Improvements in Steam Engines.
Year: 1897

page_text: Date of Application, 8th Feb., 1897
Complete Specification Left, 8th Nov., 1897-Accepted, 5th Feb., 1898
PROVISIONAL SPECIFICATION.
Improvements in Steam Engines.
I, ALAN ERNEST LEOFRIC CHORLTON, of Oak House, Audenshaw, in the County
of Lancaster, Engineer, and ERNEST JAMES TRAVERS, of the Britannia Works.
Springfield Road, Belfast, Ireland, Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to single-acting, high speed, engines, such as are used
for the direct driving of dynamos and other quick running machinery and
apparatus.
According to my invention, I admit and employ the steam on the side of the
piston nearer to the big-end, and am by this and other means hereinafter des-
cribed, enabled to have the rod or equivalent means for connecting the piston
with the big-end, always under tension instead of being alternately under tension
and compression as is usual, I can thus employ a much lighter connecting rod
and can advantageously construct it of laminated steel at a minimum cost.
I may employ valves of the ordinary construction, but by preference I use a
valve or valves of special design, and in the case of a compound engine, arrange
a single valve for both cylinders. This valve is of the oscillatory cylindrical
type, and may be arranged at the end of the cylinders nearer to the crank. The
exhaust from the high pressure cylinder enters the interior of the valve, passes
along it and enters the low pressure cylinder. To ensure the adjustment of the
valve face on its seating for wear, I may arrange between the valve spindle and
the valve wall one or more springs, which will not only effect the purpose
intended but will also eliminate knocking.
The valve may be actuated through a pulley fixed on the valve spindle,
by a steel or other band or strap passing around it. The two ends of this band
are fixed to an adjusting screw to take up stretch. Between this point and the
valve pulley, the two parts of the band pass in contact with two excentrics or
with arms or levers connected with two excentrics. These excentrics are mounted
at 180° on the orank shaft and by their action, whilst one end of the band is
pulled the other is allowed to follow. The ends being pulled alternately, oscil-
latory motion of the valve ensues. The band is always in tension, and may be
adjusted whilst the engine is running. I may arrange in connection with the
valve spindle, an air buffer on the dash-pot principle, to gradually arrest the
motion at the end of each oscillation. This may be arranged in connection with
the pulley which may be in the form of a closed cylinder connected with the
spindle by two radial blades 180° apart. At right angles (with these there are two
other radial blades attached to a fixed part. Thus as the pulley blades approach
the fixed blades, first on one side and then on the other, the air between them
becomes gradually more and more compressed and the reverse. At the commence-
ment of the stroke, of course the compressed air helps the reversal.
The engine connecting rod is connected to a trunk, and the trunk to the piston.
Around the trunk there is an annular chamber which is in communication with
the interior of the piston, both of which contain live steam when the engine is

page_text: running. As the piston approaches the crank, the length of the annular chamber
becomes reduced and consequently the volume of contained steam becomes com-
pressed, acting as a buffer and to keep the connecting rod in tension. That part
of the piston which works in the annular chamber, which is of smaller diameter
than the cylinder, may have between it and the piston a part of smaller diameter,
so that the shoulder between the two diameters may internally open and close the
port at fixed parts of the stroke.
n
.
We, ALAN ERNEST LEOFRIC CHORLTON, of Oak House, Audenshaw, in the County
of Lancaster, Engineer, and ERNEST JAMES TRAVERS, of the Britannia Works.
Springfield, Road, Belfast, Ireland, Engineer, 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 relates to single-acting, high speed engines, such as are used
for the direct driving of dynamos and other quick running machinery and
apparatus.
We will describe our present improvements with reference to the accompanying
drawings in which:-
Figure 1 represents a partial vertical longitudinal section and Figure 2, a
sectional end elevation of an inverted vertical engine constructed to embody our
improvements.
Figure 3 shews a section taken along the line - Figure 1.
Figure 4 is a sectional side view and Figure 6 a sectional front view of the
connecting rod, part of which is represented as being broken away.
:
Figure 6 shews a sectional side view of a modified form of the connecting
rod.
Figure 7 illustrates a longitudinal section and Figures 8 and 9 transverse
sections of the valve, Figure 8 being a section taken along the linear, and
Figure 9 along the line y-y, Figure 7.
Figure 10 represents a sectional side view of the valve motion and Figure 11
an enlarged section taken along the line a-a Figure 10. Figure 12 shews a
further section taken along the line bb, Figure 10.
Figure 13 shews a sectional plan, and Figure 14 a sectional end elevation of
the air buffer.
According to our invention we admit and employ the steam on the side A of
the piston B, which is nearer to the big end or the crank shaft, as shewn by
Figure 1, in which the piston is shewn at the end of its active stroke. By this
and other means hereinafter described, we are enabled to have the rod or equi-
valent means for connecting the piston and crank, always under tension instead
of alternately under tension and compression as is usual. We can thus employ
a much lighter connecting rod and can advantageously construct it of laminated
steel at a minimum cost.
We may employ valves of the ordinary construction for steam admission and
exhaust, but (by preference) we use a valve or valves of special design and, in
the case of a compound engine, we prefer to arrange a single valve for both
cylinders. This valve, separately shown by Figures 7, 8 and 9, is of the oscil-
latory cylindrical type, and may be arranged at V, that is to say at the end of the

