IMPROVEMENTS IN GAS MOTOR ENGINES AND IN APPARATUS CONNECTED THEREWITH
Year: 1876

page_text: LETTERS PATENT to George Frederick Redfern, of the General Patent Office,
4, South Street, Finsbury, in the County of Middlesex, Patent Agent, for the
Invention of "IMPROVEMENTS IN GAS MOTOR ENGINES AND IN APPARATUS
CONNECTED THEREWITH." A communication fiom abroad by Otto Sack and
Julius Reunert, of Cassel, in the Empire of Germany.
Sealed the 1st December 1876, and dated the 28th August 1876.
PROVISIONAL SPECIFICATION left by the said George Frederick Redfern at
the Office of the Commissioners of Patents on the 28th August 1876.
GEORGE FREDERICK REDFERN, of the General Patent Office, 4, South Street,
Finsbury, in the County of Middlesex, Patent Agent "IMPROVEMENTS IN GAS
MOTOR ENGINES AND IN APPARATUS CONNECTED THEREWITH."
This Invention consists in improvements in the construction of gas motor engines,
whereby the engine occupies less space than those hitherto constructed; the action
of the engine is made more regular or isochronous by the manner in which the
effect produced by the explosion of the mixture of air and gas is utilized; and the
gas employed is produced in an improved apparatus connected with the engine
This improved gas motor engine is applicable to all purposes where the steam
engine is now employed, videlicit, for stationary engines, locomotive engines, marine
engines, engines for driving tram cars, and other similar uses.
It will be sufficient to illustrate the principal of these improvements to describe
the construction of a stationary engine.
A cylinder of suitable construction is provided with a differential piston. The
explosion chamber is placed at the side of the cylinder, and is provided with a slide
valve for admitting at each revolution of the driving shaft the required quantity of
the explosive mixture, which being inflamed enters the cylinder below the piston,
acting on the smaller surface thereof, and before the piston arrives at its highest
point a valve cock allows the mixture to enter above the piston and act on its
farger surface. When the piston has completed its stroke the valve cock, operated
by a link motion, allows the escape of the gases. The cylinder and explosion
chamber are surrounded by water. An arrangement is provided for lubricating the
piston with distilled water, as also the stuffing box. The piston rod is connected to
the crank in the usual manner The driving shafts are made hollow, so that they.

page_text: may serve as reservoirs for oil. The valve cock is operated from a grooved disc on
the crank shaft moving a lever enclosed within a casing to keep it from the water,
but the water circulates through the hollow valve cock. The slide valve is operated
by a tapped disc having a steel tappet, on which slides-a pulley on the forked end
of a rod, a spiral spring serving to bring the slide back to its normal position after
it has been raised. On the top of the slide valve is a pipe coming from the com-
presser, and provided with a suitable valve and a governor for regulating the action
of the throttle valve The compresser is in direct communication with the air
pump, which is double acting, and is operated by gearing The pump sucks in air
and gas, and thoroughly mixes and forces them in a condensed state into the
compresser.
•
The gas for working the improved machine is produced as follows:-The hot air
from the cylinder is caused to pass into a casing enclosing the gas generator, con-
sisting of a metal chamber having a square rod carrying a number of plates, on to
which gasoline, petroleum, kerosine, or other heavy oil is conducted by a copper pipe
The raising of the plates causes the oil to flow downwards, and the heated gases
surounding the whole convert the oil into gas, which collects in the upper part of
the chamber, and is conveyed by means of a pipe to the air pump, the tar formed
being collected in a suitable box.
Pipes are provided for assisting to cool the water surrounding the working
cylinder.
For engines of twenty horse power and upwards the gas is produced in a separate
apparatus.
The mixture of air and gas is ignited by a galvanic battery and inductor, the
spark being produced by a pin on the crank shaft, which comes into contact with a
lever so as to close the circuit at the moment required
An engine suitable for a tramway car or other similar use is constructed on the
same principle as the engine herein-before described, but the arrangement of some
of the parts is modified to suit the different application, and some necessary altera-
tions are made in the details, as will be well understood.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said George Frederick Redfern in the Great Seal Patent Office on the 28th
February 1877.
