improvements in screw-propeners.
Year: 1899

page_text: Date of Application, 24th May, 1899
Complete Specification Left, 5th Feb., 1900-Accepted, 10th Mar., 1900
improvements in screw-propeners.
I, RUDOLF COUNT WESTPHALEN, of 33A, Rennweg, Vienna III., in the Empire
of Austria, Gentleman, do hereby declare the nature of this invention to be as
follows:-
-
This invention relates to propellers acting on the principle of the screw, and
it has for its object to provide a propeller producing a closer stream of water
projected in the direction opposite to that of the required motion of the vessel
than is produced by known screw-propellers, in which two or more helical or
plane blades are connected with a boss.
According to my invention, two or more plane, circular or elliptic blades are
directly connected with each other so as to have their planes intersecting each
other, and from the centres of the said circular or elliptic blades, short bars run
to the boss, to which their free ends are secured in any suitable manner.
Dated this 24th day of May 1899
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
I, RUDOLF COUNT WESTPHALEN, of 33A, Rennweg, Vienna III., in the Empire
of Austria, Gentleman, do hereby declare the nature of my said invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement: -
This invention relates to propellers for vessels acting on the principle of the
screw, that is to say in which a number of inclined blades are secured to a
revolving shaft, which is arranged parallel with the keel of the vessel, the said
blades projecting a mass of water in a direction opposite to that of the required
motion of the vessel.
The speed of a vessel thus propelled is the result of the reaction of the mass of
water projected backwards, and the amount of reaction directly depends on the
mass of the moving water and on its velocity. Now my invention has for its
object to increase the mass of water simultaneously in motion by doing away
with one of the causes, by which, with ordinary screw propellers, the ris riva of
the moving particles of water is prematurely absorbed.
This cause is the current of water drawn after it by the bosses of screw pro-
pellers of the usual construction, the said current being in frictional contact with
the stream lines of the current projected sternwards by the propeller blades.
According to my invention, the propeller is so constructed that the boss, by

page_text: means of which it can be connected to the driving shaft, is not arranged between
the blades, but in front of them. Two or more suitably inclined flat blades, by
preference of circular shape, are so arranged, side by side, as to touch each other
with one point of their circumferences, and from a suitably chosen point of the
rear faces or the said blades, converging bars extend to the boss, for connecting
the blades with the boss.
In order that the connecting bars, instead of creating a detrimental resistance
by their rotation within the water shall assist in producing the sternwardly
directed curent of water, the said bars are flattened and arranged with such
inclinations toward the axis of the boss as to act as propeller blades.
In order to enable the invention to be fully understood, the same is herein-
after described with reference to the accompanying drawing, in which:-
Figure 1 is a side elevation of a two-blade propeller of the construction referred
to above.
Figure 2 is a rear elevation, and
Figure 3 a top view of the same.
It will be seen that the two circular blades a, a have flat rear faces, while the
front faces are somewhat convex or rounded in order to give all portions the
requisite strength. It is obvious, however, that the front faces can be made
flat and the rear faces convex.
The blades a, a touch each other at a point b of their circumferences, and are in
opposite directions inclined toward the axis of the boss d. In the case of three
or more blades, the same would have the positions of symmetric tangential planes
to supposed equidistant helical blades.
From the centres of the blades a, a, the converging bars c, c, extend to the
boss d. These bars c, c are flattened, and as may be inferred from their lines of
intersection with the surface of the boss, they are so inclined toward the axis of
the boss, that, when turning, they set the water in motion in a similar manner to
the blades a, a. The positions of these flattened bars c may be defined as those of
symmetric tangential planes to as many equidistant helical surfaces, generated by
generatrices, which are inclined toward the axis of the supposed cylindrical core.
For the purpose of reducing the resistance to the movement of the bars c in the
lateral direction, the said bars have their front faces rounded, whereby sharp
edges are obtained.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a screw propeller, the combination with a plurality of flat blades, having
the positions of symmetric tangential planes to as many equidistant helical blades,
and being so arranged side by side as to touch each other at one point, of a boss
located in front of the said point, and converging bars, which connect a point of
the front face of each blade with the boss, substantially as, and for the purpose
described.
2. In a screw propeller, the combination with a plurality of circular flat blades,
having the positions of symmetric tangential planes to as many equidistant helical
blades, and being so arranged side by side as to touch each other at one point of
their circumferences, of a boss located in front of the said point, and converging
bars, which connect the centres of the front faces of the said blades with the boss,
substantially as and for the purpose set forth.
Dated the 5th law of
1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.