Level lift cargo trailer

Abstract

A level lift trailer comprising a chassis and a cargo tray slidably coupled to the chassis via slide track bearings to move between raised and lowered positions. The chassis includes side frames, each defining a raised wheel arch frame. Suspension assemblies interface with the wheel arch frames, each suspension assembly having a swing arm pivotally coupled at a proximal end to a respective side frame, compressing a compression member connected between a distal end of the swing arm and the raised wheel arch frame, and engaging a trailer wheel between the proximal and distal ends. Each side frame supports a pair of slide track bearings fore and aft of its respective wheel arch frame, with each slide track bearing comprising an angled track channel affixed to the cargo tray and a bearing engaged within the channel and affixed to the side frame, facilitating smooth and stable movement of the cargo tray.

Description

Level Lift Cargo TrailerField of the Invention

[0001] The present invention relates to cargo trailers, specifically a level lift cargo trailer configured with a suspension arrangement designed to enhance stability and enable efficient loading, unloading, and transportation of goods across diverse terrains and operational conditions.Background of the Invention

[0002] Level lift trailers are commonly used for transporting cargo, offering the ability to adjust the position of the cargo tray to facilitate loading and unloading. These trailers are particularly valuable when dealing with heavy or bulky items that require the cargo tray to be lowered close to or onto the ground. However, conventional designs often face challenges in maintaining stability and ensuring smooth movement of the tray during transitions between raised and lowered positions.

[0003] A recurring problem with traditional level lift trailers is the difficulty in balancing load distribution. Instability during these transitions and during transportation can, in some cases, compromise safety. Furthermore, the suspension systems of many conventional level lift trailers are also prone to limitations, particularly in their ability to accommodate uneven terrain or absorb shocks effectively.

[0004] Overall, while level lift trailers provide significant utility in cargo transportation, the challenges associated with stability, adaptability, and durability highlight the need for improved designs that address these limitations.

[0005] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.Summary of the Disclosure

[0006] The described level lift trailer comprises a chassis and a cargo tray with slide track bearings slidably coupling the cargo tray to the chassis between raised and lowered positions. The chassis includes side frames, each defining a raised wheel arch frame, and suspension assemblies interfacing with the wheel arch frames. Eachsuspension assembly comprises a swing arm pivotally coupled at a proximal end to a respective side frame, compressing a compression member connected between a distal end of the swing arm and the raised wheel arch frame, and engaging a trailer wheel between the proximal and distal ends.

[0007] The arrangement of the slide track bearings, including an angled track channel affixed to the cargo tray and a bearing engaged within the channel and affixed to the side frame, facilitates smooth and stable movement of the cargo tray. The suspension assemblies support the trailer wheels in a manner unconstrained by the side frames, allowing the wheel hubs to travel into the voids defined by the wheel arch frames when compressed under load or during road undulations.

[0008] The sliding coupling of the cargo tray to the chassis through slide track bearings ensures smooth and stable movement between raised and lowered positions, facilitating effortless cargo handling and minimising mechanical wear. The chassis, with its raised wheel arch frames, provides a robust structural framework that supports the suspension assemblies and allows for efficient load handling. The suspension assemblies, incorporating swing arms pivotally coupled to the chassis and compressing a connected member, deliver superior shock absorption and stability, ensuring a smooth ride and protecting cargo from vibrations. The suspension assemblies also allow the trailer wheels to move freely without being constrained by the side frames, with the wheel hubs travelling into the voids defined by the raised wheel arch frames under load or during road undulations, improving adaptability and ride quality.

[0009] The dual slide track bearings provide additional support by maintaining the cargo tray level fore and aft of the wheel arch frames during raising and lowering, ensuring stable engagement centred around the wheel hubs during transportation. Additionally, the configuration of the swing arms to engage the trailer wheels between the proximal and distal ends optimises load distribution and enhances the trailer's overall performance and durability.

[0010] Preferably, the raised wheel arch frame defines fore and aft risers and a raised crossbar therebetween. Angle bracing may interface between the risers and the crossbar, improving structural rigidity and resistance to deformation under load.

[0011] The compression member is preferably connected to the raised crossbar, allowing sufficient space for full operation of the compression member and the swing arm may be pivotally coupled to one of the risers, enhancing the mechanical support and ensuring precise articulation of the suspension assembly.

[0012] In some embodiments, the swing arm is downwardly curved between the proximal and distal ends. This configuration allows the wheel hub to be positioned beneath the pivot point, enabling a compact design and greater suspension travel.

