Abstract:
A wheel-less cargo carrier or dolly has multiple telescoping or expandable support beams that can remain attached to a vehicle in a retracted configuration when not in use. For use of the wheel-less cargo carrier, the beams are extended and engaged with a floor, fence, or other structural portion of the wheel-less cargo carrier. Telescoping beams can include multiple rails where smaller rails nest within larger rails and slide relative to the larger rails as the beams are being extended or collapsed. The rails can share a common top surface, so that a base or floor of the wheel-less cargo carrier lies on a flat support structure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent document claims benefit of the earlier filing date of U.S. provisional patent application 61/077,796, filed Jul. 2, 2008, which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Many people have an occasional need to transport bulky objects that do not easily fit in their car. Even those with sport utility vehicles, vans, and station wagons, which have more interior space than many other non-commercial vehicles, are unable to easily transport tall or large objects. Also, when an object would fit in the interior of the vehicle, it is sometimes undesirable to have messy or noxious items sharing the interior space with passengers. A light truck can fulfill many people&#39;s cargo transportation needs, but keeping a light truck may not be practical for many because of the cost and space needed for a second vehicle. Conventional trailers, which can be towed behind a vehicle, may also be impractical because of the cost, the need for government registration, and the space required to keep a trailer. Wheeled trailers may also be undesirable because of maneuvering difficulties for occasional users. 
         [0003]    Wheel-less cargo carriers such as bike racks are being used to meet some cargo transportation needs. Prior wheel-less cargo carriers generally have a tongue that fits into a standard trailer hitch and are suspended as a cantilever supported by the trailer hitch and the length of the tongue within the hitch. The current systems have obvious structural limitations. In particular, the weight that can be supported depends on strength and length of the tongue and hitch. Additionally, a conventional trailer hitch with a single tongue has a single support that can only withstand minimal torques about the axis of the hitch. As a result, conventional wheel-less cargo carriers are small and have limited weight capacity. Further, although current wheel-less cargo carriers are relatively compact when compared to conventional trailers, they still require storage space when removed from a vehicle. 
       SUMMARY 
       [0004]    In accordance with an aspect of the invention, a wheel-less cargo carrier or dolly has multiple telescoping or expandable support beams that can remain attached to a vehicle in a retracted configuration when not in use. For use of the wheel-less cargo carrier, the beams are extended and engaged with a floor, base plate, cage panels, or other structural portion of the wheel-less cargo carrier. Telescoping beams can include multiple sliding rails where smaller rails nest within larger rails and slide relative to the larger rails as the beams are being extended or retracted. The rails can share a substantially level common top surface, so that a floor of the wheel-less cargo carrier lies on a flat supporting base. In generally, a floor plate and/or cage panels can be bolted on the sliding rails to provide a rigid structure. 
         [0005]    In accordance with a further aspect of the invention, a floor of a wheel-less cargo carrier can include hinge-linked panels that may be removed or left in place in a folded configuration when the wheel-less cargo carrier is not in use. The hinge-linked plates can then be unfolded and bolted or otherwise attached to the extendable beams during use of the wheel-less cargo carrier. 
         [0006]    One specific embodiment of the invention is a wheel-less cargo carrier including multiple telescoping support beams that attach to a vehicle. A floor on the telescoping beams carries cargo. 
         [0007]    Another specific embodiment of the invention is a method for carrying cargo. The method includes: mounting telescoping beams on a vehicle; extending the beams to a first length to provide a base on which cargo is carried by the vehicle; and retracting the beams when cargo is not being carried. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIGS. 1A and 1B  show extended configurations of wheel-less cargo carriers respectively using an under-body mounting system and an in-trunk mounting system in accordance with alternative embodiments of the invention. 
           [0009]      FIGS. 1C and 1D  respectively show the wheel-less cargo carriers of  FIGS. 1A and 1B  when in a retracted configuration. 
           [0010]      FIGS. 1E and 1F  show a wheel-less cargo carrier in accordance with an embodiment of the invention in which telescoping support beams form part of a drawer built into a vehicle. 
           [0011]      FIG. 2  shows a perspective view of a telescoping beam in accordance with an embodiment of the invention when sliding rails are in a retracted position. 
