closing said outlet again
however immediately the pressure within the hydraulic cylinder falls below that
required to maintain the desired degree of compression.
Dated his orth
how 1805
"
CASTLE SMITH,
'Invention " Office, Mitre Court, Fleet Street, London, E.C.,
Agent for the Applicant.

page_text: I GORDON CUMMINGS MARKS formerly of 82 Dudley Terrace Grantham in
the County of Lincoln. but now of 4 St. Oswald's Road West Brompton in the
County of London Engineer do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention has for its object to provide means whereby the explosive mixture
taken into the cylinder of a gas oil or like engine during the inhaling or outward
stroke may be compressed to the required degree during the compressing or inward
stroke whatever the volume of the explosive mixture may be. To obtain this
I employ a secondary piston which is fitted with a ring or rings working air-tight
in the compression chamber of the engines cylinder from one side of this piston
I have a ram attached or formed on to the side of the piston which fits air tight
in a hydraulic cylinder formed on or attached to the engine cover.
At the opposite end of the hydraulic cylinder is a. non-return valve. Again
leading from the hydraulic cylinder is a duct which can be closed by means of a
valve worked either by the engine or other suitable means as I may think fit and
which I will call the intermediate valve. The aforementioned duct after passing
the intermediate valve leads to a smaller cylinder and plunger, which I will call
the equalising cylinder and. plunger. This equalising plunger has at its one end
attached the resistance of a weight or spring or any other suitable arrangement
whereby the pressure on the secondary piston is balanced by this equalising ram
by means of the transmission of pressure by any fluid through the duct and
hydraulic cylinder.
In this pressure equalising cylinder is an outlet either to the water jacket of the
engine or other receptacle according to the fluid used in the hydraulic cylinder.
This outlet is so arranged that during the compression stroke of the engine and
the charge having reached the maximum desirable degree of compression, and the
engine not having completed its compression stroke, the secondary piston will recede
until the end of the compression stroke of the engine, at the same time exerting a
pressure on the fluid in the hydraulic cylinder which will be transmitted to the
equalising cylinder by means of the duct, the intermediate valve being open all
through the compression stroke, but closed immediately at the completion of the
compression stroke thus forming a hydraulic buffer for the secondary piston during
the outward stroke of the engine propelled by the explosion and expansion of the
charge compressed. When this intermediate valve is open. it will allow the
pressure from the hydraulic cylinder to be transmitted to the ram. or plunger of
the equalising cylinder which will also recede. as the secondary piston thus over-
coming the resistance, of a weight attached at the end of a lever or acting direct,
or the resistance of a spring or the resistance of air or like gasses under compression
until it has uncovered the outlet in the. equalising cylinder, when the water or
other fluid will escape into the water jacket of the engine or other suitable
receptacle, until the end of the compression stroke when the intermediate valve
closes and shuts off all communication with the hydraulic cylinder. The non return
valve is for replenishing the hydraulic. cylinder, and for allowing pressure to be
exerted on the ram end of the secondary piston which will be forced back to its
normal position.
This pressure may be exerted either by having a suitable head of water leading
to the water jacket from which this non: return valve cuts off the communication
from the hydraulic cylinder after the engine has completed its outward stroke upon
the firing of the charge, ori by means of another pressure plunger worked by the
engine, or arranging to keep the intermediate valve closed during a small part of

page_text: the inhaling stroke of the engine and if found necessary to keep the exhaust valve
gas or oil vapour and air inlet valve closed for the same period thus forming a
partial vacuum in the explosion chamber which will cause the secondary piston to
return to the end of its stroke. All valves open against the pressure so that
during the explosion and expansion of the charge, they will be kept well up against
their seats and insure a good lock or buffer for the ram end of the secondary
piston. The resistance acting on the equalising: ram.should be adjustable to reduce.
or increase the degree of compression. of the. explosive mixture in the compression.
chamber.
