Year: 1886

page_text: Date of Application, 19th Feb., 1886.
Complete Left, 19th Nov., 1886.
Complete Accepted, 4th Feb., 1887.
I, JAMES SHAW, of Richmond Hill, Leeds, in the County of York, Engineer, do
hereby declare the nature of this invention to be as follows:-
According to my improvements I provide a combustion chamber, equal to one sixth
of the area of the interior of the cylinder in which the piston travels, and I arrange
the parts so that the piston compresses only to the extent of one third of its inward
stroke, all as hereafter described.
When an explosion has taken place and driven the piston five sixths of its stroke
outward, the exhaust is opened for the escape of the products of combustion, and at
that point are provided some openings round the interior of the cylinder for the supply
and air.
of
employ an air pump for the supply of air, the area of which is the same as that of
the explosion or working cylinder.
I employ also another pump to force gas into the cylinder, to mix with the air
supplied by the air pump.
The working piston having arrived at the end of its stroke, the piston in the air
pump travels two thirds of its inward stroke, during this time the explosion or working
cylinder travels back one sixth of its return stroke, the gas pump giving its supply of
gas, also the air pump giving its supply of air.
The working piston continuing its inward stroke, driving in front of it the explosive
mixture, and when it has travelled two thirds back, the exhaust shuts, and the working
piston begins at once to compress the mixture in the combustion chamber, until arriving
at the point for explosion to take place.
I make the area of the gas pump piston the same as that of the piston in the working
cylinder.
The gas pump consists of a cylinder in which is provided a piston having any
required number of openings or passages through it, these being covered by back
pressure valves.
On the piston being moved in one direction the gas passes through the openings to
the top or other side of piston, and on the piston being moved in the opposite direction.

page_text: the back pressure valves close upon the holes, and the gas is forced into the working
cylinder and mixes with the air therein supplied by the air pump.
The gas pump piston is actuated preferably through suitable lever from fly wheel
shaft, and the supply of gas is regulated by governors; that is to say, when the Engine
has attained its required speed the governors through suitable arrangements, stop the
movement of the lever which connects the gas pump with the fly wheel shaft, and so
prevent the action of such gas pump until the governors fall again by reason of a
slight reduction of the speed of the Engine.
For exploding purposes I employ the so called "Watson's Igniter"; but I provide
a valve at the bottom thereof, which closes the tube until the Engine is ready for the
explosion, at which time the valve is withdrawn, a rush of explosive mixture passes up
into the tube, and is immediately exploded.
The aforesaid igniter valve is actuated by some convenient moving part of the
Engine.
For starting the Engine I bring the crank just over the centre, and in the combustion
chamber I provide a valve which opens inwards towards the combustion chamber; at
this point I provide a blue flame, which is sucked in by the movement of the piston,
effected by turning the fly wheel a short distance.
Gas and air having previously been pumped into the cylinder and mixed, an
explosion takes place which puts the Engine in motion.
W. HARDING,
Agent.

page_text: Figs. 5 and 6 are enlarged detail views shewing the mixing chamber hereinafter
described, and Fig. 7 is an enlarged detail view of parts of the igniter also hereinafter
described.
C is the working cylinder; it is made at its inner end 1 of gradually decreasing
diameter and this part is so proportioned and the position of the piston at the termina-
tion of its inward stroke is such that when the piston occupies its innermost position in
the cylinder the space 1 behind it which I call the combustion chamber will have a
cubical capacity equal to one sixth (or thereabout) of the cubical capacity of the
working cylinder U, excluding the combustion chamber and also the portion of
cylinder occupied by, and situate beyond (i.e. in front of) the piston when it has
terminated its outward stroke and therefore occupies its outermost position. At a part
of the cylinder corresponding to the position of the inner end of the piston when it has
completed five sixths (or thereabout) of its outward stroke there are openings 2 into the
cylinder. These openings communicate with a chamber 3 partly surrounding the
cylinder, and provided with a baffle plate 4. The said chamber is in communication
with a pump that supplies gas or vapour and which is hereinafter called the gas
supply pump also with an air supply pump, and constitutes with its baffle plate what
is hereinafter called the mixing chamber. is the gas supply pump. It is so pro-
portioned and operated as to supply a definite quantity of gas or vapour. as required
for each revolution of the engine, as I will proceed to explain.
The piston 5 of this pump may have, (as shewn) the same area as the piston 6 in
the working cylinder C. Through the gas pump piston are passages 7 each provided
with a valve 8. These valves open and allow gas to pass as the piston 5 moves in one
direction and are closed whilst it is making its reverse stroke during, which it forces
gas or vapour through the mixing chamber 3 (in which the gas or vapour is mixed
with air) to the working cylinder C. The piston 5 of the gas supply pump. is
actuated as follows: S is the crank-shaft of the engine: it has a fly wheel W. 9 is a
cam on that shaft. L is a lever pivotted at 11 to the main frame F. 12 is the rod of
the piston 5-it extends through the lower end of the gas supply pump cylinder 13.

