Improvements in or connected with Compound Steam Engines.
Year: 1893

page_text: Date of Application, 19th Dec., 1893
Complete Specification Left, 19th Sept., 1894-Accepted, 20th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements in or connected with Compound Steam Engines.
I JAMES SHANKS Junior B. Sc. of Dens Iron Works Arbroath in the County
of Forfar Engineer do hereby declare the nature of this invention to be as
follows:-
My invention has for its object to provide a simple and efficient compound steam
engine and it relates more especially to engines having two cylinders connected to
opposite cranks on the crank shaft the one cylinder being a high pressure cylinder
and the other a low pressure cylinder receiving steam from the high pressure
cylinder, the valvular arrangements for the two cylinders being situated between
the cylinders and having their rods connected to one cross-head guided in guides
which may be secured to the valve chest the said cross-head being operated by one
eccentric from the shaft so that the oue eccentric actuates both valves. The valves
for distributing the steam to and from the high pressure cylinder and to and from
the low pressure cylinder work in one valve chest provided with passages for the
steam the said valves and passages being so arranged and proportioned that the one
valve cuts off by means of its outside edges and the other valve by means of its.
inside edges.
The engine is preferably arranged as a vertical engine with the cylinders above
the crank shaft.
Dated this 10th day of December 1802
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPecification.
Improvements in or connected with Compound Steam Engines.
I, JAMES SHANKS Junior B. Sc. of Dens Iron Works Arbroath in the County of
Forfar 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 :-
My invention has for its object to provide a simple, and efficient, compound steam
engine, and it relates more especially to engines such, for instance, as that shewn in
side elevations, at right angles to each other, in the accompanying drawings,
Figures 1 and 2, the said engine having two cylinders A and B, connected to
opposite cranks a, b on the crank shaft e the cylinder A being a high pressure
cylinder and the other (B) a low pressure cylinder, receiving steam from the high
pressure cylinder A, the valvular arrangements for distributing steam to, and from,
the high pressure cylinder, and to, and from, the low pressure cylinder, being
situated between the cylinders A and B.
The valves F, G, have their rods f, g, connected to one crosshead D guided in
guides d, which may be secured to the valve chest C, as shewn, the said cross
head D being operated by one eccentric E, from the crank shaft e, so that the one
eccentric E, actuates both valves F. and G, which valves work in one valve chest C,
provided with passages for the steam, the said valves, and passages, being so
arranged, and proportioned, that the one valve cuts off by means of its outside
edges, and the other valve cuts off by means of its inside edges.

page_text: Figure 3 shews this valvular arrangement in vertical section, the valves shewn
being piston valves. The valve F controls the ports for alternately admitting live
steam from the boiler to the cylinder A, and for exhausting the steam from the
cylinder A to the cylinder B, the ports through which steam is alternately admitted
to the cylinder B, and exhausted therefrom, to the condenser, or to the outer air,
being controlled by the valve G.
It will be seen that in the arrangement shewn the valve F, cuts off steam by
means of its outside edges f³, and the valve G, cuts off steam by means of its inside
edges g³.
The positions of the valves at the ends of their down stroke are shewn in full
lines their positions at the ends of their upstroke being shewn by the dotted lines.
The dotted line at - indicates the positions of the two cranks, and the arrow
indicates the direction in which the engine is presumed to be running.
The engine is preferably arranged as a vertical engine with the cylinders above
the crank shaft, as in the example shewn in the drawing, but this is not essential.
Having now particularly described the nature of my invention, and the manner
in which it is to be performed, I declare that what I claim is :-
1. The combination of parts constituting the valvular arrangement for compound
steam engines, substantially as hereinbefore described and illustrated by Figure 3
of the accompanying drawings.
2. In, or for, compound steam engines two separate piston valves, having both
their rods connected to one cross-head driven by one eccentric and operating
substantially as hereinbefore described and illustrated by the accompanying
drawings.
3. The combination of high and low pressure steam cylinders, having their piston
rods connected to two diametrically opposite cranks, and two piston valves having
their rods connected to one crosshead, and this crosshead connected to one eccentric,
so that the one eccentric operates both valves, substantially in the manner herein-
before described.
Dated this 19th day of September 1894.