IMPROVEMENTS IN MOTIVE-POWER ENGINES WORKED BY THE EXPLOSION OF GAS
Year: 1877

page_text: LETTERS PATENT to Edgar Coniston Mills, of Manchester, in the County of
Lancaster, Engineer, and Henry Haley, of the same Place, Engineer, for the
Invention of "IMPROVEMENTS IN MOTIVE-POWER ENGINES WORKED BY THE
EXPLOSION OF GAS."
Sealed the 29th January 1878, and dated the 8th August 1877.
PROVISIONAL SPECIFICATION left by the said Edgar Coniston Mills and
Henry Haley at the Office of the Commissioners of Patents on the 8th August
1877.
EDGAR CONISTON MILLS, of Manchester, in the County of Lancaster, Engineer,
and HENRY HALEY, of the same Place, Engineer. "IMPROVEMENTS IN MOTIVE-
POWER ENGINES WORKED BY THE EXPLOSION OF GAS."
Our Invention relates especially to improvements upon that arrangement of gas
engine for which Letters Patent were granted to us bearing date 23rd January
1875, No. 265, but applicable also to engines of other constructions, as will be
pointed out.
One object of our present Invention is to obtain a greater amount of power with
a given size of cylinder, and this we accomplish by the employment of arrangements
which enable us to work each single stroke with explosive force on one side of the
piston and a partial vacuum on the other.
Another part of our Invention relates to a method of governing gas engines, such
as those now described, our object in this case being to make the number of
explosions in a given time proportionate to the work required of the engine.
In carrying out our Invention we use a cylinder, piston, and crank, but no fly
The cylinder
wheel, as ordinarily applied, for a reason which will hereafter appear.
is provided with valves at each end, which, when the piston has moved a certain
distance, and when an explosive charge has been drawn in, receive a sudden motion
for cutting off the supply, and at the same time injecting the igniting flame
alternately at each end of the cylinder. These motions we propose to effect by a

page_text: cam acting upon suitable rods and spring connections. The explosion having taken
place the piston is driven forward by the expanded gases to the end of the cylinder.
Immediately the crank has turned the centre the piston begins to move back by
atmospheric pressure only, there being a partial vacuum on the other side thereof due
to the attenuated gases which have expended their elastic force, and and this motion
continues until the explosion takes place, as above described, but now at the other
end of the cylinder; and then there are two forces employed, one arising from the
expansion of the heated gases, and the other due to the partial vacuum on the other
side of the piston, and in this manner the engine continues to work.
There is an exhaust valve at each end of the cylinder, which, by a slight motion
imparted from the crank shaft, allows the residues of the exploded gases to escape,
but which prevents the atmosphere from entering.
According to the second part of our Invention we cause the motion of the piston
and connected parts to be controlled at certain times by an effort required to drive
water or other fluid through an orifice which may be regulated in area.
In practice we propose to place a cain or other such apparatus on the crank shaft,
which, when the piston is starting from the cylinder end, pushes a roller which can
only yield according to the flow of a liquid from a small cylinder provided with a
piston, and therefore by adjusting the aperture of egress the speed of the main
piston during a part of its stroke can be governed. When the explosion takes
place, the aforesaid roller having reached the end of the path on the cam, the piston
is free to move rapidly by the force of the explosion on one side thereof, and
pressure of a partial vacuum on the other, and the above-described operation takes
place at each end of the cylinder.
The regulation of the orifice may be effected by an ordinary governor or other
such apparatus, in the case of the arrangement patented by us as aforesaid, by the
pressure existing in the air reservoir, or by manual arrangements.
The fluid which is necessarily discharged from the small cylinder may beused
continuously, or employed for any other useful purpose.
The above-mentioned small cylinder is allowed a slight longitudinal motion due
to elastic buffers or similar apparatus.
