Improvements in Steam and other Fluid Engines and Pumps.
Year: 1896

page_text: Improvements in Steam and other Fluid Engines and Pumps.
I, HENRY MARTYN NICHOLLS, of 1034 Fulham Road, London S.W. Engineer,.
do hereby declare the nature of my said invention to be as follows:-
The leading object of this invention is to produce a steam engine capable of
giving a direct rotary motion to the engine shaft, and at the same time capable of
carrying out the expansive principle of using the steam in an effective manner.
The engine shaft passes through the centre of a suitably mounted cylinder,
fitted with covers at each end, in the centre of which are stuffing boxes to prevent
leakage. Fast on the engine shaft within the cylinder, and extending from cover
to cover, is an eccentric which serves as the piston. At the point of greatest
eccentricity the eccentric piston comes in contact with the interior circumference
of the cylinder, and at this point and also at both sides, where it is in contact with
the interior surface of the covers, it is caused to move steam tight by suitable
metallic packing. The engine shaft is carried in suitable bearings outside the
cylinder covers, in which it is free to revolve.
The steam is caused to act in the required manner on the eccentric piston by
means of a "steam stop," which is caused to enter the cylinder at one point in its
circumference through a slot extending from cover to cover parallel with the engine
shaft. A steam tight casing is attached to the same side of the cylinder, into
which the steam stop retreats as the eccentric piston moves round in the cylinder.
In the upper part of this casing a shaft is mounted parallel with the engine shaft
and free to turn in bearings. This shaft carries the steam stop which is fast
thereon. That part of the steam stop where it enters the cylinder is curved, the
curve being struck from the centre of the shaft which carries the steam stop. The
front edge of the steam stop is kept in steam-tight contact with the circumference
of the eccentric piston. The shaft which carries the steam stop is mounted in the
casing above and on one side of the centre of the cylinder; and the steam stop,
both where it is in contact with the piston, and on both sides, and underneath, is
caused to move steam-tight by suitable metallic packing.
The shaft which carries the steam stop passes out of one side of the casing
through a stuffing box, and its outer extremity is fitted with a lever fast thereon.
This lever at its lower extremity carries a pair of rollers which run in a groove
formed in the circumference of an eccentric fast on the engine shaft, outside one
of the bearings. The centre of the groove round this eccentric corresponds
exactly with the outer circumference of the eccentric piston, both as to diameter
and position on the shaft, so that, as this outer eccentric revolves with the shaft,
t gives the steam stop exactly the same motion as the eccentric piston.
The slot in the cylinder for the entry of the steam stop, allows also of the
passage of the steam into and out of the cylinder.
The lower part of the casing contains a three-ported slide valve and a cut-off
alve.
On the slide valve being moved so as to uncover the port, the steam enters
he cylinder, passing in underneath the steam stop and pressing on the piston,
nd so turning the engine shaft in the direction the engine is required to run.
On the eccentric piston completing the revolution, the steam exhausts into the

page_text: upper part of the casing, from which it passes through the slide valve to the
condenser or the atmosphere.
If worked expansively the cut-off valve is caused, by a suitable cam-movement,
to cut the steam off at any desired point in the revolution of the piston.
If the engine is reversed the other steam port is opened, and steam fills the
upper part of the casing, from which it can enter the cylinder by passing in
above the steam stop, and exhausting from the underside.
If a single engine is employed a fly-wheel is fitted, to equalise the motion,
and balance the eccentric piston.
If two engines are employed, both turning one shaft, the eccentric pistons are
fixed on opposite sides of the shaft.
A
1000
COMPLETE SPECIFICATION.
Improvements in Steam and other Fluid Engines and Pumps.
I, HENRY MARTYN NICHOLLS, late of 103ª Fulham Road, London S. W., but
now of 187 Earl's Court Road, London S.W., Engineer, do hereby declare the
nature of my said invention and in what manner the same is to be performed, to.
be particularly described and ascertained in and by the following statement :-
The object of my invention is to effect improvements in steam and other fluid
engines and pumps, in which a direct rotary motion is imparted to the main shaft
by the pressure of the fluid, when used as a motor, with means for applying the
expansive principle of working.
And in order that my said invention may be particularly described and ascer-
tained, reference is hereby made to the accompanying drawings, in which similar
figures of reference indicate corresponding parts.
Fig. 1 is an elevation, partly in section, and Fig. 2 is a horizontal plan, also
partly in section.
The main casting of the engine, 3, consists of the framing, cylinder, passages,.
and valve box, to which the casting 4, containing the valve seat and remaining
passages, is bolted. 5 is a cover to the main casting. 6 is the driving shaft
which passes through the centre of the cylinder, and through stuffing boxes 7, 7,
in the covers 8, 8, and is suitably mounted in external bearings 9 and 91.
The cylinder is truly bored, and the inner surfaces of the covers are faced, so
as to provide suitable steam-tight contact surfaces for the piston 10, which is
mounted, eccentrically, fast upon the shaft 6. At the point of greatest eccentricity
the piston 10 is fitted with metallic packing 11, to prevent the leakage of steam or
other fluid, where it is in contact with the internal surface of the cylinder; and
the ends of the piston are similarly packed at 12, 12, where they are in contact
with the internal surfaces of the covers 8, 8; as shown by dotted lines in Fig. 2.
The steam is caused to act in the required manner upon the eccentric piston, by
means of the steam stop 16 consisting of a segmental plate attached to arm 13 fast
on a shaft 14, the latter being free to turn in bearings in the framing 3. One end
of the shaft 14 passes steam-tight through a stuffing box 17, and carries an arm or
lever 18 fast thereon. The outer extremity of this arm 18 is geared with an
eccentric 19, fast on the main shaft 6, just outside the bearing 9.
The end of the segment 15 is thus kept in constant contact with the piston 10.
The segment 15, is packed at 16 radially, and also with end packings to prevent the
escape of steam or other fluid.
The slide valve 20 is actuated by the spindle 21, the outer extremity of the
spindle being supported free to turn in the frame of the engine. Just outside

page_text: the engine frame the spindle 21 carries the starting lever 22. The cut-off valve 23
is actuated by the spindle 24, the spindle being supported by the frame of the
engine, the outer end being fitted with a crank by means of which it is geared with
one of the cams 25 or 26, fast on the main shaft 6, just outside the bearing 9.
Both valves are operated in the usual and well known manner.
The following is the method of operation, when used as a steam engine:-
Steam being turned on to the valve box, and the slide valve 20 being in the
position shown in Fig. 1 (but with the expansion valve open) the steam passes in
the direction indicated by the arrows, and acting on the eccentric piston 10, causes
the revolution of the main shaft 6, in the direction the engine is required to run,
the eduction steam exhausting, as also shown by the arrows, into the exhaust
passage 27. The action of the eccentric 19, meanwhile, on the steam stop 15,
causes the latter constantly to follow the movements of the eccentric piston, the
metallic packing 16 keeping it steam tight in all positions.
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. The improvements in steam and other fluid engines and pumps, substantially
as herein before described and illustrated by the drawings.
2. In a rotary engine as aforesaid, the combination with an eccentric piston fast
on the main shaft, of a segmental steam stop retained in contact with the eccentric
piston by means of an eccentric fast on the shaft and suitable intermediate
connecting gear, with slide valves and other ordinary gear, all operating
substantially as herein before described and illustrated by the drawings.
Dated 28th October 1896.
GEO.
DOWNING,
8 Quality Court, London, W.C., Agent.