Abstract:
A modifiable rack system can be connected to a vehicle such as a truck or a tractor, and includes a receptacle for holding a variety of items including materials and equipment. The rack system includes a variety of add-ons for organizing and retaining equipment, and a hinged tail gate for easy access. The rack system includes a trailer hitch so a rolling trailer, or the like, can be daisy-chained off the back end. Wheels can be mounted to the rack system so the rack system can used as a rolling cart. The rack system is able to withstand large forces during use because of a tow support spine, and associated structures, which impart tremendous strength.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from the U.S. provisional patent application entitled MODIFIABLE RACK SYSTEM, which was filed on Oct. 17, 2013, and assigned the Ser. No. 61/892,030. 
    
    
     BACKGROUND OF THE INVENTION 
     Field 
     The present invention relates to devices for the transportation and storage of various implements, and more specifically, to a multi-functional rack that is configured for connection to a vehicle, for free standing, and/or for rolling. 
     Related Art 
     There are a variety of devices for storing and/or transporting implements such as tools, lawn equipment, farm apparatus and so forth. These devices include simple trailers that connect to road vehicles (for example the CARRY-ON TRAILER 5-ft×8-ft Wire Mesh Utility Trailer with Ramp Gate); trailers that connect to tractors (for example the AGRI-FAB Light Duty Dump Cart); vehicle mounted tool racks (for example TRADESMAN 48″ Steel Mid-Size Flush Mount Truck Box); and rolling toolboxes (for example CH ELLIS Rolling Tool Case Tele Handle with Bumpers and Wheels). However, all of these devices have limitations. 
     Trailers used with road vehicles are typically large and cumbersome, and therefore are limited in where they can be used. The fully enclosed styles are secure, but it is difficult to access the contents inside. Alternatively, the open styles, which typically include a platform floor and partial vertical walls, provide accessibility, but must be secured when not in use because the contents are vulnerable to theft and the environment. Also, because road vehicle trailers connect to the vehicle&#39;s tow ball, the vehicle is limited to towing just the trailer. Trailers that connect to tractors typically have the same limitations as road vehicle trailers. Vehicle mounted tool racks are typically lockable, and therefore secure. In addition, because they are mounted in the back of a truck, they don&#39;t occupy the trailer ball and the vehicle may tow. However, vehicle mounted tool racks are limited in space, and simply too small to hold certain equipment including most landscaping items with long handles. Moreover, it isn&#39;t practical to remove the vehicle mounted box and bring it to a location, for example inside a dwelling, in order to have all the tools readily available. Also, because the items are typically piled up in these boxes, accessibility is limited. Finally, while rolling toolboxes are useful insofar as they can easily be moved from one place to another, for example from one section of the garage to another, they are not easily transported by vehicle. Also, they are limited in storage space and can&#39;t reasonably store larger items such as landscaping tools. 
     As can be seen, there is a need for a system of storing and transporting tools, and in particular a modifiable rack system that is configured for connection to a vehicle, for free standing, and/or for rolling. It is desirable that this rack system provides free access to the implements that it is holding, is relatively compact, yet can secure both large and small items. It is desirable that this rack system can be towed, but allows for towing additional items. It is desirable that this rack system can be moved from one place to another by towing, or by rolling, and that it lends itself to a use as a semi-stationary system when not being transported. It is also desirable that the system is durable, and can withstand substantial dynamic load weight forces, up to 600 lbs., during use and transport. It is also desirable that the system is compatible for connection to 3 point hitch assemblies, or conventional vehicle trailer hitches. 
     SUMMARY OF THE INVENTION 
     A modifiable rack system can be connected to a vehicle such as a truck or a tractor such that the modifiable rack system protrudes from the back of the vehicle, but does not touch the ground. The rack system includes a trailer hitch on the back end so that a trailer can be “daisy chained” onto the end of the modifiable rack. In this manner there would be the vehicle connected to the modifiable rack connected to the trailer, with the modifiable rack in the center and not touching the ground. 
     The rack includes a receptacle for holding a variety of items including materials and equipment, a variety of add-ons for organizing and retaining equipment, and a hinged tail gate for easy access. Attachable rail tubes provide additional stability to the rack as well as additional attachment sites for add-ons. 
     Wheels can be mounted to the rack system so the rack system can used as a rolling cart. More specifically, it is possible to mount the wheels on the rack system while the rack system is engaged to a vehicle, and off the ground. In this manner the wheeled rack can be lowered to the ground and rolled to the desired location for use or storage. 
