Patent Publication Number: US-7594514-B2

Title: Universal adjustably positionable masking panel system, apparatus and kit, and method of using same

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a system, apparatus and kit for providing concealment to a hunter or naturalist in an outdoor setting, which helps conceal a user thereof from game or other wildlife. The system, apparatus and kit hereof includes one or more concealment apparatus, where the apparatus includes a masking panel, a positioning arm, and a mounting support for attachment to a support substrate. More particularly, the present invention relates to a masking system, apparatus and kit, in which each concealment apparatus includes an adjustable positioning arm having dual, independently adjustable ball-and-socket clamps. The system, apparatus and kit hereof, when used with an outdoor platform such as a tree stand or a boat, provide a simplified method and apparatus for concealing a user from nearly any selected angle. 
   2. Description of the Background Art 
   Hunting blinds are normally developed for specific applications. For instance, there are distinct and separate types of blinds designed for tree stands, boats, hunting chairs, and ground enclosures. This specificity can be problematic for hunters who enjoy multiple types of hunting experiences, since it could require a user to obtain a separate blind for each type of platform used. Some examples of blind structures for use with tree stands or other observation stands are described in U.S. Pat. Nos. 5,214,872, 5,613,512, 6,202,665, and 6,510, 922. 
   A number of hub and strut systems have been known in the hunting and construction arts, and some of these systems have been applied to hunting blinds. Examples of some of the known hub and strut systems include those described in U.S. Pat. Nos. 3,810,482, 4,974,986, 5,738,129, 5,944,041, and 6,296,415. 
   Hubs known to the art generally include guiding or locking channels that position the struts at specific angles. 
   Similarly, a number of ball and socket positioning arms are known and used in a number of technical areas. Examples of some of the known ball and socket arms include those described in U.S. Pat. Nos. 5,845,885, 6,220,556, 2,560,556, 2,710,609, and 4,491,435. 
   Positioning arms known in the art generally employ a split or bifurcated arm design and a single adjustment mechanism for operating both socket clamps simultaneously. Products of this type are described in U.S. Pat. No. 5,845,885 to Camevali, and are sold by the RAM Mount Company of Seattle, Wash. 
   Although the known devices have some utility for their intended purposes, a need still exists in the art for a versatile kit and system of independently adjustable masking panels, which kit and system is adaptable for multiple outdoor concealment uses. A versatile concealment kit and system is needed, which could be used on more than one type of outdoor observation platform, in order to provide more versatility and flexibility than that encountered with the known art. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to provide a kit, system and apparatus for use in concealing a hunter or naturalist in an outdoor environment, to inhibit detection of the user by game animals and/or other wildlife. 
   The present invention, in a first embodiment thereof, provides a kit and system for providing concealment to a user, including one or more shield members employing a camouflage covering, designed to blend in to a natural environment, and related support structure. Each shield member is independently adjustable, allowing a user thereof to position and arrange it to obscure or block an outside view of the user. One or more shield members can be attached to an outdoor observation structure selected from any number of alternative outdoor hunting or observation platforms. Non-limiting examples of observation structures with which the apparatus and system hereof is usable include boats, tree stands, ladder stands, ground enclosures, and hunting chairs. 
   A kit and system according to the first embodiment hereof includes a masking panel, a panel support frame including a hub and strut tensioning apparatus, an adjustable mounting arm, and one or more mounting supports. 
   The masking panel employs a camouflage design pattern for concealment, and may be provided with a three-dimensional structure, including cut away and/or add-on portions configured to simulate leaves, twigs, moss, and/or other nature effects. Three-dimensional camouflage provides for effective concealment, because it not only breaks up the outline shape of the panel structure, but it also provides a high effective level of outward visibility from the vantage point of a user located behind the panel. Multiple camouflage designs could be created as interchangeable fabric covers for the shield members, to provide seasonally appropriate concealment. The fabric cover is temporarily attached to the panel support frame, and is removable therefrom, so that a desired camouflage pattern can be quickly applied or changed. 
