IMPROVE- MENTS IN GAS MOTOR ENGINES.
Year: 1879

page_text: LETTERS PATENT to George Gordon Picking and William Hopkins, Engineers;
both of Bow, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN GAS MOTOR ENGINES."..
Sealed the 27th February 1880, and dated the 4th September 1879.
PROVISIONAL SPECIFICATION left by the said George Gordon Picking and
William Hopkins at the Office of the Commissioners of Patents on the 4th
September 1879.
GEORGE GORDON PICKING and. WILLIAM HOPKINS, Engineers, both of Bow, in the
County of Middlesex. IMPROVEMENTS IN GAS MOTOR ENGINES."
"
This Invention relates to improvements in gas motor engines, in which the
piston or pistons in the cylinder or cylinders are actuated by the result of the
combustion of air and inflammable gas or oil.
According to the present Invention the adinission of gas and air to the cylinder
and the ignition of same is controlled by the piston itself, which is made longer
than ordinary and arranged with ports and passages in it, and communicating with
the ends of the cylinder, and passing over corresponding ports in the cylinder so
that at the commencement of the stroke the piston drawing in air and gas and
opening a communication with the gas flame the mixture is ignited through the
piston or cylinder, or both, and the combustion of the charge drives the piston out
to complete its stroke, and on the return stroke draws in a similar charge at the
other end, which is also fired by the piston uncovering a port, and the motion'
continues. By this arrangement the engine can be made single or double acting,
that is to say, drawing in air and gas, and combustion taking place at one end of
the cylinder, or drawing in air and gas, and combustion taking place at both ends
of the cylinder; also they can be made to compress the charge before ignition.
According to one arrangement, the piston being long and having ports and
passages in it, the air is drawn in, also the inflammable gas, the charge ignited,
and the products of combustion expelled without any external slide, the whole
being arranged in the travel of the piston, and is also made single and double
acting, or the air and gas drawn in and ignited partly by the piston and partly by
an external valve actuated by an eccentric or cam:

page_text: According to another arrangement the long piston is fitted with an internal
piston attached by a rod to the cover of the cylinder, so that the outer piston in
passing over ports in the cylinder allows the inner piston to draw in a charge and
at the return stroke to discharge the compressed mixture to the end of the cylinder,
when it is fired through the piston itself, or by an external valve this is made single 5
and double acting, and the force of the explosion and expanding gases is exerted
in the large area of the outer piston.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Gordon. Picking and William, Hopkins in the Great Seal
Patent Office on the 4th March 1880.
GEORGE GORDON PICKING and WILLIAM HOPKINS, Engineers, both of Bow, in the
County of Middlesex. "IMPROVEMENTS IN GAS MOTOR ENGINES."
This Invention relates to improvements in gas motor engines, in which the piston
or pistons in the cylinder or cylinders are actuated by the result of the combustion
of air and inflammable gas or oil.
According to the present Invention the admission of gas and air to the cylinder
and the ignition of same is controlled by the piston itself, which is made longer
than ordinary and arranged with ports and passages in it, and communicating with
the ends of the cylinder and passing over corresponding ports in the cylinder, so
that at the commencement of the stroke the piston drawing in air and gas and
opening a communication with the gas flame the mixture is ignited through the
piston or cylinder, or both, and the combustion of the charge drives the piston out
to complete, its stroke, and, on. the return stroke draws in a similar charge at. the
other end which is also fired, by the piston uncovering a port and the motion
continues. By this arrangement the, engine can be made single or double acting,
that is to say, drawing in air, and gas, and combustion. taking place at one end of
the cylinder, or drawing in air and gas, and combustion taking place at both ends
of the cylinder; also they can be made to compress the charge before ignition..
According to one arrangement, the piston being long and having ports and
passages in it, the air is drawn in, also the inflammable gas, the charge ignited,
and the, products of combustion expelled without any external slide, the whole
being arranged in. the travel of the piston,, and is also made single and double
acting, or the air. and gas drawn in and ignited partly by the piston and partly by
an external valve. actuated by an eccentric or cam.
According to another arrangement the. long piston is fitted with an internal piston
attached by a rod to, the cover of. the cylinder, so that the outer piston in passing
over ports in.the cylinder allows the inner piston to draw in a charge and at the
return stroke to discharge the compressed mixture to the end of the cylinder; when
it is fired: through the piston itself or by an external. valve this is made single
and double acting, and the force of the explosion and expanding gases is exerted
on the large area of the outer piston.

