IMPROVEMENTS IN THE CONSTRUC
Year: 1880

page_text: LETTERS PATENT to Alfred Fildes, of Lake Side, Ulverston, in the County of
Lancaster, for an Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
LETTERS PATENT to Alfred Fildes, of Lake Side, Ulverston, in the County of
Lancaster, for an Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
APPARATUS USED FOR PROPELLING VESSELS."
PROVISIONAL SPECIFICATION left by the said Alfred Fildes at the Office
of the Commissioners of Patents on the 2nd June 1880.
"
ALFRED FILDES, of Lake Side, Ulverston, in the County of Lancaster.
IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS USED FOR PROPELLING
VESSELS."
This Invention relates to the construction and arrangement of the steam engines
used for propelling vessels with twin screws, the object of the Invention being to
drive each screw with a single cylinder steam engine, and to prevent the possibility
of either engine stopping on the "dead centre."
The two single cylinder engines are arranged side by side, each coupled to and
driving its own propeller shaft by means of a crank, the cranks being set at about
right angles to each other.
In addition to these ordinary cranks I have an auxiliary crank upon each
propeller shaft (by preference these are disc cranks), the crank on the shaft being
set at or near right angles to its corresponding steam crank, and that on the other
shaft being opposite to its corresponding steam crank, that is, in a line with it on
the opposite side of the centre.
Between the two shafts I mount a lever or beam having a fulcrum at the centro,
each end being of the same length, and connect each end by a rod or link with
one of the auxiliary crank pins before named.
Thus it will be seen that the two single cylinder engines are coupled or connected
together in such a manner, that when one is at the full stroke or "dead centre"
the other is always at half stroke, and consequently steam being admitted to both
cylinders at once, should one engine be at the "dead centre "the other will be at
its most effective point or "half stroke," and will consequently immediately pull it
off the "dead centre."
By this arrangement all the advantages of double cylinder engines will be
secured at the same time that single cylinder engines only are used, which are of
course much more economical both as to their cost, and also the smaller space
which they occupy in the vessel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Fildes in the Great Seal Patent Office on the 2nd December
1880.
ALFRED FILDES, of Lake Side, Ulverston, in the County of Lancaster.
"IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS USED FOR PROPELLING
VESSELS."
This Invention relates to the construction and arrangement of the steam engines
used for propelling vessels with twin screws, the object of the Invention being to
drive each screw with a single cylinder steam engine, and to prevent the possibility
of either engines stopping on the "dead centre."
Such being the nature and object of my said Invention, I will now proceed to
describe in detail the manner in which the same is to be or may be performed or
carried into practical effect; and in order that the same may be clearly understood I
have annexed hereunto a Sheet of Drawings illustrative thereof, and have marked the
same with figures and letters of reference corresponding with those in the following
explanation thereof :-
Fig. 1 in the annexed Drawing is a plan view, and Fig. 2 an elevation of a pair
of single cylinder engines constructed and arranged according to my Invention.
The two single cylinder engines a, a, and b, b, are arranged side by side, each
coupled to and driving its own propeller shaft c, c, and d, d, by means of a crank
ff, and g, g, the cranks being set at about right angles to each other.
In addition to these ordinary cranks I have an auxiliary crank h, h, i, i, upon
each propeller shaft c, c, and d, d (by preference these are balanced, or they may be
disc cranks as drawn), the crank h, h, on one shaft c, c, being set at or near right
angles to its corresponding steam crank, and that i, i, on the other shaft d, d, being
nearly in a line with its corresponding steam crank.
Between the two shafts c, c, and d, d, I mount a lever or beam k, k, having a
fulcrum at the centre, and each end being of the same length, and I connect each
end by a rod or link m, m, with one of the auxiliary crank pins h, h, and i, i,
before named.
Thus it will be seen that the two single cylinder engines a, a, and b, b, are
coupled or connected together in such a manner that when one is at the full stroke
or "dead centre" the other is always at half stroke, and consequently steam being
admitted to both cylinders at once, should one engine be at the "dead centre" the
other will be at its most effective point or half stroke," and will consequently
immediately pull it off the "dead centre;" n, n, are the valves; o, o, the steam
supply pipe, and p, p, the reversing gear.
"
By this arrangement most of the advantages of double cylinder engines will be
secured at the same time that single cylinder engines only are used, which are of
course much more economical both as to their cost, and also the smaller space which
they occupy in the vessel.
Having now described the nature and object of my said Invention, together with
the manner in which the same is to be or may be performed or carried into
practical effect, I wish it to be understood that I claim as my Invention, the
construction and arrangement of two single cylinder engines for driving the
propeller shafts of twin screw vessels, substantially as hereinbefore described and
illustrated by the Drawing annexed.
In witness whereof, I, the said Alfred Fildes, have hereunto set my hand
and seal, this 26th day of November, in the year of our Lord One thousand
eight hundred and eighty.
ALFRED FILDES. (L.S.)