page_text: 14 is a spring that tends to keep the piston 5 normally in its lowest position in the
cylinder. Instead of this spring any suitable equivalent arrangement may be adopted,
such as a spring applied outside of and below the cylinder and acting in connection
with the prolongation of the piston rod, to draw down the piston when released by the
lever L. As the shaft S rotates the can 9 depresses the end 10 of the lever L, thereby
raising its end 15, and the piston 5, compressing the gas or vapour then in the
cylinder 13 above the piston and causing flow thereof into the mixing chamber and
thence into the working cylinder C. An anti-friction roller 20 is mounted upon a
stud carried by the lever L, and the cam 9 bears against it.
Referring to the detached side elevation of the cam shown in Fig. 4, in which the
arrow shows the direction of rotation of the shaft S and cam; the piston 5 of the gas
supply pump occupies its lowermost position in the cylinder whilst the part 9" to 9"
is in contact with the roller 20; the piston is raised whilst the part 9b to 9¢ bears
against the roller; is retained in its uppermost position whilst the part 9° to 9ª is
against the roller; and descends whilst the part 9 to 9" is against the roller. For the
purpose of controlling, the engine the governor (which may be of any suitable kind) is
caused to stop and lock the lever L, thereby arresting the action of the gas supply
pump and the supply of gas (or vapour) to the working cylinder C when the engine
has a tendency to "race" or exceed the required speed, as follows: Pivotted at 16 is a
bell crank lever, one arm 17 of which is slotted at 17" and is connected by a rod 19
to the sleeve or equivalent part of the governor; the other arm 18 of the bell crank
lever is made with a bent or shoulder 18". 21 is a stud or projection at the side of the
lever L. When the sleeve or equivalent part of the governor is caused to rise, the
lower end of the arm 18 moves towards the stud or projection 21, and whilst the end
10 of the lever L occupies its lower position the bent or shoulder 18 passes over the
said stud or projection thereby preventing upward movement of the said end 10 of the
lever, and consequent descent of its other end and of the pump piston 5 until by
the action of the governor the bent or shoulder 18" is moved clear of the stud or
projection 21.
A is the air supply pump; it is worked from a disc or other crank on the shaft S.:
the cubical capacity of the pump cylinder (excluding the portion occupied by its
piston) may advantageously equal that of the working cylinder C as hereinabove
defined. The arrangement is such that when the engine piston has accomplished five
sixths or thereabout of its outward stroke the air pump will have compressed and forced
a supply of air into the mixing chamber in readiness to enter the working cylinder as
a scavenging charge. The air pump will continue to supply air until the engine piston
las completed its outward stroke and about one sixth of its return or inward stroke ;
and during this part of the return or inward stroke of the engine piston the gas
supplying pump will also be supplying gas (or vapour) and such air and gas (or
vapour) will be mixed in the mixing chamber and fed to the working cylinder as a
combustible mixture.
As the engine piston continues its inward stroke it will drive before it the explosive
mixture; any, residue remaining in the working cylinder and combustion chamber
from the previous explosion, also any air, will be expelled; and when the piston has
accomplished two thirds or thereabout of its inward stroke, the exhaust will be closed ;
during the remainder of its stroke the piston will be compressing the combustible
mixture until on completion of the stroke the said mixture will have been compressed
in the combustion chamber 1 to a volume equivalent (as I prefer) to one sixth or
thereabout of the entire cubical capacity of the working cylinder as hereinabove
defined. 22 is the exhaust passage, 23 the exhaust valve, 24 its spindle, and 25 a spring
that acts to keep the valve closed normally. Through a guide bracket 26 works the
end 27 of a rod 27 operated by an eccentric 28 on the shaft S. By pressing against
the spindle 24 this rod opens the exhaust valve 23 in opposition to the spring 25.as
and when required. The eccentric is (as I prefer) so set that the exhaust valve shall
be opened when the engine piston has accomplished five sixths or thereabout of its
outward stroke and be kept open until the said piston has accomplished two thirds or
thereabout of its inward stroke. O is an additional exhaust passage.