In some gas engines we adopt a system of governing by which the number of
explosions in a given time remaining constant or nearly so, the amount of mixed
air and gas exploded for each stroke may be varied according to the work required
of the engine. In this case the amount of air and gas measured, mixed, and
delivered for the use of the engine must also be variable. For this purpose we
propose to employ an ordinary governor driven from the main shaft, and which
actuates an arrangement of star wheel and screw, by which the moment of release
from the control of the above-mentioned hydraulic cylinder and the simultaneous
moment of explosion are made earlier or later. The star wheel and screw operate
so as to alter the relative positions of the crank and the governing and valve cams.
For varying the amount of charge prepared for feed the governor causes a clutch
piece with taper teeth to slide on a shaft which drives it by means of a feather. In
sliding on the shaft it approaches or recedes from another similarly constructed
clutch piece, and by giving more or less back lash in the teeth transmits more or
less of its alternate rotatory motion to the second clutch piece which actuates the
measuring apparatus.
We have above stated that our Invention is chiefly applicable as improvements
upon our former Patent aforesaid, but it may also be adopted to certain other
gas engines, as that, for instance, for which Letters Patent were granted to
C. T. E. Lascelles, dated 10th May 1876, No. 1961; and another part of our
Invention relates to an improvement upon the Patent of the said C. T. E. Lascelles,
and consists in a method of obtaining what may be called an elastic connection.
To this purpose a fly wheel is mounted upon the crank shaft or upon a secondary
shaft, and attached to the said fly wheel or to any other wheel which drives it is a
chamber with a fixed abutment or division, and in the said chamber is a vane
carried by the crank shaft, which, as it revolves, carries round this vane and

page_text: compresses the air enclosed between it and the first-mentioned abutment, by which
agency therefore the latter is driven and the required elasticity obtained.
In connection with the above-mentioned air apparatus or modification thereof, or
with a metallic spring, as described by C. T. E. Lascelles aforesaid, we propose to
employ an arrangement the object of which is to receive the force of the explosion
at its most advantageous point, and to redeliver the stored up power at the end of
each engine stroke. For this purpose we employ a spring, one end of which is
attached to a wheel, and the other end to the frame by means of an oscillating case.
The said wheel gears into another of twice its diameter fixed upon the crank shaft
of the engine.
For restarting gas engines in which a friction clutch is employed to prevent
backing we provide the exterior of the clutch casing with a worm wheel, and in
gear therewith we adapt a worm, which, on being rotated by any suitable means,
gives a starting motion to the engine.
In gas engines used for compressing air, as in our former Patent aforesaid, we.
propose to place the air pump alongside the gas cylinder, and driven from the crank
shaft instead of by the same piston rod, in which case we place the crank which
drives the air pump at such an angle with that of the gas cylinder as to turn its
centre when the forces in the gas cylinder are about disappearing. As in this case
it is desirable to have a shorter stroke in the air pump than in the gas cylinder we
allow the piston rod in the former a certain amount of travel before the piston
begins to move, and this we propose to accomplish by collars on the piston rod or
by equivalent means.
In compressing air by gas engines we place a valve upon the exit pipe of the air
pump to effect a constant resistance, but allowing the compressed air to flow readily
into the receiver at any pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the.
said Edgar Coniston Mills and Henry Haley in the Great Seal Patent Office
on the 8th February 1878.
EDGAR CONISTON MILLS, of Manchester, in the County of Lancaster, Engineer,
and HENRY HALEY, of the same Place, Engineer. " IMPROVEMENTS IN MOTIVE-
POWER ENGINES WORKED BY THE EXPLOSION OF GAS."
Our Invention relates especially to improvements upon that arrangement of gas
engine for which Letters Patent were granted to us bearing date the Twenty-third
January, One thousand eight hundred and seventy-five, No. 265, but applicable also
to gas engines of other constructions as will be pointed out.
:
The first part of our Invention has for its object to obtain a greater amount of
power with a given size of cylinder, and this we accomplish by the employment of
arrangements which enable us to work each single stroke with the explosive force
and atmospheric pressure on one side of the piston, and a partial vacuum on the
other.
