FIELD OF THE INVENTION Invention relates to safety nets for leisure, sport events as well as military training purposes. Said safety net can be installed in sky diving simulators also known as vertical wind tunnels or recirculating vertical wind tunnels.

BACKGROUND OF THE INVENTION

Typical safety net is illustrated in US patent application No. 2013/0005537A1 disclosing a trampoline which includes a frame, a safety net which is hung on the frame by means of springs. From the prior art of sky diving simulators it is known that a base for flying chamber is formed by a safety net. US patent No. 7,832,265 discloses a vertical wind tunnel, which levitates a flyer over a rotating fan. A steel mesh net is placed between the fan and the flyer so that the flyer does not fall into the rotating blades of the fan. In the mean time the steel mesh net works also as base surface for flying arena or chamber. The net is connected with framework by means of ropes forming a connection area. Usually safety nets for vertical wind tunnels are similar to leisure trampolines.

Another US patent No. 6,083, 100 discloses vertical wind tunnel training device cable net and suspension system having springs.

Due to space restrictions vertical wind tunnels use relatively short and stiff springs which is satisfactory for normal use in vertical wind tunnels. However, if during the flying exercise vertical wind tunnel suddenly loses a power, the flyer falls directly onto the stiff metal cable net. Usually it ends up with different kind of injuries. Sometimes flyer can be as much as 10 to 15 m high above the net.

There has been some experiments to make a safety net much safer by installing longer, less stiff springs but it makes vertical wind tunnel or any other attraction much bigger losing its economical attractiveness. Another try especially for the wind tunnels was to improve an emergency supply for rotating fan. Given solution is very complex and expensive and makes a vertical wind tunnel much bigger.

There is a need to find a new ways to improve a safety of vertical wind tunnels without decreasing its performance and increasing its size.

SUMMARY OF THE INVENTION

The above object is achieved according to the invention by the safety net for leisure and sport events comprising a plurality of elastic members forming a net area, a plurality of elastic members, wherein one end of the elastic member is attached to the end of the cable and a second end is attached to a structure member of the safety net. The safety net further comprises a guiding unit, positioned at the edge of the net area. The guiding unit is configured to bend the cables in such a way that a part of each cable is positioned longitudinally to the central axis of the safety net. Preferably, the cable is bent by 90 degrees referring to the horizontal plane of the safety net. Accordingly, the elastic elements are also positioned generally longitudinally to the central axis of the safety net. Given design reduces dimensions of the safety net without sacrifice of performance and safety. If it is necessary the cables can be bent by less than 90 degrees, for example by 45 degrees referring to horizontal plane of the safety net. The angle of bent depends on design of the safety net to be installed in the wind tunnel or any other attraction where the safety net is necessary. The guiding element can be made in different configurations. For example, roller can serve as a guiding element, where cable runs around roller.

The safety net further comprises a suspension attached to the guiding unit allowing said guiding unit to move during the use of the safety net. Said suspension can be added if additional elasticity of the safety net system is necessary.

The safety net further comprises an additional resilient element that with one end is attached to the elastic elements and with other end is attached to the structural member of the safety net. Additionally, the safety net can be provided with an activation unit configured to keep the additional resilient element in a retracted position and to release the additional resilient element in extended position when an activation signal is given.

The activation unit can comprise an extension means for extending said additional resilient element in a controllable manner. Said means give a control of a speed of extension of additional resilient element, therefore a resilient element can be released in a controllable manner. Said extension means can be spring-loaded or arbor reel system, that controls extension of additional resilient element in a predetermined manner. It is also possible to adjust a speed and load of extension means. Said extension means can be installed in the activation unit and connected to the elastic element or to the additional resilient elements. It can also be installed in the structure member of the safety net and connected to the elastic element or to the additional resilient elements as well as to the cable.

The activation unit can be installed to each elastic member or additional resilient element or cable. In other embodiment, the activation element is installed to the set of elastic members or additional resilient element or cable, therefore decreasing the complexity and amount of necessary activation units without compromising performance.

In one embodiment, all cables and their elastic members can form a set, wherein said set is connected to one activation unit and one additional resilient element. Said design decreases a complexity and improves reliability of the system without decreasing the performance and safety of the safety net.

The safety net comprises a control unit for controlling and activation of the activation unit, wherein the control unit triggers the activation unit in case of emergency or in case when a activation signal is received from an operator of the wind tunnel where the safety net is incorporated.

The safety net further comprises a sensor that detects a force applied to and/or a movement of the net area, the elastic member or the additional resilient element, wherein detected values of force or movement can be used to assess a condition of the safety net. The sensor can be installed in different positions according to the needs of design. It can be installed near or on the cable, elastic member or additional resilient member. The sensor can be any sensor which is configured to register a movement or applied force.

