Side tipping trailer, and door assembly

Abstract

A side tipping trailer body (11) and door (13) assembly, the door assembly (13) having on the inside thereof a support sheet (59) supported on the outside thereof by a frame assembly (61, 63, 75, 67, 69), to minimise flexure of the support sheet (59). The body (11) has a base (19), forward and rearward end walls (27) and (29), and a side wall (17) opposite an opening closed by the door (13). The door (13) pivots relative to the base (19) along a longitudinal axis extending proximal to a lower longitudinal extent of the door (13). The trailer body (11) and door (13) assembly has a resiliently bendable sheet (91) overlying and supported on the support sheet (59) and by at least a part of the base (19), and connecting to the base (19) along an axial extent spaced from the opening.

Description

[0001] “Side Tipping Trailer, and Door Assembly”

[0002] Field of the Invention

[0003] This invention relates to bulk solids material handling, and in particular to a vehicle for transporting bulk solids. This invention has particular application in bulk solids transporting vehicles that have a body that contains bulk solids, and is emptied by tipping the body about a pivot axis.

[0004] Background Art

[0005] The following discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.

[0006] Bulk solids transporting vehicles have long been used for transport of bulk solids such as rock and ore from mine sites. Typically, these vehicles often have rear or side tipping bodies for discharging of their loads. In applications on mine-sites, the vehicles can be quite large, having a payload 80 tonnes or more. Where the vehicle is to be used on the roads, the maximum payload is likely to be between 35 and 40 tonnes. Typically these vehicles are trailers, which are connected via a turntable or “fifth wheel” to a prime mover, and in road train applications, connected via a turntable or “fifth wheel” to dollies which are also hitched to like (or unlike) trailers.

[0007] Inroads have been made in reducing the weight of these trailers. This has been achieved through measures such as constructing the bodies of the trailers (the bowls) without a structural frame comprising longitudinal members and crossmembers (a ladder configuration), and constructing the body from resiliently deformable steel sheet material, which provides inherent structural rigidity without the need for framework supporting the steel sheet material. Examples of the applicant’s side tipping trailers are described in the patent specifications for Australian patents 2005220210 and 2012323778, the contents of which are incorporated herein by cross reference. These side tipping trailers have a door along the side of the body, with the door being hingedly mounted along the bottom of the body. The door is opened and closed via the action of hydraulic cylinders mounted to either end of the body of the trailer.

[0008] The body of the trailer is in turn hingedly mounted to the chassis of the trailer and may be tilted via the action of hydraulic cylinders mounted to either end of the body and the chassis, to raise the body so as to dispose the door side and the opening lowermost.

[0009] The action of the body being tilted and the door being open allows the material to discharge from the trailer quickly and away from the wheels of the trailer. This allows the operator to achieve drive through unloading without reversing. The door is hingedly connected to the body using a series of bushings, arranged axially in line, which are lubricated to ensure that the bushing can move without significant frictional effects.

[0010] An issue arising with these side tipping trailers arises from the repeated transport of fine particle payloads, in particular corrosive ore concentrates such as nickel and copper. The current hinge system joining the door to the body can fail prematurely when transporting these materials as they act as hang up points for the material which results in the deposition of material around the hinged area. This can lead to severe localised crevice and pitting corrosion in addition to abrasive wear around the hinge locations. Fine particle payloads also cause issues with the hinge greasing, as the deposited material around the hinge location can cause contamination within the grease as the tipper undergoes loading cycles. This will ultimately cause internal abrasive wear to the hinge assembly and lower the overall lifetime of the hinge.

[0011] A further issue arises with these side tipping trailers when operating with fine particle payloads in cold or wet climates. It has been found that moisture present in the payload may freeze or bind together when being transported. When the side tipping trailer attempts to discharge the payload in these circumstances, the payload having now bonded, which greatly increases the required angle of repose for the payload as the granules can no longer freely slide over the surface of one another. As the static coefficient of friction for the material is increased, the side tipping trailer cannot discharge the payload effectively resulting in a significant reduction in the operation efficiency of the trailers.

[0012] This issue is also prevalent to a lesser extent in climates with a high relative humidity (RH), as the increased ambient moisture in the environment causes the fine particles to adhere to one another, again increasing the required angle of repose for the material to undergo a successful discharge cycle. This is made more severe by the body and door of the side tipping trailer being fabricated out of steel, as the temperature differential between the ambient air and steel body causes condensation to deposit, which acts to further bind the payload together and prevent the side tipper from completing a clean discharge cycle.