   Various panel shapes may be provided, in order to accommodate any number of concealment needs. A square panel provides for a simple and effective design, though any polygonal shape would suffice. For whichever shape is chosen, a strip of strong, flexible material extends around the perimeter, and this strip may be formed from a woven strap material. This perimeter strip is attached to the masking panel fabric. Each corner of the panel is provided with a pocket for receiving an end of a post of the panel support frame component of the system. These pockets may be sewn, riveted or otherwise fastened to the strap material at the perimeter of the panel. 
   During use and when in the deployed position thereof (shown in  FIG. 1 ), the fabric masking panel of the system is attached to and supported by a panel support frame, including a hub and strut apparatus. The panel support frame used in the present invention is somewhat similar to the type of panel support frame used in a folding umbrella, but with fewer support struts used. A strut is provided corresponding to each corner of the panel, and all of these struts are pivotally attached to a central hub. The embodiment shown in the drawings uses four struts. The length of a strut should be slightly greater than the straight-line distance from the hub location to the corresponding corner of the panel fabric. In this arrangement the struts flex outwardly into a mild bow shape, and provide tension to the panel fabric, when the panel support frame is in its open, deployed position. 
   A central hub is provided to interconnect the struts, and to provide structure for attaching the struts to an end of the connecting arm. Hubs are available in a variety of designs. A first embodiment of a suitable hub is made of molded metal, or of a strong plastic or elastomer. The hub according to the first embodiment has a modified cylindrical or block shape, with a plurality of specific channel cutouts formed therein, extending radially outwardly from a central portion of the hub. A channel cutout is provided to accommodate each strut. The channel cutouts are cut into a surface of the hub intended to face outwardly during use, and extend radially out through a side wall of the hub. The strut may attach directly to the hub by way of a pin, or an end cap flexibly attached to the hub may receive an end of a strut. A hub with channels forces the struts to extend out at a specific or predefined orientation in the deployed support structure. 
   An alternative design for the hub eliminates the channels by employing a flat, circular metal plate or similar element, rather than a molded cylindrical element. Such a hub uses a braided metal cable woven through holes in the hub and in the strut ends or end caps, to allow the struts to extend out at non-predefined radial angles. This simplified design also reduces manufacturing costs, because drilling the attachment holes is less costly than molding the channels. Furthermore, this hub design provides for a greater flexibility in panel design. As a result of not being constricted to predefined angles, the same hub and strut support apparatus can be used with fabric panels of varying shapes. 
   The concealment system hereof is capable of being used in connection with virtually any outdoor observation platform. Such a platform includes, but is not limited to a boat, ground enclosure, tree stand, ladder stand, or hunting chair. A ball mount is attached to the platform to be concealed by the panel, or may be separately attached to an adjacent support substrate, such as, e.g., a tree on which the platform is mounted. The ball mount can be attached by any suitable attachment mechanism. Screw holes may be provided at the base of the ball mount to facilitate attachment. The ball mount could be a solid piece of molded plastic, or alternatively, it could include a metal ball head integrally formed with a supportive neck and attachment structure. Alternatively, the ball mount could contain a threaded auger-type mounting stud, or could be attached to a screw-in type tree step. No matter which hub design is employed, a ball mount is attached to the hub on a surface opposite the surface where the struts are attached. 
   The kit and system hereof also includes a positioning arm with an independently adjustable mounting clamp at each end. The positioning arm according to one embodiment of the invention employs a bar that spans the arm from end to end. The bar may be a solid, integral unit or may include interconnected telescoping tubes. An independent, manually operated socket clamp is attached to each end of the bar. The socket clamps on the ends of the bar may be identical to one another, because a symmetric design allows for the greatest versatility and ease of use. Additionally, nearly any angle of concealment can be achieved by having this type of ball-and-socket joint on each end of the system. As each socket clamp has a separate tightening mechanism, the angle of attachment of the clamp to each ball mount can be independently adjusted. 
