IMPROVEMENTS FOR PREVENTING THE FOULING BY AND CLEARING SHIP'S PROPELLERS FROM ROPES
Year: 1866

page_text: LETTERS PATENT to Richard Harvey Hudson, of Glasgow, in the County
of Lanark, North Britain, for the. Invention of "IMPROVEMENTS FOR PRE-
Sealed the 19th February 1867, and dated the 28th August 1866.
PROVISIONAL SPECIFICATION left by the said Richard Harvey Hudson
at the Office of the Commissioners of Patents, with his Petition, on the
28th August.1866.
I, RICHARD HARVEY HUDSON, of Glasgow, in the County of Lanark, North
Britain, do hereby declare the nature of the said Invention of "IMPROVEMENTS
FOR PREVENTING THE FOULING BY AND CLEARING SHIP'S PROPELLERS FROM ROPES,"
to be as follows, that is to say :-
This Invention consists in fixing a metallic disc to the rudder port at the
part where the boss for the screw shaft bearing is situated and aft the screw;
the entire edge of this case being formed sharp. The action of this in
preventing the fouling of propellers by ropes is as follows:-As soon as a rope
becomes entangled with the screw and its shaft, the revolution of the screw
causes the rope to be wound thereon, and this action brings the rope at once
in contact with the cutting edge above referred to the winding of the screw
each instant drawing the rope tighter over the sharp edge the rope is at once
cut in half so that by means of this Invention a rope can never be entangled
over the screw by more than three or four revolutions. The upper and lower

page_text: edges of the disc are formed with horns on them so as to assist in catching the
rope for the cutting action to take place, and the entire circumference of the
disc may
be formed with a scolloped edge for the purpose of rendering its
action more efficient.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Harvey Hudson in the Great Seal Patent Office
on the 20th February 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
HARVEY HUDSON, of Glasgow, in the County of Lanark, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of August, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Richard
Harvey Hudson, Her special licence that I, the said Richard Harvey Hudson,
my executors, administrators, and assigns, or such others as I, the said Richard
Harvey Hudson, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the. United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS FOR
PREVENTING THE FOULING BY AND CLEARING SHIP'S PROPELLERS FROM ROPES," upon
the condition (amongst others) that I, the said Richard Harvey Hudson, by
an instrument in writing under my hand and seal, should particularly describe
and ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
.
NOW KNOW YE, that I, the said Richard. Harvey Hudson, 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, reference being had to the accompanying Drawings and to the
letters and figures marked thereon, that is to say:-
.
My said Invention consists in fixing a metallic disc to the rudder post at
the part where the boss for the screw shaft bearing is situated and aft the
screw, the entire edge in this case being formed sharp. The action of this in

page_text: preventing the fouling of propellers by ropes is as follows:-As soon as a rope
becomes entangled with the screw and its shaft the revolution of the screw
causes the rope to be wound thereon, and this action brings the rope at once
in contact with the cutting edge above referred to, the winding of the screw
each instant drawing the rope tighter over the sharp edge the rope is at once
cut in half, so that by means of this Invention a rope can never be entangled
over the screw by more than three or four revolutions. The upper and lower
edges of the disc may be formed with horns on them so as to assist in catching
the rope for the cutting action to take place, and the entire circumference of
the disc may be formed with a scolloped edge for the purpose of rendering its
action more efficient.
And in order that my said Invention may be properly understood, I shall
now proceed more particularly to describe the system, mode, or manner in or
under which the same is or may be used or practically carried into effect,
reference being had for the sake of more complete elucidation to the several
Figures upon the explanatory Sheet of Drawings which I have hereunto
appended, that is to say,-
Figure 1 is a side elevation of the stern. post of a vessel propelled by a
screw. The hull proper is marked A, and in it the usual opening B for the
reception of the screw C is formed in the ordinary manner. The screw shaft D,
which carries the screw C, is supported in suitable bearings in the inner and
outer stern posts E and F and at the parts of these a and b which are
increased in, dimensions to allow of the passage therethrough of the screw
shaft D, the cutting discs G and H are fixed by bolts c. The discs G and H
are each made in two halves as more particularly seen in Figure 3, and in
section at Figure 4, the object of making them in two pieces being that they
may be taken off to be ground or otherwise sharpened without the necessity
of withdrawing the screw shaft by merely taking out the screw bolts c.
Figure 2 is a perspective view of the same parts of a ship corresponding to
Figure 1, and in the several parts of which similar Letters of reference are
marked as on the preceding Figure so that the portion of this Specification
descriptive of Figure 1 equally applies to Figure 2, and therefore need
not be repeated. The action of the cutter or cutting disc is evident from
Figures 1 and 2 in which the screw is shown in the act of being fouled by a
rope or hawser I, the two Figures showing the rope caught upon opposite
sides of the rudder post, from which it is clear that as the screw revolves the
rope is drawn tighter over the cutting edge of the disc. As before stated the
edges of the discs may be formed with horns or projections thereon or they
may be scolloped if desired with the view of assisting the cutting action, but

page_text: from the experiments I have made I find that the plain circular disc com-
pletely prevents fouling of the screw by ropes.
Having now described the nature of my said Invention, and the manner in
which the same is or may be used or practically carried into effect, I would
observe in conclusion that what I consider novel and original and therefore
claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, the application of a cutting disc or discs to the stern-posts
of vessels propelled by screws for the purpose of cutting ropes or hawsers that
may become entangled with the screw, thereby preventing the fouling of the
screw.
In witness whereof, I, the said Richard Harvey Hudson, have hereunto
set my hand and seal, this Fifteenth day of February, One thousand
eight hundred and sixty-seven.
RICHARD HARVEY HUDSON. (L.B.).
Witness,
St. JOHN VINCENT DAY, C. E.
Patent Offices,
166, Buchanan St.
'Glasgow..