Improved Screw Propellers for Steam Ships and Boats.
Year: 1896

page_text: Date of Application, 4th May, 1896
Complete Specification Left, 17th Nov., 1896-Accepted, 13th Feb., 1897
PROVISIONAL SPECIFICATION.
Improved Screw Propellers for Steam Ships and Boats.
I, FRANCIS WAKEFIELD, of 46 Payson Street Birkenhead, Cheshire England,
Ship Joiner and Pattern Maker do hereby declare the nature of this invention to
be as follows:-
The invention consists in longitudal blades twisted to form screws, and fastened
to shafts by flanges or lugs, by bolts, and made to fit clear of ships sides, as near
as convenient for about three fourths the length between, stuffing box in hull, to
hanger stay for carrying end of shaft, opposite rudder post, and fastened to stern
post, and under ships stern sides.
The result being, the blades having a greater grip, they do not disturb the water
to the extent of old propellers, and drives the ship a great deal faster.
FRANCIS WAKEFIELD,
46 Payson Street, Birkenhead.
Improved Screw Propellers for Steam Ships and Boats.
I FRANCIS WAKEFIELD of 46 Payson Street Birkenhead, Cheshire, England,
Ship Joiner and Pattern Maker, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention has reference to screw propellers for navigable vessels, and
consists of a certain construction, by which an efficient propelling effect is
obtained, the propeller having a good grip of the water, and working with little
disturbance.
According to this invention, the propeller is formed of a longitudinal blade or
blades, twisted or traced in one or more threads in the form of a screw, and con-
nected to a propeller shaft, and adapted, in the case of twin screws, to fit on each
side of the after run of the vessel, between the stuffing boxes in the hull, and the
usual supporting bracket.
The annexed drawings are illustrative of the invention, Figure 1 being a side
elevation, shewing a screw propeller, according to this invention, fitted as a twin
screw to a vessel. Figure 2 is an eud view shewing both screws, and Figure 3 is a
Bection of the screw taken at A A, Figure 1.
In the examples illustrated, the screw has double blades a a', formed by tracing
a double thread round a common centre b, the blades being made to taper forward,
so as to lie clear in the vessel's run, between the stern tube stuffing box at e, and
the stern bracket d. e designates the propeller shaft. The blades a a' are formed
with their after or gripping sides h concave or hollowed, to afford a better grip on
the water. The forward sides of the blades are convex, with the edges rounded or
turned hack no at i

page_text: In construction, the blades a a' can be made to any required pitch, and can be
either cast or forged in sections, or in one twisted sheet of metal, and connected
to the propeller shaft e by flanges and bolts, or by other known suitable means.
By this invention, a propeller is provided which has a good grip of the water,
a large propelling surface, and does not disturb or break up the water to any great
extent.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described improvement in screw propellers, consisting in having
or constructing the blade or blades twisted or traced in one or more threads, and
adapted to lie in the run of the vessel; as and for the purposes specified.
2. The screw propeller, constructed particularly as set forth with reference to
and shewn in the drawings hereto annexed.
1000
FRANCIS WAKEFIELD,
46 Payson Street, Birkenhead, Cheshire, England.