ATHDRAWER SUPMPERARD PROBELLOP FOR NAVIGABLE VESSELS
Year: 1867

page_text: LETTERS PATENT to Isaac Dixon, of the Firm of Dixon and Sleight, of
Liverpool, in the County of Lancaster, Contractors, for the Invention of
"ATHDRAWER SUPMPERARD PROBELLOP FOR NAVIGABLE VESSELS"
Sealed the 28th February 1868, and dated the 30th August 1867.
PROVISIONAL SPECIFICATION left by the said Isaac Dixon at the
Office of the Commissioners of Patents, with his Petition, on the
30th August 1867.
I, ISAAC DIXON, of the Firm of Dixon and Sleight, of Liverpool, in the.
County of Lancaster, Contractors, do hereby declare the nature of the said
Invention for "AN IMPROVED SUBMERGED PROPELLOR FOR NAVIGABLE. VESSELS," to
be as follows (that is to say) :-
To construct a propeller according to this Invention the boss or nave may
be egg or oval shaped, from which spring two or more flat or nearly flat blades
set at the required angle to the driving shaft on which the propeller is mounted..
When these blades are made of plates of sheet metal it is preferred they
should be tapered or chamfered off at one or both sides of the outer edges'so
as to form feather or sharp edges on the outer rims of the blades, and when.
the propeller or blades thereof are constructed from cast metal, to ensure
strength and easy evolution in the water it is preferred to form the back and
front surfaces of the blades slightly convex that they may have sharp edges, and
the body of the metal of which they are formed placed. in. the best position to.

page_text: insure the maximum mechanical strength in the amount of material employed,
and at the same time present the least possible resistance to their evolution in
It must be clearly understood that the form of the blades when
tapered off at the outer edges equally on both sides may be each mathe-
matically divided into two parts by a perfect plain or straight cut made at
a right angle to the shaft, and parallel to the set or pitch of the blades,
thus dividing the blades into two equal or nearly equal parts. The propeller
blades may be constructed and fixed on the boss at any desired angle to meet
the circumstances and coustruction of the vessel to which the particular
propeller is to be applied, and is keyed on or otherwise attached to the driving
shaft in the ordinary manner in which screw propellers are usually connected
to their shafts.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Isaac Dixon in the Great Seal Patent Office on the
28th February 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ISAAC
DIXON, of the Firm of Dixon and Sleight, of Liverpool, in the County of
Lancaster, Contractors, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of August, in the year of our Lord One
thousand eight hundred and sixty-seven, in the thirty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Isaac Dixon, Her special license that I, the said Isaac Dixon, my
executors, administrators, and assigns, or such others as I, the said Isaac
Dixon, my executors, administrators, and 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 "AN IMPROVED
SUBMERGED PROPELLER FOR NAVIGABLE VESSELS," upon the condition, (amongst
others), that I, the said Isaac Dixon, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
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 imme-
diately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Isaac Dixon, do hereby declare that the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
To construct a propeller according to this my said Invention the boss or
nave may be oval shaped or egg ended, from which spring two or more flat or.
nearly flat blades set at the required angle to the driving shaft on which the
propeller is mounted. When these blades are made from plates of sheet
metal it is preferred they should be tapered or chamfered off at one or both
sides of the outer edges so as to form feather or sharp edges on outer rims of the
blades, and when the propeller or blades thereof are constructed of cast metal
to ensure strength and easy evolution in the water it is preferred to form the
back and front surface of the blades slightly convex that they may have sharp
edges, and the body of the metal of which they are formed placed in the best
position to ensure maximum mechanical strength in the amount of the material
employed, and at the same time prevent the least possible resistance to their
evolution in the water. I wish it to be clearly understood that the form of
the blades when tapered off at the outer edges equally on both sides, may be
each mathematically divided into two parts by a perfect plain or straight cut
made at a right angle to the shaft radially, and parallel to the set or pitch of
the blades, thus dividing the blade into two equal or nearly equal parts. The
propeller blades may be formed in outline to resemble an ordinary screw
propeller, or may partake of an oval or partially circular cantour or other
convenient form. The propeller blades may be constructed at any desired
angle to meet the circumstances and construction of the vessel to which the
particular propeller is to be applied, and is keyed on or otherwise attached to
the driving shaft in the ordinary manner in which screw propellers usually are
connected to their shafts.
That this my said Invention may be the more readily seen and understood,
I have hereunto annexed Drawings illustrating my Invention as applied to a
two-bladed propeller. Like letters marked thereon being used to denote
similar parts.
Figure 1 is a back elevation, and Figure 2 a side elevation; Figure 3 is a
vertical section, showing the mode of distributing the metal; Figure 4 is a
top view or plan showing the angles of the blades.
A, blades; B, oval boss; C, driving shaft.
Having now fully described and ascertained the nature of this my said
Invention, and the best means I am acquainted with for carrying the same
into practical effect, I wish it to be understood that I do not confine myself to

page_text: the relative proportions or dimensions of the several parts, as it will be readily
seen the same may be considerably varied without departing from the Inven-
tion; but what I claim as new and my Invention is, the construction and use
of propellers for navigable vessels, constructed substantially in the manner
herein-before described and set forth.
In witness whereof, I, the said Isaac Dixon, have hereunto set my hand
and affixed my seal, this Twenty-seventh day of February, in the year
of our Lord One thousand eight hundred and sixty-eight.
Witness,
WILLIAM WALKER,
of 44, Castle Street,
Liverpool.
ISAAC (L.s.) DIXON.