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CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority from U.S. Provisional Application having Ser. No. 60/178,102, filed Jan. 26, 2000 and entitled “Tent With Retractable Fly,” which Provisional Application is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to canopy structures such as a tent and various other shelters. In particular, the present invention relates to the tent having a retractable fly. 
     BACKGROUND OF THE INVENTION 
     Tents and various other shelters come in a variety of sizes, shapes and configurations and are used to provide portable, temporary shelter during activities such as camping or other recreational activities. Typically, tents include a fabric shell and a framework of elongate poles to support the shell. 
     Shelter against precipitation is typically provided by water repellent or water-resistant material that forms the shell. However, during the appropriate weather conditions, water repellent or water-resistant material may cause condensation to collect on the inside of the tent. Such condensation causes discomfort to the occupants, dampness to clothing and gear, and a potential for growth of mildew. 
     In an attempt to overcome the shortcomings of such material, the use of “breathable” material, or vents made of screen or mesh may be employed. However, such configurations have limited water repellant characteristics and are difficult to seal. 
     It is well known to attach a protective, water-repellant or water-resistant covering (commonly known as a “fly”) to a tent to offer additional protection from outdoor elements (e.g., rain, snow, bugs, etc.) and ventilation to its occupants. In a general sense, such known applications provide protection from outdoor elements and ventilation. When flies are employed, the shell may include venting without having to provide water repellant seals. 
     Although such flies are commonly used, such flies have several distinct drawbacks. Such known configurations are typically characterized either by their lack of adjustability or inconvenience. As a result, such known applications are generally not well suited for situations where egress of tent to make positional adjustments to the fly is not desirable or is inconvenient. First, for example, a camper must exit the tent when he or she wishes to adjust the fly—a significant drawback when it is raining, when there are a lot of insects, etc. Second, known ways of adjusting flies comprise inefficient steps. Several known flies require several repetitive steps to adjust a fly to a desired position. Third, even when adjustable, the flies of such tents are not used as intended because of their inconvenience and therefore the benefits of such “adjustability” are not realized by the user. 
     Thus, there is a continuing need for a tent having a fly that is moveable between a substantially extended position and a substantially retracted position, that provides a water repellant or water resistant protection from the elements, that allows for the interior of the tent to be ventilated, that provides the occupants with a “skylight” or window to enjoy the outdoors, that allows and encourages use and engagement of such vents and skylights, and that has an actuation interface which is operable from inside the tent in a manner that facilitates use and enjoyment. 
     Accordingly, it would be advantageous to have a tent with a fly adapted to be substantially extended or retracted (i.e. closed or opened) without the user having to exit the tent. It would also be advantageous to have a tent with fly that includes a portal that allows for ventilation and/or viewing that may be uncovered by adjustment of the retractable fly. It would further be advantageous to have a retractable fly that requires a minimum amount of assembly. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a tent system. The tent includes a tent having a shell and a frame configured to support the shell. The tent system also includes a sheet adjustably coupled to the tent. The sheet may adjust between a substantially extended position and a substantially retracted position by a person inside of the tent. 
     The present invention also relates to a tent system. The tent system includes a tent including a shell and a frame adjacent the shell. The tent system also includes a sheet coupled to the shell, and means for adjusting the sheet between a substantially extended position to a substantially retracted position. 
     The present invention further relates to a method for selectively adjusting a fly from inside a tent relative to an underlying shell. The method includes providing a cord having a first end attached to the fly and a second end disposed inside the tent, and actuating the position of the fly by adjusting the length of cord disposed inside the tent. 
     The present invention further relates to a covering for a tent having a shell and a frame configured to support the shell. The covering includes a sheet adjustably coupled to the tent. The sheet may adjust between a substantially extended position and a substantially retracted position by a person inside of the tent. 
     The present invention further relates to various features and combinations of features shown and described in the disclosed embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 and 2 are perspective views of a tent and a fly according to an exemplary embodiment of the present invention. 
     FIG. 3 is a fragmentary elevation view of the tent of FIG. 1 without an attached fly. 
     FIG. 4 is an exploded elevation view of the tent of FIG.  3 . 
     FIG. 5 is an exploded fragmentary elevation view of the tent of FIG.  4 . 
     FIG. 6 is an exploded fragmentary elevation view of the tent of FIG.  4 . 
