Improvements in or applicable to Steam and other Engines.
Year: 1898

page_text: Improvements in or applicable to Steam and other Engines.
I, THOMAS ROLAND WOLLASTON, of Lyndale, Grange Road, Bowdon, in the
County of Chester, Engineer, do hereby declare the nature of this invention
to be as follows:-
-
The improvements which constitute my invention relate to single or multiple
cylinder engines whether simple, high pressure, or compound. The valves con-
trolling the steam distribution are cylindrical and rotating their rotation being
synchronous with that of the crank shaft from which motion is derived by a
pitch chain and sprocket wheels or the like. The valves rotate in suitably pre-
pared chambers preferably formed in the cylinder covers, as by this arrangement
the port clearance is reduced to a minimum, but the valve chambers may when
desirable be formed on the sides of the cylinders as for example in a similar
manner to that adopted in the well known Corliss type of engine. When used
for single acting two cylinder compound engines, in which the steam is
admitted on the upper side or in stroke of the pistons only, one valve controls
the distribution of steam to both cylinders, suitable passages and ports being
formed in the valve and valve chamber respectively which, as the valve rotates,
successively make communication between the steam supply and the high pres-
sure cylinder, the high pressure and the low pressure cylinder, and the low
pressure cylinder and the exhaust outlet. It is obvious that the same arrange-
ment may with suitable modifications be extended to serve in a similar manner
for engines of the three stage or four stage compound type. When used for
double acting engines taking steam alternately on each side of the pistons two
valves are used, one for each end of the cylinders. In order to prevent leakage
of steam from the inlet end to the low
pressure passages or to
the exhaust end of the valve chamber I reduce the diameter of both
the valve and the chamber between each successive cylinder SO as
to form a collar and shoulder respectively, the larger diameter being towards the
end of the valve chamber to which high pressure steam is admitted; there is
thus always a tendency to maintain tight contact between the collar and the
shoulder, but in order that the pressure between these contact surfaces may not
be so great as to set up undue frictional resistance I make provision by means of
a relief screw, or relief spindle and spring of ordinary well known type, for ad-
justing at the low pressure or exhaust end.
With the aforementioned type of valve the speed of an engine under varying
loads is controlled either by a throttling device or by a cut-off operated auto-
matically.
The throttling device is substantially equivalent to an ordinary throttle valve
working within the valve chamber. It consists of a cylindrical or piston type
of valve, mounted concentrically with and loosely upon the valve spindle, which
works over suitable ports in the inlet end of the valve chamber under the influence
of an ordinary spring loaded centrifugal governor which is mounted directly upon

page_text: the outer end of the valve spindle and revolves with it. The throttle valve slides
in the direction in line with the valve's axis as it covers and uncovers the ports,
and the communication between it and the governor is obtained by a rod which
passes through the hollow valve spindle.
The automatic cut-off device somewhat resembles the above, but in place of a
governor designed to give a longitudinal or sliding motion to the communication
rod within the valve spindle I use one of the well known drum type which causes
the communication rod to rotate with reference to the valve spindle, and so alters
the angular position of the cut-off valve with reference to the main valve under
varying loads, causing the steam supply to be cut off earlier during the stroke if
the engine over runs its normal speed or later if it runs too slowly.
For single acting engines I use an improved form of piston which may be de-
scribed as follows:-
The pistons are of comparatively great depth so as to act as their own guides
within the cylinders. They are bored through at right angles to their axes, and
pins of length somewhat shorter than the diameter of the pistons are fitted into
the holes thus formed. At the middle of their length these pins are bored and
tapped with a suitable screw thread to receive the inner ends of the connecting
rods. The pistons, which are so formed as to clear the connecting rods as they
vibrate, are fitted with the usual packing rings. At each end of the holes or
bearings which carry the pins in the pistons I provide plugs or stoppers to prevent
leakage of steam from the interior of the cylinder past the pins, or side play of
the pins when working. These plugs are preferably held in position by a bolt
passing through them and through the centre of the pins. The plugs are suit-
ably recessed for the purpose. In small engines the plugs may be simply screwed
in and the bolt be dispensed with.
In connection with engines in which the frame is so constructed as to form an
enclosed chamber in which the cranks work I form the frame in two pieces, the
division being on or near a plane passing through the centre line of the crank
shaft. The two parts of the frame are fitted with flanges or lugs suitable for bolting
together. The joints of the two pieces are not however faced but I cast one with
a projecting ridge all round and form a suitable recess to receive it in the other.
This recess is partly filled with packing or jointing material, such as asbestos,
upon which the ridge is clamped to form a tight joint. Twined steps for the
crankshaft bearings are fitted into suitable bored holes in the frame and two or
more holes are bored transversely through the joint and fitted with turned bolts.
The crank shaft steps and the turned bolts thus form points of metallic contact
between the two pieces of the frame, keeping them rigidly in their correct re-
spective positions the one to the other. I provide a bead or fillet upon one of the
pieces of the frame which overlaps the joint and improves the appearance of the
engine.
Although for the purpose of description I have herein referred to my said inven-
tion in its application to an engine operated by steam pressure it is to be under-
stood that it is in no wise confined to such but is also applicable to other fluid pres-
sure motors.
10.41 in 92nd dow of Vorob 1808
Improvements in or applicable to Steam and other Engines.
I, THOMAS ROLAND WOLLASTON, of Lyndale, Grange Road, Bowdon, in the 50
County of Chester, Engineer, do hereby declare the nature of this invention