page_text: cylinder or cylinders nearer to the crank. This valve V₁ is mounted upon the
spindle V and has, between its flattened spindle and the shell, a spring V³ which
is intended to enable the valve to adjust itself on its seating and to prevent
knocking. In the case of a compound engine, the exhaust from the high pressure
cylinder enters the interior of the valve and passes along it to the low pressure
cylinder.
The valve may be actuated through a pulley C, fixed upon the valve spindle,
Figures 2, 10 and 13, by means of a steel band or strap D'D' passing around it,
The two ends of this band are connected with an adjusting screw E, to take up
any stretch, for example, as shewn by Figure 10, by means of loops on the band
ends, passing over a pin t in the arm t¹ pivoted at and attached to the adjusting
screw E. Between the ends at t, and the pulley C, the two parts of the band pass
either around two excentrics, or preferably, and as shewn by Figure 10, around
two curved arms FFI mounted upon and operated by the two excentrics GG¹
on the crank shaft H. These excentrics are mounted at an angle of 180 deg.,
and by their action, whilst one part of the band is pulled the other part is allowed
to follow. The two parts of the band being thus alternately pulled, oscillatory
motion of the valve ensues. The band is always in tension and may be tightened
when the engine is in motion, by means of the hand wheol E', when necessary.
There may be arranged, in connection with the valve pulley C, an air buffer
on the dash-pot principle, as illustrated by Figuros 13 and 14. The function of
this appliance is to gradually arrest the motion of the valve at the end of each
oscillation by the compression of air, which compression is also utilised in facili-
tating the reversal of the valve motion. As shewn the buffer consists of a shallow
cylinder I, concentric with the valve spindle V, 'in which oscillata the two
wings which project from the inner face of the flanged pulley C. These wings
are 180 deg., apart and have between them the fixed wings or abutments JJ¹
which have radial faces. With this arrangement, as the pulley wings cc approach
the fixed wings JJ', first on one side and then on the other, the air between them
becomes gradually more and more compressed, and the reverse. Openings ii may
or may not be formed in the walls of the cylinder for air renewal. In the con-
struction shewn by the Figures 13 and 14, the steam is admitted through K to
the valve chest K at the back of the cylinder I, and the joint at K2 may be made
tight by any suitable packing. At the opposite end, a blank flange L may have
an internal boss bored to carry the end of the valve spindle.
The connecting rod M is attached to a trunk N, and the trunk to the piston B.
Around the trunk there is an annular chamber 0 which has steam admitted to
it through the opening or channel 01 during the time that the engine is running.
This annular chamber communicates by small openings o with the interior of the
trunk and the piston, so that the latter is internally steam jacketed. The steam
within the chamber O acts as a cushion and keeps the connecting rod in tension
during the exhaust stroke of the piston B.
In the position illustrated in Figure 1 the piston has reached the end of its
power stroke and the exhaust is about to commence. The valve has already
closed the steam inlet p, and its further movement in the direction of the hands
of a clock causes the exhaust channel in the valve to come into communication
with the exhaust port pl of the cylinder and permits the steam to pass through
the pipe or channel P whence it may be conducted to the atmosphere or to a
condenser or to a cylinder working at lower pressure. At the end of the active
stroke the piston uncovers the openings 6 and admits some steam to the upper
side.
When the piston has reached the bottom of its stroke as shown by Figure 1*
the lower port n in the trunk casing has reached the steam admission port p and
the valve has moved to admit the steam and to close the exhaust. The steam
passes into the cylinder through the openings n¹ and the piston is moved upwards.
The movement of the piston cuts off the steam admission.

page_text: W is a tap or cock in the top of the cylinder through which lubrication may be
effected and which may be opened when the engine is started to prevent air
cushioning.
Figure 1 illustrates the position of the valve when the steam is being exhausted.
It will of course be perfectly evident that the mechanism illustrated in Figure 10
may he similarly employed to actuate valves having other than rotary motion.
For instance a slide or similar valve may be operated by being connected to a
crank upon the shaft of the pulley C which, of course, would then cease to be the
valve shaft, or, similarly, the pulley C may be a loose running pulley over which
the band D passes and the valve may be connected to the band at any suitable
point.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A. prime motor operated by expansive fluids having steam admitted on the
back stroke only; having a flexible connecting rod; and having an oscillatory
valve operated by a band and two excentrics; constructed and arranged sub-
stantially as hereinbefore described and as illustrated by the accompanying
drawings.
2. In prime motors actuated by expansive fluids a flexible connecting rod in
combination with a piston acted upon on the back stroke only; constructed and
arranged substantially as herein before described and as illustrated by the accom-
panying drawings.
3. In prime motors actuated by expansive fluids and having oscillatory valves,
a valve motion consisting of a pulley on the valve spindle; a band passing over
the pulley; two excentrics or excentric arms at 180 degrees on the crank shaft
over which the two parts of the band pass, and means for securing and adjusting
the ends of the band; constructed and arranged substantially as and for the
purpose hereinbefore described and as illustrated by the accompanying drawings.
4. In prime motors operated by expansive fluids and having an oscillatory
valve and valve motion as set forth in the last preceding claim, the combination
and arrangement with the valve and valve spindle of a buffer constructed and
acting substantially as hereinbefore described with reference to Figures 13 and 14
of the accompanying drawings.
6. A valve for steam engines, consisting of a shell mounted upon a suitable
spindle by means of an interposed spring, constructed and arranged substantially
as herein before described and as illustrated by the accompanying drawings.
6. In a prime motor, the combination of a hollow piston, a connected trunk, a
steam chamber surrounding the trunk, and openings or passages by means of
which steam may pass from the chamber to the interior of the piston, all con-
structed and arranged substantially as hereinbefore described and as illustrated
by the accompanying drawings.
7. In a prime motor operated by expansive fluids, a valve motion consisting
of a band which passes over two excentrics or the like and to which the valve to be
operated is connected, substantially as hereinbefore described.
Dated this 6th day of November A.D. 1897
Dated this 6th day of November A.D. 1897
W. E.: HEYS & SON,
Agents for the Applicants.