IMPROVEMENTS IN COMPOUND STEAM ENGINES
Year: 1885

page_text: I, THOMAS WILLIAM WORSDELL, of Hermon Hill, Wanstead, in the County of
Essex, Engineer, do hereby declare the nature of said invention for "IMPROVEMENTS
IN COMPOUND STEAM ENGINES to be as follows
وو
This invention has reference to compound steam engines of the locomotive type
but may be applied in engines for other uses.
A description of it as applied to an inside cylinder locomotive engine will enable
the nature of the invention to be clearly understood.
Two cylinders are employed, one for high pressure and the other for low pressure,
so arranged that they can be applied to the same cranks, rods, valve gears,
reversing motion et cetera, as in an ordinary high pressure engine; the pistons
operating on one crank axle in the usual way.
One of the cylinders, the high pressure or smaller one, takes steam direct from
the boiler. When this steam is exhausted it passes through a superheater pipe or
chamber to the low pressure cylinder. After performing its function therein the
steam from the low pressure or larger cylinder is exhausted direct up the chimney,
or where required can be passed through a feed water heater, or wholly or partially
condensed by being led into the water tank of the engine or tender.
To render the engine efficient in starting if the crank on the high pressure side
should be on a dead centre, an auxiliary or starting valve is provided, by which
steam can be conveyed direct from the boiler to the low pressure or larger cylinder,
and in order to prevent such steam filling the exhaust steam pipe or chamber of
the high pressure cylinder and consequently also the high pressure or smaller
cylinder itself through the exhaust ports there is provided a valve that I will call
the intercepting valve. It is applied in the exhaust pipe or passage that connects
the two cylinders and is arranged between the starting valve and the high pressure
exhaust orifice, (conveniently it may be just above the starting valve).
When closed this intercepting valve will prevent the steam getting back to the
high pressure piston. This valve may be of any suitable kind (such for examples
as disc, butterfly, or slide) but I consider it advantageous to use a flap or foot valve,
closed by hand gear from the foot plate, and thrown back so as to have a clear
passage immediately the exhaust takes place from the high pressure cylinder.
A flap valve as described is preferred as it can be closed at will and will always
be thrown open by the steam itself when exhausting commences from the high

page_text: pressure cylinder thus leaving the passage unobstructed. The starting valve may
be arranged to be opened by hand against a spring so as when liberated to be closed
in an automatic manner.
The low pressure cylinder is or may be fitted with a relief valve at each end to
prevent the cylinder being charged at too high a pressure when steam is admitted
direct from the boiler through the starting valve.
Such valves will also become self-acting wasto cocks for the expulsion of water.
My invention as described may be carried out under various arrangements
and is applicable to ordinary locomotive engines, whether of the inside or outside
cylinder type.
As will be evident an intercepting valve such as above described is applicable
to engines of various types wherein exhaust steam passes from a high pressure
cylinder to do duty in a low pressure cylinder, and where a starting valve is
applied.

