Abstract:
A foldable deck for supporting cargo in a freight compartment is provided. The foldable deck includes a pair of deck panels connected by a double jointed hinge. The foldable deck is mounted on one of the side walls of the freight compartment and is capable of movement between a secure upright position and an extended horizontal deployed position. When the deck panels are in their deployed position they at least partially define a platform above the floor of the vehicle freight compartment. The double jointed hinge has a hinge member having a pair of pivot pins and slot pins that alternate between a deployed position and an upright position. The free end rests upon a channel or catch rail on the free wall opposite the attachment wall.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Technical Field  
         [0002]     The invention relates to intermediate deck structures for use in transport vehicles such as trucks and trailer vans, railway cars, freight containers and the like, and more particularly, to a foldable deck for use in such vehicles.  
         [0003]     2. Description of Related Art  
         [0004]     In a typical truck van, a horizontal bed or floor is provided for supporting articles being transported. Articles are placed on this bed, and depending upon the size of the articles, they may be stacked upon each other at two or more levels.  
         [0005]     In some instances, it may be impractical to stack the articles due to the weight or configuration. Where this is the case, a substantial amount of the vehicle interior is rendered unusable. For example, where the articles or containers are fragile, damage to the articles will occur if stacked to the extent that the weight of the upper articles would damage lower articles. In those instances, it is often necessary to avoid stacking or to minimize the amount of stacking.  
         [0006]     Further, to maximize volume capacity of transporting small to medium sized freight and to reduce the risk of crushing packages, shipping companies have sought to add shelves inside tractor trailers. The shelf span is from wall to wall and separates the trailer volume into spaces below and above the shelf.  
         [0007]     Some articles are also somewhat difficult to handle due to their weight and configuration. This creates problems for the individuals loading the articles on a bed. Thus, even if articles at a lower level will not be damaged when other articles are stacked thereon, stacking itself may be quite cumbersome and inefficient due to the size and weight of the articles.  
         [0008]     To facilitate loading and unloading the shelf-equipped trailer, the shelf can be divided into approximately two foot-wide sections and be designed to fold up against the wall. As cargo is loaded into the trailer from the front to the rear, each shelf section is individually folded down away from the wall and loaded with cargo. Various types of collapsible or removable intermediate deck structures have been proposed for supporting freight articles of various shapes and weights above the horizontal bed or floor of a transport van, and the like, in order to increase the load carrying ability of a van and to maximize the use of the available cubic capacity of a van. Such attempts of using intermediate decks in vehicles are discussed by U.S. Pat. Nos. 6,585,306, 6,854,400, 5,452,972, and 3,911,832.  
         [0009]     The use of collapsible or removable intermediate decks has not met with wide success, however, due to inefficiencies in the design of the decks which make them too complex, too expensive for practical purposes, or simply too inconvenient to use.  
         [0010]     As discussed in U.S. Pat. No. 6,585,306, the design of existing intermediate deck structures often consist of two deck panels, hinge mounted on opposing walls to enable storage of the deck panels vertically against the side walls. The deck panels rotate downwardly or upwardly on the hinges to a horizontal position to form a continuous section of deck, or secondary floor. Typically, this form requires a means of supporting the deck halves horizontally in a manner which both encroaches on additional usable volume for loading the freight or cargo, and interferes with that space requiring extra effort and time to load around it. Such supports include cantilever support structures, suspension chains or cables or even vertical support legs extending to the primary floor.  
         [0011]     One problem with prior art solutions is that they fail to provide the necessary ergonomic features required when changing from a secure, upright position into an extended horizontal position. For example, it is highly desirable, for safety concerns that pinch points be minimized or eliminated to prevent the accidental severing of a finger. Hence, deck panels using slidable members to engage and lock deck panels together are undesirable. Similarly, deck panels using latch-type devices that can provide a pinch point are undesirable. Further, human movement required to change the position of the deck should minimize hand and arm movements above the shoulders and below the waist to reduce or eliminate potential back injury.  
         [0012]     Consequently, there is a need for a system for supporting articles for transportation purposes. In particular, there is a need for such a support system that is of a highly efficient design whereby the deck can be economically installed in a vehicle and the system can be safely, efficiently, and ergonomically operated by a single user.  