In describing this part of our Invention we refer to Figs. I., II., III, and IV.,,
Sheet I., which represents in elevation, plan, and end views, a gas engine in section,
and constructed according to our Invention; but in order to explain the principle
of action of the first part of our Invention, it will only be necessary in the first.
place to refer to the cylinder piston and valves, leaving other parts which are
shewn, and which embrace other points of novelty for subsequent explanation. At 1.
is the cylinder, provided at each end with valves 2, 2ª, of any ordinary construction
for supplying the cylinder with the mixed gasses, and subsequently admitting the
exploding light shewn at 3, and also with exhaust valves 4, 4a In Fig. 1 the
section is so drawn as to shew an induction valve 2 at one end, and an exhaust
valve 4 at the other. At 5 is the piston, its rod 6 being connected to the crank
shaft 7, and reserving at present a description of the method of working the
valves.
The operation of the piston is as follows, but in describing it, it will be necessary
to assume that certain operations have taken place, by means of which there is a
partial vacuum in the part A of the cylinder, and how that has happened will here-
after be seen. The position of the parts in Figs. I. and II. are not the same, but
referring to the former, the space B has been charged with the mixed gasses which
are just about to be exploded, the exhaust valve 4 being closed. When this
explosion takes place the piston will be driven forward in the direction of its arrow
against the assumed partial vacuum in the space A, and shortly before it arrives at
the end of its stroke the exhaust valve 4 (Fig II.) is opened to allow of the expul-
sion of remaining gasses in the space A. - The piston having arrived at the end of
its stroke, the exhaust valve 4 closes again, and the induction valve 2 opens for
supplying the mixed gases to the space A. x. The piston is now ready to return, and
its surface is acted on by atmospheric pressure and moved backward against a partial
vacuum now existing in the space B, such vacuum being due to the cooling of the
gasses which have been exploded therein as above referred to, and this travelling of
the piston by atmospheric pressure continues until it arrives in the position shewn
by dots, and which corresponds to that for the other end of the cylinder shewn by
the full lines. When the gasses are exploded the piston is driven in the direction of
The
the dotted arrow against the vaccuum on its other side above referred to.
piston having arrived again at 5, near the right-hand end of the cylinder, the
exhaust valve 4a is opened for the expulsion of remaining gasses, and after the
completion of the stroke the piston then moves back by atmospheric pressure due
to the cooling of the gasses in the space A (the exhaust valve 4 being still closed),
and an explosion having been effected in the space B, the operations above described
take place, and so on for each single stroke.
We now proceed to describe a method we employ for working the above-men-
tioned induction and eduction valves, referring to Fig. 11. (as well as Fig. IV.),

page_text: which is a detached view, as the parts therein shewn, or some of them, are situate
on the same plan as others represented in Fig. 1. At 7, as before stated, is the
crank shaft, on which there is a cam working in contact with a bowl 9, carried by
a lever 10, turning upon a centre 11, and the lower part of which is jointed to a
rod 12. This rod is connected at its other end to a bell-crank lever 13, mounted so
as to be capable of turning upon a centre 14, the other arm of the said bell crank
being provided with a pin situate in the slot of a rod 15, the lower end of which is
forced upward by a spring 16, and the upper end being connected to the induction
and igniting valve 2. As the cam 8 (travelling in the direction of the arrow)
revolves, its surface turns the lever 10 on its centre 11, thus causing the rod 12 to
slide in the direction of its arrow, whereby the valve 2 will be moved downward
through the agency of the bell-crank lever 13, and thus the left-hand end of the
cylinder will be supplied with the mixed gasses, while at the same time the spring
16 will have been compressed so as to be charged with power. The point 17 of the
cam 8 now arrives against the bowl 9, and when past it, the charged spring 16
suddenly forces upward the valve, and effects the ignition of the gasses in the well-
known manner, the master light being shewn at 3.
The above description refers to the left-hand end of the cylinder; the right-hand
end valve is worked in a similar manner by a lever 10 and 12ª, and spring appa-
ratus answering to that shewn at 16, but not shewn in the Drawing. The bowl 9a
is shewn as just about to leave the point 17 of the cam, and corresponds therefore
with the position of the piston shewn by full lines in Fig. I., wherein an explosion
is about to take place. The exhaust valves are worked so as to come into opera-
tion at the times above explained by a groove cam 20, in which there are bowls
21, 22, actuating rods 23, 24.