     The rack system is subjected to enormous forces while in use because it holds heavy equipment, bounces behind a moving vehicle, and is not supported underneath by wheels or such. However, the rack system is able to withstand these forces largely due to a tow support spine along the bottom side of the floor of the receptacle. The tow support spine is reinforced by a plurality of tow spine supports that extend perpendicularly from the spine, and a plurality of lift arm connectors that are positioned in parallel and equidistant from the spine on either side. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an embodiment of the invention; 
         FIG. 2  is a side perspective view of the same embodiment of the invention from  FIG. 1 ; 
         FIG. 3  is a back perspective view of the same embodiment of the invention from  FIG. 1 ; 
         FIG. 4  is a top perspective view of the same embodiment of the invention from  FIG. 1 ; 
         FIG. 5  is a bottom perspective view of the same embodiment of the invention from  FIG. 1 ; 
         FIG. 6  is an alternate bottom perspective view of the same embodiment of the invention from  FIG. 1 ; 
         FIG. 7  depicts an embodiment of the invention in use, with tools attached to main frame using removable rack accessories, and with lumber carrier accessory shown in the retracted position; 
         FIG. 8  depicts the same embodiment of the invention from  FIG. 7  in use, with tools attached to main frame using removable rack accessories, and with lumber carrier accessory shown in the engaged position. 
         FIG. 9  is a close-up view of the embodiment of the invention from  FIG. 7  depicting the lumber carrier accessory attached to the main frame in the engaged position; 
         FIG. 10  is a close-up view of the embodiment of the invention from  FIG. 7  depicting a strap tool bracket attached to the main frame, and the lumber carrier accessory attached in the retracted position; 
         FIG. 11  is a close-up view of the embodiment of the invention from  FIG. 7  depicting a J hook bracket attached to the main frame, in conjunction with strap tool brackets in use and the lumber carrier accessory in the retracted position; 
         FIG. 12  is a close-up view of the embodiment of the invention from  FIG. 7  depicting a ring tool bracket attached to the main frame, in conjunction with strap tool brackets and a J hook bracket; 
         FIG. 13  depicts a front perspective view of the same embodiment of the invention from  FIG. 1 , with the pivoting tail gate in the open position; 
         FIG. 14  depicts a side perspective view of the same embodiment of the invention from  FIG. 1 , with the pivoting tail gate in the open position; 
         FIG. 15  depicts a first alternative embodiment of the present invention; 
         FIG. 16  depicts a perspective view of the same embodiment of the invention from  FIG. 1 , with wheels attached; 
         FIG. 17  is a close-up view of the embodiment of the invention from  FIG. 16  depicting the wheels and associated attachment means; 
         FIG. 18  depicts a perspective view of the embodiment of the device from  FIG. 1 , with a yellow core, engaged with a tractor; 
         FIG. 19  depicts another perspective view of the embodiment of the device from  FIG. 1 , with a yellow frame bar, engaged with a tractor; 
         FIG. 20  depicts a perspective view of the alternate embodiment of the device from  FIG. 15 , with a short yellow frame bar, engaged with a tractor; 
         FIGS. 21-43  depict various embodiments both with and without a 3 point hitch assembly but having structural features such as latches on tail gate, and 4 separate legs; 
         FIGS. 44-46  depict a “daisy chain”; 
         FIGS. 47-48  depict an embodiment having four separate legs; 
         FIG. 49  depicts a rack assembly including a chain saw holder add-on; 
         FIGS. 50-52  depict the rack system engaged with a tractor&#39;s 3 point hitch assembly; 
         FIGS. 53-66  present the results of a Loading Analysis Study; and 
         FIGS. 67-68  depict exploded views of the main frame of the rack assembly; 
         FIGS. 69-72  depict various views of the back panel of the bed; 
         FIGS. 73-76  depict various views of the hinge tab; 
         FIGS. 77-80  depict various views of the rack bed floor; 
         FIGS. 81-84  depict various views of the right-side lift arm; 
         FIGS. 85-88  depict various views of the left-side lift arm connector; 
         FIGS. 89-92  depict various views of the side bin tool bracket; 
         FIGS. 93-97  depict various views of the strap tool bracket; 
         FIGS. 98-101  depict various views of the ring tool bracket; 
         FIGS. 102-107  depict various views of the chain saw holder; 
