Improvements in Gas Motors.
Year: 1888

page_text: Date of Application, 2nd Nov., 1888
Complete Specification Left, 2nd Aug., 1889-Accepted, 7th Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in Gas Motors.
A communication from EMIL CAPITAINE, of Berlin, in the German Empire,
Engineer.
1, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex, M.I.M.E.
do hereby declare the nature of this invention to be as follows:-
The present invention relates to gas-motors in which the combustion chamber is not
cooled from the outside by being surrounded by water, and in which the combustible
charge is compressed.
The object of the invention is to keep the walls of the combustion chamber at a
certain degree of temperature because if the walls of the combustion chamber become
too hot a spontaneous or so called pneumatic ignition of the combustible mixture will
take place during the compression i.e. too soon. This spontaneous ignition will
especially take place when petroleum gas is used intead of the common coal-gas.
The invention consists essentially in the automatic cooling of the walls of the com-
bustion chamber when the walls become too hot, which cooling is effected by the
admission of a cooling agent, which admission is regulated or effected by means of the
high temperature itself or by the higher pressure of the combustible mixture.
In a gas motor constructed according to this invention the combustion chamber is
surrounded by an outer jacket leaving a chamber between the two. This chamber is
provided with inlet- and outlet- tubes for air. The inlet tube is in connection with
the end of the cylinder opposite the combustion chamber and in the outlet tube is
arranged a spiral consisting of two flat metal ribbons soldered together, one being
of steel or iron and the other of copper or silver. This metal spiral is similar to
those employed in the so-called metal thermometers and is fastened at one end to the
outlet tube and at the other to the spindle of a valve.
The air sucked into the cylinder at the side of the piston opposite to the combustion
chamber is during the back stroke of the said piston partly driven out through the
before-mentioned inlet tube connecting the chamber round the combustion chamber
with this end of the cylinder, and this air will pass out through the outlet tube in
which the metal spiral is placed. During the passage round the walls of the com-
bustion chamber the air will be heated and communicate this heat to the metal spiral
which is so adjusted that if the heat is too great, it will turn the spindle of the valve to
which it is attached and so open it and allow water to flow round the walls of the
combustion chamber to cool the latter. The cooling of the temperature will enable
the metal spiral to return into its normal position and to close the valve. The spiral
turns the valve spindle in consequence of the different expansion of the two metal
ribbons when heated.
An alternative arrangement for cooling the walls of the combustion chamber consists
as follows:
Next to the cylinder of the motor is arranged a small cylinder the closed end of
which is connected with the combustion chamber. Into this small cylinder fits a piston
which is under the influence of a spring and provided with a rod. An arm suitably
pivotted and connected to an eccentric on the shaft of the motor is so adjusted that the
said arm stands in the same line as the rod of the small piston and bears against this
rod at the moment when the piston of the motor is closest to the combustion chamber
i.e. when the combustion takes place. Should the combustion take place too soon
by the walls of the combustion chamber being over-heated, the above mentioned
arm would not bear against the rod of the small piston and this latter would be driven
out from its cylinder by the excess of pressure in the combustion chamber overcoming
the force of the spring of the small piston.

page_text: This small piston is formed with an opening passing through it which when the said
piston is driven out from its cylinder registers with a water supply pipe having its
ends in the small cylinder between which ends the solid portion of the piston is inter-
posed when no water is required to pass. The water is suitably conducted to the
hollow walls of the combustion chamber.
Dated this 2nd day of Noval 1000
CUMI TELE
DIEULICATION.
Improvements in Gas Motors.
A communication from EMIL CAPITAINE, of Berlin, in the German Empire,
Engineer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex, M.I.M.E.,
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:
The present invention relates to gas motors in which the combustion chamber is not
cooled from the outside by being surrounded by water and in which the combustible
charge is compressed before its ignition.
The object of the invention is to keep the walls of the combustion chamber at a
certain degree of temperature because if the walls of the combustion chamber become
too hot a spontaneous or so called pneumatic ignition of the combustible mixture will
take place during the compression i.e. too soon. This spontaneous ignition will
especially take place when petroleum gas is used instead of the common coal-gas.
The invention consists essentially in the automatic cooling of the walls of the com-
bustion chamber when the walls become too hot, which cooling is effected by the
admission of a cooling agent which admission is regulated or effected by means of the
high temperature itself or by the higher pressure of the combustible mixture.
In the accompanying drawing a gas engine is represented whose action in general
is like the so-called Otto gas engine.
A is the cylinder surrounded by a casing B. In the intervening space the cooling
water is contained. D is the piston E the combustion chamber F the valve for the
admission of gaseous mixture Ġ the valve for the escape of the products of combustion
this valve G being arranged in the port H. J is the cross head which in the usual
manner is connected to the crank shaft. The dotted circle i indicates the path of the
crank-pin and the circle n that of an eccentric on the said shaft. The eccentric is
connected by a rod m to an elastic arm K' of a bell crank lever K K¹. The arm K
serves as a support for the rod L and piston M which piston fits closely in a
cylinder N. This cylinder communicates with the interior of the combustion chamber
or cylinder by the passage O in such manner that the pressure of gases in the com-
bustion chamber is transmitted to the cylinder and tends to force the piston M down-
wards, while a spring F tends to move the piston M upwards.
The combustion chamber E is surrounded by an outer jacket P leaving a chamber
between the two. This chamber is provided with tubes and R respectively for the
inlet and outlet of air. The inlet tube Q is in connection with the end of the cylinder
opposite the combustion chamber and in the outlet tube R is arranged a spiral S
consisting of two flat metal ribbons laid one over the other, one being of steel or iron
and the other of copper or silver. This metal spiral is similar to those employed in
the so-called metal thermometers and is fastened at one end to the outlet tube R and
at the other to the spindle h of a valve T.
The valve T can turn freely in the casing U. In this valve is formed a passage d
which serves to allow the water to flow froin the pipe V to the pipe W. The piston M
is also formed with a passage d which similarly serves to connect the pipes V
and W.

