Abstract:
An open center trailer with spring suspended axels which straddle a detached cargo bed, which was loaded on the ground, said trailer level lifts the cargo bed by pulling said cargo bed up its channel ramps to an elevated transport height, and consequently level lowers and detaches from this load bed at another location. This load may be a cargo utility platform, or an enclosed cargo box, or a horse traveling compartment, or a dump bed, or a highway light, or a traffic speed sign.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of co-pending U.S. application Ser. No. 12/001,673, filed Dec. 11, 2007, which was a continuation-in-part of U.S. application Ser. No. 10/817,368 filed Apr. 5, 2004 (now abandoned). This application claims the benefit of U.S. application Ser. No. 12/001,673, filed Dec. 11, 2007 and U.S. application Ser. No. 10/817,368 filed Apr. 5, 2004, the entirety of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention pertains generally to the field of hauling cargo on highways with motor vehicles and more specifically to cargo carried with trailers. 
         [0004]    2. Description of Related Art 
         [0005]    A loaded cargo is usually carried over a hauling cargo bed which is mounted on a truck chassis frame. In order to achieve this, it is required to lift up the cargo onto the hauling bed. Many designs have sought to ease this task. U.S. Pat. No. 2,485,300 issued to Lisota uses a tilting and moving bed to load or unload a truck. Many refinements of this method are used to lift up large cargo containers on truck chassis. LaMora in U.S. Pat. No. 5,460,473 shows a system using a trailer to haul two containers in line. Alternately, U.S. Pat. No. 6,099,232 to Dixon shows a smaller cargo bed loaded into a pick up truck. Although these methods are widely used today, they are not practical for unpacked cargoes, nor can they be used to load or unload live animals. 
         [0006]    U.S. Pat. No. 2,230,014 issued to Haven describes a lifting/lowering trailer using a system of cams and links. Verschage in U.S. Pat. No. 4,372,572 uses cams, links and hydraulic cylinders to lift heavy loads, such as fork lifts. U.S. Pat. No. 5,630,693 issued to Sobina shows a design of a level lift trailer bed which is kept in alignment by inner sliding telescoping guides as it is lifted by hydraulic cylinders at each corner of the chassis. In each of these devices, the cargo or load carrying member is a permanent integral part of the trailer. 
         [0007]    Adding versatility to his tilting frame trailer, Pihlstrom in U.S. Pat. No. 4,930,799 is able to interchange the cargo carrier. But, this system can not lift a loaded cargo carrier. 
         [0008]    Therefore, there is a strong desire for a simple, reliable and heavy capacity level lifting trailer system capable of detaching from its cargo bed, or from an interchangeable bed, in some other configurations. 
       SUMMARY 
       [0009]    The present invention is directed to a heavy level lift trailer system in which its cargo is always level with the ground, weather it is being raised into transport position or being lowered to the ground. The same design is applicable to light systems as well. 
         [0010]    A further novel feature of the invention is the ability to release a cargo bed from the trailer. Therefore the cargo bed can be loaded and unload while sitting on the ground and detaching from the trailer. In other words, a single trailer that can move a variety of cargo beds weather loaded or unloaded. This system feature uniquely suites the delivery process of the manufacturing and the construction industries. The cargo beds are not necessarily to be the same, one delivery might be a load of wood, and the next could be a lockable multi door tool crib attached to saw table and stock rack. 
         [0011]    Accordingly, it is another object of the present invention to provide a safe and easy transportation of live cargoes such as horses. A ground level loading and unloading of horses removes the danger and risk of injury to these animals. 
         [0012]    It is yet a further object of the present invention to provide an alternate design which may be incorporated into specialized systems for use in areas where very high theft potential prevails. The novel feature of raising up and lowering down a trailer bed allows for an inexpensive single axle custom cargo bed to be used in areas where the equipment must be left unattended for an extended period of time. Thus, the tires and wheels of the trailer are is never exposed. 
         [0013]    To these ends, the level lifting trailer with the option of multiple detachable cargo beds in the present invention, compromises a safe and economical cargo-transfer and delivery system. 
         [0014]    These and other objects, features, aspects, and advantages of the present invention will become better understood with reference to the following description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a perspective view of one embodiment of a lift trailer with a cargo bed lowered and partially removed. 
           [0016]      FIG. 2   a  is a side view of one embodiment of the cargo bed of  FIG. 1 . 
           [0017]      FIG. 2   b  is a side view of another embodiment of the cargo bed of  FIG. 1 . 
