IMPROVEMENTS. IN COMPOUND STEAM ENGINES
Year: 1877

page_text: LETTERS PATENT to Albion Vile, otherwise known as Albert Vile, of the Town
and County of the Town of Southampton, for the Invention of "IMPROVEMENTS.
IN COMPOUND STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said Albion Vile at the Office of
the Commissioners of Patents on the 13th October 1877.
ALBION VILE otherwise known as ALBERT VILE of the Town and County of the
Town of Southampton. "IMPROVEMENTS IN COMPOUND STEAM ENGINES.'
My Invention relates to improvements in compound engines of that kind in
which the piston of the high-pressure cylinder is made to act as the valve to open
and close the ports leading from the high-pressure cylinder to the low-pressure
cylinder or cylinders for controlling the passage of steam from the one to the other..
The steam after it has acted on the piston of the high-pressure cylinder is passed
directly into the low-pressure cylinder or cylinders without the intervention of any
slide valve between the cylinders and without exhausting into jackets or receivers
of any kind. And my Invention consists more particularly in exhausting directly from
both ends of the high-pressure cylinder to the condenser or atmosphere in order to
avoid compression or back pressure in the said cylinder. For this purpose I provide
exhaust valves in connection with ports leading from the ends of the cylinder, the
valves being connected together and worked through a link motion or in engines
which do not require reversing directly by eccentrics or otherwise. These valves
are preferably blank valves, that is to say solid plates or pistons without any
exhaust cavity in them.
I also provide a similar arrangement of valves for the low-pressure cylinder.
Between the cylinders I provide reversing valves, which, as well as the ports which
they control, are so arranged as to leave no vacant spaces in which the steam can
Prins 671

page_text: expand uselessly in passing from the one cylinder to the other. Each consists of a
hollow cylinder closed at one end and fitting like a piston in another and rather longer
cylinder, the steam when the engine is going ahead, passing from the high-pressure
cylinder to the corresponding ends of the low-pressure cylinder over the ends of the
valve. When the engine is reversed by shifting the valves, the steam passes through
the interior of the valves which then place the opposite ends of the cylinders in
communication. The slide valve in the high-pressure engine is an equilibrium
valve.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Albion Vile in the Great Seal Patent Office on the 12th April
1878.
ALBION VILE otherwise known as ALBERT VILE, of the Town and County of the
Town of Southampton. "IMPROVEMENTS IN COMPOUND STEAM ENGINES."
My Invention relates to improvements in compound engines of that kind in which
the piston of the high-pressure cylinder is made to act as the valve to open and
close the ports leading from the high-pressure to the low-pressure cylinder or
cylinders for controlling the passage of the steam from the one to the other. The
steam after it has acted on the piston of the high-pressure cylinder is passed directly
into the low-pressure cylinder or cylinders, without the intervention of any slide
valve between the cylinders and without exhausting into jackets or receivers of any
kind. And my Invention consists more particularly in exhausting in such an engine
directly from the ends of the high-pressure cylinder to the condenser or atmosphere
in order to avoid compression or back pressure in the said cylinder. For this pur-
pose I provide exhaust valves in connection with ports leading from the ends of the
cylinder, the valves being connected together and worked through a link motion or
directly by eccentrics or otherwise, in engines which do not require reversing. These
valves are preferably blank valves, that is to say, solid plates or pistons without any
exhaust cavity or passage in them.
I also provide a similar arrangement of valves for the low-pressure cylinder.
Between the cylinders I provide reversing valves, which, as well as the ports they
control, are arranged in a peculiar manner and so as to leave no vacant spaces in
which the steam can expand uselessly in passing from the one cylinder to the other.
Each consists of a hollow cylinder closed at one end and fitting like a piston in
another and rather longer cylinder, the steam, when the engine is going ahead,
passing from the bigh-pressure cylinder to the corresponding ends of the low-
pressure cylinder over the ends of the valve. When the engine is reversed by
shifting the valves, the steam passes through the interior of the valves which then
place the opposite ends of the cylinders in communication. The slide valve which
controls the admission of steam to the high-pressure engine is an equilibrium
valve.

