Abstract:
In a fabric enclosure such as a tent wall there is provided an opening in the fabric panel with a fabric closure panel for closing the opening having a hinge line along one side connecting the closure panel to the wall panel. The opening and the closure panel each define an edge thereof opposite to the hinge line which is curved from an end at the hinge line around to an opposite end separated from the hinge line by a non-flexible rod with the edge of the closure panel overlapping the edge of the opening for closure thereon and a flexible bowing strip attached to the edge of the closure panel which is forced into a bowed shape to apply tension to the closure panel tending to maintain the panel flat.

Description:
This application claims the benefit under 35USC 119 of the filing date of provisional application 60/610,178 filed Sep. 16, 2004. 
     This application is a continuation in part of patent application Ser. No. 11/225,881, filed Sep. 14, 2005 and now issued to U.S. Pat. No. 7,882,850. 
    
    
     The invention provides a new door and frame assembly to replace the common zipper door on camping tents, outdoor dining tents and screen rooms. 
     BACKGROUND OF THE INVENTION 
     The common camping, dining or screen tent typically utilizes a zippered flap of material or screen to act as the doorway into and out of the tent. To enter or exit the tent it is necessary to bend down, open the zipper, bend over and pass through the doorway, and then turn around and close the zipper. Because of the loose material, it often requires two hands, and is often difficult if a person is carrying something. 
     Considered broadly, tents disclosed herein are of a portable type, comprised of fabric roofs and walls and often including waterproof fabric floors. The tents are usually supported by rigid metal, fiberglass, or composite poles and frame. The entry method into and out of the tent is by means of a fabric zippered door. 
     SUMMARY OF THE INVENTION 
     It is one object of the invention to provide an improved fabric enclosure with an improved door construction providing an opening with a closure panel in one wall. 
     According to one aspect of the invention there is provided a fabric structure comprising: 
     a fabric wall panel of the fabric structure defining a plane of the panel and defining side edges of the wall panel and a bottom of the wall panel for resting along a ground surface; 
     an opening in the fabric wall panel; 
     a fabric closure panel for closing the opening having a hinge line along one side connecting the closure panel to the wall panel; 
     wherein the fabric wall panel at the opening and the fabric closure panel each define an edge thereof opposite to the hinge line with the edge of the fabric closure panel overlapping the edge of the fabric wall panel at the opening for closure thereon; 
     wherein the edge is curved; 
     a flexible bowing strip attached to the edge of the fabric closure panel opposite to the hinge line, which bowing strip is forced into a bowed shape from an initial different shape such that the flexible bowing strip tends to return to the initial shape generating forces in the bowing strip biasing ends of the bowing strip apart; 
     and wherein the flexible bowing strip is attached to the edge of the closure panel such that the forces in the bowing strip biasing the ends of the bowing strip apart act to apply tension to the closure panel tending to maintain the panel flat. 
     According to an important aspect, the curved edge extends from a top end at the hinge line around to an opposite end at position at a floor of the fabric wall panel, which position is spaced from the hinge line. 
     Preferably there is provided a straight non-flexible, stiff brace attached to the bottom edge of the closure panel from said position to the hinge line. 
     Preferably there is provided a connecting member attached to the closure panel at the position to receive an end of the brace and an end of the bowing strip. 
     Preferably the connecting member is a molded piece having a first receptacle for the end of the brace and a second receptacle for the end of the bowing strip. 
     Preferably the brace is attached to the edge of the closure panel by at least one sleeve on the edge of the closure panel. 
     Preferably there is provided a fabric door sweep attached to the bottom edge of the closure panel which engages the ground surface in the closed position. 
     Preferably the fabric wall panel is arranged to have no sill portion thereof extending upwardly from the ground surface at the bottom edge at the opening. 
     Preferably the fabric wall panel is arranged to lie substantially flat against the ground surface at the bottom edge at the opening. 