page_text: In the arrangement shown the piston of the air supply pump is made to serve as a
valve for opening and closing this additional exhaust passage 0%. It will be seen
there is a pipe from 02 to the outer end of the air pump cylinder at one side, a spout
pipe at the other side, and a transverse passage through the piston; but a separate
valve may be used to control this supplementary exhaust in lieu of employing the air
pump piston for that purpose.
From the foregoing description it will be understood that in an engine such as
illustrated in the annexed drawings in which the piston is propelled outward by
explosion and expansion of a combustible mixture of gas or vapour and air behind it,
the exhaust is opened and air alone is forced as a scavenger into the cylinder through
holes uncovered by the piston when it has accomplished five sixths or thereabout of
its outward stroke; combustible mixture is forced into the cylinder through the said
holes after the piston has completed its said stroke and whilst it is making the earlier
part of its inward stroke preparatory to closing the said 'holes; any residue from the
previous explosion still remaining in the cylinder or combustion chamber, as also air
forced alone into the same, will be expelled during the inward stroke; the exhaust
will be closed when the piston has accomplished two thirds or thereabout of its
inward stroke; and during the remainder of such stroke the piston will be compress-
ing the combustible mixture in the combustion chamber at the inner end of the
cylinder There is an explosion at each revolution.
:
For the purpose of exploding the compressed charge of combustible mixture in the
combustion chamber 1 the arrangement of igniter illustrated is as follows:-32 is a
tubular chamber with a lining 33 of refractory material such as asbestos; 34 is
intended to represent the flame of a Bunsen burner; 35 is a small metal tube, closed
at its outer end, and kept red hot by the flame 34 36 is a pipe, the inner end of
which forms an annular valve; this pipe passes through a stuffing box to the outside
of the cylinder C, and at its inner end is guided by a guide 37. The outer end of
the pipe 36 is closed, but there is a very small hole (say about equal in area to the
cross section of an ordinary pin) at 38. 39 is a rock shaft on which are fixed two
arms 40 and 41. The arm 40 engages with the outer end of the pipe 36; the arm 41
has connected to it a spring 42, by the action of which the annular valve at the end of
the pipe 36 is kept normally against its seat. 43 is an eccentric on the shaft S-the
end of its rod 44 once during each revolution of the engine, that is to say immediately
after compression of a combustible charge in the chamber 1, opens the annular valve
by pushing the arm 41 in opposition to the spring 42. On the opening of the valve
there is a rush of gas along the pipe 36 and through the small hole 38. This helps to
insure immediate ignition and explosion of the compressed combustible charge in the
combustion chamber 1 by means of the highly heated tube 35 as well understood.
In the drawings is shown an arrangement that may or may not be used for starting
the engine. 45 is a tube of any suitable section extending into the combustion
chamber 1, and provided with a flap valve 46 opening into that chamber. To start
the engine with this arrangement the crank is moved just over the dead centre; a
blue flame is applied in the tube 45. A combustible mixture having been previously -
pumped into the cylinder, and the partial rotation of the fly wheel being continued so
as to expand such mixture until it is slightly below the atmospheric pressure, the flap
valve will open and the flame will ignite the combustible mixture.
The valve described will also serve to prevent formation of a partial vacuum in the
working cylinder in the event of non-ignition of a charge in the combustion
chamber.
Having now particularly described and ascertained the nature of the said invention,
and in what manner it is to be performed, I declare that what I claim is :-
1. In a gas engine in which the piston is propelled outward by explosion and
expansion of a combustible mixture of gas or vapour and air behind it admitting
the combustible mixture to the cylinder, near the outer end thereof whilst the piston
is making the earlier part of its inward stroke, substantially as described.
2. In a gas engine in which the piston is propelled outward by explosion and

page_text: expansion of a combustible mixture of gas or vapour and air behind it; causing
(a) the exhaust to be opened and air alone to be forced into the cylinder through holes
uncovered by the piston before it has completed its outward stroke (b) combustible
mixture to be forced into the cylinder through the said holes, after the piston has
completed its outward stroke and whilst it is making the earlier part of its inward
stroke (c) expulsion of remaining residue and of air during such inward stroke, and
(d) closing of the exhaust and compression by the piston of the combustible mixture,
preparatory to ignition and explosion for the next outward stroke all substantially as
described.
3. In an engine such as referred to in the preceding claim, reducing the combustible
mixture by compression before ignition in the combustion chamber or space at the
inner end of the cylinder to a volume equivalent to one sixth or thereabout of the
cubical capacity of the working cylinder as hereinabove defined.
4. Arranging and actuating substantially in the manner described, the pump
whereby gas is supplied to the engine in definite quantity.
5. The mixing chamber in connection with the gas supply pump and air supply
pump and having openings therefrom into the working cylinder, the construction and
arrangement being such that gas or vapour and air are forced into the said chamber
and mixed preparatory to entering the working cylinder through the said openings,
substantially in the manner described.
6. For the purpose of controlling the engine causing the gas supply pump to be
stopped by the action of the governor as required to arrest the supply of gas or
vapour, substantially in the manner described.
7. Providing the igniter with a valve, substantially as described.
8. The improved gas engine substantially as described and shown, whether with or
without the starting arrangement, and whether or not the air pump piston be used
also as a valve for the additional exhaust passage.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.