Patent Publication Number: US-2022234512-A1

Title: Assemblies for supporting a load relative to a roof of a vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation-In-Part of U.S. patent application Ser. No. 16/738,144, filed on 9 Jan. 2020, which claims priority to Australian Provisional Patent Application Nos. 2019900072 and 2019901954, filed on 10 Jan. 2019 and 6 Jun. 2019, respectively. The content of these applications is incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to assemblies for supporting a load relative to a vehicle, such as above the roof, or above the tub or bed of a utility vehicle/truck. 
     BACKGROUND 
     To increase cargo earning capacity of a vehicle it is common to secure roof racks/bars to a roof of a vehicle. Such racks allow a load to be supported above the roof. To further enhance this arrangement, a roof tray may also be secured to the roof (or the roof racks). Roof trays provide a platform on which the load is supported and often include a guard rail extending around the platform to assist retaining the load on the platform. 
     The platform of a roof tray usually comprises a plurality of joined slats or bars to which objects, such as cargo or roof tray accessories, are removably secured. The objects are typically secured to the platform by various brackets and/or clamps, which may be configured to secure specific cargo to the roof tray, such as a bespoke shovel bracket or jack mount. 
     Additionally or alternatively, a tub or bed rack may be affixed across a tub/bed of a utility vehicle (also referred to as a pickup truck, or truck). Such racks typically comprise support bars arranged along or between opposed sides of the tub, and cross-bars secured between the side bars to form a rigid frame. The cross-bars and/or support bars can provide a platform on which to support cargo. 
     Providing a robust connection between the objects and a roof tray or tub rack can prove important as failure of this connection can result in the objects being lost during transit. This issue can be exacerbated if the vehicle is driven across uneven surfaces, such as when driving the vehicle ‘off-road’, as travelling across such surfaces typically transfers substantial vibrations/shocks to the roof tray and/or tub rack which increase the likelihood of the connection failing. 
     Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims. 
     SUMMARY 
     According to some disclosed embodiments, there is provided an assembly for supporting a load relative to a vehicle, the assembly comprising: an elongate bar configured for fixing to the vehicle, the elongate bar having a sidewall and at least one support structure, the at least one support structure defining a pair of opposed, diverging retention surfaces, each retention surface extending away from the sidewall; and at least one engaging mechanism configured to be secured to the load, the at least one engaging mechanism defining a pair of opposed abutment surfaces shaped to be complementary to the retention surfaces, the abutment surfaces configured so that, in use, each abutment surface abuts and lies against one of the retention surfaces, the at least one engaging mechanism operable to urge the abutment surfaces against the retention surfaces to engage the elongate bar. 
     The elongate bar may include a pair of the support structures, where a first support structure extends from the sidewall in a first direction, and a second support structure extends from the sidewall in a second direction arranged transverse to the first direction. 
     The elongate bar may be shaped such that the second direction is arranged at an angle equal to, or greater than. 90 degrees to the first direction. 
     The elongate bar may be shaped such that, in use, the first direction is horizontal, and the second direction is generally downwards. 
     The at least one support structure may be at least partially surrounded by a recess defined by the sidewall. 
     The retention surfaces may be defined by at least one flange extending from the sidewall. The retention surfaces may be defined on opposed sides of a flared flange. 
     The elongate bar may be formed from an extrusion, and the support structure is an integrally formed portion of the extrusion. 
     The engaging mechanism may comprise two portions, each portion defining one of the abutment surfaces, and wherein at least one of the portions is movable relative to the other portion, so that, in use, the abutment surfaces urge against the retention surfaces. 
     The engaging mechanism may include an actuator operable to move at least one of the portions relative to each other. The actuator may be arranged to exert a linear force transversely to the retention surfaces. 
     Each retention surface may be planar, and the actuator be arranged to exert a linear force parallel to the plane of one of the retention surfaces. 
     The elongate bar may define opposed ends and form an arch between the ends, and the elongate bar be configured to have each end fixed to a tub of a vehicle to arrange the arch along a side, or between opposed sides, of the tub. The arch of the elongate bar may comprise a straight mid-section interposed between a pair of end portions. Each end portion may define a curved portion such that, in use, the mid-section is arranged to be elevated from the tub of the vehicle. 
     The elongate bar may be configured as part of a frame configured for securing across a tub or a utility vehicle. In such embodiments the bar may be formed from sheet metal and joined to other elongate members to form the frame, such as by welding and/or with fasteners. 
     According to other disclosed embodiments, there is provided a vehicle tub rack assembly including: a pair of elongate bars configured for fixing to a tub of a vehicle to be spaced apart, each elongate bar having a sidewall and at least one support structure, the at least one support structure defining a pair of opposed, diverging retention surfaces, each retention surface extending away from the sidewall; and at least one engaging mechanism defining a pair of opposed abutment surfaces shaped to be complementary to the retention surfaces, the abutment surfaces configured so that, in use, each abutment surface abuts and lies against one of the retention surfaces, the at least one engaging mechanism operable to urge the abutment surfaces against the retention surfaces to engage one of the elongate bars. 
     The pair of elongate bars may be configured such that, in use, the at least one support structure of one of the elongate bars is arranged to extend towards the at least one support structure of the other elongate bar. 