     Preferably the fabric wall panel includes a strap lying substantially flat against the ground surface at the bottom edge at the opening. 
     Preferably there is also a second flexible bowing strip attached to the edge of the opening opposite to the hinge line, which second bowing strip is forced into a bowed shape from an initial different shape such that the flexible bowing strip tends to return to the initial shape. 
     Preferably the flexible bowing strip is attached to the edge of the closure panel by a sleeve on the edge of the closure panel. 
     Preferably each end of the bowing strip is contained in a respective top and bottom retainer pockets attached to the fabric wall panel so as to transfer the tension from the bowing strip into the fabric wall panel. 
     Preferably the top retainer pocket is mounted on the fabric wall panel for pivotal movement of the retainer pocket relative to the fabric wall panel about the hinge line, where the hinge line lies at an angle to the bowing strip at the end of the bowing strip. 
     Preferably the bottom retainer pocket is attached to the fabric wall panel and defines a rigid pocket into which an end of the flexible bowing strip is inserted so as to be rigidly connected to the straight non-flexible door brace which is inserted into the other side of the pocket. 
     Preferably there is provided a fastening system for releasably fastening the overlapping edges together. 
     Preferably the hinge line lies in a plane of the fabric wall panel and is inclined in that plane in a direction such that, when viewed in a front elevation of the fabric closure panel, the hinge line is inclined to the vertical in a direction such that a top end of the hinge line is located to a side of a bottom end of the hinge line toward the closure panel. 
     The arrangement described in more detail hereinafter utilizes a fabric door panel with a rigid frame comprising straight and arched segmented metal, fiberglass, or composite rods. The door frame, as part of the tent wall, also utilizes a segmented metal, fiberglass, or composite rod to provide opening shape. The rods are assembled into one piece and when attached to the tent fabric form a combined straight and bent segment-of-a-circle arch. The rod is attached to the tent fabric by hoops of fabric around the periphery of the door and door opening. Overlapping fabric edges between the door and the frame in the tent wall prevent fly and mosquito egress. The door pivots on a reinforced fabric hinge. The door is opened in a conventional fashion, by pulling on a handle on one side, stepping through the doorway and closing the door behind. Velcro or magnetic closures keep the door closed. On most sloped wall tents, the door is also self-closing. 
     One variation of this invention would be the use of compressed gas tubes to provide the arched shape to the fabric door panel and door frame. 
     There is referenced a number of times herein the use of segmented rods for use as the bowing strip. Another variation would be the use of a continuous rod that rolled up for travel (somewhat like a tape measure). Another variation of this invention would be the use of non-segmented metal, fiberglass or composite flat bar to provide the arched shape to the fabric door panel and door frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One embodiment of the invention will now be described in conjunction with the accompanying drawings in which: 
         FIG. 1  is an isometric view of a conventional pole supported tent showing the tent door and frame on one side of the tent and including the closure according to the present invention. 
         FIG. 2  is an elevational view of the embodiment of  FIG. 1  showing the opening tension hoop with the door tension hoop not shown for clarity. 
         FIG. 3  is an elevational view of the embodiment of  FIG. 1  showing the opening tension hoop and top bowing strip retainer, viewed from inside the tent looking out. 
         FIG. 4  is an elevational view of the embodiment of  FIG. 1  showing the door tension hoop and top bowing strip retainer. 
         FIG. 5  is an elevational view of the embodiment of  FIG. 1  showing the door tension hoop and bottom bowing strip retainer. 
         FIG. 6  is a section view of the embodiment of  FIG. 1  showing the door tension hoop and bottom bowing strip retainer along the lines  6 - 6  of  FIG. 5 . 
         FIG. 7  is a section through the opening tension hoop and door tension hoop along the lines  7 - 7  of  FIG. 1  and showing the general relationship between the two when the door is closed. 
         FIG. 8  is an isometric view of a tent showing a second embodiment of the closure. 
