Free fall simulator

A free fall simulator with a flight chamber, a fan system to generate airflow in the flight chamber, and a noise attenuation housing substantially enclosing the fan system.

FIELD OF THE INVENTION

The present invention relates generally to free fall simulators and more specifically to a free fall simulator incorporating an improved noise reduction system and an improved ingress and egress system.

BACKGROUND OF THE INVENTION

A free fall simulator is essentially a vertical wind tunnel in which an upward flow or column of air is generated with sufficient velocity to produce a dynamic pressure high enough to suspend a person against the force of gravity. This enables the user to experience all the effects of free fall in a controlled, safe environment. Accordingly, with a free fall simulator, a user can experience the aerodynamic forces and the effects of body movements during free fall without jumping from an aircraft. Free fall simulators have become more popular in recent years because of the significant benefits and cost savings associated with free fall training in a free fall simulator compared to conventional free fall training from an aircraft, and because of the desire of the general public to experience free fall without the dangers and risks associated with jumping from an aircraft. Accordingly, in addition to military and other sky diving training facilities, free fall simulators are being considered for recreation purposes at fairs, carnivals, or the like where they can be used by the general public for experiencing free fall.

A variety of free fall simulators are known in the prior art. Specifically, a free fall simulator installed at Ft. Bragg, North Carolina for the U.S. Army comprises a recirculating system in which a single fan above the flight chamber creates a vertical air stream in the flight chamber sufficient to support a user under free fall conditions. Air which passes through the flight chamber is then recirculated to the bottom of the flight chamber for reuse.

U.S. Pat. No. 5,209,702 issued to Rarenas discloses a free fall simulator with a single fan below the flight chamber for producing a stream of air in the flight chamber to support the user.

The Kitchen et al. U.S. Pat. No. 5,655,909 discloses a sky diving simulator in which a plurality of radially positioned fans at the bottom of the simulator provide the stream of air within the flight chamber sufficient to support the user.

The Jean St-Germain U.S. Pat. No. 4,457,509 also provides a single fan at the bottom of the flight chamber but with a recirculating feature in which the air stream, after passing through the flight chamber, is recirculated back to the fan.

The Macangus et al. U.S. Pat. No. 4,578,037 discloses a sky diving simulator in which three inlet fans are provided at the bottom of the simulator and thus below the flight chamber. These fans are positioned at the end of inclined ducts so that the air inlet flows at an inclined angle from the inlet to the bottom of the flight chamber.

The Kitchen et al. U.S. Pat. No. 5,083,110 discloses a vertical wind tunnel training device providing a plurality of fans positioned above the flight chamber for producing a vertical stream of air within the flight chamber. Kitchen also discloses a single fan at the lower end of the device for producing the vertical air stream in a recirculating structure.

Most if not all of the prior art free fall or sky diving simulators are effective for producing a vertical stream of air with sufficient velocity to support a user against the force of gravity. Few, however, have focused on noise reduction. In any free fall or sky diving simulator, significant noise is generated by the fan drive system, by the movement of air through the fan system, and by jet noise generated by the vertical air stream. These noise sources generate broad spectrum noise that can, without careful design considerations, have damaging effects on both human safety and the structural integrity of the simulator. Noise reduction or noise attenuation has become and is becoming of greater importance as free fall and sky diving simulators, which at one time were found primarily at military installations and more remote locations as training facilities for paratroopers, firefighters, sky divers, etc., are now being installed in more populated areas at or near shopping malls, amusement parks and the like for recreational use.

Accordingly, there is a need in the art to provide a free fall or sky diving simulator which provides improved noise attenuation.

A need also exists in the art for a free fall or sky diving simulator which provides an improved ingress/egress system which permits users to enter and exit the flight chamber or an area adjacent to the flight chamber while maintaining adequate air flow and pressure within the flight chamber to support a user against the force of gravity. Conventionally, ingress/egress openings in the flight chamber or in an area adjacent to the flight chamber are provided with a single air lock door which is closed in substantially sealed, air tight condition while the flight chamber is in use and which is designed and intended to be opened only when the air flow in the flight chamber has been reduced. Thus, users entering or exiting from the flight chamber or an area adjacent to the flight chamber are usually required to do so only when the flight chamber is not in use.

