Abstract:
An expandable trailer for transporting and using exercise equipment on the expanded trailer platform, comprising a boxcar shaped trailer mounted on wheels with a hitch for connecting to a motor vehicle. The boxcar walls are hingedly connected to the floor and pivotally open, extending the boxcar platform. Preferred embodiments include truss systems mounted to the platform equipped with cylinder type braces or pulleys that facilitate manually or automatically opening and closing the boxcar walls.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not Applicable 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
       [0003]    Not Applicable 
       REFERENCE TO A SEQUENCE LISTING 
       [0004]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0005]    1. Field of the Invention 
         [0006]    This invention relates generally to expansible trailers adaptable to provide increased usable floor area, and relates more particularly to expansible trailers adaptable for use as a mobile gym. 
         [0007]    2. Description of Related Art 
         [0008]    Expandable trailers are not new. However, up to now, expandable trailers have been cumbersome to use, complicated to make, and expensive to build. A typical prior art example is disclosed in U.S. Pat. No. 4,135,755 to Steffens. In the Steffens patent the roof, walls, and floor of the structure are interconnected by a sophisticated arrangement of fastening elements, which are hydraulically or pneumatically controlled and operated. Design and assembly of the structure disclosed in the Steffens patent requires a fair amount of precision among interconnected parts. An error in arrangement of one element renders the entire structure inoperable. The precision design demands of the Steffens patent drives up manufacturing costs. Manufacture of the typical expansible trailer, in general, exceeds the purchase price of most motor vehicles (such as heavy duty pick up trucks) required to tow such trailers. An object of the present invention is to develop an expansible trailer, the manufacturing costs of which are in the range of the retail purchase price of a typical heavy duty conventional trailer. 
         [0009]    The mobile gym disclosed in U.S. Pat. No. 5,667,267 to Talucci appears simplistic. The Talucci patent discloses a trailer with expandable side panels which are lowered and raised by spring tensioning means, the construction and operation of which are very simple. However, the spring tensioning means themselves obstruct the usable area of the expanded floor. The Talucci patent is very simple to make and operate but does not disclose a simple means for maximizing the usable area of the expanded floor. An object of the present invention is to provide an expandable trailer that maximizes the usable area of the expanded floor, and whose operation is simple. Another object is to develop an expansible trailer whose walls are easily extended and retracted by a single person and in a substantially short time. An additional object of the present invention is to develop an expansible trailer, the manufacturing costs of which are in the range of the purchase price of a typical heavy duty conventional trailer. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    The present invention provides an expansible trailer with retractable walls, comprising a platform with a floor, an underside, and four peripheral edges. The trailer also comprises two sets of opposing walls. Each wall had an outside and inside surface and two sets of opposing peripheral edges. Each wall has a peripheral edge hingedly attached to a platform peripheral edge, forming a right angle between the wall inside surface and platform floor. Hinged in this fashion, the four walls and platform floor form a box with substantially square corners between the walls. Each wall is capable of swinging about its hinged edge to where the wall inside surface and the platform floor are coplanar. 
         [0011]    One set of opposing walls have hinged wall sections along the wall edges forming said corners. The hinged wall sections have inside and outside surfaces. The hinged wall sections partially overlap the other set of opposing walls when all the walls are upright at right angles with the platform floor, wherein the inside surface of each hinged wall section is coplanar with and faces the outside surface of one of the other opposing walls. In this orientation, the hinged wall sections are capable of being fastened to the outside surfaces of the other set of opposing walls, preventing the four walls from collapsing. Additionally, the hinged wall sections fill the gaps between the walls when the walls are coplanar with the platform floor, wherein the inside surfaces of the hinged wall sections are coplanar with the inside surfaces of the walls and the platform floor. 
         [0012]    The trailer also comprises a plurality of supports fixed to the outside surfaces of the hinged wall sections and fixed to the outside surfaces of all the walls proximal to each wall&#39;s free edge opposite the wall edge hinged to the platform floor. The supports have a load bearing capacity sized to support the weight of a wall or hinged wall section, and the weight of exercise equipment while being used by people when all walls are coplanar with the platform floor and the supports are wedged between the ground and the outside surfaces of the walls and hinged wall sections. 