       SUMMARY OF THE INVENTION  
       [0013]     These and other objects and advantages are met by the present invention which, in one aspect, includes a foldable deck for supporting cargo in a vehicle freight compartment having spaced apart side walls.  
         [0014]     In one aspect, the present invention includes a double jointed hinge that can be connected to a pair of deck panels. The hinge includes components that are sized to avoid pinch points as the hinge travels between upright and deployed positions.  
         [0015]     In one aspect, the foldable deck includes a first deck panel pivotally attached to a first wall connected by a double jointed hinge to a second deck panel removably secured to a second wall such that the foldable deck is capable of movement between an upright, storage position and a horizontal, deployed position. When the foldable deck is in the deployed position, it forms a secondary platform of the vehicle freight compartment. In one aspect, the foldable deck also includes a retaining magnet and/or one or more struts to help secure the foldable deck to the side wall in the upright position.  
         [0016]     Advantageously, the deck support system of the present invention supports articles more efficiently than prior art systems for transportation purposes. In particular, the deck support system is lightweight and is of highly efficient design whereby the deck can be economically installed in a vehicle, each individual intermediate deck is adequately supported, and the system can be safely and ergonomically operated by a single user.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings wherein:  
         [0018]      FIG. 1A  is a perspective view, partially cutaway, of the rearward portion of a truck trailer including an embodiment of the foldable deck in accordance with the present invention;  
         [0019]      FIG. 1B  is a side elevational view of the foldable deck in the upright position in accordance with one embodiment of the present invention;  
         [0020]      FIG. 1C  is a front elevational view of the foldable deck in the upright position in accordance with one embodiment of the present invention;  
         [0021]      FIG. 2A  is a top perspective exploded view depicting components of the deck system and double jointed hinge assembly in accordance with one embodiment of the present invention;  
         [0022]      FIG. 2B  is a bottom perspective exploded view depicting components of the deck system and double jointed hinge assembly in accordance with one embodiment of the present invention; and  
         [0023]      FIG. 2C  is a bottom perspective exploded view of some components of a portion of the double jointed hinge assembly depicting the operation of the hinge in accordance with one embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0024]     While the invention is described below with respect to one or more preferred embodiments, other embodiments are possible. The concepts disclosed herein apply equally to other systems for providing a folding support shelf for cargo areas in a storage unit including a cargo vehicle. A cargo vehicle may include any cargo vehicle, including semi-trailers, trucks, aircraft, etc. It will be readily apparent to those skilled in the art that various modifications, rearrangements, and substitutions can be made without departing from the spirit of the invention. The scope of the invention is defined by the claims appended hereto.  
         [0025]      FIG. 1A  is a perspective view, partially cutaway, of the rearward portion of a truck trailer including an embodiment of the foldable deck in accordance with the present invention. As depicted in  FIG. 1A , the foldable deck  100  is installed on a truck trailer  12 . The truck trailer  12  is enclosed by side walls  14 , a roof  16  and a floor  18 . In one aspect, the foldable deck  100  is secured to the mounting sidewall  120  by a wall mounting bracket  170  and comprises a free end  150  having a pair of catch fingers  162  for placement into a catch rail  160 . While the illustrated embodiment and the following description describe the foldable deck  100  of the present invention in conjunction with a tractor trailer, the foldable deck need not be used in conjunction with a tractor trailer, but can instead be used in conjunction with various types of freight transport vehicles or devices such as railway cars, airplanes or transport containers.  
         [0026]     As depicted in  FIG. 1A , a novel hinge assembly  200  permits the foldable deck to be easily converted from an upright, secure storage position to a horizontal, deployed position and back to an upright, secure position. A pair of hand holds  140  can help facilitate such operation. Further, although only two decks are shown (one in the upright position and one in the deployed position), the foldable deck  100  can comprise a plurality of the deployable decks along a mounting sidewall  120 . When the foldable deck  100  is in the deployed position, the system defines a secondary platform in the vehicle freight compartment. A pair of struts  180  can be attached to permit easier movement between the upright and the deployed positions.  