With these conventional designs, the fan speed for the flight chamber, and thus the air flow in the flight chamber, is normally reduced when the air lock door is open to allow users to enter or exit the flight chamber or areas adjacent to the flight chamber. Then, after the air lock door has been closed and sealed, the fan speed is increased to provide the necessary air flow to support a user against the force of gravity.

This repeated reduction and increase in the fan speed to allow users to enter or exit the flight chamber or adjacent areas not only results in increased wear and tear on the fan and other components of the system, but results in significant downtime since the system must be at least partially shut down to allow the users to enter and exit through the opened air lock door.

Accordingly, there is a need in the art to provide an improved ingress/egress system by which users can enter or exit from the flight chamber or areas adjacent to the flight chamber continuously, without decreasing the fan speed or significantly altering the use of the flight chamber.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a free fall or sky diving simulator with fan means for producing a vertical stream of air in a flight chamber to support a user in a free fall environment. The present invention also includes a noise reduction or noise attenuation system associated with the simulator which significantly reduces the operational noise when the system is in use and an improved ingress/egress system.

In a preferred embodiment, the simulator includes a flight chamber and a fan means for producing a vertical stream of air in the flight chamber. Preferably, the fan means comprises a plurality of radially extending inlet air ducts below the flight chamber. Each of these ducts is provided with a fan at its outer end. The noise attenuation means in the preferred embodiment includes a noise attenuation housing at the base of the simulator. The noise attenuation housing includes a canopy positioned above and substantially covering the plurality of radially extending air inlet ducts, a plurality of noise attenuation stacks positioned circumferentially at the outer edges of the canopy and wall portions joined with the outer circumferential edges of the canopy and extending between adjacent stacks to substantially enclose the fan means and air inlet system. In the preferred embodiment, each of the noise attenuation stacks is provided with air inlet means or openings at the upper end of the stack and at a position above the level of the air inlet ducts. These air inlet openings are preferably provided at the upper end surface of the stack itself so that the incoming air enters the stack vertically. The openings, if desired, can be provided with noise attenuation baffles.

In a further embodiment of the present invention, one or more of the noise attenuation stacks can be in communication with the air outlet stream above the flight chamber to provide a recirculating or a closed circuit system.

In a still further embodiment, a closed circuit system is provided with selectively controllable exhaust louvers or openings in the return air stream.

In a still further embodiment, a free fall or sky diving simulator is provided in which the air inlet fan means are provided underground or below grade. In this embodiment, the canopy is or may be at approximately ground or grade level and the vertical noise attenuation stacks would be at or above ground level.

A further feature of the present invention includes an improved ingress/egress system which permits entrance into and exit from the flight chamber or an area adjacent to the flight chamber without decreasing the fan speed and without significantly adversely affecting the air flow or dynamic pressure in the flight chamber. In an embodiment of the invention exhibiting this feature, an area adjacent to the flight chamber is provided with a revolving air lock door, a pair of air lock doors or another substantially air lock door system which substantially limits or precludes air flow or pressure loss from the flight chamber while users are entering or exiting from the flight chamber or areas adjacent to the flight chamber.

Accordingly, it is an object of the present invention to provide a free fall or sky diving simulator with improved noise attenuation means with improved noise attenuation means.

Another object of the present invention is to provide a free fall or sky diving simulator having a substantially fully enclosed noise attenuation system.

A further object of the present invention is to provide a noise attenuation system for a free fall or sky diving simulator having a canopy, a plurality of vertically extending noise attenuation stacks and wall sections joining the canopy and adjacent noise attenuation stacks.

A further object of the present invention is to provide an ingress/egress system by which users can enter or exit from the flight chamber or preparation or areas adjacent to the flight chamber without significantly adversely affecting the air flow and dynamic pressure within the flight chamber.

A still further object of the present invention is to provide a free fall or sky diving simulator in which an area adjacent to the flight chamber is provided with a revolving lock door, a pair of air lock doors, or another air lock door system by which a user can enter or exit the system without a significant loss in dynamic air pressure within the flight chamber.

These and other objects of the present invention will become apparent with reference to the drawings, the description of the preferred embodiment and the appended claims.

DETAILED DESCRIPTION

The present invention relates to a free fall or sky diving simulator which hereinafter, unless otherwise specified, will be referred to as a “free fall simulator”.

