Improvements in Gas Engines.
Year: 1891

page_text: Date of Application, 10th June, 1891
Complete Specification Left, 7th Apr., 1892-Accepted, 4th June, 1892
.
PROVISIONAL SPECIFICATION.
Improvements in Gas Engines.
1, HENRY THOMAS DAWSON of Salcombe in the County of Devon, Gentleman,
do hereby declare the nature of this invention to be as follows:-
This invention has for its object improvements in gas engines and relates more
especially to gas engines in which the piston serves as the valve to admit the
gaseous charge to the cylinder, to bring the same into communication with igniting
apparatus and to allow of the escape of the products of combustion, each at the
appropriate time as is described in the Specification of a Patent granted to me
No. 6407 in the year 1890. The first improvement is in the way in which the
necessary continuous rotary motion of the piston within the cylinder is obtained.
This is effected by means of the connecting rod and parts in connection therewith.
One part of the connecting rod is fitted at one end with the bearing which receives
the crank pin and at its other end there is a collar in which an axis forming another
part of the connecting rod is able to rotate. This axis is at one end coupled by a
ball and socket joint with the piston and at the other end it is held in a bearing
formed in connection with the main or crank pin bearing. The crank pin has a
worm or oblique teeth upon it and these teeth are in gear with a wheel with
corresponding teeth upon the axis. The axis thus rotates in the collar and bearing
as the crank revolves. Near to the ball joint which connects the axis with the
piston, the axis has horns clipped upon it and these project on either side. The
horns serve to transmit the rotary motion of the axis to the piston. A semicircular
yoke piece is jointed to the piston with pivots at right angles to the axis of the
cylinder in this yoke piece are slots into which the horns are received.
Sometimes in place of the ball and socket joint I connect the piston with the axis
by means of a cross piece. Two opposite arms of the cross piece are held in
bearings formed on the piston and the other two arms are held in bearings formed
at the extremity of the axis; thus an universal joint is formed which admits of
freedom to rock in any direction through a sufficient angle but compels the piston
to rotate with the axis. The gear wheel at the further end of the axis I secure by
clips which admit of its accurate adjustment so that the ports may come together at
the proper times. There are worm teeth upon the axis and one of the clip bolts is
threaded to engage with the teeth. When driving horns are employed as previously
described their accurate adjustment is provided for in a similar manner.
The gear
is arranged in accordance with the cycle of the engine, it may be so that the piston
rotates once for two revolutions of the crank shaft; or sometimes once for three or
four or other number of revolutions of the crank shaft. In large engines I
duplicate the ports and revolve the piston at half the speed which otherwise would.
be required.
Sometimes I provide for the rotation of the piston by gearing independent of the
connecting rod. The piston is provided with a trunk and around the trunk is a
ring engaging with it with grooves and feathers. The ring is held in a recess
provided for it in the frame and it has teeth around its periphery. A pinion
engages with the teeth and on the same axis with the pinion there is a bevilled
wheel engaging with another similar wheel upon the crank shaft.
The axis may be extended to work a pump or to drive a governor.
My invention also relates to the construction of the piston and parts in connection
therewith. The piston I form hollow, it is filled with asbestos to lessen the con-
duction of heat and it is surrounded by a ring which is fitted to the cylinder, it may
be by the aid of spring packing rings around it. The piston ring is confined

page_text: between flanges or cover plates on the piston which allow it some freedom in a
radial direction.
The piston is provided with trunks both on its upper and under sides. The
trunks have inwardly directed flanges and by these they are connected with the
piston but so as to allow a certain amount of freedom as in the case of the piston
ring. The piston ring and the trunks are further connected with the piston so that
all the parts rotate together.
The lubrication of the piston is obtained in the following way :-The crank
revolves in a chamber containing oil or oil and water and the trunk on the under
side of the piston is open to this chamber; consequently when the engine is at work
the trunk is filled with a spray of the lubricating material. Perforations are made
in the trunk and these allow the lubricant to pass in sufficient quantity to the inner
walls of the cylinder.
