IMPROVE- MENTS IN PROPELLERS
Year: 1883

page_text: LETTERS PATENT to Benjamin Waddy Maughan, of Cheapside, in the City of
London, Gas and Water Engineer, and Samuel Danks Waddy of Finsbury
Park in the County of Middlesex, Gentleman, for an Invention of "IMPROVE-
MENTS IN PROPELLERS
"
PROVISIONAL SPECIFICATION left by the said Benjamin Waddy Maughan
and Samuel Danks Waddy at the Office of the Commissioners of Patents on
the 24th October 1883.
BENJAMIN WADDY MAUGHAN, of Cheapside, in the City of London, Gas and
Water Engineer, and SAMUEL DANKS WADDY, of Finsbury Park, in the County of
Middlesex Gentleman, "IMPROVEMENTS IN PROPELLERS
"
Our invention is designed to facilitate the propulsion of vessels in water or air
and relates chiefly to improvements in propellers of the class described in the
Specification of our former Letters Patent dated 27th September A.D. 1882 No 4585.
One feature of the propellers described in the said Specification consists in con-
structing their blades or wings so that their acting surface is composed of two or
more planes inclined relatively to each other.
According to our present invention we substitute for these inclined planes curved
surfaces so arranged as to act very advantageously for the purpose of our invention.
We make each blade of such a transverse section that its acting surface (that is to
say the surface which in the act of propulsion exerts pressure on the air or water)
consists of two or more convex portions which may be segments of a circle or of an
ellipse or other curved figure. The chords of these segments may be one straight
continuous line or may be more or less inclined to each other; the reverse side of
the blade may be similarly or otherwise curved or straight. We have ascertained
that, whether these blades are constructed with plane surfaces as in the said former
Specification or of convex surfaces according to our present invention the line of
junction of the two surfaces between the root and tip of the blade may be radial or
inclined and either straight, zig-zag, or curved and in some instances the configuration
of the edges of the blade may conform to the curved line of junction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the suid Benjamin Waddy Maughan and Samuel Danka Waddy in the
Patent Office on the 24th April 1884.
BENJAMIN WADDY MAUGHAN, of Cheapside, in the City of London, Gas and
Water Engineer, and SAMUEL DANKS WADDY, of Finsbury Park, in the County of
Middlesex, Gentleman, "IMPROVEMENTS IN PROPELLERS
"
Our invention is designed to facilitate the propulsion of vessels in water or air,
and relates chiefly to improvements in propellers of the class described in the
specification of our former Letters Patent dated 27th September, A.D. 1882, N° 4585.
One feature of the propellers described in the said former specification consists
in constructing their blades or wings so that their acting surface is composed of
two or more planes inclined relatively to each other.
According to our present invention wo substitute for these inclined planes,
convex surfaces so arranged as to act very advantageously for the purpose of our
invention. Wo make each blade of such a transverse section that its acting surface
(that is to say, the surface which, in the act of propulsion, exerts pressure on the
air or water) consists of two or more convex portions which may be segments of a
circle or of an ellipse or other curved figure. The chords of these segments may
form one straight continuous line or may be more or less inclined to each other;
the reverse side of the blade may be similarly or otherwise curved or straight.
Our invention is illustrated in the accompanying drawing, in which
-
Figure 1 is a front elevation of one form of propeller-blade made with convex
portions as above described.
Figure 2 shows transverse sections at different parts of the same, and
Figure 3 is a plan of the said blade.
:
Figures 4 to 7 are transverse sections of propeller-blades showing different forms
of the said convex portions.
The remaining Figures are hereinafter referred to.
a, a are the convex or acting surfaces of the blade. In figures 1 to 3 the
curves of these surfaces are segments of circles and the chords of the said segments
are slightly inclined to each other. In Figure 4 the said chords form one
continuous straight line. In Figure 5 they are inclined to each other in the
reverse manner to those shown in figures 1 to 3.
In Figure 6 the curves are flattened towards the centre of the blade, and in
Figure 7 they are flattened towards the edges of the blade,
We have ascertained that whether these blades are constructed with plane
surfaces, as in the said former specification, or with convex surfaces according to
our present invention, the line of junction of the two surfaces between the root and
tip of the blade may be radial or inclined and either straight, zig-zag, or curved.
Figures 8 to 13 are face views of propeller-blades illustrating this feature of our
invention, and in these figures b represents the said line of junction.
In some instances the configuration of the edges of the blade may conform to
the curved line of junction.
Figure 14 illustrates a curved blade made in accordance with this modification
of our invention
We have described the propeller-blades as made with two convex surfaces or
portions, but they may be made with a larger number of such portions if desired.
It is obvious that the convex surfaces or portions and the line of junction above
described may be of other shapes than those shewn in the drawing.

page_text: Having thus fully described our said invention and the manner of performing
the same we wish it understood that we claim :-
First. A propeller-blade constructed with its acting surface composed of two or
more convex or curved portions, and with a transverse section such as shewn in
either of the Figures 2, 4, 5, 6 or 7, or any other suitable section.
Second. In a propeller, the construction of the blades with two curved or plane
surfaces whose line of junction from the root to the tip of the blade is transversely
inclined as in figures 8 and 9, or zig-zag, or curved as in Figures 10 to 13, or in a
substantially similar manner.
Third. The modification of our invention wherein the contour of the blade is
made conformable to such line of junction, substantially as described with reference
to Figure 14 of the drawing.
Fourth. The modification of our invention wherein the reverse side of the blade
is made with convex or curved portions, substantially as set forth.
In witness whereof I the said Benjamin Waddy Maughan for myself and on
behalf of the suid Samuel Danks Waddy have hereunto set my hand and seal this
Twenty third day of April in the year of Our Lord One thousand eight hundred
and eighty four.
BENJAMIN WADDY MAUGHAN (L.S.)