Elastic element and auxiliary or additional resilient element can be made from elastic rope, a spring or from any other resilient material capable of elastic elongation according to the pre-set elasticity.

The elastic element attached to the cable is less elastic than the supplementary resilient element attached to the spring and the structural member of the vertical wind tunnel.

Given invention incorporates a method for operating a safety net for a vertical wind tunnel. The method contains activation or triggering of an activation unit, when an activation signal is received. The activation signal is an alarm signal that indicates the sudden loss of power for the vertical wind tunnel, especially the sudden loss of power for the power plant of the vertical wind tunnel. The activation signal can be also an alarm signal that indicates the manual trigger of an alarm switch by an operator of the wind tunnel.

According to the needs of the safety net user above mentioned elements can be added or excluded from the safety net installation. For example, guiding units can be interchanged from rollers to sliders or vice versa. If necessary, only one end of each cable can be provided with guiding unit, elastic element, additional resilient element and activation unit.

The present invention significantly improves the safety of flyers and decreases an unused space in a flying chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 illustrates a principal scheme of a safety net from the prior art installed in a vertical wind tunnel.

Fig. 2 illustrates a principal scheme of a safety net with guiding units 10 and elastic elements 3.

Fig. 3 illustrates a principal scheme of alternate embodiment wherein guiding units 10 are rollers. Fig. 4 illustrates a principal scheme of the safety net, which further comprises additional resilient element 11 and activation unit 12 and the safety net is in armed or retracted position.

Fig. 5 illustrates a principal scheme of the safety net, which further comprises additional resilient element 11 and activation unit 12 and the safety net is in activated or extended position.

Fig. 6 illustrates the safety net installed in vertical wind tunnel.

Fig. 7 illustrates the safety net 1 having elastic element 3 only on one side of a cable 2. Before explaining the disclosed embodiment of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangements shown, since the invention is capable of other embodiments. In addition, the terminology used herein is for the purpose of description and not of limitation. Referring to Figs. 2 - 7, a safety net for leisure and sport events comprising a plurality of cables 2, wherein said cables 2 forming a net area 5, a plurality of elastic elements 3 wherein each elastic elements 3 with a one end is attached to the end of the cable 2 and with a second end is attached to a structure member 4 of the safety net. The safety net further comprises a guiding unit 10, positioned at the edge of the net area 5, configured to bend the cables 2 in such a way that a part of each cable 2 is positioned longitudinally to the central axis X of the safety net. The elastic elements 3 are positioned generally longitudinally to the central axis X of the safety net.

In Fig. 2 and Fig. 6 the guiding unit 10 is a sliding element, about which the cable 2 slides over and turns by generally 90 degrees. In Fig. 3 the guiding unit 10 is a roller system, on which the cable 2 runs and turns by generally 90 degrees.

The safety net 1 optionally can comprise a suspension 13 (shown in Fig. 2) configured to suspend the guiding unit 10 giving additional elasticity to the safety net system.

In Fig. 4 and Fig. 5 the safety net further comprises an additional resilient element 11 with one end attached to the spring 3 and with other end attached to the structural member 4 of the safety net. Additionally, an activation unit 12 is provided and configured to keep the additional resilient element 11 in a retracted position and to release the additional resilient element 11 in extended position when activation signal is given.

Activation unit 12 comprises an extension means, not shown in figures, configured to extend said additional resilient element 11 in a controllable manner. The safety net further comprises a control unit, not shown in figures, for controlling the activation unit 12, wherein the control unit triggers the activation unit 12 in case of emergency.

The safety net further comprises a sensor 20 that detects a force applied to and/or a movement of the net area 5, the elastic member 3 or the additional resilient element 11, wherein detected values of force or movement can be used to assess a condition of the safety net.

In Fig. 6 the safety net 1 is installed in the vertical wind tunnel. The safety net 1 having cables 2 with elastic members 3 that are attached to a structural member 4. The structural member 4 can be any member of a vertical wind tunnel that is capable to withstand predetermined forces. The cables 2 are bent by the guiding unit 10.

Referring to Fig. 7 the safety net 1 has elastic elements 3 attached to the one side of cables 2 not on both sides as in previous embodiments. Given embodiment is useful where it is necessary to reduce the elements of the safety net 1. Additionally, said embodiment can be equipped with said additional resilient elements 11, suspension 13 and other elements mentioned in the invention (not shown in the Fig. 7). The invention has been described with reference to various specific and illustrative embodiments and techniques. However, one skilled in the art will recognize that many variations and modifications may be made while remaining within the scope of the invention as defined in the appended claims.