Improvements in Steam Engines.
Year: 1890

page_text: Date of Application, 28th Mar., 1890
Complete Specification Left, 17th Dec., 1890-Accepted, 17th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Steam Engines.
We, WILLIAM HENRY ALLEN, RICHARD WRIGHT, and RICHARD WILLIAM ALLEN,
all of York Street Works, Lambeth, in the County of Surrey, do hereby declare the
nature of this invention to be as follows:-
Our invention relates to steam engines in which steam at a sufficiently high pressure
is admitted to a cylinder, after actuating the piston in which it passes to a larger
cylinder in which it continues to do useful work during its expansion and in some
cases is subsequently passed to one or more still larger cylinders. Our present invention
is applicable more especially to that form of such engines in which the smaller and
larger double-acting cylinders are arranged side by side their pistons operating
by connecting rods directly upon cranks arranged opposite to each other upon
a shaft.
In the Provisional Specification accompanying our application for Letters Patent
dated December 9th, A.D. 1889, and numbered 19714, we described an engine of the
kind referred to in which steam is admitted to the smaller or high pressure cylinder
through a valve which is not used as an exhaust valve to the larger cylinder also, but
simply as an admission and cut off valve.
The steam from this cylinder is exhausted into a chamber in which works a
cylindrical valve between the two cylinders, and serving both as the eduction valve of
the small cylinder and the admission or distributing valve of the larger cylinder and
the steam was finally exhausted, from the larger cylinder by means of a separate
exhaust valve.
By our present invention we avoid the necessity for the separate inlet steam and
cut off valve described in our said former Provisional Specification, and we employ
two valves only instead of three. For this purpose, in the case of compound engines
having a small and a large cylinder, we cast the two cylinders preferably in one
piece, making at the same time a steam jacket round both the high pressure
cylinder, the central valve between the two cylinders, and part, of the low pressure
cylinders.
The high pressure steam is admitted into this jacket from a suitable pipe, and from
it the steam enters the steam chest between the two cylinders which contains the
valve. This valve is preferably cylindrical, consisting of two cylindrical pistons
connected together by a rod one end of which passes through a stuffing box and is
actuated by an excentric or other equivalent means in the usual way. This valve fits
and works in a case provided with ports or openings through which the steam is
admitted to, cut off, and exhausted from, the two cylinders at the required times.
The steam is admitted from the jacket into the space between the two pistons, and
from this space through ports to the upper and lower ends of the small cylinder
alternately as the valve reciprocates up and down.
The inner edges of the two pistons which form the valve serve to cut off at the
right times the steam so admitted to the smaller cylinder, and their outer edges
uncover the same ports and allow the steam from this smaller cylinder to pass into
the ends of the valve casing and thence into ports leading to the ends of the larger
cylinder.
The central valve, therefore, forms an admission valve to the high pressure cylinder,
a cut off valve for the high pressure cylinder, an admission valve for the low pressure
cylinder, and a cut off valve for the low pressure cylinder.
The low pressure or larger cylinder has a separate exhaust valve of any ordinary
form of construction, preferably cylindrical. We prefer to make three ports or
openings through and round the circumference of the casing which contains the

page_text: valve, for the admission of steam to the valve, in order that the latter may be balanced
and kept in equilibrium.
By our present invention the construction of the engine is considerably simplified
and cheapened, and it is very effective in action, the flow of steam being kept in
one direction continuously in expansion, without coming in contact with the lower
temperature steam, or the atmosphere, as in ordinary engines. where the high pressure
steain has to pass into the ports, which have been reduced in temperature by the
exhaust, steam, and then passed through an eduction pipe outside the cylinder and
exposed to the atmosphere.
EDWARDS & Co.,
35, Southampton Buildings. Chancery Lane, London,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Steam Engines.
We, WILLIAM HENRY ALLEN, RICHARD WRIGHT, and RICHARD WILLIAM ALLEN,
all of York Street Works, Lambeth, in the County of Surrey, Engineers, 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, and
accompanying drawing, that is to say :-
Our invention relates to steam engines in which steam at a sufficiently high
pressure is admitted to a cylinder, after actuating the piston in which, it passes to a
larger cylinder in which it continues to do useful work during its expansion and in
some cases is subsequently passed to one or more still larger cylinders. Our present
invention is applicable more especially to that form of such engines in which the
smaller and larger double-acting cylinders are arranged side by side their pistons
operating by connecting rods directly upon cranks arranged opposite to each other
upon a shaft.
In the Specification of our Letters Patent dated December 7th, A.D. 1889, and
numbered 19714, we described and shewed an engine of the kind referred to in
which steam is admitted to the smaller or high pressure cylinder through a valve
which is not used as an exhaust valve to the larger cylinder also, but simply as an
admission and cut off valve.
The steam from this cylinder is exhausted into a chamber in which works a
cylindrical valve between the two cylinders, and serving both as the eduction valve
of the small cylinder and the admission or distributing valve of the larger cylinder
and the steam was finally exhausted from the larger cylinder by means of a separate
exhaust valve.
By our present invention we avoid the necessity for the separate inlet steam and
cut off valve described in our said former Specification, and we employ two valves
only instead of three. For this purpose, in the case of compound engines having two
cylinders, a small and a large one, we cast the two cylinders preferably in one piece,
making at the same time a steam jacket round both the high pressure cylinder, the
central valve between the two cylinders, and part of the low pressure cylinders.
The high pressure steam is admitted into this jacket from a suitable pipe, and from
it the steam enters the steam chest between the two cylinders which contains the
valve. This valve is preferably cylindrical, consisting of two cylindrical pistons con-
nected together by a rod one end of which passes through a stuffing box and is
actuated by an excentric or other equivalent means in the usual way. This valve fits
and works in a case provided with ports or openings through which the steam is
admitted to, cut off, and exhausted from, the two cylinders at the required times.
The steam is admitted from the jacket into the space between the two pistons and
from this space through ports to the upper and lower ends of the small cylinder
alternately as the valve reciprocates up and down.
The inner edges of the two pistons which form the valve serve to cut off at the