           [0018]      FIG. 3  is a front end view of one embodiment of the cargo bed of  FIG. 2   a.    
           [0019]      FIG. 4  is a plan view of the lift trailer of  FIG. 1 . 
           [0020]      FIG. 5  is a back end view of the lift trailer of  FIG. 1 . 
           [0021]      FIG. 6  is a sectional view taken along line  10 - 10  of  FIG. 4 . 
           [0022]      FIG. 7  is a sectional view taken along line  20 - 20  of  FIG. 4 . 
           [0023]      FIG. 8  is a partial plan view of the lift trailer of  FIG. 1  with the cargo bed lowered to ground level. 
           [0024]      FIG. 9   a  is an elevational sectional view of one embodiment of the lift trailer of  FIG. 1  taken along line  30 - 30  of  FIG. 8  with a cargo bed lowered to ground level. 
           [0025]      FIG. 9   b  is an elevational sectional view of another embodiment of the lift trailer of  FIG. 1  taken along line  30 - 30  of  FIG. 8  with a cargo bed lowered to ground level. 
           [0026]      FIG. 10  is an enlarged sectional view taken along line  40 - 40  of  FIG. 9   a  or  FIG. 9   b.    
           [0027]      FIG. 11  is an enlarged sectional view taken along line  50 - 50  of  FIG. 9   a.    
           [0028]      FIG. 12   a  is an elevational sectional view of one embodiment of the lift trailer of  FIG. 1  with the cargo bed of  FIG. 2   a  raised to a transport position. 
           [0029]      FIG. 12   b  is an elevational sectional view of another embodiment of the lift trailer of  FIG. 1  with the cargo bed of  FIG. 2   b  raised to a transport position. 
           [0030]      FIG. 13  is an enlarged sectional view taken along line  60 - 60  of  FIG. 12   a.    
           [0031]      FIG. 14   a  is a perspective view of an alternate cargo bed with portable highway traffic light. 
           [0032]      FIG. 14   b  is a perspective view of an alternate cargo bed with enclosed cargo box. 
           [0033]      FIG. 14   c  is a perspective view of an alternate cargo bed with ground level loading horse compartment. 
           [0034]      FIG. 14   d  is a perspective view of an alternate dumping cargo bed. 
           [0035]      FIG. 14   e  is a perspective view of an alternate cargo bed with traffic speed sign. 
           [0036]      FIG. 14   f  is a perspective view of an alternate cargo bed with open cargo platform with castered wheels. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    Description will be hereinafter made of one embodiment of a level lift trailer with detachable cargo bed according to the present invention with reference to the drawings. Additionally, in the following descriptions of the drawings, the same or similar portions are assigned with the same or similar reference symbols. It should be noted that each drawing is a schematic diagram, and may represent different dimensional ratios and the like from those of the actual vehicle. Hence, specific dimensions and the like should be determined in consideration of the following descriptions. Furthermore, as a matter of course, different drawings include elements which have different dimensional relations and ratios. 
         [0038]    Referring to the drawings,  FIG. 1  is a perspective view of a trailer system  1  of the preferred embodiment. The trailer system  1  has a trailer assembly  2  and a cargo bed assembly  3  which is sitting on the ground  4  and partially detached from the trailer assembly  2 . 
         [0039]    In the embodiment of  FIG. 1 , the trailer assembly  2  has a tongue  23  which is attached to a head structure  24 . The head structure  24  is further attached to four side structure beams  17 ,  18 ,  21  and  22  where side structure beams  17  and  21  attached to one end of the head structure  24  and side structure beams  18  and  22  attached to the other end of the head structure  24 . Side structure beams  17  and  21  separate from side structure beams  18  and  22  by an open space  16 . Two rear lifting rollers  34  are disposed to the opposite inner surface of the side structure beams  21  and  22 . Two front lifting rollers  35  are disposed to the opposite inner surface of the side structure beams  21  and  22 . The front lifting rollers  35  are mounted at a level lower than the rear lifting rollers  34 . 