   The present invention also encompasses a method of concealing a user through the use of a number of independent masking panels. 
   For a more complete understanding of the present invention, the reader is referred to the following detailed description section, which should be read in conjunction with the accompanying drawings. Throughout the following detailed description and in the drawings, like numbers refer to like parts. 
   The present invention is not limited to its application to the details of construction and to the dispositions of the components set forth in the following description or illustrated in the drawings. The present invention is capable of other embodiments and of being practiced and carried out in various ways. In addition, it is to be understood that the phraseology and terminology employed herein are for the purposes of illustration and example, and should not be regarded as limiting. 
   As such, those skilled in the art will appreciate that the concepts upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  is a perspective view of a tree stand having a camouflage cover system hereof installed thereon, with plurality of shield members attached to the tree stand according to a first illustrative embodiment of the present invention, and in which part of the blind panels are cut away to show a related support structure; 
       FIG. 1B  pictorially illustrates a sequence of steps which can be followed in installing a shield member according to the illustrative embodiment on a tree stand; 
       FIG. 1C  is a perspective outline view showing a hunter seated on a tree stand and being partially masked by a shield member; 
       FIG. 2A  is a perspective view of an inside surface of a shield member according to the first embodiment; 
       FIG. 2B  is a perspective view similar to  FIG. 2A  with a fabric panel removed, showing only the panel support frame for the shield member; 
       FIG. 3A  is a detail plan view of an inside corner surface of the shield member of  FIG. 2A , showing perimeter webbing and a pocket; 
       FIG. 3B  is a detail perspective view of an exterior surface of the shield member of  FIGS. 1-2A ; 
       FIG. 4  is an exploded perspective view of the panel support frame of  FIG. 2B , showing the hub and strut structure thereof with the struts thereof shown partially cut away; 
       FIG. 5  is a side plan detail view of the assembled panel support frame of  FIG. 2B , showing an outwardly-facing side thereof in a deployed configuration and with the struts thereof shown partially cut away; 
       FIG. 6  is a detail perspective view of a strut stabilizer which is a component part of the panel support frame of  FIG. 4 ; 
       FIG. 7  is a perspective view of an alternative hub and strut support structure usable with a second embodiment of the present invention, with the struts thereof shown partially cut away; 
       FIG. 8  is a perspective view of another alternative hub and strut support structure usable with a third embodiment of the present invention, with the struts thereof shown partially cut away; 
       FIG. 9  is a perspective view of still another alternative hub and strut support structure usable with a fourth embodiment of the present invention, with the struts thereof shown partially cut away; 
       FIG. 10A  is a perspective detail view of a ball mount kit and a positioning arm according to the present invention; 
       FIG. 10B  is an exploded perspective detail view, partially cut away, of the ball mount and one end of the positioning arm of  FIG. 10A ; 
       FIGS. 10C-10D  are alternative environmental views showing installation of the ball mount of  FIG. 10A  on a tree stand; 
       FIG. 11  is a perspective view of boat having a plurality of blind shield members attached thereto, in an alternative application of the masking system hereof. 
   

   DETAILED DESCRIPTION 
   Overview 
     FIG. 1  illustrates a tree stand  11 , as one example of an observation platform on which a concealment apparatus  10 , according to the present invention, can be mounted. The tree stand  11 , per se, does not constitute part of the present invention, but rather, provides a substrate on which the system and apparatus  10  hereof may be mounted. The masking system and apparatus  10  hereof is particularly adapted for use by hunters, naturalists and photographers in combination with an outdoor observation station such as, for example, a tree stand  11 , a ladder stand, a boat, a hunting chair, or a similar observation stand. Alternatively, the apparatus may be mounted to a tree, to provide a temporary blind. 
