Abstract:
An expanding trailer has two nesting expandable modules. By using hinged arms operating from a central rotating axis, the two modules are extended simultaneously. Previously a problem was that the modules on either side extend unevenly which causes balance problems. This design permits two opposed modules to extend evenly and simultaneously. Also a mechanism is provided to level the floor of the extended modules with the central floor once extended.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority from United States provisional application no. 60/619,929 filed Oct. 20, 2004, which is pending. 
     
    
     TECHNICAL FIELD  
       [0002]     The invention relates to the field of expandible trailers and more particularly expandible trailers having sections which extend from and retract into the trailer body.  
       BACKGROUND  
       [0003]     Expandible trailers in which modules extend from the trailer to expand the interior space when stationary and are retracted into the trailer body for travel are known. U.S. Pat. No. 5,291,701 Delacollette discloses a semitrailer in which the central box is fixed on the trailer chassis and two sliding boxes surround the fixed box and can be extended to form an expanded interior space and retracted for transport. U.S. Pat. No. 5,170,901 Bersani discloses an expandible container in which the sides are hinged to permit structures to be extended to expand the interior space. A difficulty with such prior structures is that the modules on either side may extend at different rates which causes imbalance in the trailer and possible upsetting of the trailer. Also in some designs the level of the floor is uneven as between the central and extended sections.  
       SUMMARY OF INVENTION  
       [0004]     The present invention provides an expanding trailer which has two nesting expandable modules. In particular the invention provides an expandible trailer, reversibly expandible from a first retracted position to a second extended configuration, the trailer comprising: a) a trailer body mounted on a trailer frame and having a floor and openings on opposed sides receive expansion modules; b) first and second nesting expansion modules couplably and simultaneously movable in opposed directions between a first retracted position wherein the first and second nesting modules are nested within the trailer body above the floor with the second module nested within the first module, to a second extended position, and wherein each module has a floor; c) means for supporting the modules in the extended configuration on the trailer frame; d) power means for selectively moving the modules between the retracted and extended positions; and e) means for lowering and raising the first and second modules to and from a position where the floors of the modules are level with the trailer body floor. The invention further provides a method of expanding a trailer.  
         [0005]     By using hinged arms operating from a central rotating axis, supports on both ends of the two modules are extended simultaneously. This design permits two opposed modules to extend evenly and simultaneously while leveling the floor sections in the extended modules with the level of the floor in the central section.  
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0006]     In drawings which illustrate a preferred embodiment of the invention:  
         [0007]      FIG. 1  is an elevation view of the trailer of the invention in expanded state;  
         [0008]      FIG. 2  is a cross-sectional view taken along lines  2 - 2  of  FIG. 5 , with the retracted configuration in dotted outline;  
         [0009]      FIG. 3  is a is a cross-sectional view taken along lines  3 - 3  of  FIG. 1  while expanding;  
         [0010]      FIG. 4  is an end view of the invention in collapsed state for transport;  
         [0011]      FIG. 5  is an end view of the invention in expanded state;  
         [0012]      FIG. 6  is a cross-sectional view of a second embodiment of the invention taken along lines  2 - 2  of  FIG. 5  with the retracted configuration in dotted outline;  
         [0013]      FIG. 7  is a cross-sectional view of an embodiment of the invention taken along lines  3 - 3  of  FIG. 1  in extended configuration showing a first embodiment of the floor-leveling mechanism prior to leveling of the floors;  
         [0014]      FIG. 8  is a cross-sectional view of the embodiment shown in  FIG. 7  after leveling of the floors;  
         [0015]      FIG. 9  is a cross-sectional view of an embodiment of the invention taken along lines  3 - 3  of  FIG. 1  in extended configuration showing a second embodiment of the floor-leveling mechanism prior to leveling of the floors;  
         [0016]      FIG. 10  is a cross-sectional view of the embodiment shown in  FIG. 9  after leveling of the floors;  
         [0017]      FIG. 11  is a detail end view of the lifting cross shaft used in the embodiment of the leveling mechanism shown in  FIG. 7 ;  
         [0018]      FIG. 12  is a detail end view showing the linking of three of the lifting cross shafts and used in the embodiment of the leveling mechanism shown in  FIG. 7 ;  
         [0019]      FIG. 13  is a detail end view of the lifting cross shaft used in the embodiment of the leveling mechanism shown in  FIG. 7 ;  
         [0020]      FIG. 14  is a detail elevation view of the rollers used in the invention; and  
         [0021]      FIG. 15  is a side view of the rollers in the embodiment of the leveling mechanism shown in  FIG. 9 . 