[0013] Preferably, the swing arm is located on the inside of its respective trailer wheel, which provides accessible exposure to the wheel hub for maintenance and reduces lateral space requirements.

[0014] The distal end of the swing arm may include a laterally projecting bar configured to reciprocate between the wheel and an adjacent riser, improving the integration of suspension components and the mechanical efficiency of load transfer.

[0015] In certain embodiments, the laterally projecting bar engages a plurality of compression members, such as a compression strut and a pneumatic airbag. This combination provides enhanced suspension versatility and adaptability to varying loads. The proximal end of the swing arm may include a laterally projecting pin configured to pivotally engage a collar connected to an adjacent riser.

[0016] The angled track channel is preferably a C-channel defining an outwardly facing open channel closed at its terminal ends, providing secure guidance for the cargo tray and minimising the risk of derailment at extreme ranges of movement.

[0017] The angled track channels may be angled forward such that the cargo tray descends rearwardly during movement to the lowered position and ascends forwardly during movement to the raised position.

[0018] Locking pins may be provided rearwardly on the side frames to engage aligned apertures in the cargo tray, securing it in the raised position and preventing unintended movement during transportation. Optionally, front locking tabs alignedwith corresponding apertures across a front edge of the cargo tray may be used to further secure the cargo tray in the raised position with a fastener, enhancing safety.

[0019] An electric winch may be included to raise and lower the cargo tray via a winch cable, simplifying operation and enabling powered movement of the cargo tray. The winch cable may feed over a pulley wheel, ensuring smooth and controlled movement of the cargo tray during raising and lowering. The electric winch may operate from a vehicle's electrical supply or a separate battery.

[0020] The cargo tray may include a tailgate hingedly coupled to the floor and movable between raised and lowered positions. The tailgate may be wedge-shaped to minimise the on-ramp edge, enabling smoother loading of heavy or wheeled cargo. Wedge-shaped bracing may support the tailgate, ensuring structural durability.

[0021] The suspension assemblies may be configured to allow the wheel hubs of the trailer wheels to travel into the voids defined by the raised wheel arch frames when compressed, improving suspension performance and load handling.

[0022] The swing arm may include a wheel hub mount positioned between the proximal and distal ends, configured to rotatably attach the wheel hub of the trailer wheel.

[0023] The side frames may further include removable rectangular cover plates enclosing the risers and crossbar on the outer side of the trailer wheels, providing protection and enhancing the aesthetic appearance of the trailer.

[0024] The floor of the cargo tray may be configured to lie flat on the ground in the lowered position, simplifying cargo loading and unloading and improving operational convenience.

[0025] According to another aspect, there is provided a method of using a level lift trailer, the trailer comprising a chassis and a cargo tray with slide track bearings slidably coupling the cargo tray to the chassis between raised and lowered positions, the method comprising: positioning the trailer in a stationary location; sliding the cargo tray along the slide track bearings from the raised position to the lowered position; loading cargo onto the cargo tray in the lowered position; sliding the cargotray along the slide track bearings from the lowered position to the raised position; and transporting the trailer with the cargo tray in the raised position.

[0026] This method provides a straightforward and efficient process for loading and unloading cargo, while the sliding movement facilitated by the slide track bearings ensures smooth and stable transitions between the raised and lowered positions. The ability to position the cargo tray flat on the ground in the lowered position enhances ease of use, particularly for heavy or wheeled cargo.

[0027] Other aspects of the invention are also disclosed.Brief Description of the Drawings

[0028] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0029] Figure 1 shows a rear perspective view of a level lift trailer in a raised position;

[0030] Figure 2 shows a rear perspective view of the level lift trailer in a lowered position;

[0031] Figure 3 shows a side view of the level of trailer in the raised position;

[0032] Figure 4 shows a side view of the level lift trailer in the lowered position;

[0033] Figure 5 shows a swing arm of a suspension assembly in accordance with an embodiment;

[0034] Figure 6 shows a perspective view of the suspension assembly; and

[0035] Figure 7 shows a perspective view of the cargo tray, slide bearings and suspension assembly.Description of Embodiments

[0036] Figure 1 shows a rear top perspective view of a level lift trailer 100 in accordance with an embodiment. The trailer 100 comprises a chassis 101 and a cargo tray 102, with slide track bearings 103 slidably coupling the cargo tray 102 to the chassis 101. The cargo tray 102 is movable between a raised position, shown in Figure 3, and a lowered position, shown in Figure 4. The cargo tray 102 remains in the raised position during transportation and is lowered to the lowered position whenstationary for convenient cargo loading. The cargo tray 102 may define a floor 104 with sidewalls 105. In the lowered position, the floor 104 may lie flat on the ground.