Screen plates are provided within the crank chamber and these aid in directing
the spray into the trunk.
There is an air pipe in connection with the crank chamber and in connection
with this is a collecting box in which oil carried out of the chamber by the air is
deposited and it drains back into the crank chamber.
Another part of my invention relates to the regulation of the gaseous charge. I
régulate the admission of gas by a governor consisting of an axis driven in any
suitable manner from the crank shaft of the engine. Upon the axis there is a
collar and at a distance from the collar there is a slider and these are connected
the one with the other by rule jointed links. At the joints of the links are the
weights or balls of the governor. The rotation of the axis tends to throw the
weights outwards and to draw the slider along the axis towards the collar. This
action is resisted by a coiled spring around the axis which controls the movement
of the slider. The slider is connected with a rod contained within the axis and
imparts to it a longitudinal movement. The governor axis is geared with another
axis which rotates once in the cycle of the engine and upon this axis there is a
sleeve sliding with groove and feather and it has several cams upon it either of
which by the movement of the sleeve can be brought into position to operate upon
the gas valve through an interposed lever.
The sleeve has also right and left threads or worms upon it. In front of the
sleeve is a form lever which rocks on an axis at the centre of its head and on
the two sides of the head there are teeth. The rod moved by the governor is
jointed to the stem of the T lever and the movement of the stem brings the teeth
upon the lever into gear with one or other of the worms. The sleeve then slides
along its axis and shifts the cams as may be required.
According to another arrangement I provide but one cam upon the sleeve and
this is brought by the governor into position to operate on the gas valve when a
charge is to be admitted to the cylinder. When the governor balls diverge they
impart longitudinal motion to a rod as already described this rod however in place
of being connected with the T lever gives motion to a sleeve on the governor axis.
This sleeve has cams at its ends and one or other of these operates to move a
T lever mounted on a fixed fulcrum and this lever in turn actuates the first
mentioned sleeve or that carrying the cam for operating the gas valve:
Another part of my invention relates to the ignition of the gaseous charge. The
ignition of the charge is effected by allowing a portion of it to enter a capsule
enclosed in a furnace within which by a flame playing upon the exterior of the
capsule it is maintained at a high temperature. I use a short porcelain tube open
at both ends. One end of the tube fits to a seat at the ignition port in the cylinder
and the other fits to and is closed by a block, it may be of metal, which is pressed
up to the tube by a spring, the pressure of which serves to hold the tube in place.
Ignition capsules thus fitted are not liable to break by unequal expansion in heating
and in case of fracture they are easily replaced.
A capsule closed at its end may be employed in a like manner being held up to a
scat by a spring. Métal tubes and capsules may be similarly arranged. The flame

page_text: which heats the capsule may be an ordinary Bunsen burner or may be urged by an
air blast. In the latter case the air is drawn from a reservoir into which it. is
compressed by an air pump worked by the engine or at starting actuated by hand
until the necessary pressure is obtained. The piston of the air pump is connected
with a slide which can be traversed along a lever. An eccentric imparts a rocking
motion to a disc turning it to and fro through a certain angle. The lever and disc
can be clutched together and the engine then works the pump, giving a longer or
shorter throw to the piston according to the position in which the slide has been
placed. In this way the quantity of air passed into the reservoir can be varied.
For working the pump by hand the lever is unclutched from the disc.
Great uniformity in the pressure of the air in the reservoir is desirable; this is
obtained by connecting the reservoir by a pipe with a water cistern raised some
distance above the air reservoir. The air forced in displaces the water from the
reservoir and any excess of air, and the pump should be so adjusted as to provide a
small excess which excess escapes by the pipe and rising through the water in the
cistern, passes away.
