IMPROVEMENTS IN GAS MOTOR ENGINES
Year: 1878

page_text: LETTERS PATENT to Richard Hallewell, of Blackburn, in the County of
"
Lancaster, Engineer, for the Invention of IMPROVEMENTS IN GAS MOTOR
ENGINES."
aled the 6th June 1879, and dated the 12th December 1878.
PROVISIONAL SPECIFICATION left by the said Richard Hallewell at the
Office of the Commissioners of Patents on the 12th December 1878. .
RICHARD HALLEWELL, of Blackburn, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN GAS MOTOR ENGINES."
My Invention relates, in the first place, principally to improvements in the first
part of a former Invention, for which Letters Patent bearing date the Twenty third
day of December, in the year One thousand eight hundred and seventy six, and
numbered 4987, have been granted to me. In the said former Invention I caused
the gas entering the cylinder of a gas-engine to flow in divided currents through
the perforations of a plate for the purpose of promoting a more gradual combustion
of the gas. The object of the first part of my present Invention is to increase the
power of the engine relatively to its proportions. In the first arrangement I extend
the acting end of the cylinder to form an explosion or expansion chamber, and I
arrange for the explosion to occur at every alternate stroke of the piston in the
same direction. During the intermediate strokes the piston draws in air, which,
together with any remaining products of combustion, is compressed by the return
stroke into the explosion chamber. The gas is then forced by means of a gas-pump
through the perforated plate into this high pressure air, and the explosion takes
place to produce the acting stroke. I prefer to actuate the gas-pump by means of
a cam, which effects a preparatory compression of the gas and then quickly forces
it into the cylinder. In a modification, I employ a separate air-pump to compress
the air and to force it into the cylinder, in which case the explosions may take
place more frequently than at every alternate acting stroke; or I make the engine
double-acting by arranging for the explosions to take place alternately at each end

page_text: of the cylinder. In another arrangement, I employ an expansion or explosion
chamber which can be shut-off from the cylinder by means of a valve, and I arrange
for the air which is in the cylinder on the opposite side of the piston to that upon
which the explosion or combustion takes effect to be compressed by the acting
stroke and be conveyed into the said expansion chamber. Preparatory to the
explosion the said valve is moved to close the compressed air inlet and to admit the
compressed air into the end of the cylinder in which the acting force is exerted, I
may employ two expansion chambers. To govern the engine I cause the governor
to open a valve for the escape of the air when required and at the same time to
disengage a clutch so as to arrest the movement of a shaft which actuates the gas-
pump, and the slide valves or the piston of the gas-pump may continue in motion,
the governor acting to shut-off the gas supply and to open an air valve. To render
the firing of the gases under pressure more certain, I form the firing valve with
two ports, which, when the firing is to take place, communicate with two corre-
sponding ports leading into the cylinder or expansion chamber, or I'may fire by
means of electricity generated by a dynamo-electric machine actuated by the engine,
or otherwise generated. In any of the cases the said perforated plate may be flat,
or dished, or partly globular, or a hollow perforated body may take its place. A
second part of my Invention consists of improvements in the second part of my said
former Invention. I connect the air-engine cylinder with the other two cylinders
in such a manner as that it's inner end opens directly into the inner end of the air
compressing cylinder. In one arrangement, the air-engine cylinder is at right-
angles with the other two cylinders. I may form all three cylinders in one casting.
When the main piston is forced outwards by the explosion, the compressing piston
draws air in through an inlet valve. At the return stroke the said valve closes
and the air is compressed and acts on the air-engine piston. To permit the air-engine
piston to reciprocate in the intervals between the explosions, I arrange for the said
inlet valve to be opened at a suitable point in the inward stroke of the said piston,
and to govern the engine I arrange for the governor at the required times to pre-
vent the said opening of the inlet valve, or to close an outlet valve, whereby the
air-engine piston compresses the air, and the pressure thus arising raises the air-
compressing piston and thereby the main piston, whereby an explosive charge is
drawn in and an explosion takes place. In a modification, I cause the main piston
to compress a charge of air which is delivered by the outward stroke of the said
piston into the air compressing cylinder, so that there is a pressure of air within
such cylinder at the commencement of the return stroke of the two pistons. My
Invention relates in the third place to parts of an Invention for which Letters
Patent bearing date the Fourth day of May in the present year have been granted
to me. I mount the gripping lever, described in the first part of my said Invention,
upon a plate which is secured to an extension of a portion of the outer end of the
cylinder, whereby the cylinder cover is dispensed with, and the piston can be with-
drawn when the said plate has been detached and removed. I also connect the
said lever with a slide-valve, which I employ in lieu of the ordinary flap-valve, and
which opens and closes a passage leading from the exhaust port, and permits the
gases to escape during the descent of the loose piston, the said lever opening and
closing the said valve at the required times.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard Hallewell in the Great Scal Patent Office on the 12th June
1879.