   A pair of identical, adjustably positionable concealment apparatus  10 ,  10 , according to a first illustrative embodiment of the present invention, are shown attached to the tree stand  11  in the drawing. As shown in  FIGS. 1-2B , in a fully deployed configuration thereof, the masking system and apparatus  10  according to the selected embodiment includes a masking assembly  15 , a positioning arm  30 , and a ball mount  24 , which is provided for attaching to a substrate and for supporting the shield member via the positioning arm. The masking assembly  15 , in turn, includes a panel support frame  40 , and a masking panel (shield member)  20  removably attached to the panel support frame. The positioning arm  30  is provided for placement extending between the ball mount and a hub portion of the masking assembly  15 . 
   The system hereof includes, at a minimum, at least one adjustably positionable concealment apparatus  10 . It will be understood, however, that a user is not limited to using a single adjustably positionable concealment apparatus  10  with a tree stand or other hunting platform, but that a user may choose to use two, three, four or more independently positionable concealment apparatus  10  together, in a coordinated fashion, to shield the user from view from a plurality of angles or directions. 
   Shield Member 
   As noted above, the masking assembly  15  includes both the masking panel  20  and the panel support frame  40 , which is provided for supportively holding the masking panel. Referring now to  FIGS. 2A ,  2 B, and  3 A, it will be seen that the masking panel (shield member)  20  is cooperatively supported by and overlies the panel support frame  40 . The masking panel  20  provides the actual concealment by being positioned in the line of sight extending between the subject being observed and the user. The masking panel  20  includes a main panel portion  22 , which is formed of a flexible fabric or sheet material having a camouflage pattern on the outwardly facing side. The illustrated embodiment of the masking panel  20  employs three-dimensional camouflage that includes an optional inner screen or mesh layer  25 , and an outer camouflage sheet  26 , which is stitched, removably fastened, or otherwise operatively connected to the mesh layer  25 . Optionally, each of the inner mesh layer  25  and the outer camouflage sheet may be imprinted with a camouflage pattern thereon. 
   A pattern of incisions  27  and holes  28  is cut into the camouflage sheet  26 , so that as shown in  FIG. 3B , cutout elements  29  of the fabric may dangle off of the outer surface of the panel, to mimic a natural leafy effect. The incisions  27  and/or holes  28  also allow wind to pass easily through the masking panel  20 , so that the panel does not act like a sail or kite to provide significant wind resistance. 
   The illustrated embodiment shows a substantially rectangular masking panel  20 . However, it is within the scope of the invention to use a panel  20  having a circular or oval shape, a crescent shape, a regular polygonal shape, or any other desired shape. A high-strength, flat reinforcing strip  32  of material may be affixed to the inner mesh layer  25  along its outer edge. Such a material includes, but is not limited to nylon or other woven polymeric webbing. The reinforcing strip  32 , where used, may be sewn to the camouflage sheet  26  or inner mesh layer  25 , or may be removably attached to the sheet  26  or to the inner mesh layer using any suitable connector  34  such as ties, snaps, or a hook-and-loop fastener such as VELCRO™, so that different, possibly seasonal camouflage sheets may be attached and interchanged as needed. In the depicted embodiment, the reinforcing strip  32  at the perimeter of the masking panel  20  has pockets  36  affixed thereto, provided near each corner and aligned with a line extending between diagonally opposed corners. The pockets  36  may include reinforced support sockets. In the deployed position of the concealment apparatus  10 , a significant amount of force is exerted on the masking panel  20  by the panel support frame  40 . Accordingly, the pockets  36  may include rigid or semi-rigid plastic or metal sleeves, and rivets  38  may be used, if desired, to attach each of the pockets  36  to the reinforcing strip  32  at the corners of the masking panel  20 . 
   The Panel Support Frame 
   While a number of different embodiments of support frames  40  are disclosed, the common elements of all embodiments include a central hub  42 , a plurality of struts  44 , which are each pivotally attached to the hub, and extend outwardly therefrom, and a ball mount  43 , which is affixed to the hub  42 . The embodiments differ in the hub construction. One embodiment includes a generally disc-shaped or cylindrical hub  74 , while another embodiment includes a circular hub plate  45 . The difference between the two embodiments is that in the first embodiment, the hub  74  may include guide channels as described in detail below. 
