~ f iS;8 The invention relates to an apparatus for the artificial production of an air stream for the purpose of suspending persons in air.
It is known to produce an artificial airstream, in a stationary installation, for the purpose of sus-pending persons in air. In such a case, the airstream is circulated in a fully enclosed structure. Since the air is circulated, an installation of this kind must be considerable structural height, requires a considerable investment and is costly to maintain.
One particular disadvantage of an installation of this kind is that the circulated air has to be cooled by means of s~ecial equipment.
It is an object of the present lnvention to provide an apparatus of the type mentioned heretofore, by means of which an artificial airstream, for the purpose of suspending ~ersons in air, can be produced at a considerable lower cost, using less material and taking up less space. More particularly, the apparatus according to the invention enables to dispense with the cooling of the air.
According to the invention, this above object may be achieved by means of a collapsible and transport-able supporting frame which is designed to be set up on a flat base and comprises an air accelerating unit, more particularly a propellor, and a associated flow rectifier. The wind tunnel is preferably in the form of a cylinder or a truncated cone.
According to the invention, a stretched net is arranged above the flow rectifier, while the external parts of the supporting frame are extended upwardly above this net and are partly or wholly surrounded 4~
by a restricting net. This enclosed space serves as the suspension area which, for the sake of sa~ety, is closed off at the top by a roof restricting net.
It is desirable for the latter to comprise a central layer which is impermeable, or almost impermeable, to air. The air stream produced by the propellor im-pinges upon this layer from below, thus causing the said roof net to arch upwardly. In order to ensure that there is adequate room for floating, as compared with the length of the supporting frame below the net, the length of the parts of the said supporting frame extended beyond the net is approximately 1 : 1 to 1 :
In order to provide insulation against noise, the supporting frame may be lined with a noise insulating wall from the flat base to the level of the horizontally stretched net, the said wall comprising one or more nolse insulated air inlet apertures arranged at a level below that of the propellor. In order to prevent the entry of foreign bodies, the said air inlet apertures are preferably covered with a grating or a net. As seen in plan view, the supporting frame may be circular or polygonal, and the whole floor area may be covered with a noise insulating layer.
According to a preferred embodiment of the invention, a peripheral resilient layer is arranged in the form of an annular disc on the same level as the horizontally stretched net, the said disc being preferably in the form of a layer of air cushions divided into individual independent sectors. The design selected for the supporting frame makes it possible to surround it, at no great expense, with a stand for spectators,
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the said stand also providing access Eor persons proceed-ing to the air stream and accommodating a control- and switching cabin. In view of the purposes for which the said stand is intended, it will start approximately at the same level as the horizontally stretched net.
The apparatus according to the invention may easily be erected and dismantled at any desired location. It allows persons to float safely and, at the same time, to be observed. Also the maintenance, erection and dismantling are extremely economical, especially since the necessary cooling of the air is eliminated.
The invention is illustrated in the annexed drawings which represent a preferred embodiment thereof and is described hereinafter in greater detail.
In the drawings:
FIG. 1 is a vertieal seetion through an appa-ratus according to the invention, and FIG. 2 is a horizontal seetion through the same apparatus.
The apparatus according to the invention which is illustrated in the drawings comprises a collap-sible and transportable supporting frame 4 designed to be set up on a flat base 6. As may be gathered from Fig. 2, the vertical supports of frame 4 are ar-ranged in a circle. A cylindrical wind tunnel 1 contain-ing a propellor 2 which produces the air stream is located centrally of the apparatus. The propellor is connected to a drive 8 through a gearbox 16 and a cardan-shaft 17. A flow rectifier 3 is arranged above propellor 2, in the wind tunnel 1. The top
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of the said wind tunnel is closed off with a horizontally stretched net 5 which may be made of steel wire or plastic. There is thus no danger that persons floating in the air stream will slide down into the wind tunnel 1. ,, In order to reduce the noise arising from the propellor 2, supporting frame 4 is lined with a noise insulating wall 7 from the flat base up to the level of the horizontally stretched net 5, the said wall containing a plurality of noise insulated air inlet apertures 8 which are arranged below the level of propellor 2 and are covered externally with gratings or the like.
Above the horizontally extending net 5 there is provided outside the area of the wind tunnel 1 a peripheral layer of air cushions 9. The outer parts of the supporting frame 4 extend upwardly above the net 5 and carry a restricting net 10. The extension of the supporting frame 4 is larger than the supporting frame 4 under the horizontally extending net 5. As an upper closure of the suspension area l9 there is provided a roof restricting net ll which has a central impermeable layer 12. By means of this impermeable layer 12 the roof restricting net 11 will be arched upwardly by means of the air stream generated by the propellor.
It is possible to provide the apparatus with a peripheral stand 13. On this stand there can be provided a seating arrangement 20 for the spectators as well as a control and switching cabin 15 for the equipment. In addition this stand 13 is used as an entry to the suspension area 19. For security purposes 3L2~
as well as for the spectators, and also for the persons suspended in the suspension area the stand 13 for the suspension area 19 is provided with a transparent lining made of Plexiglas TM The stand 13 is covered with a roof 21.