.
The second part of our Invention consists in governing the engine by apparatus
which regulates the number of explosions in a given time, proportionately to the
work required, and is shewn at Fig. I. above referred to, the apparatus we employ
being also applicable to other purposes connected with the working of the engine, as
will be pointed out. At 25 are brackets, within which is placed a cylinder 26,
filled with water or other fluid, and provided with passages 27, 28, between which
is a plug tap 29, the said passages leading to opposite sides of a piston 30, mounted
on a rod 31. To this rod are jointed two levers 32, 32, turning upon centres 33, 33ª,
and carrying bowls 34, 34, in contact with a cam 35, fixed upon the crank shaft 7.
As the cam 35 revolves in the direction of the arrow, no motion will be imparted to
the lever 32 until the point 40 arrives in contact with the bowl 34, but then by the
lever 32 being turned upon its centre the piston 30 will be forced along the cylinder,
and the fluid therein will be driven through the passage 28, tap 29, and passage 27
to the other side of the piston 30, and the effort to do this will retard the motion of
the crank shaft in proportion to the throttleing of the passages 27, 28, by the tap 29.
This retardation begins to take place when the piston 5 of the engine begins to
move from the end of the cylinder, and lasts until the said piston has moved suffi-
ciently to allow the mixed gasses to enter the cylinder ready to be exploded, by
which time the point 40% of the cam 35 passes the bowl 34, which then being no
longer pressed outward, the working piston 5 will be free to be driven forward by
the explosion, allowing sudden and free expansion of the gasses. The above descrip-
tion has referred to the left-hand side of the cylinder in Fig. I., but the same effect
takes place at the right-hand side thereof, through the medium of the lever 32*, and
the Drawing shews the parts just as the said lever 32ª is about to leave the point
40 of the cam, an explosion being just about to take place, as before mentioned,
in the space B. The Drawing shews a hand wheel 45 and worm gearing 46, by
means of which the tap 29 may be turned so as to cause a more or less contraction
of its orifice, and thus throttle the passages 27, 28, to any desired amount, and thé
retardation of the speed of the engine may therefore be varied while the piston
passes through the spacè B and the corresponding space at the other end of the
cylinder. By these means an extra amount of time may be gained for the mixing

page_text: and firing of the gasses, and also for allowing the exploded gasses on the opposite
side of the cylinder to lose their beat.
An important feature of this part of our Invention, however, is that we are enabled
to govern the engine thereby, for it is obvious that by varying the time of the
travelling of the piston through the spaces which are being charged with explosive
mixture, the number of explosions in a given time may be varied, and the engine
therefore governed according to the work required, and we will now proceed to
describe certain methods by means of which such governing may be automatically
effected. Fig. V., Sheet II., shews one method. At 48 is an ordinary governor
provided with two bevil wheels 49, and an intermediate disc or cottar 50, as in a
well-known arrangement, and at 51 is the pinion of such arrangement, on the axis
of which is a pulley 52, driving another 53, which takes the place of the hand wheel
45 of Fig. I., Sheet I: As the pinion 51 is driven in the one direction or the other
by the usual action of the governor, the pulley 53 is so turned, and by means of its
shaft and worm, and worm wheel, partially opens or closes the tap 29 Fig. I.
Fig. VI., shews a method by which the compressed air in the receiver (Figs. II. and
III.), or of our former Patent aforesaid, is used to produce the automatic governing.
At 54 is a cylinder capable of being supplied with air, under pressure from the afore-
said receiver by means of the pipe P, and of acting against a piston 55, which is
provided with a rod 56, capable of being pressed downward by a spring 57 abutting
against a fixed stop, 58. The upper end of this rod has a fork which encloses the
shaft 59 of a governor such as aforesaid. When the air in the receiver rises above
a given pressure it forces the piston 55 upward against the spring 57, and the rod
56 rising therewith shifts the cottar 50 so as to turn the pinion 51 in the direction
for decreasing the orifice of the tap 29, but when the pressure of the air is below the
required amount the spring 57 forces 'the rod 56 downwards, and pinion 51 is turned
in the other direction so as to enlarge the orifice of the said tap.