     FIG. 7 is a fragmentary elevation view of the tent of FIG. 4 taken along line  7 — 7 . 
     FIG. 8 is a fragmentary elevation view of a corner of fly of FIG.  1 . 
     FIG. 9 is a fragmentary sectional view of the tent of FIG. 1 taken along line  9 — 9 . 
     FIG. 10 is a fragmentary sectional view of the tent of FIG. 2 taken along line  10 — 10 . 
     FIG. 11 is a fragmentary sectional view of the tent of FIG. 9 taken along line  11 — 11 . 
     FIG. 12 is a fragmentary elevation view of the tent of FIG. 1 taken along line  12 — 12 . 
     FIG. 13 is a side elevation view of a pivot mechanism of FIG.  3 . 
     FIG. 14 is a fragmentary sectional view of the pivot mechanism of FIG. 13 taken along line  14 — 14 . 
     FIG. 15 is front elevation view of a fly pole of the fly of FIG.  1 . 
     FIG. 16 is a fragmentary sectional view of the tent of FIG. 9 taken along line  16 — 16 . 
     FIG. 17 is a fragmentary elevation view of the tent of FIG. 9 taken along line  17 — 17 . 
     FIGS. 18 and 19 are perspective views of an alternative embodiment of the tent of FIG.  1 . 
     FIG. 20 is a fragmentary sectional view of the tent of FIG. 19 taken along line  20 — 20 . 
     FIGS. 21 and 22 are schematic perspective views of an alternative embodiment of the tent of FIG.  1 . 
     FIGS. 23 and 24 are schematic perspective views of an alternative embodiment of the tent of FIG.  1 . 
     FIG. 25 is a schematic perspective view of an alternative embodiment of the tent of FIG. 1 
     FIG. 26 is a schematic fragmentary perspective view of the tent of FIG.  25 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1-3 illustrate a tent system  10  including a tent  11  having a frame  12  supporting a shell  14 . Tent system  10  also includes a overlaying covering or sheet (shown as a fly  16 ) configured to be selectively adjusted by an occupant “inside” of shell  14 . “Inside” of shell  14  is intended to mean that the occupant substantially inside of the shell  14  and encompass alternative embodiments wherein the occupant extends a portion of his or her body (e.g., hand, arm, etc.) outside of the shell to selectively adjust fly  16 ). Selective adjustment of fly  16  may take many of a variety of forms, including pivoting, sliding, rolling, “bunching,” stretching, etc. 
     Frame  12  includes a plurality of segmented poles  108  each including an end  20  and an end  22 . According to a preferred embodiment, each frame pole  18  is formed from four substantially straight sections  24  and a bent section  26 , and is made from a rigid material (e.g., aluminum, plastic, etc.) and connected by an elastic or “bungy” cord attached to the outer sections. According to an alternative embodiment, frame poles  18  may be comprised of a plurality of substantially straight sections and an elbow configured to provide a bend in pole  18 . According to alternative embodiments, poles  18  may have various shapes depending upon the desired shape and size of the tent and may be made from a variety of materials (e.g., plastic, metal bands, etc.) designed to provide the desired characteristics. 
     As shown in FIGS. 4 and 9, shell  14  defines a space for users to occupy and store gear. Shell  14  is formed by a plurality of flexible fabric panels or sheets connected by seams  30  which together comprise walls  32 , ends  34 ,  36 , a floor  38 , and a roof  40 . 
     Ends  34 ,  36  of shell  14  preferably include multiple layers of material for selective arrangement for privacy, ventilation, etc. According to a preferred embodiment, ends  34 ,  36  include a vent  42  and/or an imperforate sheet  44 . Either or both of vent  42  and imperforate sheet  44  may be provided with a closure mechanism  46  (e.g., a zipper, latch-hook fastener, etc.) which may be selectively opened from inside and/or outside tent  11 . When end  34  and/or end  36  are configured to provide the user with ingress to and egress from the space defined by shell  14 , both vent  42  and imperforate sheet  44  include closure mechanism  46 . According to an alternative embodiment, imperforate sheet  44  is made from material that has any of a variety of degrees of light transmission (e.g., between opaque and transparent). 
     According to a preferred embodiment, except for sheets or panels that provide ventilation functions, walls  32 , floor  38 , and ends  34  and  36  are made from water repellant or water resistant material. According to an alternative embodiment, portions of roof  40 , walls  32 , floor  38 , or ends  34  and  36  may be formed from “breathable” material (i.e., material having a lesser degree of water resistance). 