         FIGS. 108-111  depict various views of the lumber rack bracket hinge; 
         FIGS. 112-115  depict various views of the lumber rack tool bracket; 
         FIGS. 116-117  depict various views of the replacement tube insert; 
         FIGS. 118-126  depict various views of the tail gate; 
         FIGS. 127-130  depict various views of the tail gate slide latch; 
         FIGS. 131-134  depict various views of the top link connector; 
         FIGS. 135-158  depict various views of the support spine with 3-point hitch assembly; 
         FIGS. 159-170  depict various views of the lateral tube; 
         FIGS. 171-180  depict various views of the tool bracket clamp assembly; 
         FIGS. 181-191  depict various views of the long tool bracket; 
         FIGS. 192-200  depict various views of the wheel legs; 
         FIGS. 201-214  depict various views of the wheel assembly bracket; 
         FIGS. 215-230  depict various views of the top link connector including hold for weight bracket; 
         FIGS. 231-240  depict various views of the hinge pin and plate; 
         FIGS. 241-247  depict various views of the rack bed right side; 
         FIGS. 248-254  depict various views of the rack bed left side; 
         FIGS. 255-266  depict various views of the weighted cross beam accessory; 
         FIGS. 267-278  depict various views of the A Rib right side; and 
         FIGS. 279-290  depict various views of the A Rib left side. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
     As used herein, the following terms shall refer to the stated structures among the various FIGS: 
       10 —Rack assembly; 
       11 —Upper portion; 
       12 —Bottom portion; 
       13 —Receptacle; 
       14 —Latch; 
       15 —Tail gate; 
       16 —Slide; 
       17 —Hinge; 
       18 —Bed side; 
       19 —Bed back; 
       20 —Bed floor; 
       30 —Trailer hitch; 
       31 —Horizontal top link connector; 
       32 —Lift arm connector; 
       33 —Vertical top link connector; 
       34 —Tow spine support; 
       35 —Tow spine 
       40 —Rail tube; 
       41 —Short rib tube; 
       42 —Cross bar; 
       50 —Wheel; 
       51 —Caster; 
       52 —Legs; 
       53 —Wheel mount plate; 
       54 —Leg sleeve; 
       55 —Aperture 
       60 —Lumber rack tool bracket; 
       61 —Ring tool bracket; 
       62 —Side bin bracket; 
       63 —Strap tool bracket; 
       64 —J hook bracket; 
       65 —Chainsaw holder; 
       110 —Alternative rack assembly; and 
       140 —Alternative rail tube. 
     Referring to  FIG. 1 , a preferred embodiment of rack assembly  10  generally includes upper portion  11  having two curved rail tubes  40  extending to bottom portion  12 . Bottom portion  12  includes receptacle  13 , including tail gate  15 , two bed sides  18  ( FIG. 2  shows one), bed back  19  ( FIG. 3 ), and bed floor  20  ( FIG. 4 ). As best shown in  FIG. 6 , tail gate  15  is connected to bed floor  20  at hinges  17 .  FIG. 41  depicts tailgate attached to side panels with spring pins for easy removal. Tail gate  15  is preferably a continuous and planar surface with upper surface of bed floor  20  when tail gate  15  is in opened position ( FIG. 13 ). Tail gate  15  can released from vertical position to rest at horizontal position, and be locked at vertical position, by slides  16 . Alternatively, tail gate  15  can be released and locked by latches  14 , as shown in  FIG. 21 . Curved rail tubes  40  are preferably constructed of square tubing having approximately 1¼ to 2 inch width, and preferably approximately 1/16 inch wall thickness. Wall and floor structures of receptacle  13  are preferably constructed of between 12 and 16 gauge, and preferably 13 gauge, steel. It is preferred to use cold rolled steel in the construction of rack assembly  10 , in order to gain strength and durability. Also, it may be desirable to corrugate panels such as tail gate  15  and bed back  19  in order to gain more rigidity under load. 
     As shown in  FIG. 2 , rack assembly  10  can include an assembly which is compatible with the 3 point hitch system found in many tractors. This assembly includes horizontal top link connector  31 , vertical top link connector  33 , and lift arm connector  32 . As best shown in  FIG. 6 , horizontal top link connector  31  and vertical top link connector  33  comprise one unitary “L-shaped” piece, with the former forming the short part of the “L”, and the latter forming the long part of the “L”.  FIGS. 50-52  depict a tractor mounted with rack assembly  10 . However, it should be understood that rack assembly  10  can be used without the 3 point hitch assembly, as shown in  FIGS. 25 &amp; 27 . In this embodiment rack assembly  10  plugs directly into a conventional receiver, such as that found on a pickup truck. 
