A recreational device for producing the thrill of a series of consecutive free falls, which includes a housing, a shock absorbing cushion throughout the bottom of the housing, an inwardly extending peripheral deck near the top of the housing arranged to provide a launching platform for allowing persons to jump into the housing, and a plurality of horizontal planar non-woven nets of elastic bands arranged at different levels within the housing with each net spanning the whole horizontal cross-section of the housing. The elastic bands are randomly arranged within each individual net so as to leave spans between the bands which are insufficiently small to prevent a person from passing through the nets without bouncing on each consecutive net, the elastic bands having an elasticity sufficient to permit persons to manually space the bands to jump from a higher net of bands to a lower net of bands. Each of the horizontal planar non-woven nets are constituted by from 2 to 4 levels of elastic bands, the levels being closely spaced from each other within an individual net to permit the reinforced bouncing of heavy persons whose weight or height of fall may deflect the upper ones of the band levels in an individual net beyond a permissible tolerance.
In one embodiment the amusement device is a series of trampolines arranged vertically and offset to allow a user, starting at the top to spring serially from the uppermost to lower trampolines. A tram can deliver the user to the top. In another embodiment, a trampoline is described which has a rigid support structure except for a portion which is deflectable when excess force is applied so as to prevent injury to a user.
A mechanism for linearizing an open, vertically directed, high-speed air flow, generated by a propeller rotating about a vertical axis, includes a vertical cylindrical element mounted above and coaxially with the rotating propeller and a plurality of radially oriented vertically planar guide vanes supported at their radially outside ends in such a manner that ambient air can flow radially inward below and above the propeller. For large cross-section air-flows and improved elimination of swirl components from the flow, a second set of shorter radial guide vanes is provided in alternation with the vanes that are connected to the cylindrical element. A net structure is disposed above the guide vane structure for use of the invention in a system for producing a relatively large cross-section linearized flow to enable free-fall simulation exercises by one or more participants, to enable trainers to stand close to the free-falling participants. The preferred form of the net includes two orthogonally interwoven sets of cables each of which is individually tensioned at opposite ends and is entirely free of extraneous constraints, e.g., knots or swages, at cable intersections. This net structure, because of its freedom from extraneous flow impedances at cable intersections allows free passage of the upward air flow and serves to further improve the linearization thereof.