page_text: DESCRIPTION OF DRAWINGS.
Figure 1 is a vertical section of a compound engine as described, the section
being taken on a line passing through the axis of the reversing valve El as at
1-1 Figure 2, which is a horizontal section of the same taken on a line 2-2
Figure 1.
Figure 3 is a vertical section of the reversing valves on line 3-3 Figure 2,
looking towards the cylinder A; and Figures 4 and 5 are horizontal sections of the
reversing valves and the ports in connection therewith, taken on the lines 4-4, 5-5
Figure 1 respectively.
Figure 6 shows one arrangement of gear that may be used in connection with the
exhaust valves of the low-pressure cylinder, that for the same valves of the high-
pressure cylinder being similar.
Figure 7 is a part sectional elevation of an engine without reversing valves.
A a are the high-pressure cylinder and piston, and B b are the low-pressure
cylinder and piston. Ĉ is the steam valve controlling the admission of steam through
the ports c to the high-pressure cylinder. D D₁ are the ports leading from
cylinder A to the reversing valves E.E', and d d¹ dd³ are ports leading from the
latter to the cylinder B. F are the exhaust valves of both cylinders.
The steam valve C is an equilibrium valve, being fitted to work between its seat
and an accurately planed surface at its back on the cover of the valve chest, as
shown; and it is also a blank valve, that is to say, without any exhaust cavity or
passage in it. Its weight and size are thus reduced to less than half of the
weight and size of the slide valves commonly in use, and having no exhaust passage,
it can be linked up to any required degree of expansion without causing compression
as the exhaust takes place when the separate exhaust valves F open.
The piston a is of considerable thickness, being preferably equal to the length of
its stroke and therefore equal to half the length of its cylinder A, and it acts as a
valve for controlling the admission of steam to cylinder B. The piston a is prefer-
ably of the same weight as the piston b, so that the pistons are balanced.
The ports and reversing valves connecting cylinder A to cylinder B are
arranged as follows. From the upper end of cylinder A, a port D leads directly
into the adjacent end of the casing of the reversing valve E as shown in
Figures 3 and 4, and from the lower end of cylinder A another port D¹ leads
similarly into the casing of the other reversing valve E', as shown in Figures 13
and 5.
dd Figures 1 and 4 are ports leading from the upper ends of the two reversing
valve casings into the upper end of the cylinder B where they meet in a single
orifice, and d d Figures 1 and 5 are similar ports connecting the lower ends of
the two reversing valve casings with the lower end of cylinder B.
The valves E E¹ are of cylindrical or other form in cross section, and are fitted
steam-tight in corresponding cylinders or chambers E' in one with the cylinders A
and B or otherwise. These chambers E³ are rather longer than the valves E E¹, so
as to leave a passage for the steam past the ends of the valves, which, when the
engines are working ahead, are in the positions shown at Figure 3, the valve E
being at the bottom and valve E' at the top of its chamber. Each valve is hollow
or tubular and open at one end and closed at the other, the valve E being open
at bottom and closed at top, and the valve El closed at bottom and open at top.
At the side and near the closed end of each valve there is a port e, which, when
the position of the valves is reversed coincides with the corresponding port leading
from the cylinder A and the steam instead of passing the ends of the valves then
passes through the hollow valves to the opposite ends of the cylinder B.
The valves E E' are attached to rods passing through stuffing boxes in the covers
of the chambers and connected to rock levers E³, Figure 3 coupled so that the two
valves are moved simultaneously in opposite directions when the engine is reversed,
these rock levers being operated by hand or connected to the same weigh shaft as