     As shown in FIGS. 2-4, shell  14  further includes one or more roof portals  48  to provide a variety of functions (e.g. ventilate air, to provide a “window” or “skylight,” etc.). Portals  48  are located in roof  40  adjacent end  34  and/or end  36 . According to a preferred embodiment, portal  48  includes a vent  50  formed by netting or screen made from nylon. According to an alternative embodiment, portals  48  are made of imperforate material with any of a variety of degrees of light transmission (i.e., between opaque and transparent). 
     Referring to FIG. 7, shell  14  also includes four corner assemblies  52  configured to interface with frame  12  and fly  16 . Each corner assembly  52  includes a ring  54  attached to shell  14  by a strap  56  formed into a loop, a female portion  58  of a snap connector  60 , preferably a side release buckle, attached to ring  54  by a strap  62 , and a key  64  also attached to ring  54 . Female portion  58  of snap connector  60  is configured to couple with a male portion  66  of snap connector  60  (shown in FIG.  8 ), which is attached to fly  16  by a strap  108 . Key  64  includes a post  68  configured to be inserted into end  20  of poles  18 . 
     Referring to FIGS. 3-6, shell  14  is coupled to frame by a hub  70  and a plurality of hooks or clips  72 . Hub  70  includes a member  76  and is coupled to frame  12  by a strap  74  looped around member  76  and attached (e.g., sewn or stitched) to shell  14 , and includes a plurality of receptacles  78  configured to receive poles  18  of frame  12 . According to a preferred embodiment, hub  70  is made of plastic (e.g., thermoplastic, thermoset, etc.). Poles  18  are bent or flexed so that one end  20  couples with hub  70  and the other end  22  receives post  68  of key  64 . As such, floor  38  of shell  14  is expanded or stretched and clips  72  are attached to poles  18  to form a free-standing structure resistant to collapse or dislodgment. End  20  of pole  18  is configured to receive key  64  of corner assembly  52  of shell  14 , and the other end is configured to not receive key  64  so that pole  18  is orientated in the designed manner. For example, end  22  of pole  18  may include an insert  88  so that key  64  will not fill in end  22  of pole  18  and to provide additional support for the portion of pole  18  that is inserted into hub  70 . 
     As shown in FIGS. 3,  4 , and  6 , clips  72  are attached to shell by straps  80  which extend from the interface of ends  34  and  36  and walls  32  or roof  40 . Ends  82  of each strap  80  are coupled (e.g., sewn or stitched) to shell  14  to form a loop  84  which passes though an aperture  86  on clip  72  to secure clip  72  to shell  14 . Clip  72  is generally “J-shaped” and provides an interference or “snap” fit engagement between shell  14  and frame pole  18 . According to a preferred embodiment, clip  72  is made from a semi-flexible material (e.g., plastic commercially available as a product designated “DELRIN” from E. I. du Pont de Nemours and Company of Wilmington, Del., or other materials having similar properties) that flexes as clip  72  is being attached to pole  18  and returns to its original shape. 
     Referring to FIGS. 1,  2 ,  9  and  11 , fly  16  is configured to overlay at least a portion of shell  14  and have adjustable movement (e.g., pivoting between a substantially extended position and a substantially retracted position, or the like) for selectively exposing portions of shell  14  and/or tent  11 . Fly  16  is made of a plurality of sheets or panels that are configured to provide water repellant or water resistant protection to shell  14  and its contents and occupants. Fly  16  includes a main sheet  104  and a retractable sheet  106  operably coupled to main sheet  104 . 
     Main sheet  104  is configured to cover substantially the entire shell  14  except ends  34  and  36  and portal  48 . The arrangement is configured to provide increased insulation without decreasing ventilation by providing a space formed between main sheet  104  and shell  14 . This space between fly  16  and shell  14  is provided by the arrangement of shell  14 , frame  12  with hub  70 , and fly  16 . 
     Main sheet  104  of fly  16  includes an aperture  110  that is approximately the size and shape of portal  48  of shell  14  and is configured to open portal  48  to the outside environment for ventilation viewing the outdoors, lighting the interior of tent  11 , etc. A strip  111  of material spans the end of main sheet  104  to provide additional structural strength to main sheet  104 . 