RICHARD HALLEWELL, of Blackburn, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN GAS ENGINES."
My Invention relates principally or partly to improvements in the first part of a
former Invention, for which Letters Patent bearing date the Twenty third day of
December in the year One thousand eight hundred and seventy six, and numbered
4987, have been granted to me. In the said former Invention I caused the gas
entering the cylinder of a gas engine to flow in divided currents through the
perforations of a plate, for the purpose of promoting a more gradual combustion of
the gas. The object of my present Invention is to increase the power of the engine
relatively to its proportions. In the first arrangement I extend the acting end of
the cylinder to forni an explosion or expansion chamber, and I arrange for the
explosion to occur at every alternate stroke of the piston in the same direction.
During the intermediate strokes the piston draws in air, which, together with any
remaining products of combustion, is compressed by the return stroke into the
explosion chamber. The gas is then forced by means of a gas pump through the
perforated plate into this high pressure air, and the explosion takes place to produce
the acting stroke. I prefer to actuate the gas pump by means of a cam which
effects a preparatory compression of the gas and then quickly forces it into the
cylinder. Modifications may be made in the arrangement, as will be hereinafter
indicated. To govern the engine I cause the governor to open air valves when
required. I form the firing valve with two ports which, when the firing is to take
place, communicate with two corresponding ports leading into the cylinder or
expansion chamber. In any of the cases the said perforated plate may be flat, or
dished, or partly globular, or a hollow perforated body may take its place.
And in order that my Invention may be fully understood, I have appended here-
unto a Sheet of Drawings made to a scale of about three inches to the foot, and.
marked with letters of reference, to which Drawings I will now refer. Fig. 1
represents a side elevation; and Fig. 2, a vertical section of so much of a gas
engine constructed in accordance with my Invention as is necessary to the illustra-
tion of the said Invention. In the said Figures, A is a cylinder, in which works a
piston B which is connected by the rod C with the crank shaft D. At the upper
end of the said cylinder is an explosion chamber E, which is formed by extending
the upper end of the said cylinder. Upon the top of this extension is secured a
head F, in which are formed gas and air passages, and in and upon which the slide
valve works. A plan of this head is represented by Fig. 3, and a second section by
Fig. 4. To the underside of the head is secured a gas pump G in which works a
piston, to which is secured a piston rod h. Upon the lower end of the said piston
rod is mounted a bowl, upou which a cam i acts. The said cam is secured upon a
second motion shaft j which receives motion through gearing from the crank-
shaft. The said gearing is so proportioned as that the shaft ; makes one revolution
j
to cach two revolutions of the crank shaft. In the head F are formed two gas ports
and m,
and the latter is connected with the gas supply-pipe n.
from the said supply pipe to the port m through a self closing
arranged to be opened by the exhausting action of the gas pump.
the slide valve P establishes a communication between the ports
times when the pump has to draw-in gas, as indicated in Fig. 4.
valve is provided with a bowl, upon which acts a cam q which is fixed upon a
shaft r which is connected by bevil-gearing with the shaft j.. During each revolu-
tion of the said shaft the said slide valve is caused to slide to and fro. When the
said slide valve is in the position indicated in Fig. 1, the cavity o establishes a
The gas passes
valve which is
A cavity o in
and m at the
The said slide

page_text: communication between the port and a passages which is formed in the head F,
and opens into a hollow perforated body T which answers the purpose of the afore-
said perforated plate. In the slide valve is formed a firing chamber u which is
formed with two ports opening towards the explosion chamber instead of with one
as is usual. In the head F are formed two corresponding ports v, v, which open
into the explosion chamber. A cavity w serves to maintain a communication
between a passage leading to a relighting gas-jet x and a gas supply passage, and
other passages y, y, serve to supply the firing jet with air. In the head F is formed
an air-inlet passage which is provided with a self-closing valve which opens
inwardly. The said head is also formed with an exhaust passage which is fitted
with a valve a' which is provided with a spindle, upon which a spring acts to close
the said valve. A lever bis mounted upon a fulcrum and is acted upon by a
cam which is fixed upon the shaft r. Once during each revolution of the said
shaft the said cam depresses one end of the said lever, whereby the other end of the
said lever is raised, and coming into contact with the lower end of the spindle of
the valve a pushes open the said valve. The actions of the parts are so adjusted
as that the opening of the said valve takes place at about the commencement of
each alternate return or inward stroke of the piston, whereby the products of
combustion are permitted to escape. The lever is also arranged to be acted
upon by the sleeve of a governor which receives motion from the crank-shaft.