         [0040]    In the embodiment of  FIG. 1 , the cargo bed assembly  3  has a bed  5 , two opposite side walls  6 , a head end  8 , and a ramp  7 . Two inclined channel tracks  12  are angled substantially at  45  degrees toward the ground  4  and are disposed to the outside surface of the side walls  6  near the head end  8 . Two additional inclined channel tracks  13  angled substantially parallel to the inclined channel tracks  12  are disposed to the outside surface of the side walls  6  near the ramp  7  of the cargo bed assembly  3 . The inclined channel tracks  12  are sized to receive the front lifting rollers  35  while the inclined channel tracks  13  are sized to receive the rear lifting rollers  34 . Two horizontal channel extensions  14  are disposed to the outside surface of the side walls  6  and horizontally extending from the head end  8  to the upper ends of the inclined channel tracks  12 . Additionally, two horizontal channel extensions  15  are disposed to the outside surface of the side walls  6  and horizontally extending from the head end  8  to the upper ends of the inclined channel tracks  13 . The horizontal channel extensions  14  are used to receive and guide the front lifting rollers  35  while the horizontal channel extensions  15  are used to receive and guide the rear lifting rollers  34 . 
         [0041]      FIG. 2   a  shows a side view of one embodiment of the cargo bed assembly  3  of  FIG. 1 . The horizontal channel extensions  14  and  15  are disposed to the side walls  6  and extending from the head end  8  and to the upper ends of the inclined channel tracks  12 ,  13 . A cargo bed fitting  38  is attached to the central lower portion of the outside surface of the head end  8  of the cargo bed assembly  3  to facilitate the cargo bed assembly  3  to be engaged with the trailer assembly  2 . 
         [0042]      FIG. 2   b  is a side view of another embodiment of the cargo bed assembly  3  of  FIG. 1 . The horizontal channel extensions  14  and  15  are disposed to the side walls  6  and extending from the head end  8  and to the upper ends of the inclined channel tracks  12 ,  13 . At one end of the horizontal channel extension  15  is an enlarged opening  54  which is able to facilitate the receiving of the trailer lifting rollers  34 . Similarly, at one end of the horizontal channel extension  14  is an enlarged opening  52  which is able to facilitate the receiving of the trailer lifting rollers  35 . A pintle ring  58  is attached to the central lower portion of the outside surface of the head end  8  of the cargo bed assembly  3  to facilitate the cargo bed assembly  3  to be engaged with the trailer assembly  2 . 
         [0043]      FIG. 3  is a front end view of one embodiment of the cargo bed assembly  3  of  FIG. 2   a .  FIG. 3  shows the head end  8  of the cargo bed assembly  3  and the horizontal channel extensions  14 ,  15  on both side walls  6  of the cargo bed assembly  3 . The cargo bed fitting  38  is located at the central lower portion on the outside surface of the head end  8  of the cargo bed assembly  3 . 
         [0044]      FIG. 4  shows a plan view of the lift trailer of  FIG. 1 . In the embodiment of  FIG. 4 , the tongue  23  is attached to the head structure  24  which separates side structure beams  17 ,  21  and  18 ,  22  by the open space  16 . The rear lifting rollers  34  are disposed to the opposite inner surface of the side structure beams  21  and  22 . The front lifting rollers  35  are disposed to the opposite inner surface of the side structure beams  21  and  22 . A package engine, a hydraulic pump, a reservoir and a valve are mounted at a space  36 . 
         [0045]      FIG. 5  is a back end view of the trailer assembly  2  of  FIG. 1 . The front lifting rollers  35  are mounted at a level lower than the rear lifting rollers  34 , and all lifting rollers  34 ,  35  are extended into the open space  16 . 
         [0046]      FIG. 6  is a sectional view taken along line  10 - 10  of  FIG. 4 .  FIG. 7  is a sectional view taken along line  20 - 20  of  FIG. 4 . Referring to both  FIG. 6  and  FIG. 7 , the quarter axles  25 , the leaf springs  32 , and their brackets  33  fit under the side structure beams  17 ,  21  to maintain the open space  16 . One end of the quarter axles  25  is fitted with a pivot tube  26  which is jointed to the side structure beams  17 ,  21  to preserve alignment of the tires  28  which is mounted on a break spindle  27  that attached to the other end of the quarter axles  25 . 
         [0047]      FIG. 8  is a partial plan view of the lift trailer  2  of  FIG. 1  with the cargo bed  3  lowered to ground level.  FIG. 8  also shows the location of section line  30 - 30  through the lifting rollers  34 ,  35  and the inclined channel tracks  12 ,  13 . 
         [0048]      FIG. 9   a  is an elevational sectional view of one embodiment of the lift trailer assembly  2  of  FIG. 1  taken along line  30 - 30  of  FIG. 8  with the cargo bed assembly  3  lowered to the ground  4 . A hydraulic cylinder  37  is extended to a full stroke position against the tongue  23  of the lift trailer assembly  2  and the cargo bed fitting  38  of the cargo bed assembly  3 . 