         FIG. 9  is an elevational view of the door bottom brace and door bottom brace retainer. 
         FIG. 10  is an elevational view of the door tension hoop, door bottom brace and corner bowing strip retainer. 
         FIG. 11  is an elevational view of the opening in the tent showing the tension hoop and bottom bowing strip retainer, viewed from inside the tent looking out. 
         FIG. 12  is a cross-section along the lines  12 - 12  of  FIG. 8 . 
     
    
    
     In the drawings like characters of reference indicate corresponding parts in the different figures. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiment comprises a number of components attached to the fabric tent wall  1 , which include: 
       1 —fabric tent wall, 
       2 —fabric door, 
       3 —stiffening fabric at hinge line; 
       4 —flexible bowing strip-opening frame; 
       5 —tension hoop—opening frame; 
       6 —stiffened edge—opening frame; 
       7 —bowing strip retainer—opening frame (one at the top of the door and one at the bottom); 
       8 —bowing strip hook and loop restraint—opening frame (one at the top of the door and one at the bottom); 
       9 —flexible bowing strip—door frame; 
       10 —tension hoop—door frame 
       11 —stiffened edge—door frame; 
       12 —bowing strip retainer—door frame top; 
       13 —bowing strip retainer—door frame bottom; 
       14 —hook and loop/magnetic closure; 
       15 —ground spike loop—side wall; 
       16 —handle; 
       17 —ground spike loop—corner; 
       18 —conventional tent; 
       19 —fabric hinge centerline; 
       20 —reinforcement pad. 
     The invention provides a door assembly and an opening assembly. A general arrangement of the two assemblies is shown in  FIG. 1 . 
     The door assembly provides a straight segmented flexible bowing strip door frame  9  (constructed of metal, fiberglass or composites), which is inserted into a semi-circle-shaped door frame tension hoop  10  (constructed of fabric) attached to the fabric door  2 . The ends of the flexible bowing strip door frame  9  are positioned and restrained by the bowing strip retainers  12  and  13  (constructed of reinforced plastic or fabric) at the top and bottom of the door. Insertion of the bowing strip  9  into the semi-circle shaped tension hoop  10  and bowing strip restraint by the bowing strip retainers  12  and  13  causes the door fabric to be stretched tight and maintain the shape bowing strip  9  into the semi-circle-shaped door frame tension hoop  10 . A fabric handle  16  provides a convenient grasp for opening the door. 
     The opening assembly consists of a straight segmented flexible bowing strip opening frame  4  (constructed of metal, fiberglass or composites), which is inserted into a semi-circle-shaped opening frame tension hoop  5  (constructed of fabric) attached to the tent wall. The ends of the flexible bowing strip opening frame  4  are positioned and restrained by the bowing strip retainers  7  (constructed of reinforced plastic or fabric) and bowing strip hook and loop restraints  8  at the top and bottom of the door opening. Insertion of the straight bowing strip  4  into the semi-circle-shaped opening frame tension hoop  5  and bowing strip restraint by the bowing strip retainers  7  and bowing strip hook and loop restraints  8  causes the tent wall to be tight and the door opening to match the shape and size of the door. A reinforcement pad  20  provides additional strength to the fabric of the assembly. 
     The door assembly has a stiffened edge  11  which is a band of stiffer material fastened to the fabric extending around the semi-circle defined by the inside of the door frame tension hoop  10  which mates with a stiffened edge  6  on the outside of the opening frame tension hoop  5 . The purpose of the stiffened edge is to restrict mosquito and fly egress into the tent. At intervals along the stiffened edge, hook and loop/magnetic closures  14  provide attachment of the door assembly to the opening assembly in order to resist the wind from opening the door assembly. A stiffening fabric at the hinge line  3  allows the door to rotate about the plane of the tent wall. Side wall ground spike loop  15  allows attachments of the stiffening fabric to the ground to maintain the position of the door frame tension hoop  10  relative to the opening frame hoop  5 . 