     The tub rack assembly may include at least one cross-bar and an associated pair of the engaging mechanisms, each of the engaging mechanisms secured to the cross-bar and arranged to, in use, engage both of the elongate bars to arrange the cross-bar between the elongate bars. 
     Each of the elongate bars may define a support surface at an operatively top of the bar, and the at least one cross-bar comprise a slat defining opposed ends, and wherein each of the engaging mechanisms associated with the cross-bar are secured to one of the ends of the slat to allow, in use, arranging the slat to be flush with, or operatively below, the support surface. 
     According to other disclosed embodiments, there is provided a vehicle tub rack assembly including: a frame configured for fixing across a tub of a utility vehicle, the frame comprising a plurality of elongate members, and wherein at least one of the elongate members has a side and at least one support structure, the at least one support structure defining a pair of opposed, diverging retention surfaces, each retention surface extending away from the side; and at least one engaging mechanism defining a pair of opposed abutment surfaces shaped to be complementary to the retention surfaces, the abutment surfaces configured so that, in use, each abutment surface abuts and lies against one of the retention surfaces, the at least one engaging mechanism operable to urge the abutment surfaces against the retention surfaces to engage one of the elongate bars. 
     Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. 
     It will be appreciated embodiments may comprise steps, features and/or integers disclosed herein or indicated in the specification of this application individually or collectively, and any and all combinations of two or more of said steps or features. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Embodiments will now be described by way of example only with reference to the accompany drawings in which: 
         FIG. 1  is a perspective view of a vehicle roof tray assembly configured as a platform; 
         FIGS. 2 to 4  are perspective, side and end views, respectively, of a slat which forms part of the platform shown in  FIG. 1 ; 
         FIGS. 5 to 7  are perspective, top and end views, respectively, of an alternative configuration of the slat shown in  FIGS. 2 to 4 ; 
         FIGS. 8 to 10  are perspective, top and end views, respectively, of an alternative slat which forms part of the platform shown in  FIG. 1 ; 
         FIG. 11  is a perspective view of an alternative configuration of the assembly shown in  FIG. 1  including a guard rail arranged along one side of the platform; 
         FIGS. 12 to 14  are perspective, exploded and cross-section views, respectively, of a mechanism for securing the guard rail to a slat of the assembly; 
         FIGS. 15 and 16  are perspective and exploded views, respectively, of an alternative mechanism for securing the guard rail to the slat; 
         FIGS. 17 and 18  are perspective views of alternative configurations of the assembly shown in  FIG. 1  including a guard rail arranged along three sides of the platform ( FIG. 17 ), and in a continuous loop around a periphery of the platform ( FIG. 18 ); 
         FIGS. 19 and 20  are perspective and cross-section views, respectively, of a mechanism for releasably connecting to one of the slats; 
         FIGS. 21 and 22  are perspective and cross-section views, respectively, of an alternative mechanism for releasably connecting to one of the slats; 
         FIGS. 23 and 24  are perspective views of alternative configurations of a further alternative mechanism for releasably connecting to one of the slats; 
         FIG. 25  is a perspective view of an alternative embodiment of a vehicle roof tray assembly configured as a platform; 
         FIG. 26  is a perspective view of a slat which forms part of the platform shown in  FIG. 25 ; 
         FIGS. 27 and 28  are perspective and end views, respectively, of an alternative slat which forms part of the platform shown in  FIG. 25   
         FIG. 29  is a perspective view of an assembly for supporting a load relative to a vehicle, the assembly configured as a tub rack to be affixed to the tub of the vehicle; 
         FIG. 30  is an environmental view showing the assembly of  FIG. 29  secured to the tub of a vehicle and carrying the platform shown in  FIG. 25 ; 
         FIG. 31  is a side cross-section view, and  FIG. 32  is an end cross-section view, respectively, of the assembly shown in  FIG. 29 ; 
         FIG. 33  is a detailed end cross-section view of the assembly shown in  FIG. 29  to which the platform shown in  FIG. 25  is mounted; 
         FIG. 34  is another detailed end cross-section view of the assembly shown in  FIG. 29 ; and 
         FIG. 35  is a perspective cross-section view of a component of the assembly shown in  FIG. 29 , being a side bar. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the drawings, reference numeral  10  generally designates a vehicle roof tray assembly  10  for supporting a load (not illustrated) relative to a roof of a vehicle (not illustrated). The assembly  10  includes a plurality of elongate members, in the form of slats  12 , connected together to form a platform  14  ( FIG. 1 ), and an engaging mechanism  16  ( FIG. 11 ). Each slat  12  defines a support surface  18  for supporting the load, and each slat  12  has a pair of opposed, diverging retention surfaces  20  extending outwardly from the support surface  18 . The engaging mechanism  16  is configured so that; in use, the engaging mechanism  16  abuts the retention surfaces  20  of one of the slats  12  to engage the slat  12 . 
       FIG. 1  shows the vehicle roof tray assembly  10 . The roof tray  10  comprises cross-slats  22 ,  23  which are joined to side-slats  24  to form the platform  14 . The platform  14  is configured to be affixed to a roof of a vehicle (not illustrated), or to roof racks/roof bars (not illustrated) which are secured to the vehicle, to support the load relative to the roof. The platform  14  is typically secured to the roof of the vehicle by a bracket (not illustrated) which is configured to conform and be fitted to a roof profile of one or more specific vehicle models. 