         [0013]    Other objects and advantages of the present invention will be readily apparent upon a reading of the following brief descriptions of the drawing figures, detailed descriptions of preferred embodiments of the invention, the appended claims and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0014]    The above mentioned and other objects and features of this invention and the manner of attaining them will become apparent, and the invention itself will be best understood by reference to the appended drawings. In the course of the following detailed description, reference will be made to the appended drawings in which: 
           [0015]      FIG. 1 . An isometric of a preferred embodiment of the trailer with retractable walls in the upright position 
           [0016]      FIG. 2A . A side view of a preferred embodiment of the trailer with the walls in the upright position 
           [0017]      FIG. 2B . A side view of a preferred embodiment of the trailer with walls coplanar with the platform floor. 
           [0018]      FIG. 3 . An isometric of a preferred embodiment of the trailer illustrating the retractability of the hinged wall sections 
           [0019]      FIG. 4 . An isometric of a preferred embodiment of the trailer including railing 
           [0020]      FIG. 5 . An isometric of a preferred embodiment of the trailer including an arched truss wall retractable system 
           [0021]      FIG. 6A . A side view of a preferred embodiment of the trailer including an arched truss wall retractable system 
           [0022]      FIG. 6B . A side view of a preferred embodiment of the trailer including an arched truss wall retractable system with the walls coplanar with the platform floor 
           [0023]      FIG. 7 . An isometric of a preferred embodiment of the trailer with the walls coplanar with the platform floor including an arched truss wall retractable system 
           [0024]      FIG. 8 . A side view of a preferred embodiment of a hollow U section of the arched truss 
           [0025]      FIG. 9 . An isometric of a preferred embodiment of a dashpot 
           [0026]      FIG. 10 . A cut-away side view of a preferred embodiment of a hollow U section of the arched truss 
           [0027]      FIG. 11A . An isometric of a preferred embodiment of the trailer with a roof 
           [0028]      FIG. 11B . An isometric of a preferred embodiment with a roof illustrating the retractability of the hinged wall sections 
           [0029]      FIG. 12 . An isometric of a preferred embodiment with a roof, illustrating a wall retractable system using a truss, winches, pulleys, and cables 
           [0030]      FIG. 13 . An isometric of a preferred embodiment with a roof, illustrating a wall retractable system using a cylindrical column and beam truss system and a winch pulley system 
           [0031]      FIG. 14 . An isometric of a preferred embodiment, illustrating an attachable staircase 
           [0032]      FIG. 15 . An isometric of a preferred embodiment, illustrating an attachable wheel chair lift 
           [0033]      FIG. 16 . An isometric of a preferred embodiment illustrating a cylindrical column beam truss system 
           [0034]      FIG. 17 . An isometric of a preferred embodiment, illustrating the wall retractable system using a truss, cables, pulleys, and winches 
           [0035]      FIG. 18 . An isometric of a preferred embodiment illustrating the detachability of the cables 
       
    
    
     DESCRIPTION 
     Definitions 
       [0036]    Trailer. A Trailer is an un-powered vehicle having a substantially level, horizontal platform, pulled by a powered vehicle.
 
Dashpot. A dashpot is a mechanical device, a damper which resists motion via viscous friction. The resulting force is proportional to the velocity, but acts in the opposite direction, slowing the motion and absorbing energy. The dashpots referred to in this application are linear dashpots.