page_text: and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
The improvements which constitute my invention relate to single or multiple
cylinder engines whether simple, high pressure or compound. The valves for instance
controlling the steam distribution are cylindrical and rotating, their rotation being
synchronous with that of the crank shaft from which they derive motion by a
pitch chain and sprocket wheels or the like means. The valves rotate in suitably
prepared chambers preferably formed in the cylinder covers, as by this arrangement
the port clearance is reduced to a minimum, but the valve chambers may when
desirable be formed on the sides of the cylinders, as for example in a similar
manner to that adopted in the well known Corliss" type of engine. When used
for single acting two cylinder compound engines, in which the steam is
admitted on the upper side or "in" stroke of the pistons only, one valve controls
the distribution of steam to both cylinders, suitable passages and ports being
formed in the valve and valve chamber respectively which, as the valve rotates,
successively make communication between the steam supply and the high pres-
sure cylinder, the high pressure cylinder and the low pressure cylinder, and the low
pressure cylinder and the exhaust outlet. It is obvious that the same arrange-
ment may with suitable modifications, be extended to serve in a similar manner
engines of the three stage or four stage compound type. When used for
double acting engines taking steam alternately on each side of the pistons two
valves are used, one for each end of the cylinders. In order to prevent leakage
of steam from the inlet end to the lower pressure passage or to
the exhaust end of the valve chamber I reduce the diameter of both
the valve and the chamber between each successive cylinder so as
to form a collar and shoulder respectively, the larger diameter being towards the
end of the valve; chamber where high pressure steam is admitted; there is
thus always a tendency to maintain tight contact between the collar and the
shoulder, but in order that the pressure between these contact surfaces may not
be so great as to set up undue frictional resistance I make provision by means of
a relief screw, or relief spindle and spring of ordinary well known type for ad-
justing at the low pressure or exhaust end. With the aforementioned type of valve
the speed of an engine under varying loads is controlled either by throttling or
by a cut-off operated automatically. The throttling device is substantially
equivalent to an ordinary throttle valve working within the valve chamber.
It consists of a cylindrical or piston type of valve, mounted concentrically with
and loosely upon the main valve spindle, which works over suitable ports in the
inlet end of the valve chamber under the influence of an ordinary spring loaded
centrifugal governor which is mounted directly on the outer end of the valve
spindle and revolves with it. The throttle valve slides in a direction in line with
the valve's axis as it covers or uncovers the ports and the communication between
it and the governor is obtained by a rod which passes through the hollow valve
spindle. The "automatic cut off" device somewhat resembles the above but in
place of a governor designed to give a longitudinal or sliding motion to the com-
munication rod within the valve spindle I use one of the well known
drum"
type which causes the communication rod to rotate with reference to the valve
spindle and so alters the angular position of the cut off valve with reference to
the main valve under varying loads, causing the steam supply to be cut off earlier
during the stroke if the engine over-runs its normal speed or later if it runs too
slowly.
"
For single acting engines I use an improved type of piston which may be de-
scribed as follows:-
The pistons are of comparatively great depth so as to act as their own guides
within the cylinders. They are bored through at right angles to their axes and
pins of length somewhat shorter than the diameter of the pistons are fitted into
the holes thus formed. At the middle of their length these pins are bored and
tapped with a suitable screwthread to receive the inner ends of the connecting

