A collapsible structure comprising a collapsible support structure having a flexible covering disposed thereon. The support structure comprises a plurality of pole members that emanate from an upper assembly. The upper assembly has first and second hub members that, when brought into abutting contact with each other, cause the structure to assume a fully constructed configuration but when separated from each other allow the structure to become collapsed. In many embodiments, the structure can be converted from its constructed configuration to its collapsed configuration substantially with the use of a single hand. In some embodiments, 2 or more of the collapsible structures may be joined together to form a multi-unit structure. These collapsible structures may include decorative markings on the flexible cover, especially in embodiments intended for use by or entertainment of children.

RELATED PATENT APPLICATION 
   This application is a Continuation-In-Part of U.S. patent application Ser. No. 10/092,852, filed on Mar. 5, 2002 now U.S. Pat. No. 6,854,476. 


   FIELD OF THE INVENTION 
   This invention relates generally to collapsible structures and more particularly to portable tents that are constructed to be easily constructed and collapsed. 
   BACKGROUND OF THE INVENTION 
   A variety of portable tents and similar collapsible structures have heretofore been known, includint those described in U.S. Pat. No. 6,209,557 Zheng), U.S. Pat. No. 5,038,812 (Norman), U.S. Pat. No. 5,467,794 (Zheng) and U.S. Pat. No. 5,560,385 (Zheng). These portable tents and similar collapsible structures may be used by children or adults for temporary shelter, camping, as beach cabanas, play houses, etc. 
   The ease with which portable tents or other collapsible structures may be constructed and collapsed is a significant factor that determines their desirability for use in applications that require rapid or frequent construction and collapsing or easy portability, such as when these collapsible structures are used as beach cabanas, temporary play houses or while hiking, backpacking, rock climbing, etc. 
   Also, two or more portable tents or other collapsible structures are sometimes used in conjunction with one another and, in at least some applications, it may be desirable to connect two or more portable tents or other collapsible structures to one another to facilitate easy passage of humans, animals or objects from the interior of one structure to the interior of another structure. 
   Although the portable tents and similar collapsible structures have included a number of different designs, no one prior design is believed to be optimal and their remains a need in the art for the development of new and different portable tents and similar collapsible structures that are useable in new ways or are more easily collapsed/constructed or more easily portable than those of the prior art. 
   SUMMARY OF THE INVENTION 
   The present invention provides a collapsible structure (e.g., a tent, cabana, play hose, etc.) that generally comprises a plurality of pole members, a flexible covering disposed on the pole members, a plurality of strut members that are connected to the pole members and a hub assembly having upper and lower hub members, the hub assembly being attached to the pole members and the strut members. The structure is alternately disposable in a) a constructed configuration wherein the lower hub member is in abutment with the upper hub member and the flexible covering is drawn taut between the pole members and b) a collapsed configuration wherein the lower hub member is a spaced distance below the upper hub member, the pole members are closer together than they are when the structure is in its constructed configuration and the flexible covering is loosely disposed between the pole members. 
   Further in accordance with the invention, the strut members may be configured to exert an upward bias on the hub assembly when the structure is in its constructed configuration, thereby holding the hub members in substantially fixed vertical positions relative to one another and preventing the structure form inadvertently collapsing during use. When downward pressure is applied to the hub assembly, the upward bias of the strut memebrs is overcome, thereby releasing the hub assembly, allowing the upper and lower hub members to separate from one another and allowing the structure to assume its collapsed configuration. 
   Still further in accordance with the invention, the hub assembly may incorporate or be provided with locking structure(s) which mechanically lock the upper and lower hub members together when the structure is in its constructed configuration. These locating structures may be unlocked when it is desired to convert the structure to its collapsed configurations, thereby allowing the upper and lower hub members to move apart from one another and allowing the structure to assume the desired collapsed configuration. 
   Still further in accordance with the present invention, there are provided systems for attaching a plurality of collapsible structures of the forgoing type (or of any other type) to one another to form a multiple-structure assembly comprising a plurality of collapsible structures that are interconnects or linked to one another. Openings are formed in the individual collapsible structures and tunnel members are attachable to those openings so as to link the individual structures together and to provide enclosed or partially enclosed passageways between the individual collapsible structures that make up the multiple-structure assembly. 
   Still further in accordance with the present invention, collapsible structures of the forgoing type (or of any other type) may be provided with decorative markings or decorative items to impart entertaining or desired appearance(s) to the structure. For example, collapsible structures my have the appearance of a character (e.g., an animal or cartoon character). The decorative markings may be situated such that a door or flap which provides for passage into and out of the collapsible structure is positioned within an opening of the decorative object (e.g., the mouth of an animal or fish, the opening of a cave or volcano, etc.), thereby giving rise to the appearance that children or other users of the structure are passing into the opening of the decorative object as the enter the collapsible structure. In multi-unit embodiments, the decorative markings formed on each individual unit of the multi-unit assembly may fit together to give rise to a single decorative object (e.g. an elongate animal such as a snake or eel). 
