IMPROVEMENTS IN GAS MOTOR ENGINES
Year: 1883

page_text: LETTERS PATENT to George Gordon Picking and William Hopkins Engineers,
both of Bow in the County of Middlesex for an Invention of "IMPROVEMENTS
IN GAS MOTOR ENGINES
"
PROVISIONAL SPECIFICATION left by the said George Gordon Picking and
William Hopkins at the Office of the Commissioners of Patents on the
18th May 1883.
47
47
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 that class of Gas motor engines in
which the explosive mixture is in a state of compression before ignition and has
for its object, increasing the certainty of firing the mixture of gas and air in the
cylinder by the thorough cleansing of the firing chamber or cylinder each stroke
and previous to the introduction of the next charge of explosive mixture, and this
object is attained by passing through the cylinder or firing chamber a charge of
pure air previous to the next explosive charge being introduced, also to obtain
greater economy of gas with regularity of speed.
A charge of combustible mixture is introduced alternately to each end of the
cylinder the refuse of combustion escaping at or near the middle of the cylinder.
We prefer to make the piston longer than ordinary so that the exhaust or
discharge port although not governed by a valve is only uncovered at the right
time but if the exhaust port is governed by a valve worked from the engine, a
piston of ordinary length may be used
To obtain the introduction of the explosive mixture into the firing chambers wo
provide a pump preferably situated under the main cylinder, this pump is closed
both ends and fitted with a piston or plunger worked by means of a bell crank
lever from the crosshead of engine and a rod passing through a stuffing box in the
cover of the pump-The stroke of the pump is only half the stroke but makes
two strokes to one of the main piston and when the pump piston is moving
outwards it draws in through a suitable valve or valves air and gas and at the
[Price &dl

page_text: same time from the opposite side is discharging pure air (previously drawn in)
through the main firing chamber or cylinder. When the stroke of the pump is
reversed it compresses and discharges the combustible mixture into the firing
chamber or cylinder previously cleansed by the charge of pure air, and from the
opposite side of the piston is drawing in from the atmosphere a fresh charge of
pure air to cleanse the reverse end of the main firing chamber or cylinder.
The ends of the two firing chambers from each end of the cylinder are brought
together at the middle of the cylinder or may be turned at each end and the charge
is ignited to each end by a slide worked by an eccentric from the engine shaft and
moved so that it alternately ignites the charge in each firing chamber from one or
more external flames or the charge may be ignited by two sets of valves in a
chamber divided by a partition and the valves alternately raised from their seats
by an eccentric or cams worked from the engine shaft.

page_text: 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 17th November 1883.
GEORGE GORDON PICKING and WILLIAM HOPKINS both of Bow in the County
of Middlesex Engineers " IMPROVEMENTS IN GAS MOTOR ENGINES'
"
This Invention relates to Improvements in that class of gas motor engines in
which the explosive mixture is in a state of compression before ignition and has
for its object decreasing or preventing the liability to misfiring of the mixture of
gas and air in the cylinder by thoroughly expelling from the firing port and
cylinder the exploded contents and result of combustion each stroke, and previous
to the introduction of the next charge of explosive mixture and the object is
attained by passing through the firing port and cylinder (the exhaust being open
at the time) a quantity of air to cool and eleanse the cylinder previous to the next
explosive charge being introduced also to obtain greater economy of gas with
regularity of speed by giving the piston an impulse twice in each revolution a
charge of uniformly mixed gas and air being introduced alternately to each end of
the cylinder the refuse of combustion escaping at or near the middle of the
cylinder We prefer to make the piston longer than ordinary so that the exhaust
or discharge port although not governed by a valve is only uncovered at the right
time but if the exhaust port be governed by a valve worked from the engine a
piston of ordinary length may be used To obtain the introduction of the explosive
mixture into the firing port and cylinder we provide a pump preferably situated
under the main cylinder; this pump according to one arrangement is closed at both
ends and fitted with a piston or plunger This pump may be driven by gearing
from the engine shaft so that it makes two revolutions to one of the engine but
we prefer to work it by means of a bell crank lever from the cross head or from
an arm attached to the connecting rod at the cross head of the engine and by a
suitable rod passing through a stuffing box on the cover of the pump The stroke
of the pump is only about one half the stroke of the engine but by the arrange-
ment of the levers the plunger of the pump makes two strokes to one of the main
piston, when the pump piston is moving outward it draws in through a suitable
valve or valves air and gas together which by means of a perforated plate are
thoroughly mixed as drawn in and at the same time from the opposite end of the
pump is discharging the products of combustion from the main cylinder by means
of the cleansing or flushing charge of air.
When the stroke of the plunger in the pump is reversed it slightly compresses
and discharges the thoroughly mixed firing mixture (previously drawn) into the
firing port and cylinder which is now empty and the pump piston from the opposite
end is drawing in a fresh charge from the atmosphere to cleanse the reverse end
of the main firing port and cylinder The ends of the two firing ports from each
end of the cylinder are brought together at the middle of the cylinder (or they
may be turned at each end of the cylinder instead) and the charge is ignited at
each end by a slide worked from the engine shaft and moved so that it alternately
ignites the charge in each firing port from one or more external flames The slide
arranged with either one or two firing ports in it, when only one port is
used it can be arranged to ignite each end alternately or if two ports are made in
the slide one is used for igniting one end only and the other port for igniting the
reverse end only And in order that our Invention may be fully understood we
shall now more particularly describe the same and for that purpose shall refer to