     The platform  14  is formed by a linear array of first cross-slats  22  and a pair of second cross-slats  23 , arranged at opposed sides of the array, being joined to a pair of opposed side-slats  24 . A corner assembly  26  is secured at each corner of the platform  14 . The corner assembly  26  includes a pair of housings (not illustrated) which are arranged on opposed sides of the platform  14  and joined to each other, typically by a plurality of fasteners (not illustrated). 
     As shown in  FIG. 10 , each side-slat  24  defines a sloped junction surface  28  extending from one side of the support surface  18  diagonally towards the other side of the support surface  18 . As shown in  FIGS. 2 and 3 , each end of each first cross-slat  22  is obliquely shaped to abut the junction surface  28 . As shown in  FIG. 5 , each end of the second cross-slat  23  is also obliquely shaped to abut the junction surface  28 . To assemble the platform  14 , the cross-slats  22 ,  23  are arranged to abut the junction surfaces  28  of the side-slats  24  and welded to permanently affix the slats  22 ,  23 ,  24  together. It will be appreciated that other joining techniques may be employed, such as bonding with adhesive(s) and/or connecting with mechanical fasteners. 
       FIGS. 2 to 7  show the first and second cross-slats  22 ,  23 . The second cross-slat  23  is an alternative configuration of the first cross-slat  22 , where the ends of the second cross-slat  23  are shaped differently to the ends of the first cross-slat  22 . The alternative configuration of the ends of the second cross-slat  23  enhances fitting within the corner assembly  26 . 
     Each cross-slat  22 ,  23  defines the support surface  18 , in the embodiment shown, being a substantially planar top surface  18  defining three ridges  19  to enhance friction between the support surface  18  and the supported load. Viewed in cross-section ( FIGS. 4, 7 ), the support surface  18  extends in a direction A-A. A pair of retention surfaces  20  are arranged extending outwardly from each side of the support surface  18  to diverge relative to the direction A-A. It will be appreciated that the retention surfaces  20  may be alternatively arranged to extend away from the support surface  18 , for example, to extend perpendicularly away from the support surface  18  (not illustrated). 
     Each cross-slat  22 ,  23  defines a base surface  38  either side of a base channel  39 . The channel  39  is configured to receive a bracket (not illustrated) or fastener (not illustrated) to secure the slat  22 ,  23  to the vehicle (or a roof rack). The arrangement of the channel  39  in combination with the oblique shaped ends of the slats  22 ,  23  mean that the bracket/fastener can be arranged at any position along the slat  22 ,  23 , including at or close to the end of the slat  22 ,  23 , thereby optimising a range of positions available for fastening to suit a range of roof geometries defined by various models of vehicles. 
     In the illustrated embodiment, the cross-slat  22 ,  23  includes a side-wall  30  extending at each side of the support surface  18  and substantially perpendicular to the support surface  18 . It will however be appreciated that the side-wall  30  may be alternatively configured to extend otherwise transverse to the support surface  18 , for example, to define an oblique side-wall (not illustrated). 
     A flared flange  32  extends from at least one of the side-walls  30 , in the embodiment shown, extending from each side-wall  30 . The flange  32  defines the retention surfaces  20  on opposed sides, the retention surfaces  20  being configured as substantially planar surfaces arranged at an angle to the direction A-A, and includes an end face  34  joining a free end of each retention surface  20 . A junction section  36  spaces the retention surfaces  20  from the side-wall  30 . The flange  32  defines a free end, at the end wall  34 , which is spaced operative below the plane of the support surface  18 . This positions the entirety of the flange  32  at a level below the level of the support surface  18 . It will however be appreciated that the flange  32  may be alternatively arranged, for example, to extend directly from the support surface  18  (not illustrated). 
     It will be appreciated that the cross-slats  22 ,  23  may be alternatively configured so that the retention surfaces  20  are arranged in an alternative position relative to each other and/or the support surface  18 . For example, each cross-slat  22 ,  23  may have one of the retention surfaces  20  arranged immediately adjacent the support surface  18  to form an angled lip (not illustrated) running along an edge of the support surface  20 . In this embodiment, the other retention surface  20  may be arranged immediately adjacent a base surface  38  to form another lip running along an edge of the base surface  38 . Alternatively, or additionally, the retention surfaces  20  may not be joined by an end face  34  and, instead, define an at least partially open side of the cross-slat  22 ,  23 . Further alternatively, the retention surfaces  20  may be defined on a pair of spaced, separate flanges or fins (not illustrated) extending at an angle from one of the side-walls  30 . It will also be appreciated that the junction section  36  may be absent so that the retention surfaces  20  extend directly from the side-wall  30 . 
       FIGS. 8 to 10  show the side-slat  24 . The side-slat  24  shares features with the cross-slats  22 ,  23 , whereby common reference numerals indicate common features. 