[0037] The chassis 101 comprises side frames 106, each defining a raised wheel arch frame 107. The chassis 101 may further include a front crossbar 108 connecting the front ends of the side frames 106. A towing wishbone 109 with a hitch mount 1 10 may extend forward of the front crossbar 108.

[0038] The trailer 100 comprises suspension assemblies 1 1 1 , best shown in Figure 6, interfacing with the respective wheel arch frames 107. The raised wheel arch frames 107 are structurally reinforced to support the suspension assemblies 1 1 1.

[0039] The suspension assemblies 1 1 1 support the trailer wheels 1 12 in a manner unconstrained by the side frames 106. Specifically, with reference to Figure 3, a hub 1 13 of each wheel 1 12 may be positioned beneath the side frames 106 when the suspension assembly 1 1 1 is uncompressed but may travel into the void defined by the wheel arch 107 when compressed under load or during road undulations.

[0040] Each suspension assembly 1 1 1 comprises a swing arm 1 14, best shown in Figure 5. The swing arm 1 14 is pivotally coupled at its proximal end 1 15 to a respective side frame 106 and compresses a compression member 1 17 from its distal end 1 16. Preferably, the proximal end 1 15 is positioned forward of the distal end 1 16 with respect to the trailer's direction of travel.

[0041] The swing arm 1 14 is configured to engage a respective trailer wheel 1 12 between its proximal end 1 15 and distal end 1 16. As shown in Figure 5, the swing arm 1 14 may include a wheel hub mount 1 18 between its proximal and distal ends, which is configured to rotatably attach the wheel hub 1 13.

[0042] Each side frame 106 supports a pair of slide track bearings 103 positioned fore and aft of each respective wheel arch frame 107. Each slide track bearing 103 comprises an angled track channel 1 19 affixed to a respective side of the cargo tray 102. With reference to Figure 7, these angled track channels 1 19 may be C-channels defining an outwardly facing open channel that is closed at its terminal ends. Each slide track bearing also comprises a bearing 120, preferably a roller bearing, engaged within the angled track channel 1 19 and affixed to the side frames 106. With referenceto Figure 3, the angled track channels 1 19 may be angled forward so that the cargo tray 102 descends rearwardly, as shown in Figure 4.

[0043] The dual slide track bearings 103 support the cargo tray 102 level fore and aft of the wheel arch frame 107 during raising and lowering, providing stable engagement centred around the wheel hub 1 13 during transportation.

[0044] With reference to Figure 4, the raised wheel arch frame 107 may define a fore riser 121 A and an aft riser 121 B, with a raised crossbar 122 connecting their upper ends. The side frames 106 may comprise lower frame portions 123 connecting the lower ends of the risers 121. In the embodiment shown, the trailer 100 comprises a fore lower frame portion 123A and an aft lower frame portion 123B with respect to the raised wheel arch frame 107. However, in some embodiments, the trailer 100 may omit the aft lower frame portion 123B.

[0045] Angle bracing 124 may strengthen the connections between the risers 121 and the crossbar 122. Rectangular cover plates 137, preferably removable, may enclose the risers 121 and the crossbar 122 on the outer side of the wheel 1 12.

[0046] Preferably, the swing arm 1 14 is pivotally coupled to one of the risers 121 , such as the fore riser 121 A. With reference to Figure 5, the swing arm 1 14 may be downwardly curved between its proximal end 1 15 and distal end 1 16 to position the hub 1 13 beneath the pivot point at its proximal end 1 15. The swing arm 1 14 may comprise a proximal bar 125A connected to a distal bar 125B at an angle.

[0047] With reference to Figure 2, the swing arm 1 14 may be located on the inside of its respective trailer wheel 1 12, providing accessible exposure to the hub 1 13 for maintenance or similar purposes. With reference to Figure 5, the distal end 1 16 may comprise a laterally projecting bar 126 that, with reference to Figure 4, reciprocates between the wheel 1 12 and the adjacent riser 121 B. This laterally projecting bar 126 enables the swing arm 1 14 to be positioned on the inner side of the wheel 1 12, providing a base to support the compression member 1 17.

