Improvements in Screw Propellers.
Year: 1891

page_text: Date of Application, 11th June, 1891
Complete Specification Left, 11th Mar., 1892-Accepted, 16th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in Screw Propellers.
I, RICHARD DE VILLAMIL, Major in the Royal Engineers, residing at
Portobello Barracks, Dublin, Ireland, do hereby declare the nature of this invention
to be as follows:-
My invention has reference to screw-propellers and its object is to increase the
flow of water through the centre of a propeller and to obviate the relative vacuum,
at the stern of the ship.
My invention consists in the employment of supplementary blades on the "leading
side" (that is towards the ship) of the ordinary propeller blades and perpendicular
to them. I arrange these supplementary blades spirally round the axis of the
propeller shaft, so that, as the latter rotates, they will draw water from the
periphery towards the centre of the propeller and drive it through near the boss.
The supplementary blades may be of any suitable shape or curve and set to any
spiral; they may be cast with the propeller blade or rivetted, bolted or otherwise
fastened thereto, the invention consisting essentially in the employment of supple-
mentary blades on the leading side of propeller blades and so arranged in a spiral
as to draw water towards the shaft.
Delhi. 114h an of Lu 1201
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Screw Propellers.
I, RICHARD DE VILLAMIL, Major in the Royal Engineers, residing at Portobello
Barracks, Dublin, Ireland, 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 screw propellers and its object is to increase the
flow of water through the centre of a propeller and to obviate the relative vacuum
at the stern of the ship.
My invention consists in the employment of supplementary blades on the "leading
side
(that is towards the ship) of the ordinary propeller blades and perpendicular
to them. I arrange these supplementary blades spirally round the axis of the
propeller shaft, so that, as the latter rotates, they will draw water from the periphery
The
towards the centre of the propeller and drive it through near the boss.
supplementary blades may be of any suitable shape or curve and set to any spiral;
they may be cast with the propeller blade or rivetted, bolted or otherwise fastened
thereto, the invention consisting essentially in the employment of supplementary
blades on the leading side of propeller blades and so arranged in a spiral as to
draw water towards the shaft.
Figure 1 of the accompanying drawings is an elevation of the "leading side,"
and Figure 2 a side elevation of a screw propeller constructed according to my
.invention. aa a are the ordinary propeller blades three of which are shown but
the number is variable. bis the boss to which the blades a a a are fixed.
the supplementary blades cast with or secured to the biades a a a perpendicularly
thereto and spirally with relation to the axis of the propeller shaft; the continuation
of the spiral of which each supplementary blade constitutes a part is indicated by
cc care

page_text: dots. Although I have shown only one supplementary blade e on each blade a
there may be more than one at different distances from the boss b.
It will readily be understood that as the propeller revolves in the direction of
the arrow the supplementary blades owing to their spiral arrangement will draw
the water from the periphery towards the shaft and drive it through near the boss.
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
Constructing screw propellers with spiral supplementary blades on the leading
side of the ordinary blades, substantially as and for the purpose hereinbefore
described.
Dated this 10th day of March 1900
J. C. MEWBURN,
55 & 56, Chancery Lane, London, Chartered Patent Agent.