Patent Description:
A longstanding safety problem exists in the use of dump trailers that tilt to discharge their cargo. In these vehicles, the bed tilts relative to the chassis frame that supports the bed. Raising the bed to discharge material alters the center of gravity of the trailer and accompanying truck, such that the truck and trailer combination may be prone to tipping if this is done on an uneven surface. There are also environments of use where raising the bed is impossible or risky, especially where there are overhead powerlines or overhanging structure such as the deck of a house or a rock ledge. Additionally, there is an emerging market for compact construction equipment, which is not easily able to use traditional dump trucks or trailers due to the height of such dump trucks and trailers.

Dump trailers with ejectors have been provided, but typically also have a high profile and center gravity. There is a need for a new dump trailer that overcomes the foregoing disadvantages, particularly with respect to compact construction equipment. Documents <CIT> and <CIT> disclose some relevant prior art.

The present invention provides a low profile dump trailer for use with a tractor unit having at least one rear wheel and axial assembly with left and right wheels, as set out in claim <NUM>. Further features of the invention are set out in the dependent claims.

The dump trailer of the invention is for use with any suitable motive means, for example a vehicle of any suitable type such as a tractor unit or truck having at least one rear wheel and axle assembly with left and right wheels. The dump trailer can be used for hauling any type of cargo. Such cargo can optionally include rock, gravel, scrap iron, dirt, soil, tar, asphalt, sand, construction materials, trash, debris, demolition debris, broken concrete, materials derived from demolition, garbage, agricultural commodities, agricultural waste or any combination of the foregoing.

The dump trailer can be loaded by any suitable means, including manually or by construction loading equipment. The construction loading equipment can be of any suitable type, for example an excavator, a track loader, a backhoe, a bucket loader, a front loader, a front-end loader, a payloader, a scoop, a shovel, a skip loader, a wheel loader or a skid-steer.

The dump trailer includes a suitable coupling or forward extension of any suitable type, which can be called a goose neck or nose, for removable coupling the dump trailer to the truck tractor or other motive means. A frame, which can be called a framework, a support frame or a chassis support frame, is joined to the forward extension and extend rearwardly of the forward extension. The frame has a front and a rear and a top and a bottom. The frame is a dropped frame, for example be lower in height than the forward extension. A plurality of trailer wheel and axle assemblies, which can be called wheel/axle assemblies, are joined to the bottom of the rear of the frame. Each of the plurality of trailer wheel and axle assemblies has at least left and right wheels suitable for highway travel. An open bed is joined to the top of the frame for receiving cargo, for example from the construction loading equipment. The open bed has a front and a rear opening for permitting discharge of the cargo from the open bed. The open bed can be of a rectangular cross section or an open half cylinder with a semicircular cross section.

The dump trailer is referred to as a low-profile dump trailer or a dropped frame dump trailer. When the frame is a dropped frame, at least a portion of the open bed can optionally extend at a height below the height of the forward extension. For example, the entire open bed can optionally be lower than the forward extension, at least <NUM>% of the open bed can optionally be lower than the forward extension, at least <NUM>% of the open bed can optionally be lower than the forward extension, at least <NUM>% of the open bed can optionally be lower than the forward extension, at least <NUM>% of the open bed can optionally be lower than the forward extension or at least <NUM>% of the open bed can optionally be lower than the forward extension. The open bed can optionally have a top height above ground approximating the height of the forward extension.

The open bed of the dump trailer can have any suitable top height, that is relative to the ground, for example between <NUM> and <NUM> (five and six feet), <NUM> (<NUM> feet (<NUM> inches)), <NUM> (<NUM> feet (<NUM> inches)), <NUM> (<NUM> feet (<NUM> inches)), <NUM> (<NUM> feet (<NUM> inches)) or <NUM> (<NUM> feet (<NUM> inches)). The open bed of the dump trailer can have any suitable bottom height, for example ranging from <NUM> to <NUM> (<NUM> to <NUM> inches).

The open bed of the dump trailer can have any suitable length, width and dimension. The open bed can optionally have an internal height of <NUM> (<NUM> inches) and an internal width of <NUM> (<NUM> inches). The open bed can optionally have an internal length to its rear opening of <NUM> (<NUM> inches), without inclusion of a dump mechanism within the open bed. The open bed can optionally have a length, measured from the face of a dumping blade within the open bed to the rear opening of the open bed of <NUM>, <NUM> or <NUM> (<NUM> inches, <NUM> inches or <NUM> inches).

The open bed can have a length and a height relative to the ground and any suitable length to height ratio, for example <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, ranging from <NUM>:<NUM> to <NUM>:<NUM> or ranging from <NUM>:<NUM> to <NUM>:<NUM>.

The open bed can have a load capacity at water level ranging from <NUM> to <NUM> cubic metres (<NUM> to <NUM> cubic yards).

The open bed can have a load capacity in cubic yards at water level and a height in feet and any suitable load capacity to height ratio, for example <NUM>:<NUM> (for example <NUM> cubic metres (<NUM> cubic yards) with <NUM> (<NUM> inch height)), <NUM>:<NUM>, <NUM>:<NUM> or ranging from <NUM>:<NUM> to <NUM>:<NUM>. The dump trailer can optionally have a maximum achievable payload exceeding <NUM> (<NUM>,<NUM> pounds) when the top height of the open bed is between <NUM> and <NUM> (five to six feet) above the ground.

The open bed can have a bottom that is positioned above the left and right wheels of the trailer wheel and axle assemblies by any suitable distance, for example <NUM> (<NUM> inch), <NUM> (<NUM> inch) or ranging from <NUM> to <NUM> (<NUM> to <NUM> inches).

Where the dump trailer is used with a tractor unit or truck having at least left and right rear wheels having a new tire diameter, the left and right wheels of the trailer wheel and axle assemblies of the dump trailer can each optionally have a new tire diameter that is any suitable percentage of the new tire diameter of the left and right rear wheels of the tractor unit, for example <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% of the new tire diameter of the left and right rear wheels of the tractor unit. The left and right wheels of the trailer and wheel assemblies of the dump trailer can optionally be smaller in diameter, size or both than the left and right rear wheels of the tractor unit.

The left and right wheels of the trailer wheel and axle assemblies of the dump trailer can optionally have a new tire diameter of <NUM> (<NUM> inches) or ranging from <NUM> to <NUM> (<NUM> to <NUM> inches).