     Rack assembly  10  can be engaged with a variety of vehicles including automobiles, trucks, vans, ATV&#39;s, UTV&#39;s, golf carts, tractors, or others that can accept a 2″ receiver hook up and/or that have a 3 point hitch. On the opposite side of horizontal top link connector  31  is trailer hitch  30  ( FIG. 5 ), thereby providing an attachment point for an additional trailer. Having two connection points, for example trailer hitch  30  on one side and 3 point hitch assembly on the other side, permits “daisy chaining” of trailers. Alternatively, “daisy chaining” can be without 3 point hitch assembly, as depicted in  FIGS. 44-46 . It is desirable that trailer hitch  30  includes a square receiver opening of 1.25 inches (for Class I/II towing), or 2 inches (for Class III/IV/V towing). Class IV/V receivers, in 2.5 inches, are also possible. In this manner a user tow items such as a seed spreader, log splitter, trailers for personal watercraft, and so forth. 
     As would be understood by those in the art, rack assembly  10  must withstand a tremendous amount of force when used with a vehicle. For one, rack assembly  10  extends outwardly from a vehicle, without being supported underneath. Additionally, a trailer may be connected rearwardly. There is also the weight of rack assembly  10  itself (approximately 170 pounds, depending on the configuration), plus all the implements stored on and inside the device. Finally, the rack assembly  10  is subjected to bouncing when attached to a moving tractor or other vehicle. Rack assembly  10  includes various structures which enable the device to withstand these forces. Of particular importance is tow spine  35 , which unifies trailer hitch  30  and horizontal top link connector  31 . In addition, a plurality of tow spine supports  34 , extending substantially perpendicularly from tow spine  35 , also provide structural integrity by strongly reinforcing bed floor  20 . This is further strengthened by lift arm connectors  32 , as shown in  FIG. 6 , and the use of a 3 point hitch where compatible. 
     Tow spine  35  performs the majority of the work in terms of load bearing and resistance to deformation of the structure when under different loading scenarios. While most of the assembly could be delivered as a flat packed bolt together kit, the tow spine  35  is a welded, heavier gauge steel, providing a rigid foundation for the rest of the rack, in addition to the modular hitch features. The tow spine&#39;s metal thickness can range from ⅛ inch to ¼ inch. 
     Regarding  FIGS. 56A and 56B , two acceptable loading scenarios are demonstrated.  FIG. 56A  shows a loading scenario with a 480 lbf evenly distributed in the center of the rack, bringing the total static weight to 600 lbf.  FIG. 56B  shows a loading scenario with a 320 (calculated) load placed asymmetrically all on one side up to the maximum the rack can handle. 
       FIGS. 53-66  set forth Finite Element Analysis results. Although this analysis was conducted with an earlier rack design, consisting of mostly square tubing, the focus was on determining the strength of the spine component. Accordingly, much of the data is relevant to the present invention. 
     Regarding  FIG. 54 , for the finite element analysis, the rack weight was configured for 2″ square receiver, approximately 120 lbs, and the analysis was based on 1020 Cold Rolled Steel material properties. 
     Regarding  FIG. 55 , the following support specifications are preferred: 
     Support (Receiver and Hitch) Specifications. 
                                                 3 Point Hitch (category 0), 12″ behind LP   450 lbf (JD)           3 Point Hitch (category 1), 24″ behind LP   680-1450 lbf (JD)           2″ Square Receiver (class III, standard)   600 lbf (TW)           1¼″ Square Receiver (class I) *   200 lbf (TW)           1¼″ Square Receiver (class II)   300 lbf (TW)                       Reasonable design limit for standard configuration (2″ square receiver) is 600 lbf (static). This would be an acceptable load for all class 3 rated receivers and receivers on class 1 or higher 3 point hitches.           * Possible to design 1¼″ configuration such that system only fits class II receivers            
Regarding  FIG. 57 , a spine component designed with ⅛″ walls, appr. 16 lbs, is depicted with a symmetric loading of 1200 lbf total load (120 lbf plus 480 lbf payload, 2×FoS), showing that the highest stresses are at the square tube where it exits the receiver, but the stresses should not cause yielding of rack.
