IMPROVEMENTS IN COMPOUND ENGINES
Year: 1885

page_text: We, HAMILTON DANSEY and OTWAY ROBINSON of 14 Gracechurch Street, in the
city of London, Engineers do hereby declare the nature of the said invention for
"IMPROVEMENTS IN COMPOUND ENGINES" to be as follows:-
Hitherto in ordinary engines having single or double cylinders it has frequently
been the practice to start, stop and reverse the engine by turning the steam into
the ordinary exhaust port, but this method is not applicable to compound engines
as the exhaust from the low pressure cylinder when the engine is reversed having
to pass through the high pressure cylinder which is of smaller capacity compresses
the exhaust to such an extent that the engine will no longer act.
Our invention consists in conveying the the exhaust when the engine is reversed
direct from the low pressure cylinder to the condenser, or into the atmosphere if
no condenser is employed; and in providing a valve which governs both the steam
and the exhaust ports.
In carrying out our invention we provide an extra exhaust port on the low
pressure cylinder and we employ a valvo preferably an equilibrium valve so
constructed that it serves for the regulation of the steam, for cutting off the
exhaust and for reversing the engine.
By coupling our improved valve with an ordinary governor racing of the engine
would be effectually prevented as both the steam and the exhaust would thereby
be simultaneously cut off.

page_text: Improvements inFcompound uzinos.
We HAMILTON DANSEY and OTWAY ROBINSON of 14 Gracechurch Street, in the
city of London, 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:) I
Hitherto in ordinary engines having single or double cylinders it has frequently
been the practice to start, stop and reverse the engine by turning the steam into
the ordinary exhaust port, but this method is not applicable to compound engines
as the exhaust from the low-pressure cylinder when the engine is reversed having
to pass through the high pressure cylinder which is of smaller capacity compresses
the exhaust to such an extent that the engine will no longer act.
Our invention consists in conveying the exhaust when the engine is reversed
direct from the low pressure cylinder to the condenser, or into the atmosphere if
no condenser is employed; and in providing a valve which governs both the steam
and the exhaust ports.
In carrying out our invention we provide an extra exhaust port on the low
pressure cylinder and we employ a valve preferably an equilibrium valve so
constructed that it serves for the regulation of the steam, for cutting off the
exhaust and for reversing the engine.
By coupling our improved valve with an ordinary governor, racing of the engine
would be effectually prevented as both the steam and the exhaust would thereby
be simultaneously cut off.
In order to enable our invention to be fully understood we will proceed to
describe the same by reference to the accompanying drawing which represents a
section of a valve or apparatus constructed according to our invention applied to
the high and low pressure cylinders of a compound engine for the purpose of
enabling the said engine to be reversed.
;
a, represents the low pressure cylinder having the usual exhaust port b; and c,
is the high pressure cylinder to the valve chest of which steam is admitted
through the ordinary port or opening d; e, is the extra exhaust port formed in the
valve chest e¹ of the low pressure cylinder a, as shewn. Attached to the cylinders a
and c, is the cylindrical casing f, of the equilibrium valve g, in' which are formed
three ports h, i, and j, corresponding respectively with the ports b, e and d, on the
cylinders a and c.-An additional port k is 'formed in the valve casing f, the said
port connecting the interior of the casing f with the ports h and b. The valve g,
is formed cylindrical and has an annular groove l; it is open from one end to the
other so that when steam is admitted from the boiler through the ordinary steam
pipe m, into the casing f it is allowed access to both ends of the said casing;
n and o, are two ports placed on one side of the casing f, opposite to and
corresponding with the ports h and i, on the other side of the casing, the said
porta n, and o, opening into the usual exhaust pipe p which leads into the condenser
or into the atmosphere if no condenser is employed; q, is the rod serving to actuate
the valve g, to which it is attached.
The operation of the valve is as follows. When it is required to run the engine
in a forward direction, that is to say when it is required to supply the high pressure

page_text: cylinder c, with steam which shall pass from thence to the low pressure cylinder a,
the valve is moved into the position shewn in the drawing which allows the steam
from the boiler entering at m to pass in the direction of the arrows to the valve
chest d from which it is allowed to pass in the usual manner into the high pressure
cylinder c, by means of its slide valve which is not shewn in the 'drawing; the
steam is then exhausted by the said slide valve into the valve chest c¹, by means
of the ordinary exhaust pipo also not shewn in the drawing. The steam is then
admitted to the low pressure cylinder a by its valve (not shewn in the drawing)
the said valve again exhausting into the exhaust port b. The steam then passes
through the port h, round the annular groove l, through the port n, and passes away
through the exhaust pipe p, in the usual manner. When however it is required to
reverse the engine the valve g, is moved so as to uncover the port k, and close the
port j and at the same time the annular groove 7 will connect the two ports i and o.
The steam then will pass through the port k, into the exhaust port band is admitted
to the low pressure cylinder a, by means of its slide valve. It is then exhausted, as
will be well understood, into the valve chest e¹, and instead of passing into the exhaust
port of the high pressure cylinder c, to actuate the piston contained therein, the
steam will pass away through the port e round the annular groove l, through the
port o, and into the exhaust pipe p; it will thus be seen that the high pressure
cylinder c, is not brought into action at all when the engine is being reversed. The
valve g, can also be used to stop the engine, by moving it so that it covers either
the steam ports j and k, or the ports j and k, and exhaust ports h, and i; in the
latter case when the valve is coupled to and actuated by a suitable governor, racing
of the engine will be effectually prevented. It will be obvious that the valve g, can
be applied in various ways to suit the various requirements of differently constructed
compound engines, without departing from the spirit of our invention.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
1. Providing the low pressure cylinders of compound engines with an extra
exhaust port substantially as and for the purpose herein before described and
represented in the accompanying drawing.
2. In a compound engine the use of a valve constructed so as to serve for the
regulation of the steam, for cutting off the exhaust, and for reversing the engine
substantially as hereinbefore described and represented in the accompanying
drawing.