     The embodiment herein has the following features: 
     In a camping, dining or screen tent, the use of a rigidly framed door assembly and rigidly framed opening assembly, the combination of which provides convenient hinged door access to and from the tent. 
     The rigidly framed door assembly comprising of a straight segmented flexible bowing strip door frame  9 , held in tension in a semi-circle shape by bowing strip retainers  12  and  13 . 
     The rigidly framed opening assembly comprising of a straight segmented flexible bowing strip opening frame  4 , held in tension in a semi-circle shape by bowing strip retainers  7  and bowing strip hook and loop restraints  8 . 
     The door frame tension hoop  10  and opening frame tension hoop  5  which give shape to the door and tent wall fabric. 
     The stiffened edges  6  and  11  to resist mosquitoes and flies from entering the tent. 
     The hook and loop/magnetic closures  14  to prevent the unintended opening of the door assembly. 
     The arrangement of  FIGS. 8 to 12  is similar to that described above so that only the important differences will be described as follows. 
     The door assembly provides a straight segmented flexible bowing strip door frame  30  constructed of metal, fiberglass or composites similar to that previously described. This is inserted into an arc-shaped door frame tension hoop  31  constructed of fabric attached to the fabric door  2 . The top end of the flexible bowing strip door frame  30  is positioned and restrained by the bowing strip retainer at the top of the door as shown in the previous embodiment in  FIG. 2 . 
     The bottom of the bowing strip  30  as shown in  FIG. 10  is inserted into a cylindrical receptacle  33  in a bottom stiff retainer  32  constructed of reinforced plastic or metal at the bottom of the door. The door assembly also provides a straight segmented non-flexible or stiff door bottom brace  34 , constructed of tubular metal, fiberglass or composites so as to be resistant to flexing, which is received in a receptacle  35  in the retainer  32 . The retainer  32  is attached to the door  2  at the bottom corner by stitching or adhesive so as to provide a holder for the bowing strip and the brace. The retainer  32  is relatively stiff so as to prevent twisting at the bottom corner and to hold the brace and bowing strip connected at a fixed angle at the bottom corner allowing them to move together as the door is opened. 
     The brace  34  is inserted into a straight door frame tension hoop or sleeve  36  constructed of fabric and attached to the fabric door  2  along the bottom edge of the door. At the other end of the brace  34 , the brace is received in a receptacle  37  of a retainer  38 . The retainer  38  is stitched to the fabric of the tent at the hinge line so as to allow the end of the brace to pivot about the hinge line  19 . 
     The ends of the door bottom brace  34  are therefore positioned and restrained by the bowing strip retainers  32  and  38  at the bottom of the door. Insertion of the door bottom brace  34  into the straight tension hoop  36  causes the door fabric to stay flat upon the ground surface when in the closed position. 
     Insertion of the bowing strip  30  into the arc-shaped tension hoop  31  and bowing strip restraint by the bowing strip retainers  32  and  5  causes the door fabric to be stretched tight and maintain the shape of the door panel. A fabric handle  16  shown in  FIG. 8  provides a convenient grasp for opening the door. 
     In this way the curved edge defined by the bowings strip at the edge of the door extends from a top end at the hinge line around to an opposite end at position defined by the retainer  32  at the floor of the fabric wall panel where the position defined by the retainer is spaced from the hinge line by the length of the brace. 
     The bowing strip is curved sufficiently that it meets the retainer  32  at an angel to the brace which is greater than 90 degrees. This provides a sufficient curvature on the bowing strip to hold the door tensioned and its fabric flat and to provide tension on the fabric attached to the brace. Also the retainer  32  is sufficiently rigid that it maintains the spatial relationship between the brace and the bowing strip, both in angle rotation and planar position. It effectively couples the brace to the bowing strip, so that the two in combination act much like the original sprung hoop. The brace is held in place in the retainers attached to the door panel fabric by the fact that its length is slightly greater than the distance between the retainers. 
