Improvements in Steam Engines.
Year: 1896

page_text: Improvements in Steam Engines.
I, MATTHEW PAUL, of Levenford Works, Dumbarton, in the County of Dum-
barton, North Britain, Engineer, do hereby declare the nature of this Invention
to be as follows, that is to say:-
My said Invention relates to steam engines working with two or more stages
of expansion, and comprises an improved construction and combination of parts
suitable for high speeds, and otherwise advantageous.
In an engine made with my improvements and arranged to act on a single
crank, with two stages of expansion, a large low-pressure cylinder has fixed to
its upper or outer end a small high-pressure cylinder, and the high-pressure piston
connected by a rod to the low-pressure piston has between it and the latter a
casing or closed trunk of very nearly the diameter of the high-pressure cylinder
or the pistons and trunk may be combined in one casting. The pistons are single
acting the smaller one receiving high-pressure steam on its upper or outer
side and the larger one receiving steam on the upper
the upper annular part
of it formed by the excess of its diameter over that of the high-pressure piston.
The admission port to the low-pressure cylinder is, preferably, in the same casting
as the high-pressure cylinder, and in the conical or other-shaped flange with
which the high-pressure cylinder is joined to the low-pressure cylinder. The
steam distribution is effected by means of two valve pistons fixed on one piece;
and a space acting as an intermediate receiver is formed in the chamber in which
the valve works, the steam exhausting from the high-pressure cylinder into the
receiver and passing thence into the low-pressure cylinder.
The pistons may be connected to the crank in any known suitable way; and
the crank shaft and the lower or nearer part of the engine may be enclosed in a
casing or not.
For more than two stages of expansion three or more cylinders may be com-
bined tandem. Two or more sets of the cylinders may be combined to act on
two or more cranks; and when two sets are combined a single valve piece with
suitably placed valve pistons on it may be arranged between the two sets of
cylinders; or each set of cylinders may have a separate valve piece.
By suitably proportioning the intermediate receiver space a back pressure on
the high-pressure piston may be obtained such as to prevent back lash of the parts
connecting the piston to the crank shaft.
Dated this Fourth day of December 1896.
EDMUND HUNT,
Applicant's Agent.

page_text: I, MATTHEW PAUL, of Levenford Works, Dumbarton, in the County of Dum-
barton, North Britain, 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, that is to say:-
My said Invention relates to steam engines working with two or more stages
of expansion, and comprises an improved construction and combination of parts
suitable for high speeds, and otherwise advantageous.
Part of an engine as made according to my Invention is shown on an accom-
panying sheet by an explanatory drawing as in vertical section. In this drawing
the same reference letters are used to mark the same or like parts wherever they
are repeated.
In an engine made with my improvements (such as is shown in the drawing)
and arranged to act on a single crank, with two stages of expansion, a large low-
pressure cylinder, A, has fixed to its upper or outer end, a small high-pressure
cylinder, B, and the high-pressure piston, C, and the low-pressure piston, D,
together with a casing or trunk, E, between them having a diameter nearly equal
to that of the high-pressure cylinder, are formed in one casting, the part between
the low-pressure piston and the trunk being conical. The pistons, C, and D,
however might be connected by a rod with a casing or closed trunk between them.
The pistons, C, and D, are single acting the smaller one receiving high-pressure
steam on its upper or outer side and the larger one receiving steam on the upper
conical, that is the annular part of it formed by the excess of its diameter over
that of the high-pressure piston. The admission port, G, to the low-pressure
cylinder, cylinder, A, is preferably in the same casting as the high-pressure
cylinder, B, and in the conical or other shaped flange, H, with which the high-
pressure cylinder is joined to the low-pressure cylinder. The steam distribution
is effected by means of two valve pistons, J, and K, fixed or formed on one piece, L;
and a space, M, acting as an intermediate receiver is formed in the chamber in
which the valve works, the steam exhausting from the high-pressure cylinder, B.
into the receiver, and passing thence into the low-pressure cylinder.
The pistons, C, and D, may be connected to the crank in any known suitable
way; as for example the top end of the connecting rod, P, may (as shown in the
drawing) be jointed to a piece, Q, held centrally at the lowermost part of the
trunk, E, by a tubular rod, R, passing upwards and held by a nut, S, on the upper
side of the high-pressure piston. The tubular rod, R, extends through a stuffing
box, T, in the high-pressure cylinder cover, U, and acts as a tail rod, and it has
within it a long tube, V, by means of which the connecting rod pin, W, is
lubricated. The crank shaft and the lower or nearer part of the engine may be
enclosed in a casing or not.
For more than two stages of expansion three or more cylinders may be com-
bined tandem. Two or more sets of the cylinders may be combined to act on
two or more cranks; and when two sets are combined a single valve piece with
suitably placed valve pistons on it may be arranged between the two sets of
cylinders; or each set of cylinders may have a separate valve piece.
By suitably proportioning the intermediate receiver space, M, a back pressure
on the high-pressure piston, C, may be obtained such as to prevent back lash of
the parts connecting the piston to the crank shaft.

page_text: 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:-
The improved single-acting steam engine made with two or more cylinders
tandem and having pistons with a trunk or trunks between them, made in one
or more castings, the said parts and the distribution valve details being sub-
stantially such as are herein before described and shown in the accompanying
drawing.
of Aument 1907