A New or Improved Rotary Sail for Flying Machines.
Year: 1893

page_text: Date of Application, 26th May, 1893-Accepted, 1st July, 1893
COMPLETE SPECIFICATION.
A New or Improved Rotary Sail for Flying Machines.
I, GEORG WELLNER, Professor in the Technical High School in Brünn in the
Empire of Austria 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 :-
The rotary sail for flying machines which forms the subject of this invention
consists of an axle provided with arms and around them are arranged lifting
surfaces, which are turned at slight angles during the revolution by a fixed
eccentric with eccentric strap and rods.
The rotation of the rotary sail when the axle is in the horizontal position
produces the lifting power for rising and soaring in the air and in addition hereto
under certain circumstances the production of power for driving in a horizontal
direction for the purpose of producing forward motion in the direction of the axle.
Figure 1 of the accompanying drawings is an end view of the rotary sail and
Figure 2 a part longitudinal section.
A is the axis of rotation which is mounted in bearings in the standards C and in
the journals B connected to the said bearings.
The shaft A has keyed thereon or otherwise fixed thereto the arms D forming a
sort of star wheel. Either made in one with or fixedly connected to the journals B
are the eccentric discs E, the eccentric straps I of which each have a rigid rod H
while the others (seven in the present case) have jointed connecting rods G. The
lifting surfaces F, of which there are eight, are arranged drum-fashion around the
axle and have stiffening ribs J each of which has two bolts or studs through which
they are movably connected to the star wheel D and to the eccentric by the rods H
and G.
In consequence of this movable connection with the eccentric, the front edge of
the lifting surfaces (see direction of the arrow in Figure 1) in the uppermost
position (No. 3) is raised or is further from the centre and in the lowest position
(No. 7) is nearer the centre at every revolution while it gradually takes up inter-
mediate positions at other periods, so that in the horizontal positions as shown at
No. 1 to the right and No. 5 to the left, the lifting surfaces come near to the dotted
circle of revolution.
In addition, the ribs J of the lifting surfaces and also the arms D G and H may
be made in the form of a screw so that when revolving they may work to propel in
the direction of the axle in the same way as the propeller of a steam ship works in
the water. If the ribs and arms are not made in this manner then the rotary sail
merely has a lifting but no propelling power.
On the drawing the lifting surfaces are shown of an oval form and partly circular
in section with decreasing thickness from front to back, other forms may however
if considered advisable be utilized such as for instance, right angled, elliptic, egg-
shaped, pointed wing-shaped and the like and other sections employed such as
for instance rectilinear tapering, parabolically curved or with sharper or easier
curves.
With regard to the material of which the lifting surfaces are to be made, a hard
substance with stiff ribs may be used such as for instance wood, tinned iron,
vulcanite and the like or instead thereof flexible elastic and soft material may be
employed such as silk, linen, sail cloth or the like with stiff or flexible ribs.
The number of the arms of the wheels, of the star wheel systems and of the lifting
surfaces depends upon the size of the rotary sail.
Motion is communicated to the axle of the rotary sails from a motor by means of

page_text: cranks K as shewn in Figure 2 or by tooth wheels, pulley wheels, or in any other
well known manner.
The rotary sail mechanism with regard to the connection of the movable surfaces
with the fixed eccentric, slightly resembles Morgan's paddle wheel mechanism for
steamships but the action and arrangement of the lifting surfaces in the rotary sail
is quite different.
With reference to the disposition of the rotary sails for flying machines it should
be observed, that they may either be used singly or two or more close to each other
(and in that case preferably in pairs running in opposite directions) or two, three
or more may be arranged behind each other.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is-
1. A rotary sail for flying machines for the production of lifting power and for
or not for motion in the axial direction, in which the lifting surfaces F with straight
or screw-shaped ribs J are arranged in the form of a drum and moved into such
positions by a fixed eccentric with connecting rods, that at every revolution in the
upper position the front edge of the said lifting surfaces is within the mean circle
of revolution and in the lower position outside of the said circle substantially as
described and shown.
2. The construction of rotary sail as shown on the drawing.
d this 26th day of May 1893.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.