     The side-slat  24  defines the support surface  18  and two ridges  19 . Viewed in cross-section ( FIG. 10 ), the support surface  18  extends in the direction B-B. A pair of retention surfaces  20  are arranged at one side of the support surface  18  to diverge away from the direction B-B. In the illustrated embodiment, the side-slat  24  includes a side-wall  30  extending at one side of the support surface  18  and the junction wall  28  extending from the other side of the support surface  18 . The flared flange  32  extends from the side-wall  30  to define the retention surfaces  20 , end face  34  and junction section  36 . 
     In the illustrated embodiments, each of the cross-slats  22 ,  23  and side-slat  24  are formed as extrusions to define a consistent cross-section along a longitudinal length so that the flange  34  runs along the length of each slat  22 ,  23 ,  24 . This means that when the slats  22 ,  23 ,  24  are connected together to form the platform  14 , some of the flanges  34  extend from a periphery of the platform  14  to form a substantially continuous rail around the platform  14 . This allows any of the engaging mechanisms  16  (discussed below) to be installed or removed at virtually any position around the periphery of the platform  14 . Similarly, any of the engaging mechanisms  16  may be secured to any position along a side of any of the cross-slats  22 ,  23 . 
     Each of the support surface  18  and the retention surfaces  20  are integrally formed surfaces of the extrusion. Configuring the slats  22 ,  23   24  as extrusions can prove cost-effective to manufacture as considerable lengths of each extrusion can be fabricated and then cut to a desired length and end profile. It will be appreciated that any of the slats  22 ,  23 ,  24  may be alternatively configured to comprise more than one part (not illustrated), including more than one extrusion, so that, for example, one part defining one or both retention surfaces  20  is joined to another part defining the support surface  18 . 
       FIG. 11  shows an alternative configuration of the roof tray assembly  10  having a guard rail assembly  40  secured to the platform  14 . The guard rail assembly  40  includes a plurality of engaging mechanisms  16  configured to releasably secure a guard rail  42  to the platform  14  and support the guard rail  42  relative to the support surface  18 . 
       FIGS. 12 to 16  show two configurations of the engaging mechanism  16 .  FIGS. 12 to 14  show the engaging mechanism  16  configured as a support bracket sub-assembly  44 .  FIGS. 15 and 16  show the engaging mechanism  16  configured as an end cap sub-assembly  46 . Whilst the sub-assemblies  44 ,  46  are shown secured to the flange  32  of the side-slat  24  it will be appreciated that the sub-assemblies  44 ,  46  are configured to be securable to the flange  32  of any of the cross-slats  22 ,  23 . 
     The support bracket sub-assembly  44  comprises a first portion, configured as a bracket  48 , and a second portion, configured as a cover  50 , which is movable relative to the bracket  48 . Each of the bracket  48  and the cover  50  define at least one abutment surface  52  arranged to, in use, abut against one of the retention surfaces  20 . In the illustrated embodiment, each abutment surface  52  is configured to be complementary to the retention surface  20 , being substantially planar and sloped at a complementary angle so that, in use, the abutment surface  52  lies against the retention surface  20 . 
     The cover  50  is secured to the bracket  48  by an actuator, configured as a bolt  54 , which is operable to cause at least one of the abutment surfaces  52  to move. Operating the bolt  54  draws the cover  50  towards the bracket  48 . The bolt  54  is arranged transverse to the plane of the support surface  18 , in the illustrated embodiment, being parallel to the angle of one of the retention surfaces  20 . Arranging the bolt  54  in this way means that when the bolt  54  is operated, this exerts a linear force along an axis of the bolt  54  which causes the abutment surface  52  of the cover  50  to move along the adjacent retention surface  20 . This action also at least partially urges the abutment surfaces  52  towards each other to clamp against the retention surfaces  20  to engage the sub-assembly  44  with the slat  24 . This action may also cause the cover  50  to clamp against the end wall  34  of the flange  32 . 
     The bracket  48  defines a free end  49  configured to join to the guard rail  42 , typically being welded in place. The bracket  48  is shaped to abut against at least one of the support surface  18  and the end face  34 . Shaping the bracket  48  in this way minimises movement of the bracket  48  relative to the slat  24  in the direction B-B, thereby assisting positioning the guard rail  42  relative to the support surface  20 . This arrangement is useful as this allows the guard rail  42 , joined to a plurality of brackets  48 , to be lowered on to the platform  14  and easily located on adjacent flanges  32 . The bracket  48  defines an aperture  56  and associated recess  58  which arranges the bolt  54  at the required angle, transverse to the direction B-B. In the illustrated embodiment, the bracket  49  is formed as an extrusion. 
     The cover  50  is shaped to at least partially cover the bracket  48  and define an opening  60 . The opening  60  defines a re-entrant portion  62 , defining an at least partially hooked shape, at one side, a side-wall  64  extending from the re-entrant portion  62 , and a sloped surface  66  extending from the side-wall  64  and arranged to at least partially slope away from the re-entrant portion  62 . The side-wall  64  is dimensioned to receive the free ends of the retention surfaces  20 , in the embodiment shown, by receiving the end face  34  of the flange  32 . The re-entrant portion  62  defines the abutment surface  52 . Configuring the opening  60  in this way means that the cover  50  wraps around only one side of the flange  32 , thereby allowing the cover  50  to be readily installed and removed from the bracket  48  from outside the periphery of the platform  14 , thereby securing the guard rail  42  to the platform  14 . 
