GAS ENGINES OR MOTORS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said Hector Aylesbury at the
Office of the Commissioners of Patents on the 30th August 1880.
HECTOR AYLESBURY, of the City and County of Bristol.
GAS ENGINES OR MOTORS."
"IMPROVEMENTS IN
a double acting
According to this Invention I construct gas motors with
cylinder, the mixture of air and gas being caused to explode on each side of the
piston, all as hereinafter described.
The air and the gas are admitted by two valves on the same stem at each end
of the cylinder; the fresh mixture of gas and air enters the cylinder at the end
where the explosion has just taken place, the exploded mixture escaping through
one or more apertures at the centre of the cylinder; the said fresh mixture is
compressed in the return stroke of the piston, and when the latter has reached the
end of its stroke this charge is exploded. The connecting rod is by preference
forked and connected to cross heads in one with the piston, and working steam
tight in each side of the cylinder; an ignition slide or other valve at each end of
the cylinder is worked from studs on the cross heads by bell crank or other levers.
The valves for air and gas are worked from the cross heads or by an eccentric or
crank. The cylinder is wholly or partially surrounded by a water jacket and the
exhaust pipe passes through a body of condensing water.
It will be observed that the compression of the fresh charge on one side of the
piston is effected by the explosion of the charge at the opposite end of the piston,
and not as heretofore usually done by the momentum of the fly wheel and other
parts of the engine.
In order to cause a rapid exhaust I may use a pump worked from the cross heads
or from the shaft.
The engine may be horizontal or in any other position. The piston may be
fitted with piston rod instead of combining piston and cross heads, as described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Hector Aylesbury in the Great Seal Patent Office on the 28th
February 1881.
HECTOR AYLESBURY, of the City and County of Bristol.
GAS ENGINES OR MOTORS."
"IMPROVEMENTS IN
According to this Invention I construct gas motors with a double acting cylinder,
the mixture of air and gas being caused to explode on each side of the piston, all
as hereinafter described.
The air and the gas are admitted by two valves on the same stem at each end
of the cylinder; the fresh mixture of gas and air enters the cylinder at the end
where the explosion has just taken place, the exploded mixture escaping through
one or more apertures at the centre of the cylinder; the said fresh mixture is
compressed in the return stroke of the piston, and when the latter has reached the
end of its stroke this charge is exploded. It will thus be observed that I obtain
with the same size of cylinder a four times greater power than, for instance, in
the Otto engine, where the explosion occurs only once for every two revolutions.
The connecting rod is by preference forked and connected to cross heads in one
with the piston, and working steam-tight in each side of the cylinder; an ignition
slide or other valve at each end of the cylinder is worked from studs on the cross-
heads by bell crank or other levers. The valves for air and gas are worked from
the crossheads or by an eccentric or crank. The cylinder is wholly or partially
surrounded by a water jacket, and the exhaust pipe passes through a body of
condensing water.
It will be observed that the compression of the fresh charge on one side of the
piston is effected by the explosion of the charge at the opposite end of the piston,
and not as heretofore usually done by the momentum of the fly wheel and other
parts of the engine.
In order to cause a rapid exhaust I may use a pump worked from the crossheads
or from the shaft.
The engine may be horizontal or in any other position. The piston may be
fitted with piston rod instead of combining piston and crossheads, as described.
In order that my Invention may be more fully understood and readily carried into
effect I will proceed to describe the same with reference to the accompanying
Drawings.
Figure 1 is a longitudinal section through cylinder, and Figure 2 is a transverse
section.
A is the cylinder surrounded by water jacket B; A¹, A¹, are the end covers,
which abut against and are secured to the cylinder proper A; they are each provided
with corresponding apertures a, Figure 2, in order to allow a circulation of water
through the covers A¹ and around the cylinder A, whereby the working parts are
effectually cooled. This part of the Invention will be more particularly described
hereafter.
C is the piston, and c is the cross bar or rod passing through the piston C and
the side dovetailed slides or cross heads D, and to which the connecting rod E is
connected at each side. The slot in each side of the cylinder is of a length corre-
sponding to the stroke, and the cross heads D are of such a length. as to cover these
slots when the piston is at the end of its stroke, so that the gas being admitted at.
the other end of the piston is not allowed to escape, as the slides are made to work
steam-tight, and can be tightened up and adjusted at will. It will be observed
that the lateral slots in the cylinder are covered by the piston when and where the
explosion takes place, and that the cross-head slides D are only exposed to the low
pressure of the exploded charge during its expansion.

page_text: F, F, are the valve chambers, in this case shown situate in the covers A', A¹, for
admitting the mixtures of gas and air into the cylinder; the valves are actuated
by tappets g on the ignition slide valves G. d is the upper valve, in one with the
stem; around this valve stem d is another valve e. f is a sleeve screwed around
the stem d; the end of this sleeve abuts against the under side of the valve e. When
the tappet g on one slide valve G is raised before the completion of its up stroke it
comes against the head of the sleeve and raises the valves d and e, and admits the
gas and air into the cylinder A. When the tappets 9 are not in contact the valves
are kept closed by springs; d' is the spring for closing the valve d, and e¹ the
spring for closing the air valve e.