GEORGE FREDERICK REDFERN, of the General Patent Office, 4, South Street,
Finsbury, in the County of Middlesex, Patent Agent. "IMPROVEMENTS IN GAS 3
MOTOR ENGINES AND IN APPARATUS CONNECTED THEREWITH." A communication
from abroad by Otto Sack and Julius Reunert, of Cassel, in the Empire of
Germany.
This Invention consists in improvements in the construction of gas motor
engines, whereby the engine occupies less space than those hitherto constructed; 4
the action of the engine is made more regular or isochronous by the manner in
which the effect produced by the explosion of the mixture of air and gas is utilized,
and the gas employed is produced in an improved apparatus connected with the
engine.
This improved gas motor engine is applicable to all purposes where the steam 4
engine is now employed, videlicit, for stationary engines, locomotive engines, marine
engines, engines for driving tram cars, and other similar uses.
It will be sufficient to illustrate the principle of these improvements to describe
the construction of a stationary engine
A cylinder of suitable construction is provided with a differential piston. The 5
explosion chamber is placed at the side of the cylinder, and is provided with a slide
yalve for admitting at each revolution of the driving shaft the required quantity of

page_text: the explosive mixture, which being inflamed enters the cylinder below the piston,
acting on the smaller surface thereof; and before the piston arrives at its highest
point a valve cock allows the mixture to enter above the piston and act on its
larger surface When the piston has completed its stroke the valve cock, operated
by a link motion, allows the escape of the gases. The cylinder and explosive
chamber are surrounded by water. An arrangement is provided for lubricating the
piston with distilled water, as also the stuffing box. The piston rod is connected to
the crank in the usual manner. The driving shafts are made hollow, so that they
may serve as reservoirs for oil. The valve cock is operated from a grooved disc on
the crank shaft moving a lever enclosed within a casing to keep it from the water,
but the water circulates through the hollow valve cock The slide valve is operated
by a tapped disc having a steel tappet, on which slides a pulley on the forked end
of a rod, a spiral spring serving to bring the slide back to its normal position after
it has been raised On the top of the slide valve is a pipe coming from the com-
pressor, and provided with a suitable valve and a governor for regulating the action
of the throttle valve. The compressor is in direct communication with the air
pump, which is double acting, and is operated by gearing. The pump sucks in.
air and gas, and thoroughly mixes and forces them in a condensed state into the.
compressor.
The gas for working the improved machine is produced as follows:---The hot air
from the cylinder is caused to pass into a casing inclosing the gas generator, con-
Bisting of a metal chamber having a square rod carrying a number of plates, on to
which gasoline, petroleum, kerosine, or other heavy oil is conducted by a copper pipe.
The raising of the plates causes the oil to flow downwards, and the heated gases
surrounding the whole convert the oil into gas, which collects in the upper part of
the chamber, and is conveyed by means of a pipe to the air pump, the tar formed
being collected in a suitable box.
Pipes are provided for assisting to cool the water surrounding the working
cylinder.
For engines of 6 horse power and upwards the gas is produced in a separate
apparatus.
The mixture of air and gas is ignited by a galvanic battery and inductor, the
spark being produced by a pin on the crank shaft, which comes into contact with a
lever so as to close the circuit at the moment required
An engine suitable for a tramway car, or other similar use is constructed on the .
same principle as the engine herein-before described, but the arrangement of some
of the parts is modified to suit the different application, and soine necessary altera-
tions are made in the details, as will be well understood.
It will thus be seen that the fundamental principle of this machine consists in the
employment of an explosive mixture previously compressed, and which after its
combustion exerts a pressure, at first on a small surface, and in expanding on a
larger surface.