In some cases I provide the air pump with two pistons one of which receives
movement by means of an eccentric from the engine. When I rotate the main
piston by external gear I place the eccentric on the gear shaft provided for this
purpose. The other piston of the air pump I connect with a lever by which it can
be worked by hand when required on starting the engine. This second piston at
other times is locked in position and then it forms in effect the end of the air pump
cylinder. The quantity of air delivered by the pump can be varied by shifting
the position of the second piston so as to alter the amount of clearance between
the two.
Another method of ignition which in some cases I employ consists in providing a
small ignition chamber which at the proper time is placed in connection with the
cylinder. The ignition chamber also communicates with a chimney but a valve
worked by a cam or otherwise closes the passage whilst the ignition chamber is
open to the cylinder. A jet of mixed gas and air compressed by a pump or
otherwise is driven into the ignition chamber. The jet is ignited by a flame in the
chimney just outside the valve. The valve closes at the proper time and then
when the communication with the cylinder is permitted the flame is carried from
the ignition chamber into the cylinder.
Dated this 10th day of June 1801
CARPMAEL & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Gas Engines.
1, HENRY THOMAS DAWSON of Salcombe in the County of Devon, Gentleman,
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement :-
This invention has for its object improvements in gas engines and relates more
especially to gas engines in which the piston serves as the valve to admit the
gaseous charge to the cylinder, to bring the same into communication with igniting
apparatus and to allow of the escape of the products of combustion, each at the
appropriate time as is described in the Specification of a Patent granted to me
No. 6407 in the year 1890. The first improvement is in the way in which the
necessary continuous rotary motion of the piston within the cylinder is obtained.
This is effected by means of the connecting rod and parts in connection therewith.
One part of the connecting rod is fitted at one end with the bearing which receives
the crank pin and at its other end there is a collar in which an axis forming another
part of the connecting rod is able to rotate. This axis is at one end coupled by

page_text: a ball and socket joint with the piston and at the other end it is held in a bearing
formed in connection with the main or crank pin bearing. The crank pin has a
worm or oblique teeth upon it and these teeth are in gear with a wheel with corre-
sponding teeth upon the axis. The axis thus rotates in the collar and bearing as
the crank revolves. Near to the ball joint which connects the axis with the piston,
the axis has horns clipped upon it and these project on either side. The horns
serve to transmit the rotary motion of the axis to the piston. A semicircular yoke
piece is jointed to the piston with pivots at right angles to the axis of the cylinder;
in this yoke piece are slots into which the horns are received.
t
Sometimes in place of the ball and socket joint I connect the piston with the
axis by means of a cross piece. Two opposite arms of the cross piece are held in
bearings formed on the piston and the other two arms are held in bearings formed
at the extremity of the axis; thus an universal joint is formed which admits of
freedom to rock in any direction through a sufficient angle but compels the piston
to rotate with the axis. The gear wheel at the further end of the axis I secure
by clips which admit of its accurate adjustment so that the ports may come together
at the proper times. There are worm teeth upon the axis and one of the clip bolts
is threaded to engage with the teeth. When driving horns are employed as pre-
viously described their accurate adjustment is provided for in a similar manner.
The gear is arranged in accordance with the cycle of the engine, it may be so that
the piston rotates once for two revolutions of the crank shaft; or sometimes once
for three or four or other number of revolutions of the crank shaft. In large
engines I duplicate the ports and revolve the piston at half the speed which other-
wise would be required.
Sometimes provide for the rotation of the piston by gearing independent of
the connecting rod. The piston is provided with a trunk and around the trunk is
a ring engaging with it with grooves and feathers. The ring is held in a recess
provided for it in the frame and it has teeth around its periphery. A pinion
engages with the teeth and on the same axis with the pinion there is a bevilled
wheel engaging with another similar wheel upon the crank shaft.
The axis may be extended to work a pump or to drive a governor.
My invention also relates to the construction of the piston and parts in con-
nection therewith. The piston I form hollow, it is filled with asbestos to lessen
the conduction of heat and it is surrounded by a ring which is fitted to the cylinder,
it may be by the aid of spring packing rings around it. The piston ring is con-
fined between flanges or cover plates on the piston which allow it some freedom in
a radial direction.