Having thus described the operations of this part of our Invention we again refer
to Fig. 1, Sheet I., to explain a particular adaptation thereto. The cylinder 26 is
formed with a flange, between which and the sides of the brackets 25 are rings of
india-rubber 60, the object of applying which is to form an elastic abutment for any
shock which may take place by the changes of directions in which the fluid is pro-
pelled by the piston 30. The Drawing shews the india-rubber rings as divided by
discs, but these are not indispensable. The elasticity of the rings may be modified
by set screws 61.
In the foregoing description we have assumed that the same fluid is continually.
driven from one side of the piston to another, and in that case any ordinary pro-
vision may be made for supplying any deficiency from leakage, but instead of this
arrangement the fluid might be discharged at each stroke of the piston, the
cylinder 26 being provided with suitable valves, and in this case acting as a
pump for any ordinary purpose.
The third part of our Invention relates to a system of governing by which the
number of explosions in a given time remaining constant, or nearly so, the amount
of mixed air and gas exploded for each stroke is varied. This arrangement is shewn
at Figs. VII. and VIII. At 7, as before, is the crank shaft, upon which is mounted
(but in this case loosely) the cam 35, which belongs to the retarding apparatus, as
before pointed out, and attached to it the cam 8 which, as before described, is used
for working the inlet valves. At 65 is the crank, to which one end of a link 66 is
jointed, and the other end to a nut 67; and at 68 is another link, one end of which
is jointed to the cam 35, and the other to the said nut 67. At 70 is a screw capable
of working the nut 67 inward or outward bodily from the centre of motion, and
carrying at its other end a bevil pinion 71 in gear with another 72, fast with a spur
wheel 73 in gear with another 74, the axis of which is provided with a star wheel 75,
the whole of this gearing revolving bodily with the cam 35:
In Fig. VIII., an ordinary governor is shewn, to the moveable part 76 of which
is connected an arm 77 turning on a centre 78 and provided with two projecting
fingers 79.
As the governor causes the arm 77 to turn upon its centre in the one

page_text: direction or the other, one of the two fingers 79 is advanced and caused to intrude
upon the orbit of the spokes of the star wheel 75, and therefore that wheel, as it
rotates bodily round, is obstructed and will be caused to revolve on its own centre
in the one direction or the other and through the gearing 74, 73, 72.
71 will turn
the screw 70 so as to move the nut 67 inward or outward, and by thus increasing or
decreasing the obliquity of the links 66, 68, turn the cam 35 backward or forward
upon the crank shaft and thus alter the lead so as to admit the mixed gasses and
explode them early or later.
The fourth part of our Invention relates to an improvement upon the Patent of
C. T. E. Lascelles, dated Tenth May, One thousand eight hundred and seventy-six,
No. 1961, and consists in a certain method of obtaining an elastic connexion with
the fly wheel. This is shewn at Figs. IX. and X., Sheet III. At 7 is the crank
shaft, upon which is mounted loosely a cylindrical box 80 which incloses a vane 81,
packed air-tight against the internal periphery of the said box, its boss being keyed
fast to the crank shaft. Attached to the box 80 is a partition 82, its inner end
being made air-tight with the boss of the vane 81, but capable of moving
freely thereon. To the box 80 is attached a disc 83, which serves as a cover,
and is provided with an internal toothed wheel 84, in gear with pinions 85,
supported by the bracket 86, which pinions are in gear with another, 87, fast
upon a collar 88, which carries the fly wheel 89 and driving pulley 90, the
said collar running loosely on the crank shaft 7. By this arrangement the
vane 81 (fast with the crank shaft) springing forward in the direction of the
arrow gives motion to the partition 82, when an explosion takes place through
the medium of the elastic force of air within the space A of the box 80. The
internal wheel 84 and the disc 83 transmit motion to the collar 88 and fly
wheel 89 by means of the carrier pinions 85 and pinion 87, by which means
the power of the engine is exerted through the medium of an elastic connexion.
