Improved Method for Propelling Ships by Means of Air-propellers.
Year: 1887

page_text: Date of Application, 18th Nov., 1887
Complete Left, 26th Apr., 1888
Complete Accepted. 1st June, 1888
Improved Method for Propelling Ships by Means of
Air-propellers.
I, HENRIC CHRISTIAN VOGT, Engineer of 5 Raadhusstroede, Copenhagen in the
Kingdom of Denmark, do hereby declare the nature of this invention, to be as
follows:-
This invention relates to the propelling of ships by means of air propellers. For
this purpose the air propeller is furnished with 2 or more wings or sails of thin brass
or steel, sheet canvas, or other material united to yards or rigid fore sides, which
radiate from the axis of the propeller. The wing can be made in one piece or of
more pieces or plates united together and overlapping each other; all plates are
secured to the yard; by removing the outermost plate, the wing can be shortened.
The pitch or angle of these wings is adjustable in accordance with the direction of
the wind.
Revolving quickly in the elastic air, a rarifaction is created on the front side of these
wings, and the consequent difference in pressure, constitutes the thrust, which, by
the same engine power, is even higher than for the common screw in unelastic
water. The external appearance of an air propeller is similar to an enlarged screw
propeller.
The axle of an air propeller, from which the wings radiate, is, at each end, supported
on the top of a low mast, or pillar.
The cylinders preferably partly resting on the upper deck, are firmly secured, one
to each of these pillars; if three cylinders for triple expansion one pillar more is
required.
Connecting rods, from ends of piston rods, are directly led to cranks, at each end
of the propeller axis. The piston rods are produced or elongated considerably above
the cylinder covers and guided along the pillars. By this contrivance any undue
length of connecting rod is avoided. The area varies accordingly to the speed, but
is generally about 16 times that of a common screw, corresponding to the same size
of ship.
1
O
1
T
L1007

page_text: I, HENRIC CHRISTIAN VOGT, Engineer, of 4 Aagade Copenhagen in the Kingdom
of Denmark 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 :-
:-
This invention relates to the propelling of ships by means of air propellers. For
the purpose of my invention I mount on the deck of the ship a propeller having an
outer appearance somewhat similar to a water-screw propeller but made lighter and
larger and having two or more blades wings or sails, the area of which increases from
the root to the circumference and the angle and pitch of which can be changed
according to the speed, and to the direction and power of the wind for utilising
that power. The axis of the shaft of the propeller is in the length direction of
the vessel. This propeller is rotated from the engine in any suitable manner.
Instead
of one such propeller I may employ two or more such propellers each by preferenco
driven from a separate engine. In addition to these air-propellers I may mount near
the stern of the vessel a smaller propeller which with its framing can be swivelled
laterally round a pivot for the purpose of increasing the manoeuvring power of the
vessel or for assisting the steering; this propeller would be driven by preference
from a separate engine and would suffice as auxiliary propeller for sailing ships.
And in order that this invention may be more fully understood and readily carried
into effect I shall now describe it with reference to the accompanying drawings of
which Figure 1 is a side view and Figure 2 an end view of a vessel provided with
one air screw for only propelling and another smaller propeller for simultaneously
manoeuvring or assisting in steering. Figure 3 is a side view of a wing of an air
propeller mounted on its framing or supporting pillar drawn to a larger scale.
Figure 4 an end view and Figure 5 a plan of the gearing to change the pitch
and angle. Figure 6 is plan view of a screw blade and Figure 7 a cross section
through the same.
As shewn here the air propeller or screw is furnished with three blades wings or
sails V V, V, of proper curvature and tapering towards the axis. The blades may
suitably be made of thin sheet steel, brass, Muntz metal, phosphor bronze or of strong
canvas or other sheet material, properly stiffened and attached to yards y¹ r₁'; yra;
and y, r, in convenient number. The yards are again secured to masts or stems radiating
from thepropeller axis; the masts are properly supported from the axis by means of
stays. The blade or wing may be made in one piece or of more than one piece or
plates united together and overlapping each other so hat by removing the outermost
plate the wing can be shortened.

page_text: The joints between the yards and the sails should possess some elasticity, so also
the yards and the masts or stems m s, in order to yield somewhat when the zone of
the propeller is shifted by the pitching of the vessel. The pitch of the screw is adjustable
in accordance with the speed of the ship and the direction and power of the wind,
for the purpose of utilising that power. The adjustment of each screw blade is here
shown as effected by means of bevel sector wheels t into which gears the bevel
wheel t. The latter is loose on the propeller shaft a and can be turned by an
endless pendant chain or other suitable gearing. The sector wheels are kept from
turning when not required by means of a stop k or by pawl wheels and spring pawls,
the latter being so arranged as to be detachable from the deck when the pitch is to
be altered. Instead of merely turning the screw blades to a certain angle I may
use the motion of the bevel sector wheels in combination with suitable rope tackle
to increase that angle for the outer yards so as to change the pitch more correctly
when the sails of the blades are made of canvas or the like or made in pieces, as
described.
The shaft a of the air propeller is at each end supported in bearings B on the
top of a low box shaped hollow pillar P by preference made in the form of light
open lattice frame work of steel to offer little resistance to the air and resting on
the properly supported deck D or on the keelsons or other interior parts of the
vessel. They are connected by tie rods T and supported by shrouds or stays. The
shaft a with cranks is rotated from the cylinders C and these may be arranged
tandem fashion and on the double treble or quadruple system in the latter case two
above and two below with piston rod connected at top by a cross head. But I do not
specially claim any arrangement or construction of engine or mode of transmitting
motion therefrom to the air propeller shaft.
The area of the propeller blades varies according to the speed but as an approxi-
mation I would state that I have by actual experiments with a steam launch found
about 14 times that of a common screw propeller corresponding to the same size
vessel and revolving at about the same speed of revolution as a suitable proportion.
The air propeller being rotated quickly in the elastic air, a rarefaction on the front
side of the blades or wings is created and the consequent difference in pressure
constitutes the thrust available for propulsion and which with employment of the same
engine power is quite as high as with the common screw in inelastic water. At the
same time I effect a considerable saving in power and fuel because I do away with
the loss now caused by the common screw in drawing away the supporting water
from the vessel, a loss averaging 40 per cent. of the tow rope resistance at high
speeds. With an air propeller can with great advantage reduce the length and
weight of the vessel bringing it into the best form as regards water resistance and
sea-worthiness. My invention is also of special advantage for navigation of rivers
and canals where steamers heretofore have generally been at a disadvantage.
The air propeller shewn at the stern end of the vessel in Figure 1 is mounted in a
framing which can be swivelled around a vertical axis and thus serves to assist in
manoeuvring or steering the vessel.
My invention and particularly the swivelling propeller at the stern is of especial
advantage as a means for providing auxiliary power to sailing vessels where a steam
boiler is usually found or can be easily fitted for supplying a steam winch and other
gear and which can conveniently supply steam to a small engine for working the air
propeller so as to drive the vessel at a moderate speed or to assist it in or against
a light breeze.
When my revolving sails are only used as auxiliary power for sailing ships no
arrangement for changing the pitch is absolutely necessary and the sails could in this
case simply be attached to masts radiating from the axis.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is,
First. The application and use of air propellers or rotating sails for the propulsion

page_text: and manoeuvring of vessels and as auxiliary for sailing vessels substantially as
set forth.
Second. The application and use of air propellers or rotating sails with adjustable
pitch or angle of incidence for the propulsion of vessels so as to utilise steam and
wind powers at the same time, substantially as set forth.
Third. The construction and arrangement of air propellers shewn and described.
تيمم
1
ப
11080