IMPROVEMENTS IN AND RELATING TO THE COUPLING AND DRIVING OF THE SHAFTS OF TWIN SCREW VESSELS
Year: 1884

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COMPLETE SPECIFICATION.
I WILLIAM ROBERT LAKE of the firm of Haseltine Lake & Co Patent Agents
Southampton Buildings in the County of Middlesex do hereby declare the nature
of my Invention for "IMPROVEMENTS IN AND RELATING TO THE COUPLING AND
DRIVING OF THE SHAFTS OF TWIN SCREW VESSELS" and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
1
The object of the present Invention is the coupling and driving of the shafts of
twin screw vessels with a single set of engines without wheel gearing or additional
rods or levers for coupling.
For driving and coupling the shafts of twin-screw-vessels according to tho
present Invention, three cylinders at least are necessary. The said cylinders are
placed horizontally athwartship, and one behind the other, although not necessarily
in one line.
In the accompanying Drawings
Figures 1 and 2 are side elevations of the first and second cylinders of a three-
cylinder engine constructed' according to this Invention, and
Figure 3 is a plan of the same.
"
* 4* 1.03
The cylinder B, which I will call the leading high-pressure cylinder, is provided
with two connecting rods b b. The connecting rod b which is double and is
connected with two cranks drives the starboard crank shaft A; the other rod b',
which is single, actuates the port crank-sliaft A¹.`
"The cylinders C and D are each provided with a single or double connecting
rod c, d, respectively, the rod c of the cylinder C being connected with the port
crank shaft A', while the rod d of the cylinder D is connected with the starboard
crank shaft A. The cranks of each shaft stand at right angles to each other.
By this arrangement there is no obstacle to the free motion of the shafts A A¹ in
either direction for driving ahead of astern seeing that the pistons of the
cylinders C D are independent of each other and can follow the motion imparted
to the crankshafts A A¹ by the leading cylinder-B.."

page_text: By means of the two connecting rods, b b¹, of the leading cylinder B the crank
shafts A. A', working in conjunction with the cylinders CD, are coupled effectually
and in a free and most simple manner. The forward motion of the vessel is
indicated by the arrows and can be reversed.
So long as the engine is under pressure there is no liability of one of the shafts
taking a wrong direction, but on turning the engine by hand care is necessary to
prevent this from taking place. For this purpose the wheels E E¹ and hand
gearing are used when the cranks actuated by the leading cylinder B are passing
the dead centres.
In small engines the slide valves of the cylinders C D, having each a connecting
rod at one end only, can be worked by one pair of excentrics.
In Figure 2, which is a side elevation of the second or middle cylinder C which
is the low pressure cylinder, the position of the engines in a large man-of-war is
shown, F being the water line and G the armour plated deck, which, as will be
observed, can be laid lower if required, especially at the sides. The dotted lines xx
show the position of the cranks actuated by the leading cylinder B, and the dotted
lines y, y, the position of the crank of the third engine or cylinder D.
As the cranks of each shaft are at right angles to each other the position of the
engines as represented on the Drawings is that in which the greatest difference
takes place in the relative positions of the pistons of the two low-pressure
cylinders C and D, as can be observed by the position of the central lines of the
side levers, (the lever of the middle engine C being marked by the dotted
line and that of the aft engine being indicated by the line 8) that of the middle
engine being inclined to the left and that of the aft engine to the right of the
vertical central line t of the ship.
H indicates the main steam-pipe, and KK the pipes leading the steam from the
high-pressure cylinder B to the low-pressure cylinders C D.
As the pistons and rods, slide-valves and excentrics, and other parts are of
known construction and need no explanation the description of the Drawings has
been restricted to the new features of the Invention.
Condensers and pumps are not shown in the Drawings seeing that of late they
are often fitted separately in convenient places, and that they do not form a part of
the present Invention.
This arrangement can be applied to direct-acting and various other forms of
horizontal engines as well as to the horizontal lever engines shown in the
accompanying Drawings; it is also applicable to simple expansion compound engines.
Since the shafts of the latest twin screw vessels are placed comparatively close
together the horizontal" grasshopper" form appears to be most suitable requiring
less space athwartship than other forms, the side levers standing midship with their
fulcrum below, at the same time giving sufficient length of crank and long
connecting rods.
The Drawings show the application of the said Invention to a compound engine
of the horizontal lever form of. about 6000 indicated horse power having one high
pressure cylinder of 65" and two low pressure cylinders of 85" diameter and
63" stroke of piston with cranks of 21" length, being equal to two sets of
compound engines each of them having a high pressure cylinder of 54" and a low
pressure cylinder of 100" by 45" stroke of piston.
Although, as said before, this method of coupling and driving the shafts of twin-
screw-vessels can be applied to different forms of engines the horizontal lever form
is of all horizontal forms that which requires the smallest distance between the
shaft centres and allows of a more favourable proportioning of cylinders, reducing
the diameter and increasing the length without requiring to exceed the reasonable
limits of the speed of the piston. The centres of the shafts can be situated as low
and the cranks be as long as in the vertical hammer engine, and the above
described horizontal form of engine appears to be unrivalled for war ships since the
highest part of the machinery situated midships is still considerably (4 to 5 feet);

page_text: below the water line, and towards the sides nothing interferes with adapting the
most efficient position and curve of armour plated decks.
•
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
First. The method of coupling and driving the shafts of twin screw vessels by a
single set of engines having at least three cylinders, one of which carries one or
two connecting rods at each end or one connecting rod at one end and two at the
other end, the other cylinders carrying one or two connecting rods at one end only;
and without wheel gearing or additional rods or levers for coupling.
Second. The arrangement of the horizontal lever type of engine with the fulcrum
of the side levers below the cylinders for driving the shafts of twin screw vessels,
substantially as described.
HASELTINE, LAKE & Co.,
For the Applicant.