The dump trailer of the invention optionally includes a dump mechanism of any suitable type for emptying the open bed of the trailer. For example, the open bed can be tiltably coupled to the rear of the trailer frame and the dump mechanism can optionally include an actuator joined to the front of the frame and the open bed for tilting the front of the open bed upwardly relative to the frame for emptying the open bed. When the open bed is not tiltably coupled to the frame, but instead for example is fixed at its front and rear to the frame, the dump mechanism can optionally include a blade slidably disposed within the open bed and an actuator joined to the blade for urging the blade rearwardly within the open bed towards the rear opening for emptying the open bed. The blade can extend any suitable percentage of the length of the open bed, for example the interior length of the open bed, between is fully retracted position and its fully extended position, for example, <NUM>%, <NUM>% , <NUM>% or <NUM>% of the length of the open bed. The actuator can optionally be disposed within the forward extension of the dump trailer, for example a goose neck of the trailer. In this regard, the actuator can optionally be disposed within the confines of the forward extension, for example the gooseneck, so as to not extend above the trailer. The actuator can optionally be nested within the forward extension.

The dump trailer includes a chassis support frame that supports an open-top bed, which can optionally be coupled in a substantially fixed relationship to the chassis support frame to prevent tilting of the open-top bed relative to the chassis support frame. The open-top bed optionally has a tailgate opening at the rear of the open-top bed. The optional tailgate can optionally be selectively positionable between a closed configuration covering the tailgate opening and an open configuration away from the tailgate opening. A nose, gooseneck or forward extension is coupled to the chassis frame and extends forward of the bed. The nose, or gooseneck, has a trailer hitch connector for coupling the trailer to a truck tractor unit or other suitable vehicle. The nose, or gooseneck, can optionally support a hydraulic cylinder that is arranged for selective extension and retraction movement along a longitudinal path of travel between forward and rearward positions along the bed. A blade is optionally coupled with the hydraulic cylinder for motion along the path of travel concomitant with the selective extension and retraction movement such that rearward extension of the hydraulic cylinder when cargo is in the bed pushes the cargo from the bed and through the tailgate opening. At least one wheel assembly is coupled to the bottom of the chassis support frame for support thereof and permitting movement of the dump trailer along a transportation network.

The bed may optionally be provided with right and left sidewalls running in parallel to the longitudinal path of travel of the dump trailer. Each of the opposed sidewalls may optionally have a guide rail running in parallel to the longitudinal path of travel, for example down the length of the sidewall. The blade optionally has a right lateral edge facing the right sidewall and a left lateral edge facing the left sidewall. The left lateral edge of the blade can optionally define a recess of complimentary dimensions for receipt of the guide rail on the left sidewall. The right lateral edge can optionally define a recess of complimentary dimensions for receipt of the guide rail on the right sidewall. This structure advantageously permits the guide rails to stabilize the blade during travel of the blade down the bed, for example when discharging cargo from the bed. The blade stabilization can optionally be further enhanced by tilting the bottom of the blade rearward out from the top and by providing the blade with a concave rearward facing surface. For example, each guide rail can optionally be provided with a downwardly extending ridge along its length for engaging an upwardly extending lip or protuberance on the respective side of the blade.

The trailer hitch connector may optionally be a king pin for a fifth wheel connector where the hitch is composed of a kingpin on the trailer and a fifth-wheel on a truck tractor. The dump trailer may optionally be constructed for a maximum achievable payload exceeding <NUM> (<NUM>,<NUM> pounds) when the trailer is limited to a height of <NUM> (<NUM> feet <NUM> inches) where regulations prescribe a gross combination weight (tractor and trailer) of <NUM> (<NUM>,<NUM> pounds). While a lower height can be particularly advantageous, in other applications the dump trailer may be, for example, limited to a maximum height of <NUM> (<NUM> feet) or maximum height of regulatory agency requirements, such as those for state and federal motor carriers.

The dump trailer may optionally be used in a method of dumping. The dump trailer may optionally be coupled to a motive means, such as a truck or tractor unit. The bed of the trailer can be filled with cargo, such as sand, rock, asphalt, broken concrete, materials derived from demolition, garbage, agricultural commodities, agricultural waste, construction equipment, dirt or scrap iron. Suitable construction loading equipment can be utilized for loading the dump trailer, for example an excavator, a track loader, a backhoe or other construction equipment small enough to fit within the cargo area. The bed can optionally be loaded when the blade resides at a forward position in the bed and the tailgate is in a closed configuration. The motive means can be driven with the dump trailer attached to haul the cargo from a first location to a second location. A hydraulic cylinder can optionally be provided in the dump trailer and actuated at the second location to move the blade rearward with concomitant discharge of the cargo. The tailgate can optionally be opened by the discharged cargo or mechanically by any suitable actuation means carried by dump trailer and coupled to the tailgate.

The embodiments of the invention set forth herein, for example below, are examples of the invention, and may in some instances be broader or narrower than the foregoing discussion of the invention but are not intended to limit the breadth of the invention. Any additional features of the invention set forth in such embodiments are optional. A feature of any embodiment set forth herein can optionally be combined with any other embodiment of the invention, with or without any other feature of any embodiment set forth herein. All characteristics, steps, parameters and features of the methods below are not limited to the specific embodiments or specific parts set forth below, but instead can optionally be applicable to the foregoing discussion of the invention and to all embodiments of the invention. Broad terms and descriptors are sometimes replaced with more specific terms and descriptors herein not to limit a disclosure to a specific term or descriptor but merely for ease of discussion and understanding.

An embodiment of a dump trailer of the invention is illustrated in <FIG>. Dump trailer <NUM> therein, which can optionally be referred to as an ejector-dump trailer <NUM>, includes a structural frame <NUM> including an upper rectangular frame section <NUM> and a lower rectangular frame section <NUM>. The upper and lower rectangular frame sections <NUM>, <NUM> are optionally reinforced by vertical medial posts <NUM> and similar posts <NUM>, <NUM>, <NUM>, <NUM> at each corner. Sidewalls S1 (right) and S2 (left) are formed from steel panels <NUM>, <NUM>, <NUM>, <NUM> that may be bolted, riveted, welded or otherwise suitably jointed to the frame <NUM>. A planar bottom <NUM> is formed of welded sheet steel panels. The frame <NUM> is mounted to a chassis support frame (not shown) to which are connected wheel/axle assemblies <NUM>, <NUM>, <NUM>, which can optionally be referred to as wheel and axle assemblies, by use of suspension mounts (not shown). A front wall <NUM> and optional tailgate <NUM> define an open-top cargo bed <NUM> that, in use, may be filled with any material that is capable of being hauled by a dump truck, such as rock, gravel, scrap iron, dirt, asphalt, sand, trash, debris, demolition debris or construction material. Although cargo bed <NUM> is shown as being a box bed, it may be semicircular or any other suitable shape in cross section.

