Field of the Invention

Invention relates to vertical wind tunnels, especially to open vertical wind tunnels. Background of the Invention

The prior art discloses multiple open vertical wind tunnels comprising a frame structure in which a power unit is centrally disposed for providing vertical air flow. The tunnel further comprises a flight platform disposed above the power unit and a safety cushion disposed around the flight platform. Most of the open vertical wind tunnels are adapted for assembly and dismantling, therefore it is necessary to design such a vertical wind tunnel which is not only easy to assemble and dismantle but also very compact for transportation.

United Kingdom patent application publication No. 2 290 484 discloses a mobile skydiving simulator consisting of a wheeled transportable trailer of open box design containing a power unit, an air permeable walk net and with platform decking sections that unfold to form a horizontal floor immediately surrounding the vertical air column produced by the machine. Another United Kingdom patent publication No. 2 288 772 discloses a skydiving simulator designed to be trailer-mounted so as to be readily transportable. A flight platform is mounted on a trailer alongside a fan. Similar design is disclosed in the United States patent application publication No. 7,572, 189.

United States patent application publication No. 5,209,702 discloses a vertical wind tunnel housed in a building specifically designed for this purpose, having a hydraulic drive train consisting of two separate hydraulic motors, and a flight platform.

United States patent application No. 4,700,565 discloses an open vertical wind tunnel comprising a device in the form of a supporting skeleton, which is adapted to be dismantled and transported and designed for set-up on a flat base, said device having a wind duct with a unit for accelerating the air and an associated air flow straightener arranged therein. The floating space is limited by nets for protecting the people floating therein. One net is arranged above the flow straightener and another net is disposed above the device. Summary of the Invention

The aim of the invention is to design an open vertical wind tunnel that is very easy to assemble and dismantle and also very compact for transportation.

It was surprisingly discovered that a use of flexible straps also improves the safety of the vertical wind tunnel. Due to flexibility or elasticity of the straps, the safety cushion supported on the straps is in suspended state. Hence, impacts and shocks made by a fall of a user of the tunnel are transferred not only to a structure of the safety cushion but also to the flexible straps.

Therefore, the following design provides further amortization of fall of user of the tunnel increasing the safety.

The present invention is a vertical wind tunnel comprising a central frame structure, a power unit for generating vertical air flow, a flight platform positioned above the power unit, a safety cushion disposed around the flight platform, a peripheral frame structure spaced around the power unit. The vertical wind tunnel is characterized in that it further comprises suspended floor on which a safety cushion is arranged. The suspended floor is arranged between the central frame structure and the peripheral frame structure. The suspended floor comprises flexible straps as well as cross members arranged between the flexible straps.

The power unit comprises a motor, a propeller and an air flow straightener disposed above the propeller. The power unit may be position just below the flight platform, but in another embodiment the power unit may be position further away and an air flow is guided to the flight platform via air flow channels. The following design is used in a so called wall-to-wall wind tunnels.

In another embodiment, the flexible straps may be connected to a flow straightener which might be positioned above the central frame structure.

In context of the present invention the power unit is considered also to has its own frame structure. For example, the flexible straps connected to the power unit means that the skilled person would know that the same flexile straps might be connected to the power unit or to the frame structure or to the flow straightener.

The flight platform is arranged above the air flow straightener of the power unit. The flight platform is a place where persons or users of the vertical wind tunnel move around and practice free flight in a air flow generated by the power unit.

The safety cushion is disposed around the flight platform as well as around the power unit. The safety cushion itself is a part of the flight platform.

The peripheral frame structure is arranged around the power unit forming a gap between which a safety cushion is positioned on a level of the flight platform.

The vertical wind tunnel construction further comprises the flexible straps extending from the power unit up to the peripheral frame structure. A first end of the flexible strap is attached to the power unit and a second end of the flexible strap is attached to the peripheral frame structure. The flexible straps may be any strap known to the person skilled in the art which have elasticity or resilient properties. Elasticity or resilient properties of these flexible straps may be adjusted according to a necessary suspension properties of the safety mattress. The flexible straps may be in the form of ropes, cable, wires, chains or nets used for lashing or securing of cargo for transportation.

Each flexible strap, at least to one of its ends, comprises a connector for easing assembly and dismantling of the vertical wind tunnel, wherein the connector comprises a tensioning member for tensioning the flexible strap for achieving and maintaining a desired tension. The following tensioning members might be found in a transportation industry for securing of cargo.

In another embodiment, the first end of the flexible strap is attached to the flow straightener of the power unit. Generally, the flexible strap may be attached to any suitable element of the power unit.

In another embodiment, the first end of the flexible strap attached to the power unit or the central frame structure is positioned above or slightly above the second end of the flexible strap attached to the peripheral frame structure. Therefore, the flexible strap is inclined relative to the ground level on which the vertical wind tunnel is positioned. Due to the inclined arrangement the water may be drained from the vertical wind tunnel to the periphery thereof.

The vertical wind tunnel further comprises cross members arranged between the flexible straps connecting each other. Elastic members and cross members are arranged such that they form structure resembling a spider web. The connecting element may be in the form of a strap, a belt or a web. The radials connecting elements are also flexible.

The vertical wind tunnel may further comprise a web disposed between the flexible straps and the cross members. In another embodiment only the web may be arranged between the flexible straps, without using cross members.

The vertical wind tunnel further comprises a sound absorbing walls which are suspended on the flexible straps and arranged around the power unit for absorbing of noise generated by the power unit. The sound absorbing walls may be also installed in the peripheral frame structure for further absorbing of noise generated by the power unit.

Brief Description of the Drawings

Fig. 1 shows an open vertical wind tunnel in an isometric view.

Fig. 2 shows a cross section view of the open vertical wind tunnel.

Fig. 3 shows a cross section view of the open vertical wind tunnel without a safety cushion 6 to illustrate cross members 13.

Detailed Description of the Invention

Figs. 1 to 3 shows an open vertical wind tunnel comprising a power unit 1 for generating vertical air flow 11, in which a user of a tunnel may fly simulating skydiving exercises. The power unit 1 comprises a motor 2, associated propeller 3 and an air flow straightener 4 disposed above the propeller 3. The power unit 1 further comprises a central frame structure 16, on which the motor 2 and the air flow straightener 4 is mounted. The vertical wind tunnel further comprises a peripheral frame structure 7 spaced around the power unit 1 and its frame structure 16. A space or gap 8 is formed between the peripheral frame structure 7 and power unit 1 and its frame structure 16. Flexible straps 12 are stretched between the central frame structure 16 of the power unit 1 and the peripheral frame structure 7 and connected thereof. The flexible straps 12 are stretched on such a level that when a safety cushion 6 is positioned of the flexible straps 12, the safety cushion 6 almost in the same level as the flights platform 5. The safety cushion 6 is supported on the flexible straps 12 creating flexible floor.

Each flexible strap 12 is connected to the power unit 1 and the peripheral frame structure 7 by means of a connector 14. The connectors 14 allow easy assembly and dismantling of the flexible straps 12. The connector 14 comprises a tensioning member (not shown in Figures) for tensioning the flexible strap for achieving and maintaining desired tension of created flexible floor. Created flexible floor of flexible straps 12 further comprises cross member 13 which interconnecting said flexible straps 12.

The vertical wind tunnel further comprises sound absorbing walls 15 suspended on the flexible straps 12 for absorbing of noise generated by the power unit 1.

While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing fro the scope of the invention. Therefore, it is intended that the inventions not be limited to the particular embodiments disclosed herein.