page_text: rods. The pistons, which are so formed as to clear the connecting rod as it
vibrates, are fitted with the usual packing rings. At each end of the holes or
bearings which carry the pins in the pistons I provide plugs or stoppers to prevent
leakage of steam from the interior of the cylinder past the pins, or side play of
the pins when working. These plugs are preferably held in position by a bolt
passing through them and through the centre of the pins. The plugs are suit-
ably recessed for the purpose. In small engines the plugs may be simply screwed
in and the bolt be dispensed with. In connection with engines in which the frame
is so constructed as to form an enclosed chamber in which the cranks work I form the
frame in two pieces, the division being on or near a plane passing through the
centre line of the crank shaft. The two parts of the frame are fitted with flanges
or lugs suitable for bolting together. The joints of the two pieces are not how-
ever faced but I cast one with a projecting ridge all round, and form a recess to
receive it in the other. This recess is partly fitted with packing or jointing
material, such as asbestos, upon which the ridge is clamped to form a tight joint.
Turned steps for the crank shaft bearings are fitted into suitable bored holes in the
frame, and two or more holes are bored transversely through the joint fitted with
turned bolts. The crankshaft steps and the turned bolts thus form points of
metallic contact between the two pieces of the frame keeping them rigidly in
their correct respective positions the one to the other. I provide a bead or fillet
upon one of the pieces of the frame which overlaps the joint and improves the
appearance of the engine.
Although for the purpose of description I have herein referred to my said inven-
tion in its application to an engine operated by steam pressure it is to be understood
that it is in no wise confined to such but is also applicable to other fluid pressure
motors.
By reference to the accompanying drawings upon which Fig. 1 represents a
longitudinal section of a compound vertical single acting engine embodying the
herein before named improvements and Fig. 2 represents a cross section through
the larger cylinder of the same engine: A and B represent respectively the high
and low pressure cylinders (is the cylindrical rotating valve which in the position
shown would be passing steam or other fluid from the high to the low pressure
cylinder, but, if rotated through 180°, would obviously close the communication
between the two cylinders and open communication respectively between the inlet
branch and the cylinder A and also between the cylinder B and the exhaust
branch F.
1 is the cylindrical chamber prepared to receive the valve C. c is the shoulder
or collar formed on the valve and chamber respectively to prevent leakage.
66
drum"
governor in con-
G is an ordinary centrifugal governor which, when the normal speed is exceeded,
causes the throttle valve g to slide over the port through the agency of the rod p.
When a drum governor is used the rod and the valve g are caused to rotate with
reference to the valve spindles instead of sliding longitudinally the ports e and the
valve being suitably shaped to give the required range of "cut off."
Figs. 3, 4, 5 and 6 illustrate the application of a
nection with a rotating main valve of the type herein described.
Qon Figs. 3 and 6 respectively illustrate side and front elevations of the drum
governor. represents a double ended lever rigidly attached to the rod p.
Upon Fig. 6 the full lines shew the governor arms and the lever
g
in the
position in which they lie the one to the other when the engine is running at or
below its normal speed, while the dotted lines shew the arms and the lever q in
the position they assume the one to the other when the engine overruns its normal
speed.
On Fig. 4 and 5 the main valve spindle and the inlet port e are shewn in
exactly the same angular position the one to the other but the position of the cut
off valve g in Fig. 4 corresponds with the position of the lever q Fig. 6 as shewn in
full lines while the position of the valve g in Fig. 5 corresponds with that of the
lever q Fig. 6 as shewn in dotted lines.

page_text: It is thus obvious that with the governor as shewn in full lines on Fig. 6 the
admission port o may be open during the whole period that the main valve ad-
mission port is open while with the governor as shewn in dotted line the angular
position of the cut off valve g is advanced in relation to the main valve and may
be proportioned so as to close the port e before, at the time of, or soon after the
main valve admission port opens.
O is a relief screw for the purpose of regulating the pressure on the shoulder c.
H, H, are pistons fitted with pins I, I, which are bored and tapped to receive
the inner ends of the connecting rods L L.
J, J, are plugs or stoppers held in position by the bolts j j. K is the pitch chain
by which the valve C is rotated through the sprocket wheels kk.
M shews the joint in the frame having the recess and projection m formed upon
its two parts respectively for packing.
N is one of the turned bolts fitted into a hole, bored transversely through the
joint, forming one of the points of metallic contact between the two parts of the
frame.
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 steam or other engines the combination of cylindrical rotating valves
working within cylindrical chambers, driven synchronously with and from the
crank shaft by pitch chain or chains and sprocket wheels and provided with
shoulder, and relief screw or relief spindle and spring, substantially as and for
the purposes herein before described and as illustrated in the accompanying draw-
ings.
2. In combination with a rotating valve of the type named herein a throttle
valve, mounted upon and concentrically with the valve spindle and working over
ports in the inlet branch of the valve chamber and controlled by a spring loaded
governor, mounted directly upon the end of the hollow valve spindle, by means
of a rod passing through the said spindle, substantially as and for the purposes
herein before described and as illustrated in the accompanying drawings.
3. In combination with a rotating valve of the type named herein a cut off
valve mounted upon and concentrically with the valve spindle and working over
ports in the inlet branch of the valve chamber and controlled by a drum governor,
mounted directly upon the end of the hollow valve spindle, by means of a rod
passing through the said spindle, substantially as and for the purposes herein before
described, and as illustrated in the accompanying drawings.
4. In single acting engines pistons having pins fitted into bored holes provided
with plugs at each end, the pins being tapped at the middle of their length to
receive the inner ends of the connecting rods, substantially as and for the purposes
herein before described and as illustrated in the accompanying drawings.
5. In engines having an enclosed crank chamber formed in two pieces, a joint
formed by a flange on each, these having respectively a projecting ridge and a
recess for the reception of packing formed in them, and being provided with
turned steps and transverse bolts which form points of metallic contact between
hem, substantially as and for the purposes herein before described and as illus-
crated in the accompanying drawings.
02 1
1000