     The cover  50  houses a threaded insert  63  arranged to receive and threadedly engage with the bolt  54 . It will however be appreciated that the bracket  48  and cover  50  may be alternatively configured so that the bracket  48  houses the insert  63  and the bolt  54  be operated from the cover-side, where the bolt  54  is inserted through the cover  50  to engage with the insert  63 . In the illustrated embodiment, the cover  50  is formed as an injection moulding or die-casting. 
     The end cap sub-assembly  46  comprises a first portion, configured as an inner bracket  64 , a second portion, configured as an outer bracket  66  and which is movable relative to the inner bracket  64 , and an alternative cover  68 . Each of the inner bracket  64  and the outer bracket  66  define at least one abutment surface  52  arranged to, in use, abut against one of the retention surfaces  20 . 
     The inner bracket  64  defines a wall  65  arranged to join to the guard rail  42 , typically being welded in place. The inner bracket  64  is shaped to receive a portion of the support surface  18 , side-wall  30 , junction section  36 , and one retention surface  20 . The inner bracket  64  has a tab  70  which defines an aperture for a bolt  72 . The arrangement of the tab  70  arranges the bolt  72  transverse to the direction B-B and generally parallel to one of the retention surfaces  20 . In the illustrated embodiment, the inner bracket  64  is formed from sheet metal. 
     The outer bracket  66  defines a re-entrant portion  74  at one side, defining an at least partially hooked shape, a side-wall  76  extending from the re-entrant portion  74 , a sloped surface  78  extending from the side-wall and arranged to at least partially slope away from the re-entrant portion  74 , and a tab  80  extending from the sloped surface  78  and defining an aperture for the bolt  72 . The side-wall  76  is dimensioned to receive the end face  34  of the flange  32 . The re-entrant portion  74  defines the abutment surface  52 . Operating the bolt  72  draws the abutment surface  52  of the re-entrant portion  74  along the adjacent retention surface  20  causing the outer bracket  66  and inner bracket  64  to clamp the flange  32 . In the illustrated embodiment, the outer bracket  66  is formed from sheet metal. 
     The cover  68  is shaped to cover the inner bracket  64  and the outer bracket  66 . The cover  68  defines a thread to allow a fastener  82  to secure the cover  68  to the inner bracket  62 . The cover defines an opening  69  at one end having a complementary shape to the flange  32 . The opening  69  allows the cover  68  to be slid over the flange  32  from one end of the slat  24 , or be resiliently deformed to snap-fit over the flange  32 , so that the cover  68  engages the flange  32 . In the illustrated embodiment, the cover  68  is formed as an injection moulding or die-casting. 
       FIGS. 17 and 18  show alternative configurations of the assembly  10  having different guard rail assembly  40  configurations.  FIG. 17  shows the guard rail assembly  40  configured so that the guard rail  42  extends around three sides of the platform  14  and is mounted to the platform by eight support bracket sub-assemblies  44  and two end cap sub assemblies  46 .  FIG. 18  shows the guard rail assembly configured so that the guard rail  42  extends around all four sides of the platform  14  and is secured to the platform  14  by ten support bracket sub-assemblies  44 . 
       FIGS. 19 to 24  show three alternative configurations of the engaging mechanism  16  configured as various tie-down assemblies, each configured to enable a user to secure a strap, rope, cable, or the like, to the platform  14  to allow the user to tie the load to the platform  14 .  FIGS. 19 and 20  show the engaging mechanism  16  configured as a quick release tie-down sub-assembly  86 .  FIGS. 21 and 22  show the engaging mechanism  16  configured as a strap tie-down sub-assembly  88 .  FIGS. 23 and 24  show the engaging mechanism  16  configured as variations of a heavy duty tie-down sub-assembly  90 ,  92 ,  94 . 
     The quick release tie-down sub-assembly  86  comprises a body  96 , an actuator  98  which is movable relative to the body  96 , and a connector  100 . The body  96  includes a hooked portion  102  which defines an abutment surface  52  and an aperture (not visible). The actuator  98  defines a cam portion  104  and a shaft  106  extending from the cam portion  104 . The cam portion  104  includes a flared or conical shaped section  108  having a flattened side  110 . The conical section  108  defines the abutment surface  52 . The shaft  106  extends through the aperture so that a free end is joined to the connector  100 . In the illustrated embodiment, the connector  100  is configured as a ring to facilitate ease of connection to a range cords, such as ropes, cables, and straps, or connection mechanisms, such as carabiners or hooks. In use, rotation of the shaft causes the abutment surface  52  of the cam portion  104  to abut against one of the retention surfaces  20  for half of the rotation until the flattened side  110  faces towards the flange  32 , whereby the abutment surface  52  ceases to abut the retention surface  20 . The configuration of the actuator  98  in this way means that the user can readily engage or disengage the sub-assembly  86  with the slat  24  by rotating the actuator 180 degrees (or less). 