The piston is provided with trunks both on its upper and under sides. The
trunks have inwardly directed flanges and by these they are connected with the
piston but so as to allow a certain amount of freedom as in the case of the piston
ring. The piston ring and the trunks are further connected with the piston so that
all the parts rotate together.
The lubrication of the piston is obtained in the following way:-The crank
revolves in a chamber containing oil or oil and water and the trunk on the
under side of the piston is open to this chamber: consequently. when the engine
is at work the lubricant passes in sufficient quantity to the inner walls of the
cylinder.
There is an air pipe in connection with the crank chamber and in connection
with this is a collecting box in which oil carried out of the chamber by the air is
deposited and it drains back into the crank chamber.
Another part of my invention relates to the regulation of the gaseous charge.
I regulate the admission of gas by a governor consisting of an axis driven in any
suitable manner from the crank shaft of the engine. Upon the axis there is a
collar and at a distance from the collar there is a slider and these are connected
the one with the other by rule jointed links. At the joints of the links are the i
weights or balls of the governor. The rotation of the axis tends to throw the
weights outwards and to draw the slider along the axis towards the collar. This

page_text: action is resisted by a coiled spring around the axis which controls the movement
of the slider. The slider is connected with a rod contained within the axis and
imparts to it a longitudinal movement. The governor axis is geared with another
axis which rotates once in the cycle of the engine and upon this axis there is a
sleeve sliding with groove and feather and it has several cams upon it either of
which by the movement of the sleeve can be brought into position to operate upon
the gas valve through an interposed lever.
The sleeve has also right and left threads or worms upon it. In front of the
sleeve is a T form lever which rocks on an axis at the centre of its head and on
the two sides of the head there are teeth. The rod moved by the governor is
jointed to the stem of the T lever and the movement of the stem brings the teeth
upon the lever into gear with one or other of the worms. The sleeve then slides
along its axis and shifts the cams as may be required.
According to another arrangement I provide but one cam upon the sleeve and
this is brought by the governor into position to operate on the gas valve when a
charge is to be admitted to the cylinder. When the governor balls diverge they
impart longitudinal motion to a rod as already described this rod however in place of
being connected with the T lever gives motion to a sleeve on the governor axis. This
sleeve has cams at its ends and one or other of these operates to move a T lever
mounted on a fixed fulcrum and this lever in turn actuates the first mentioned sleeve
or that carrying the cam for operating the gas valve.
Another part of my invention relates to the ignition of the gaseous charge. The
ignition of the charge is effected by allowing a portion of it to enter a capsule
enclosed in a furnace within which by a flame playing upon the exterior of the
capsule it is maintained at a high temperature. I use a short porcelain tube open
at both ends. One end of the tube fits to a seat at the ignition port in the cylinder
and the other fits to and is closed by a block, it may be of metal, which is pressed
up to the tube by a spring, the pressure of which serves to hold the tube in place.
Ignition capsules thus fitted are less liable to break by unequal expansion in
heating, and in case of fracture they are easily replaced.
A capsule closed at its end may be employed in a like manner being held up to
a seat by a spring. Metal tubes and capsules may be similarly arranged. The
flame which heats the capsule may be an ordinary Bunsen burner or may be urged
by an air blast. In the latter case the air is drawn from a reservoir into which it
is compressed by an air pump worked by the engine or at starting actuated by
hand until the necessary pressure is obtained. The piston of the air pump is con-
nected with a slide which can be traversed along a lever. An eccentric imparts a
rocking motion to a disc turning it to and fro through a certain angle. The lever
and disc can be clutched together and the engine then works the pump, giving a
longer or shorter throw to the piston according to the position in which the slide
has been placed. In this way the quantity of air passed into the reservoir can be
varied. For working the pump by hand the lever is unclutched from the disc.
