Improvements in Propellers for Ships or Vessels.
Year: 1889

page_text: Date of Application, 27th Dec., 1889
Complete Specification Left, 24th Sept., 1890-Accepted, 1st Nov., 1890
PROVISIONAL SPECIFICATION.
Improvements in Propellers for Ships or Vessels.
I, RALPH HALL, of 8 Dixon Avenue, Crosshill, in the County of Lanark, North
Britain, Electrical Engineer, do hereby declare the nature of this invention to be as
follows, that is to say :-
My said invention relates to propellers which like ordinary screw propellers consist
in each case of propelling blades fixed on a longitudinal shaft made to rotate by a
steam engine or other motor; and my object is to obtain increased propelling efficiency
by making the blades of an improved form.
In carrying out my invention 1 make a propeller with two or more blades each of
which is a segmental conoidal shell or a segment of a hollow cone.
The shape may vary
to some extent from that of a simple cone; but my improved blade is in form like about
half of a simple cone as divided by a plane passing through the axis, and the blade is
fixed with one slant edge parallel and close to the shaft the other slant edge forming the
entering edge of the blade, the apex and base of the cone being at the forward and
after parts of the propeller respectively. The two or more blades may be cast or
otherwise formed in one piece with a boss which may be fixed on the shaft in the
ordinary way; or each blade may be a separate piece, and it may be bolted to the boss,
the bolts passing through a flange formed for the purpose along the inner edge of the
blade.
Doted this Twenty cirth dow of Danombor 1889
COMPLETE SPECIFICATION.
Improvements in Propellers for Ships or Vessels.
I, RALPH HALL, of 8 Dixon Avenue, Crosshill, in the County of Lanark, North
Britain, Electrical 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, that is to say :—
My said invention relates to propellers which, like ordinary screw propellers, consist
in each case of propelling blades fixed on a longitudinal shaft, made to rotate by a
steam engine or other motor; and my object is to obtain increased propelling efficiency
by making the blades of an improved form.
In carrying out my invention I make a propeller with two or more blades each of
which is a segmental conoidal shell, or a segment of a hollow cone.
The shape may
vary to some extent from that of a simple cone; but my improved blade is in form
like about half of a simple cone as divided by a plane passing through the axis, and
the blade is fixed with one slant edge parallel and close to the shaft or nearly so, the
other slant edge forming the entering edge of the blade, the apex and base of the cone
being at the forward and after parts of the propeller respectively, and the concavity
of each blade facing in the direction of rotation for propelling ahead.
The two or more blades may be cast or otherwise formed in one piece with a boss
which may be fixed on the shaft in the ordinary way; or each blade may be a separate
piece, and it may be bolted to the boss, the bolts passing through the blade near its
inner edge, or through a flange formed for the purpose along the inner edge of the
blade.

page_text: a
And in order that the improved form to be given to the propeller blades, which
form constitutes my invention-may be properly understood I hereunto append
sheet of explanatory drawings upon which a three-bladed propeller is delineated by
way of example.
Figure, 1, is a back elevation"
Figure, 2, is a side elevation, and
Figure, 3, is a front elevation.
In this example the blades, A, are shown as made separately and as bolted on a
boss, B, which is fixed on the shaft, C, in the usual way. The direction for propelling
ahead is indicated by the arrows.
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 :-
--
Making blades of propellers for ships or vessels of the improved form substantially
as hereinbefore described and as shown in the accompanying drawings.
Dated this Twenty-third day of September 1890.
EDMUND HUNT,
Applicant's Agent.