Quadruple Expansion Steam Engines.
Year: 1889

page_text: Date of Application, 29th Oct., 1889
Complete Specification Left, 26th Aug., 1890-Accepted, 11th Oct., 1890
PROVISIONAL SPECIFICATION.
Quadruple Expansion Steam Engines.
WILLIAM WALLACE GIRDWOOD of No. 9 Lea Cottages East India Dock Road
Poplar, E., in the County of Middlesex, Engineer, do hereby declare the nature of
this invention to be as follows:-
This invention has reference to & comprises improvements in the combination &
construction, or arrangement of the cylinders in quadruple expansive engines, which
may be of the receiver or continuous expansion type for marine & other purposes
with the object of a reduced consumption of coal, making them more compact also
for occupying very much less space than has hitherto been attainable & for taking
away all transverse strains from off the ship & engine framing also reducing the strains
on the shafting which may be much smaller for the unit of work done. In these
arrangements of my improvements for quadruple expansive engines the main or
essential novelty consists in having the cylinders placed at an angle of 90° with each
other, working on two cranks.
Dated this 28th day of October 1889.
COMPLETE SPECIFICATION.
Quadruple Expansion Steam Engines.
I WILLIAM WALLACE GIRDWOOD of 9 Lea Cottage, East India Dock Road,
Poplar, in the County of Middlesex Engineer, do hereby declare the nature of my
said invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
This invention relates to the combination and disposition or arrangement of the
cylinders in quadruple expansion steam engines which may be of the receiver or con-
tinuous expansion type for marine and other purposes, and has for its objects to effect
a more perfect balance of the moving parts and turning forces than has been possible
with engines as heretofore arranged, and thereby obviate prejudicial vibrations and
render neutral disturbing transverse strains on the ship and on the engine framework;
to apply the driving effort to the cranks so as to produce a more uniform turning
couple, thus reducing the maximum strains and consequently reducing the diameter
of the crank shaft and that of the screw shaft required, and thereby increasing the
efficiency of the engine and diminishing the consumption of fuel; and also to reduce
the space occupied by an engine of a given power.
In carrying out this invention the four cylinders are arranged in pairs, at right
angles to one another, one cylinder of each pair being connected to the same crank
journal. The two cranks to which the four cylinders are connected are placed with
their journals opposite one another and the steam is so admitted and released by
suitable valves and gear that the energy exerted upon each piston is equal or nearly
so, thereby producing a practically uniform turning couple, and so reducing the
maximum strains on the cranks, crank shaft, journals, framing and ship, and con-
sequently the sizes and weights of the crank shaft and other parts. The reciprocating
parts connecting each cylinder to the crank shaft are of the same weight, and as the
cranks are arranged opposite to one another, they consequently mutually balance one
another and do away with all vibrations.
In the accompanying two sheets of diagrammatic or skeleton drawings,
Fig. 1 is a side elevation and
Fig. 2 a front elevation of a quadruple expansion steam engine arranged according
to this invention.

page_text: The four cylinders a b c d are arranged in pairs at right angles to one another, one
piston rode of each pair being connected to the same crank journal while the
remaining two piston rods are similarly connected to the other crank journal g, the
two cranks fg being placed opposite one another as clearly shown.
Figs. 3 and 4 show a side and end elevation respectively of a modified arrange-
ment in which the vertical cylinders are inverted the connecting rods being attached
to the cross heads hi on the piston rods 1.
It will be seen that by the arrangements shown the space occupied by engines of a
given power is greatly reduced.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In quadruple expansion steam engines, arranging the cylinders in pairs at right
angles to one another, one cylinder of each pair being connected to the same journal
of the crank shaft, substantially as described.
2. In quadruple expansion steam engines in which the cylinders are arranged in
pairs at right angles to one another, the arrangement of the driving cranks
diametrically opposite one another substantially as described and shown and for the
purpose specified.
3. The arrangement and construction of quadruple expansion steam engines sub-
stantially as described with reference to the drawings.
Dated this 23rd day of August 1890.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, Engineers and Patent Agents