         [0027]      FIG. 1B  is a side elevational view of the foldable deck in the upright position in accordance with the present invention. The foldable deck  100  can be easily moved by an operator from the upright position to a deployed position and vice versa. In one embodiment, a strip  130  of steel is mounted to the mounting sidewall  120  of the freight compartment and secures a magnet disposed upon the link or hinge members of foldable deck  100  to the mounting sidewall  120  when the foldable deck  100  is in the upright position. In one embodiment, the strip  130  comprises a magnet mounted to the mounting sidewall  120  of the freight compartment and secures the foldable deck  100  to the mounting sidewall  120  when the foldable deck  100  is in the upright position. Such embodiment permits a latch-free operation further eliminating a potential pinch point and resulting in greater safety for the operator. In one aspect, the foldable deck  100  comprises a pivot end  110  that is attached to the mounting sidewall  120  by a wall mounting bracket  170 . In one embodiment, the wall mounting bracket  170  is also used to connect a strut  180  to the foldable deck. In one embodiment, the foldable deck  100  comprises one strut  180 .  
         [0028]      FIG. 1C  is a front elevational view of the foldable deck in the upright position in accordance with the present invention. In a preferred embodiment, and referring to  FIGS. 1B  and  FIGS. 1C , the foldable deck comprises two independent struts  180 , one on each side of the deck  100 , for redundancy. Two struts  180  can be used to enhance the safety, load balance, and to keep stress levels on the foldable deck  100  low. In one embodiment, a single mounting bracket  170  is used to hold struts  180  for adjacent decks. In one embodiment, the strut  180  comprises a mechanical spring strut further comprised of a nested coaxial set of springs enclosed in a steel housing. Although a pneumatic or gas strut can be used, it has been found that a mechanical spring strut has a longer lifespan and does not degrade as fast as a pneumatic strut in the tortuous, vibratory conditions that can be imparted, especially when the trailer is traveling through bumpy road conditions. In addition, loads imparted by pneumatic struts can be impacted more by temperature variations than mechanical struts. In one embodiment, one strut  180  can be designed to automatically lock as the foldable deck  100  is folded against the wall. In an alternative embodiment, the strut  180  can comprise a gas strut. When folded up against the wall  120 , the deck  100  can be held in place by a force provided by the strut(s)  180 . In one embodiment, as best depicted by  FIG. 1C , the mounting bracket  170  comprises a pin further comprising a ball  172 . The strut  180  is mounted on the ball  172  to permit slight rotation of the strut  180 . Such embodiment is advantageous as it permits the strut to swivel and rotate, thereby preventing the pin from breaking due to torsion on the joint that can easily occur from load spikes from, for example, bumpy road conditions during transport. The mounting bracket  170  can be welded to a flat length of a pre-drilled steel plate mounted on the mounting sidewall  120 .  
         [0029]     One advantage of using one or two struts  180  is that it permits the operator to raise and lower the foldable deck  100  with less lifting or pulling force. In one embodiment, no more than  25  pounds of lifting or pulling force is required by an operator to move the foldable deck  100  from the upright position to a deployed position and vice versa. This low operational lifting and pulling requirement minimizes possibility of back strains to the operator. Further, the foldable deck  100 , in accordance with one embodiment of the present invention, can be folded up or down by an operator standing to the side of the deck  100 . This reduces the possibility of injuries if the operator were required to stand directly in front of the deck  100  to either deploy or secure it upright. Another advantage provided by struts  180  is the protection offered against damaging load spikes, especially on bumpy roads. In one embodiment, the struts  180  are loaded whether the shelf is in the deployed, horizontal position or folded, upright position. The struts  180  thereby provide lifting assistance and shock absorption.  
         [0030]     In one embodiment, the deck  100  is locked against the mounting sidewall  120  by a locking strut and held in place by a retaining magnet. As the deck is folded up against the mounting sidewall  120 , the locking strut  180  lock engages at approximately 3-4 degrees from the wall  120 . At approximately 2 degrees from the wall, the retaining magnet, which can be bonded to the hinge member  230 , becomes attracted to the steel plate  130  mounted on the wall. The lower strut mounting point  172  is below and away from the shelf hinge mounting point on the wall bracket  170  such that the lifting force from the strut  180  onto the foldable deck  100  continues as the deck  100  is folded up against the wall  120 . In one embodiment, a residual “pushing” force of approximately 10 lbs is thereby provided against the wall  120  (5 lbs per strut  180 ). In one embodiment, the retaining magnet provides an additional 15 lbs of retaining force so that a total of only approximately 25 lbs of pulling force is required from the operator to pull the deck  100  away from the wall  120 . Further, the retaining magnet, by sharing the load of keeping the shelf upright, helps to protect the locking strut from being damaged when the cargo area is subjected to sudden jerks and pulls that can be common in the cargo area when the vehicle is traveling along bumpy roads. Use of a retaining magnet and locking strut in accordance with one embodiment of the present invention provides several advantages over the prior art. The deck can be securely held in the upright position without the use of latches on the mounting sidewall  120  or on the deck  100 . Further, the locking strut can automatically lock and be unlocked with a palm-operated release lever. Hence, potential pinch points produced by latches as disclosed by deck systems in the prior art are eliminated.  