 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0037]    In the following description, like reference characters designate like or corresponding parts throughout the several views. Referring now to the drawings in detail, reference is made to  FIGS. 1 ,  2 A and B,  3 , and  4 . The present invention is an expansible trailer  20  (as in  FIG. 1 ) with retractable walls  21 ,  24 ,  26 ,  28 . The present invention comprises: a platform  59  with a floor  29 , an underside  54 , and four peripheral edges  28 ,  56 ,  57 , and  58 ; and two sets of opposing walls  21  and  26 , and  24  and  28 . Each wall  21 ,  24 ,  26 ,  28  has an outside and inside surface and two sets of opposing peripheral edges. Each wall  21 ,  24 ,  26 ,  28  has one of its peripheral edges hingedly attached to a separate platform peripheral edge  28 ,  56 ,  57 , and  58 . The walls  21 ,  24 ,  26 ,  28  are hinged such that they form an upright right angle between each wall  21 ,  24 ,  26 ,  28  inside surface and the platform floor  29 . In this orientation, the four walls  21 ,  24 ,  26 ,  28  and platform floor  29  form a box with substantially square corners  50 ,  51 ,  52 , and  53 , between the walls  21 ,  24 ,  26 ,  28 . Each wall is capable of swinging about its hinged edge to a position such that each wall&#39;s inside surface and the platform floor are coplanar (as in  FIG. 4 ). 
         [0038]    One set of opposing walls  21  and  26  have hinged sections  22 ,  23 ,  25 , and  27  along the wall edges forming said corners  50 ,  51 ,  52 , and  53 . The hinged wall sections  22 ,  23 ,  25 , and  27  have inside and outside surfaces. The hinged wall sections  22 ,  23 ,  25 , and  27  partially overlap the other set of opposing walls  24  and  28  when all the walls  21 ,  24 ,  26 ,  28  are upright, at right angles with the platform floor  29 . The hinged wall sections  22 ,  23 ,  25 , and  27  are capable of being fastened to the other set of opposing walls  24  and  28 , preventing the four walls  21 ,  24 ,  26 ,  28  from collapsing. The hinged wall sections  22 ,  23 ,  25 , and  27  fill the gaps between the walls  21 ,  24 ,  26 ,  28  when the walls  21 ,  24 ,  26 ,  28  are coplanar with the platform floor  29 ; the hinged wall sections  22 ,  23 ,  25 , and  27  also being coplanar with the platform floor  29  (as in  FIG. 4 ). 
         [0039]    The trailer  20  further comprises a plurality of supports  32  fixed to the outside surfaces of the hinged wall sections  22 ,  23 ,  25 , and  27  and all walls  21 ,  24 ,  26 ,  28  proximal to each wall&#39;s free edge opposite the wall edge hinged to the platform floor  29  (as in  FIG. 4 ). The supports  32  have a load bearing capacity sized to support the weight of a wall or hinged wall section, and the weight of exercise equipment while being used by people when all walls  21 ,  24 ,  26 ,  28  are coplanar with the platform floor  29  while the supports  32  are wedged between the ground and the outside surfaces of the walls  21 ,  24 ,  26 ,  28  and hinged wall sections  22 ,  23 ,  25 , and  27 . 
         [0040]    The trailer walls may be made out of any rigid material, preferably metal, capable of supporting the weight of typical exercise equipment while being used by people. The dimension of the walls and platform are not limited. The trailer platform may be the size of a typical light utility trailer, the size of a tractor trailer, or larger. The height of the walls may exceed the platform width. A preferable wall height would be approximately half the length of the platform, resulting in an expanded trailer floor area six times the floor area of the trailer in the retracted position. This advantage maximizes the usable floor area, as no prior art expandable trailer increases the usable floor as much. 
         [0041]    Now referring to  FIGS. 5 ,  6 A,  6 B,  7 ,  8 ,  9 , and  10 . Another preferred embodiment includes wall retractable means including an arched truss system  36  and dashpots  38  (as in  FIG. 5 ). The truss system  36  is mounted to the platform floor  29 . The truss system  36  comprises two hollow U sections  34  and  35  and a cylindrical beam section  33 . Each U section  34  and  35  has an inside and outside surface, two legs  44  spaced apart and connected by a curvilinear arch  43 , and tracks  37  extending from the foot  42  of each leg  44  to the arch  41 . The inside surface of the U sections  34  and  35  face each other. Each cylindrical beam  33  end is rigidly attached to the inside surface of a U section  34  and  35  at the middle of the arches  43 . All four legs  44  are securely fastened to the floor  29  near the corners  50 ,  51 ,  52 ,  53  between the walls  21 ,  24 ,  26 , and  28 . 