General reference is made toFIGS. 1–4which disclose various embodiments of a free fall simulator in accordance with the present invention. The free fall simulator in each of the embodiments ofFIGS. 1–4includes a fan means10(FIGS. 3 and 4) for generating a vertical air stream or air column in a flight chamber11. The air stream generated in the flight chamber11is designed to be of sufficient velocity to produce a dynamic pressure in the chamber that is high enough to support a user entering the flight chamber in a free fall environment. In other words, the velocity of the air stream within the flight chamber11is sufficient to support the user against the force of gravity. The flight chamber11may be of any size or diametrical dimension to support a single user or multiple users. A vertical chamber or column12is connected with and provided above the flight chamber11. The diametrical dimension of the chamber12at its base approximates the diametrical dimension (and thus the cross-sectional area) of the flight chamber11and increases as it extends upwardly.

The free fall simulator of the present invention is also provided with a noise attenuation means in the form of a noise attenuation housing which fully or substantially fully encloses the fan means10below the flight chamber11. In the preferred embodiment, the noise attenuation housing includes a canopy14, a plurality of noise attenuation stacks15positioned circumferentially at the outer edges of the canopy14and a plurality of wall sections16joined with the outer edges of the canopy14and positioned between adjacent stacks15to fully enclose or substantially fully enclose the fan means10.

In accordance with the present invention, the fan means10is comprised of a plurality of air intake members comprising a plurality of generally horizontal air intake ducts18. Each of these air intake ducts18has an inner end in communication with a central air intake chamber19(FIG. 4) and an open outer end20. As shown best inFIGS. 3 and 4, these ducts18extend radially outwardly from the central chamber19.

A fan member21is provided near the outer end of each of the intake ducts18for the purpose of drawing air in through the open outer ends of the ducts20. Each of the fans is driven by a motor. The particular size and type of motor and the particular size, orientation and configuration of the fan blades are selected so that the fan members for all of the intake ducts collectively provide sufficient air flow within the flight chamber11to support the user or users. Proper selection of fan means for this purpose is known in the art. In general, the fans21should be sufficient to provide an air stream in the flight chamber11of approximately 120 to 160 miles per hour.

Any number of air intake ducts18can be provided for the free fall simulator in accordance with the present invention. Preferably, however, the simulator is provided with a plurality (two or more) of such ducts. As shown inFIGS. 3 and 4, the outer ends of each of the air intake ducts18are provided with appropriate support members22.

The flight chamber11is shown in each ofFIGS. 1–5. The flight chamber11includes a plurality of vertical wall struts24, a plurality of horizontal braces25and a plurality of windows26or solid panels28. The specific structure of the flight chamber11can be of conventional design known to those skilled in the art, provided it is sufficient to define an enclosed central area29(FIG. 4).

As shown best inFIG. 4, the flight chamber11is provided directly above, and is in communication with, the central air intake chamber19. In the preferred embodiment, a flow straightener30is provided between the chamber19and the flight chamber11. The flow straightener30conditions the air entering the flight chamber11by reducing its turbulence and providing substantially laminar flow within the chamber11. A safety net31or the like is provided at the bottom or near the lower end of the chamber11between the chamber11and the flow straightener30. The flow straightener30may be of any structure known in the art, but preferably is a honeycomb-type structure.

If desired, the free fall simulator structure of the present invention may be provided with a plurality of auxiliary rooms or facilities32for use as a control room, an entrance/exit area for users to enter and exit the flight chamber11, a preparation room and/or a viewing chamber. The system for entering and exiting the flight chamber will be more fully discussed below with respect toFIGS. 11–17

As shown best inFIG. 3, the flight chamber11and the entire central portion of the free fall simulator is supported by a base34with a plurality of support legs35. The flight chamber11is also preferably provided with a plurality of angled struts or braces36as shown inFIG. 1. These struts or braces36extend from the top of the canopy14to points near the upper end of the flight chamber11. The vertical column12is preferably supported by a plurality of wires or cables38extending between a portion of the column12and the noise attenuation stacks15.

