Improvements in Screw Propellers for Navigable Vessels.
Year: 1888

page_text: Date of Application, 23rd Nov., 1888
Complete Specification Left, 22nd Aug., 1889-Accepted, 28th Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in Screw Propellers for Navigable Vessels.
I, GIOVANNI CUSTANTE PARINI, of 156 Dale Street, Liverpool, in the County of
Lancaster, Restaurateur, do hereby declare the nature of my said invention to be as
follows:-
My invention relates to screw propellers for Navigable Vessels, and has mainly for
its object to enable the water to pass freely from the propeller blade at the root of the
blade instead of being churned round and disturbed, as is the case with the common
construction of screw propeller.
To the above ends and according to my invention I construct the blades (of which
there may be two or more on the boss, which may be of the usual kind) with a
differential pitch, that is to say, I give the blade a fine pitch at the root and a full or
coarse pitch at the extremity. The blades may be straight or set back, and they may
be set on the boss at their root, so as to leave a channel between each other and they
may be set in line or in pairs, one pair in front of the other, or at different points on
the boss in the vertical plane.
Dated this 22nd day of November 1888
-
GIOVANNI CUSTANTE, PARINI.
By Cheesbrough & Royston,
Applicant's Agents.
COMPLETE
SPECIFICATION.
Improvements in Screw Propellers for Navigable Vessels.
I, GIOVANNI CUSTANTE PARINI, of 156, Dale Street, Liverpool, in the County of
Lancaster, Restaurateur, do hereby declare the nature of my said 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 relates to screw propellers for Navigable Vessels, and has mainly for
its object to enable the water to pass freely from the propeller blade at the root of the
blade instead of being churned round and disturbed, as is the case with the common
construction of screw propeller.
To the above ends, and according to my Invention, I construct the blades (of which
there may be two or more on the boss, which may be of the usual kind) with a
differential pitch, that is to say, I give the blade a fine pitch at the root and a full or
coarse pitch at the extremity. The blades may be straight or set back, and they may
be set on the boss at their root so as to leave a channel between each other and they
may be set in line or in pairs, one pair being in front of the other, or at different
points on the boss in the vertical plane.
The nature of my Invention will be more fully understood on reference to the
accompanying two sheets of drawings which make a part of this Specification and
which are marked with letters and figures of reference corresponding with those in
the following explanation, like letters and figures being used to denote the same, or
corresponding parts throughout the drawings.

page_text: Figure 3 is a perspective view of a propeller formed according to my Invention.
The main features in a propeller with my Improvements are, that the blades a are
set on the boss b at an uneven or differential pitch which is obtained by setting the
blades a on the boss b so that the blade a at its root is at the same or nearly the same
angle to the horizontal axis of the boss that it is at its extreme end: the blades a are
also thrown or bent over at their ends a¹-as shown in Figure 2-and the leading
edge of the blade a is set back at the root a²-as shown in Figure 3-so as to leave
an easy channel between the blades for the water to pass freely. The blades a may
be set on the boss b in line-as shown in Figure 3-or they may be set in pairs on
the boss one pair in front of the other, or at different points on the boss in the
vertical plane, and the blades may be set on or spring from the boss at any desired
angle to its horizontal axis.
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 :-
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1. The screw propeller for navigable vessels constructed substantially as herein
described and set forth with reference to the drawings.
1000
CHEESBROUGH & ROYSTON,
15, Water Street, Liverpool, Agents for the Applicant.