         [0042]    Each dashpot  38  has two ends  39  and  40 . One end  40  of each dashpot  38  is connected to the inside surface of a separate wall  21 ,  24 ,  26 ,  28  proximal to the wall free edge opposite the wall edge hinged to the platform floor  29  (as in  FIG. 7 ). The other end  39  of each dashpot  38  is slidably connected to a separate track  37 . Each dashpot  38  comprises a plurality of telescopically retractable cylinders  61 ,  62 , and  63  and a piston  60 . Each dashpot&#39;s cylinders  61 ,  62 , and  63  and piston  60  fully extend when the wall to which the dashpot  38  is attached is coplanar with the platform floor  29 . In this orientation, each dashpot end  39  connected to one of the tracks  37  slides to the foot  42  of the leg  44 . 
         [0043]    Now here is a description of how to use the preferred embodiment. When one of the walls  21 ,  24 ,  26 ,  28  is manually lifted to the upright position, the cylinders  61 ,  62 , and  63  and piston  60  fully and resistively retract forcing the dashpot end  39  connected to the track  37  to slide up the track  37 . When the walls  21 ,  24 ,  26 ,  28  are upright and the hinged wall sections  22 ,  23 ,  25 , and  27  are unfastened, the dashpots  38  provide resistance and retards each wall  21 ,  24 ,  26 , and  28  from pivoting about its hinged edge and falling according to the gravitational weight of the respective wall. In a another preferred embodiment, when the dashpots  38  are fully retracted, they lock and hold the walls  21 ,  24 ,  26 , and  28  in the upright positions. The advantages of these embodiments are profound, because a single person can expand and lower the walls easily and manually. Manufacturing costs are very low because parts can be massed produced and prefabricated. These preferred embodiments are sturdy and robust but do not require extreme precision to manufacture. These embodiment illustrate redundancies, wherein each wall is attached to two dashpots. If one breaks or malfunctions, one dashpot remains. The dashpots can be sized such that only one is necessary to provide the desired resistance. 
         [0044]    Still referring to  FIGS. 5 ,  6 A,  6 B,  7 ,  8 ,  9 , and  10 , another preferred embodiment comprises each dashpot  38  being connected to a winch  47  by a cable  45  and  49  (as in  FIG. 10 ) and operated by a remote control (not shown). Each winch  47  is fastened to the platform underside  54 . Each cable  45  and  49  is connected to a separate piston  60  (as in  FIG. 9 ) and extends through the cylinders  61 ,  62 , and  63 , through the dashpot end  39 , inside the track  37 , up through the arch  43 , down through the opposing leg  44 , through the floor  29  and to one of said winches  47 . 
         [0045]    Now here is a description of how to use the preferred embodiment. Operating the remote to reel in the cable attached to one of the winches  47 , in turn pulls the piston  60 , forcing one of the cylinders  61 ,  62 , and  63  to retract, and forcing the dashpot end  39  to slide up the track to the arch  41 , wherein the piston end  40  pulls one of the walls causing the wall to pivot about its free edge until the wall is in the upright position (as if  FIG. 5 ). Turning the winch  47  in reverse unwinds the cable  45  and  49 , wherein the weight of the wall pivots about its hinged edge until the wall is coplanar with the platform floor  29 , wherein cylinders  61 ,  62 , and  63  and piston fully extend, and the dashpot end  39  slides to the foot  42 . 