   Further aspects and elements of the present invention will be appreciable to those of skill in the art upon reading the detailed descriptions of embodiments set forth herebelow. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a collapsible structure of the present invention in its fully constructed state. 
       FIG. 2  is a perspective view of the collapsible structure of  FIG. 1  in its collapsed state, immediately after removal from its optional carrying case. 
       FIG. 3  is a perspective view of the collapsible structure of  FIG. 2  in a partially constructed yet still partially collapsed state. 
       FIG. 4  is an enlarged view of portion  4 — 4  of  FIG. 3 . 
       FIG. 5  is an enlarged view of portion  5 — 5  of  FIG. 3 . 
       FIG. 6  is a perspective view of the top portion of the collapsible structure of  FIGS. 1–5  in a nearly fully constructed state. 
       FIG. 7  is a perspective view of the top portion of the collapsible structure of  FIGS. 1–5  in its fully constructed state. 
       FIG. 8  is sectional view taken vertically through the upper and lower hub members of the upper assembly of the collapsible structure shown in  FIG. 1 . 
       FIG. 9  is another sectional view taken vertically through the upper and lower hub members of the upper assembly of the collapsible structure shown in  FIG. 1 . 
       FIG. 10  is a sectional view taken vertically through the upper and lower hub members of the upper assembly of the collapsible structure shown in  FIG. 1  while in its locked in its constructed configuration. 
       FIG. 11  is a sectional view taken vertically through the upper and lower hub members of the upper assembly of the collapsible structure shown in  FIG. 1  after downward pressure has been applied to the upper hub member so as to cause the lower hub member to separate from the upper hub member and causing the structure to begin to transition from its constructed configuration to its collapsed configuration. 
       FIG. 12  is a collection of perspective views of multiple unit embodiments oc the persent invention with and without decorative markings formed thereon. 
       FIG. 13  is a diagram of an alternative hub assembly that is useable in embodiments where structure is locked in its constructed configuration with the internal angle between a longitudinal axis projected through each the strut member and an axis projected through the center of the hub member (e.g., a vertical axis) is less than or equal to 90 degrees when the structure is in its fully constructed state. 
       FIG. 14  is a diagram of another alternative hub assembly that is useable in embodiments where structure is locked in its constructed configuration with the internal angle between a longitudinal axis projected through each the strut member and an axis projected through the center of the hub member (e.g., a vertical axis) is greater than 90 degrees when the structure is in its fully constructed state. 
   


   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   The following detailed description is provided for the purpose of describing only selected embodiments or examples of the invention and is not intended to describe all possible embodiments and examples of the invention. 
     FIGS. 1 and 12  show examples of a collapsible structures  10  of the present invention in their fully constructed configurations. As shown in  FIG. 1 , each collapsible structure  10  generally comprises a) a support frame formed of a plurality of pole members  14 , a plurality of strut members  60 , pivotal connections  18  and upper and lower hub members  38 ,  32  and b) a flexible covering  22  formed of woven nylon, plastic sheet or similar material. As seen in  FIGS. 6–7  and  10 – 11 , the top end of each pole member  14  is connected by a pivotal connection  18  to the top hub member  38 , the inner end of each strut  16  is connected by a pivotal connection  18  to the bottom hub member  32  and the outer end of each strut  16  is connected by a pivotal connection  18  to a slide member on the adjacent pole  14  to form a hinged connection  20  (see  FIG. 4 ). As shown in  FIG. 12 , flexible covering  22  has a flap opening  21 , such flap  21  being securable in a closed position by a zipper  23 . 
   Optionally, as shown in  FIG. 1 , a removable panel  24  may be formed in the flexible cover  20  to and such removable panel  24  may be secured to the flexible cover by a zipper  25 . When the removable panel  24  is removed and opening is formed in the flexible cover  22  of the collapsible structure  10 . As shown in  FIG. 12 , and optional tunnel members  60  may be used in conjunction with two of the collapsible structures  10  that have optional removable panels  24  to form a multi-unit collapsible structure. The optional total member  60  preferably comprises a to the formed of flexible material such as woven by a line, plastic sheet or other suitable material. Zippers may be formed around the either end of the tunnel member  60  and may be mated or meshed with the portions of the zippers  25  that remainin on the flexible covers  22  of the collapsible structures  10  after their optional removable panels  44  have been removed. In this manner, one end of a tunnel member  60  may be connected to an opening formed in one collapsible structure  10  and the other end of that tunnel member may be connected to an opening formed in another collapsible structure  10 , thereby forming a multi-unit collapsible structure wherein the tunnel member  60  acts as a passageway between two collapsible structures  10 . Although the embodiments shown in  FIG. 12  utilize only two collapsible structures  10 , it will be appreciated that more than one removable panel  24  may be formed in some collapsible structures  10  and three or more of the collapsible structures  10  may be joined by tunnel members  60  to form multi-unit collapsible structures of this invention that incorporate more than two of the individual collapsible structures  10  of the type shown in  FIG. 1 . 
