IMPROVE- MENTS IN SCREW PROPELLERS
Year: 1885

page_text: I, BENJAMIN DICKINSON, of The Elms, Bourne End, in the County of Bucks,
East India Merchant, do hereby declare the nature of my invention for "IMPROVE-
MENTS IN SCREW PROPELLERS " to be as follows:-
My invention has reference to an arrangement of screw propeller wherein the
blades are arranged in sets or series in such a manner that the blades of each set
or series shall operate independently and successively so that no two blades act
upon the same water. To this end the blades of each set or series (which may be
two or more in number) are arranged upon the boss in a spiral direction contrary
to the direction of the inclination of the blades themselves. Thus, when the
propeller is in operation to drive the vessel forward, the rearward blade travels in
advance of the succeeding blade which in its turn (where more than two are used
in the set or series) travels in advance of the next forward blade and so on,.
relatively.

page_text: I, BENJAMIN DICKINSON, of The Elms, Bourne End, in the County of Bucks,
East India Merchant, 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:—
My invention has reference to an arrangement of screw propeller wherein the
blades are arranged in two or more sets or series in such a manner that the blades
of each set or series shall operate independently successively and continuously so
that no two blades of any one set shall act upon the same water. To this end the
blades of each set or series (which may be two or more in number) are arranged
upon the boss or shaft in a spiral direction contrary to the direction of the inclina-
tion of the blades themselves. Thus, when the propeller is in operation to drive
the vessel forward, the rearmost blade travels in advance of the succeeding or next
blade which in its turn (where more than two are used in the set or series) travels
in advance of the next forward blade and so on. relatively, the arrangement being
Buch that no two blades in one set or series shall operate upon the same water, and
that the water acted upon may readily escape.
Referring to the accompanying sheet of drawings Fig. 1 is an elevation of the
forward end of a propeller according to this invention, and Fig. 2 is a view at
right angles to Fig. 1, shewing the propeller as seen when looking in the direction
of the arrow ①. → In this case the propeller is provided with two sets or series
of blades there being three blades in each set or series. The blades marked A. A
occupy the aftermost position, that is, they are nearest to the rearmost extremity
. of the propeller shaft; those marked B, B occupy a more forward position, while
those marked C. C are the most forward of the three. For forward motion of the
vessel, the propeller revolves in the direction of the arrows ② → the leading
blades (considered with reference to the circle of rotation) being A. A, and the
others following in their order.
By this arrangement each blade is caused to operate on a distinct portion of the
body of water through which the vessel passes, while a free channel is provided
for the escape astern of the water operated upon. The blades may be of any
suitable pitch breadth or pattern and may be made in one piece or in sections as
may be convenient.
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. Arranging the blades of a screw propeller upon the shaft or boss in two or
more spirals each having a pitch or inclination of the opposite hand or denomina-
tion to that of the individual blades composing the spiral set or series, so that the

page_text: rear most blade of each set or series travels in advance of the succeeding or next
forward blade of the same set or series, which in its turn (where more than two
are used in a set or series) travels in advance of the 'next forward blade, and so
on, the arrangement being such that no two blades in one set or series operate
upon the same water, and that water acted upon may readily escape, substantially
as hereinabove described.
2. The improved screw propeller constructed, arranged and operating substan-
tially as shewn in and described with reference to the drawings.
Dated this 18th day of September 1885.
B. DICKINSON.
W. Lloyd Wise,
46, Lincoln's Inn Fields, W.C.,
Applicant's Agent.