     Referring to FIG. 12, main sheet  104  also includes side strap assemblies  112  configured to provide a variety of functions (e.g., staking tent  110  to structure or the ground, attaching equipment, etc.). One end of side strap assemblies  112  is attached to main sheet  104  of fly  16 . Side strap assemblies  112  each include a buckle  114  attached to main sheet  104  of fly  16  and a strap  116  threaded through buckle  114 . This coupling of strap  116  and buckle  114  is configured to provide for a non-slip threading arrangement. As such, a loop  118  may be formed that has variable dimensional characteristics. A ring  120  may be coupled to loop  118  of strap  116  and is configured to provide an interface for the desired engagement. For example, a stake (not shown) can be inserted through ring  120  and pushed or pounded into the ground, ring may be coupled to adjacent structure (e.g., tied to a tree with a rope), or ring  120  may be used to attach equipment for organization and loss prevention purposes, etc. 
     As shown in FIGS. 11 and 12, retractable sheet  106  of fly  16  is attached to main sheet  104  by any of a variety of methods and arrangements. According to a preferred embodiment, one end  128  of retractable sheet  106  is sewn or stitched to main sheet  104  working with an adhesive (which is intended to provide additional strength and water resistant properties). Alternatively, main sheet  104  and retractable sheet  106  are integrally formed. Retractable sheet  106  may be attached to main sheet  104  at a variety of locations according to the desired configurations of fly and/or tent  11 . As shown in FIGS. 1,  2 , and  9 - 12 , retractable sheet  106  is attached to main sheet  104  at approximately the midpoint of main sheet  104 . 
     Referring to FIGS. 7,  8 ,  13 , and  14 , fly  16  is coupled to shell  14  by snap connectors  60 , by engagement between an actuation mechanism (shown as a pair of pivot mechanisms  92 ) and a fly pole  94 , and by an elastic cord  124 . As shown in FIG. 8, male snap connectors  66  are attached to the corners of main sheet  104  with straps  108  and are configured to couple to female portion  58  of snap connectors  60  of corner assemblies  52  attached to shell  14 . 
     Pivoting of fly is provided by cooperation among pivot mechanisms  92 , fly pole  94 , an actuation interface (shown as a pull cord  122 ), and a biasing member (shown as a elastic cord  124 ). As shown in FIGS. 13 and 14, each pivot mechanism  92  includes a base  96  attached to shell  14  (e.g., sewn or stitched), and provides a reinforcing structure for a pivot member  98 . Pivot member  98  extends from base  96  and includes an eyelet or grommet  100 . Grommet  100  is configured to receive end  102  of fly pole  94 . According to a preferred embodiment, pivot member  98  is a single length of material (e.g., any of a variety of flexible material such as nylon, polyester, etc.) that is attached (e.g., sewn or stitched working with an adhesive) at its ends to base  96  such that its middle section may be folded onto itself and held together by grommet  100 . In operation, ends  102  of fly pole  94  are inserted into grommets  100  on opposite walls  32  of shell  14  such that when fly  16  is retracted or extended, pivot member  98  twists to allow the desired amount of movement of fly pole  94 . According to a particularly preferred embodiment, pivot mechanism  92  is attached to shell  14  at an approximately 45° angle and grommet  100  is also at an approximately 45° angle. 
     A sleeve  126  is disposed along an end  128  of retractable sheet  106  and is configured to receive fly pole  94 . Ends  102  of fly pole  94  have a reduced diameter and are configured to fit in grommets  100  of pivot mechanism  92 . As such, fly pole  94  of retractable sheet  106  is adapted to pivot about pivot mechanism  92  by twisting of pivot member  98 . Pivot mechanisms  92  are accessed by ends  102  of fly pole  94  through a pair of apertures  130  in main sheet  104  of fly  16 . 
     According to a preferred embodiment shown in FIG. 15, fly pole  94  includes four substantially straight tubes or sections  132 , connected by a “bungy” cord attached to ends  102  of the outer sections. An elbow  134  is located between each section  132  and is configured to provide a “predetermined bend” between the segments of fly pole  94 . Ends  136  of elbow  134  are sized to fit into ends  138  of straight sections  132 . The “predetermined bend” is determined by the shape and relative dimensions of shell  14  (e.g., walls  32  and roof  40 ) so that fly  16  may be retracted with a minimum of interference between fly pole  94 , shell  14  and poles  18  of frame  12 . According to an alternative embodiment, fly pole  94  may be formed by a single member or tube, or a plurality of bent tubes or sections. According to any embodiment, fly pole  94  may be configured to be used on any style of tent (e.g., dome, umbrella, A-frame, etc.). 