   Also, and shown in  FIG. 12 , decorative markings  62  may be formed on the flexible covers  22  and/or on the optional tunnel members  60  to impart a desired appearance. These optional decorative markings  62  may be used on single-unit or multi-unit collapsible structures  10  of this invention and may be particularly desirable when the collapsible structures  10  are intended for use as children's beach cabanas, children's playhouses, doll houses or otherwise for the entertainment of children. In these types of applications, it may be desirable for the decorative markings  62  to impart the appearance of an insect or animal. In this regard, the decorative markings  62  may be in the nature of facial features such as eyes, nose and mouth and the opened mouth of the creature may appear around the entry flap  21  of a collapsible structure  10  to give the appearance of entering through the mouth of the creature as a child passes through the entry flap  21 . 
   The collapsible structures  10  of the present invention may be easily constructed and easily collapsed and folded to a stowable configuration. When in their fully collapsed states, the collapsible structures may be inserted in two caring cases or bags. A desired carrying case (not shown) comprises a light weight, woven nylon case that has carrying handles and a zipper for opening and closing the carrying case. 
   To fully appreciate the manner in which the collapsible structure  10  may be constructed and collapsed, it is helpful to consider and understand the components, design and function of the support structure and the manner in which the flexible cover  22  is disposed upon the support structure. The support structure generally comprises a plurality of pole members  14 , a plurality of strut members  16 , a hub assembly  29  comprising an upper hub member  38 , a lower hub member  32  and an actuator  30 . The pole members  14  extend through elongate receiving channels  15  formed in the corners of the flexible cover  22  and the bottom ends of the pole members  14  are inserted into tabs  19  that are attached to and extend from the bottoms of the corners of the flexible cover  22 . Each tab preferably comprises a pocket formed of durable fabric and having an opening in its top edge such that the bottom end of a pole member  14  may be received within the pocket as shown in  FIG. 5 . When the structure  10  is collapsed, as shown in  FIGS. 2 and 3 , the pole members  14  are substantially straight, the upper and lower hub members  38 , 32  are separated and spaced apart, and the flexible cover  22  is loosely disposed. Also, hinged joints  20 , as shown in  FIG. 4 , are formed in the pole members  14  approximately midway along their length. When the hinged joints  20  are extended as shown in  FIG. 3 , they reside within the receiving channels  15  of the cover  22  between notches or cut out areas  66  formed in the fabric that defines the channels  15 . These hinged joints  20  may be folded over in the manner shown in  FIG. 2  to further collapse the structure  10 . The presence of the notches or cut away areas  66  facilitates such folding of the pole members  14  at their hinged joints  20  by preventing the fabric of the cover  22  that forms the channels  15  from bunching or binding the hinged joints  20 . 
   The process of converting the collapsible structure  10  from its collapsed configuration shown in  FIG. 2  to its constructed configuration shown in  FIG. 1  begins with unfolding of the hinged joints  20  to convert the fully collapsed structure shown in  FIG. 2  to a partially collapsed states as shown in  FIG. 3 . Thereafter, with the bottom ends of the pole members  14  inserted into their receiving tabs  19 , the user may grasp the free ends of the two cords  34 , pulling them in opposite, horizontal, outward directions as illustrated in  FIG. 6 . The cords  34  are knotted within the lower hub member  32  as shown in  FIG. 8 . Thus, as the cords  34  are pulled outwardly, the lower hub member  32  will be drawn upwardly toward the upper hub member  38  such that the upper projecting portion  40  of the lower hub member  32  will be received within a bore or concavity  39  formed in the upper hub member  38 , and the upper and lower hub members  38 ,  32  will be in abutting contact with one another. Also, as shown in  FIG. 10 , when the lower hub member  32  reaches its uppermost position in full abutment with the upper hub member  38 , the inner ends IE of strut members  16  may be slightly elevated above the outer ends OE of the strut members  16  and such upward slanting of the strut members will serve to exert a biasing force in the upward direction against the lower hub member holding it in abutting contact with the upper hub member  30  even after the user releases the cords  34 . Also, as the hub members  38 ,  32  are pulled into abutting contact with each other, the pole members  14  will bow to an arcuate configuration, giving the fully constructed structure  10  the configuration shown in  FIG. 1 . 