page_text: the several figures on the annexed sheets of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 Sheet 1-Is a plan of a gas motor engine constructed according to our
Invention Figure 2 is a section of a modification of the slide valve-Figure 3 Sheet 2
is an elevation of the engine with the valve chamber partly in section-Figure 4
Sheet 3 is an end view of the engine Figure 5 Sheet 2 is a view of the end of the
pump in section shewing the tappet for regulating the gas supply-Figures 6. 7. and 8
are views of the discharge ports when governed by a valve for allowing the escape of
air from the cylinder. Referring to Figure 1 A is the cylinder of the engine (which
may be surrounded by a water jacket as usual) in which cylinder the pressure
resulting from the firing of the explosive charge imparts motion to the piston B
fitted in the said cylinder and connected by the rod C with the crank of the crank
shaft D mounted in bearings in the bed E of the engine and carrying fly wheels F
under the cylinder A. In the bed E of engine is formed or carried a pump
cylinder G in which works a plunger or piston H moved by a rod I and connecting
rod J from a bell crank lever K fitted inside the bed of engine E and vibrates upon
a fixed centre pin K The connecting rod L of engine has at the crosshead end
extending down into the bed an arm L* to which one arm of the bell crank lever K
is connected by a rod M. so that by the instroke of the main piston B the pump
piston or plunger H is caused to make a complete in and outstroke and upon the
main piston B making an outstroke the pump piston or plunger H is caused to
make another complete in and out stroke so that the pump piston H makes two
strokes to one of the main piston B which enables a charge of explosive mixture
to be supplied to each port alternately in a double acting gas motor engine without
the employment of two pumps and also it is much more economical as no explosive
mixture is wasted. It will be evident however that two pumps may be employed
if desired The reverse end of the pump G¹ is used at pleasure to store up a supply
of air to alternately flush out the main cylinder A or the use of this end may be
dispensed with the plunger only being used to introduce the firing mixture to the
ports of the cylinder
The gas supply is taken from the pipe O through a valve P the opening of
which valve is regulated by means of the governor through the rod R at the end
of the bed which form the cover of the pump and projecting into the pump is a
small tappet S which the plunger or piston H of the pump pushes out every stroke
The tappet S is attached to one end of the lever T and this lever rocking at the
fulcrum U presses in the gas regulating valve P every stroke just as the pump G
is about to be filled with explosive mixture. If the governor balls be raised by
reason of the engine running too fast the spindle R is pushed down and holds the
catch V in, which prevents the gas valve P opening until the pump makes another
stroke when if the governor balls have fallen the catch V is released and the gas
valve P opens full-The gas supply being taken through the pipe O as the pump
piston recedes from the outer end of the pump, air is drawn through the air
regulator W raising the two valves X and at the same time inflammable gas or
vapour is drawn in through the small holes Y and past the perforated deflecting
plate Z which intimately and thoroughly mixes the gas with the entering air so
that a perfectly homogeneous mixture enters the pump at this end through the
passage A at the other end G¹ of the pump air (previously drawn in through the
valve B') is being discharged into one of the firing ports or chambers and passing
through all the holes C C C C C perfectly flushes the cylinder A, as soon
as the motion of the pump piston H is reversed the firing mixture is discharged
through the same firing port and through the holes C C C C C and
driving any air left in the cylinder out at the ports 2 2¹ from whence it is
conducted by the pipe to the air chamber 4 so that whatever firing mixture
escapes with the air it is drawn into the pump by the next stroke and there
remains a thoroughly uniform mixture in the cylinder A upon the return of the
main piston B the mixture is compressed and driven back through the holes or
ports CCC CC into the firing ports or chambers N N so that the