[0013] Throughout the specification unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[0014] Disclosure of the Invention

[0015] It is an object of this invention to provide an alternative construction for the trailer body and the door, to provide additional weight savings, and preferably also to improve the sealing of those parts that mate when the door is closed.

[0016] In accordance with one aspect of the invention there is provided a side tipping trailer body and door assembly, the door assembly having on the inside thereof a support sheet supported on the outside thereof by a frame assembly to minimise flexure of said support sheet, the body having a base, forward and rearward end walls, and a side wall opposite an opening closed by said door, said door pivoting relative to said base along a longitudinal axis extending proximal to a lower longitudinal extent of said door; and said trailer body and door assembly having a resiliently bendable sheet overlying and supported on said support sheet and at least a part of said base, and connecting to said base along an axial extent spaced from said opening.

[0017] Preferably the upper edges of said end walls along said opening are joined by a longitudinally extending brace bar to obviate flexing of said end walls. While other bracing may also be effective to prevent such flexing, the brace bar is considered to be simple and effective.

[0018] Preferably said resiliently bendable sheet forms a pivotal mount for said door connecting to said body.

[0019] Preferably said door is suspended from each of said end walls by a pair of double acting rams, one attached to each end wall. The double acting rams are in use actuated to open and close the door.

[0020] Preferably said resiliently bendable sheet connecting with said support sheet extends entirely along said support sheet to provide a wear surface as load is discharged from said trailer.

[0021] Preferably said resiliently bendable sheet connecting with said support sheet is mounted to said support sheet by a plurality of plate-like protrusions bonded to said resiliently bendable sheet, each of said plate-like protrusions extending in and supported in a complementary shaped aperture in said support sheet. Collectively, the arrangement of plate-like protrusions extending through complementary shaped apertures registers the position of the frame assembly and support sheet, relative to the resiliently bendable sheet.

[0022] Preferably said axial extent spaced from said opening is located no closer than one fifth of the distance from said opening toward a centre-line of said trailer body.

[0023] Preferably said line spaced from said opening is located between one fifth of the distance from said opening toward the centre-line of said trailer body and the centreline of said trailer body.

[0024] In the manner of the above two described arrangements, the resiliently bendable sheet may bend about a radius which is not too sharp, when the door is closed. The plate-like protrusions bonded to the resiliently bendable sheet being received in the complementary shaped apertures in the support sheet of the door, register the position of the door relative to the body, and the resi liently bendable sheet forms a hinge, bending about the radius at the intersection of door and body. The resi liently bendable sheet being resil iently bendable, is biased to a flat position, so will always urge against the support sheet. The plate-like protrusions bonded to the resiliently bendable sheet being received in the complementary shaped apertures in the support sheet of the door prevent the resiliently bendable sheet from sliding upward relative to the support sheet.

[0025] In an alternative embodiment, said line may be located away from the centre line and away from the opening including toward and possibly at the top of said side wall, but this would be less preferred due to the additional resiliently bendable sheeting required. It is not necessary that the resiliently bendable sheet lines the entire body and door, and in practice, it is sufficient if the line at which the plastic sheet is attached to the body is located somewhere between the centreline of the trailer body and toward the opening, but not so close that the resiliently bendable sheet is bent too sharply when the door is closed.

[0026] Preferably said resiliently bendable sheet is clamped to said base by a plurality of fasteners extending along said axial extent. The fasteners may be staggered relative to the axial extent of the body to provide additional strength to the connection between the resiliently bendable sheet and the base.

[0027] Preferably the fasteners comprise locking nuts and bolts, and most preferably pin and collar fasteners. These may be of the type known by their proprietary name “Huck bolts”, produced by Huck Mfg. Co..

[0028] Preferably the bolts each have a dome head or button head configuration, with the heads being located inside the trailer body.

[0029] Preferably said base and said side wall comprises a formed sheet with the base extending partially over said resiliently bendable sheet.

[0030] Preferably, a further sheet extends under said resiliently bendable sheet and toward said door, said base and said further sheet being formed with coincident apertures for said plurality of fasteners to clamp said resiliently bendable sheet therebetween. Preferably said door has inwardly extending guide wings at each end thereof which extend substantially parallel and next to said forward and rearward end walls, said guide wings each having an upper arcuate edge co-operating with a forward guide pin attached to said forward end wall and a rearward guide pin attached to said rearward end wall, to guide said door as it is opened and closed.