   Any suitable hub structure which is effective in a field situation could be used, such as, e.g. the hub structure described in U.S. Pat. No. 3,810,482, the disclosure of which is incorporated by reference. The hub disclosed in this reference would be modified, however, to fixedly and centrally attach a ball member to the side of the hub opposite the struts, in place of the handle described in the reference. 
   In the depicted embodiments, the hub  42  or  74  also includes a central ball  43  as a rigidly attached component thereof. The ball  43  faces inwardly in the deployed configuration of the panel support frame  40 . The ball  43  is provided for insertion into a first socket clamp of the positioning arm  30 , as will be subsequently described. 
   In the illustrated embodiment, four struts  44  of equal length are provided for each hub  42 , 74 . However, it is within the scope of this invention to provide a hub having a fewer or greater number of struts, or to include struts of different lengths. The number of struts  44  should correspond to the number of corners. The shape of the masking panel  20  and the position of the corner pockets  36  determine the radial angle at which each strut  44  extends out from the hub  42 . 
   The struts  44  can be made from any strong, semi-flexible fiberglass, plastic, metal, or composite material. In the depicted embodiment, each distal strut end  46  is covered with a plastic or elastomeric end cap to protect the pocket  36 . 
   While the size of the masking panel  20  is not critical, the relationship between the distance from one corner to the diagonally opposed corner, compared to the distance between the ends of two diagonally opposed frame strut ends  46  is important. When the hub  42  is positioned in the center of the masking panel  20 , and the struts are unbowed, the distal ends  46  of the struts extend out past each corner pocket  36 . 
   A sequence of steps which may be followed in unfolding, assembling and installing a masking assembly  15  on a tree stand is illustrated pictorially in  FIG. 1B . The masking assembly  15  is shown in a folded or collapsed configuration in FIG.  1 B(A), and the subsequent unfolding, deployment and mounting thereof is shown in FIGS.  1 B(B)- 1 B(F). In order to connect the masking panel  20  to the panel support frame  40 , the frame hub  42  must be raised off of the plane of the masking panel  20 . This allows the struts  44  of the frame to angle downward toward the corner pockets  36 . After inserting each strut end  46  into its corresponding corner pocket  36 , the frame  40  and panel  20  take the form of a modified 4-faced pyramid with the masking panel  20  as the base. To deploy the masking panel  20 , the frame hub  42 ,  74  needs to be pushed outwardly, or toward the plane of the panel, while the strut ends  46  are simultaneously pulled inwardly, in an opposite direction of the hub movement. When sufficient pressure is applied, this will stretch the material of the panel  20  and will move the outer ends of the struts  44  in past the hub  42 ,  74 , causing the masking panel  20  to snap to an inverted pyramidal shape, or to a configuration somewhat resembling an open umbrella, as shown in  FIGS. 1A ,  1 C, and  2 A. The struts  44  will then be bowed outwardly, and thereby provide tension to keep the masking panel  20  taut on the panel support frame. 
   Traditional Hub with Additional Strut Stabilizing Insert 
   A detailed view of a first illustrative embodiment of the support frame  40 ,  72  is depicted in  FIGS. 4 and 5 . As described above, the support frame  40 ,  72  includes a central hub  74  with struts  76  extending therefrom. The central hub  74  is made of a hard molded material such as plastic or metal. Four struts  76  extend out from the hub  74 . Each strut  76  has a proximal end, for placement near the hub, and an outer or distal end. A proximal end cap  164  covers the proximal end, and a distal end cap  166  covers the distal end. The proximal end caps  164  include opposed pins  110  extending outwardly from side portions thereof, and a protruding ridge or stop member  114 . The pins  110  engage the hub and allow the struts to pivotally swing while the protruding ridge  114  acts as a stop member to limit the allowed range of travel in the swinging motion. 
