Improvements in the Art of Aërostation, and Apparatus Employed therefor.
Year: 1895

page_text: Date of Application, 19th Nov., 1895-Accepted, 21st Dec., 1895
COMPLETE SPECIFICATION.
Improvements in the Art of Aërostation, and Apparatus Employed
therefor.
I, JOSEPH HOFMANN of No. 1 Lichterfelderstrasse in the City of Berlin
Prussia, in the Empire of Germany, Counsellor of the Government, 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 :-
My invention relates to an improved method for condensing the atmosphere at
the underside of aeroplanes in starting the same, and to apparatus employed
therefor.
Referring to my former Patent, No. 11941 of 1894, I have found, that a flying
machine, taking its path according to Figures 8 and 9 of the said Patent, can be
This
started only by totally or almost totally exhausting the steam-boiler.
difficulty may, indeed, be overcome by an ample expenditure of carbonic acid,
employed either as an addition to the steam of the boiler, or discharged in separate
jets to carry along the products of combustion, but the said auxiliary use of
carbonic acid, in any case, will considerably complicate the whole system and,
further, increase its dangers, owing to the high pressure of the carbonic acid gas
and the extreme reduction in the thickness of the metal of its receiver, both being
indispensable in practical use for the purpose in question.
On the other hand, it has been found and proved by the experiments of Maxim,
that, by gradually accelerating the speed of the body of an aeroplane on a surface
of land or water, the power required for lifting the machine is finally obtained; in
landing, however, the aëronaut is unable to secure an equal, gradual retardation
in the speed of the machine.
My present invention consists in providing an improved method and means for
starting an aeroplane by a short movement of ascent or descent, either in a
perpendicular or an inclined direction, a movement which may be compared to
that of a bird when starting from its nest or from an elevated position, or from
the ground.
In the accompanying drawings, the aeroplane is assumed, as an example, to
be one of that kind as shown and described with reference to Figures 5 and 5^
of my former Patent No. 7919 of 1894, receiving its forward motion by means of
blasts of steam or air.
I wish it to be distinctly understood, however, that the improvements of my
present invention are equally applicable to aeroplanes receiving motion by means
of any suitable propeller.
It would appear, that, as a simpler means for obtaining, in the start, a con-
densation of the atmosphere below the supporting surfaces of an aeroplane, an
arrangement could be employed, consisting of a steeply inclined railway, or of a
platform carried by supports, jointed in parallelogram, or of a trap in the manner
of a falling door or lift. But all arrangements of this or similar kind would be
objectionable for the reason, that they are stationary and, accordingly, an aëroplane
to be started therefrom, fails to possess the desired inobility.
According to my present invention, aeroplanes are provided with mechanical
means of their own, which, at any time, enable the body of the machine, when

page_text: starting, to condense, by means of a falling or rising motion, the atmosphere
bearing directly below the supporting surfaces, in the same way as is the case
while flying freely, which then is obtained by the speed of the machine.
In carrying out the invention, the machine, according to one modification,
illustrated by Figures 1ª, 1 and 2, rests upon a frame constructed as a jointed
parallelogram carried by wheels. In Figure 1 the full weight of the machine
carried by the supports a bears on the wheels e, resting on the ground. Now, if
motion be imparted to the propeller of the machine, or as assumed in the drawings,
the steam generated in boiler bis blown through the nozzles c, against the surfaces a,
the supports d, which at first keep a position slightly to the right of the centre-
line or dead point, will be turned to the left. When the centre or dead-point line
has been passed, the machine begins to fall, as indicated by Figure 1. The
wheels are relieved in proportion as the pressure of the atmosphere against the
underside of the surfaces a, increases, and if the dimensions of all, the parts are
calculated in suitable proportions, the result may be obtained of so far reducing
the pressure of the wheels e, upon the ground that at the end, the machine, by the
action of its propeller (suitably calculated to carry the same in free flight)
overcomes the frictional resistances of the wheels and rises into the air. The
centre of gravity, in this case, will be indicated by a line approximately equivalent
to that shown in Figure 4 under I.
Figures 3 and 3B illustrate another modification in which the machine is shown
resting upon a frame, consisting of rigid supports d and levers f jointed to the
piston-rod of a steam-cylinder 2.
When it is desired to start the machine, steam is admitted into the cylinder g
from below the piston. In this case, the machine, increasing its pressure on the
ground will be first deformed as much as allowed by the arrangement of its
increasing,
springs, then it begins to rise and while the speed of ascension
E,
the pressure of the wheels e, against the ground becomes correspondingly less.
Now, by calculating the throw of the piston and other dimensions in such a
manner, that the machine will have its highest speed of perpendicular lift at or
will be
about the time, when the reaction of the rigid support on the wheels
reduced to nought, then the machine will leap up from the ground, as indicated by
Figure 3B. According to the height of throw of such leaping motion, and also
to the exact period when the propeller proper of the machine has been thrown into
gear, the centre of gravity of the machine will be indicated by lines approximately
equivalent to that of the lines II and II indicated by Figure 4.
In
The construction of the machine according to the modification illustrated by
Figures 3 and 3B, further allows of starting the same in another manner.
this case the machine, is first adjusted to take the position shown in Figure 3B,
the wheels resting on the ground and carrying the full weight of the machine.
Now, by causing the steam to escape from below the piston of cylinder g, the
machine will perpendicularly fall into the position shown in Figure 3 while at the
same time the wheels are being released, and the path described by the centre of
gravity, in starting, is indicated by the line III, Figure 4.
The mode of starting the machine, as last described, may further be modified, if
a double-acting-cylinder be employed instead of the single-acting one, before
described. In this case the machine, resting upou the ground in the position shown
by Figure 34, may act as a body falling freely, it the wheels, by admitting steam
above the piston, are suddenly attracted towards the machine. In this case the
centre of gravity, in starting, will follow the line IV of Figure 4.
It will be well understood that, instead of employing a single steam-cylinder y,
two or more of them may as well be applied and they may be arranged to act
immediately against the ground, and further, the steam-cylinder or cylinders may
be replaced by a spring-motor or motors, or by the cylinder or cylinders of any
motor acting by an explosive mixture, such as gas and air or by powder, if two or
more cylinders of any such kind are employed, the explosion should be adjusted
as to be simultaneous.

page_text: And instead of connecting the upper and the lower frame of the machine by
joints, the two frames might be connected by sliding or rolling guides, an inclined
plane being, for instance, arranged between the two frames.
All devices of this or similar kind will equally serve as a buffer or cushion in
landing the machine.
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. The method of condensing the atmosphere below the supporting surfaces of
aeroplanes while starting the latter, consisting in allowing the machine to transfer
its weight from its solid support to the atmosphere beneath the supporting surface
by imparting to the machine a short ascending or descending motion in a
perpendicular or inclined direction, substantially as and for the purpose described.
2. A flying-machine or air-ship so constructed that those parts destined to rest
upon or make contact with the ground or other solid support are connected to the
body proper of the machine by joints or sliding or rolling guides, in such a manner,
that by the sole action of the propelling mechanism or means, or of separate
motors, such as steam, gas, air, spring motors or the like, or by the combined action
of both, a reciprocal displacement of the said parts of the frame is obtained,
whereby the solid support is released and the machine enabled to fly by the aid
of its common means of propulsion, substantially as hereinbefore described.
Dated this 18th day of November 1895.
WM. P. THOMPSON & Co.,
Of 6 Lord Street, Liverpool, Agents for the Applicant.