Improvements in Steam Engines.
Year: 1898

page_text: Date of Application, 14th Sept 1808
Complete Specification Left, 14th June, 1899-Accepted. 14th Sept., 1899
Complete Specification Left. 14th June, 1899-Accepted. 14th Sept., 1899
PROVISIONAL SPECIFICATION.
Improvements in Steam Engines.
I, JAMES THOMAS ROSSITER, of Tynwald, Grove Park Road, Chiswick, in the
County of Middlesex, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to a construction of single acting compound
engine wherein the admission and exhaust of high pressure steam to and from
the upper or outer end of the high pressure cylinder and the passage of such
steam from that end of the cylinder to the opposite end thereof, to the upper or
outer end of the low pressure cylinder and to an exhaust pipe is controlled by
two separate valves arranged with their axes at right angles to the axes of the
cylinders and one of which, viz. the high pressure valve, is driven and controlled
by a drum or other suitable form of expansion governor on the engine crank
shaft, and the other or low pressure valve is driven and controlled by an eccen-
tric on such shaft. The valves may be arranged to slide endways or to rotate.
According to one construction, the high and low pressure cylinders are arranged
vertically one above the other with a receiver between them, the high pressure
cylinder being uppermost and provided at its upper end with a cylindrical valve
box which has one end in cominunication with a high pressure steam inlet, and
the other end through a vertical pipe or passage with a low pressure valve box
one end of which communicates with the lower end of the high pressure cylinder
through the receiver and the other end with the lower end of the low pressure
cylinder and with an exhaust branch through a steam chamber arranged at the
side of the low pressure cylinder, the lower end of this cylinder being arranged
to drain into such chamber and exhaust branch.
or
with
projections
grooves
or
The high pressure valve is of the piston type arranged to slide endways in the
high pressure valve box and control two ports or sets of ports in the top of the
high pressure cylinder. It may advantageously be formed with three external
annular ribs
intermediate annular
recesses one of which communicates through an opening in the valve
with the exhaust end of the valve box and the other of which is in
constant communication with a high pressure steam inlet port arranged between
the ends of the box. The arrangement is such that when the valve is moved
endways in one direction sufficiently to uncover one port or set of ports, high
pressure steam will enter such port or ports from one end of the valve box and
will also enter the other port or set of ports through the annular passage around
the valve, and when the valve is moved in the opposite direction sufficiently to
uncover the second port or set of ports, steam will exhaust through such port or
ports direct and also through the first port or set of ports and the valve."
high pressure valve rod extends through a stuffing box and is worked from a
drum governor, as for example through a rod and bell crank lever.
The
The low pressure valve is of the piston type arranged to slide in a cylindrical
valve box. It is made hollow and divided internally by a transverse division

page_text: into two parts one of which communicates with the steam receiver and the other
with the exhaust chamber. The periphery of the valve is also divided into two
parts by an annular opening or ring of holes which communicate with the receiver
through the inner portion of the valve, one part of the said peri-
phery controlling an annular surrounding groove or
communicating with the pipe or passage leading to the exhaust end of the high
ring of ports
pressure valve box and the other part of the periphery of the valve controlling
a port or set of ports leading to the top of the low pressure cylinder. The
arrangement is such that when this valve is moved in one direction, it permits
steam to exhaust from the high pressure cylinder into the receiver only at the
proper time, and notwithstanding that the high pressure valve may have already
placed the top of the high pressure cylinder in communication with the exhaust
end of the high pressure valve box, and also places the top of the low pressure
cylinder in communication with the exhaust chamber, thereby placing the high
and low pressure pistons nearly in equilibrium and enabling them to make their
return stroke under advantageous conditions. On moving the low pressure valve
in the opposite direction, the communication between the top of the low pres-
sure cylinder and the exhaust chamber is first closed and that between the steam
receiver and cylinder opened at the time when high pressure steam is admitted
to the high pressure cylinder, the high and low pressure pistons then making
their down strokes together. The low pressure valve rod is worked through a
lever and rod from an eccentric on the crank shaft which may work in a closed
chamber.
In a modified construction, two engines of the kind hereinbefore described are
arranged side by side with the two pairs of pistons working onto oppositely
arranged cranks on a common shaft, the two high pressure valves being con-
nected and worked together by a rod common to them, as also are the two low
pressure valves, and the drum governor and eccentric being arranged on the crank
shaft between the two cranks with their operating rods and levers between the
pairs of cylinders which may be mounted on a closed crank chamber. If the
relative valves are of the same diameters they will be approximately balanced
for steam pressure, but by making one larger than the other the steam pressure
will give them a constant thrust in one direction and thereby prevent any back-
lash in the working parts.
As will be obvious the details of construction can be variously modified.
Thus the valve rods may be placed to one side of the axes of the cylinders and
be controlled from a governor and eccentric on one end of the shaft and external
to the crank chamber, when such is used.
being arranged vertically, may be otherwise arranged, for example horizontally.
The engine or engines instead of
Dated this 14th day of September 1898
I, JAMES THOMAS ROSSITER, of Tynwald, Grove Park Road, Chiswick, in the
County of Middlesex, 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 has reference to a construction of single acting.
1