[0031] Preferably said guide wings are located disposed inside said body.

[0032] Preferably said upper arcuate edges each include a stop portion to engage said guide pins to limit the opening extent of said door. This prevents the door opening and the resiliently bendable sheet bending beyond a position further than is required. Typically the door would open to the extent that the support sheet and the base of the body extend in the same plane.

[0033] Preferably the guide wings each have a lower edge opposed to said upper arcuate edge with a lower arcuate portion arranged to co-operate with the resiliently bendable sheet in a manner that the curvature of the resiliently bendable sheet conforms to the shape of the lower arcuate edge as the door is moved from an open position toward a closed position. The lower edge is opposed to the upper arcuate edge in the sense that it is on the other side of the guide wing from the upper arcuate edge. The ends of the lower edge and the upper arcuate edge are adjacent in the sense that they meet each other on account of the arcuate form of the upper arcuate edge and the lower arcuate portion of the lower edge.

[0034] Preferably said guide wings include at least one tooth extending from said lower edge arranged to be received in a slot formed in the edge of said resiliently bendable sheet, to register said resiliently bendable sheet relative to said guide wings.

[0035] Preferably said resiliently bendable sheet is a resiliently bendable plastic sheet.

[0036] Preferably said resiliently bendable plastic sheet is selected from one of ultra-high molecular weight polyethylene, polydicyclopentadiene, and composite fibre reinforced polymers in general. The fibres used in fibre reinforced polymers can be glass, carbon, or basalt.

[0037] Alternatively said resiliently bendable sheet is a resiliently bendable metal sheet formed from a steel alloy, such as is used for spring steel. Preferably in said closed position, said door extends between inner edges of said forward end wall and said rearward end wall.

[0038] Preferably each said end wall is of single sheet construction, and includes reinforcing coaming of single sheet construction along the top thereof, said reinforcing coaming having a bracket fillet welded along a lower edge to said end wall, said end wall and coaming having a mount for a hydraulic ram fixed thereto, said mount comprising at least one plate member extending through slots in said end wall and in said coaming, and into a ram fixing bracket for attaching one end of said hydraulic ram, said at least one plate member being welded in position in said slots. The other end of the ram is attached to the door. Forward and rearward rams operate in unison to open and close the door, which is hingedly attached to the body.

[0039] The plate member or plate members serve a two-fold purpose. First, during assembly of the end wall and coaming, the plate members provide registration of these parts so that their relative positions are correctly set, before welding commences. Secondly, since the ram mount is essentially secured to sheet metal, the plate member or plate members reinforce the ram mount against flexing.

[0040] The side tipping trailer body and door assembly is intended for use in an arrangement on a chassis as described in the applicant’s Australian patent 2005220210, although could equally easily be used on other chassis, such as those incorporating rubber mounting surfaces extending between the base of the body and the chassis.

[0041] The forward and rearward end walls and reinforcing panels are preferably formed of a resil iently deformable sheet material.

[0042] The end wall coaming is preferably formed of a resi I iently deformable sheet material.

[0043] The end wall and end wall coaming is preferably topped with a cover flange Preferably said sides of said body are also formed of resiliently deformable sheet material. Reinforcing can also be provided through external flanges at the end, and coaming along longitudinal edges to prevent outward flexing of the walls.

[0044] Preferably the fixed side walls and base are fully welded, to form a rigid structure single sheet structure, lapped at the join between side wall and base. Further reinforcing can be provided by welding a web at the intersection between at least forward and rearward walls and the fixed side wall and base.

[0045] Preferably said resiliently deformable sheet material comprises sheet having at least 370 Brinell hardness. The sheet material may be quench tempered plate, wear grade steel, high impact steel or high tensile steel. In practice sheet having Brinell hardness of 400, 450, 500, 550, or 600 may be employed. A yield strength of from 1000 to 1800 Mpa, is preferred, with 1200 to 1500 Mpa being most suitable.