page_text: 1, THOMAS WILLIAM WORSDELL, of Hermon Hill, Wanstead, in the County of
Essex, Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS
IN COMPOUND STEAM ENGINES 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 compound steam engines of the locomotive type
but may be applied in engines for other uses.
A description of it as applied to an inside cylinder locomotive engine will enable
the nature of the invention to he clearly understood.
Two cylinders are employed one for high pressure and the other for low pressure
so arranged that they can be applied to the same cranks, rods, valve gears, reversing
motion et-cetera as in an ordinary high pressure engine, the pistons operating on
one crank axle in the usual way.
One of the cylinders, the high pressure or smaller one takes steam direct from
the boiler. When this steam is exhausted it passes through a superheater pipe or
chamber to the low pressure cylinder. After performing its function therein the
steam from the low pressure or larger cylinder is exhausted direct up the chimney
or when required can be passed through a feed water heater, or wholly or partially
condensed by being led into the water tank of the engine or tender.
To render the engine efficient in starting, if the crank on the high pressure side
should be on a dead centre an auxiliary or starting valve is provided, by which
steam can be conveyed direct from the boiler to the low pressure or larger cylinder,
and in order to prevent such steam filling the exhaust steam pipe or chamber of the
high pressure cylinder and consequently also the high pressure or smaller cylinder
itself through the exhaust ports there is provided a valve that I will call the
intercepting valve. It is applied in the exhaust pipe or passage that connects the
two cylinders and is arranged between the starting valve and the high pressure
exhaust orifice; conveniently it may be just above the starting valve. When
closed this intercepting valve will prevent the steam getting back to the high
pressure piston. This valve may be of any suitable kind (such for example as
dise or butterfly) but I prefer to use a flap or foot valve. It is closed by hand gear
from the foot plate and thrown back so as to leave a clear passage immediately the
exhaust takes place from the high pressure cylinder. A flap valve as described is
preferred as it can be closed at will, and will always be thrown open by the steam
itself when exhausting commences from the high pressure cylinder, thus leaving the
passage unobstructed. The starting valve may be arranged to be opened by hand
against a spring so as when liberated, to be closed in an automatic manner.
The low pressure cylinder is or may be fitted with a relief valve at each end to
prevent the cylinder being charged at too high a pressure when steam is admitted
direct from the boiler through the starting valve. Such valves will also become
self acting waste cocks for the expulsion of water.
My invention as described is not only applicable to ordinary locomotive engines
whether of the inside or outside cylinder type, but, as will be evident, an inter-
cepting valve such as above described is applicable to engines of various types
wherein exhaust steam passes from a high pressure cylinder to do duty in a low
pressure cylinder and where a starting valve is applied.
In the accompanying drawing Fig 1 is a vertical section through the smoke box
of a locomotive engine, according to this invention. Fig 2 is a section in a plane at
right angles to Fig 1-Figs 3 and 4 are sectional detail views shewing the inter-
cepting valve.

page_text: The high pressure cylinder A receives its steam from the boiler in the usual
manner, the distribution of the motive fluid being effected by any suitable arrange-
iment of valve and valve gear. After the steam has performed its office in the
cylinder it is exhausted into the pipe B which traverses the smoke box and acts as
a superheater. This pipe delivers the steam to the valve chest of the low pressure
cylinder C from which it passes into the cylinder and from thence into the exhaust
or blast pipe D. In the pipe B which forins the communication between the two
cylinders there is a branch E connected to the boiler, and serving for the admission
of full pressure steam to the large cylinder (when required. This branch E is
commanded by an auxiliary starting valve F, which can be opened and closed from
the foot plate.
There is also arranged in the pipe B between the inlet of the branch E, and the
high pressure cylinder an intercepting valve G, which is shewn in section in the
detail views Figs 3 and 4. This is shewn in the drawings as a flap or foot valve
mounted upon a spindle, and operated by a lever which can be manipulated from
the foot plate either simultaneously with the auxiliary starting valve or
independently of it. When the intercepting valve is open it allows a clear passage
for the steam, the tendency of the pressure during the normal working being to
hold the valve open.
When it is closed it prevents the high pressure steam which
is admitted to the large cylinder through the auxiliary valve finding its way to the
reverse side of the piston in the high pressure cylinder as already fully explained.
A relief valvo H is fitted to each end of the large cylinder to prevent the steam
pressure exceeding a determined amount, and to allow escape of any water that
may be present therein.
Both cylinders work on to one crank shaft and have their valves operated in the
usual way.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In a compound engine the adaptation and use to render the engine efficient in
starting without opening the high pressure cylinder to the atmosphere when the
crank on the high pressure side is on a bad starting point such as a dead centre, of
two independent valves, namely, the auxiliary or starting valve F and the inter-
cepting valve G the auxiliary or starting valve being to admit steam directly from
the boiler to the low pressure or larger cylinder and the intercepting valve being
applied in the exhaust pipe or passage that connects the two cylinders and being so
arranged between the starting valve and the high pressure exhaust orifice as to
close the exhaust passage from the high pressure cylinder, and to also prevent steam
admitted directly from the boiler to the low pressure or larger cylinder as above
mentioned from filling the exhaust steam pipe or chamber of the high pressure or
smaller cylinder and consequently also the high pressure or smaller cylinder itself,
through the exhaust, substantially as hereinabove described, with reference to and
illustrated in the drawings.
2. In a locomotive engine (whether having inside or outside cylinders) the
hereinabove described arrangement of parts comprising the high and low pressure
cylinders A and C, superheater pipe B, auxiliary starting valve F, intercepting
valve G and relief valve H operating as specified for the purposes set forth.
T
1011
A
1 100F
VA
April
T. W. WORSDELL.
W. Lloyd Wise,
46, Lincoln's Inn Fields,
Applicant's Agent.