     
    
     DESCRIPTION  
       [0022]     Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.  
         [0023]     With reference to  FIGS. 1-5 , a semi-trailer truck  10  has a truck tractor  12  connected to trailer  14 . Trailer  14  has a chassis  15  to which wheels  16 , axle  18  and cargo box  20  are fixed to the chassis. Vertical sides  22  of cargo box  20  have cut-out openings  24 ,  26  to receive expandible modules  30 ,  32 . Modules  30 ,  32  have top panels  34 ,  36 , bottom panels  38 ,  40 , side panels  42 ,  44  and ends  46 ,  48 ,  50 ,  52 , and are open to the interior of cargo box  20 . Side panels  42 ,  44  have flanges  41 ,  43 ,  45 ,  47  which seal the openings  24 ,  26  when the modules are retracted. Module  32  is smaller than module  30  so that it fits within module  30  when retracted ( FIG. 4 ).  
         [0024]     End  52  of cargo box  20  has door  54  and removable steps  56 , flood lights  58  and stair lights  60 . Windows  62 , door  64  and removable steps  66  are provided on module  30 . Electrical box  68  with hinged access panel  70  is provided for electrical, telephone and computer connections. An air conditioning unit is provided at  72 .  
         [0025]     A first embodiment of the mechanism for extending and retracting modules  30 ,  32  is shown in  FIG. 2 . Hydraulic cylinders  74 ,  76  are connected to pivoting element  78  in the extended position. Reference numeral  80  shows pivoting element  78  in the retracted position. Element  78  is connected to hinged support arms  82 ,  84 ,  86 ,  88  by rods  81 ,  85 ,  91  and  93 . In the retracted position, wherein hinged support arms  82 ,  84 ,  86 ,  88  are shown in dotted outline, the connecting rods are in the positions designated as rods  83 ,  87  and  89 ,  95 . The ends of hinged support arms  82 ,  84 ,  86 ,  88  are pivotally secured to sides  42 ,  44  of modules  30 ,  32  at  90 ,  92 ,  94 ,  96 . Retracting cylinders  74 ,  76  causes hinged support arms  82 ,  84 ,  86 ,  88  to fold and retract modules  30 ,  32  into cargo box  20  while extending cylinders  74 ,  76  causes hinged support arms  82 ,  84 ,  86 ,  88  to unfold and extend modules  30 ,  32  from cargo box  20 . Once modules  30 ,  32  are extended, the floors are leveled as described below and support legs  98 ,  100  are lowered into contact with the ground  102 .  
         [0026]     In operation the modules  30 ,  32  are extended from the position shown in  FIG. 4  when the trailer is stationary by activating hydraulic cylinders  74 ,  76  which unfold support arms  82 ,  84 ,  86 ,  88  and causes modules  30 ,  32  to extend to the position shown in  FIG. 5 . The floors are then leveled and support legs lowered. The process is reversed to retract the modules which are locked in the retracted position for transport.  
         [0027]      FIG. 6  illustrates an embodiment having three pairs of hinged support arms  102 ,  104 ,  106 ,  108 ,  110 ,  112  in the extended position, with arms  104 ,  106 ,  112  shown in dotted outline in the retracted position. Hinged support arms  102 ,  104 ,  106 ,  108 ,  110 ,  112  are pivotally connected to the sides  42 ,  44  of modules  30 ,  32  at  114 ,  116 ,  118 ,  120 ,  122 ,  124 . This embodiment may also use linkages  103 ,  105  to ensure that the arms deploy in unison to keep the modules square.  