At 91 are apertures for preventing a rarification of the air behind the vane 81,
and at 92 is a snift valve for admitting air to the space A should it become
attenuated. The arrangement shews that the fly wheel runs at a greater speed than
the 'crank.
Fig. XI., shews a modification of the above. The cylindrical box and its vane
and partition are as before, but in this instance the fly wheel is attached to the
periphery of the said box, and the two parts therefore revolve at the same speed.
Fig. XII. shews another modification. In this instance the box 80 is provided
with a spur wheel 100 which drives another 101 on the axis of the fly wheel 89,
which, as in the first case, may thus run at a greater speed.
The fifth part of our Invention relates especially to gas engines used for com-
pressing air, as in the case of our foriner. Patent aforesaid, and is shewn at Figs. I.
and II., Sheet I., before referred to. At 102 is the air pump, placed alongside the
gas cylinder instead of in a line therewith, and worked by and driven by a separate
crank 103. This crank (see Fig. 1) is placed at such an angle as regards that, 104, of
the gas cylinder, as to turn its centre when the forces in the gas cylinder are about
disappearing, as shewn by the positions of the two cranks and pistons in Fig. II.
The object in this case being to make the period of greatest pressure in the gas
cylinder to coincide, or nearly so, with that in the air pump, and in order to relieve
the gas piston of resistance during a small final portion of each stroke, and also
during the retarded or charging period at the commencement of each stroke, we use
the following arrangement, which allows a shorter stroke in the air pump than in
the gas cylinder. At 105 is the piston of the air pump and at 106 the rod thereof;
but in this case it is capable of sliding in the piston between two collars 107, 108.
According to the position shewn the piston rod is about to move in the direction of
its arrow, and in so doing will slide through the piston until the collar 107 arrives.
in contact therewith, after which it is forced forward to the end of its stroke, the
chamber 109 admitting the rod. On the return motion the same effect takes place,
excepting that the piston 105 is now carried forward by the collar 108.
Sheet IV., Figs. I., II., III., and IV. shew an engine combining the valve arrange-

page_text: ments, herein-before described, for double-action explosive and atmospheric effects,
with the elastic connexion, also herein-before described, for obtaining a powerful
and even rotatory motion, the reference numbers in this case corresponding with the
previous description of each part respectively. To this engine the governing
arrangement for altering the lead or angle of the cams 8 and 35, Figs. VII. and
VIII., Sheet II., can with advantage be applied, although not shewn in the
Drawing.
Having thus described and ascertained the nature of our said Invention and the
manner in which the same is to be performed, we desire it to be understood that we
claim as secured to us under the above in part recited Letters Patent, for the
purposes above set forth and substantially as follows:-
In the first part, in gas engines with a single piston, the use of arrangements
whereby there is upon each single stroke a partial vacuum on one side of the said
piston simultaneously with explosive force and atmospheric pressure on the other
side thereof.
In the second part, governing gas engines of the class described in our former
Patent aforesaid, and as shewn on Sheet I. of our present Drawings (when engines
have no fly wheel), by apparatus which regulates the number of explosions in a
given time proportionately to the work required of the engine; also in gas engines
such as herein described, causing the motion of the piston to be retarded at stated
periods by forcing a fluid through an orifice capable of being regulated in area; also
the use of india-rubber or other elastic buffers in connection with the said retarding
apparatus.
In the third part, the use of apparatus for altering the lead or angle of the cam
or other such part which works the valves.
In the fourth part, and when an elastic connexion is introduced between the
motions of the piston and the fly wheel, the method of obtaining such connexion for
double-acting engines.
In the fifth part, and in reference to air-compressing engines, placing the air pump
alongside the gas cylinder and disposing the cranks of the two in the relative
positions above described; also, allowing a certain amount of play between the
piston and its rod.
In the sixth part, the combined engine, as shewn on Sheet IV. of the accompanying
Drawings.
In witness whereof, we, the said Edgar Coniston Mills and Henry Haley,
have hereunto set our hands and scals, this Seventh day of February, in
the year of our Lord One thousand eight hundred and seventy-eight.