     The strap tie-down sub-assembly  88  comprises a body  112 , a resilient member  114  which is movable relative to the body  112 , and a strap  120 . The body  112  includes a hooked portion  116  which defines an abutment surface  52 , a side-wall  118  extending from the hooked portion  116  and a top section  121  which defines a slot  122  dimensioned to receive the strap  120 . In the illustrated embodiment, the top section  121  is arranged relative to the hooked portion  116  so that the top section  121  abuts the support surface  18  of the slat  24  when the abutment surface  52  abuts one of the retention surfaces  20 . It will be appreciated that the top section  120  may be alternatively configured, such as extending at an angle relative to, and not contacting, the support surface  18 . 
     The resilient member  114  is joined to the body  112  and extends towards the hooked portion  116  to define another abutment surface  52 . The abutment surface  52  of the resilient member  114  is arranged relative to the abutment surface  52  of the hooked portion  116  to cause the resilient member  114  to be resiliently deformed when the abutment surfaces  52  are arranged against the retention surfaces  20 . In the illustrated embodiment, the resilient member  114  is formed entirely from a resiliently deformable material however it will be appreciated that only part of the member  114  which defines the abutment surface  52  may be formed from the resiliently deformable material. 
     The heavy duty tie-down sub-assemblies  90 ,  92 ,  94  are variations of the same assembly, whereby common reference numerals indicate common features. Each sub assembly  90 ,  92 ,  94  includes an upper jaw  124 , a lower jaw  126  and an actuator, in the form of one or more bolts  128 . Each jaw  124 ,  126  define an abutment surface  52 . The jaws  124 ,  126  are movable relative to each other. Operating the bolt(s)  128  causes the jaws  124 ,  126  to move so that, in use, the abutment surfaces  52  urge against the retention surfaces  20  of any slat  22 ,  23 ,  24 . 
       FIG. 23  shows a ring  129  joined to the bolt  128  to allow a cord or connector mechanism to be secured to the sub-assembly  90 . 
       FIG. 24  shows the upper jaw  124  of one of the sub-assemblies  92  defining a channel  130 . The channel  130  is shaped to receive a fastener, for example, to allow a I-shaped bolt to be secured to the platform  14 , via the sub-assembly  92 . This allows an accessory which utilises a T-bolt connector, such as a bicycle or kayak carrier, to be secured to the platform  14 . 
       FIG. 24  also shows the upper jaw  124  of two other sub-assemblies  94  defining bracket  132 . In the illustrated embodiments, the bracket  132  defines an aperture  134  or slot  136  and is arranged to extend, in use, parallel or perpendicular relative to the support surface  18 . The bracket  132  allows a range of other accessories or objects, such as jacks, awnings, jerry cans, gas bottles, and the like, to be secured to the platform  14 . 
       FIG. 25  shows an alternative vehicle roof tray assembly, in the form of a platform  140 . The platform  140  shares features with the platform  14  described above, whereby common reference numerals indicate common features. 
     The platform  140  comprises cross-slats  142  which are joined to side-slats  144 . Each cross-slat  142  and side-slat  144  includes an opposed pair of the flanges  32  which define the retention surfaces  20 . This allows the platform  140  to be secured to an engaging mechanism  16 , such as any of the support bracket sub-assembly  44 , end cap sub-assembly  46 , or the tie-down sub-assemblies  86 ,  88 ,  90 ,  92 ,  94 . 
     The platform  14  is formed from a linear array of the cross-slats  144  being joined to a pair of the side-slats  144 . A corner assembly  146  is secured at each corner of the platform  140 . The corner assembly  146  includes a pair of housings (not illustrated) which are arranged on opposed sides of the platform  14  and joined to each other, typically by a plurality of fasteners (not illustrated). 
     As shown in  FIG. 28 , each side-slat  144  defines a substantially box-shaped cross-section having a junction surface  148  arranged at one side of and perpendicular to the support surface  18 . Each cross-slat  142  defines a cross-sectional profile which is identical to the slats  22 ,  23 , shown in  FIGS. 4 and 7 , As shown in  FIG. 26 , each cross-slat  142  has straight-cut ends  143  to allow abutting the cross-slat  142  against the junction surface  148 . 
       FIGS. 29 to 35  illustrate an alternative embodiment  200  of an assembly for supporting a load relative to a vehicle where the assembly  200  is configured as a tub rack  200  (also referred to as a bed rack) configured for supporting load relative to a tub  202  or bed of a utility vehicle  204  ( FIG. 30 ) or truck. Best shown in  FIG. 30 , the tub rack  200  is typically configured to be affixed to the tub  202  to support the load in an elevated position and across the tub  202 . 
     The assembly  200  includes an elongate bar  210  configured for fixing to the vehicle  204 , and at least one engaging mechanism  212  configured to be secured to the load and operable to engage the bar  210 . The elongate bar  210  has a sidewall  214  and at least one support structure  216 , the at least one support structure  216  defining a pair of opposed, diverging retention surfaces  218 . Each retention surface  218  extends away from the sidewall  214 . The, or each, engaging mechanism  212  defines a pair of opposed abutment surfaces  220  shaped to be complementary to the retention surfaces  218 . The abutment surfaces  220  are configured so that, in use, each abutment surface  220  abuts and lies against one of the retention surfaces  218 . The, or each, engaging mechanism  212  is operable to urge the abutment surfaces  220  against the retention surfaces  218  to engage the elongate bar  210 . It will be appreciated that the, or each, engaging mechanism  212  is configurable according to any of the engaging mechanisms  16  described above. 