   The hub  74  includes a main hub body  75  which is substantially cylindrical in exterior shape, with opposite first and second surfaces and a sidewall extending therearound. Guide channels  100  are formed in the second surface of the main hub body, to respectively accommodate the struts  76 , and these guide channels extend radially out to the sidewall. A plurality of strut insertion through holes  98  are formed through the main hub body  75  extending axially from the first surface to the guide channels  100 , to facilitate the connection of the struts  76 . These strut insertion holes  98  communicate with shallow pin guide channels  99  formed in the first surface of the main hub body, that receive and engage the end cap pins  110 . A braking surface  118  that engages the protruding ridge  114  is also formed in the main hub body for each of the strut insertion holes  98 . A center hole  120 , which may have female threads formed therein, is cut through the center of the main hub body  75 . 
   A ball mount  43  is fixedly attached to an outer end of a threaded stud  106 . The stud  106  passes through a washer  80 , a flat hub cap  104 , a strut stabilizer  121 , and the threaded center hole  120 , and is secured with a nut  105  on the second surface of the hub. 
   The strut stabilizer  121  limits movement of the struts  76  in the hub insertion holes  98 , and also applies pressure to the end cap pins  110 , thereby stabilizing the struts  76 . The strut stabilizer  121  includes a circular plate  122  formed of molded plastic that has a plurality of integrally formed pin-engaging protrusions  124  on one side thereof. There are two protrusions  124  for each strut, with one protrusion  124  provided for each pin  110 . The protrusions  124  are molded to interlock with the pin guides  99  of each strut attachment hole  98 , to contact the pins  110 , and to limit movement of the pins in the hub assembly. The hub cap  104  acts as a large reinforcing washer and evenly distributes the pressure of the nut to the strut stabilizer  121 . 
   Plate and Cable Based Hub 
     FIG. 7  demonstrates another embodiment of a simplified hub  42  that includes a circular metal hub plate  45  having a top and bottom surface. There is a hole  52  in the center of the hub plate  45 , as well as pairs of spaced-apart perimeter holes  54  disposed about the perimeter thereof. There will be a pair of perimeter holes  54  for each strut  44 . Each pair of perimeter holes  54  is spaced an equal distance from the next pair, and the distance between two holes that form a pair is slightly greater than the width of a strut  44 . Each strut  44  has an attachment hole  56  formed through one end thereof, transverse to the longitudinal axis of the strut, for attaching it to the hub  42  with cabling  58 . A spherical metal ball, similar to the ball  43  shown in the embodiment of  FIG. 4 , is rigidly attached to the metal plate of the hub  42 , on a side thereof opposite the struts  44 . The ball may be attached by welding or other suitable method. 
   A strong braided metal cable  58  is fed through the center hole  52  from the top surface to the bottom surface. Next it is fed through a perimeter hole from the bottom surface to the top surface. The cable  58  then passes through the attachment hole  56  in the end of one of the struts  44 . The cable  58  then passes through the next adjacent perimeter hole from the top surface to the bottom surface. This sequence is repeated until the desired number of struts  44  is attached. The cable  58  is then formed into a loop, by passing it back through the center hole  52  and fastening it to itself with a fastener  60 . 
   Plate and Cable Based Hub Including Crimped Endcaps 
     FIG. 8  demonstrates a third embodiment of a simplified hub  142  that includes a circular metal plate  141  having a top and bottom surface. This third embodiment is again provided with a plurality of struts  144 , and in this embodiment, each strut  144  is fitted with a metal endcap  162  that has an open strut receiving end, and a crimped end that fixedly receives an attachment cable  158 . Unlike the previous embodiment that used a single loop of cabling, this embodiment employs multiple strands of cabling. In this embodiment, the hub plate  141  includes a single cabling hole  154  corresponding to each strut  144 . In the disclosed embodiment there are four struts  144 , four cabling holes  154  in the hub plate  141 , and two strands of cable  158 . Each end of a strand strong braided metal cable  158  respectively passes from the bottom surface through two adjacent cabling holes  154  to the top surface. An endcap  162  is crimped onto each cable end. The hub  142  includes a central hole that receives a stud  145  with a ball mount  143  fixedly attached thereon. The stud  145  is secured with a washer and nut combination. 