The bottom <NUM> is optionally coupled to the chassis support frame (not shown) in such a manner as to prevent substantial tilting, as for example would be needed to empty the cargo bed <NUM> in a trailer that dumps by raising the elevation of the front wall <NUM> to cause the cargo to slide rearward under the tailgate <NUM> when the tailgate <NUM> is open. The ejector-dump trailer <NUM> does not operate in this tilting manner. A telescoping hydraulic cylinder <NUM> is optionally pivotally attached, such as by lateral pinning, to a cross-wall <NUM> and a receptacle <NUM> in blade <NUM> such that selective actuation of the telescoping hydraulic cylinder <NUM> extends and retracts the blade <NUM> on path <NUM> with sufficient force to discharge cargo from the cargo bed <NUM> and then retract the blade <NUM> to a position proximate the front wall <NUM>. One or more safeguards may optionally be built into the telescoping hydraulic cylinder <NUM>, such as an internal hydraulic vent port opening (not shown) that prevents extension past the tailgate <NUM>, and another that prevents an undue extent of contraction proximate the front wall <NUM>.

Slots <NUM> in the side of blade <NUM> have complimentary dimensions for receipt and engagement with a pair of opposed optionally guide ribs or rails <NUM> that can be mounted on the sidewalls S1, S2 to prevent or mitigate the bottom edge <NUM> of the blade <NUM> from overriding cargo in the cargo bed <NUM> as the blade travels rearward on path of travel <NUM>. The blade <NUM> is tilted at an angle β that places the bottom edge <NUM> rearward of top edge <NUM>. Use of the guides <NUM> in combination with rearwardly concave curvature of a rearward surface <NUM> on the blade <NUM> generally force the bottom edge <NUM> of the blade <NUM> downward into engagement with the upper surface of the bottom wall <NUM> to provide a scraping effect that closely removes cargo from atop the bottom wall <NUM> as the blade <NUM> is rearwardly extended. It will be appreciated that the path of travel <NUM> runs in parallel with the guide rails <NUM>, and that these guiderails stabilize the blade <NUM> to prevent undue wear of the blade <NUM> and bed.

The bottom rectangular frame section <NUM> extends forward to facilitate rigid attachment of a nose <NUM>, which can be referred to as a gooseneck or forward coupling extension, that optionally provides a mounting platform for the telescoping hydraulic cylinder <NUM> using cross-wall <NUM>, as described above. The nose <NUM> is optionally formed of a generally L-shaped frame <NUM> that rises from the bottom rectangular frame section <NUM> and then extends horizontally towards the front to present a fifth-wheel hitch component <NUM> at a suitable height for attachment to a semi-tractor. The cargo bed <NUM> of ejector-dump trailer <NUM> can optionally approximate the cargo bed of a normally sized rear-tilting dump truck, but advantageously has approximately half the height profile of that class of dump truck. Depending upon the scale of the ejector-dump trailer <NUM>, other hitches may suffice, such as a goose-neck or ball hitch (not shown) in place of the fifth wheel hitch component <NUM>.

The ejector-dump trailer <NUM> optionally has certain conventional features, such as lights <NUM> mud flaps <NUM>, <NUM>, and bumper <NUM>. The tailgate <NUM> optionally has opposed barrel latches <NUM>, <NUM> that may be unlatched, permitting the tailgate <NUM> to pivot from a top axis to travel on arc <NUM> terminating where locking hydraulic tailgate lifters equipped with safety valving <NUM>, <NUM> retain the tailgate <NUM> in a generally horizontal configuration that is substantially aligned with the top surface of the bottom <NUM> for ease of discharge. An optional forward mud flap <NUM> can be provided. A ladder rung <NUM> optionally drops down proximate the front wall <NUM> to facilitate access for maintenance of the blade <NUM> and the telescoping hydraulic cylinder <NUM>.

A space <NUM> can optionally be provided between the rear of the blade <NUM> and the front wall <NUM>. At the bottom of this space can be an optional opening (not shown) that discharges into a collection pan <NUM> that is configured laterally with a hinge and a retainer pin for cleanout. The opening and collection pan <NUM> are optionally provided for removal of cargo, such as debris, that may become trapped between the front wall <NUM> and the blade <NUM>.

<FIG> shows the front end <NUM> of the ejector-dump trailer <NUM> with the blade <NUM> and the telescoping hydraulic cylinder <NUM> removed to reveal an opening <NUM> in the front wall, <NUM> that permits passage of the telescoping hydraulic cylinder <NUM> through the front wall <NUM>. <FIG> also shows an optional opening <NUM> that discharges into the collection pan <NUM> for cleanout of space <NUM> (see <FIG>). The nose <NUM> optionally contains mounting boxes <NUM>, <NUM> that may be used for mounting a hydraulic pump with associated manual controls, as well as a tank for hydraulic oil and tools.

<FIG> is a top plan view of the ejector-dump trailer <NUM> showing an optional pair of opposed trusses <NUM>, <NUM>. The trusses <NUM>, <NUM> extend from a cross-wall <NUM> that is forward of the cross-wall <NUM> to which the telescoping hydraulic cylinder is anchored, and travel rearwardly while narrowing towards a longitudinal axis <NUM> in support of the cross-wall <NUM>. As shown in <FIG>, the path of travel <NUM> of blade <NUM> may run almost the full or the full length L of the bed <NUM>. This is because the hydraulic cylinder <NUM> can be optionally mounted on the nose <NUM>, which permits the rear of blade <NUM> to reside in close proximity to the front wall <NUM>, and may even abut the front wall <NUM>. The path of travel <NUM> may traverse, for example, <NUM>%, <NUM>%, <NUM>% or <NUM>% of the length L extending between the front wall <NUM> and the tailgate <NUM>.

As shown in <FIG>, the optional tailgate <NUM> can be moved to a closed configuration <NUM> that covers an opening <NUM> at the rear of the bed <NUM>. The closed configuration <NUM> prevents or mitigates spillage of cargo from within the bed <NUM> in the intended environment of use. The tailgate <NUM> is selectively repositionable to an open configuration where the tailgate <NUM> is removed from the opening <NUM> to permit discharge of cargo from the bed <NUM> by virtue of the action of blade <NUM>. The tailgate <NUM> may optionally be constructed to pivot in proximity to the bottom <NUM> such that the tailgate either drops to a vertical position generally lower than the bottom <NUM>, or the tailgate <NUM> may be retained by hydraulics (not shown) or chains and the like to extend horizontally and in parallel to the bottom <NUM> as represented by position <NUM>. When the tailgate is designed for this type of horizontal positioning, the path of travel <NUM> may exceed the total length L of the bed <NUM> as the blade traverses out over the horizontally extended tailgate <NUM>.