         [0049]      FIG. 9   b  is an elevational sectional view of another embodiment of the lift trailer assembly  2  of  FIG. 1  taken along line  30 - 30  of  FIG. 8  with a cargo bed assembly  3  lowered to the ground  4 . A hydraulic cylinder  37  is extended to a half stroke position against the tongue  23  of the trailer assembly  2 . The hydraulic cylinder  37  has a cylinder shaft  64  that is able to stroke the hydraulic cylinder  37 . A hook  56  is located at the open end of the cylinder shaft  64 . A pintle ring  58  is attached to the central lower portion of the outside surface of the head end  8  of the cargo bed assembly  3 . In one embodiment, the pintle ring  58  is bolted to the head end  8 . Therefore, the hydraulic cylinder  37  and the cargo bed assembly  3  can be engaged by placing the hook  56  into the eye of the pintle ring  58  for the cargo bed assembly  3  to be raised up fiorn the ground position to the transport position or laid down from the transport position to the ground position. The cargo bed assembly  3  can be quickly disengaged from the lift trailer assembly  2  by removing the hook  56  of the cylinder shaft  64  away from the pintle ring  58  of the cargo bed assembly  3  when the cargo bed is sitting on the ground position. A hydraulic cylinder mount bracket  62  is mounted in a position to hold the hydraulic cylinder  37  on an angle to facilitate the hydraulic cylinder hook  56  to be engaged with the pintle ring  58 . 
         [0050]      FIG. 10  is an enlarged sectional view taken along line  40 - 40  of  FIG. 9   a  or  FIG. 9   b . In the embodiment of  FIG. 10 , the rear lifting roller  34  is attached to the side structure beans  17 ,  21  and engaged in the horizontal channel extension  15  mounted on the side wall  6 . 
         [0051]      FIG. 11  is an enlarged sectional view taken along line  50 - 50  of  FIG. 9   a . In  FIG. 11 , an open lock assembly  41  is mounted on the inclined channel track  12  with a spring loaded lock pin  42  which is latched open on a hook  43 . 
         [0052]      FIG. 12   a  is an elevational sectional view of the trailer assembly  2  of  FIG. 1  with the cargo bed assembly  3  of  FIG. 2   a  raised to a transport position. The hydraulic cylinder  37  is in a retracted position, attaching to the cargo bed assembly  3  at the bed fitting  38  and to the tongue  23  of the trailer assembly  2 . 
         [0053]      FIG. 12   b  is an elevational sectional view of the trailer assembly  2  of  FIG. 1  with the cargo bed assembly  3  of  FIG. 2   b  raised to a transport position. The hydraulic cylinder  37  is in fully retracted position and the hook  56  of the cylinder shaft  64  is engaged with the pintle ring  58  of the cargo bed assembly  3 . 
         [0054]      FIG. 13  is an enlarged sectional view taken along line  60 - 60  of  FIG. 12   a . As shown in  FIG. 12   a  or  FIG. 12   b , the cargo bed assembly  3  is raised to a transport position. In  FIG. 13 , the front lifting roller  35  in rolled into the inclined channel track  12  where the spring loaded lock pin  42  of the open lock assembly  41  is latched through the channel track  12 , thus holding the cargo bed assembly  3  in the transport position without depending on the hydraulic pressure from the cylinder  37 . 
         [0055]    Alternate designs for cargo bed assembly  3  are shown in  FIGS. 14   a - 14   f .  FIG. 14   a  is a perspective view of an alternate cargo bed assembly  3  with portable highway traffic light.  FIG. 14   b  is a perspective view of an alternate cargo bed with enclosed cargo box with multiple doors and cabinets.  FIG. 14   c  is a perspective view of an alternate cargo bed with ground level loading horse compartment.  FIG. 14   d  is a perspective view of an alternate dumping cargo bed.  FIG. 14   e  is a perspective view of an alternate cargo bed with traffic speed sign.  FIG. 14   f  is a perspective view of an alternate cargo bed with open cargo platform with tie down loops and castered non-highway wheels, for ease of movement around the shop. 
         [0056]    While various embodiments of a level lift trailer with detachable cargo bed and its respective components have been presented in the foregoing disclosure, numerous modifications, alterations, alternate embodiments, and alternate materials may be contemplated by those skilled in the art and may be utilized in accomplishing the various aspects of the present invention. Thus, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the invention as claimed below.