Level lift trailer with detachable cargo bed

An open center trailer with spring suspended axles 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.

BACKGROUND

1. Technical Field

The present invention pertains generally to the field of hauling cargo on highways with motor vehicles and more specifically to cargo carried with trailers.

2. Description of Related Art

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.

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.

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.

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

The present invention is directed to a heavy level lift trailer system in which its cargo is always level with the ground, whether it is being raised into transport position or being lowered to the ground. The same design is applicable to light systems as well.

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 unloaded while sitting on the ground and detaching from the trailer. In other words, a single trailer that can move a variety of cargo beds whether loaded or unloaded. This system feature uniquely suits 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.

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.

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.

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.

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.

DETAILED DESCRIPTION

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.

Referring to the drawings,FIG. 1is a perspective view of a trailer system1of the preferred embodiment. The trailer system1has a trailer assembly2and a cargo bed assembly3which is sitting on the ground4and partially detached from the trailer assembly2.

In the embodiment ofFIG. 1, the trailer assembly2has a tongue23which is attached to a head structure24. The head structure24is further attached to four side structure beams17,18,21and22where side structure beams17and21attached to one end of the head structure24and side structure beams18and22attached to the other end of the head structure24. Side structure beams17and21separate from side structure beams18and22by an open space16. Two rear lifting rollers34are disposed to the opposite inner surface of the side structure beams21and22. Two front lifting rollers35are disposed to the opposite inner surface of the side structure beams21and22. The front lifting rollers35are mounted at a level lower than the rear lifting rollers34.

In the embodiment ofFIG. 1, the cargo bed assembly3has a bed5, two opposite side walls6, a head end8, and a ramp7. Two inclined channel tracks12are angled substantially at 45 degrees toward the ground4and are disposed to the outside surface of the side walls6near the head end8. Two additional inclined channel tracks13angled substantially parallel to the inclined channel tracks12are disposed to the outside surface of the side walls6near the ramp7of the cargo bed assembly3. The inclined channel tracks12are sized to receive the front lifting rollers35while the inclined channel tracks13are sized to receive the rear lifting rollers34. Two horizontal channel extensions14are disposed to the outside surface of the side walls6and horizontally extending from the head end8to the upper ends of the inclined channel tracks12. Additionally, two horizontal channel extensions15are disposed to the outside surface of the side walls6and horizontally extending from the head end8to the upper ends of the inclined channel tracks13. The horizontal channel extensions14are used to receive and guide the front lifting rollers35while the horizontal channel extensions15are used to receive and guide the rear lifting rollers34.

FIG. 2ashows a side view of one embodiment of the cargo bed assembly3ofFIG. 1. The horizontal channel extensions14and15are disposed to the side walls6and extending from the head end8and to the upper ends of the inclined channel tracks12,13. A cargo bed fitting38is attached to the central lower portion of the outside surface of the head end8of the cargo bed assembly3to facilitate the cargo bed assembly3to be engaged with the trailer assembly2.

FIG. 2bis a side view of another embodiment of the cargo bed assembly3ofFIG. 1. The horizontal channel extensions14and15are disposed to the side walls6and extending from the head end8and to the upper ends of the inclined channel tracks12,13. At one end of the horizontal channel extension15is an enlarged opening54which is able to facilitate the receiving of the trailer lifting rollers34. Similarly, at one end of the horizontal channel extension14is an enlarged opening52which is able to facilitate the receiving of the trailer lifting rollers35. A pintle ring58is attached to the central lower portion of the outside surface of the head end8of the cargo bed assembly3to facilitate the cargo bed assembly3to be engaged with the trailer assembly2.

FIG. 3is a front end view of one embodiment of the cargo bed assembly3ofFIG. 2a.FIG. 3shows the head end8of the cargo bed assembly3and the horizontal channel extensions14,15on both side walls6of the cargo bed assembly3. The cargo bed fitting38is located at the central lower portion on the outside surface of the head end8of the cargo bed assembly3.

FIG. 4shows a plan view of the lift trailer ofFIG. 1. In the embodiment ofFIG. 4, the tongue23is attached to the head structure24which separates side structure beams17,21and18,22by the open space16. The rear lifting rollers34are disposed to the opposite inner surface of the side structure beams21and22. The front lifting rollers35are disposed to the opposite inner surface of the side structure beams21and22. A package engine, a hydraulic pump, a reservoir and a valve are mounted at a space36.