The dump trailer may be provided with other tailgate configurations including , for example, two door style tailgates with hinges on opposing ends, single door style with hinges on one side, a folding ramp style tailgate to facilitate equipment loading, or a hydraulic lift tailgate. Alternately, the dump trailer may be offered without a tailgate.

<FIG> is a bottom plan view of the of the ejector-dump trailer <NUM> showing airadjustable shock suspension systems <NUM>, <NUM>, <NUM>, each comprised of a pair of air shocks <NUM>, <NUM> in opposing front-rear orientations, together with suspension assemblies <NUM>, <NUM> coupling the wheel/axle assemblies <NUM>, <NUM>, <NUM> with longitudinally extending chassis support frame members <NUM>, <NUM>. The chassis support frame <NUM> includes also lateral cross-members <NUM>, <NUM><NUM>, <NUM>, which support the bottom rectangular frame section <NUM> of the bed <NUM>. The lateral cross-members <NUM>, <NUM>, <NUM>, <NUM> are rigidly affixed to the chassis frame members <NUM>, <NUM> and the bottom rectangular frame section <NUM> such that the bed <NUM> does not tilt relative to the chassis frame member <NUM>, <NUM>. In like manner, the chassis frame members and the bed <NUM> do not tilt relative to the wheel/axle assemblies are <NUM>, <NUM>, <NUM>, which are located on the rear half of the ejector-dump trailer <NUM>. While the trailer depicted in <FIG> is an air-ride trailer, other suspensions such as spring and trunnion suspensions may be utilized.

<FIG> is a side plan view of the ejector-dump trailer <NUM> that provides additional detail regarding the manner of attaching the L-shaped nose <NUM> to the ejector-dump trailer <NUM>. An optional first steel plate bracket <NUM> is bolted or riveted or welded to the chassis frame member <NUM> and a riser <NUM>. An optional second steel plate <NUM> couples the riser <NUM> with a horizontal forward extension frame member <NUM>. An optional vertical post <NUM> may be a tubular member of square or circular cross-section, and this may be supported by a brace <NUM>. The vertical post <NUM> telescopingly receives an optional extensible foot <NUM> that may be extended and retracted by select actuation of a hydraulic cylinder or a handcranked gear assembly in the nature of a jack (not shown). The extensile foot <NUM> supports the front end <NUM> of the ejector-dump trailer <NUM> when the trailer is not attached to a truck or tractor unit for hauling operations.

<FIG> shows the ejector-dump trailer <NUM> with the fifth wheel connector <NUM> engaging a fifth wheel coupling <NUM>, or other suitable coupling mechanism, that is mounted at the rear of a tractor unit or truck <NUM> of any suitable type. Tractor unit <NUM> can include a frame <NUM> carrying a cab <NUM> for housing the driver. Steerable front wheels <NUM> are rotatably carried by the front of frame <NUM> and at least one rear wheel and axle assembly <NUM> is rotatably carried by the rear of frame <NUM>. The rear wheel and axle assembly <NUM> can include left and right wheels <NUM>. The assembled tractor-trailer unit <NUM> is, accordingly, made ready for over-the-road hauling, for example on an outdoor transportation network.

An optional embodiment of the dump trailer of the invention is shown in <FIG>. Dump trailer <NUM> shown therein includes a high-strength frame <NUM> made from steel or any other suitable high-strength material. For example, the frame <NUM> can be formed from a plurality of members <NUM>, each made for example from steel, joined together to form a framework (see <FIG>, <FIG> and <FIG>). Frame <NUM> includes a main portion <NUM> and an extension <NUM> joined to the main portion and extending forwardly of the main portion. The extension <NUM>, which can be referred to as a gooseneck, includes a coupling mechanism <NUM>, such as a fifth wheel coupling mechanism, on its underside for removably coupling the trailer <NUM> to a complementary coupling mechanism provided on a tractor unit, for example coupling mechanism <NUM> of tractor unit <NUM>. Main portion <NUM>, which can optionally be planar, has a front 706a and a rear 706b and a top <NUM> and a bottom <NUM>.

A plurality of trailer wheel and axle assemblies <NUM> are joined to the bottom <NUM> of frame main portion <NUM> at its rear 706b by any suitable means, for example suspension and swingarm assemblies <NUM>. Each of the assemblies <NUM> can be of any suitable type and of any suitable number. Dump trailer <NUM> is shown with three wheel and axle assemblies <NUM> longitudinally spaced apart along the bottom <NUM> of frame main portion <NUM>. Each of the axle and wheel assemblies <NUM> includes a transverse axle <NUM> and at least one left wheel <NUM> and at least one right wheel <NUM>. Each of the assemblies <NUM> can optionally include a plurality, such as two, left wheels <NUM> and a plurality, such as two, right wheels <NUM>. Each of the wheels <NUM>,<NUM> includes a rim <NUM> and a tire <NUM> extending around the rim suitable for highway travel. It is appreciated that the number of wheels in each axle and wheel assembly <NUM>, and on trailer <NUM> is a function of a number of factors, including the load capacity of the trailer and the size of the tires.

The left and right wheels <NUM>,<NUM> of the trailer wheel and axle assemblies <NUM> can be of any suitable size. Wheels <NUM>, <NUM> to optionally be smaller in diameter, size or both than rear wheels <NUM> of tractor unit <NUM>. For example, wheels <NUM>, <NUM> can each optionally have a new tire diameter that is any suitable percentage of the new tire diameter of the left and right rear wheels <NUM> of the tractor unit <NUM>, for example <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% of the new tire diameter of the left and right rear wheels <NUM> of the tractor unit <NUM>. Wheels <NUM>, <NUM> can optionally have a new tire diameter ranging from <NUM> to <NUM> (<NUM> to <NUM> inches). Wheels <NUM>, <NUM> can optionally have a new tire diameter of <NUM> inches.

Each of the axle and wheel assembly <NUM> optionally includes a mechanism, such as at least one airbag (not shown), for example mounted between frame main portion <NUM> and the suspension assembly, for adjusting the height of the frame main portion <NUM> relative to the assembly <NUM>, and thus the wheels of the assembly. A plurality of brake chambers <NUM> are optionally included in dump trailer <NUM> for assisting in the braking of the trailer.