     The opening in the tent  1  shown in  FIGS. 8 and 11  is defined by an edge  40  of the fabric tent  2  which is shaped to match the door with a bottom edge  41  matching the length of the brace  34  and an arched top portion  42  extending from the bottom  41  upwardly and around to the hinge line  19  shown in  FIG. 3  at the top. A second bowing strip  43  similar in construction to the first is inserted into an arc-shaped fabric hoop  44  at the edge  42 . The ends of the second flexible bowing strip  43  are positioned and restrained by the bowing strip retainers  45  at the bottom and  7  shown in  FIG. 3  at the top. 
     The bowing strip  43  is also held in place by a hook and loop restraint  46  at the bottom and by a similar element  8  at the top. These are located adjacent the retainers and act to hold the bowing strip in place when inserted in the retainers. Other arrangements for holding the bowing strip in place can be provided. Bending of the straight bowing strip  43  into the arc-shaped opening frame tension hoop  44  and bowing strip restraint by the bowing strip retainers  45  and bowing strip hook and loop restraints  46  causes the tent wall to be tight and the door opening to match the shape and size of the door. 
     A reinforcement pad  47  at the bottom edge of the door opening on the side away from the hinge line  19  provides additional strength to the fabric of the assembly and carries the forces from the retainer  45 . A door sill strap  48  lays flat on the ground and connects the left side fabric tent wall  1  to the right side fabric tent wall  1  and provides integrity in the opening size and holds the tent wall  1  in a generally planar orientation. Thus the opening assembly and door assembly are held coplanar by ensuring alignment of and maintaining spacing between the bottom left and bottom right sides of the door opening. The ends of the strap  48  are held in place by ground spike loops  50 . 
     The door assembly has a stiffened edge  51  which is a band of stiffer material fastened to the fabric extending around the arc defined by the inside of the door frame tension hoop  31  which mates with a stiffened edge  53  on the outside of the opening frame tension hoop  44 . The purpose of the stiffened edge is to restrict mosquito and fly egress into the tent. At intervals along the stiffened edge, closures  14  shown on  FIG. 7  provide attachment of the door assembly to the opening assembly in order to resist the wind from opening the door assembly. These can be of the hook and loop or magnetic type. A door sweep  52  constructed of reinforced fabric rests on the ground at the bottom strap  48  and helps to restrict mosquito and fly egress into the tent. A stiffening fabric at the hinge line  19  allows the door to rotate about the plane of the tent wall. The side wall ground spike loop  50  allows attachment of the stiffening fabric to the ground to maintain the position of the door frame tension hoop  31  relative to the opening frame hoop  44 . 
     The embodiment herein has the following features: 
     In a camping, dining or screen tent, the use of a rigidly framed door assembly and rigidly framed opening assembly, the combination of which provides convenient hinged door access to and from the tent. 
     The rigidly framed door assembly comprises a flexible bowing strip door frame, held in tension in an arc shape by bowing strip retainers in combination with a non-flexible door bottom brace, held in place by bowing strip retainer and door bottom brace retainer. 
     The rigidly framed opening assembly comprises a flexible bowing strip opening frame, held in tension in an arc shape by bowing strip retainers and bowing strip hook and loop restraints. 
     The door frame tension hoop, opening frame tension hoop, and door sill strap which give shape to the door and tent wall fabric. 
     The stiffened edges and door sweep to resist mosquitoes and flies from entering the tent. 
     The hook and loop/magnetic closures to prevent the unintended opening of the door assembly. 
     The fabric wall panel is arranged to have no sill portion thereof extending upwardly from the ground surface at the bottom edge at the opening. 
     The fabric wall panel is arranged to lie substantially flat against the ground surface at the bottom edge at the opening. 
     The fabric wall panel includes a strap lying substantially flat against the ground surface at the bottom edge at the opening. 
     Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the Claims without department from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.