In Figure 3 d² is the gas inlet, and e² the air inlet, which may be forced in by a
pump in connection with the engine.
When the explosion of the charge takes place there is a fresh charge at the other
side of the piston, which is compressed by reason of the exploded charge sending
the piston to the other end of the cylinder, but just before the end of its stroke the
piston uncovers one or more apertures h in the centre of the cylinder, which is the
exhaust outlet, and through which the exploded charge passes to a condenser m
suspended in the water jacket or chamber B.
The slide valves G are actuated in the following manner :-I is the crank-shaft,
and is an eccentric mounted thereon working a rod connected to an arm i
mounted on a cross shaft i², which has a beam lever J keyed thereon, and the slide
valves G are attached to this beam lever J by links g¹, so that as the arm i' is
reciprocated by means of the rotation of the eccentric, the slide valves G are raised
and lowered respectively the desired distance. A section through one of these valves
is shown at Figure 3.
When the piston is returning and compressing the charge the valve G descends,
and a part of the charge enters through the aperture ¹ into the chamber k of the
valve, which part in its descent is ignited by a flame 1, and when the slide is raised
it carries the ignited gas upwards and explodes the charge in the cylinder by the
aperture and drives the piston away from that end, and simultaneously com-
pressing a fresh charge at the other side of the piston.
When the valve G is in the lowest position the aperture k¹ and chamber /c is
closed, having received a part of the charge in its descent before being raised.
I prefer to cool the cylinder and the valves by water entering from below, and
having an outlet at the top of the jacket.
Figure 4 is a longitudinal section similar to that shown in Figure 1, but different
so far that the valves G are actuated from the underside by a slightly different
arrangement of the levers; but the mode of actuating these slide valves may be
effected in many ways, for example, by cams or eccentrics on a shaft rotated by
gearing from the main shaft.
In Figure 4 it will be seen that on the return stroke of the piston c the exhaust
outlet is nearly covered, and at or about this time one of the tappets g engages with
one of the valves G and admits the fresh charge while the base of the exploded charge
is escaping out through the exhaust h, thus allowing the fresh to be drawn in or
enter freely; but the charge inay be admitted when the piston is at or near the
end of its stroke and the exhaust outlet h almost uncovered, as in the position
shown at Figure 1. The piston at each side is made with a hollow or concavity,
and the end covers A', A¹, similarly formed, so as better to effect both the com-
pression and explosion of the charge; but I do not limit myself to this form of
piston and end chamber.
Instead of the charge being admitted direct into the cylinder the slides G may
be provided with ports, as shown at Figures 5 and 6, which come opposite to the
gas and air inlets at a certain point during the stroke of the said slides G. Figure 5
is a transverse section, and Fig. 6 a plan.
The speed of the engine, and necessarily the rate of admission of the charge, is
regulated by a throttle or other valve and speed governor.

page_text: Figure 7 is a side elevation of an engine constructed according to my Invention.
I is the crank shaft, and E the forked connecting rod.
Figure 8 is a sectional elevation of an engine where only one set of valves is
employed, and the explosions take place only at one side of the cylinder, the fresh
charge being compressed on the return stroke by the impetus of the fly wheel. The
other end of cylinder is quite open.
The gas
1 and 4.
and air may be admitted to the slides G or by valves, as shown at Figures
In this way a connecting rod may be employed, as shown, dispensing with the
dovetailed side slides, as before described.
Figure 9 is a sectional elevation of an engine in which the piston is formed
with a trunk at each end, thus doing away with the cross head slides D, Figures
1 to 4.
Having thus described and ascertained the nature of this Invention, and in what
manner the same is or may be carried into effect, I would have it understood that
I claim,
First. The construction of gas engine in which the fresh explosive charge is
admitted to that end of cylinder where the explosion has just taken place, and
the products of same are exhausting or have just been exhausted by a port in the
middle of the cylinder, the said fresh charge being then compressed by the
explosion of a charge at the opposite side of piston and ignited, substantially as set
forth.
Second. The combination of parts, substantially as herein described, according to
which the exhaust port is arranged in the middle of a cylinder so as to be actuated
by the piston, the said cylinder having air and gas admission valves and ignition
valves operating substantially as set forth.
Third. Constructing a gas engine cylinder with air and gas admission valves of
the form shown and described, and working in combination with ignition slide
valves.
Fourth. Constructing a double acting gas engine cylinder with cross head slides
working in lateral slots in the cylinder, having air and gas inlet valves and ignition
valves at each end, and with the exhaust port in the middle, substantially as
described and shown.
Fifth. The exhaust port
in combination with a condensing pipe or chamber m
surrounded by water, as set forth.
In witness whereof, I, the said Hector Aylesbury, have hereunto set my
hand and seal, this Twenty fourth day of February, in the year of our Lord
One thousand eight hundred and eighty one.
13 ב17T TACT III
HECTOR AYLESBURY. (L.S.)