       FIG. 29  shows the assembly  200  in isolation, and  FIG. 30  shows the assembly mounted to the tub  202  of the vehicle  204 . In the illustrated embodiment, the assembly  200  includes a pair of the elongate bars  210  configured as side bars  210  to be secured along opposed sides of the tub  202  to be spaced apart from each other. Each side bar  210  is connected to a pair of tub mount sub-assemblies  211  configured to secure the side bar  210  to the tub  202 . Best shown in  FIG. 32 , the bars  210  are shaped to be left or right sided, to be a mirror-image of each other, so that each bar  210  extends towards a centre of the vehicle, which may enhance rigidity of the assembly  200  under load. In other embodiments (not illustrated), the assembly  200  may include more or less bars  210 , including only a single bar  210 , and each bar  210  be configured for fixing between the opposed sides of the tub  202 . 
       FIGS. 29 to 32  illustrate various accessories which can be mounted to one or both of the side bars  210  by one or more of the engaging mechanisms  212 . The illustrated accessories include the platform  140  and various cross-bars  222 , such as slats  224  and roof bars  226 , mounted between the side bars  210 , tool holders  228  mounted to an underside of one of the side bars  210  to allow suspending a tool, such as shovel, from and/or alongside the side bar  210 , and universal mount structures  230  mounted to the underside of each side bar  210  to provide a robust, generic mount for securing a range of accessories to the bar  210 . Other accessories (not shown) suitable for securing to one or both of the side bars  210  include tool clamps, fuel containers, jacks, auxiliary lights, shelves, and foldable tables. It will be appreciated that this list is exemplary, not exhaustive, and that other accessories are contemplated within the scope of this disclosure. When a plurality of the cross-bars  222  are connected between the side bars  210  this forms a frame securable to the tub  202 . It will be appreciated that, in other embodiment (not illustrated), the cross-bars  222  and side bars  210  may be integrally formed to define the frame. It will also be appreciated that, in some embodiments, the elongate bar  210  is configurable as a cross-bar  222 , such as slat  225  illustrated in  FIG. 29 , to arrange the support structure  216  between the side bars  210 . 
       FIG. 30  illustrates the roof platform  140  mounted to both of the side bars  210 , and the assembly  200  mounted to the vehicle  204 . In this illustrated embodiment, the side bars  210  are shaped to arranged the roof platform  140  in an elevated position above and across the tub  202 , and below the level of the roof of the cabin (not illustrated) of the vehicle  204 . This arrangement can allow minimising wind noise caused by the roof platform  140  when driving the vehicle  204 . 
       FIG. 33  illustrates the arrangement of one of the side bars  210  and the roof platform  140 , in use, in more detail. The side bar  210  includes a support surface  232  configured to support load, in this embodiment, directly abutting an underside of the platform  140 . In this embodiment, a plurality of the engaging mechanisms  212  are secured between the platform  140  and the side bars  210  to retain the platform  140  on the bars  210 . 
     Best shown in  FIG. 32 , the side bars  210  are configured to be mounted to the tub  202  such that, in use, the support structure  216  of one bar  210  is arranged to extend towards the support structure  216  of the other bar  210 . This allows securing, via a pair of the engagement mechanisms  212 , an accessory, such as a cross-bar  222 , between the pair of side bars  210 . In some configurations, an engagement mechanism  212  is secured at each of opposed ends of the cross-bar  222  to allow mounting between the side bars  210 , such as the slat  224  illustrated in  FIG. 32 . In such configurations, a plurality of slats  224  may be arranged, by the engagement mechanisms  212 , to be flush with, or operatively below, the support surface  232  arranged at a top of each side bar  210 . When arranged to be level with the support surfaces  232 , this may allow the slats  224  and side bars  210  to form a platform to support load. In other configurations, a pair of the engagement mechanisms  212  are secured to an underside of the cross-bar  22  to allow mounting between and above, or abutting the support surface  232  of, the side bars  210 , such as the roof bar  226  illustrated in  FIGS. 29 and 31 . 
     Returning to  FIG. 31 , in the illustrated embodiment  200 , each side bar  210  defines opposed ends and is shaped to form an arch between the ends. The arch comprises a straight mid-section  234  interposed between a pair of end portions  236 , each defining a curve. This arrangement means that, in use, the mid-section  234  is arranged to be spaced from and above the tub  202  to allow supporting the load. The, or each, support structure  216  is configured to extend along at least the mid-section  234  to form an elongate rail or flange. The configuration of the, or each, support structure  216  in this way allows each accessory to be mounted at any position along at least a portion, and typically a substantial portion, of the bar  210 , which can enhance adaptability of the assembly  200 . 