[0048] In the preferred embodiment shown, the swing arm 1 14 acts on both a gas or spring compression strut 1 17A and a pneumatic airbag 1 17B. The laterally projecting bar 126 may include a flanged pin connector 127 for the compression strut 1 17A andan adjacent post 128 for the pneumatic airbag 1 17B. Similarly, the proximal end 1 15 may include a laterally projecting pin 129 configured to pivotally engage a collar 130 connected to an adjacent riser 121.

[0049] With reference to Figure 1 , the trailer 100 may include a winch box 130 supported on the wishbone 109, housing an electric winch operating via a winch cable 131. The winch cable 131 may feed over a pulley wheel 136. The electric winch 130 may operate from a vehicle's electrical supply, such as a 12V supply, or from a separate battery contained within the winch box 130.

[0050] The side frames 106 may include locking pins 132, which engage aligned apertures 133 on the sides of the cargo tray 102 when in the raised position to secure it. In the embodiment shown, these locking pins 132 are rearwardly located. Additionally, the trailer 100 may include front locking tabs 134, aligning with corresponding apertures 135 on the front edge of the cargo tray 102. A wingnut, locking pin, or similar fastener may secure the tray in position.

[0051] The cargo tray 102 may include a tailgate 134 hingedly coupled to the floor 104, movable between raised and lowered positions as shown in Figures 3 and 4, respectively. The tailgate 134 may be wedge-shaped to minimise the on-ramp edge into the cargo tray 102. With reference to Figure 2, the tailgate 134 may be supported by wedge-shaped bracing 135.

[0052] An exemplary method of using the level lift trailer 100 in accordance one embodiment is as follows: To load cargo onto the trailer 100, the user first positions the trailer 100 in a stationary location and ensures it is securely connected to a towing vehicle via the hitch mount 1 10 of the towing wishbone 109. The user then disengages the locking pins 132 from the aligned apertures in the sides of the cargo tray 102 and releases any fasteners securing the front locking tabs 134 to their corresponding apertures 135.

[0053] The winch box 130 is activated to lower the cargo tray 102 to the ground. This is accomplished by extending the winch cable 131 , which controls the movement of the cargo tray 102 along the slide track bearings 103. As the cargo tray 102 slides rearwardly along the angled track channels 1 19, it descends to the lowered position,where the floor 104 lies flat on the ground as shown in Figure 4. The wedge-shaped tailgate 134, if in the raised position, may be lowered to provide a smooth on-ramp edge for loading cargo.

[0054] Once the cargo is loaded onto the floor 104, the tailgate 134 may be raised and secured in position, supported by the wedge-shaped bracing 135. The winch box 130 is then activated in the reverse direction to retract the winch cable 131 and raise the cargo tray 102 back to the raised position as shown in Figure 3. The slide track bearings 103 guide the cargo tray 102 smoothly along the side frames 106, maintaining a level orientation fore and aft of the wheel arch frames 107 during movement.

[0055] When the cargo tray 102 reaches the raised position, the locking pins 132 are re-engaged with the aligned apertures in the sides of the cargo tray 102. The front locking tabs 134 are aligned with the apertures 135 and secured with a wingnut or similar fastener to prevent movement during transportation.

[0056] During transportation, the suspension assemblies 1 1 1 allow the trailer wheels 1 12 to traverse road undulations by compressing or extending within the voids defined by the raised wheel arch frames 107, as shown in Figure 3. The swing arms 1 14 pivot about their proximal ends 1 15 to accommodate these movements, while the compression members 1 17 dampen shocks and maintain stability.

[0057] To unload the cargo, the process is reversed. The locking pins 132 and front locking tabs 134 are disengaged, and the winch box 130 is operated to lower the cargo tray 102 to the ground. The tailgate 134 may be lowered to allow cargo to be unloaded efficiently. After unloading, the cargo tray 102 is raised and locked in position as described above, ready for further use or transportation.

[0058] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practise the invention. Thus, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed asobviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

Claims

Claims1 . A level lift trailer comprising: a chassis and a cargo tray with slide track bearings slidably coupling the cargo tray to the chassis between raised and lowered positions, wherein: the chassis comprises side frames, each defining a raised wheel arch frame; suspension assemblies interfacing respective wheel arch frames, each suspension assembly comprising a swing arm: pivotally coupled at a proximal end to a respective side frame, compressing a compression member connected between a distal end of the swing arm and the raised wheel arch frame, and configured for engaging a trailer wheel between the proximal and distal ends; each side frame supports a pair of the slide track bearings fore and aft of its respective wheel arch frame, each slide track bearing comprising: an angled track channel affixed to a respective side of the cargo tray, and a bearing engaged within the angled track channel and affixed to the side frame.