         [0046]    The material of the truss  36  should be metal, preferably steel. To reduce the overall weight on the platform  29 , the truss  36  may be made out of thermoplastic. The height of the truss  36  should be taller than the height of the walls  21 ,  24 ,  26 ,  28 . It is preferable to make the height of each truss leg  44  approximately six feet, so that people could walk under the truss arches  43 , making maximum use out of the extended floor area. The material of the cable should be metal, preferably steel. However, if the walls are lightweight, the cables may be fiberglass or rope. There are obvious advantages of using the truss  36 , dashpots  38 , cables  49 , and winches  48  to lower the walls. The truss  36  may be easily prefabricated and mass produced making manufacture cheap. Installing the truss  36 , dashpots  38 , cables  49 , and winches  48  is simple. More importantly, lowering and raising the walls is as simple as operating a remote control. Even without the cables  39 , winches  48 , and remote, lowering and raising the walls, using the truss  36  and dashpots  38  is easy, and can be operated by one person. A person can simply unfasten both of the hinged wall sections  22 ,  23 ,  25 , and  27  attached to a single opposing wall  24  or  28 , and the person will be able to lower the wall  24  or  28  manually, without having the wall  24  or  28  collapse too quickly because the dashpots  38  will arrest some of the weight of the wall as stated above. Then a person could unfasten the hinged wall sections  22 ,  23 ,  25 , and  27  attached to the other opposing wall  28  or  24 , allowing each opposing wall  21  and  26  to collapse under the resistance of the dashpots  38 , and then the person could lower the remaining opposing wall  28  or  24 . 
         [0047]    Now referring to  FIGS. 11A  and B,  12 ,  13 ,  14 ,  15 ,  16 ,  17 , and  18 , another preferred embodiment includes wall retractable means comprising a cylindrical column and beam truss system connected by cables and pulleys to remotely controlled winches. The truss system comprises four columns  66 ,  71 ,  72 , and  73  and four beams  88 ,  89 ,  90 , and  91 . One end of each column  66 ,  71 ,  72 , and  73  is rigidly fastened to the platform floor  29  near one of the corners  50 ,  51 ,  52 , and  53  (as in  FIG. 16 ). The beams  88 ,  89 ,  90 , and  91  are rigidly fastened between the columns  66 ,  71 ,  72 , and  73  at the other end of each column  66 ,  71 ,  72 , and  73  (as in  FIG. 16 ). Each pulley  75 ,  80 ,  92 ,  93  is anchored to a separate beam  88 ,  89 ,  90 , and  91 . All four winches  81 ,  82 ,  83 , and  84  are mounted to the platform underside  54  at the center of the platform  29 . The winch cables  74 ,  77 ,  78 , and  79  extend through apertures in the center of the platform floor  29  (as in  FIG. 17 ). Each cable  74 ,  77 ,  78 , and  79  is attached to a separate pulley  75 ,  80 ,  92 ,  93 , and fastened to the inside surface of a separate wall  21 ,  24 ,  26 ,  28  near the free wall edge opposite the wall edge hinged to the platform floor  29  (as in  FIGS. 17 and 18 ). 
         [0048]    Now here is a description of how to use the preferred embodiment. Operating one of the remote controls to reel in one of said cables pulls the wall to which the cable is attached, causing the wall to pivot about the wall edge hinged to the platform floor, lifting the wall to its upright position (as in  FIGS. 11A  and B, and  12 ). Operating one of the winches in reverse, to unwind one of the cables, has the opposite effect, wherein the weight of the wall against the tension in the unwinding cable causes the wall to collapse, pivoting about its edge hinged to the platform floor, until the respective wall is coplanar with the platform floor  29 , the falling rate of the wall being controlled by the remote. This embodiment provides the best means for lowering and raising the walls, because the dashpots  38  are unnecessary, reducing manufacturing costs. And it is very expedient to install the pulleys  75 ,  80 ,  92 ,  93  and winches  81 ,  82 ,  83 , and  84 . Also, a truss made out of cylindrical beams and columns is cheaper to manufacture than the arched truss  36 , because the cylindrical beams and columns are readily available. 