   Plate and Cable Based Hub Including Threaded Endcaps 
     FIG. 9  demonstrates a fourth embodiment of a simplified hub  242  that includes a circular metal plate  241  having a top and bottom surface. Each strut  244  is fitted with a metal endcap  262 . Each endcap  262  includes an attachment hole  264  formed transverse to the longitudinal axis of the strut  244 , for attaching it to the hub  242  with cabling  258 . The hub plate  241  includes a single cabling hole  254  corresponding to each strut  244 . In the disclosed embodiment there are four struts  244  and four cabling holes  254 . A strong braided metal cable  258  passes from bottom surface through a cabling hole  254  to the top surface. Next the cable  258  passes through an end cap attachment hole  264 , and then returns back through the same cabling hole  258  to emerge at the bottom surface. This process is repeated for each strut  244  such that the cable  258  returns to the bottom surface where it is fastened to itself with a crimped fastener  260 . The hub  242  includes a central hole that receives a stud  245  with a ball mount  243  fixedly attached thereon. The stud  245  is secured to the hub plate  241  with a washer and nut combination. 
   Ball Mount 
   Referring now to  FIG. 10 , a particular embodiment of a ball mount  170  is shown, along with an end portion of a positioning arm  30 . The ball mount  170  is provided for attachment to a tree, tree stand, or other support. The ball mount  170  can be formed from a single piece of molded plastic or metal, or alternatively, can comprise a ball  174 , a threaded stud  176  formed integrally with the ball, and a base  178 . The size of the ball  174  may vary, as desired, but may be in a range from about one-half inch to 1.5 inches in diameter, for example. The base  178  of the ball mount should include holes  180  to facilitate the attachment of the ball mount to a particular platform  12 . In some applications, simple screws or nuts and bolts may be sufficient to effectuate the attachment. In the illustrated embodiment, a U-bolt  175  may be employed to attach a ball mount  170  to a tree stand frame or similar support. 
   Positioning Arm 
   The positioning arm  30  includes a socket clamp  190 ,  192  at each end thereof, respectively, as shown in  FIG. 1 . The socket clamps  190 ,  192  at each end of the positioning arm  30  are substantially identical to one another, so only a single socket clamp  190  is shown in detail in  FIG. 10 . As best seen in  FIG. 10 , and as exemplified by socket clamp  190  in the drawing, each socket clamp includes an integral gripping element  194  and an adjustably movable gripping element  196  which is pivotally attached to the integral gripping element. 
   Each gripping element  194 ,  196  includes a base portion  198  and a concave, roughly hemispheric receiving section  200 . Depending on the composition of the ball mounts  43 ,  74 , it might be advantageous to coat the receiving sections  200  of the gripping elements in rubber, plastisol coating or similar material, to increase the friction of the grip. This coating, however, is not required in the practice of the present invention. 
   The integral gripping element  194  is formed integrally with the bar section of the arm, and the adjustably movable gripping element  196  is formed separately from the bar section, and is pivotally attached to the integral gripping element  194  by a rivet or similar fastener. The gripping elements  194 ,  196  can be made from metal or plastic or some combination thereof. Each of the gripping elements  194 ,  196  has a through hole  199  formed respectively therein to accommodate a bolt  202 . 
   A spring  210  is provided extending between the gripping elements  194 ,  196  to bias them in an opening direction, and a handle  204 , having a threaded nut embedded therein, is provided to attach to the bolt  202  and to allow manual tightening of the clamp  190 . The handle  204  is substantially T-shaped and includes a pair of opposed, outwardly extending gripping sections  206 ,  208  to allow grasping by a user to easily turn the handle. The bolt  202  is fed through the through holes  199  of the gripping elements, and also passes through the center of the spring  210 . Optionally, a wing nut (not shown) could be substituted in place of the handle  204 . 