Dump trailer <NUM> as an open bed <NUM> joined to top <NUM> of frame main portion <NUM> for receiving the cargo to be carried by the trailer. Bed <NUM> can optionally extend the entire length of frame main portion <NUM>, for example between the front end and the rear end of the frame portion <NUM>, and optionally the entire width of frame main portion <NUM>, for example between the opposite left and right sides of the frame portion. Bed <NUM> can be of any suitable configuration and shape, for example rectangular in cross-section or semicircular in cross-section. The open bed <NUM> can be joined or secured to frame main portion <NUM> by any suitable means. Optionally, open bed <NUM> is made from metal or any other suitable material and is a box bed formed from a bottom wall <NUM> secured to top <NUM> of frame main portion <NUM>, left and right side walls <NUM> extending upwardly from opposite sides of the bottom wall <NUM> and a front wall <NUM> extending upwardly from the front end of bottom wall <NUM> and between the front end of side walls <NUM>. Each of the walls of the open bed <NUM> are optionally formed from a plurality of rigid frame members <NUM> joined together to form a rigid framework for the respective wall. For example, bottom wall <NUM> includes a plurality of frame members <NUM> extending transversely to the top <NUM> of frame main portion <NUM>, each of the side walls <NUM> includes a plurality of frame members <NUM> extend upwardly along each of the opposite sides of bottom wall <NUM> and the front wall <NUM> includes a plurality of frame members <NUM> extending upwardly from the front end of the bottom wall <NUM>. One or more layers <NUM> of any suitable rigid material such as steel or another metal forms the inside of open bed <NUM>, including on the inside of each of left and right sidewalls <NUM> and front wall <NUM> and the top of bottom wall <NUM>. Sidewalls <NUM>, front wall <NUM> and bottom wall <NUM> form an open space or cargo area <NUM> of the bed. The cargo area <NUM> communicates with an opening <NUM> at the back or rear of the open bed <NUM>.

Open bed <NUM> of the dump trailer <NUM> can have any suitable top height, that is relative to the ground or other support surface on which the trailer <NUM> is resting. In this regard, the top of open bed <NUM>, for example the top of sides walls <NUM> and front wall <NUM> of the bed <NUM>, can optionally be between <NUM> and <NUM> (five and six feet), <NUM> (<NUM> feet (<NUM> inches)), <NUM> (<NUM> feet (<NUM> inches)), <NUM> (<NUM> feet (<NUM> inches)), <NUM> (<NUM> feet (<NUM> inches)) or <NUM> (<NUM> feet (<NUM> inches)) above the ground. Open bed <NUM> can have any suitable bottom height. The bottom height of the open bed, for example the height of the inside of bottom wall <NUM> of the bed <NUM>, can optionally range from <NUM> to <NUM> (<NUM> to <NUM> inches) above the ground.

The length of open bed <NUM> relative to the top height of the open bed <NUM> can be any suitable ratio. For example, open bed <NUM> can optionally have a length to height ratio of <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, ranging from <NUM>:<NUM> to <NUM>:<NUM> or ranging from <NUM>:<NUM> to <NUM>:<NUM>.

The bottom of open bed <NUM> can be positioned above left and right wheels <NUM>, <NUM> of trailer wheel and axle assemblies <NUM> by any suitable distance. The example, left and right wheels <NUM>, <NUM> can optionally be spaced below the bottom of bottom wall <NUM> a distance of <NUM> (<NUM> inch), <NUM> (<NUM> inch) or ranging from <NUM> to <NUM> (<NUM> to <NUM> inches).

The load capacity in cubic yards at water level of open bed <NUM> relative to the top height in feet of the open bed can be any suitable ratio. For example, open bed <NUM> can optionally have a load capacity to height ratio of <NUM>:<NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM> or ranging from <NUM>:<NUM> to <NUM>:<NUM>. Dump trailer <NUM> can optionally have a maximum achievable payload exceeding <NUM> (<NUM>,<NUM> pounds) when the top height of the open bed <NUM> is between <NUM> to <NUM> (five to six feet) above the ground.

At least a portion of open bed <NUM> can optionally extend below forward extension <NUM> of frame <NUM>. In this regard, top <NUM> of frame main portion <NUM> can be disposed vertically below top <NUM> of forward extension <NUM>. Such a frame <NUM>, which can be referred to as a dropped frame, can optionally include an upstanding portion <NUM> extending upwardly at front end of frame portion <NUM> for joining the front 706a of frame main portion <NUM> to the rear of forward extension <NUM>. Upstanding portion <NUM> can optionally be formed from a plurality of frame members <NUM> and can optionally be substantially vertical so that front wall <NUM> of open bed <NUM> seats substantially flush with the upstanding portion <NUM>.

Dump trailer <NUM> can optionally be referred to as a low-profile dump trailer or a dropped frame dump trailer. When frame <NUM> is a dropped frame, at least a portion of open bed <NUM> can optionally extend at a height below the height of forward extension <NUM>. The entire open bed <NUM> can optionally be lower than the forward extension <NUM>. At least <NUM>% of open bed <NUM> can optionally be lower than forward extension <NUM>. At least <NUM>% of open bed <NUM> can optionally be lower than forward extension <NUM>. At least <NUM>% of open bed <NUM> can optionally be lower than forward extension <NUM>. At least <NUM>% of open bed <NUM> can optionally be lower than forward extension <NUM>. At least <NUM>% of open bed <NUM> can optionally be lower than forward extension <NUM>. Open bed <NUM> can optionally have a top height above ground, or other surface on which dump trailer <NUM> is resting, approximating the height of forward <NUM> extension.

Dump trailer <NUM> can include a dump mechanism <NUM> for emptying the contents of open bed <NUM>. The dump mechanism can be of any suitable type and can optionally include a blade, for example blade <NUM>, movable within open bed <NUM> towards rear opening <NUM> for emptying the contents or cargo within the open bed. Blade <NUM> can be made from any suitable rigid material such as metal. The blade can optionally be slidably or movably disposed within open bed <NUM>, for example along sidewalls <NUM> and bottom wall <NUM>, from a first position away from rear opening <NUM> to a second position closer to the rear opening. They dump mechanism <NUM> can be referred to as an ejecting mechanism or ejector.