page_text: the link motions of the exhaust valves F hereafter referred to. F are.the exhaust
valves, one for each end of each cylinder, and fare the exhaust ports, those of the
cylinder A entering the cylinder at the same orifices as the steam ports c. These
valves are blank valves, that is to say, without any exhaust cavity in them, the
exhaust steam passing the end of the valve on its way to the exhaust pipe.
The valves F are shown as being flat plates, but they might be cylindrical
pistons. In either case they are fitted to work in chambers of corresponding form F'
against a suitable seat provided with a port f' leading to a receiver, to which the
exhaust pipe is attached, as shown.
By the use of blank exhaust valves separate from the steam valve and from one
another, the friction of the exhaust valves against their seats is greatly reduced,
thereby admitting of a greater pressure of steam than is at present practicable with
the ordinary arrangement of valves. These valves are attached to valve rods
passing through stuffing boxes and are preferably coupled in pairs by being attached
to cross heads connected by rods forming a frame G, as shown in Figure 6, sliding in
guides g and connected, each frame to a link motion H operated by eccentrics on
the crank shaft in the usual manner. The links of both pairs of exhaust valves are
also preferably connected to the same weigh shaft as the reversing valves E, as above
mentioned, so that all these valves are shifted at once when the motion of the
engine is to be reversed.
The working of the engine is as follows:-The parts being in the position shown
and the pistons moving in the direction of the arrows, steam is being admitted to
the top sides and exhausted from the bottom sides of both pistons. The steam
having at first acted on the top side of piston a only, when the latter arrived at the
middle of its stroke (the position shown) it uncovered the port D and admitted the
steam directly through that port, over the end of valve E, and through port d to the
top side of piston b. On or before the closing of port D₁ by the other side of
piston a, the exhaust valves opened at the lower ends of both cylinders. Similarly
on the return stroke, when the piston a has been raised by the steam acting on its
lower face to the same position (the piston b being now at the bottom of its
cylinder) thereby uncovering the port D¹, the steam passes directly under the
valve E¹ through port d¹ to the lower side of piston b. The steam admitted to
cylinder A thus acts as motive power in both cylinders in the same direction, there
being no exhaust jackets, receivers, or spaces where steam can expand uselessly.
When the valves E El are reversed, as above described, the steam passes from the
top side of piston a through port D, port e of valve E, down through the valve E
itself, and through port d³ to the lower side of piston b, and on the return stroke
from the lower side of piston a through port D', through the port e of valve E¹, up
through the valve E¹ itself, and through port d to the top side of piston b.
Figure 7 represents an engine that does not require to be reversed and the
reversing valves are accordingly omitted, the ports leading directly from the one
cylinder to the other, as shown. The steam and exhaust valves are the same as
before and the working of the engine is the same but in one direction only.
Having described the nature of the said Invention and the manner of performing
the same I declare that I do not claim as my Invention the controlling the admission
of steam to the low-pressure cylinder by means of the high-pressure piston but
what I do claim as my Invention to be protected by the herein-before in part recited
Letters Patent is
1st. A compound engine the high-pressure piston of which controls the admission
of steam to the low-pressure cylinder, in which the steam is exhausted from either
end of the high-pressure cylinder directly to the condenser or atmosphere on or
before the closing by the high-pressure piston of the port connecting the two cylinders
in order to avoid compression in the high-pressure cylinder substantially as herein
set forth.
2nd. The combination with a compound engine of the kind herein specified of
separate exhaust valves and ports for each end of both cylinders, substantially as
shown and described.

page_text: 3rd. The combination with a compound engine, of the kind herein shown and
described of a blank equilibrium valve for controlling the admission of steam to the
high-pressure cylinder, substantially as set forth.
4th. The employment in a compound engine, of the kind herein specified of blank
exhaust valves, substantially as shown and described.
5th. The combination with a compound engine of the kind herein specified of two
reversing valves as described fitted in corresponding cylinders or chambers
communicating with the two cylinders by ports, the said valves and ports being
arranged to control the passage for the steam from the high to the low pressure
cylinder as specified.
In witness whereof I the said Albion Vile have hereunto set my hand and
seal this Third day of April in the year of our Lord One thousand eight
hundred and seventy-eight.