Abstract:
A mobile observation stand assembly includes a platform that may be in a lowered position for transport and an elevated position for use in a desired location. The assembly includes a base supported by a wheel and axle assembly, with an articulated anterior frame and an articulated posterior frame attached to the base. The posterior and anterior frames each include a basal frame and a principal frame that are jointed by a rollover lock joint that allows for pivotal movement. A leveraging cam is attached to the posterior frame, with the cam supporting the anterior frame during repositioning of the assembly.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to the field of portable stands, and more particularly the present invention relates to an articulated observation or hunting stand that is easily transported to a desired location as preferred by the user, and that may be extended and retracted manually by one user with relative ease. 
     BACKGROUND OF THE INVENTION 
     Standard observation stands traditionally include a platform which is raised substantially from the ground and which may serve multiple purposes. Such observation stands may be used as a hiding place and surveillance platform for wildlife spectators or hunters, as a post for general observation, as a guard or supervisory tower by the police, army, or related parties, or as a platform for various other public events. 
     Multiple designs for observation stands of this type are commonly known. Such stands are typically quite complex and made of heavy materials that are difficult to assemble and cumbersome to move. Many observation stands further require manual help to move about, and can therefore be nuisances if the observation stand has to be moved in natural terrain where conventional transportation means do not exist. Moreover, many current observations stands are not freestanding, but in fact require a vertical beam or other vertical surface (such as a tree or a wall) in order to securely stand upright. 
     What is desired, then, and not found in the prior art, is a mobile observation stand that is easily transported to a desired station and that is easily repositioned between a collapsed and retracted position and an extended position in which the observation platform assembly is freestanding in a relatively high elevated position for the user or users. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an observation platform assembly that is mobile. 
     An object of the present invention is to provide an articulated observation platform assembly having a surveillance platform that may be moved between an extended and a retracted position. 
     A further object of the present invention is to provide a mobile observation platform assembly that will securely support at least one person when in an extended position. 
     An additional object of the present invention is to provide an observation platform assembly that is freestanding when in the extended position. 
     A further object of the present invention is to provide an observation platform assembly that occupies a small volume area when in a retracted position. 
     The mobile observation platform assembly according to the present invention includes a series of articulated members that allow a user to move a surveillance platform between an extended position and a retracted position. More specifically, the mobile observation platform assembly includes a base platform with an articulated posterior frame and an articulated anterior frame pivotally connected to the base platform. The posterior frame is connected to the anterior frame when the mobile observation platform assembly is in the extended position. Moreover, the surveillance platform is pivotally connected to the anterior frame so that the surveillance platform may be rotated to connect with the posterior frame when the observation stand is in the extended position. 
     The posterior frame includes a principal rear frame member and a basal rear frame member. The principal rear frame member includes two inverted L-shaped arms that are joined together by a series of horizontal support beams. The basal rear frame member includes a pair of straight vertical rods, with the straight rods being joined together by a series of substantially horizontal support beams. Additionally, the principal rear frame member and basal rear frame member both include a ladder segment having a series of rungs that allow the user of the observation stand to climb to the surveillance platform. Moreover, the surveillance platform includes a recessed cavity positioned proximate the ladder segment of principal rear frame member that allows the user easy access to the uppermost surface of the surveillance platform from this ladder segment. 
     The anterior frame includes a principal frontal frame member and a basal frontal frame member. Similar to the principal rear frame member, the principal frontal frame member includes two inverted L-shaped arms, with the L-shaped arms conventionally being joined together by at least one support beam. The basal frontal frame member includes a pair of straight vertical rods, with the straight rods also being joined together by at least one support beam and by a series of support cross braces, as discussed further herein. It should be noted that each straight rod is preferably hollow, with each straight rod being able to receive a leveling leg or foot at the lower end. Each leveling leg is slidable within the straight rod, and is locked into a position within the straight rod using a conventional pin that connects the straight rods with the respective leveling leg. Consequently, the user may adjust the position of the leveling leg within each straight rod to provide the desired support on the specific terrain associated with the location of the mobile observation stand. 