page_text: greatest possible diffusion and equal mixture of the gas and air exists in the
cylinder the mixture when compressed is fired and this operation is repeated at
the opposite end and the motion continues.
To make sure that the firing mixture shall be directed to the proper firing port
N N¹ we prefer to put a plug D' in the casing E' and oscillate it by means of an
eccentric or cam from the engine shaft D but this plug or slide D¹ may be dispensed
with as the pressure in the one port will hold the valve down while the other is
free to rise.
1
The arrangement for ignition is as follows-The slide F¹ is worked direct from
an eccentric on the shaft thus avoiding complication of joints There may be only
one ignition port H¹ in the slide (this having inserted in it if desired a small piece
of platinum wire) which serves by the motion of the slide F¹ to ignite the mixture in
each of the cylinder firing ports N N₁ alternately. The slide F¹ being in the position
shown in Figure 1 The ignition port H₁ has by the movement of the slide F¹
come opposite the firing port N in the slide face upon the return movement of the
slide F a small passage I¹ has come opposite the firing port N¹ in the slide face
which allows the pressure in the firing port N¹ to cleanse the ignition port H¹ and
at the same time heat the platinum wire in the port this port being cleansed the
movement of the slide F¹ continues and the small quantity of firing mixture
contained in the port H¹ is lighted from the constant burning gas flame J' and the
heated platinum wire in the port The slide moves still further and the ignition
port comes opposite the other firing port N¹ in the slide face and ignites the charge
at this end thus an explosion takes place twice in every revolution (first on one
side of the piston and then on the other) making the engine double acting and by
this means the speed is rendered very regular-The slide instead of having only
one ignition port H' may have two H¹ H¹ as in figure 2 each in its turn serving
to ignite the firing ports N N¹ as described.
Any form of governor may be used the one Q shown is driven by a gut or strap
from a pulley on the engine shaft and acts direct on the catch V for stopping the
supply of gas when the engine is running too fast
Having now described and particularly ascertained the nature of our said
Invention and the manner in which the same is or may be used or carried into-
effect we would observe that what we consider to be novel and original and
therefore claim as the Invention secured to us by the hereinbefore in part recited
Letters Patent is
First the arrangement and combination of parts constituting the improved Gas
Motor Engine substantially as herein before described and represented in the
accompanying drawings.
Second The arrangement of firing ports or chambers N N¹ as applied to double
acting gas motor engines in which the charge is compressed before ignition whereby
the said ports or chambers are brought near to the middle of the cylinder
substantially as hereinbefore described.
Third In double acting gas motor engines in which the charge of air and gas is
compressed before ignition the arrangement of a slide for igniting the charge in
both firing ports alternately whereby one slide can be used for both ports
substantially as hereinbefore described.
Fourth In double acting gas motor engines in which the charge of gas and air
is compressed before ignition the use of a piston to act as a valve in combination
with a central exhaust substantially as and for the purpose hereinbefore described.
Fifth In gas motor engines the arrangement of bell crank lever mechanism for
working a pump substantially and in the manner and for the purpose herein before
described.
Sixth, In gas motor engines the use of holes or ports C¹ C
situated between the firing ports N N¹ and the main cylinder A substantially as
and for the purpose hereinbefore described.
Seventh. In double acting gas motor engines the arrangement whereby one

page_text: pump is utilized to serve the charge of air and gas to both ends of the main
cylinder substantially as hereinbefore described, and
Eighth. The means whereby whatever air remaining in the cylinder (previous
to the introduction of the explosive mixture) is driven out of the cylinder by the
incoming explosive mixture and conducted to the air inlet of the pump so that
whatever explosive mixture escapes with the air it is drawn into the pump and
used for the next stroke substantially as and for the purpose hereinbefore
described.
In witness whereof we the said George Gordon Picking and William Hopkins
have hereunto set our hands and seals this seventeenth day of November in the
year of Our Lord One thousand eight hundred and eighty three
GEORGE GORDON PICKING (L.S.)