The noise attenuation means of the free fall simulator of the present invention includes the canopy14, the plurality of stacks15and the wall sections16. The noise attenuation canopy14is positioned above the fan means10and below the flight chamber11and extends radially outwardly from near the base of the flight chamber11as shown. The canopy14can be constructed of a single, monolithic structure or can be constructed of a plurality of panels which are connected to one another. The canopy14is preferably substantially horizontally disposed, although it can be positioned at an angle or slope downwardly toward its outer edge if desired. The canopy is preferably constructed of reinforced concrete or any other material which has noise attenuation capability and is sufficient to support the contemplated user traffic to and from the flight chamber11and the auxiliary rooms32

The outer peripheral or circumferential edge of the canopy14is joined with a plurality of noise attenuation stacks15. Any number of stacks15may be provided. For example, inFIG. 1, six such stacks15are provided, inFIG. 2, four such stacks15are provided and inFIG. 3, eight such stacks15are provided. Although it is preferred that the number of stacks15conform to, and be the same as, the number of air inlet ducts18and fan members21, this does not necessarily need to be the case. For example, the number of stacks15can exceed the number of air inlet ducts18or may be less than the number of air inlet ducts18. As shown, each of the stacks15has a lower end39which is supported on a surface substantially the same as the surface upon which the air duct supports22are supported and an upper end40which extends above the canopy14. Each stack15also includes an inner wall41, an outer wall42and a pair of side walls44. Preferably, the amount of each stack15which extends above the canopy14should be at least about 10%, more preferably at least about 30%, and most preferably at least about 60% of the distance between the canopy and the bottom39of the stack15. In the most preferred embodiment as shown inFIGS. 1–4, the stack15extends above the canopy14at least the same distance as it extends below the canopy14.

As shown best inFIGS. 6–8, each of the stacks15is provided with an air intake opening45on the portion of the inner wall41below the canopy14. This opening41is connected with the interior47of the stack15which in turn is in communication with the inlet openings or noise attenuation baffles46. In the preferred embodiment, the noise attenuation baffles46are shown as provided on the top surface of the stack15.

These baffles46are generally elongated openings in the upper end of the stacks15. Preferably the baffles46extend radially from the flight chamber axis and generally parallel to the axes of the inlet ducts as shown in theFIGS. 1,2and3; however, they may extend laterally or at any other angle relative to the inlet ducts. The baffles46may be of any size that attenuates the noise level to the extent desired. As viewed from the top of a stack15, the stack dimensions will vary depending on the airflow needed in the flight chamber, and the number of air inlet ducts18or stacks15. The openings for the baffles will vary in size to meet the noise attenuation and pressure drop requirements. The width of the baffles may vary from several inches to a foot or more and the length and the depth of the baffles may vary from several inches to several feet or more. In some embodiments, the baffles46may be eliminated. In such a structure, the stacks15have a substantially open top. Preferably at least 50% of the stack top is provided with baffles46or open areas.

Accordingly, the number of noise attenuation stacks15, the sizes of the openings48(FIGS. 6–8) and the sizes, numbers and orientation of the noise attenuation baffles46are selected so that sufficient intake air is provided and sufficient noise attenuation is achieved through the baffles46and through the openings48of the stacks15collectively to support the air stream within the flight chamber11.

Like the canopy14, the stacks15can be constructed of reinforced concrete or any other noise attenuation material. The material must also be structurally sufficient to accommodate the stresses imposed by the air moving through the baffles46and the interior of the stacks15.

As shown best inFIGS. 1 and 6, a plurality of walls or wall portions16are provided to substantially enclose the fan means10and in particular that portion of the free fall simulator below the flight chamber11and the canopy14. As shown, these wall sections16join along their upper edges with the outer circumferential edge of the canopy14and along their side edges with the side walls44of adjacent noise attenuation stacks15. These wall sections16, like the canopy14and the stacks15, may be constructed of a variety of materials such as reinforced concrete or any other noise attenuation material. If desired, one or more of the wall sections16may be provided with a door or other entrance/exit means51as shown inFIG. 1.

In one embodiment of the free fall simulator in accordance with the present invention, as shown inFIGS. 1,2and3, the simulator and the stacks15are supported at approximately ground level. In such embodiment, the wall sections16extend above the ground as shown. It is contemplated, however, that with the structure of the present invention, the free fall simulator and the stacks15can be supported below ground level as shown inFIG. 4. In such embodiment, the wall sections16would be positioned below the ground level and the canopy14would be approximately at or slightly above or below ground level. In the embodiment ofFIG. 4, as shown, the upper ends40of the stacks15would extend above the ground level and the intake air ducts18would be supported either wholly or partially below ground level. In the embodiment ofFIGS. 1,2and3, a stairway50or other means may be provided to enable the user to access the top surface of the canopy14for entry to or exit from the flight chamber11.

Although an embodiment in which a canopy14and wall sections16are provided is preferred, one or both of these elements could be eliminated. For example, some noise attenuation can be achieved by connecting the outer ends20of the inlet ducts18to the openings48in the stacks15. In this embodiment, the simulator would be provided with a plurality of air inlet ducts18and a plurality of noise attenuation stacks15connected thereto. Each of the stacks15is provided with air inlet openings in the form of baffles46or an open top.

FIGS. 9 and 10show isometric and sectional views, respectively, of a recirculating or closed circuit free fall simulator. Whereas the free fall simulator embodiments shown inFIGS. 1–4are open systems in which incoming air enters the flight chamber11through the noise attenuation stacks15and exhaust air leaves the system through the upper end of the column12, a recirculating or closed system includes an air recirculating structure in which some or all of the exhaust air can be recirculated and rerouted through the flight chamber

Specifically, the closed system in accordance with the present invention includes many of the same elements and features of the open circuit simulator shown and described with respect toFIGS. 1–4. For example, the closed circuit simulator ofFIGS. 9 and 10includes a flight chamber11, a vertical chamber or column12and a plurality of fan means18for providing sufficient air flow in the flight chamber11to support a user. The closed circuit configuration ofFIGS. 9 and 10also preferably include noise attenuation means in the form of the canopy14, the plurality of noise attenuation stacks15with noise attenuation baffles or openings46at their upper ends and a plurality of wall sections16(FIG. 9) joined with the outer peripheral edge of the canopy14and adjacent noise attenuation stacks15.

Additionally, the closed circuit embodiment ofFIGS. 9 and 10further include one or more substantially vertical recirculation columns or chambers55and a recirculation hood56. As shown, the recirculation hood56comprises a substantially closed chamber above the exhaust column12and is defined by an inner or lower wall60and an outer or upper wall61. The hood56is in communication with the open top of the column12as well as the upper ends of each of the recirculation columns55. The lower or bottom ends of the recirculation columns55are in communication with the noise attenuation stacks15. With this structure, exhaust air from the flight chamber11and the column12can be directed back to the inlet fans18and thus the flight chamber11via the hood56, the recirculation columns55and the stacks15. To reduce turbulence, the juncture between the hood56and the recirculating columns55may be provided with turning vanes59if desired.

The top or outer wall61of the hood56is also preferably provided with a plurality of louvers or outlet dampers58which are capable of being moved between a closed position to preclude air flow through the louvers58, a fully open position in which air can freely flow through the louvers58and any position between a fully closed and fully open position. The louvers or dampers58can be of any conventional structure for controlling the movement of air therethrough.

When the louvers58are fully closed, all or substantially all of the air which exits from the top of the column12is recycled back through the recirculating columns55into the upper ends of the stacks15and in through the fans18for recirculation through the flight chamber11. To the extent the louvers58are open, a portion of the exhaust air is allowed to escape through the louvers58. In this case, only a portion of the exhaust air is recycled through the recirculation columns55. In that event, the makeup or additional air needed for flow through the flight chamber11is drawn in through the open portion of the stack15through the baffles46.

One problem or issue which commonly is encountered with recirculating or closed circuit systems is the buildup of the air temperature in the flight chamber11. Because of heat generated from the friction of the recirculating air and the operation of the fan means18, the air temperature within the system will rise during operation. Depending upon the ambient outside temperature, the air temperature in the flight chamber11can rise to the point where it is undesirably warm. Thus, although a recirculating or closed system assists in heating the air in a flight chamber in northern climates or other areas where the outside temperature is lower than desired, a fully closed system will ultimately cause the temperature within the flight chamber to be too warm.

With the louvers58in the wall61of the hood56, the amount of recirculating air can be controlled. Thus, the temperature of the air within the flight chamber11can be controlled. In accordance with the present invention, this is accomplished by controlling the amount of recirculating air (make up air) and thus the amount of ambient temperature which passes through the flight chamber11.

Associated with the louvers58is a temperature control mechanism which includes a temperature probe62located in the flight chamber, an open/close mechanism64connected with the louvers58, a control box65with appropriate control circuitry and leads66and68. The lead66provides flight chamber temperature information from the temperature probe62to the control65and the lead68provides open/closure signals from the control65to the mechanism64. With such a system, the amount of recirculation air, and thus the amount of make up air, can be controlled. This in turn controls the temperature of the air within the flight chamber11.