         [0031]     Referring to  FIG. 1A through 1C , in the deployed position, a pair of catch fingers  162  attached to the free end  150  of the deck  100  can be easily set into a catch rail  160 . In one embodiment, the inside landing of the catch fingers  162  is about 1-½ inches wide. In one embodiment, the top of the catch rail  160  has two bends which provide a 1-½ inch horizontal landing and a vertical length to mate with the catch fingers  162 . Such design permits a 1-½ inch variance in trailer widths and is a ‘one size fits all’ design. A catch rail  160  can be mounted to the wall in the same manner as the mounting bracket  170 . In one embodiment an endcap having a length  164  can be placed in the catch rail  160  between the catch fingers  162  to prevent movement of the deck in the deployed position.  
         [0032]      FIG. 2A  is a top perspective exploded view depicting components of the deck system and double jointed hinge assembly in accordance with one embodiment of the present invention.  FIG. 2B  is a bottom perspective exploded view depicting components of the deck system and double jointed hinge assembly in accordance with one embodiment of the present invention. The folding deck  100  of the present invention comprises a pair of deck panels  102  connected by a hinge assembly  200 . In one embodiment, each deck panel  102  further comprises a male shelf extrusion  114  and a female  112  shelf extrusion. In the embodiment shown, the hinge assembly  200  comprises two end angles  210 , eight link members  220 , eight opposing hinge members  230 , three center members  240 , eight slot pins  216 , eight pivot pins  212 , four torque tubes  250  (two on each side), four torque plates  260  (two on each side), and threaded fasteners to connect the hinge members  230  to the deck panel  102 . One advantage of the double jointed hinge assembly of the present invention is that it permits the deck to fold without overlapping hinge parts. Another advantage is that it avoids pinch points common with “butt” type hinges.  
         [0033]     It should be noted that the double jointed hinge assembly  200  embodiment depicted in  FIGS. 2A and 2B  can be effectively utilized with fewer numbers of parts, depending upon the amount of width and safety desired. For example, the double jointed hinge  200 , in accordance with an alternative embodiment of the present invention, comprises two end angles  210 , two slot pins  212 , two pivot pins  216 , two opposing hinges  230 , and two link members  220 . The hinge guards  225  and pivoting hinge guards  227 , in such an embodiment, would be optional.  
         [0034]      FIG. 2C  is a bottom perspective exploded view of components of a portion of the double jointed hinge assembly depicting the operation of the hinge in accordance with one embodiment of the present invention. Referring to  FIG. 2C , a portion of the double jointed hinge comprises an end angle  210 , a link member  220 , a first pivoting hinge guard  227 , a hinge guard  225 , a second pivoting hinge guard  227 , and a hinge member  230 . The components are held together by two slot pins  216  and two pivot pins  212 . In one embodiment, the pivot pin  212  is integral with the end angle  210  and secured with snap rings in center member  240 . When the deck is in the deployed position, the slot pin  216  will be in the deployed stopped position  221  of the link member  220 . When the deck is in the upright position, the slot pin  216  will be in the upright stopped position  219  of the link member  220 . The hinge guard  225  comprises an arc slotted to permit movement of the pivot pin  212  as the slot pin  216  rotates between its deployed stopped position  221  and its upright stopped position  219 . The slot pin  216  thereby rotates concentrically about the pivot pin  212 . The pivoting hinge guard  227  has a slot pin  216  receiving area (e.g. hole) for the slot pin  216 . The pivoting hinge guard  227  thereby rotates along with the slot pin  216 . The hinge guard  225  and pivoting hinge guard  227  thereby function to prevent a pinch point that could otherwise potentially occur as the slot pin  216  rotates between the upright  219  and deployed position  221 . Although only a single slot pin  216  is depicted, each link member  220  houses two slot pins  216  and two pivot pins  212 .  