The products of combustion are afterwards utilized for obtaining gus and for
other useful purposes
But to make the Invention better understood I will proceed to describe the same
by reference to the accompanying Drawing, which shews the action of these
machines, the different Figuies representing machines in which the different kinds
of gases are used, according as different circumstances may require
The machines may be worked either by ordinary lighting gas, petroleum, and
such like, or by gas from gas generators.
The working of the different parts of the machine will be herein-after described.
The initial pressure produced by the combustion of a mixture of gas and an, at
first sufficiently powerful, gradually diminishes until it is expended; but as in turn
it exerts itself over a larger surface, an exact compensation is thus produced.
Figure 1 shews the arrangement of the mechanism. A is the cylinder, in which
is-fitted the piston B, supported by a tubular shaft. At the side of the cylinder is .

page_text: placed the explosion chamber C, communicating by means of the opening a with
the slide valve, and by the notch b with the lower surface of the piston, whilst the
cock c is employed alternately for directing the gases over the larger surface of the
piston, and for giving admittance to the products after their expansion, and for
directing them towards other apparatuses. The chamber is besides arranged in such
a manner that the tarry deposits which form in the cylinder can be run therefrom
into the bottom of the said explosion chamber, and all injurious effects will be thus
prevented These deposits are withdrawn from time to time by means of a cock
specially provided for that purpose.
The electric lighter is screwed in the explosion chamber in such a manner as to
be kept constantly cool, and is thus preserved from a rapid deterioration
D is the compressor for bringing to a suitable state of condensation the mixture
of air and gas, which escapes by the valve E, and returns into the explosion chamber
by means of a slide valve provided with a regulator. The compressor receives the
mixture from the air pump F, which is driven by means of gearing from the engine. 1
A jacket filled with water surrounds the pump, so that the gases are maintained
at a low temperature, and when they enter the compressor all loss. of pressure is
avoided.
The differential piston B is connected to the crank by a connecting rod of peculiar
construction, this convenient arrangement produces the desired effect in the best
possible manner. This piston carries at its extremity the ring & to prevent the loss
of the gases, and it receives its direction from the tube c and the cover f.
The mechanism is regulated by the slide valve g and the cock c, actuated by the
crank shaft in the following manner :-The crank consists of two parts, one of which
is a long boss which carries the necessary apparatus for effecting the motion of the
mechanism. The slide valve, the displacement of which is easily effected, is raised
by a steel tappet or cam screwed to the end of the shaft, and then moved back to
its first position by the spiral spring placed in the case i. The cock is moved by
a lever, which carries at its lower part a steel cylinder which enters a slot or groove
in the boss provided to give this lever the required motion. On the other shaft is
fixed a point, which bearing at each turn on a lever employed to close the electric
current, causes the production of the spark in the explosion chamber.
The great speed of the machine necessitates a corresponding lubrication of the
parts. For this purpose the cranks are cast or formed hollow, and serve as receiveis
for the oil, which is poured therefrom not only into the grooves made in the boss, a
but also into the connecting rod mechanism.
The supports of the crank shaft are made of great thickness in consequence of
the rapid wear.
The cooling of all the mechanism is also of great importance.
The cylinder and the explosion chainber are enclosed in boxes filled with water in
such a manner that any surface which may be in contact with the hot. gases is cooled
by this water.
The piston working in a space filled with hot air requires to be moistened and
cooled, which is effected in the following manner:-As all methods of lubricating
possess the disadvantage of being subject to evaporation by high temperatures, this 4
disadvantage has been met by cooling the piston and the cover by means of distilled
water. The lubrication of the piston is then effected as follows.-The tube e is in
communication with the water reservoir, the interior of the piston, and the support
of the connecting rod, the distilled water arrives in the piston, cools it, and after-
wards arrives in the space left between the packing rings; these latter are provided
with numerous small openings, which allow the access of the water towards the
sides of the cylinder. The fine shower thus produced moistens the sides, the piston
then slides more freely, the formation of steam is not so considerable, and the cooling
takes place.
