Year: 1886

page_text: I COTESWORTH PINCKNEY WETHERILL of Woodville in the County of Wilkinson
and State of Mississippi, United States of America, Mechanical Engineer 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 consists in a screw-propeller or propelling wheel having its
blades, of which two or more may be used, set inclining in the direction of their
length relatively to the axial line of the shaft, of the wheel and forwardly in the
direction of the motion ahead produced by the propeller and of an effective angle
of pitch with said shaft, the plane of which inclination of the said blades crosses the
said axial line of the wheel shaft, substantially as hereinafter more fully set forth
and pointed out in the claim.
Reference is to be had to the accompanying drawings forming a part of this
Specification in which figure 1 represents a face view of a two bladed propelling
wheel embodying my Invention, and figures 2 and 3 side views of the same as seen
from different positions at right angles with each other. Similar letters of reference
indicate corresponding parts in all the figures.
A is the hub of the wheel, the dotted line 6 indicating the axial line of its shaft.
BB are the blades, which, instead of projecting in a direction at right angles to
the axial line of the shaft as in other screw bladed propellers, are set inclining in
direction of their length relatively to said axis so as to occupy a forwardly inclining
position towards the shaft in direction of the motion ahead produced by the
propeller. This inclination of the propeller blades relatively to the axial line of
the shaft causes the blades to rotate within a space which, if circumscribed, would
be represented by the figure of a cone. Such inclination may vary from forty to
sixty degrees (40° to 60°) and the pitch of the blades I find most effective when
the same is at an angle with the shaft varying from forty-five to sixty-five
degrees (45° to 65°) or thereabouts. The inclination of the blades in direction of.
their length relatively to the axial line of the shaft causes the wheel, for a given
diameter, to have a greater propelling area than is attainable by propelling wheels
of the ordinary construction, using blades of like width and pitch, whereby greater
speed may be obtained for a given number of revolutions. There will also be less
alip as well as increased thrust and the wheel, for a given area of propelling surface,
will have a greater body of water over it when submerged.

page_text: Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed, I declare that what
I claim is
The screw propeller, or propelling wheel having its blades of suitable pitch set
inclining in the direction of their length relatively to the axial line of the shaft of
the wheel and forwardly in the direction of the motion ahead produced by the
propeller, the plane of which inclination of said blades crosses the said axial line of
the wheel shaft, substantially as and for the purposes set forth.