page_text: engine wherein the admission and exhaust of high pressure steam to and from
the upper or outer end of the high pressure cylinder and the passage of such
steam from that end of the cylinder to the opposite end thereof, to the upper or
outer end of the low pressure cylinder and to an exhaust pipe is controlled by
two separate valves arranged with their axes at right angles to the axes of the
eylinders and one of which, viz. the high pressure valve, is driven and controlled
by a drum or other suitable form of expansion governor on the engine crank
shaft and the other or low pressure valve is driven and controlled by an eccen-
tric on such shaft. The valves may be arranged to slide endways or to partly
rotate.
Fig. 1 of the accompanying illustrative drawings shows in central vertical
section one construction of single acting compound engine according to this inven-
tion. Figs. 2, 3 and 4 are horizontal sections on the lines A B, C D and EF
respectively of Fig. 1.
In this example the high and low pressure cylinders 1 and 2 respectively are
arranged vertically one above the other with a receiver 3 between them. The
high pressure cylinder 1 is uppermost and is provided at its upper end with a
cylindrical valve box 4 which has one end in communication with a high pres-
sure steam inlet 5, and the other end through a vertical pipe or passage, or, as
in the example shown through two vertical pipes or passages 6, with a low pres-
sure valve box 7 one end of which communicates with the lower end of the high
pressure cylinder 1 through the receiver 3 and the other end with the lower end
of the low pressure cylinder 2 and with an exhaust branch 8 through a steam
chamber 9 arranged at the side of or around the low pressure cylinder, the lower
end of this cylinder being arranged, as shown, to drain into such chamber and
exhaust branch.
The high pressure valve 10 is of the piston type arranged to slide endways in
the high pressure valve box and control two ports or sets of ports 11, 11 in
the top of the high pressure cylinder. It may advantageously be formed, as shown,
with three external annular ribs or projections 10" with intermediate annular
grooves or recesses one of which, viz. 10b, communicates through an opening or
passage 10° in the valve with the exhaust end of the valve box, and the other of
which, viz. 10, is in constant communication with a high pressure steam inlet
port 5ª arranged between the ends of the box. As will be seen the arrangement
is such that when the valve 10 is moved endways in one direction, riz. to the
right, in the example shown, sufficiently to uncover the port or set of ports 11,
high pressure steam will enter such port or ports from one end of the valve box
and will also enter the other port or set of ports 11" through the annular pas-
sage 10 around the valve, and when the valve is moved in the opposite direction,
riz. to the left, sufficiently to uncover the second port or set of ports 11ª steam
will exhaust through such port or ports direct and also through the first
port or set of ports 11 and the opening 10° in the valve. The high pressure
valve rod 12 extends through a stuffing box 13 and is worked from a drum
governor 14, as for example, through a rod 15 and bell crank lever 16.
The low pressure valve 17 is of the piston type arranged to slide in a cylin-
drical valve box 7. It is made hollow and divided internally by a transverse
division 17 into two parts one of which, riz. the inner part, communicates with
the steam receiver 3 and the other, viz. the outer part, with the exhaust
chamber 9. The periphery of the valve is also divided into two parts by an
annular opening or ring of holes 18 which communicate with the receiver 3
through the inner portion of the valve, one part of the said periphery riz. the
inner part controlling an annular surrounding groove or ring of ports 19 com-
municating with the pipe or passage or pipes or passages 6 leading to the
exhaust end of the high pressure valve box 4 and the other part of the periphery
of the valve controlling a port or set of ports 20, leading to the top of the low
pressure cylinder. As will be seen the arrangement is such that when the said
low pressure valve is moved in one direction, viz. to the left in the example