Great uniformity in the pressure of the air in the reservoir is desirable; this is
obtained by connecting the reservoir by a pipe with a water cistern raised some
distance above the air reservoir. The air forced in displaces the water from the
reservoir and any excess of air, and the pump should be so adjusted as to provide
a small excess which excess escapes by the pipe and rising through the water in
the cistern, passes away.
In some cases I provide the air pump with two pistons one of which receives
movement by means of an eccentric from the engine. When I rotate the main
piston by external gear I place the eccentric on the gear shaft provided for this
purpose. The other piston of the air pump I connect with a lever by which it
can be worked by hand when required on starting the engine. This second piston
at other times is locked in position and then it forms in effect the end of the air
pump cylinder. The quantity of air delivered by the pump can be varied by
shifting the position of the second piston so as to alter the amount of clearance
between the two,

page_text: Another method of ignition which in some cases I employ consists in providing a
small ignition chamber which at the proper time is placed in connection with the
cylinder. The ignition chamber also communicates with a chimney but a valve
worked by a cam or otherwise closes the passage whilst the ignition chamber is
open to the cylinder. A jet of mixed gas and air compressed by a pump or other-
wise is driven into the ignition chamber. The jet is ignited by a flame in the
chimney just outside the valve. The valve closes at the proper time and then
when the communication with the cylinder is permitted the flame is carried from
the ignition chamber into the cylinder.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is an elevation and Figures 2 and 3 are vertical sections at right angles
to each other of an engine constructed according to my invention.
A is the cylinder. B is the piston which is hollow and filled with asbestos B
and surrounded with a ring B2 provided with packing rings B³. The piston has
on each side trunks B' with flanges at their ends held between the cover plates B'
of the piston. These cover plates are secured together by bolts Bº. CC is the
connecting rod the part C being coupled to the piston by the ball and socket
joint C. The part C carries at one end the bearing C³ of the crank pin D in
which is formed the bearing in which works the lower end of the other part C¹.
At the other end of the part C near the ball and socket joint there is a collar C
which also forms a bearing for the part C. The part or axis C₁ carries at its end
the disc C whose edge is furnished with inclined teeth gearing with spirally shaped
teeth on the disc D' fixed to the crank pin D so that as the crank shaft revolves
the axis C is turned. Near the ball and socket joint the axis C has fixed to it
horns C lying in a slot in the semi-circular yoke piece B7 which is pivotted at B8
to the piston. These parts are also shewn in Figure 4 which is a local section on
the line 1, 1, Figures 2 and 3. In this way the piston is caused to rotate with the
axis C and the crank shaft.
The method of connecting the disc Ce to the axis C is shewn in Figure 5. The
disc has on its back a clip C which receives a worm wheel C on the axis C¹ and
one of the holes through the clip is so bored that the bolt C through it engages
with the teeth of the worm wheel whilst both bolts C & C serve to tighten
the clip and lock the parts together when set.
Figure 6 shews a modified way of causing the axis C₁ to rotate, the discs C
and D' being replaced by a worm wheel C and a worm D' respectively. The
worm wheel C is secured to the axis C in a similar manner to the disc C as
above described.
E Figures 1 and 2 is a casing (surrounding the crank and connecting rod) con-
taining oil or oil and water. E' is a collecting box connected by the pipes E' E³
with the casing E and provided at the top with an air pipe E^.
Figure 6 also shews another way of connecting the rod C to the piston. In this
case the piston has a double bearing on its underside and this receives two opposite
arms or trunnions F F of the cross piece shewn in Figure 6* whilst another bearing
at the end of the axis C¹ receives the arms F' of the cross piece.