     Best shown in  FIG. 35 , each side bar  210  includes a pair of the support structures  216  where a first support structure  217  extends from the sidewall in a first direction, and a second support structure  219  extends from the sidewall in a second direction arranged transverse to the first direction. In the illustrated embodiment, each side bar  210  is an extrusion and each support structure  216  is an integrally formed part of the extrusion which extends the full length of the extrusion, such that each support structure  216  is shaped to extend in the first or second direction away from the sidewall  214 . In other embodiments (not illustrated), one or more support structures  216  may be formed separately from, and secured to, the side bar  210  to allow extending from the sidewall  214 . For example, in some embodiments (not illustrated), the side bar  210  comprises a cylindrical tube and the support structures  216  are formed by one or more sleeves or collars mounted or affixed, such as by welding, along a portion of the tube. In yet other embodiments, the elongate bar  210  may be formed from sheet metal and the support structure  216  may be separately formed and joined to the bar  210 , such as by welding or mechanical fasteners. 
     Best shown in  FIGS. 33 and 34 , in the illustrated embodiment  200 , each side bar  210  is shaped such that the second direction is arranged at an angle equal to, or greater than, 90 degrees to the first direction. This means that, in use, the first direction is substantially horizontal, and the second direction is generally downwards. This allows accessories, such as the cross-bars  222 , to be mourned between the first support structures  217 , or at one side of the side bar  210 , and also allows accessories, such as the tool holders  228 , to be mounted to an underside of one of the side bars  210  to allow suspending the accessory, or another object, below the bar  210 , or otherwise within an aperture defined between the bar  210  and the vehicle  204 .  FIG. 34  illustrates one of the slats  224  secured by one of the engaging mechanisms  212  to the first support structure  217  to extend from a side of the bar  210 , and one of the universal mown structures  230  is secured by one of the engaging mechanisms  212  to the second support structure  219  to be arranged under the mid-section  234  of the bar  210 . This configuration of the side bars  210  can further enhance adaptability of the assembly  200 , allowing a wide range of accessories to be fixed to the assembly  200  in a wide range of different positions and/or orientations. 
       FIG. 35  shows both support structures  217 ,  219  may be at least partially arranged in a recess  238  defined by the sidewall  214  of the side bar  210 . The first support structure  217  is shown partly within a recess  238  defined by the sidewall  214  adjacent an operatively lower side of the support structure  217 . The second support structure  219  is substantially surrounded by a channel  239  defined by the sidewall  214 , This configuration can protect the support structures  217 ,  219  from unintended impacts, such as when securing accessories to the assembly  200 , as well as disguising the position of the support structure  217 ,  219 , which can enhance aerodynamics and/or aesthetics of the assembly  200 . 
     To assemble the platform  140 , the ends  143  of the cross-slats  142  are positioned against the side-slats  144  and welded to permanently affix the slats  142 ,  144  together. It will be appreciated that other joining techniques may be employed, such as bonding with adhesive(s) and/or connecting with mechanical fasteners, for example, to allow releasable fixing the slats  142 ,  144  together. 
     Use of the assembly  10  involves positioning the platform  14  to be spaced above the roof of the vehicle and securing any of the engaging mechanisms  16  to the retention surfaces  20  defined by one of the slats  22 ,  23 ,  24 . The load, such as cargo, is then supported on the support surface  18  of one or more of the slats  22 ,  23 ,  24  above the roof. 
     Use may involve securing an engaging mechanism  16  configured as a mounting bracket (not illustrated) to mount the platform  14  above the roof Additionally or alternatively, use may involve securing the guard rail  42 , via a plurality of support bracket sub-assemblies  44  and/or a pair of end cap sub-assemblies  46 , to one or more of the side-slats  24  and the second cross-slats  23  thereby arranging the guard rail  42  along at least one side of the platform  14 . Further additionally or alternatively, use may involve securing one or more tie-down sub-assemblies  86 ,  88 ,  90 ,  92 ,  94  to the retention surfaces  20  defined by one of the slats  22 ,  23 ,  24  to allow an object, such as a cord, strap and/or accessory, to be secured to the platform  14 . 
     The diverging configuration of the retention surfaces  20 , relative to the support surface  18 , is advantageous, as this provides a robust structure to engage the engaging mechanism  16 . In particular, the diverging arrangement of the retention surfaces  20  optimises surface area for the engaging mechanism  16  to grip and assists distributing load across the associated slat  22 ,  23 ,  24 . 
     The protruding arrangement of the retention surfaces  20  extending away from the support surface  18  minimises regions in which dust/dirt and/or moisture can collect, effectively defining a self-cleaning securement region due to air flow. This enhances ease of connecting the engaging mechanism  16  to the retention surfaces  20  and reduces the likelihood of the elongate member  14  corroding or otherwise failing due to material degradation. The protruding arrangement of the retention surfaces  20  relative to the support surface  18  also enhances manufacture as the retention surfaces  20  can be evenly coated, for example, during a powder coating process, which consequently enhances durability of the elongate member  14 . 
     The arrangement of the flange  32 , defining the retention surfaces  20 , to be spaced perpendicularly from the support surface  18  means that the engaging mechanism  16 , when engaging the retention surfaces  20 , may be arranged level with or below the support surface  18 . This arrangement is useful as this allows objects, such as cargo, to be moved along the support surface  18  unhindered by any engaging mechanism  16 . This arrangement also allows the engaging mechanism  16  to be arranged between cross-slats  22 ,  23  to optimise use of space occupied by the platform  14  and without hindering passage of cargo across the platform  14 . 
     It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.