page_text: right time the steam so admitted to the smaller cylinder, and their outer edges
uncover the same ports and allow the steam from this smaller cylinder to pass into
the end of the valve casing and thence direct into ports leading to the ends of the
larger cylinder.
The central valve, therefore, forms an admission valve to the high pressure cylinder,
a cut off valve for the high pressure cylinder, an admission valve for the low pressure
cylinder, and a cut off valve if required for the low pressure cylinder.
The low pressure or larger cylinder has a separate exhaust valve of any ordinary
form of construction preferably cylindrical. We prefer to make three ports or
openings through and round the circumference of the casing which contains the
valve for the admission of steam to the valve, in order that the latter may be balanced
and kept in equilibrium.
The accompanying drawing is in illustration of our invention, Figure 1 being a
longitudinal vertical section. and Figure 2 a horizontal section, through the cylinders.
a is the high pressure cylinder and the low pressure cylinder, shewn cast together
in one piece and provided with pistons in the usual way, and c is a steam jacket sur-
rounding the high pressure cylinder a, the central valve d, d, and part of the low
pressure cylinder . High pressure steam is admitted into the jacket c through the
steam pipe at e, and from the jacket the steam enters the steam chest f, through a
port g, between the two pistons d, d', which form the central valve. The piston
valves d, d', are connected together by a rod ha continuation of which passes through
a stuffing box i and is actuated by excentrics or other equivalent means in the usual
way. The valves d, d', fit and work in a case k provided with ports I, I, I, I, by which
the steam between the valves d, d', is admitted as desired to the two ends of the
cylinder a alternately, is cut off at the determined times, and is allowed to pass
directly to the corresponding ends of the large cylinder b. The inner edges of the
piston valves d, d', serve to cut off the steam admitted to the high pressure cylinder a,
and their outer edges uncover the same ports and allow the steam to pass from the
ends of the cylinder a alternately into the ends of the valve casing or steam chest f,
and thence into the ports m, m³, leading direct into the ends of the large cylinder b.
The large or low pressure cylinder bis provided with a separate exhaust valve also
consisting preferably of two piston valves n, n', working in a casing o, the ends of
which communicate with the exhaust pipe at p. The spindle of the exhaust valve
passes through a stuffing box s, and is actuated in the usual way by an excentric or
equivalent device. The exposed parts of the engine at t, t, t, are preferably packed or
covered with asbestos or other suitable non-conducting material. The several parts
are easily and readily accessible.
By our present invention the construction of the engine is considerably simplified
and cheapened, and it is very effective in action, the flow of steam being kept in one
direction continuously in expansion, without coming in contact with the lower
temperature steam, or the atmosphere, as in ordinary engines, where the high pressure
steam has to pass into the ports, which have been reduced in temperature by the
exhaust steam, and then passed through an eduction pipe outside the cylinder and
exposed to the atmosphere.
The clearance and surface are reduced to a minimum, all receiver space and surface
being dispensed with, and the exhaust from the large or low pressure cylinder being
regulated by a separate valve through short ports, does not come in contact with
the parts heated by the initial high pressure steam and the condensation is thus
lessened.
We do not confine ourselves to the particular arrangement, form, and dimensions of
the several parts, which may be varied more or less according to the circumstances in
which the engines are to be used, but
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
1. In a compound engine having a high pressure cylinder and a low pressure

page_text: cylinder, the valve d, d¹, arranged between the cylinders, and serving as an admission,
cut off, and exhaust valve to the high pressure cylinder and an admission valve to the
low pressure cylinder, in combination with the exhaust valve n, n¹, from the low
pressure cylinder, substantially as described and shewn.
2. In a compound engine having a high pressure cylinder and a low pressure
cylinder, the combination with the two cylinders of the steam jacket admission
pipe at e, port g, valve casing k, valve d, d¹, ports 1, 1, 1, 1, and m, m³, and exhaust
valve n, n, all arranged and operating substantially as described and shewn.
T17L
1000
EDWARDS & Co.,
35, Southampton Buildings, Chancery Lane, London,
Agents for the Applicants.
EDWARDS & Co.,
35, Southampton Buildings, Chancery Lane, London,
Agents for the Applicants.