2. The level lift trailer of claim 1 , wherein the raised wheel arch frame defines fore and aft risers and a raised crossbar therebetween.

3. The level lift trailer of claim 2, further comprising angle bracing between the risers and the crossbar.

4. The level lift trailer of claim 1 , wherein the compression member is connected to the raised crossbar.

5. The level lift trailer of claim 1 , wherein the swing arm is pivotally coupled to one of the risers.

6. The level lift trailer of claim 1 , wherein the swing arm is downwardly curved between the proximal and distal ends.

7. The level lift trailer of claim 1 , wherein the swing arm is located on the inside of its respective trailer wheel.

8. The level lift trailer of claim 1 , wherein the distal end of the swing arm comprises a laterally projecting bar configured to reciprocate between the wheel and an adjacent riser.

9. The level lift trailer of claim 8, wherein the laterally projecting bar engages a plurality of compression members.

10. The level lift trailer of claim 9, wherein the plurality of compression members comprises a compression strut and a pneumatic airbag.1 1 . The level lift trailer of claim 1 , wherein the proximal end of the swing arm comprises a laterally projecting pin configured to pivotally engage a collar connected to an adjacent riser.

12. The level lift trailer of claim 1 , wherein the angled track channel is a C-channel defining an outwardly facing open channel that is closed at its terminal ends.

13. The level lift trailer of claim 1 , wherein the angled track channels are angled forward such that the cargo tray descends rearwardly during movement to the lowered position.

14. The level lift trailer of claim 1 , further comprising locking pins located rearwardly on the side frames, configured to engage aligned apertures in the cargo tray to secure the cargo tray in the raised position.

15. The level lift trailer of claim 14, further comprising front locking tabs aligned with corresponding apertures across a front edge of the cargo tray and configured to secure the cargo tray in the raised position with a fastener.

16. The level lift trailer of claim 1 , further comprising an electric winch operable to raise and lower the cargo tray via a winch cable.

17. The level lift trailer of claim 16, wherein the winch cable is configured to feed over a pulley wheel to control the movement of the cargo tray.

18. The level lift trailer of claim 16, wherein the electric winch is operable from at least one of a vehicle's electrical supply and a separate battery contained within the winch box.

19. The level lift trailer of claim 1 , wherein the cargo tray further comprises a tailgate hingedly coupled to the floor and movable between raised and lowered positions.

20. The level lift trailer of claim 19, wherein the tailgate is wedge-shaped.21 . The level lift trailer of claim 20, wherein the tailgate is supported by wedge- shaped bracing.

22. The level lift trailer of claim 1 , wherein the suspension assemblies are configured to allow a wheel hub of each trailer wheel to travel into the void defined by the raised wheel arch frame when the suspension assembly is compressed.

23. The level lift trailer of claim 1 , wherein the swing arm comprises a wheel hub mount positioned between the proximal end and distal end of the swing arm and configured to rotatably attach the wheel hub of the trailer wheel.

25. The level lift trailer of claim 2, wherein the side frames further comprise removable rectangular cover plates enclosing the risers and crossbar on the outer side of the trailer wheels.

26. The level lift trailer of claim 1 , wherein a floor of the cargo tray is configured to lie flat on the ground in the lowered position.

27. A method of using a level lift trailer as defined in claim 1 , comprising: positioning the trailer in a stationary location; sliding the cargo tray along the slide track bearings from the raised position to the lowered position; loading cargo onto the cargo tray in the lowered position; sliding the cargo tray along the slide track bearings from the lowered position to the raised position; and transporting the trailer with the cargo tray in the raised position.

28. The method of claim 27, further comprising: lowering a wedge-shaped tailgate hingedly coupled to the floor of the cargo tray to provide a smooth on-ramp for loading cargo; raising the tailgate after loading the cargo; and securing the tailgate in the raised position.

29. The method of claim 27, wherein the step of sliding the cargo tray includes guiding the tray along angled track channels, such that the tray descends rearwardly when moving to the lowered position and ascends forwardly when moving to the raised position.

30. The method of claim 27, wherein the suspension assemblies accommodate road undulations during transportation by their swing arms enabling wheel hubs to travel into voids defined by the raised wheel arch frames.

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