           [0012]      FIGS. 3A ,  3 B, and  3 C show separate sliding rails employed in the telescoping beam of  FIG. 2 . 
           [0013]      FIG. 4  illustrates the use of rollers in the support beam of  FIG. 2 . 
           [0014]      FIGS. 5A ,  5 B, and  5 C show a support base structure including extendable beams respectively with different degrees of extension. 
           [0015]      FIG. 6  shows a portion of a floor in accordance with an embodiment of the invention using folding floor sections linked by piano hinges. 
       
    
    
       [0016]    Use of the same reference symbols in different figures indicates similar or identical items. 
       DETAILED DESCRIPTION 
       [0017]    In accordance with an aspect of the invention, a wheel-less cargo carrier can employ multiple telescoping support beams that are put in a retracted position and left attached to a vehicle when not in use. The support beams are extended when forming a support base for carrying cargo in the wheel-less cargo carrier. A floor attaches to the support base when the cargo carrier is in use, and to further reduce storage space, the floor can have an accordion-like folded structure that may remain attached to the vehicle when not is use or may be removed and stored in the vehicle or elsewhere. Additionally, a fence, basket, cage, or other cargo retaining structure with or without a gate or ramp may be attached to the support base and/or floor. The cargo carrier can be an after market addition to a vehicle or a factory built feature of the vehicle. A factory built cargo carrier can more easily be included in a drawer-like installation in which the telescoping support beams extend when a drawer is pulled out and hidden when the drawer is closed. 
         [0018]      FIG. 1A  shows a system  100  including a vehicle  110  with a wheel-less cargo carrier  120  in accordance with an exemplary embodiment of the invention. Vehicle  110  can be any type of automobile including but not limited to a passenger car, a sports utility vehicle, a van, or a truck of any make or model. In the illustrated embodiment, wheel-less cargo carrier  120  is an after market product that can be installed on a vehicle after manufacture of vehicle  110 , and vehicle  110  does not require any special features, other than sufficient space and a suitably strong structure for attachment of cargo carrier  120  to vehicle  110 . 
         [0019]    Wheel-less cargo carrier  120  includes support beams  122 , and a cargo cage  124 . Support beams  122  are attached to vehicle  110  using a mounting system  126 , which in the embodiment of  FIG. 1A  attaches under the body of vehicle  110 . Mounting system  126  may include steel mounting structure (e.g., 3-inch square steel tubing) that attaches to support beams  122  and the frame of vehicle  110  or to one or more suitably strong structural members of the body of vehicle  110 . In general, mounting system  126  will have a design that is adapted to the particular model of vehicle  110  and can attach to vehicle  110  in the same manner as the attachments of trailer hitches, which are well known in the art. Mounting system  126  may include welds, bolts, or other fasteners that hold support beams  122  in place and are not casually removed. Accordingly, support beams  122  effectively remain a permanent feature of vehicle  110 . 
         [0020]    Cargo cage  124  generally includes a floor that rests on and attaches to support beams  122  and a fence (e.g., a hinge-linked basket or cage) with or without gate or ramp structures. More specifically, cargo cage  120  optionally includes a gate or ramp that is opened for loading of cargo onto the floor of cargo cage  124  and may be closed so that the gate or ramp helps keep cargo within a perimeter of cargo cage  120 . Cargo cage  124  can be made of any suitably strong material but is preferably made of a light weight metal such as an aluminum alloy or a durable plastic or composite material that that may be reinforced with metal or other material. Cargo cage  124  may also include reflectors, tail lights, or other safety features. Preferably, cargo cage  124  is fully or partially removable from support beams  122  and may be folded up into a compact unit for storage inside or outside vehicle  110 . As described further below, a portion of cargo cage  124 , e.g., the floor, may be left attached to support beams  122  when the fence or basket structure is removed. 