Figure 7 is a vertical section and Figure 7* a horizontal section on the line 2, 2,
of an engine in which the piston is caused to rotate by gearing independent of the
connecting rod. The trunk B on the lower side of the piston has slots in it
which receive projections G' upon the inside of the ring G. The top of this ring
is provided on the outside with teeth gearing with the pinion on the shaft H
which carries at its lower end a pinion H2 gearing with the wheel H³ on the crank
shaft. The axis H is extended upwards and drives the governor shewn in Figure 8
which forms a continuation of Figure 7. The axis H has upon it a collar H
and a slider H' connected by the rule jointed links H. At the joints of the links
are weights H' which as the axis H revolves tend to swing outwards compressing
the spring Hand drawing the slider H³ towards the collar H. Inside the

page_text: arm of the T shaped lever H pivotted at H". The other two arms of the
Tshaped lever have teeth upon them gearing with right and left hand worms J
on the sleeve which is free to move up and down on the axis J but rotates
with it the two being connected by the pin J³ fixed to the sleeve and working in
the slot J in the axis. The axis is caused to rotate by the wheel J' fixed to it
which gears with the pinion I fixed on the axis H. The sleeve J has upon it
a number of cams Jone or other of which bears against the roller K¹ upon the
rod K giving motion to the valve mechanism.
Figure 9 shews a modification of this arrangement. In this case the sleeve J
has only one cam J upon it and this is thrown into and out of contact with the
roller by the T shaped lever H0 which in its turn is moved by the cams
surfaces H on the slider H³.
Ingnition is given by means of apparatus shewn by the Figures 10, 11, 12
and 13.
Figure 10 is a vertical section through the cylinder wall and the ignition
apparatus and
Figure 1 is an elevation,
Figure 12 is a section on the line 3. 3. in Figure 10 and
Figure 13 is a section on the line 4. 4. in Figure 10.
In the wall of the cylinder A around the port A' a recess is formed and into
this the hollow recl-shaped plug L is fitted; it is provided with a refractory
lining L'.
The plug is so formed as to leave a sealed cavity L between it and the
cylinder wall and to this cavity an inflammable mixture of gas and air is supplied.
L³ are perforations in the sides of the reel shaped plug through which the gas
and air pass to be burnt in the furnace chamber within it.
Lis wire gauze
9
surrounding the plug to prevent flame from passing out through the perforations
to the inflammable gaseous mixture in the cavity L. The furnace chamber is
formed partly within the plug and partly within a casting L' bolted to the side
of the cylinder a chimney L forms part of this casting. The casting L when
fixed in place forms a tight joint with the outer end of the plug L; it also
receives into it a metal lining L' which is inserted from the open end and then
by a partial turn is locked; projections L upon it engaging with bayonet
grooves in the mouth of the part L'. The lining L is itself provided with a
refractory lining at L. L is a metal, porcelain or other refractory capsule: at
its inner end it enters a seat of suitable form provided for it in the plug Land
the two parts fit together to form a tight joint. At its outer end the ignition tube
or capsule is pressed upon to hold it in its scat by the metal block L" which closes
the end of the lining piece L. L is a hand screw, it works through a threaded
hole in the spring bridge piece L. The ends of the bridge piece L are so made
that they clip upon the outside of the ignition apparatus and the end of the screw
bears upon the block L" and presses it forward. In this manner the ignition tube
or capsule is held to its seat by an elastic pressure which admits of the free
expansion of the tube. Thus it will be seen that the furnace chamber can be
readily opened when required. Ls is a Bunsen burner arranged beneath the
furnace chamber by which I may heat it gradually before starting the engine.
The flame from the burner ascends through apertures L in the casting L and
so to the chimney.
The heating of the furnace chamber and the capsule when at work is performed
by the combustion of gas which enters by a regulating cock at L"; it enters
a tube 18 and is urged forward by an air blast admitted through the small
nozzle piece L". The blast induces more air to enter by the holes L. The
gas and air mixed together pass on into the cavity L thence through the wire

page_text: gauze at Land the passages 13 and into the furnace chamber where they
burn. The igniter is started by holding a light at the top of the chimney.