     As discussed above, both the posterior frame and the anterior frame include upper frame members and lower frame members, respectively. Each upper frame member is connected to the respective lower frame member via a pair of rollover lock joints. One rollover lock joint is connected between each inverted L-shaped arm and respective corresponding straight rod. More specifically, each rollover lock joint includes a pair of joint plates that are connected to opposing sides of each straight rod, with a pivot rod further connecting the joint plates. The rollover lock joint additionally includes a cylindrical sleeve, and the cylindrical sleeve is attached to each inverted L-shaped arm. The cylindrical sleeve is attached a short distance from the straight rod end to allow the rod to be pinned, and surrounds the pivot rod to allow each L-shaped arm to pivot about the pivot rod. Consequently, the L-shaped arm may pivot between a locked extended position and an unlocked retracted position. When in the extended position, a conventional lock pin may be inserted into the joint plates so as to prevent the movement of the respective L-shaped arm. 
     When the observation platform assembly is in the extended position, a series of cross braces may be attached between the lower frame members to reinforce the general stability of the observation platform assembly. More specifically, a pair of support cross braces are attached between the straight rod and the straight arm of the anterior lower frame member. In addition, two separate pairs of auxiliary cross braces connect the posterior lower frame member with the anterior lower frame straight rod, and the anterior lower frame member with the posterior lower frame straight rod. These cross braces therefore stabilize the observation platform assembly for the user to safely climb the ladder segment and stand or sit on the surveillance platform. 
     The observation platform assembly additionally includes a pair of leverage or lifting cams, with one lifting cam being attached to each L-shaped arm of the posterior frame member. The lifting cams provide a mechanical advantage to the present design to aid the user in repositioning the observation platform assembly between the extended position and the retracted position. Furthermore, it should be noted that in one embodiment, the L-shaped arms of the upper anterior and posterior assemblies overlap when in the extended position and are connected with conventional pins to aid in stabilizing the upper assembly. 
     These and other objects and advantages of the invention and the operation thereof will become apparent from the following detailed description of the preferred embodiment of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A mobile observation platform assembly embodying the features of the present invention is depicted in the accompanying drawings which form a portion of this disclosure and wherein: 
     FIG. 1 is a rear perspective view of the mobile observation platform assembly of the present invention, the mobile observation platform assembly being in an extended position; 
     FIG. 2 a  is a rear elevational view of the mobile observation platform assembly as illustrated in FIG. 1; 
     FIG. 2 b  is a side elevational view of the mobile observation platform assembly as illustrated in FIG. 1; 
     FIG. 3 is a rear perspective view of the mobile observation platform assembly of the present invention, the mobile observation platform assembly being in a retracted position. 
     FIG. 4 is a side elevational view of the mobile observation platform assembly as illustrated in FIG. 3; 
     FIG. 5 is a rear perspective view of the mobile observation platform assembly of the present invention, with the mobile observation platform assembly being retracted from the position illustrated in FIG. 1; 
     FIG. 6 is a side elevational view of the mobile observation platform assembly as illustrated in FIG. 5; 
     FIG. 7 is a side elevational view of the mobile observation platform assembly of the present invention, with the mobile observation platform assembly being retracted from the position illustrated in FIG. 6; 
     FIG. 8 is a side elevational view of the mobile observation platform assembly of the present invention, with the mobile observation platform assembly being retracted from the position illustrated in FIG. 7; 
     FIG. 9 is a rear perspective view of the mobile observation platform assembly of the present invention, with the mobile observation platform assembly being further retracted from the position illustrated in FIG. 7; 
     FIG. 10 is a side elevational view of the mobile observation platform assembly as illustrated in FIG. 9; 
     FIG. 11 is a rear perspective view of the mobile observation platform assembly of the present invention, the mobile observation platform assembly being further retracted from the position illustrated in FIG. 9; 
     FIG. 12 is a side elevational view of the mobile observation platform assembly as illustrated in FIG. 11; 
     FIG. 13 is a rear perspective view of the mobile observation platform assembly of the present invention, with the mobile observation platform assembly being further retracted from the position illustrated in FIG. 11; 
     FIG. 14 is a side elevational view of the mobile observation platform assembly as illustrated in FIG. 13; 
     FIG. 15 a  is an enlarged perspective view of the rollover lock joint used in the present invention, the rollover lock joint being in the extended position; and 
     FIG. 15 b  is an enlarged perspective view of the rollover lock joint used in the present invention, the rollover lock joint being in the retracted position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the figures for a better understanding of the articulated mobile observation platform assembly  10  of the present invention, it will be appreciated that the preferred embodiment of the present invention comprises a series of articulated members that allow a user to move a surveillance platform  18  between an extended position (see FIGS. 1,  2   a  and  2   b ) and a retracted position (see FIGS.  3  and  4 ). More specifically, the mobile observation platform assembly  10  includes a trailer bed or base platform  12  having a posterior side and an anterior side, with a conventional trailer hitch  13  attached to said anterior side. Moreover, an axle  14  is rotatably connected to the base platform  12  in a conventional manner, with a pair of wheels  16  attached to the two ends of the axle  14  to provide transportability of the mobile observation platform assembly  10 . The mobile observation platform assembly  10  additionally includes an articulated posterior frame  20  having one end pivotally connected to the posterior side of the base platform  12 , and an articulated anterior frame  40  having one end pivotally connected to the anterior side of the base platform  12 . The unattached end of the posterior frame  20  is joined with the unattached end of the anterior frame  40  when the mobile observation platform assembly  10  is in the extended position, as shown in FIG.  1  and discussed further herein. Moreover, the surveillance platform  18  is pivotally connected to the anterior frame  40  so that the surveillance platform  18  may be pivoted to connect with the posterior frame  20  when the observation platform assembly  10  is in the extended position, thereby providing a secure supportive surface for the user of the observation platform assembly  10 . 
