AN IMPROVEMENT in THE CONSTRUCTION OF PROPELLERS +1
Year: 1883

page_text: LETTERS PATENT to Joseph Betteley of 166 Fleet Street in the city of
London Marine Architect for an Invention of AN IMPROVEMENT in THE
CONSTRUCTION OF PROPELLERS
+1
ردا
PROVISIONAL SPECIFICATION left by the said Joseph Betteley at the
Office of the Commissioners of Patents on the 9th June 1883.
JOSEPH BETTELEY of 166 Fleet Street in the city of London Marine Architect
AN IMPROVEMENT IN THE CONSTRUCTION OF PROPELLERS
The object of this invention is a special construction of propeller by which a
large surface lengthwise of the shaft and of small surface in sectional diameter is
produced to act upon or against the water for propulsion purposes with greater
and more efficient action than by the propellers usually constructed.
For the purpose of my invention I make each blade of a length double or more
than its width from the shaft boss to the rim which is preferably of semicircular
shape with the points or tips reaching to or nearly to a line with the boss but at a
distance therefrom
1.
I make my blades preferably of plate metal rivetted or welded to the boss said
boss having flanges for the reception of the plates and rivets. The angle at which
I set my elongated blade or blades is governed by the length of the aperture in
the vessel in which it or them have to be placed. The intention being to obtain
high propulsion in vessels of light draught specially designed for shallow waters

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Betteley in the Great Seal Patent Office on the 7th December
1883.
JOSEPH BETTELEY of 166 Fleet Street in the city of London Marine Architect
AN IMPROVEMENT IN THE CONSTRUCTION OF PROPELLERS
The object of this invention is a special construction of propeller by which a
large surface lengthwise of the shaft and of small surface in sectional diameter is
produced to act upon or against the water for propulsion purposes with greater
and more efficient action than by the propellers usually constructed.
For the purpose of my invention I make each blade of a length, double or more
than its width from the shaft boss to the rim which is preferably of semicircular
shape with the points or tips reaching to or nearly to a line with the boss but a
distance therefrom. I make my blades preferably of plate metal rivetted or
welded to the boss said boss having flanges for the reception of the plates and
rivets. The angle at which I set my blade or blades is governed by the length of
the aperture in the vessel in which it or them have to be placed. The intention
being to obtain high propulsion in vessels of light draught specially designed for
shallow waters or canals.
My invention is clearly shown in the annexed sheet of drawings Figure 1 is
an elevation and Figure 2 an end view of one form of propeller composed of two
distinct blades A, B on the same boss C each blade commences and terminates at
the axial line of the shaft D and projects from the boss C as to make the blade
about double the length from point a to point b to that of the depth from c to d
each blade is one half the diameter of the complete propeller and is a true segment
of a circle according to the pitch at which the blades may be set.
Each blade is of sheet steel or other suitable sheet metal and is rivetted to the
flanges E of the boss C as to be readily fitted in position or removed therefrom.
Figure 3 is an elevation and end view of another form of a pair of half circular
screw blades on the same boss, the front projecting ends bb being somewhat
shorter and with the points more rounded than the half circular screw blades
shown in Figure 1. The ends a a of these half blades work in shaped recesses ef
of the screw aperture of the vessel F but the half blades may be on distinct bosses as
at Figures 4, 5. 6 and 7 and occupy a position one behind the other as to ensure a
large surface lengthwise for propulsion purposes compared to the actual diameter
of the propeller.
In the latter views the half blade propellers with projecting ends a'b are formed
in a pieco with the bosses C, C, and they are mounted on the shaft D one in
advance of the other.
'
Figure 6 shows the two half blades of shorter or closer pitch than those in the
other figures but in all cases the half blades project beyond the ends of their bosses
the screw aperture being necessarilly longer in proportion to its depth and so placed
or arranged in the stern or other suitable part of a vessel as to work in as dense
water as possible to prevent racing of the engines and to ensure the best results
particularly with boats or vessels of light draught or working in canals, lakes,
shallow rivers etc
Having now described the nature of my said invention and in what manner the
same is to be performed I declare that I claim as my improved construction of
propeller for the propulsion of vessels as herein set forth. Making and employing
half blades whose surfaces are greater in length from point to point than in width
from the boss to the periphery of the diameter the ends of said half blades

page_text: projecting beyond the ends of the boss or bosses and with the points in line or
nearly so with the axial line of the shaft substantially as shown in the annexed
drawings
In witness whereof I the said Joseph Betteley have hereunto set my hand and
seal this Seventh day of December in the year of our Lord One thousand eight
hundred and eighty three
Witness
H GARDNER
Patent Agent
166 Fleet Street
London
JOSEPH BETTELEY (L.B.)