 
     Regarding  FIG. 58 , a spine component is depicted with a symmetric loading, showing that at maximum load and 2× gravity (driving over a bump), the point furthest from the receiver will flex downward approx. 0.144″. 
       FIG. 59  depicts maximum payloads of different materials, evenly distributed.  FIG. 59A  depicts 12 concrete blocks evenly distributed at 30-40 lbf each.  FIG. 59B  depicts 12 cubic feet of Green Oak at 40 lbf/ft 3  evenly distributed (other woods weigh less, so larger volume could be carried.)  FIG. 59C  depicts 6 bags of cement evenly distributed at 80 lbf each.  FIG. 59D  depicts one 55 gallon drum filled with water at 500 lbf (slightly over max) evenly distributed. 
       FIG. 61  depicts 320 lbf asymmetrically loaded at extremes of ribs and 120 lbf representing weight of rack (2×FoS for a total of 880 lbf). System has highest stresses where 2″ tube exits hitch receiver but should not yield. Additional strength can be gained (if needed) by using 3/16″ wall tubing. 
       FIG. 62 , depicts 640 lbf asymmetrically loaded at extremes of ribs (2×FoS) and 240 lbf representing weight of rack (2×FoS). Deflection at worst position is approximately 0.25″ vertically. 
       FIG. 63  depicts maximum payloads equal to 320 lbf (static), unevenly distributed. Although it is difficult to predict how the rack will be loaded, the rack will handle 4 bags of cement or 8 concrete blocks when subjected to 2 times G (gravity). 
     As can be seen in  FIGS. 7-12, and 29-34 , a variety of add-on brackets and holders may be added to rack assembly  10  in order to customize the device according to the needs of the user. Examples of add-ons include lumber bracket  60 , ring tool bracket  61 , side bin bracket  62 , strap tool bracket  63 , J hook bracket  64 , and chain saw holder (unnumbered in  FIGS. 29, 30, 31 and 34 ). As shown in  FIG. 7 , cross bar  42  may also be used, which adds additional structural integrity to the device and provides an attachment site for additional add-ons. 
       FIG. 15  depicts alternative rack assembly  110 , having alternative rail tube  140 , which is substantially rectangular in shape. 
     One advantage of rack assembly  10  is that it may be removed from a vehicle and used as a semi-stationary storage device ( FIG. 14 ), or as a tool cart ( FIG. 16 ). As shown in  FIG. 17 , rolling functionality is provided for by connecting one wheel mount plate  53  to each bed side  18 . Each wheel mount plate  53  includes a pair of hollow leg sleeves  54  which releasably receive legs  52 . Vertical displacement of rack assembly  10  can be changed by adjusting position of legs  52  within leg sleeves  54 , then securing with pins (not shown) that pass through apertures  55 . In this manner rack assembly  10  can be rolled on wheels  50  from one location to another. This functionality may be particularly helpful when engaging and disengaging rack assembly  10  and vehicle. By way of example, a user can roll fully loaded rack assembly  10  to the vicinity of a vehicle&#39;s hitch, connect the rack to the vehicle, remove wheel mount plate  53 , and use the vehicle-mounted rack in the ordinary manner. When it is desirable to remove the rack from the vehicle the user can attach mount plates  53 , and then roll the rack (fully loaded) to a desired location. In this manner a user adjusts leg lengths once, and then simply attaches the wheel mount plates (and connected legs) as desired. 
     In another embodiment, depicted in  FIGS. 38-40, 47 and 48  there are four individual legs that are mounted. This embodiment is used in the manner described, except it is necessary to attach legs one at a time. 
     Another important structure of the present invention is the suitcase weight bracket accessory of  FIGS. 255-266 . This bracket holds suitcase weights (not shown) for counter weight. More specifically,  FIGS. 255-266  depict a mounting bar that attaches to the 3 pt riser arm, and is used to hang counterweights. 
     It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. By way of example the rack assembly can be modified for other specific uses such as transporting cargo, tailgating, camping, and hunting. Add-ons can secure items such as hunting rifles, bows, bird cages, fishing gear, fishing poles and so forth. Also accessories such as work tables, table saw work surfaces, and chop saw work surfaces can be used with the rack assembly&#39;s 2 inch receiver. All ranges set forth herein include increments there between; “approximate” and the like mean+/−10%