The said governor is so arranged and adjusted as that when the engine exceeds its
normal speed the sleeve of the governor raises the end of the lever b¹, whereby the
valve a is opened. At the same time the said lever, when so. acted upon by the
governor, acts upon the spindle f¹ of a valve, which is indicated at g' in Fig. 3 and
by dotted lines in Fig. 1. The said spindle is formed with a slot, in which works a
stud which is fixed to the lever b'. During the ordinary action of the said lever,
as derived from the cam c¹, the said stud does not quite reach the bottom of the
said slot, but when the said lever is acted upon by the governor as aforesaid the
said stud reaches the bottom of the slot, and by drawing down the spindle opens
the valve and thereby admits air to the gas-pump. The action of the engine may
be described as follows:--I will suppose the piston B to have reached the termina-
tion of an inward stroke, during the whole or part of which the valve a' has been
open to expel the products of combustion. The piston now makes an outward
stroke, and the valve opens self actingly and admits air to the cylinder and
chamber E. During this time the pump G has been drawing in a supply of gas.
The piston now makes an inward stroke, and the valve z closes so that the im-
prisoned air is compressed into the chamber E. The piston of the gas pump is at
the same time compressing the charge of gas which it has drawn in, and the slide
valve has been moving into the position indicated in Fig. 1. Towards the end of
the said inward stroke of the piston, or at the commencement of the next outward
stroke, or within these limits, the slide valve establishes the communication for the
flow of gas from the pump G to the perforated body T, and the compressed gas
issues through the perforations of the said body in fine streams into the body of
compressed air in the chamber E. The slide valve now makes a quick movement
towards the cam q, whereby the two ports of the firing chamber are brought opposite
the two ports v, whereby the gases in the chamber E are fired, and the piston now
makes it's outward stroke. The two ports v and the two firing ports in the slide
valve make the firing of the gases more certain. When the piston commences its
next outward stroke the cam c¹ acts upon the lever b¹ to open the exhaust valve a',
as aforesaid, and the excess of gases in the cylinder and explosion chamber are
permitted to escape. At the next outward stroke the valve z opens to admit air as
aforesaid, and the operations are repeated, the explosion taking effect at each
alternate stroke of the piston. When the engine exceeds it's normal speed the
governor acts upon the lever b¹ as aforesaid, and the air valve g¹ is opened, whereby
air is admitted to the gas-pump. This admission of air by decreasing the exhaus-
tive action of the pump prevents the gas-inlet valve from opening, so that as long
as the valve g¹ remains open gas is not delivered to the explosion chamber and the

page_text: speed of the engine becomes thereby reduced, the opening of the valve a³ preventing
the compression of air in the explosion chamber. The form of the perforated
body T may be greatly varied. In Fig. 1 it consists of a hollow disc joined to a
tube. A modification in the form of this part is indicated in Fig. 5. The per-
forated plate referred to in my aforesaid former Specification may be substituted
for the said perforated body. Other modifications may also be made without
departing from the nature and intent of my Invention, as for example, a special
pump may be employed to compress air into the chamber E instead of compressing
the air by means of the engine piston, in which case the explosions may take place
at each stroke of the engine. The engine may be made double-acting by arranging
for the air to be compressed alternately into each end of the cylinder or into
explosion chambers at each end of the cylinder, the explosions taking place at each
end of the cylinder alternately, or the air may be compressed by the front side of
the piston during the outward stroke and be admitted through a valve into the
explosion chamber, which is shut-off from the cylinder by means of a grid-iron
valve or of a suitable valve, which is opened at or about the time when the explo-
sion takes place. I would remark that the term compressed air used herein is
meant to include a non-explosive mixture of gases. In my Provisional Specification
I divided my Invention into three parts, but I have not included herein the second
and third parts of the Invention referred to in the said Specification, and I
therefore make no claim herein in respect of such second and third parts, but I
claim,―
- First. The gas engine constructed and acting substantially as set forth and
indicated herein-before and in and by the accompanying Drawings.
Secondly. Providing gas engines with explosion chambers, in which air is com-
pressed, and forcing the charge of gas into such compressed air previous to the
explosion, substantially as set forth and indicated.
Thirdly. Injecting gas by means of a pump through a perforated plate or through
a hollow perforated body into a body compressed air, substantially as and for the
purpose set-forth and indicated.
Fourthly. Regulating the speed of a gas-engine by arranging for the governor to
open inlet valves admitting air to the cylinder and the gas injecting pump.
Sixthly. The double firing ports, substantially as set forth and indicated.
And, lastly. The hollow perforated body, substantially as and for the purpose set
forth and indicated.
In witness whereof, I, the said Richard Hallewell, have hereunto set my hand
and seal, this Eleventh day of June, in the year of our Lord One thousand
eight hundred and seventy nine
Signed and sealed by the
said Richard Hallewell
in the presence of
EDWARD K. DUTTON,
Agent to the Patentee,
St. Anus Churchyard,
Manchester.
RICHARD HALLEWELL. (L.S.)