         [0049]    In another preferred embodiment, a roof  65  is mounted on top of the beams  88 ,  89 ,  90 , and  91 , providing shading from the sun (as in  FIG. 13 ). In another preferred embodiment, railing  85  is mountable along the inside surfaces of all the walls  21 ,  24 ,  26 , and  28  and hinged wall sections  22 ,  23 ,  25 , and  27  when the hinged wall sections are coplanar with the platform floor  29  (as in  FIG. 14 ). In another preferred embodiment a modular staircase  86  is mountable to the hinged wall sections&#39; free edges when the hinged wall sections  22 ,  23 ,  25 , and  27  are coplanar with the platform floor  29  (as in  FIG. 14 ). In another embodiment, a wheelchair lift  87  is mountable to at least one of the hinged wall sections&#39; edges when coplanar with the platform floor (as in  FIG. 15 ). In another embodiment, each cable  74 ,  77 ,  78 , and  79  is detachably fastened to each wall,  24 ,  26 , and  28 , wherein when a wall is coplanar with the platform floor, the cable may be detached, and reeled into one of the winches, whereby the cable does not obstruct the path of a person using the exercise equipment (not shown) mounted on the inside surfaces of the walls and hinged wall sections when coplanar with the platform floor (as in  FIG. 18 ). 
         [0050]    Referring again to  FIGS. 1 ,  2 A and B,  3 , and  4 , another embodiment comprises a substantially horizontal rectangular platform  59  comprising a floor  29 , an underside  54 , two longitudinal edges  55  and  57 , and two transverse edges  56  and  58 . The preferred embodiment further comprises opposing sidewalls  24  and  28 , each sidewall  24  and  28  having an inside surface and outside surface, a hinged edge  55  and  57  and an opposing free edge; each sidewall  24  and  28  being hingedly connected to one of the platform longitudinal edges  55  and  57 , wherein each sidewall  24  and  28  is capable of swinging about its hinged edge  55  and  57  between an upright position, relative to the platform floor  29 , and a horizontal position, substantially coplanar with the platform floor  29 . 
         [0051]    The preferred embodiment further comprises a front wall  21  comprising an inside surface and an outside surface, two panels  22  and  23  with inside and outside surfaces, a free edge and an opposing edge  58  hinged to a platform transverse edge  58 , and two opposing side edges  50  and  53  hinged to separate one of said panels  22  and  23 , wherein each panel  22  and  23  is capable of swinging about the respective panel&#39;s hinged edge  50  and  53  to a coplanar position relative to the front wall  21  and perpendicular to the front wall  21  when the front wall  21  is in an upright position relative to the platform floor  29 . The embodiment further comprises a rear wall  26  comprising, an inside surface and an outside surface, two panels  25  and  27  with inside and outside surfaces, a free edge and an opposing edge  56  hinged to the other platform transverse edge  56 , and two opposing side edges  51  and  52 , each respective rear wall side edge  51  and  52  hinged to one of said rear wall panels  25  and  27 , wherein each rear wall panel  25  and  27  is capable of swinging to a coplanar position relative to the rear wall  26  and a position perpendicular to the rear wall  26  when the rear wall  26  is in an upright position relative to the platform floor  29 . 
         [0052]    The preferred embodiment further comprises a plurality of sturdy angle braces  32  fixed to the outside surfaces of all walls  21 ,  24 ,  26 , and  28  and panels  22 ,  23 ,  25 , and  27 . The angle braces  32  attached to the panels  22 ,  23 ,  25 , and  27  are attached near the panel free edge opposite the respective panel hinged edge  50 ,  51 ,  52 , and  53 . The angle braces  32  attached to the front, rear and side walls  21 ,  24 ,  26 , and  28  are attached near the wall free edge opposite the wall edge  55 ,  56 ,  57 , and  58  hinged to the platform  29 . The angle braces  32  have a load bearing capacity sized to support the weight of a wall  21 ,  24 ,  26 , and  28  or panel  22 ,  23 ,  25 , and  27 , and the weight of exercise equipment while being used by people when all walls  21 ,  24 ,  26 , and  28  and panels  22 ,  23 ,  25 , and  27  are coplanar with the platform floor  29  and the angle braces  32  are wedged between the ground and the exterior surfaces of the walls  21 ,  24 ,  26 , and  28  and panels  22 ,  23 ,  25 , and  27 .