         [0021]      FIG. 1B  shows an alternative system  100 ′ in which vehicle  110  uses wheel-less cargo carrier  120 . Vehicle  110  and wheel-less cargo carrier  120  in  FIG. 1B  can be substantially the same as described above with reference to  FIG. 1A  with the exception that a mounting system  126 ′ of  FIG. 1B  attaches support beams  122  in the trunk or other interior space of vehicle  110 . Accordingly, the body of vehicle  110  in  FIG. 1B  may require minor modification to add openings  128  through which support beams  122  can extend from vehicle  110 . Opening  128  may be equipped with a flexible boot (not shown) that seals around support beams  122 . Alternatively, if support beams  122  can be fully retracted into vehicle  110 , rubber caps or other structures may seal openings  128  against the weather when wheel-less cargo carrier  120  is not in use. In another embodiment, which is well suited for factory installation, a drawer face attached to the ends of support beams  122  matches the contours and color of the rest of the body of vehicle  110  and hides beams  122  when the beams are retracted (i.e., when the drawer is closed.) 
         [0022]    An advantage of system  100 ′ is that cargo cage  120  may be positioned closer to the back wheels of vehicle  110 , for example, have an edge overlapping the back bumper of vehicle  110 , reducing the lever arm on which the weight of cargo acts on mounting system  126 ′. The length of system  100 ′ of  FIG. 1B  may also be somewhat less than the length of system  100  of  FIG. 1A , and a front fulcrum or pivot point of the cantilevered structure is supported an underlying portion of the vehicle, rather than from above by a welded or bolted attachment. System  100  thus has some structural or strength advantages. Cargo cage  124  is also higher in system  100 ′, which provides more ground clearance during driving of vehicle  110 . However, the added height may make loading from the ground into cargo cage  124  more difficult with system  100 ′. Openings  128  used in system  100 ′ may also be less desirable cosmetically and may present weather proofing concerns. 
         [0023]      FIGS. 1C and 1D  respectively show systems  100  and  100 ′ in configurations where support beams  122  are retracted. In  FIG. 1C , cargo cage  124  has been removed, and support beams  122  have been retracted so that the end of support beams  122  do not extend beyond the rear bumper of vehicle  110 . In  FIG. 1D , a floor  125  of cargo cage  124  is attached to support beams. Generally, floor  125  and cargo cage  124  are removed and folded into a compact configuration for storage in the trunk of vehicle  110 . Alternatively, when wheel-less cargo carrier  120  is not in use, floor  125  when folded up can be stowed on support beams  122  as shown in  FIG. 1D . In one such embodiment, folding floor  125  of  FIG. 1D  may be permanently attached to support beams  122  and folds up as support beams are retracted. However, floor  125  may alternatively be removed, unfolded, and reattached when support beams  122  are extended, and removed, folded, and reattached to support beams  122  when support beams  122  are retracted. A cover (not shown) can fit over support beams  122  with or without folding floor  124  to improve appearance or weather proofing. 
         [0024]    An automotive system  100 ″ as shown in  FIGS. 1E and 1F  can include beams  122  as part of a drawer system having a drawer front  112 .  FIG. 1E  shows system  100 ″ when support beams  122  are extended to open the drawer system. A floor and cargo cage or basket can then be placed on beams for carrying cargo as described above with reference to  FIGS. 1A and 1B . The drawer system can be closed as shown in  FIG. 1F  so that support beams  122  are retracted and hidden. Drawer front  112  can have a shape and color matching the rest of the body of vehicle  110 , so that cargo carrier  120  is unobtrusive when not in use. 
         [0025]    Support beams  122  are telescoping beams and are extended in  FIGS. 1A ,  1 B, and  1 E and retracted in  FIGS. 1C ,  1 D, and  1 F. A power system (not shown) may be used to retract and/or extend support beams  122 . For example, an electric motor and gear system or a hydraulic piston system can extend or retract support beams  122 . However, for simplicity of construction and reduced cost, a manual system in which a person pulls on support beams  122  to extend beams  122  to the position of  FIG. 1A ,  1 B, or  1 E or pushes on support beams  122  to retract support beams  122  to the position of  FIG. 1C ,  1 D, or  1 F may be preferred. 
         [0026]      FIG. 2  shows a perspective view of a support beam  122  in accordance with an exemplary embodiment of the invention. In the illustrated embodiment, support beam  122  includes a rail holder  210 , a middle sliding rail  220 , and a inner sliding rail  230 . Alternative embodiments of a telescoping beam may include additional rails.  FIGS. 3A ,  3 B, and  3 C respectively show views of rail holder  210 , middle sliding rail  220 , and inner sliding rail  230  as separate components before assembly in support beam  122  of  FIG. 2  and are described in conjunction with  FIG. 2 . Each of rails  210 ,  220 , and  230  are preferably made of a strong light weight material such as an aluminum alloy and may be machined, forged, or assembled to provide their desired shapes. To assemble support beam  122 , inner sliding rail  230  can be inserted into middle sliding rail  220 , and the assembly including rails  230  and  220  can be inserted into rail holder  210 . 