Blade <NUM> can optionally include a central portion <NUM> closely approximating the cross-sectional shape and dimensions of open bed <NUM>. The central portion <NUM> can optionally be planar or concave towards rear opening <NUM>. Blade <NUM> can optionally include a bottom portion <NUM> inclined or inclinable forwardly of central portion <NUM> for engaging the bottom of open bed <NUM> and first and second side portions <NUM> inclined or inclinable forwardly of central portion <NUM> for engaging the sides of open bed <NUM>. Blade <NUM> can optionally include a top portion <NUM>, which can be referred to as a deflector, inclined forwardly of central portion <NUM>.

Bottom portion <NUM> can optionally be pivotable relative to blade central portion <NUM> from a first position in engagement with bottom wall <NUM> and a second position spaced away from the bottom wall. The bottom portion <NUM> can be pivotably coupled to blade central portion <NUM> by one or more pivots <NUM>, which are example can be hinges. Each of first and second side portions <NUM> can optionally be pivotable relative to blade central portion <NUM> from a first position in engagement with the respective sidewall <NUM> and a second position spaced away from the respective sidewall. Each of the first and second side portion <NUM> can be pivotably coupled to blade central portion <NUM> by one or more pivots <NUM>.

Bottom portion <NUM> can optionally be segmented, for example formed from a plurality of blade segments spaced apart along the length of the blade portion. For example, bottom portion <NUM> can be formed from a first blade segment and 756a, a second blade segment 756b, a third blade segment 756c, a fourth blade segment 756d and a fifth blade segment 756e sequentially spaced along the length of the blade portion <NUM>. The blade segments 756a-e are optionally pivotal with respect to each other relative to central portion <NUM> of the blade <NUM>. With respect to each adjacent set of blade segments, at least one of the adjacent blade segments can optionally include a side extension <NUM> that extends over the side of the other adjoining blade segment for inhibiting cargo within open bed <NUM> from passing between the blade segments. In this regard, for example third or central blade segment 756c can have a side extension <NUM> along each side thereof, one for overlapping the side of adjacent second blade segment 756b and the other for overlapping the side of fourth blade segment 756d. Similarly, second leg segment 756b can have a side extension <NUM> along its side adjacent first blade segment 756a for overlapping the first blade segment and fourth leg segment 756d can have a side extension <NUM> along its side adjacent fifth blade segment 756e for overlapping the fifth blade segment. Side extensions <NUM> result in the pivoting of one blade segment having a portion underlying a side extension of an adjacent blade segment causing the adjacent blade segment to pivot in unison with the one blade segment. For example, pivoting of second blade segment 756b results in third blade segment 756c pivoting in unison with the second blade segment. Pivoting of first blade segment 756a results in both second blade segment 756b and third blade segment 756c pivoting in unison with the first blade segment.

Each of the side portions <NUM> can optionally be segmented, for example formed from a plurality of blade segments spaced apart along the length of the side blade portion. For example, each side portion <NUM> can be formed from a first or upper blade segment 757a and a second or lower blade segment 757b below the first blade segment. The blade segments 757a-b are optionally pivotal with respect to each other relative to central portion <NUM> of the blade <NUM>. At least one of the first or second blade segments can optionally include a side extension <NUM> that extends over the side of the other blade segment for inhibiting cargo within open bed <NUM> from passing between the blade segments. For example, first blade segment 757a can have a side extension <NUM> along the side thereof adjacent second blade segment 757b for overlapping the side of second blade segment. The side extension <NUM> result in the pivoting of the second blade segment causing the first blade segment to pivot in unison with the second blade segment. First blade segment 757a can pivot independently of a second blade segment 757b.

Blade <NUM> can optionally rollably engage bottom wall <NUM> of the open bed <NUM>. In this regard, for example, the blade <NUM> can be carried by or secured to a carriage or rollable support <NUM>, for example to the front of the rollable support <NUM>. A plurality of rollers <NUM> can be provided on the bottom of the rollable support for engaging the bottom wall <NUM> so as to permit the support <NUM>, and blade <NUM> carried thereby, to roll forwardly and rearwardly along the length of the open bed <NUM>.

Dump mechanism <NUM> can optionally include a wiper <NUM>, which can be referred to as a bottom wiper, behind bottom portion <NUM> of the blade <NUM> for pushing any cargo that passes the blade portion <NUM> out of the open bed <NUM>. Wiper <NUM> can be formed from any suitable material such as hard rubber and can have an engaging edge 781a contoured to bottom wall <NUM> for enhancing the effectiveness of the wiper. Wiper <NUM> can be spaced behind blade bottom portion <NUM> by any suitable distance and secured to rollable sport <NUM> by any suitable means, for example one or more brackets <NUM>.

Dump mechanism <NUM> can optionally include a wiper <NUM>, which can be referred to as a side wiper, behind each side portion <NUM> of the blade <NUM> for pushing any cargo that passes the blade portion <NUM> out of the open bed <NUM>. Each wiper <NUM> can be formed from any suitable material such as hard rubber and can have an engaging edge 786a contoured to the respective side wall <NUM> for enhancing the effectiveness of the wiper. Each wiper <NUM> can be spaced behind the respective side bottom portion <NUM> by any suitable distance and secured to rollable sport <NUM> by any suitable means, for example one or more brackets <NUM>.

Blade <NUM> can optionally be slidably, rollable or otherwise movably disposed within open bed <NUM>, for example along sidewalls <NUM> and bottom wall <NUM>, from a first position away from rear opening <NUM> to a second position closer to the rear opening. The first position can include the position where blade <NUM> is fully retracted within open bed <NUM>, for example in a position adjacent front wall <NUM> as illustrated in <FIG>. The first position can also include a position where the blade <NUM> is between front wall <NUM> and rear opening <NUM>, as illustrated in <FIG> where the blade <NUM> is approximately halfway between front wall <NUM> and rear opening <NUM>. The second position can include a position where the blade <NUM> is fully extended within the open bed <NUM>, for example at rear opening <NUM> as illustrated in <FIG>. The second position can also include a position with the blade <NUM> is between front wall <NUM> and rear opening <NUM>, as illustrated in <FIG>.

Open bed <NUM> can include a guide member or mechanism <NUM> for guiding the blade <NUM> along the length of open bed <NUM> between its first and second positions, retaining blade bottom portion <NUM> and blade side portions <NUM> in respect of engagement with bottom wall <NUM> and side walls <NUM> during travel of the blade towards rear opening <NUM>, properly positioning the blade <NUM> within the open bed <NUM> as the blade travels between its first and second positions, inhibiting the blade <NUM> from lifting off bottom wall <NUM> as it pushes cargo out rear opening <NUM> or any combination of the foregoing. Guide mechanism <NUM> can include a guide rail <NUM> affixed to each side wall <NUM> and extending along the length of the sidewall. The guide rails <NUM> optionally oppose each other within open bed <NUM>. Each guide rail <NUM> can be made from any suitable material such as metal.