Reference is next made toFIGS. 11–17disclosing various ingress/egress systems for entering and exiting the flight chamber.FIGS. 11,12and13show an ingress/egress system which includes a pair of revolving doors70,70on opposite sides of the flight chamber11. These revolving doors70,70are air lock revolving doors which include a plurality of vanes or door panels72having one side edge rotating around a center rotation point75and an outer side edge engaging a seal surface of the curved wall portion74during at least a portion of the revolution of the panels72. In a preferred embodiment, the wall portion74has a circular configuration with a radial center at the point75and the outer side edges of the rotating vanes72are provided with elongated seal members to create a substantially sealing engagement with the wall portion74during revolution. Preferably, the top and bottom edges of the rotating vanes or door panels72are also provided with seal members for correspondingly engaging a floor surface portion and a ceiling surface portion in substantially sealing relationship. The distance between the outer edges of adjacent vanes72and the lateral dimension of the wall portion74are such that during revolution of the door70, at least one of the vanes is always in sealing relationship with the wall portion74. This results in the formation of a transition chamber73between the wall portion74and adjacent vanes72as the door revolves. This transition chamber73enables a sufficient dynamic pressure and air flow within the flight to be maintained while users are entering or exiting from the flight chamber11or an area adjacent thereto.

In the embodiment ofFIGS. 11–13, a short entrance area71is provided between each of the revolving doors70,70and the flight chamber11. In the embodiment ofFIGS. 11–13, the entrance areas71,71communicate with the flight chamber11through openings76(without doors) which communicate directly with the flight chamber11. The areas71,71shown inFIGS. 11–13are only large enough to allow a user to exit from the revolving doors70,70and enter the flight chamber11. If desired, however, the areas71,71can be expanded to accommodate several users, including instructors or the like and can extend circumferentially around a portion of the flight chamber11. It is also possible to extend the areas71,71circumferentially so that they are joined to one another.

A short entrance way or threshold78is provided adjacent the outer end of each of the revolving doors70,70to provide a passage for the user to enter and exit the revolving doors70,70.

The embodiment ofFIGS. 11–13shows revolving doors70,70with four extending vanes or door panels72. However, any number of vanes or door panels may be utilized as long as they maintain the doors70,70in a substantially sealed relationship between the flight chamber11and atmospheric pressure during revolution. Accordingly, the revolving doors70,70require at least two vanes.

Further, although the openings76,76between the areas71,71and the flight chamber11are shown as being open (without doors), doors can be provided, if desired as shown inFIG. 14and as described below. Still further, although the doors70,70are shown inFIGS. 11–13as being exactly opposite to one another, they can be provided at any one of a variety of positions such as that shown inFIG. 14in which the doors are angularly spaced about 90° from one another.

With reference toFIG. 14, a pair of revolving air lock doors70,70are provided at approximately 90° relative to one another. Similar to the embodiment ofFIGS. 11–13, an entrance area71,71is provided between the doors70,70and the flight chamber11to allow the user to exit the revolving door70and enter the flight chamber11or exit the flight chamber11and enter the revolving door70. Unlike the embodiment ofFIGS. 11–13, the embodiment ofFIG. 14includes a door79between each of the entrance areas71,71and the flight chamber11. In the preferred embodiment, these doors79comprise a pair of swinging door panels which preferably swing outwardly, away from the flight chamber11. Thus, for a user to enter the flight chamber from the entrance area71,71, the doors are pulled outwardly toward the user before the user enters the flight chamber11. When exiting the flight chamber11, the user merely pushes the swinging doors79open.

In the embodiment ofFIG. 14, a control room80is provided between the entrance areas71,71. However, if the control room80includes an air lock door83so that the control room is substantially air tight, the areas71,71can be joined with and open to the room80.

FIG. 15is an isometric view showing the entirety of a free fall simulator utilizing the ingress/egress system shown inFIG. 13with the pair of revolving doors70,70and the flight chamber11.

FIG. 16is an isometric view of the free fall simulator shown inFIG. 14, except from a different viewpoint, showing one of the revolving doors70and the flight chamber11.

FIG. 17is an isometric view of a partially recirculating or closed circuit system utilizing a pair of revolving doors70,70as the ingress/egress means for the flight chamber11. Similar to the embodiment ofFIG. 10, this system includes a top or outer wall61and a plurality of vertical chambers55for recirculating at least a portion of the flight chamber air. As shown and described above with respect toFIG. 10, the top wall61includes a plurality of louvers or outlet dampers58for controlling the extent to which air exiting the flight chamber11is recirculated through the columns55.

