Improvements in Propellers.
Year: 1894

page_text: of Application, 19th June, 1894-Accepted, 21st July, 1894
Improvements in Propellers.
I, HUBBELL DUANE HURLBUT, of 2 Quai Des Eeaux vives, Geneve,
Switzerland, Inventor, 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:-
The object of this invention is to provide a propeller of simple, strong and
durable construction, and great in efficiency.
The invention consists in the improved propeller, and in the combination and
arrangement of the various parts thereof, substantially as will be hereinafter more
fully described and claimed."
Referring to the accompanying drawings in which like letters of reference
indicate corresponding parts in each of the several figures.
Fig. 1, is a side elevation of my improved propeller, and Fig. 2, an end view of
the same.
In said drawings a represents a propeller shaft upon which is firmly secured a
hubby means of the collars c or in any desired manner. Said hub may be solid
or hollow and is of elliptical shape, the highest point in the centre and gradually
tapering towards its outer ends as clearly shown in the drawings.
e
To the outer periphery of said hub are firmly secured in any desired manner a
series of independent segmental spiral blades d (in the drawing three), forming a true
screw, which constitutes the propelling medium. These blades are so constructed,
that while the line of the outer edge of each blade d is almost straight, the line
at the base or connection with the hub is curved (substantially S shaped) as shown
at /.
From the foregoing it may be seen, that the blades are so twisted and
arranged, that all their radial lines, at every point, are at right angles to the
periphery of the hub.
By preference, the blades are of such dimensions, that when viewed from either
end, will just cover the area of a complete circle, see Fig. 2.
When the propeller is in use the elliptical hub acts as a deflector to direct
the water towards the blades; the water, as acted upon by the blades, is not thrown
off centrifugally as in ordinary constructions, but is thrown directly backward and
thus all possibility of churning is avoided, and all loss of power by centrifugal force
obviated.
By the use of a series of propeller blades, constructed as described, and forming
a true screw, and being at the same time independent of each other in distinction
from a continuous blade, the power of the propeller is greatly increased, which is
due to its comparatively large propelling surface.
I do not intend to limit myself to the precise construction shown and described,
as various alterations can be made, without changing the scope of my invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A screw propeller composed of an elliptical hub and of a series of segmental
blades, so arranged on said hub, as to form a true screw, substantially as described.
2. A screw propeller composed of an elliptical hub and of a series of segmental
blades forming a true screw secured to said hub, and having their outer edges
approximately straight and their bases curved or bent, substantially as described.
3. In a screw propeller the combination with the elliptical hub, of a propelling
blade with approximately straight outer edge and curved base, the radial lines of

page_text: Enid blade being at all points at right angles to the periphery of the hub,
substantially as described.
Datad this 10th day of June 1801
J. P. BAYLY,
18, Fulham Place, W., Agent for the Applicant.