Rollable support <NUM> optionally includes a cooperating guide element <NUM> for engaging each guide rail <NUM> so as to retain the rollable support <NUM> in a desired position within open bed <NUM> as the blade <NUM> travels between its first and second positions. In this regard, for example, the rollable support <NUM> can include a roller <NUM> provided on each side thereof for rollably engaging the underside of the respective guide rail <NUM>. Each roller <NUM> can be mounted to the side of rollable support <NUM> by any suitable means such as a bracket <NUM>. Each bracket <NUM> can include any suitable adjustment assembly or mechanism <NUM> for properly positioning the respective roller <NUM> relative to the rollable support <NUM> and the respective guide mechanism <NUM>. Each adjustment mechanism <NUM> can optionally include one or more adjustment screws <NUM>.

Each of blade side portions <NUM> optionally includes a cutout <NUM> for accommodating or receiving the respective guide rail <NUM>. Each cutout <NUM> in a blade side portion <NUM> closely contours the shape of the respective guide rail <NUM> so as to inhibit cargo in the open bed <NUM> from passing the blade portion. Each side wiper <NUM> optionally includes a cutout <NUM> for accommodating or receiving the respective guide rail <NUM>. Each cutout <NUM> in a side wiper <NUM> closely contours the shape of the respective guide rail <NUM>, and optionally engages the guide rail, so as to inhibit cargo in the open bed <NUM> from passing the wiper <NUM>.

Front wall <NUM> of the open bed <NUM> optionally includes one or more holes are openings therein (not shown) for receiving the guide elements <NUM> carried by rollable sport <NUM> for permitting the dump mechanism <NUM> to closely engage or sit flush with the front wall <NUM> when the blade <NUM> is in its fully retracted position within the open bed.

Dump trailer <NUM> optionally includes an actuator <NUM> of any suitable type for longitudinally moving dump mechanism <NUM>, and blade <NUM> carried thereby, between their first and second positions within open bed <NUM>, including when blade <NUM> is pushing cargo within the open bed out rear opening <NUM> of the bed. The actuator <NUM> is secured to frame <NUM> by any suitable means, and optionally secured to forward extension <NUM> by any suitable means such as one or more brackets and fasteners. The actuator <NUM> can optionally include a telescoping piston <NUM> movable between a contracted position when blade <NUM> is in its first position and an extended position when the blade is in its second position. The piston <NUM> can be secured to dump mechanism <NUM>, for example the rear of rollable sport <NUM>, by any suitable means such as a bracket <NUM> provided on the rear of the rollable sport. When piston <NUM> is in a fully retracted position, for example as shown in <FIG>, the piston can be fully or substantially recessed within forward extension <NUM> of frame <NUM>. The actuator <NUM> can optionally include a suitable pneumatic assembly, for example a hydraulic assembly, for extending and retracting the piston <NUM>. Such a hydraulic assembly can optionally include a valve assembly <NUM> that can optionally be carried by the forward extension, as shown in <FIG>, or by the tractor unit <NUM> to which the dump trailer is attached. The hydraulic assembly can be powered by any suitable means, for example by a power take-off of the tractor unit <NUM> or otherwise by the tractor unit.

Actuator <NUM> can optionally be disposed within forward extension <NUM>, which as discussed above can be referred to as the gooseneck of dump trailer <NUM>. Actuator <NUM> can optionally be entirely disposed within the confines of the forward extension <NUM>. Actuator <NUM> can optionally be nested within the forward extension <NUM>. Actuator <NUM> can optionally not extend above the top of forward extension <NUM>. Actuator <NUM> can optionally not extend above the top of open bed <NUM>. Actuator <NUM> can optionally not extend above the top of dump trailer <NUM>. The disposition of actuator <NUM> within forward extension <NUM> facilitates the low-profile nature of dump trailer <NUM>. For example, the disposition of actuator <NUM> within forward extension <NUM> facilitates open bed <NUM> being disposed partially or entirely below the top of the forward extension. The disposition of actuator <NUM> within forward extension <NUM> permits blade <NUM> to travel a distance along the open bed <NUM> of at least about <NUM>% of the internal length of the bed <NUM>. The travel distance of the blade <NUM> can optionally exceed the length of the open bed <NUM> when actuator <NUM> is configured to move the blade <NUM> out over a fully extended tailgate in an open horizontal configuration.

Dump trailer <NUM> can optionally include one or more cover plates <NUM> removably joined to the top of forward extension <NUM> for protecting actuator <NUM> from cargo being loaded within open bed <NUM>. Front wall <NUM> of the open bed <NUM> is optionally provided with an opening <NUM> therethrough for permitting the piston <NUM> to extend through the wall <NUM>.

The dump trailer of the invention can optionally include an open bed that is pivotally coupled to the rear 706b of frame main portion <NUM> so that the front of the open bed can be pivoted from a first position in which the open bed is in a substantially horizontal position, for example parallel to frame main portion <NUM>, and a second position which the front of the open bed is inclined upwardly relative to rear 706b of the main frame portion <NUM>. Such a dump trailer can be used when the open bed is in its first position for loading and hauling of cargo, and used when the open bed is in its second position for discharging cargo from the open bed through a rear opening of the bed. Such discharging of cargo can occur by gravity, and can be enhanced by mechanical means if desired.

Dump trailer <NUM> can optionally include a tailgate <NUM> for removably covering rear opening <NUM> of the open bed <NUM>, for example during loading of the open bed with cargo and during travel of the dump trailer <NUM>. Tailgate <NUM> can be any suitable type and can optionally include a cover <NUM> having a size and shape approximating the size and shape of the rear opening <NUM>. Cover <NUM> can optionally be movable between a first position, for example a closed position as shown in <FIG>, in which the cover extends over and closes opening <NUM>, and a second position, for example an opened position as shown in <FIG>, in which the cover does not extend over or close opening <NUM>. The second position of cover <NUM> can optionally be above the opening <NUM> for facilitating the removal of cargo from the open bed during emptying of dump trailer <NUM>. Cover <NUM> can optionally extend in a horizontal position, for example above the opening <NUM>, when in its second position for facilitating the removal of cargo from the open bed <NUM>. Cover <NUM> can be movably or pivotally coupled to open bed <NUM> by any suitable means, for example first and second arms <NUM>. An actuator <NUM> can optionally be coupled to each of arms <NUM> for moving cover <NUM> between his first and second positions.