         [0035]     Referring back to  FIGS. 2A and 2B , the hinge assembly  200  connects a pair of deck panels  102  together, wherein each deck panel  102  is further comprised of a male shelf extrusion  114  and a female shelf extrusion  112 . In one embodiment, each shelf extrusion  112   114  is a low profile 1-¾″ tall hollow aluminum extrusion. In said embodiment, each shelf extrusion  112   114  is about 11.75-inches wide. The sections are joined by sliding the pair of female  112  male  114  shelf extrusions together at an extruded interlock feature. The shelf extrusions  112   114  are mirror images except for the interlock feature which is made up of a male and female shape. The unique interlock feature provides both high strength and ease of assembly of the two halves requiring no fasteners or welds. It should be pointed out that two shelf extrusions  112   114  are used solely for economical purposes. There are very few extrusion companies that are able to manufacture a product larger than  12  inches in width. Hence, one skilled in the art would recognize that such embodiment is given solely for purposes of illustration and not limitation. Deck panels  102  may or may not be comprised of separate shelf extrusions  112   114 . Further, deck panels  102  and shelf extrusions  112   114  can be provided in numerous widths and lengths depending on the size and configuration of the foldable deck  100  desired. In one embodiment, the foldable deck is comprised of two pair of shelf extrusions  112   114  connected by a hinge assembly  200 . In one embodiment, the pair of deck panels  102  comprise different lengths such that the hinge assembly  200  is off-center when the foldable deck  100  is in the deployed position. In such an embodiment, a longer length that can be associated with the pivot end  110  and a shorter length can be associated with the free end  150  and vice versa. In one embodiment, the pairs of deck panels  102  comprise substantially equal lengths. In one embodiment, a pair of shelf extrusions is approximately 23.5-inches wide and the foldable deck  100 , when in the deployed state, spans the 8-foot width of trailer interior.  
         [0036]     In one embodiment, the deck panels  102  are approximately 70% aluminum and 30% steel material to provide an optimal strength to weight ratio. In one embodiment, the deck panels  102  comprise a monocoque construction in which the skin absorbs most of the stresses to which the deck panel  102  is subjected. In one embodiment, the deck panel  102  has a height of 1.75 inches to permit the shelf to fold against the wall and maintain a less than 4 inch clearance D, as shown in  FIG. 1B . Hence, when the foldable deck  100  is deployed, the trailer cube space is maximized due to the thin section height (1.75 inches). Further when the foldable deck  100  is upright, the deck clearance D of 4 inches or less permits the deck  100  to be hidden behind the trailer rear door header frame. Such embodiment reduces the likelihood of a forklift, loader, container, or any object going in or out of the trailer interfering with the upright deck  100  during the loading or unloading of cargo. Referring back to  FIGS. 2A and 2B , in one embodiment, each shelf extrusion  112   114  features an overhang  116 . The overhang  116  can be used to hide the struts or to permit an operator to easily grasp the foldable deck.  
         [0037]     In one embodiment, the top surface of the deck panel  102  features lands and grooves, similar to that of a stadium bleacher surface. This type of surface feature is smooth on packages yet slip resistant. Further, the land and groove design channels water giving the deck panel  102  an overall resistance to slipping while walking on it.  
         [0038]     As previously stated, the hinge assembly  200  connects a pair of deck panels  102  together. Specifically, the hinge members  230  assemble into the hollow cavity of the shelf extrusions  112   114 . In one embodiment, two grade 8 button head screws (e.g. hinge screws) per hinge member  230  are threaded, from the bottom, into flush mounted barrel nuts which connect the hinge members  230  into the shelf extrusions  112   114 . Thin stainless steel shim washers keep the low profile screw head as close to the top of the shelf extrusion surface to prevent package hang-ups.  
