Improvements in Propellers for Ships and Vessels.
Year: 1894

page_text: Date of Application, 5th Oct., 1894
Complete Specification Left, 25th Jan, 1895-Accepted, 2nd Mar.. 1895
PROVISIONAL SPECIFICATION.
Improvements in Propellers for Ships and Vessels.
We GODFREY MAINWARING HOYLAND and EDWARD ALGERNON HOYLAND
both of 8 and 9 Great St. Helens, in the City of London, Shipowners, do hereby
declare the nature of this invention to be as follows:-
Our improved propeller is of the screw propeller class and consists of blades set
obliquely on to a shaft. These blades are concave on the after or principal
propelling face, this surface being a portion of a cone, an ellipsoid, or a sphere, or
it may be of a domed form, but the inam feature of our invention is that on the
back of the leading or cutting edge of the propeller blade we make a wedge like
rib or thickening upon the reverse side of the cutting edge of the blade following
the curve of the blade This rib or thickening extends around the back of the
blade for a short distance inwards from the cutting edge and then terminates in a
more or less abrupt shoulder, the sun face of the b then, with a suitable curvatuo,
falling down to and merging in that of the reverse side of the blade.
Dated this Fifth day of October 1894.
GODFREY M. HOYLAND.
E. A HOYLAND.
We, GODFREY MAINWARING HOYLAND, and EDWARD ALGLRNON HOYLAND,
both of 8 and 9 Great St. Heleus, in the City of London, Shipowners, do horeby
declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertamed in and by the following
statement:-
Our improved propeller is of the screw propeller class and consists of blades set
at a suitable inclination on to a boss to be fixed upon the propeller shaft. Theso
blades are concave on the after or propelling face, this surface being a portion
of a cone, an ellipsoid, or a sphere, or it may be of a domed form, but the main
feature of om invention is that ou the back of the leading or cutting edge of the
propeller blade we make a wedge like rib on thickening upon the reverse side of
the cutting edge of the blade following the curve of the blade. This rib or
thickening extends around the back of the blade for a short distance inwards
from the cutting edge and then terminates in a more or less abrupt shoulder; the
aun face of the b then, with a suitable curvature, falling down to and merging in
that of the reverse side of the blade.
In order that our invention may be fully understood and readily carried into
effect we will proceed to describe the drawings annexed.

page_text: L
Figure 3 shows in outline the face of one of the blades and the sectional form at
vatious points.
a marks the concavity on the puncipal driving face of the blade, the cutting
edge of the blade; c the wedge like 1b or thickening upon the back or reverse of
the blade, d the shoulder in which the rib, after extending a distance mwards from
the cutting edge, terminates.
The propeller represented by the drawings is four bladed, but this is not an
essential feature, the number of blades may be varied and the dimensions of the
propeller will be such as is best adapted to the ship or vessel to which it is intended
to be fitted.
•
Although we prefer that the blades should be concave on the pimeipal propelling
face as shown in the diawings, nevertheless 11bs such as e may with advantage be
applied to blades which are not so formed.
In some cases we provide more than one rib c on the back or reverse of the
blade; if more than one the ribs un parallel the one to the other and each
terminates in a shoulder das is shewn in the transverse section Figure 4, or the ribs
may have a wavey form as in Figure 5.
The reason which leads us to form propellets in the manuet described is that by
so forming them they are enabled to operate upon the functional wake and to utilise
its propulsive force
Having now particularly described and ascertained the nature of our said inven
tion and in what manner the same is to be performed, we declare that what we
claim is
-
1. The wedge like rib or thickening c at the leading or cutting edge of the
propeller blade and upon the reverse side of the blade as herein described.
2. A propeller blade concave on the after or principal propelling face and having
a wedge like rib or thickening upon the reverse side as hercin described.
Dated this 31st day of December 1894.
GODFREY M. HOYLAND
E A. HOYLAND.