AN IMPROVED PROPELLER FOR VESSELS
Year: 1883

page_text: LETTERS PATENT to Augustus Figge of Dashwood House, Old Broad Street
in the City of London Civil Engineer for an Invention of AN IMPROVED
PROPELLER FOR VESSELS,
PROVISIONAL SPECIFICATION left by the said Augustus Figge at the Office
of the Commissioners of Patents on the 21st April 1883.
AUGUSTUS FIGGE of Dashwood House Old Broad Street in the City of London
Civil Engineer AN IMPROVED PROPELLER FOR VESSELS
My Invention is for a reversible one-bladed oscillating propeller for vessels
which moves in an arc at right angles to the keel line of the vessel to which it is
applied
The blade of the propeller is of a rudder shape being narrower and thicker
towards the neck where it terminates in a spindle to which is fitted a flange or
collar. The section of the blade is preferably convex on both sides thus making it
thick in the center & tapered off at the edges, but this section may be varied
The propeller has two motions given to it namely, one by the engine by which
it describes an arc round the centre of the driving shaft at right angles to the path
of the vessel alternately from left to right and from right to left. The other
motion is caused by the action of the water on the blade making it during its
course to turn on its own axis about 45 degrees on one side of a line drawn
through its axis parallel to the path of the vessel to about 45 degrees on the other
side of the same line.
This motion is imparted to the propeller in the following manner
The neck of the propeller has two lugs or projections opposite to one another,
the neck is enclosed in a cylindrical case which is fastened to the driving shaft and
has a recess corresponding with the flange or collar fitted to the neck forming a
bearing. The internal bearing surface of this case may be made of a separate part.
On this internal bearing surface are fixed two lugs or projections' which meet those
on the neck so as to allow the propeller a backward and forward play without its
being able to revolve entirely.

page_text: In order to reverse the action of the propeller, I connect either the top of the
spindle, or when the cylindrical case has a separate inner part, the upper portion of
that inner part, to a universal or double joint which joint can be turned by a shaft
or otherwise in any convenient manner By turning this joint the back part of
the propeller can be brought round to the front thus reversing its action without
stopping or reversing the engines
Instead of employing the lugs or projections on the cylindrical case or neck as
above described, I can obtain a similar motion by means of a lug fixed to the
neck, working in a spiral groove or slot in the cylindrical case or vice versa;
but in this case the action of the propeller cannot be so readily reversed as above
described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Augustus Figge in the Great Seal Patent Office on the 20th October
1883.
AUGUSTUS Figge of Dashwood House Old Broad Street in the City of London
Civil Engineer "AN IMPROVED PROPELLER FOR VESSELS"
.
My Invention is for a reversible one bladed oscillating propeller for vessels,
which moves in an arc at right angles to the keel line of the vessel to which it is
applied
:
The blade of the propeller is of a rudder shape being narrower and thicker
towards the neck where it terminates in a spindle
The section of the blade is preferably convex on both sides thus making it thick
towards the axial line and tapered off at the edges, but this section may be
varied. It is essential however that the greater portion of the surface of the
blade should be to one side of the axial line
The propellor has two motions given to it, one by the driving shaft which causes
it to move in an arc round the centre of the driving shaft at right angles to the
path of the vessel alternately from left to right and from right to left describing a
segment of about 90° that is 45° on either side of the keel-line, but it is not
necessary to adhere to this particular segment-It may be varied.
This is done by means of a metal piece attached to the end of the driving shaft
surrounding the neck of the propeller-This metal piece has a circular flange
fitting into a corresponding recess in the neck of the propeller, as shewn in the
drawings after referred to, the propeller being free to rotate on its own axis
The driving shaft of course does not rotate but oscillates from left to right and
from right to left to the given degree
The other motion is caused by the leverage of the water on the propeller blade
making it during its course to turn on its own axis about 45° on one side of a line
drawn through its axis parallel to the path of the vessel to about 45° on the other
side of the same line
To enable the action of the water to impart this motion to the propeller the
following arrangement is carried out :-
To the spindle of the propeller is fitted a flange or collar having two lugs or
projections opposite to one another-This flange or collar is enclosed in a
cylindrical case which is fitted between it and the metal piece attached to the
driving shaft which gives motion to the propeller as above stated, but is free to .
rotate in it
The outer surface of this cylindrical case has a recess corresponding with a
projection on the said metal piece attached to the driving shaft
On the internal surface of the cylindrical case are fixed two lugs or projections
which meet those on the flange or collar fitted to the spindle so as to allow the
propeller a backward and forward play without its being able to revolve entirely-
Instead of the lugs or projections on the inner surface of the cylindrical case I
can make grooves in which the lugs or projections on the collar work or vice versa
I can make the lugs on the inner surface of the cylindrical case and the grooves
on the collar
In order to reverse the action of the propellor I connect the top of the
cylindrical case with a shaft by means of a universal joint-By turning this shaft
the cylindrical case is caused to rotate and thus by means of the projections on
the inner surface pressing against the lugs on the flange or collar fitted to the
spindle, the back part of the propeller can be brought round to the front thus
reversing its action at any angle without stopping or reversing the driving shaft,
°

page_text: In the drawing accompanying this Specification Figure I is a sectional elevation
shewing the propeller and the apparatus for giving it the two motions above
described-A is the driving shaft the axial line of which is shewn by the dotted
lines Y Y-B is the propeller blade terminating in a spindle at B'-The axial
line is shewn by the dotted line X X-D is the metal piece fixed to the end of the
driving shaft for the purpose of giving the oscillating motion to the propeller
being attached to the neck of the propeller by a circular flange fitting into a
corresponding recess in the neck of the propeller as shewn at E E-C is the flange
or collar fixed to the neck of the spindle B₁; CC are the lugs or projections in
this flange or collar-F is the cylindrical case surrounding the spindle B' and the
flange or collar C held in its place by a flange on the metal piece D fitting into a
recess shewn at G G-H is the reversing shaft and I is the universal joint attached
to the cylindrical case F and to the reversing shaft H.
Figure II shews a section of the propeller blade B
Figure III is an enlarged section of the head of the propeller shewing the
spindle B¹ and the flange or collar C with the lugs or projections C¹ C¹
Figure IV is a sectional plan of the spindle B' the flange or collar O with the
lugs CC¹ and the cylindrical case F shewing the projections on its internal
surface F1 Fl
Having now described the nature of my invention and in what manner the same
is carried out I claim a propeller for vessels constructed and worked substantially
in the manner hereinbefore described and shewn in the drawing.
In witness whereof I the said Augustus Figge have hereunto set my hand and
seal this twentieth day of October One thousand eight hundred and eighty three.
A FIGGE (LS)