In operation and use, the dump trailer of the invention, for example dump trailer <NUM>, can be loaded with cargo, such as debris, for transporting the cargo from a first location to a second location. Open bed <NUM> of the dump trailer can be loaded by any suitable means, for example manually by workers or mechanically by any suitable construction loading equipment. The low-profile nature of dump trailer <NUM> facilitates the loading of open bed <NUM> by compact construction equipment. For example, such compact construction equipment may not have a sufficient reach for loading a conventional dump truck or trailer having a height greater than the top height of open bed <NUM>. The low-profile nature of dump trailer <NUM> further inhibits the construction loading equipment from undesirably engaging overhanging hazards such as trees and electrical lines during loading of the trailer. Tailgate <NUM> is optionally closed, for example in its first position, when open bed <NUM> is being loaded. During travel, the low-profile nature of dump trailer <NUM> can desirably inhibit the trailer from contacting overhanging structures, trees and electrical lines. Upon reaching the second location, tailgate <NUM> can be moved to its second or open position and dump mechanism <NUM> utilized to push the cargo being carried by the dump trailer out of open bed <NUM>, for example out rear opening <NUM>. In this regard, for example, blade <NUM> can be moved from a first position at the front of open bed <NUM> to a second position at the back opening of the open bed <NUM>. The retention of open bed <NUM> in a nonpivoted position during unloading desirably maintains a relatively low center of gravity for dump trailer <NUM> and tractor unit <NUM> so as to reduce tipping of the dump trailer during unloading.

All of the dimensions, ratios and number disclosed above can optionally pertain to dump trailer <NUM>.

In one aspect of the invention, a dump trailer for hauling and discharging cargo can be provided and can include a chassis support frame, an open-top bed coupled in substantially fixed relationship to the chassis support frame to prevent tilting of the open-top bed relative to the chassis support frame, the open-top bed having a tailgate opening at the rear of the open-top bed, a tailgate located at the rear of the open-top bed, the tailgate being selectively positionable between a closed configuration covering the tailgate opening and an open configuration away from the tailgate opening, a nose coupled to the chassis frame and extending forward of the bed, the nose supporting a hydraulic cylinder that is arranged for selective extension and retraction movement along a longitudinal path of travel extending forward and rearward along the bed, a blade coupled with the hydraulic cylinder for motion along the path of travel concomitant with the selective extension and retraction movement such that rearward extension of the hydraulic cylinder when cargo is in the bed pushes the cargo from the bed and through the tailgate opening, the nose having a trailer hitch connector, at least one wheel/axle assembly coupled to the chassis support frame for support thereof, the bed having right and left sidewalls running in parallel to the longitudinal path of travel, each of the opposed sidewalls having a guide rail running in parallel to the longitudinal path of travel, the blade having a right lateral edge facing the right sidewall and a left lateral edge facing the left sidewall, the left lateral edge defining a recess of complimentary dimensions for receipt of the guide rail on the left sidewall, the right lateral edge defining a recess of complimentary dimensions for receipt of the guide rail on the right sidewall, whereby the guide rails stabilize the blade along the path of travel.

The blade can have a bottom that is tilted rearwardly from the top. The blade can have a concave rearward facing surface. The trailer hitch connector can be a fifth wheel connector, and the trailer can be constructed and arranged to support at least <NUM> (<NUM>,<NUM> pounds) of cargo. The dump trailer open box can have a maximum height of about <NUM> (six feet).

In one aspect of the invention, a method of dumping can be provided and include coupling the dump trailer with a motive means, filling the trailer with cargo in a configuration where the blade resides at a forward position of the bed and the tailgate is in the closed configuration, operating the motive means with the push dump trailer attached to haul the cargo from a first location to a second location, opening the tailgate to place the tailgate in the open configuration and actuating the hydraulic cylinder to move the blade rearward with concomitant discharge of the cargo.

The dump trailer of the invention advances the art and overcome certain problems thereof by providing a low-profile dump trailer. The bed of the trailer optionally includes a discharge mechanism, for example utilizing a hydraulically actuated blade or ram to push cargo out of a rear opening of the bed. The bed optionally includes a rear tailgate at the rear opening. The blade can optionally be stabilized during movement down the bed by the use guide rails mounted on sidewalls of the bed. The dump trailer optionally includes a forward extending nose upon which an hydraulic cylinder may optionally be mounted, for moving the blade down the bed, so as not to occupy internal cargo space of the bed. The dump trailer can optionally be configured so that the bed tilts relative to a chassis frame supporting the bed for emptying cargo in the bed through a rear opening in the bed.

Claim 1:
A low profile dump trailer (<NUM>, <NUM>) for use with a tractor unit (<NUM>) having at least one rear wheel and axle assembly (<NUM>) with left and right wheels (<NUM>), comprising a goose neck (<NUM>, <NUM>) adapted for removable coupling to the tractor unit (<NUM>) and a dropped frame (<NUM>, <NUM>) joined to the goose neck (<NUM>, <NUM>) and extending rearwardly of the goose neck (<NUM>, <NUM>), the dropped frame (<NUM>, <NUM>) having a front and a rear and a top and a bottom, characterized in that the low profile dump trailer (<NUM>, <NUM>) further comprises an open box bed (<NUM>, <NUM>) joined to the top of the dropped frame (<NUM>, <NUM>) and extending at least partially below the goose neck for receiving cargo and having a front and having a rear opening (<NUM>, <NUM>) for permitting discharge of the cargo from the open bed (<NUM>, <NUM>), the open box bed (<NUM>, <NUM>) having a rectangular cross section or an open half cylinder with a semi-circular cross section and having a top height above ground of between <NUM>-<NUM> (five and six feet), and a plurality of trailer wheel and axle assemblies (<NUM>, <NUM>, <NUM>, <NUM>) joined to the bottom (<NUM>, <NUM>) of the rear (706b) of the dropped frame (<NUM>, <NUM>), each of the plurality of trailer wheel and axle assemblies (<NUM>, <NUM>, <NUM>, <NUM>) having left and right wheels (<NUM>, <NUM>) suitable for highway travel, each of the left and right wheels (<NUM>, <NUM>) of the plurality of trailer wheel and axle assemblies (<NUM>, <NUM>, <NUM>, <NUM>) being disposed entirely underneath the open bed (<NUM>, <NUM>).