     Looking specifically to FIGS. 1,  2   a , and  2   b , the posterior frame  20  includes a principal rear frame member  22  and a basal rear frame member  24 . The principal rear frame member  22  further includes two inverted L-shaped arms  26   a ,  26   b  that are joined together by several horizontal support beams or connecting braces  28 . The basal rear frame member  24  includes a pair of straight rods  30   a ,  30   b , with the straight rods  30   a ,  30   b  being joined together by a series of substantially horizontal support beams or connecting braces  32 . Additionally, the principal rear frame member  22  and basal rear frame member  24  both include a ladder segment  34  having a series of rungs  35  that allow the user of the observation platform assembly  10  to climb to the surveillance platform  18 . Moreover, the surveillance platform  18  includes a recessed cavity  19  positioned proximate the ladder segment  34  of principal rear frame member  22  that allows the user easy access to the uppermost surface of the surveillance platform  18  from this ladder segment  34 . The recessed cavity  19  may be positioned within the platform  18  as desired by the manufacturer to provide the desired access to the platform  18  by the user. 
     Continuing to view FIGS. 1,  2   a , and  2   b , the anterior frame  40  includes a principal frontal frame member  42  and a basal frontal frame member  44 . Similar to the principal rear frame member  22 , the principal frontal frame member  42  includes two inverted L-shaped arms  46   a ,  46   b , with the L-shaped arms  46   a ,  46   b  conventionally being joined together by at least one support beam  48 . The basal frontal frame member  44  includes a pair of straight rods  50   a ,  50   b , with the straight arms  50   a ,  50   b  also being joined by a series of support cross braces  52 , as discussed further herein. In the extended position, the L-shaped arms  46   a ,  46   b  of the principal frontal frame member  42  are connected with the L-shaped arms  26   a ,  26   b  of the principal rear frame member  22  via a series of pins  62 . This connection further reinforces the assembly of the invention. 
     It should be noted that each straight rod  30   a ,  30   b ,  50   a , and  50   b  is preferably hollow, with each straight rod  30   a ,  30   b ,  50   a , and  50   b  being able to receive a leveling leg or foot  51 . Each leveling leg  51  is slidable within the straight rod  30   a ,  30   b ,  50   a , and  50   b , and is locked into a position within the straight rod  30   a ,  30   b ,  50   a , and  50   b  using a conventional pin  53  that connects the straight rods  30   a ,  30   b ,  50   a , and  50   b  with the respective leveling leg  51  through a series of sequential holes. Consequently, the user may adjust the position of the leveling leg  51  within each straight rod  30   a ,  30   b ,  50   a , and  50   b  to provide the desired support on the specific terrain associated with the location of the mobile observation platform assembly  10 . 