   When it is desired to return the structure to its collapsed state, the user may simply push downwardly on the actuator knob  30  to flex the upper assembly  12  and poles  14  downwardly to a position where the inner ends IE of the strut members  16  are now lower than the outer ends OE of those strut members  16 . This results in a loss of the upward bias on the lower hub member  32  and allows the lower hub member  32  to separate from the upper hub member  30 , as shown in  FIG. 11 . The structure may then be picked up vertically by the actuator knob  30  without constraining or preventing free retraction of the cords  34  and the structure will assume the partially collapsed configuration shown in  FIG. 3 . Thereafter, the hinged joints  20  may be folded over to place the structure  10  in its fully collapsed state as shown in  FIG. 2 . The fully collapsed structure may then be placed in an optional carrying case (not shown) or otherwise carried or transported with ease. 
   As shown in  FIGS. 10 and 11 , when the hub assembly  29  is vertically situated, a hub axis, which in the drawings is shown as a vertical axis VA, is projectable through the center of upper and lower hub members  38 ,  32 . Also, a strut axis SA is projectable through each of the strut members  16 . An internal angle A is definable between the strut axis SA and the vertical axis VA. When the structure  10  is locked in the constructed configuration shown in  FIG. 10 , angle A is more than 90 degrees and the outer ends OE of the strut members  16  are lower than or below the inner ends IE of the strut members  16 . When the structure  10  is in the unlocked configuration shown in FIG.  11 (e.g., as it is being collapsed or constructed), angle A is less than 90 degrees and the outer ends OE of the strut members  16  are above or higher than the inner ends IE of the strut members. 
   In alternative embodiments, such as those shown in  FIGS. 13 and 14 , alternative hub assemblies  29   a ,  29   b  may be utilized to mechanically or frictionally lock the structure  10  in its constructed configuration without requiring angle A to be more than 90 degrees and without requiring the outer ends OE of the strut members  16  to be above or higher than their inner ends IE. 
     FIG. 13  shows one side of an alternative hub assembly  29   a  that is useable in embodiments where the internal angle A between the strut axis SA and the vertical axis VA is less than or equal to 90° when the structure is in its fully opened or fully constructed configuration. In this alternative hub assembly  29   a , one or more downwardly extending legs G are formed on actuator cap  30   a  and the actuator cap  30   a  is at least partially rotatable, as indicated by the labeled arrows shown on  FIG. 13 . Receiving slots A are formed in legs G and protruding keys B are slidably received within slots A to stabilize and guide the up and down motion of actuator knob  30   a . The corner surface C of each leg G contacts a protruding key D formed on the lower hub member  32   a . A side slot E is also formed on a lower portion of leg G to receive another key member F that protrudes from the lower hub member  32   a . When it is desired to convert the structure from its open or constructed configuration to its collapsed configuration, the actuator cap  30  is turned in the counter-clockwise direction to the position shown in  FIG. 13 , wherein key B resides within slot A adjacent to but not within locking side slot AS, and key F resides adjacent to but not within slot E. The actuator cap  30   a  is pressed downwardly, causing corner surface C to exert downward force on lower hub  32   a , causing lower hub member  32   a  to separate from upper hub member  38   a , and allowing the structure to assume its collapsed configuration. When it is desired to convert the structure from its collapsed configuration to its open or constructed configuration, the various elements of the structure will be manipulated into the general configuration sheon in  FIG. 1  with the hub assembly  29   a  once again in the configuration shown in  FIG. 13 . Thereafter, the actuator cap  30   a  is turned in the clockwise direction. This causes key B to slide into locking side slot AS, and key F to slide into slot E, thereby locking the upper and lower hub members  38   a ,  32   a  in fixed vertical positions relative to one another and preventing the structure from inadvertently collapsing during use. 
     FIG. 14  shows one side of another alternative hub assembly  29   b  that is useable in embodiments where, when the structure is in its fully opened or fully constructed state, the internal angle A between the strut axis SA and the vertical axis VA is greater than 90°. In this alternative hub assembly  29   b , one or more downwardly extending legs G′ are formed on actuator cap  30   b . When the user presses downwardly on the actuator cap  30   b , the legs G′ extend downwardly into abutment with flange h of lower hub member  32   b . Slots A′ are formed in the legs G′ and protruding keys B′ are slidably received within slots A, thereby guiding the up and down motion of actuator knob  30   b.    
   Although exemplary embodiments of the invention have been shown and described, many changes, modifications and substitutions may be made by those having ordinary skill in the art without necessarily departing from the spirit and scope of this invention. Specifically, elements or attributes described in connection with one embodiment may also be used in connection with another embodiment provided that the inclusion or use of such element or attribute would not render the embodiment in which it is incorporated unuseable or otherwise undesirable for an intended application. Accordingly, all such additions, deletions, modifications and variations to the above-described embodiments are to be included within the scope of the following claims.