     Referring to FIGS. 9-11 and  16 , pull cord  122  is attached at one end  140  to fly  16  by a strap  142  stitched to retractable sheet  106 . The other end  144  is threaded through a plurality of clips  146  (preferably three) and is disposed across shell  14 , over hub  70 , and through a grommet  148  in main sheet  104  and a grommet  150  in roof  40  of shell  14 . According to a preferred embodiment shown in FIG. 11, grommets  148 ,  150  are located immediately adjacent hub  70  so that force imparted by pull cord  122  when retracting fly  16  is distributed through frame  102 . 
     Clips  146  are coupled to a strap  152  that is attached to an inside surface  154  of retractable sheet  106 . Clips  146  are configured to keep pull cord  122  from obstructing the user as he or she enters or exits tent  11 , and to provide a bearing surface to assist fly  16  when being pivoted. End  144  freely hangs within space defined by shell  14  and provides an operative interface between the occupant within tent  11  and fly  16 . According to an alternative embodiment, pull cord  122  is attached to an inside surface or structure of shell (e.g., hook, latch-hook fastener, etc.). 
     Referring to FIG. 17, elastic cord  124  is coupled to shell  14  by sleeve  125 , and is threaded through rings  54  of corner assemblies  52  and coupled to corners  156  of retractable sheet  106  by a pair of clips  158 . When connected, elastic cord  124  biases retractable sheet  106  in an extended position (as shown in FIG. 1) in the direction generally indicated by the arrow. As such, pulling of pull cord  122  stretches elastic cord  124  as retractable sheet  106  is pivoted toward the open or retracted position (as shown in FIG.  2 ). According to a preferred embodiment shown in FIG. 17, a bearing  159  is disposed between cord  124  and ring  54  to reduce friction. According to a particularly preferred embodiment, bearing  159  is a plastic D-ring. 
     As shown in FIGS. 9 and 10, to retract fly  16 , the occupant pulls pull cord  122  in a generally downward direction until fly  16  is sufficiently retracted. Tension in pull cord  122  causes fly pole  94  to pivot toward hub  70  thereby stretching elastic cord  124 . When fly  16  is in a desired position, a locking device  160  slidably coupled to pull cord  122  may be used to fix fly  16  in a static position. As shown in FIG. 11, locking device  160  includes a barrel  162 , a sliding member  164 , and a spring (not shown). Pull cord  122  is threaded through barrel  162  and sliding member  164  is biased against pull cord  122  by the spring to prevent locking device  160  from sliding relative to pull cord  122 . 
     According to a preferred embodiment shown in FIG. 11, locking device  160  is attached to roof  40  of shell  14  with a strap  165  so that fly  16  may be operated (retracted or extended) with one hand. To retract fly  16 , the user pulls pull cord  122  downward; strap  165  secures locking device  160  in the same general position so that pull cord  122  may slide through barrel  162 . To extend fly, the user depresses sliding member  164  to allow pull cord  122  to slide through barrel  162  until the desired amount of fly  16  extension is reached. 
     According to a preferred embodiment, shell  14 , retractable sheet  106 , and main sheet  104  include reinforced sections  166  configured to provide additional strength to the tent and to resist wear due to use and operation. Reinforced sections  166  may be formed by any of a variety of arrangements and placed at various locations. According to a preferred embodiment, reinforced sections are formed by material having wear resistant properties. According to an alternative embodiment, reinforced section is formed by material having a greater thickness or by double layers of material that are sewn or stitched together. According to a preferred embodiment, edges of the sheets or panels have cuffs  168  formed by folded-over material and configured to provide resistance against wear and fraying. Reinforced sections  166  and cuff  168  are intended to increase the strength and durability of tent system  10 . 
     FIGS. 18-20 illustrate a tent  200 , an alternative embodiment of tent system  10  shown in FIGS. 1-17. Tent  200  includes a frame  202 , a shell  204 , and a retractable fly  206 . Frame  202  includes a plurality of poles  208   a ,  208   b , and  208   c  configured to support shell  204 . 