     As discussed above, both the posterior frame  20  and the anterior frame  40  include upper frame members  22 ,  42  and lower frame members  24 ,  44 , respectively. Each upper frame member  22 ,  42  is connected to the respective lower frame member  24 ,  44  via a pair of rollover lock joints  60 , as illustrated in detail in the enlarged views of FIGS. 15 a  and  15   b . In the preferred embodiment, one rollover lock joint  60  is connected between each inverted L-shaped arm  26   a ,  26   b ,  46   a , and  46   b  and respective corresponding straight rod  30   a ,  30   b    50   a , and  50   b  . More specifically, each rollover lock joint  60  includes a pair of joint plates  61   a ,  61   b  that are connected to opposing sides of each straight rod  30   a ,  30   b    50   a , and  50   b . In addition, a pivot rod  64  further connects the joint plates  61   a ,  61   b . The rollover lock joint  60  also includes a cylindrical sleeve  66 , and the cylindrical sleeve  66  is attached to the lower end of each inverted L-shaped arm  26   a ,  26   b ,  46   a , and  46   b . The cylindrical sleeve  66  surrounds the pivot rod  64  to allow each L-shaped arm  26   a ,  26   b ,  46   a , and  46   b  to pivot about the pivot rod  64 . Consequently, the L-shaped arm  26   a ,  26   b ,  46   a , and  46   b  may pivot between a locked extended position (see FIG. 15 a ) and an unlocked retracted position (see FIG. 15 b ). When in the locked position, the lock pin  62  may be inserted through the joint plates  61   a ,  61   b  so as to prevent the movement of the respective L-shaped arm  26   a ,  26   b ,  46   a , and  46   b.    
     When the observation platform assembly  10  is in the extended position, a series of cross braces may be attached between the lower frame members  24 ,  44  to reinforce the general stability to the observation platform assembly  10 . More specifically, a pair of support cross braces  52  are attached between straight rod  50   a  and straight rod  50   b  of the anterior lower frame member  44 . In addition, two separate pairs of cross braces (auxiliary posterior cross braces  54  and auxiliary anterior cross braces  55 ) connect the posterior lower frame member  24  with the anterior lower frame member  44 . These support and auxiliary cross braces  52 ,  54 , and  55  therefore strengthen and stabilize the observation platform assembly  10  for the user to safely climb the ladder segment  34  and walk or sit on the surveillance platform  18 . 
     The observation platform assembly  10  additionally includes a pair of leverage or lifting cams  58 , with one lifting cam  58  being attached to each L-shaped arm  26   a ,  26   b  of the posterior frame member  22 . The lifting cams  58 , as incorporated into the present design, provide a mechanical advantage to aid the user in repositioning the observation platform assembly  10  between the extended position and the retracted position. The use of the lifting cams  58  will be discussed further herein. 
     Looking now to FIGS. 1-13 b , we will describe the process of repositioning the observation platform assembly  10 . For clarity purposes, the process that will be discussed in detail will illustrate the repositioning of the observation platform assembly  10  from the extended position (see FIGS. 1,  2   a , and  2   b ) to the retracted position (see FIGS.  3  and  4 ). It is important to note at the outset that this repositioning process may simply be substantially reversed to reposition the observation platform assembly  10  from the retracted position to the extended position. Looking specifically to FIGS. 2 a  and  2   b , the observation platform assembly  10  is shown in the extended position for a user to be elevated on the surveillance platform  18 . As illustrated, one end of each auxiliary cross brace  54 ,  55  is permanently interconnected to a respective rotating joint  59  attached to the trailer base  12 , while the opposing end of each auxiliary cross brace  54 ,  55  is detachably connected to one of the straight rods  30   a ,  30   b ,  50   a ,  50   b  of the lower frame members  24 ,  44 . To begin the repositioning process, the user verifies that the trailer hitch  13  is secured to a stable item, such as a vehicle (not illustrated). Once the trailer bed  12  is secure, the pins  62  that join L-shaped arms  26   a ,  26   b  with L-shaped arms  46   a ,  46   b  are removed, and the leveling legs  51  are retracted into the straight rods  30   a ,  30   b ,  50   a ,  50   b . Next, the anterior cross braces  52  are disconnected from straight rods  50   a ,  50   b  and folded down across and onto the trailer base  12 . The auxiliary posterior cross braces  54  are then disconnected from the respective posterior straight rods  30   a ,  30   b  of the basal rear frame member  24  such that the posterior frame  20  may be pivotally moved toward the anterior frame  40 . The user stands on base  12  and removes lock pins  65  from posterior rollover lock joints  60 . The user grasps the lower horizontal support beam  28  and pulls it toward the anterior frame  40 , controlling the descent of the platform  18  and posterior frame  20 . 