This improved construction and arrangement of igniting apparatus ensures
certainty of ignition; this results from placing the open end of the capsule near
to the charge to be fired. The blast keeps the capsule in a state of incandescence
and causes a great intensity and rapidity of ignition necessary for high speeds.
The porcelain tube L10 may be open at both ends as shown in Figure 14. In
this case the block L" is made hollow and its end abuts against the end of the
tube L10
This arrangement permits the igniting tube being reversed end
for end.
The air pump M which supplies the jet of air for forcing the furnace is shown
in section at Figure 15. M is a reciprocating plunger in the cylinder M.
M is the inlet valve and M³ is the outlet. This air pump is worked by the
engine from an eccentric acting on an arm M. This arm is upon an axis carried
by a bracket on the frame and upon the same axis there is a disc M³. Upon
another axis in line with the first there is a lever M., The lever M carries upon
it a bolt lever M7 having two bolts which shoot through the lever M into holes in
the disc M³. When thus bolted the eccentric gives motion to the lever Me so long
as the engine runs. The bolt lever M' can however be latched back and the pump
can then be worked by hand.
A block M³ is arranged to slide upon the lever M6 it works as a nut on a
screw M which the lever M also carries. M10 is a connecting rod jointed at one
end to the plunger M³ and at the other to a pin or stud on the block M*. This
arrangement admits of the stroke of the air pump being varied at will. The air
delivered from the air pump by the valve M³ is led by a pipe to the nozzle L.
A spring loaded valve fitted at M allows air to escape when the standard
pressure is reached.
A pipe M Figures 1, 2 and 3 connects the air pump M with an air vessel N
in the base of the engine. This vessel is air tight and connected by a pipe N¹ with
the circulating water cistern or other water vessel (not shown in the drawings)
so as to give a head of water about 5 or 6 feet above the air vessel N which affords
the necessary air pressure to sustain the furnace blast; the pressure can be varied
by raising or lowering the head of water.
The action of the pump forces air into the air vessel N through the pipe M
and displaces therefrom any water contained therein by forcing it back through
pipe N into the cistern or vessel. The pipe connecting the pump with the blast
jet L is fitted with a cock M¹³ which may be opened to supply the furnace blast
simultaneously with the charging of the air vessel N or the cock M may be closed
until the air vessel N is fully charged when the cock M" may be closed to retain
the stored air for starting the furnace. The furnace may also be started by the
direct blast from the pump worked by hand until the engine is put in motion-
then the cock M may be opened to continue the blast at the standard pressure.
The stroke of the air pump is adjusted to supply rather more air than necessary
to maintain the head of water and any excess of air delivered by the pump will
escape by the pipe N¹ through the water to the open air at the water head. Thus
uniformity of air pressure at all speeds of the engine is ensured. If the water head
be not available I close the cock N2 when the vessel N becomes a compressed air
storage chamber.
In case of failure of the pump gear I bring into use to sustain the furnace blast
a pressure supply from the engine cylinder. For this purpose I provide a pipe with
a non-return valve O leading out of the cylinder at a point passed by the end of
the piston at about a half of its outward stroke and a pipe O¹ leading through a stop
valve O' into the lower part of the air reservoir N terminating within the reservoir
in a rose or piece of pipe pierced with numerous small holes.
In some cases I provide the air pump with two pistons P P1 as shown in
Figures 2, 7, 7×, 16 and 17. The piston P receives motion from the eccentric Q

page_text: on the crank shaft. The other piston P¹ is connected to a lever P by which
it can be worked by hand when required on starting the engine being at other
times locked in position and forming in effect the end of the air pump cylinder.
The quantity of air delivered by the pump can be varied by shifting the position
of the piston P¹.
Another method of ignition is shown in vertical section at Figure 18 and in
side elevation at Figure 19.
R is a small ignition chamber opening at R' to the cylinder and at R2 to the
chimney S, the latter opening being closed by a valve T when the chamber is
open to the cylinder. The valve T is operated at the proper times by the
lever T. U is a pipe supplying mixed gas and air, it communicates by a
passage U with the chamber R and by a passage U2 with a burner V, provided
with two diaphragms VV₁ of wire gauze.