The cover itself is of peculiar construction. Instead of being formed of a uniform
mass it is constructed of several metallic rings, which when placed together form a

page_text: cone. Each ring being cut, the pressure thus renders the closing more complete.
By a special communication with the water receiver the cover is maintained in a
proper state of lubrication.
All is arranged so that the water never reaches a boiling point, and it quickly
loses the heat it acquires; this is effected by a system of tubes k, k, with very thin
sides, in the interior of which other tubes are placed. The water circulates rapidly
within these tubes, and thus loses a great portion of its heat. By this circulation of
the water, or by its employment to lubricate the piston and other parts, a certain
quantity of the water is lost, and should be replaced by distilled water.
The general action of the machine is as follows.-The gases brought by a conduct
pipe into the suction tube of the pump mix with a certain quantity of air. The
pump compresses to a certain extent this mixture, which arrives in the compressor,
which is not simply a receiver but serves to keep up a constant pressure. From
thence the mixture passing through one valve and then through a second, the
opening of which is controlled by a regulator, arrives in a slide valve g, which allows
it to escape at the proper time by the movement itself. As soon as the slide valve
is closed, the lever employed for stopping the curent comes in contact with the
point of the shaft; the electric spark then flies out and effects the combustion of
the mixture. The heated gases immediately exert a strong pressure on the lower
part of the piston, that is to say, on the smaller surface thereof. The piston thus
reaches its highest point The slide valve cock c is arranged in such a manner that
the lessened pressure exerts itself on the upper part of the piston, that is to say, on
its larger surface. As soon as the piston has almost returned to its former position,
the position of the slide valve is such that it allows the still hot gas to escape.
This gas then produces the evaporation of the water which is in the bell G,
Figure 10, and which is utilized to compensate the loss of distilled water, herein-
before described.
Although the construction above described is more simple, it is less convenient
than one more complicated, which requires the direct employment of petroleum or
other oils; this latter offers the advantage of not requiring to be near a gas works,
which is of great importance in moveable machines
The difference of construction is as follows:-Figures 1 to 8 represent the
machine in which petroleum or other similar liquid is employed. The cylinder and
the explosion chamber are arranged in the ordinary manner, except that the gases
which escape therefrom are brought into the space which surrounds the retort H on
all sides, and which, they are employed to heat In the retort is arranged a system
of plates, the object of which is to procure a larger evaporating surface for the
liquids which are introduced therein. The plates are arranged in such a manner
that the flow of the liquids is very slow.
Another advantage of this apparatus is that the parts which most oppose the
evaporation are placed at the bottom, where they are submitted to a higher ten-
perature.
The receiver & serves to gather the tarry products and facilitate their expulsion.
The system of plates is only fixed to the retort cover, and may be easily raised.
It is then much easier to clean them, as the plates are independent of each other,.
and are only kept in their place by a rod passing through the middle.
.
The pipe which brings the petroleum communicates with the receiver, and the
outflow may be easily regulated by means of the cock, which accelerates or dimi-
nishes the action of the machine.
In
When the products which were burning round the retort have generated the
gas, they are still utilized for the production of distilled water
For this purpose
the conduit which forms the passage for these gases is enlarged, and is received by a
copper bell J with thin sides, which from time to time is filled with water.
large machines the necessary water is supplied by a small pump. The steam pro-
duced arrives through a tube in the upper part of the water receiver, and is at once
sufficiently condensed.
Large machines should always carry a special condenser.
.

page_text: The fact of being able to drive the machine by means of the petroleum gives to
this system the advantage of being employed for all purposes and at any time.
They are applicable moreover where moveable machines are required, or for purposes
of locomotion, for they require little space, and may be set up in any place, even in
the open air without difficulty. They may be used with equal advantage for ships.