Although the preferred ingress/egress system in accordance with the present invention includes an air lock door system in the form of a revolving door as shown inFIGS. 11–17, it is contemplated that other air lock door systems could also be used without deviating from the concept of the invention, namely, allowing ingress and egress from the flight chamber and surrounding adjacent areas without reducing, or without the necessity of reducing, the flight chamber fan speed.

For example, an alternate air lock door system could include a pair of air lock doors defining a transition chamber between them. The pair of doors would include an outer door adjacent to the ambient atmosphere and an inner door adjacent to the flight chamber or an area adjacent to the flight chamber. Such pair of air lock doors could be hinged, could be unhinged or could be elevator-type doors, among others. To enter the flight chamber or the surrounding area with this type of door system, one of the doors (the outer door) is opened and the users enter the transition chamber. After the outer door is closed, the inner door is opened to permit the users to enter the area surrounding the flight chamber or the flight chamber directly. The inner door may then be closed. To exit the flight chamber, or the area surrounding the flight chamber, the inner door is opened and the users enter the transition chamber. The inner door is then closed and the outer door is opened to allow the users to exit the transition chamber. Accordingly, with such a system, as well as the revolving door system described above and various other air lock door systems, the flight chamber can remain operational while users continue to enter and exit the system.

Having described the structural aspects of the ingress/egress system in accordance with the invention, the method or operational features of the invention can be described as follows.

First, a flight chamber is provided with sufficient air flow and dynamic pressure to support a user in the air flow stream against the force of gravity. Second, an air lock door system or ingress/egress system is provided which enables a user to enter or exit from the flight chamber or the surrounding area without significantly adversely affecting the air flow or dynamic pressure within the flight chamber. Such a system includes a transition zone or chamber between the flight chamber and the outside atmosphere. This transition zone or chamber may be formed by one or more revolving doors, a pair of doors accessible to the transition chamber or any one of a variety of other air lock door systems.

Third, the air flow generating means is activated to provide sufficient air flow to support a user against the force of gravity and fourth, such air flow is maintained at a level sufficient to support a user against the force of gravity during the ingress and egress of other users from the flight chamber or from the area surrounding the flight chamber.

FIG. 18is a plan view of a flight chamber configuration with an airlock ingress door in the form of the revolving door86and an airlock egress door in the form of the revolving door88. The door86has an associated launching pad89between the flight chamber85and the door86to provide an area from which a user can enter the flight chamber. The door88has an associated landing pad90between the revolving door88and the flight chamber85to provide a launching area for a user leaving the flight chamber85. Short wall sections87,87and93,93between the doors86,88and the flight chamber85define the launching pad90.

FIG. 19is an embodiment similar to the embodiment ofFIG. 18, except that it includes a pair of isolation doors91and92positioned between the launching pad89and the flight chamber85and a pair of isolation doors94and95positioned between the landing pad90and the flight chamber85. These isolation doors91,92and94,95may be any kind of hinged doors. Preferably, they hinge inwardly relative to the launching pad89and the landing pad90. These doors may be sealed, if desired.

FIG. 20is similar to the flight chamber configuration ofFIG. 19, except that the revolving doors86and88are positioned immediately adjacent to the flight chamber85. Thus, the short wall sections defining the launching pad89and the landing pad90ofFIG. 19have been eliminated fromFIG. 20. Thus, users entering the flight chamber85or leaving the flight chamber85enter or leave from the open triangular area96of the revolving doors86and88. In this particular embodiment, the remaining triangular areas of the revolving door are closed, although this is optional. Further, this particular embodiment may or may not include the isolation doors91,92and94,95shown inFIG. 19.

FIGS. 21 and 22represent a still further embodiment of a flight chamber configuration. In these figures, the flight chamber98is surrounded by a staging area99as shown. Specifically, the staging area99extends around the entire periphery of the flight chamber98and is defined by wall102, ceiling103and floor104sections. If desired, a safety net100may be hung between the flight chamber98and the staging area99to prevent users from falling out of the flight chamber during use. An airlock ingress/egress door in the form of the revolving door101provides ingress and egress access to the staging area99.

Although the description of the preferred embodiment has been quite specific, it is contemplated that various modifications could be made without deviating from the spirit of the present invention. Accordingly, it is intended that the scope of the present invention be dictated by the appended claims rather than by the Description of the Preferred Embodiment.