The size of the passage U₁ is
regulated by a ball valve U whose lift is limited by the screw U and the size of
the passage U is regulated by the screw U.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. In a gas engine rotating the piston by a disc upon the crank pin having spiral
teeth upon it gearing with teeth upon a wheel fixed to the connecting rod sub-
stantially as described and shown at Figures 2 and 3 of the drawings.
2. In a gas engine rotating the piston by a worm upon the crank pin gearing
with a bevel wheel fixed to the connecting rod substantially as described and shown
at Figure 6 of the drawings.
.
3. In a gas engine a combined clip and tangent worm for fastening and adjusting
the gearing wheels to open and close the ports at proper times substantially as
described and shown at Figures 5 and 6 of the drawings.
4. In a gas engine attaching the piston to the connecting rod substantially as
described and shown at Figures 2 and 3 of the drawings.
5. In a gas engine attaching the piston to the connecting rod substantially as
described and shown at Figure 6 of the drawings.
6. In a gas engine, the combination of a trunk upon the piston, a tube outside
the trunk, connections between the trunk and the tube causing them to rotate together
but allowing the trunk to reciprocate freely in the tube and means for causing the
tube to rotate substantially as described.
7. In a gas engine mechanism for revolving the piston substantially as described
and shown at Figure 7 of the drawings.
8. In a gas engine a piston with trunks attached in such a manner that the piston
and trunks can expand independently of each other substantially as described.
9. In a gas engine the combination of trunks upon the piston, a packing ring
outside the piston connections between the piston and the packing ring causing them
to rotate together but allowing the piston to expand freely in the ring and means
for causing the trunks to rotate substantially as described.
10. In a gas engine pistons substantially as described and shown at Figures 2
and 3 of the drawings.
11. In a gas engine the combination of a closed crank chamber, an air pipe,
a separating vessel, a return pipe and an outlet pipe substantially as described and
shown at Figure 3 of the drawings.
12. In a gas engine controlling the admission of gas by a number of cams placed
side by side one or other of which is put into gear by the governor substantially as
described.
13. In a gas engine the mechanism substantially as described and shown at
Figure 8 of the drawings by which the governor shifts the cams for controlling the
admission of gas.
14. In a gas engine controlling the admission of gas by a combination of cams
operated substantially as described and shown at Figure 9 of the drawings.

page_text: 15. In a gas engine an ignition tube of refractory material pressed by a spring
to a seat so that it is free to expand substantially as described and shewn in
Figure 10.
16. In a gas engine the combination of an igniting tube open at both ends
held in place by a plug and spring pressure substantially as described and shewn
Figure 14.
17. In a gas engine having a pump for supplying air to feed a flame for heating
its igniting tube adjusting the pump delivery by sliding the piece carrying the pump
rod along a lever substantially as described.
18. In a gas engine mechanism for working the air pump and adjusting its
delivery substantially as described and shown at Figure 15 of the drawings.
19. In a gas engine an air pump having two pistons one being driven by the
engine and the position of the other being adjustable to regulate the delivery of air
substantially as described.
20. In a gas engine the air pump and gearing substantially as described and
shown at Figure 2 of the drawings.
.21. In a gas engine an air reservoir connected with an elevated water cistern for
equalising the pressure of the air substantially as described.
22. In a gas engine an igniting chamber in which an intermediate flame is
supplied constantly with gas and air and is opened to the cylinder at the proper
moment by the revolving piston and just previously closed at its outer end by a
valve thus cutting off from it a permanent flame by which the intermediate flaine is
relighted after the explosion substantially as described.
23. In a gas engine an igniting apparatus substantially as described and shown
at Figures 18 and 19 of the drawings. -
Dated this 4th day of Anril 1892
HENRY T. DAWSON..