Improvements in Screw Propellers.
Year: 1890

page_text: Date of Application, 15th Dec., 1890
Complete Specification Left, 15th Sept., 1891-Accepted, 21st Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in Screw Propellers.
I FREDRICK HASELDEN of 38 De Grey Street, Newland, Hull in the County
of York, Engineer, do hereby declare the nature of this invention to be as
follows:-
:-
The object of my invention is to construct a screw propeller with interchangable
blades, which shall be stronger at the base of the blades, than those hitherto made,
and also is more easily manufactured.
In the propellers hitherto made, large flanges are cast at the bottom of the
blades, and corresponding recesses bored in the boss; the casting of this mass of
metal at the base, is found to weaken the casting in the bottom portion of the
blade proper, and such blades are usually found to break in that particular part.
I form my boss with projections to which the blades are bolted, such projections
being of a shape to form a portion of the blade, so that should a blade break, the
boss will still have some propelling power. The blades are therefore much
stronger, as a better casting can be obtained, as there is not such variance in the
thickness of metal, and as no recesses are necessary in the boss, the propeller is
much easier to manufacture.
Dated this Twelfth day of December 1890.
JOHN E. WALSH,
Savile Street, Hull, Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Screw Propellers.
I FREDRICK HASELDEN, of 38 De Grey Street, Newland Hull in the County
of York, 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 :-
The object of my invention is to construct a screw propeller with inter-
changeable blades which shall be stronger at the base of the blades than those
hitherto made, and also is more easily manufactured and repaired.
In the propeller hitherto made, large flanges are cast at the bottom of the blades,
and corresponding recesses bored in the boss, the casting of this mass of nietal at
the base is found to weaken the casting in the bottom portion of the blade proper,
and such blades are usually found to break in this particular part.
I form my boss with projections to which the blades are bolted, such projections
being of a shape to form a portion of the blade, so that should a blade break, the
boss will still have some propelling power.
The blades are therefore much stronger, as a better casting can be obtained, and
there is not such variance in the thickness of metal, the propeller is much easier
to manufacture.
DESCRIPTION OF DRAWINGS.

page_text: or manganese bronze, such projections being of a shape to form a portion of the
blade C, so that should a blade break, the boss will still have some propelling
power.
Within the boss A are suitable recesses D, into which fit or rest corresponding
projections E, upon the bottom of the blade C. I also cast upon one side of the
blade C, a suitable projection or lug F. which fits or bears upon the outward edge
of the projections B. a plate G, fitting against the projection or lug F. on the
blade and the projection B, through which pass suitable bolts and rivets, which
firmly and effectively secure the blades of the propeller to its boss. I also further
secure the blades at the bottom by plates H.
By this construction of propeller the blades are considerably decreased in weight
and area, thereby increasing the speed of the ship, they are less liable to break,
and should one blade become damaged, a new blade is easily and effectively
attached.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
Constructing and attaching the blades of screw propellers to their bosses in the
manner and for the purposes such as shown and described.
Dated this Eleventh day of September 1891
JOHN E. WALSH,
Crossley Street, Halifax, and Savile Street, Hull, Agent for the Applicant.