         [0027]    Rail holder  210  is generally box shaped and in an exemplary embodiment is about 60 to 65 cm long, about 7 to 8 cm high, and about  7  to  8  cm wide. The top of rail holder  210  has openings  212  and  214 , and an opening  216  is in an end wall of rail holder  210 . Openings  214  and  216  respectively leave lips  215  and  217  that contact and guide middle sliding rail  220  as described further below. In use, the mounting system for support beam  122  generally fixes rail holder  210  in place relative to the vehicle. For example, rail holder  210  can be fit into and bolted to a section of square steel tubing that is anchored to the frame of a vehicle. 
         [0028]    Middle rail  220  includes a box shaped section  223  having top openings  222  and  224  and an end opening  226  similar to those found on rail holder  210 . Middle rail  220  also includes a guide section  229  having protrusions  228  that make guide section  229  wider than box section  223 . For example, middle rail  220  may be about 45 to 50 cm long, about 6 cm high, and about 4.8 cm wide, except where protrusions  228  make guide section  229  about 6.4 cm. Openings  212  and  214  in rail holder  220  are sized so that guide section  229  can be inserted into rail holder  210  through opening  212  while box section  223  is inserted through opening  214 . After middle rail  220  is inserted in rail holder  210 , sliding middle rail  220  causes protrusions  228  to fit under top lip  215  in rail holder  210 , preventing upward force or rotational torque from lifting guide section  229  from rail holder  210 . A cover (not shown) can be secured over opening  212  after insertion of middle rail  220  to prevent removal of middle rail  220  from rail holder  210 . Middle rail  220  when in rail holder  210  can slide forward and extend further from rail holder  210  until protrusions  228  reach and are stopped by front lip  217  of rail holder  210 . The height of middle rail  220  and the thickness of the bottom of rail holder  210  are chosen so that the top of middle rail  220  when inserted in rail holder  210  is substantially coplanar with the top of rail holder  210 . 
         [0029]    Inner rail  230  is substantially box shaped except for protrusions  238  and post  232 . In the exemplary embodiment, inner rail  230  may be about 45 to 50 cm long, about 4 cm high, and about 2.5 cm wide, except where protrusions  238  make inner rail  230  about 3.8 cm wide. Openings  222  and  224  in middle rail  220  are sized so that protrusion  238  can be inserted into middle rail  220  through opening  222  while the remainder of inner rail  230  fits through openings  224  and  226 . After inner rail  230  is inserted in middle rail  220 , sliding inner rail  230  causes protrusions  238  to fit under a top lip  225  in middle rail  220 , preventing upward force or rotational torque from lifting protrusions  238  from middle rail  220 . Inner rail  230  when inserted in middle rail  220  is able to slide forward and extend further from middle rail  220  until protrusions  238  reach and are stopped by front lips  227  of middle rail  220 . The height of inner rail  230  and the thickness of the bottom of middle rail  220  are chosen so that the top of inner rail  230  when inserted in middle rail  220  is substantially coplanar with the tops of middle rail  220  and rail holder  210 . 
         [0030]    A post or bolt  232 , which extends upward from inner rail  230 , acts as a handle to help a user to push or pull on inner rail  230  when extending or retracting support beam  122 . Post  232  can also be used for rapid and secure attachment of other portions (e.g., a cross beam or fence and gate structures) of a wheel-less cargo carrier including support beam  122 . 
         [0031]      FIG. 4  shows a semi-transparent view of an embodiment of support beam  122 . As described above, rails  230 ,  220 , and  210  in support beam  122  are nested so that the tops of rails  230 ,  220 , and  210  are coplanar, which provides a flat and level surface for supporting the floor of a wheel-less cargo carrier. Beam  122  also extends and retracts in telescope fashion through the sliding of inner rail  230  relative to middle rail  220  and the sliding of middle rail  220  relative to rail holder  210 . Protrusions  238  from inner rail  230  engage notches in the side walls of middle rail  220  to guide movement of inner rail  230 , and protrusions  228  from middle rail  230  engage notches in the side walls of rail holder  210  to guide movement of middle rail  220 . As illustrated in  FIG. 4 , rollers  420  and  430  can be provided where protrusions  228  and  238  respectively contact rail holder  210  and middle rail  220 . 