Although petroleum may be always convenient when employed for stationary
engines, much more economical means may be employed to produce power, and in
many cases the owners of machines may utilize the waste resulting from their
manufactures (such as shavings or paper):
When the machines work by means of gas from gas generators the various parts
are similar to those herein-before described, except that the retort is dispensed with,
and the products of combustion are employed for feeding the distilled water
machines by passing into a space in which a receiver G, Figure 10, containing
water is enclosed
The cylinder L, which serves for the discharge of the products of combustion, is
again surrounded by a jacket, where the air which afterwards enters into the gene-
rator is heated
Referring to Figure 11 of the Drawing I will describe the construction of the
generator. n is the grate beneath which, through the tuyere o, the hot air arrives
by means of the small blower p, Figure 12 (put in action by the machine). The
space where the combustion takes place in the generator is formed of refractory
bricks, whilst the upper part is of cast iron 7 is the cylinder serving for the intro-
duction of the fuel, which may be closed by means of the slide valve r.
The cover
of this cylinder is simply placed thereon, and its closing is insured by means of
sand. The rod s serves to determine the height of the fuel, and consists simply of
a small round iron ferrule, which passes through a stopper 8¹², and may be easily
raised when it is required to charge the cylinder. This rod can also be employed
for breaking up the fuel.
Around the funnel by which the supply is effected is arranged an annular receiver
containing water for the passage of the gas, and constructed in such a manner as to
offer a large cooling surface to these gases, and to hasten the formation of the tar.
As shewn in the Drawing, the gas is made to pass over a bed of water before
arriving at the worm t, which surrounds the charging cylinder. A waste pipe,
which communicates with the tar cistein M, keeps the water at the desired height.
The gas after having passed through the woim, and there deposited the products
of condensation, slides over the liquid surface of the cistern M, and arrives by the
tube into the small gasometer N; this latter insures a constant pressure of the
gas, of which there is always a certain quantity reserved for the requirements of
the machine
The tar cistein is provided with a cock, by means of which the residue from the
production of the gas may be discharged. The generator likewise carries under-
neath the fire-place an ash receiver hermetically closed and capable of being quickly
emptied. It affords also the means of lighting the fire. A door O, also closing
hermetically, serves for cleaning out the fire-place, and moreover for stirring
the fire.
In order to give as much intensity as possible to the fire, and to confine it to the
lower space near the blower, which admits the air previously heated, is arranged a
space R containing a system of plates; these plates are covered with a wide and
thin bed of water, over which the hot air passes, which thus saturates it with water
steam. The whole now passes over the burning fuel, carrying to it water in a state
of very fine division. The water falls drop by drop on to the plates, and is drawn
in in the same proportion By this arrangement the heat is employed to the
greatest possible advantage, and the cost for an equal proportion is considerably less
than by using petroleum.
The distillation of the water is effected in the manner herein-before described.
The steam arrives in a series of tubes V, which allows of a more complete con-
densation.

page_text: Having thus deseribed the nature of the Invention communicated to me, and the
best means with which I am acquainted for carrying the same into effect, what I
claim is,
Firstly. The general arrangement and construction of gas motor engines, sub-
stantially as herein-before described and represented in the accompanying Drawing.
Secondly. The method of compensating for the difference of the pressure produced
by the combustion of the gaseous mixture by causing it to act first on a small
piston surface, and afterwards on a larger surface, as herein-before described.
Thirdly. The method and apparatus for producing the gas in the machine itself,
and the employment of gasoline, kerosine, petroleum, or other heavy oil therefor, as
herein-before described and represented in the accompanying Drawing.
Fourthly The arrangement allowing the employment of gas produced in a gene-
rator specially constructed.
Fifthly. The employment of distilled water for cooling the working cylinder and
other parts, and also for the lubrication of the piston and other parts of the engine,
as herein-before described.
Sixthly. The arrangement for the production of the distilled water in the
machine itself, as herein-before described and represented in the accompanying
Drawing.
In witness whereof, I, the said George Frederick Redfern, have hereto set
my hand and seal, this Twenty-seventh day of February, in the year of
our Lord One thousand eight hundred and seventy-seven.