page_text: On the accompanying Drawing, Fig. 1 shows a part longitudinal section of an
engine according to this Invention; Fig. 2 is a plan of same. A is the cylinder;
B, the main piston; C, an inner piston working in the main piston which forms
the cylinder of same. The main piston communicates motion through the piston
rod and connecting rod to the crank shaft, on which is attached ordinary eccentrics
or cams for giving motion through the rods c to the exhaust slide a and the ignition
slide a¹. The piston C is firmly fixed to the cylinder cover, or by means of a bridge
piece D, or other similar means to the cylinder A. E is the emission port governed
by the slide valve F, which is worked from an eccentric or cam; G is the gas inlet
valve with regulating screw H; attached to or near to which is a valve I operated
upon by the governor J, so that the valve I is either open full or completely closed
by means of the lever and small weight K falling over to one side or the other;
Lis the valve for admission of air to the cylinder A; M. is the inlet valve to the
interior of main piston B; N is a port communicating to the opposite inner end of
main piston. The passage O with ordinary valve P (which can be arranged as a
slide valve) communicates inner end of main piston with outer end of main
cylinder A; a' is the slide valve which is worked by an eccentric or cam from
main shaft, and is placed in such a position that it ignites the charge to produce
motion of the piston.
Instead of the gas and air inlet valves being ordinary valves the admission of
gas and air can be controlled by slide valves, as shewn, Fig. 3, worked by eccentrics
or cams from the main shaft, or by a shaft lying parallel with the cylinder driven
by wheels from the main shaft and the slides moved therefrom by cam or eccentrics.
The ignition and admission of gas and air and the emission of the products of
combustion can be controlled by the movement of one slide, which by preference is
made round, as in Fig. 4, or in separate small pistons, as in Fig. 5; Fig. 6 shews
section of a cylinder with a piston longer than its stroke, with ports arranged on
side and bottom of the cylinder by which the admission of gas and air, the ignition
of same, and the emission of the products are governed by the piston itself without
any can or eccentric from main shaft; Fig. 7 is a sectional plan of same cylinder,
shewing the ignition port and exhaust port; Fig. 8, part section shewing the
exhaust port E.
In slides placed as ordinary in gas engines for the purpose of opening and
closing the admission, emission, and igniting ports great difficulty has been
experienced in keeping the slide. valve tight to the slide face; as if external
pressure by springs or otherwise, sufficient to overcome the internal pressure
is put upon the slide, undue friction is the result; to overcome this difficulty we
place the slide valve or valves within the cylinder or within a recess or casing
leading to the cylinder, so that internal pressure tends to keep the valve tight.
against its face, and when there is no internal pressure the friction is reduced to a
minimum and to resist an occasional vacuum in the cylinder, a slight spring only
is necessary to keep the slide up to its face. We prefer to move the slides direct
through a slot in the cover (the inner side of which serves as a slide face) so that
stuffing boxes are not required to move the valves, but they can be moved by
means of a rod through a stuffing box.
Supposing the piston, according to Fig. 1, to be commencing its return stroke by
motion previously imparted to the fly wheel, air and gas are drawn in through
valves G and R into end S of cylinder A (the exhaust slide F being open), also up
the passage N into end T of piston B, expelling by the passage O through the
valve P (which opens into a recess in the bottom of cylinder A) into end U of main
cylinder A, the compressed charge of gas and air drawn by previous in stroke of
engine. The passage O can also be governed by a slide valve.
When the crank has turned the centre the charge is ignited by the slide a¹,
which contains a piece of metal which the jet flame w has been making hot
during the out and return stroke of engine. The heated metal keeping a small
quantity of gas alight, so that upon the slide a' uncovering the recess X, in plan
Fig. 2, to the compressed charge in cylinder, the same is ignited and causes the

page_text: main piston to make an outward movement. (This ignition can also be arranged
to take place at end Z) which causes the previous charge of gas and air in end S
of main cylinder, and end T of piston B passing by passage N to be driven through
valve Y into end Z of piston B, so that on the return stroke the compressed charge
is forced to end U of main cylinder and the motion continues. The action of
cylinder, Fig. 3, is precisely the same, and as the same letters are used on Drawing
the working can be understood by explanation of Fig. 1, and the igniting slide a¹
being placed on the inner side of cylinder and slide G, controlling the admission of
gas and air in place of ordinary valves G and R, Fig. 1, the exhaust valve F
being similarly placed on inner side of bottom of cylinder.
According to Fig. 4 we make the cylinder A open one end, so, that on the out-
stroke air is drawn through valve Y and gas through passage c into passage b, and
thence into interior of piston B, on the in stroke piston C compresses the charge
drawn in, until port d opens into passage e, which contains a valve, into the cylinder,
when the charge is allowed to escape to end U of cylinder A upon the outstroke
the slide a uncovers the communication to the heated metal and gas; when the
charge is ignited, and the piston completes its outstroke upon returning, the
products of combustion are exhausted through passage E, and F in slide; Fig. 5
shows a modification of this slide valve by making it a series of pistons; Fig. 6-
shows a long piston with ports arranged thereon; upon its out stroke gas and air
are drawn in through piston B at port a and valve b, the air port being just under
the gas port, the piston continues to move outwards and shuts off communication
with the gas and air, and opening the ignition port c which has a valve inside the
piston; this fires the charge and the out stroke continues; on nearing the end it
draws the slide valve F, which opens a passage d, and upon the piston returning
opens this into passage c on piston Fig. 7; this causes a communication with the
atmosphere for the emission of products of combustion; upon the piston nearing the
end of its instroke it closes the exhaust valve F.
Having thus described our said Invention, and the manner of performing the
same, we wish it understood that we claim,―
Firstly. The employment in gas motor engines of a piston within a piston, for
the purposes described.
Secondly. The employment in gas motor engines of a piston longer than its
stroke, for the purpose described.
Thirdly. Arranging the slide valve or valves, as described, within the cylinder
cover or casing of cylinder, for the purpose of keeping the valve tight and lessening
the friction.
Fourthly: Working internal slide valves of gas motor engines externally, as
described.
In witness whereof, we, the said George Gordon Picking and William Hopkins,
have hereunto set our hands and seals, this Fourth day of March, in the
year of our Lord One thousand eight hundred and eighty.