In an alternative method I employ a spring or coil as resistance to the receding
of the secondary pisten: during the compression. stroke. of the engine which acts
directly at the back of the secondary piston, a ram is formed on or attached to the one
side of the secondary piston as in the previous case and works in a hydraulic cylinder
which is formed on or attached to the engine cover precisely as described in the
former case.
A non return valve is also arranged as before mentioned as also a
valve leading from the hydraulic cylinder to the water jacket or any other suitable
receptacle and which I shall call the hydraulic exhaust valve. During the com-.
pression stroke this valve is kept open by the engine and as the secondary piston
recedes overcoming at the same time the resistance of the spring or coil it discharges
the fluid from the hydraulic cylinder into the water jacket of the engine or other
suitable receptacle, and on the completion of the compression stroke the valve
leading from the hydraulic cylinder and governed by the engine is closed thus
making this hydraulic cylinder a buffer again as described in the former method..
After the explosion and expansion of the charge. the spring drives the secondary
piston to its normal position. In this case also all valves open against the pressure..
Both these methods can be applied to any cycle or type of gas and oil engine and
any method already known can be adopted for varying the volume of the explosive
Fig. 1. is a vertical section of the cylinder and cover showing the secondary
piston the valves and inner cylinder cover forming the hydraulic cylinder of an
engine constructed according to my invention.
Fig. 2. is a vertical section of the engine's cylinder and cover taken through the
lines . y. of Fig. 1.
Fig. 3. is a vertical section of the engine's cylinder and cover showing an
alternative method using the spring or coil S.
A. is the piston B. the duct for the cooling water C. the compression space
D. the secondary piston E. the ram end of the secondary piston which is made
air tight in the hydraulic cylinder by means of a cup leather and guard P is the
inner cover forming the hydraulic cylinder G.
Q. is the liner which is cast with the jacket R.
N. is the outer cover forming a water jacket B.
K. is the equalising cylinder L. is the equalising ram M. is a lever W. is the
weight or resistance. H. is the intermediate valve for shutting off the com-
munication between the hydraulic cylinder G. and the equalising cylinder K. seen
best in Fig. 2 and worked by the engine by means of a lever or cams or other
suitable contrivance. F is a non return valve.
J. is the duct leading from the hydraulic cylinder G. past the intermediate
valve H. and to the equalising cylinder K.
Z. is the outlet from the equalising cylinder K. in this case to the water jacket
or duct B.
S. is a spring or coil the resistance to the secondary piston.
O. is the outlet valve from the hydraulic cylinder G. to the water duct B. and
is worked by the engine by means of levers or cans, being closed during the
ignition of the charge and opened during the compression stroke.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
(1.) In a gas or oil engine a secondary piston with an elongated end forming a
ram which works in a hydraulic cylinder substantially as described and shewn in
Figures 1, 2, and 3 of the drawings.
(2.) A non return valve fitted in the end of the cover which forms the
hydraulic cylinder substantially as described and shewn in Figures 1 and 3 of the
drawings.
(3.) An inner cover to the cylinder which forms the hydraulic cylinder
substantially as described and shewn in Figures 1, 2, and 3 of the drawings.
(4.) An outer cover forming the water jacket substantially as described and
shewn in Figures 1, 2, and 3 of the drawings.
(5.) An intermediate valve between the hydraulic cylinder and the equalising
cylinder substantially as described and shown in Figures 1 and 2 of the drawings.
(6.) An equalising ram and cylinder as substantially described and shown in
Figures 1 and 2 in the drawings.
(7.) A lever and weight or resistance acting on the end of the equalising ram
substantially as described and shown in Figure 1 of the drawings.
(8.) A spring or coil acting as resistance to the secondary piston substantially
as described and shown in Figure 3 of the drawings.
(9.) An outlet valve from the hydraulic cylinder to the water jacket substantially
as described and shown in Fig. 3 of the drawings.
N.B. Claims 8 and 9 refer to the alternative method.
Dated this 26th day of August 1896.
GORDON CUMMINGS MARKS.