page_text: v
The operation of the apparatus is as follows:-The piston at its underside draws
air into the lower part of the cylinder partly through the valve and partly through
the opening. Let it now be supposed that the passage is open i.e. the slide
valve t which is secured to the rod L removed from the said port; during the down
stroke of the piston D the air will be driven out from the cylinder the greater part
through the opening w and the smaller part through the passage a pipe Q and into
the space between the casing P and conibustion chamber E. By the contact with
the combustion chamber the air becomes more or less heated in proportion to the
temperature of the said combustion chamber. The metal spiral S turns the spindle h
in a well-known manner in consequence of the varying rates of expansion of the
different metal strips. The valve T is so adjusted in relation to the spiral S that
by a temperature of the combustion chamber of about 300° Cels the passage d will
connect the water conducting pipes V and W. The water will then flow to the
combustion chamber and cool it. As the temperature lowers the temperature of
the air passing through the tube R and around the metal spiral S will close the
valve T and thus cut off the water supply.
The spring is of such strength that it can overcome but will slightly yield to the
highest pressure which may act on the piston M. This highest pressure is attained
when the piston D is in its highest position as represented in the drawing and at the
same moment the explosive mixture is ignited by any of the well-known means as
applied to gas motors.
In this position of the piston the arm K of the lever K K' which is actuated by an
eccentric is below the rod L thus preventing the descent of the piston M. If the
combustion chamber becomes too hot spontaneous combustion of the explosive mixture
will take place during its compression i.e. before the piston D has reached its highest
position and in consequence a decrease of power will result. In such case the lever
arm K has not yet arrived beneath the rod L and the untimely pressure consequent
on the premature ignition of the explosive mixture forces the piston M down and in
this manner connects the pipes V and W by means of the passage d the valve t at the
same time being lowered closes the opening w and opens the passage x.
The water flows through the pipe W either through the opening p to the inlet
valve F and will be drawn in to the combustion chamber and cylinder together with
the explosive mixture or through the branch into the space surrounding the
combustion chamber.
The air forced by the descent of the piston D through the opening X and pipe Q to
the outer surface of the combustion chamber serves to cool the latter. The lever K K'
may be dispensed with if the spring ƒ is of sufficient strength to resist the highest
normal pressure. If the combustion chamber becomes too hot the maximum pressure
of the explosive mixture will increase, considerably and the strength of the spring f
being thereby overcome will be lowered.
It is to be observed that the manner of supplying air and water is of inferior
importance in this invention which does not consist in the construction of the parts
for supplying the water nor the form of construction of the jacket P or of the metal
strips of the spiral S but in the method set forth in the following claims.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is
:-
1. The method of automatically cooling the walls of the combustion chamber
when the temperature thereof rises above a certain degree by means of the varying
rates of expansion of two different metal strips to which the heat of the combustion
chamber is communicated and the motion of which strips is utilized for controlling the
water or air supply to the combustion chamber substantially as herein described.
2. The method of automatically cooling the walls of the combustion chamber when
the temperature thereof rises above a certain degree by means of a piston acted upon
by a spring or the like which piston is moved by the pressure of the gases in case of

page_text: premature production of such pressure and the movement of which piston is utilized
for controlling the water or air supply to the combustion chamber substantially as
herein described.
Dated thin and love of d 1000
W. P. THOMPSON & BOULT,
Agents.