     Shell  204  includes walls  210 , a roof  212 , and a floor  214 , which define a space configured for storage or occupancy. Shell  204  also includes a sleeve  216  spanning from approximately a corner  2108  across shell  204  to an opposite corner  220 ; a sleeve  222  spanning from approximately another corner  224  across shell  204  and over sleeve  216  to corner  226 ; and a sleeve  228  spanning mid-points  230  of shell  204 . Sleeves  216 ,  222 , and  228  are configured to removably receive elongate poles  208   a ,  208   b ,  208   c , which are inserted through the sleeves and arcuately bent to place sleeves  218 ,  222 ,  228  and shell  204  in tension to support shell  204 . According to a preferred embodiment, sleeves  216 ,  222 ,  228  are made from nylon webbing that is sewn or stitched to shell  204 . Poles  208   a ,  208   b ,  208   c  are made of a plurality of interconnected segments and may be separated and folded for storage, transport, etc. A plurality of straps  240  are attached to shell  204  at corners  218 ,  220 ,  224 ,  226 , and mid-points  230  and include a grommet  246   a  and a grommet  246   b . Grommets  246   b  of straps  240  at corners  218 ,  220 ,  224 ,  226  receive ends  256  of poles  208   a ,  208   b . Grommets  246   a  of straps  240  at mid-points  230  receive ends  258  of pole  208   c . Grommets  246   b  of strap  240  at mid-points  230  receive ends of fly pole  260 . 
     Shell  204  further includes one or more vents  232  configured to provide a vent and/or a window for comfort and enjoyment of the occupants of tent  200 . Vents  232  are preferably made from a nylon mesh or screen configured to allow the flow of air but to keep out insects. 
     Fly  206  substantially covers shell  204  and is configured to provide protection to shell  204  and to prevent rain from entering the inside of tent  200  through vents  232 . Fly  206  is coupled to shell  204  by connector clips  242 , an elastic cord  244 , and a fly pole  260 . Clips  242  include a male end attached to shell  204  and a female end attached to fly  206 . 
     Elastic cord  244  passes through grommets  246   a  on straps  240  at corners  2108 ,  224 , and includes clips  248  that couple to fly  206  (e.g., to a ring attached to fly  206 , a loop formed by a strap attached to fly  206 , etc.) adjacent to fly pole  260 . Elastic cord  244  is made out of a stretchable material (such as a “bungy” cord or the like) and is configured to store mechanical energy to bias fly  206  in a substantially extended (or closed) position. 
     Fly pole  260  couples with grommets  246   b  of straps  240  which extend from mid-points  230  of shell  204 . Fly pole  260  includes a plurality of substantially straight segmented poles or tubes made from a rigid material (e.g., aluminum, plastic, etc.) and connected by an elastic or “bungy” cord. 
     Fly  206  also includes a pull cord  250  configured to provide the tent occupant with an operative interface with fly  206 . One end  251  of pull cord  250  is attached to a ring  242  (which is sewn or stitched to fly  206 ). Pull cord  250  lays across roof  2102  of shell  204  and crossed poles  208   a ,  208   b  of frame  202 , and passes through a grommetted aperture  254  in roof  212  of shell  204  such that another end  255  of pull cord  250  is disposed inside of shell  204 . According to a preferred embodiment, grommetted aperture  254  is located immediately adjacent to the intersection of poles  208   a  and  208   b  so that force imparted by pull cord  250  when retracting fly  206  is distributed throughout frame  202 . 
     Tent  200  is assembled by inserting poles  208   a ,  208   b  into sleeves  216 ,  222  and inserting pole  208   c  into sleeve  228 . Each of poles  208   a ,  208   b  is flexed such that ends  256  are inserted into grommets  246   b  of straps  240  of corners  218 ,  220 ,  224 ,  226 . Pole  208   c  is flexed so that ends  258  of pole  208   c  are inserted into grommets  246   a  of straps  240  at mid-points  230  of shell  204 . 
     Fly pole  260  is inserted into a sleeve  262 , which is attached to fly  206 . Fly is positioned upon shell  204  and coupled to shell  204  with clips  242 . Fly pole  260  is flexed such that an end  264  is inserted into grommet  246   b  of strap  240  at one of mid-points  230 , and an end  266  is inserted into grommet  246   b  of strap  240  at the other of mid-points  230 . 