         [0039]     Because the hinge members  230  are hollow, there is an increased tendency for collapse as the hinge screws are tightened. Consequently, a torque tube  250  can be inserted into a cavity in the hinge members  230 . In one embodiment, the torque tube  250  is comprised predominantly of steel. As the hinge screws are tightened, the hinge member  230  to torque tube  250  connection becomes more solid. The moment from the hinge assembly can then be transmitted through the hinge members  230  to the torque tube  250 . The moment from the hinge assembly travels laterally along the torque tube  250  and through square holes  255  in the vertical walls of the deck panel  102 . A large portion of the bending strength in the shelf extrusions  112   114  (e.g. deck panel  102 ) is due to the vertical walls, which are comprised of two outer walls and one internal rib per shelf extrusion  112   114 .  
         [0040]     In one embodiment, the torque tube protrudes slightly from holes  255  outside shelf extrusion  112   114  vertical walls where a torque plate  260  attaches. In one embodiment, the torque plate  260  is comprised predominantly of steel. In one embodiment, the torque tube  250  is a ¾ inch square steel tube 20.25 inches long and passes through the cavities of four hinge members  230  on each side of the hinge assembly  200 . The torque tube thereby fits into a square slot in the torque plate  260  and transfers the moment through the square slot. A weld is applied to the slot during final assembly. In one embodiment, the torque tube  250  fits snugly through a ¾″ hinge member cavity and through a portion  255  of the shelf extrusion and welded to the torque plate  260 . The moment from the torque tube  250  can travel primarily through the weld to the torque plates  260 , and to the holes  255  in the shelf extrusion  112   114  internal ribs. In one embodiment, the torque plates  260  are fastened to the outside of the outer vertical walls of the deck panel  102  with rivets. The torque plate  260  can convert the moment to a distributed shear into the rivets that attach the torque plate  260  to the outer vertical shelf extrusion  112   114 , or deck panel  102  walls. Other attachment means can also be used.  
         [0041]     Hence, in one embodiment, fasteners that attach the hinge member  230  to the deck panel  102  fasten the upper and lower skins of the deck panel  102  to the hinge member  230  and clamp the hinge member  230  to the torque tubes  250 . Further, the torque tube  250  prevents the hinge members  230  from collapsing when the fasteners or hinge screws are tightened, and transmit the moment from the hinge assembly  200  to the shelf vertical walls of the deck panel  102 .  
         [0042]     In one embodiment, stainless steel shim washers are used underneath the screw head fasteners to inhibit galvanic corrosion from the steel screw to the aluminum deck panel  102 . In one embodiment, steel nuts can be plated to provide an electrolysis barrier. In one embodiment, barrel nuts having relatively wide and thin surfaces on the outside can be used and mounted through the top of the deck panel  102  so that packages may slide across the top of the deck panel  102  without being damaged. The unique hinge assembly  200  design lies flat thereby minimizing protruding features. Consequently, uneven surfaces that may cause an operator standing on the deck to potentially trip are minimized.  
         [0043]     In one embodiment, the gaps between the moving parts of the hinge assembly  200  including the distance between opposing hinge members  230  and between link members  220  are a minimum of at least one inch. For example, the gap between the opposing hinge members  230  (e.g. hinge member gap) and a gap between the link members  220  (e.g. link member gap) are preferably more than one inch. Such embodiment is advantageous as such distance helps to prevent serious injury to an operator&#39;s fingers and eliminates a potential pinch point. Similarly, in one embodiment, a one-inch gap exists between adjacent foldable decks  100 . The upper gap limits (link member gap, hinge gap, and foldable decks gap) can be influenced by the size required to prevent packages from slipping through the gaps. Hence, in one embodiment, such gaps are less than about 1.5 inches.  
         [0044]     As previously stated, the foldable deck  100  comprises one or more independent struts  180 . As previously noted, although in one embodiment the shelf extrusions are approximately 70% aluminum and 30% steel, it should be noted that the force from each strut  180  helps direct the load through parts made predominantly of steel and relieves load imparted on the deck panel  102 , thereby increasing the life of the shelf system. Referring to FIGS.  1 A-B, the strut force travels through the lower strut mounting bolt to the mounting bracket  170 , to the shelf mounting pin about which the foldable deck  100  pivots, to the shelf end bracket, up through the hollow cavity of the pivot-side deck panel  102 , out of the shelf extrusion  112   114  through a side hole to the upper strut mounting bolt. This load path is a closed loop through materials made predominantly of steel material. The shelf end bracket is the primary load bearing component and although highly loaded in tension, provides cradling support to the foldable deck, thereby minimizing the load the foldable deck receives from the struts.  
         [0045]     While this invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.