Improved Triple Expansion Steam Engine
Year: 1892

page_text: Date of Application, 12th Oct., 1892-Accepted, 10th Dec., 1892
COMPLETE SPECIFICATION.
Improved Triple Expansion Steam Engine,
I, HENRY DAVEY, of 3, Princes Street, Westminster, in the County of Middlesex,
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 relates to an improved construction of triple expansion steam
engine.
Figs. No. 1 and No. 2 are elevation views. I arrange two sets of steam
cylinders, a, m, and b, L, of different diameters, into which are fitted trunk pistons e
and e.
The upper ends of the said trunk pistons forming the pistons and d of
the high pressure cylinders, and the lower ends 9 and 1, the pistons of the low
pressure cylinders.
0,
o' and
P, pare piston valves placed on either side of the cylinders.
E, E' are the exhaust ports which are connected together and run into the same
exhaust pipe.
R, R are the crossheads; v, v are the guides; z, the connecting rods;
t, t, the cranks, which are placed at angles of 180 degrees, that is-opposite each
other; x, x are the eccentric rods, and u, u¹, the eccentrics; w, w¹ are covers or
doors to back and front of the engine to form a closed in crank chamber.
Fig. No. 3 is a plan view of the engine shewing the distribution of the steam
ports to valve chambers and cylinders.
The piston valves o, o¹, and p, p², for effecting the distribution of the steam are
actuated from eccentrics or their known equivalents in rotative engines, and by
means of subsidiary cylinders or other well known means in non-rotative engines.
By means of the piston valves and passages, the distribution of steam is thus
effected :-
Referring to diagrams A and B which I have made to indicate clearly the
distribution of steam and working of the engine :-
Steam enters at S, S¹, and flows into the high pressure cylinder a, and, at the
same time, the steam which had entered the cylinder b during the previous down
stroke of the high pressure piston d, is passed from cylinder to cylinder i in
diagram A, whilst the steam which entered j from the previous up stroke off is
expanded from the annular space into the low pressure cylinder L, below the
piston h. At the same time, the steam which entered the low pressure cylinder m
during the previous up stroke of h, from the annular space j, is exhausting into
the exhaust pipe E.
Diagram C represents a modification in which the pistons-instead of being
coupled to a crank shaft with cranks-as in Figs. 1 and 2, and diagrams A and B-
are, together with the cylinders, placed end to end, and the said pistons are coupled
together by a piston rod H. The piston valves o, o', and p, p', are also coupled
together as shewn in diagram C.
The distribution of steam is precisely the same as in the first arrangement, shewn
in Figs. 1, 2, and 3, and in diagrams A and B.
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:
1st. The combination of the cylinders a, b, L, m, the pistons f, d, h, g, and the
valves o, o, p, p', in the manner substantially as described and illustrated in

page_text: 2nd. The combination of the cylinders a, b, L,.m, the pistons f, d, h, g, and the
valves o, o, p, p, in the manner substantially as described and illustrated, in
diagram C.
.
1
1000
HENRY DAVEY.