         [0028]     A first embodiment of the mechanism for leveling the floor of the extended trailer is shown in  FIGS. 7 and 8 . Cargo box  20  has floor  130 . Larger module  30  has floor  132  which extends on rollers  134 , mounted on the lower surface of floor  132 , and roller  136  mounted on arm  106 . Rollers  134  roll on floor  130  as module  30  extends and so are above floor  130  as it extends. Smaller module  32  has floor  138  which extends on rollers  140 , mounted on the lower surface of floor  138 , and rollers  142  mounted on arm  112 . As module  32  is nested inside module  30 , rollers  142  are located above rollers  136  and rollers  140  roll on floor  132  when module  32  is nested inside module  30 . Rollers  134  and  140  are preferably a series of nylon rollers mounted on the lower inboard edges of modules  30 ,  32 . Rollers  136 ,  142  are each formed as a series of rollers  136  and are mounted on a support bar  180  which runs the length of the box ( FIG. 14 ). Support bar  180  is mounted on box structures  137 ,  143  which are secured to arms  106 ,  112 , are raised and lowered with arms  106 ,  112  as described below and are open to allow pivoting of the arms. Corresponding roller structures are associated with each pair of support arms. The longitudinal support bar  180  carries the inboard weight of the modules  30 ,  32  while arms  106 ,  112  carry the outboard weight. As the modules  30 ,  32  contract, the support arms  106 ,  112  close in on the rollers  136 ,  142  and the modules tip up slightly onto the rollers  134 ,  140  to avoid scraping the floors on the last part of the travel of the modules as the center of gravity shifts.  
         [0029]     Parallelogram linkages  144 ,  148  are pivotally connected at their inner ends to the trailer chassis  15  and at their outer ends to support arms  106 ,  112  and box structures  137 ,  143 . In the retracted transport configuration the linkages  144 ,  148  are parallel to the ground  102  for increased ground clearance as shown in  FIG. 7 . After the modules have been extended, the linkages  144 ,  148  are pivoted by hydraulic cylinder  170  attached to frame  15  or electric power to lower arms  106  and  112  so that floors  132 ,  130  and  138  are level as shown in  FIG. 8 . Arms  102 ,  104 ,  106  are lowered a lesser amount than arms  108 ,  110 ,  112  by using cross shafts  151  as shown in  FIGS. 11-13  having welded thereto a drive lever  150  driven by hydraulic cylinder  170  through link bar  172  and raining levers  152 ,  154  connected to linkages  144 ,  148 . One cross shaft  151  is used per left and right pair of support arms i.e. one for arms  106  and  112 , a second for  104 ,  110  and a third for  102 ,  108 . The cross-shaft is rotated about 90 degrees, driven by the hydraulic cylinder  170  or electric actuator, with the three cross-shafts  151  tied together by a lever and link bar  172  so that they operate in unison. As shown in  FIGS. 12, 13 , this arrangement provides for a differential in height increase C between the position A in  FIG. 12  and position B in  FIG. 13 . In the preferred embodiment the vertical lift is about 3.5 inches for arm  106  and 7 inches for arm  112 .  
         [0030]     A second embodiment of the mechanism for leveling the floor of the extended trailer is shown in  FIGS. 9 and 10 . In this embodiment the support arms  106 ,  112  slide up and down on king posts  160 ,  162 . Each pair of support arms has a pair of king posts. The raising and lowering of the arms is carried out by hydraulic or electric actuators which are configured to provide the appropriate amount of vertical travel for each support arm to achieve a level surface across the three floors  132 ,  130 ,  138  as shown in  FIG. 10 .  
         [0031]     As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof.