IMPROVEMENTS IN SCREW PROVISIONAL SPECIFICATION
Year: 1874

page_text: LETTERS PATENT to Edward James Reed, Companion of the Bath,
of 8, Victoria Chambers, Westminster, in the County of Middlesex,
Naval Constructor, for the Invention of “IMPROVEMENTS IN SCREW
PROVISIONAL SPECIFICATION left by the said Edward James Reed
at the Office of the Commissioners of Patents, with his Petition,
on the 22nd July 1874.
I, EDWARD JAMES REED, Companion of the Bath, of 8, Victoria
Chambers, Westminster, in the County of Middlesex, Naval Constructor,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN SCREW PROPELLERS, AND IN THE PROPULSION OF VESSELS," to be as follows:-
My Invention consists in forming screw propellers of two separate
parts of different diameters and capable of being driven independently,
but by the same engines, by the same primary engine shaft, and at about
the same axial line; and in working both parts, or the part of large

page_text: diameter only, in deep water at sea, butonly the part of smaller diameter
in crossing harbour bars, or in other shallow waters, the part of large
diameter being then placed with its blades horizontal, and thus kept
clear of the bottom. I prefer to pass the driving shaft of one part of
the screw through the driving shaft of the other part, made tubular for
the purpose, but I do not confine myself to this arrangement, nor do
I limit myself to placing the two parts of the screw in immediate
proximity to each other, as they may be separated to any distance to
suit special requirements.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward James Reed in the Great Seal Patent
Office on the 22nd January 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
JAMES REED, Companion of the Bath, of 8, Victoria Chambers, West-
minster, in the County of Middlesex, Naval Constructor, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of July, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and
Her
successors, give and grant unto me, the said Edward James Reed,
special licence, that I, the said Edward James Reed, my executors,
administrators, and assigns, or such others as I, the said Edward
James Reed, 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 Inven-
tion for "IMPROVEMENTS IN SCREW PROPELLERS, AND IN THE PROPULSION. OF
VESSELS," upon the condition (amongst others) that I, the said Edward
James Reed, 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 immediately after the date of the said Letters Patent.

page_text: -
NOW KNOW YE, that I, the said Edward James Reed, 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 thereof, that is to say: —
My Invention consists in forming screw propellers of two separate
parts of different diameters, and capable of being driven independently,
but by the same engines, by the same primary engine shaft, and about
the same axial line; and in working both parts, or the part of large
diameter only, in deep water at sea, but only the part of smaller diameter
) in crossing harbour bars, or in other shallow waters, the part of large
diameter being then placed with its blades in such horizontal, or other
position, as to be kept clear of the bottom. I prefer to pass the driving
shaft of one part of the screw through the driving shaft, of the other
part, made tubular for the purpose, but I do not confine myself to this.
5 arrangement, nor do I limit myself to placing the two parts of the
screw in immediate proximity to each other, as they may be separated
to any distance to suit special requirements.
One method of carrying my Invention into practice is represented in
the annexed Drawings.
1 Figure 1 is a profile view of the stern of a ship; the boss of the
propeller is here formed in two separate parts A and B, which may
work together or independently; the one portion of the boss carries a
propeller of larger diameter, and the other portion a propeller of smaller
diameter, in this case of such smaller diameter as to sweep a circle
5 whose periphery shall not be deeper below the water line than the heel
of the stern post. The one portion of the boss B in this arrange-
ment driven by an annular or sleeved shaft embracing a shaft of lesser
diameter, which drives the other portion of the boss A. These shafts
may, by simple and well known arrangements of friction clutches or
› bolted flanges, be worked together or separately, as may be consistent
with the depth of water in which the ship floats.
My Invention may be fitted to existing ships or to new vessels, and
in either case the usual screw aperture may be adapted, the horizontal
keel piece being omitted, and the rudder post (which would usually
require to be much strengthened) terminated at a distance sufficiently
high above the axial line of the shaft to admit of the propellers being
drawn off or placed upon the shaft in the most convenient manner.

page_text: .
The space below the end of the rudder post D may be either left open or.
utilized for the application of a separate and removable rudder piece F
bolted to the main portion of the rudder E, thus converting it into a
balanced rudder.
In Figure 2 is shown another arrangement of my Invention, in which
I place the two parts of the screw propeller at such a distance apart
that the rudder may be introduced between them. In this arrangement
the tubular or sleeved shaft drives the part of the propeller of smaller
diameter blades, but I reserve to myself the right of placing the larger
diameter blades or the smaller diameter blades upon the smaller or solid
shaft or upon the tubular or sleeved shaft, as may be most expedient.
I do not confine myself to the above described arrangements, as they
may be varied in many ways without departing from the substance of
my Invention.
Having thus described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim, the
Invention of forming and working screw propellers of two separate
parts of different diameters, each part being capable of being driven
independently from or by the same engines, as and for the purposes
herein-before set forth.
In witness whereof, I, the said Edward James Reed, have here-
unto set my hand and seal, this Fourteenth day of January,
ad night hundred and