     As the posterior frame  20  moves toward the anterior frame  40 , the L-shaped arms  26   a ,  26   b  of the principal rear frame members  22  will pivot about the posterior rollover lock joint  60  (see FIGS.  5  and  6 ). As a result of the movement about the rollover lock joint  60 , the L-shaped ends  26   a ,  26   b  of the principal rear frame member  22  will move toward the base or ground surface while the lower extremity of the straight rods  30   a ,  30   b  of the basal rear frame member  24  are elevated. The auxiliary anterior cross braces  55  preferably remain connected to the anterior frame  40 . The posterior frame  20  continues to collapse and move through the anterior frame  40  until the lifting cams  58  on upper posterior frame  26   a ,  26   b  contact the lower anterior straight rods  50   a ,  50   b  (as illustrated in FIG.  6 ). 
     Next, quick release pins  57  are removed from the front support cross braces  55  that connect to straight rods  50   a ,  50   b . The front support cross braces  55  are then folded down onto the trailer frame  12 . Looking to FIGS. 1,  7 , and  8 , the user elevates the posterior frame  20  by manually lifting up on the cross brace  28  proximate the rollover lock joints  60 , which further regulates the descent of both the posterior frame  20  as well as the anterior frame  40  with respect to the lifting cams  58 . The posterior side  20  will continue to rise as the anterior frame  40  pivots downward, with the lifting cams  58  of the posterior frame  20  engaging the anterior frame  40  during the decent of the anterior frame  40 . Finally, as the L-shaped arms  26   a ,  26   b  of the posterior frame  20  engage the ground surface (see FIGS.  9  through  12 ), the anterior side  40  will rest significantly on the lifting cams  58 . 
     As the principal rear frame members  22  of the posterior frame  20  rests on the ground surface, the user will manually move the principal rear frame members  22  about four feet away from the trailer frame  12 . Such movement will cause the lifting cams  58  to move away from the straight rods  50   a ,  50   b  of the anterior frame  40 . The locking pins  65  of the rollover lock joints  60  of the anterior frame  40  are then removed, and the basal frontal frame member  44  drops downward (see FIGS.  11  and  12 ), and the surveillance platform  18  will come to rest against the posterior frame  20 . The disconnect pin  64  is removed from the principal front frame member  44  to separate the surveillance platform  18  from the anterior frame  40 , and the basal frontal frame member  44  of the anterior frame  40  comes to rest on the trailer frame  12 . The principal frontal frame member  42  is then pivoted via the rollover lock joints  60  to also fold down onto the trailer frame  12 . 
     Once the anterior frame  40  is laid onto the trailer frame  12 , the principal rear frame member  22  and the basal rear frame member  24  of the posterior frame  20  are folded together about the rollover lock joint  60  of the posterior frame  20 . The folded posterior frame  20  is then pivoted about the pivot points  59  connected to the trailer frame  12  to bring the posterior frame  20  to rest upon the trailer frame  12  as well (see FIG.  4 ). 
     It should further be noted that the observation platform assembly  10 , when elevated, may reach a height of over fourteen feet. However, when retracted, the observation platform assembly  10  only rises approximately four feet off of the ground surface. Moreover, fixed arms  26   a ,  26   b ,  46   a , and  46   b  could be removable, or folded down, to further reduce the collapsed height to less than two feet. The observation platform assembly  10  may then act as a conventional trailer to support and move heavy cargo. 
     In conclusion, the observation platform assembly  10  is designed such that an ordinary user may reposition the heavy observation platform assembly  10  alone, and a knowledgeable user can reposition the observation platform assembly  10  to extend or retract quickly within approximately five minutes. Furthermore, it should be noted that the observation platform assembly  10  additionally includes various means for protecting the user when in the elevated position. First, a chair  17  (see FIG. 1) is easily attachable to the surveillance platform  18  to allow the desired comfort and safety of the user when on the surveillance platform  18 . Second, the L-shaped arms  26   a ,  26   b ,  46   a ,  46   b  and the support beams  28 ,  48  act as security rails for the user to keep the user on the surveillance platform  18 . 
     Variations of the preferred embodiment of the observation platform assembly  10  may also be designed. For example, although not shown in the figures, the observation platform assembly  10  may include one or more reinforcement plates that are slidably positioned within the base platform  12  or pivotally affixed to the base platform  12 . The reinforcement plates could be affixed to any side of the base platform  12  such that they would act as ramps to aid the user in positioning heavy machinery (such as an ATV) on the base platform  12 . Furthermore, these reinforcement plates could also provide a stable flooring for the user to be able to easily walk on the base platform  12 . 
     Thus, although there have been described particular embodiments of the present invention of a new and useful MOBILE OBSERVATION PLATFORM ASSEMBLY, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.