         [0032]      FIG. 5A  shows a support base  500  for a wheel-less cargo carrier in accordance with an embodiment of the invention. Base  500  includes two telescoping support beams  122 , a back cross beam  510 , and a front cross beam  520 . As illustrated, holes in cross beam  520  may fit over posts  232  in inner rails  230 . Base  500  also includes one or more folding beams  530 , which are pivotally attached to cross beams  510  and  520  and hinged to permit beams  530  to fold while maintaining a top surface of beams  530  in the plane of the top surfaces of telescoping beams  122 . In an alternative embodiment, folding beams  530  could be replaced with one or more additional telescoping beams  122 , but if base  500  is mounted under a vehicle body, center telescoping rails may interfere with access to a spare tire or use of a cargo carrier hitch on the vehicle. However, for mounting above the floor or under body of the vehicle, replacing folding beams  530  with a pair of telescoping support beams may be preferred. 
         [0033]    The use of multiple telescoping beams  122  (e.g., two in  FIG. 5A  or four in an embodiment that replaces folding beams  530  with two telescoping beams) increases the amount of weight that base  500  can support when compared to a system suspended from a trailer hitch. Multiple beams  122  also provide stability against torques about the axis of a trailer hitch, which is important when cargo is not perfectly balanced about the hitch axis. Accordingly, embodiments of base  500  can achieve carrying capacities of up to hundreds of pounds without the need for expensive materials. 
         [0034]      FIG. 5A  shows base  500  in a fully extended configuration. The fully extended configuration provides the most floor space for the wheel-less cargo carrier but also provides the greatest moment arm on the mountings of beams  122  to a vehicle and the longest vehicle length (including cargo carrier). The long moment arm may decrease the maximum weight load of the wheel-less cargo carrier and may make the vehicle less maneuverable. 
         [0035]    In accordance with an aspect of the invention, the wheel-less cargo carrier can be used in fully extended configuration of  FIG. 5A  or in a partially extended (e.g., half length) configuration.  FIG. 5B  shows a partially extended configuration for platform  500 . This configuration differs from the configuration of  FIG. 5A  in that telescoping beams  122  are less extended and folding beams  530  are more folded. This provides less cargo floor area but less moment arm, so that heavy cargo might be more safely transported. 
         [0036]      FIG. 5C  shows a fully retracted configuration of base  500 . Platform  500  may be retracted as shown in  FIG. 5C  when the wheel-less cargo carrier is not in use. However, to provide a more compact not-in-use configuration, cross-beams  510  and  520  and folding beams  510  may be removed and stored externally or in the vehicle, so that beams  122  can be fully retracted. 
         [0037]    In accordance with a further aspect of the invention, a floor for a wheel-less cargo carrier may include hinged panels.  FIG. 6 , for example, illustrates a floor  125  containing multiple panels  610 . Each panel  610  may be made of a suitably strong material such as wood or metal and has a hinge structure along its edge with each adjacent panel  610 . The hinge structure may run the entire length of the edge as shown in  FIG. 6  or may alternatively include multiple separated hinges. The hinges permit panels  610  to fold accordion style to provide a compact configuration when floor  125  is not in use on a wheel-less cargo carrier. Additionally, one or more panels  610  may be removed from floor  125 , for example, by removal of a hinge pin or similar structure. Removal or addition of panels  610  changes the size of floor  125 , which may be needed, for example, when the wheel-less cargo carrier  500  is used in the fully extended configuration of  FIG. 5A  or the partly extended configuration of  FIG. 5B . 
         [0038]    A cargo cage or basket can include a similar hinged structure that can form a square or rectangle with hinges at  90  degree angles or be folded flat for storage. 
         [0039]    Although the invention has been described with reference to particular embodiments, the description is only an example of the invention&#39;s application and should not be taken as a limitation. Various adaptations and combinations of features of the embodiments disclosed are within the scope of the invention as defined by the following claims.