   As the handle  204  is loosened, the spring  210  around the bolt  202  forces the receiving sections  200  of the two gripping elements  194 ,  196  away from each other, in order to receive a ball mount  43 ,  174  therebetween. Similarly, once the ball mount  43 ,  174  has been received, the handle  204  is tightened to lock the socket clamp  190  on to the ball mount  43 ,  174 , in order to temporarily fix the angle of attachment thereof. 
   Positioning Arm 
   The positioning arm  30  can be formed as a unitary span  222  of strong rigid material. Steel tubing or extruded aluminum tubing provides a good combination of strength and weight considerations. The positioning arm  30  may, alternatively, include two tubes arranged in telescoping relation, with a thumbscrew or similar fastener to lock the relative positions of the tubes. The illustrated embodiment shows an arm  220  where the integral gripping elements  194  of each socket clamp  190 ,  192  is permanently attached to respective ends of the arm span  222  by welding. Other mechanisms of attachment such as a rivet, or a screw mount could alternatively be used. 
     FIGS. 11A-11C  illustrate an application of the system hereof to a boat  300 .  FIG. 11A  shows four concealment apparatus  10  attached to a first side of the boat  300 .  FIG. 11B  shows four concealment apparatus  10  attached to a second side of the boat  300  as an alternative application.  FIG. 11C  shows the boat  300  as it would appear without the concealment apparatus installed thereon. 
   Method 
   The present invention also provides a method of concealment. One non-limiting example of a method which may be used for concealing a hunter or other user is as follows: 
   Step 1. Provide a tree stand  12  or, alternatively, provide any other of many possible observation stations, as previously noted. 
   Step 2. Attach a ball mount  170  to a solid portion of the observation station such as to a tubular frame member of the tree stand  12 . This may be accomplished by placing a U-bolt  82  around the frame member and then passing the threaded ends of the U-bolt through the mounting holes  180  on the base  178  of the ball mount  170 . 
   Step 3. Prepare a masking panel  20  for deployment by choosing a suitable camouflage covering  26  and attaching it to a perimeter webbing  32  with ties  34 . 
   Step 4. Attach the frame  40  to the masking panel  20  by inserting each strut end  46  into its own panel corner pocket  36 . 
   Step 5. Deploy panel  20  by pressing the hub  42  toward the plane of the panel fabric  26  while simultaneously pulling one or more strut ends  46  in an opposite direction of the pushing motion. 
   Step 6. Attach the deployed panel  20  to the positioning arm  30  by loosening the handle  204  of the second socket clamp  192  and allowing the biasing spring  210  to spread the gripping elements  194 ,  196 , position the hub ball  43  between the receiving sections  200  of the gripping elements  194 ,  196 , angling the deployed panel  20  to a desired angle, and tightening the hand screw  204  so that the receiving sections  200  firmly grip the hub ball  43 . 
   Step 7. Attach the positioning arm  30  to the ball mount  170  by loosening the handle  204  of the first socket clamp  190  and allowing the spring  210  to spread the gripping elements  194 ,  196 , position the ball  174  between the receiving sections  200  of the gripping elements  194 ,  196 , adjust the positioning arm  30  to a desired angle, and tighten the handle  204  so that the receiving sections  200  firmly grip the ball  174 . 
   Step 8. Repeat all of the preceding steps as necessary with additional independent masking panels in order to provide a desired level of concealment. 
   Although the present invention has been described herein with respect to a number of specific illustrative embodiments, the foregoing description is intended to illustrate, rather than to limit the invention. Those skilled in the art will realize that many modifications of the described embodiment could be made which would be operable. All such modifications, which are within the scope of the claims, are intended to be within the scope and spirit of the present invention.