     To retract fly  206 , the occupant inside tent  200  pulls on pull cord  250  pivoting fly  206  about mid-points  230  (toward grommetted hole  254  in roof  212 ), and stretching elastic cord  244 . Poles  208   a ,  208   b  of frame  202  provide a bearing surface for pull cord  250  as the user pulls the pull cord  250  and fly  206  retracts. When fly  206  is in the desired (retracted) position, vents  232  improve ventilation and provide a “window” or “skylight” for persons inside of tent (e.g., for star gazing). After fly  206  is retracted to a desired point, the user adjusts an adjustable grip (not shown) to secure pull cord  250  and retracted fly  206  in a static position. When the user wishes to close fly  206 , the user adjusts the adjustable grip to allow the tension in the stretched elastic cord  244  to contract and withdraw pull cord  250  from interior of tent  200 . 
     According to alternative embodiments, the poles, sleeves, straps and cords may be made from any number of a variety materials and have any number of different arrangements and configurations to provide the user with an article configured to manipulate the position of the fly. 
     According to a preferred embodiment, the straps are made from woven nylon, the shell and the fly are made from nylon sheets, thread for stitching or sewing components is made from nylon or polyester, the vents are made from nylon mesh or netting, the window is made from any of a variety of clear plastic materials, the hub is molded from plastic, poles are made from aluminum tubes, the ring and key are made from metals (e.g., aluminum) or plastic, and the clips are made from molded plastic or metal. 
     According to alternative embodiments, the actuation mechanism may have any of a variety of configurations for selectively moving fly  16  between a substantially extended position and a substantially retracted position for exposing/uncovering a portion of the tent  11 . For example, fly  16  may include alternative ways of pivoting fly  16  (e.g., a swiveling member with grommets configured to receive fly pole  94 ). Alternatively, base  96  of pivot mechanism  92  may be attached at one end so that the other end is free to twist or rotate with fly pole  94 . 
     According to an alternative embodiment, fly  16  may be configured to expose a portion of shell  14  by sliding along frame  12  or shell  104  when the occupant operates the actuation interface thereby eliminating the pivot point and/or pivot pole. As shown in FIGS. 21 and 22, a pair of elastic cords  254  attached to shell  14  may be provided to bias the fly in the substantially extended position. When the occupant pulls on pull cord  122 , elastic cords  254  are stretched and fly  16  is slid along tent  101  (and bunched up near the center of tent  11 ) to uncover or expose a portion of shell  14 . When occupant allows pull cord  122  to feed out, elastic cords  154  pull fly  16  back over shell  14  to cover up the potion of tent  11  previously exposed. Alternatively, as shown in FIGS. 23 and 24, one or more couplings  256  may be provided and configured to slidably cooperate with one or more tracks  258  attached to frame  12  or shell  14 . Alternatively, fly  16  or edge  259  is made of a material having elastic properties and configured to stretch to expose portal  48  (thereby eliminating elastic cords  154 ). As such, fly  16  may be biased in the extended position so that when the occupant pull on pull cord  122 , fly  16  or edge  1059  stretches as shell  14  is exposed. 
     According to an alternative embodiment shown in FIGS. 25 and 26, one or more flexible bands  260  having a desired spring coefficient may be provided in sleeves  262  attached to fly  16  and biased to place retractable sheet  106  in the extended or the retracted position so that manipulation of the actuation device (e.g., pull cord  122 ) by the tent occupant causes retractable sheet  106  to be rolled or unrolled, which may be “undone” due to stored mechanical energy in the bands. 
     Although only a few exemplary embodiments of the present invention have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible in the exemplary embodiments (such as variations in sizes, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, or use of materials) without materially departing from the novel teachings and advantages of the invention. For example, instead of providing a separate fly, a portion of the shell may be configured to be selectively adjusted by a person inside of the tent. Accordingly, all such modifications are intended to be included within the scope of the invention as defined in the appended claims. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of preferred embodiments without departing from the spirit of the invention as expressed in the appended claims.

Summary:
A tent with a retractable fly and a method for selectively adjusting the fly from inside the tent is disclosed. The tent includes a shell, a frame configured to support the shell, and a sheet adjustably coupled to the tent. The sheet may adjust between a substantially extended position and a substantially retracted position by a person inside of the tent. The method includes providing a cord having a first end attached to the fly and a second end disposed inside the tent, and actuating the position of the fly by adjusting the length of cord disposed inside the tent.