FIG. 5is a back end view of the trailer assembly2ofFIG. 1. The front lifting rollers35are mounted at a level lower than the rear lifting rollers34, and all lifting rollers34,35are extended into the open space16.

FIG. 6is a sectional view taken along line10-10ofFIG. 4.FIG. 7is a sectional view taken along line20-20ofFIG. 4. Referring to bothFIG. 6andFIG. 7, the quarter axles25, the leaf springs32, and their brackets33fit under the side structure beams17,21to maintain the open space16. One end of the quarter axles25is fitted with a pivot tube26which is jointed to the side structure beams17,21to preserve alignment of the tires28which is mounted on a break spindle27that attached to the other end of the quarter axles25.

FIG. 8is a partial plan view of the lift trailer2ofFIG. 1with the cargo bed3lowered to ground level.FIG. 8also shows the location of section line30-30through the lifting rollers34,35and the inclined channel tracks12,13.

FIG. 9ais an elevational sectional view of one embodiment of the lift trailer assembly2ofFIG. 1taken along line30-30ofFIG. 8with the cargo bed assembly3lowered to the ground4. A hydraulic cylinder37is extended to a full stroke position against the tongue23of the lift trailer assembly2and the cargo bed fitting38of the cargo bed assembly3.

FIG. 9bis an elevational sectional view of another embodiment of the lift trailer assembly2ofFIG. 1taken along line30-30ofFIG. 8with a cargo bed assembly3lowered to the ground4. A hydraulic cylinder37is extended to a half stroke position against the tongue23of the trailer assembly2. The hydraulic cylinder37has a cylinder shaft64that is able to stroke the hydraulic cylinder37. A hook56is located at the open end of the cylinder shaft64. A pintle ring58is attached to the central lower portion of the outside surface of the head end8of the cargo bed assembly3. In one embodiment, the pintle ring58is bolted to the head end8. Therefore, the hydraulic cylinder37and the cargo bed assembly3can be engaged by placing the hook56into the eye of the pintle ring58for the cargo bed assembly3to be raised up from the ground position to the transport position or laid down from the transport position to the ground position. The cargo bed assembly3can be quickly disengaged from the lift trailer assembly2by removing the hook56of the cylinder shaft64away from the pintle ring58of the cargo bed assembly3when the cargo bed is sitting on the ground position. A hydraulic cylinder mount bracket62is mounted in a position to hold the hydraulic cylinder37on an angle to facilitate the hydraulic cylinder hook56to be engaged with the pintle ring58.

FIG. 10is an enlarged sectional view taken along line40-40ofFIG. 9aorFIG. 9b. In the embodiment ofFIG. 10, the rear lifting roller34is attached to the side structure beams17,21and engaged in the horizontal channel extension15mounted on the side wall6.

FIG. 11is an enlarged portion ofFIG. 9aviewed from the same vantage point. InFIG. 11, an open lock assembly41is mounted on the inclined channel track12with a spring loaded lock pin42which is latched open on a hook43.

FIG. 12ais an elevational sectional view of the trailer assembly2ofFIG. 1with the cargo bed assembly3ofFIG. 2araised to a transport position. The hydraulic cylinder37is in a retracted position, attaching to the cargo bed assembly3at the bed fitting38and to the tongue23of the trailer assembly2.

FIG. 12bis an elevational sectional view of the trailer assembly2ofFIG. 1with the cargo bed assembly3ofFIG. 2braised to a transport position. The hydraulic cylinder37is in fully retracted position and the hook56of the cylinder shaft64is engaged with the pintle ring58of the cargo bed assembly3.

FIG. 13is an enlarged portion ofFIG. 12aviewed from the same vantage point. As shown inFIG. 12aorFIG. 12b, the cargo bed assembly3is raised to a transport position. InFIG. 13, the front lifting roller35in rolled into the inclined channel track12where the spring loaded lock pin42of the open lock assembly41is latched through the channel track12, thus holding the cargo bed assembly3in the transport position without depending on the hydraulic pressure from the cylinder37.

Alternate designs for cargo bed assembly3are shown inFIGS. 14a-14f.FIG. 14ais a perspective view of an alternate cargo bed assembly3with portable highway traffic light.FIG. 14bis a perspective view of an alternate cargo bed with enclosed cargo box with multiple doors and cabinets.FIG. 14cis a perspective view of an alternate cargo bed with ground level loading horse compartment.FIG. 14dis a perspective view of an alternate dumping cargo bed.FIG. 14eis a perspective view of an alternate cargo bed with traffic speed sign.FIG. 14fis 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.

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.