page_text: shown, it permits steam to exhaust from the high pressure cylinder through
the passages 6, groove or ports 19 and opening or holes 18 into the receiver 3
only at the proper time, and notwithstanding that the high pressure valve 4 may
have already placed the top of the high pressure cylinder 1 in communication
with the exhaust end of the high pressure valve box the valve also placing the
top of the low pressure cylinder 2 in communication through the ports 20 with
the exhaust chamber 9 and the lower end of the low pressure cylinder, thereby
placing the high and low pressure pistons 21 and 22 nearly in equilibrium and
enabling them to make their return or upstroke under advantageous conditions.
On moving the low pressure valve in the opposite direction, viz. to the right, the
communication between the top of the low pressure cylinder 2 and the exhaust
chamber 9 is first closed and that between the steami receiver 3 and low pres-
sure cylinder 2 opened at the time when high pressure steam is admitted to the
high pressure cylinder 1, the high and low pressure pistons 21 and 22 then
making their down strokes together. The low pressure valve rod 23 is worked
through a lever 24 and rod 25 from an eccentric 26 on the crank shaft 27 which
may, as shown, work in a closed or practically closed chamber 28.
Fig. 5 shows in vertical section, a modified construction wherein two engines
of the kind hereinbefore described are arranged side by side with the two pairs of
pistons 21 and 22 working onto oppositely arranged cranks 27" on a comnion
shaft 27, the two high pressure valves 10 being connected and worked together
by a rod common to them, as also are the two low pressure valves 17, and the
drum governor 14 and eccentric 26 being arranged on the crank shaft between
the two cranks with their operating rods 15 and 25 and levers 16 and 24 between
the pairs of cylinders 1 and 2.which may be mounted on a closed or practically
closed crank chamber 28. If the two high pressure valves 10, or the two low
pressure valves 17 are made of the same diameters they will be approximately
balanced for steam pressure, but by making one larger in cross sectional area
than the other the steam pressure will give them a constant thrust in one direc-
tion and thereby prevent any backlash in the working parts.
Figs. 6 and 7 are vertical sections at right angles to one another showing a
modified arrangement of engines of the kind hereinbefore described wherein the
high and low pressure valves are arranged to partly rotate instead of to slide.
The two high pressure valves 10 are connected together and worked by a rod 12
common to them, as also are the two low pressure valves 17 by a rod 23, the
two rods 12 and 23 being formed with cranked portions 12 and 3, respectively
that are connected by eccentric rods to the corresponding eccentrics on the crank
shaft. The exhaust passages 6 and 9 in this arrangement are arranged at the
front of the right hand engine and on the back of the left hand engine so that
although the two valves 10 and also the two valves 17 are rigidly connected to
common rods 12 and 23 respectively and are actuated from the same crank shaft,
the motion of the valves in one engine will be opposite to that of the valves in
the other engine, thus enabling the pistons of one engine to make their up-
stroke whilst the pistons of the other engine are making their down stroke.
The valves may conveniently be of the Corliss or Wheeloch type.
As will be obvious the details of construction can be variously modified. Thus
the valve rods may be controlled from a governor and eccentric on one end of the
shaft and external to the crank chamber when such is used. The engine or
engines instead of being arranged vertically, may be otherwise arranged, for
example horizontally.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
-
1. A single acting compound engine comprising a high pressure cylinder and
a low pressure cylinder arranged in tandem. a steam receiver located between
the adjacent ends of the cylinders, a valve chest at the outer and of the high

page_text: pressure cylinder, an exhaust passage whereby steam can pass from the outer
end of the high pressure cylinder into the said receiver, a valve located in the
said valve chest and adapted to place the outer end of the high pressure cylinder
alternately in communication with a high pressure steam supply opening and
with the said steam passage, a second valve chest, a second exhaust passage
extending from the second valve chest and in communication with the inner end
of the second cylinder and with an exhaust pipe, a second valve
located in the second valve chest and adapted to place the outer
end of low pressure cylinder alternately in communication with the said
receiver and the second exhaust pipe, and means for operating the said valves,
all substantially as herein described with reference to the drawings annexed.
2. A single-acting compound engine comprising two sets of cylinders, receivers,
steam passages and controlling valves arranged separately as specified in the
preceding claim, the two high pressure valves and also the two low pressure
valves being connected together and made of unequal cross sectional area so that
a constant thrust in one direction is imparted to each set of valves and backlash
in the working parts prevented, substantially as described.
3. The improved single-acting compound steam engines constructed, arranged
and operating substantially as herein before described with reference to and shown
in Figs. 1 to 4 inclusive, in Fig. 5, and in Figs. 6 and 7 of the drawings annexed.