[0046] Brief Description of the Drawings

[0047] Three preferred embodiments of the invention will now be described in the following description of a side tipping trailer body for transporting bulk solids, made with reference to the drawings in which:

[0048] Figure 1 is a side view of the side tipping trailer body, viewed from the door side thereof, according to the first embodiment of the invention;

[0049] Figure 2 is a front end view of the side tipping trailer body according to either embodiment;

[0050] Figure 3 is an isometric view from above, of the side tipping trailer body of the first embodiment, with the door shown in the closed position;

[0051] Figure 4 is an isometric view from above, of the side tipping trailer body of the first embodiment, with the door shown in the open position;

[0052] Figure 5 is top plan view of the side tipping trailer body of the first embodiment, with the door shown in the closed position;

[0053] Figure 6 is top plan view of the side tipping trailer body of the first embodiment, with the door shown in the open position;

[0054] Figure 7 is a cross-section view through section A-A in figure 5 also showing the inside the rear end wall of the side tipping trailer body; Figure 8 is a cross-section view through section B-B in figure 6 also showing the inside the rear end wall of the side tipping trailer body;

[0055] Figure 9 is a front end view of the side tipping trailer body according to either embodiment, showing the door in the closed position, and showing in dashed outline, the door in the open position;

[0056] Figure 10 is an isometric view of detail of the door frame and support sheet for the door in the side tipping trailer;

[0057] Figure 11 is view of the top edge of the door frame and support sheet of figure 10;

[0058] Figure 12 side view of detail of the door frame and support sheet of figures 10 and 11 ;

[0059] Figure 13 is a rear isometric end view of the fabricated plastic sheet used in the side tipping trailer body of the first embodiment, shown in the position adopted when the door is closed;

[0060] Figure 14 is an isometric view of the fabricated plastic sheet of figure 13, shown in the position adopted when the door is closed;

[0061] Figure 15 is an outside plan view of fabricated plastic sheet of figures 13 and 14, shown in the position adopted when the door is closed;

[0062] Figure 16 is a plan view of a guide wing used in the side tipping trailer;

[0063] Figure 17 is an isometric view of the guide wing of figure 16;

[0064] Figure 18 is an edge view of the guide wing of figures 16 and 17; and

[0065] Figure 19 is a cross section view through part of the door near the rear of the trailer of the first embodiment, and showing elements of the trailer at the rear of the trailer;

[0066] Figure 20 is an isometric view of Detail B in figure 4;

[0067] Figure 21 is a cross-section view across part of the base of the side tipping trailer of the first embodiment, showing detail of the attachment of the plastic sheet to the base;

[0068] Figure 22 is an isometric view from above, of the side tipping trailer body of the second embodiment, with the door shown in the open position;

[0069] Figure 23 is a cross-section view through section A-A in figure 5 also showing the inside the rear end wall of the side tipping trailer body, but according to the second embodiment; Figure 24 is a cross-section view across part of the base of the side tipping trailer of the second embodiment, showing detail of the attachment of the plastic sheet to the base;

[0070] Figure 25 is a side view of the side tipping trailer body, viewed from the door side thereof, according to the third embodiment of the invention; and

[0071] Figure 26 is a close-up side view of detail of part of figure 25.

[0072] Best Mode(s) for Carrying Out the Invention

[0073] The embodiments shown in the figures are a side tipping body 10 for a side tipping trailer. Referring to figure 3, the side tipping body 10 features an open-topped body 11 and side opening door 13. In use the side tipping body is intended to be mounted to a chassis (not shown) for use when attached to a prime mover or dolly, to transport bulk material, both on-road and off-road at mine sites.

[0074] The open topped body 11 has a unitary side 17 and base 19 construction, formed of three portions of sheet 21 , 22, and 23 fillet welded about axially extending lines 25 and 26, due to stock sheet width limitations. The sheet portions 22 and 23 are formed with a curvature as illustrated.

[0075] A forward end wall 27 and rearward end wall 29 are fillet welded to the side 17 and base 19 to form an enclosure for containing bulk solids for transport. The rearward end wall 29 is a mirror image of the forward end wall 27.

[0076] As can be seen in figures 3 to 8 illustrating the first embodiment, (and 22 and 23 in the second embodiment), webbing 33 is fillet welded to the forward end wall 27 and the rearward end wall 29, between these parts and the sheets 21 , 22, and 23 forming the side 17 and base 19, attached by fillet welding. Reinforcement against flexing of the side 17 is provided by coaming 35 extending along the inside upper surface of the side 17. Further structural rigidity is provided in the upper extents of the forward end wall 27 and the rearward end wall 29 by coaming 37 topped with convex curved flanges 39, and u-channel bracket 41 secured also by fillet welding at the upper corner between side 17 and the forward wall 27, and between side 17 and the rearward wall 29. The coaming 37 has an obliquely outwardly extending portion 37a (obliquely outwardly extending relative to the end wall 27) topped with a parallel extending portion 37b (extending parallel relative to the end wall 27), which is in turn topped by the convex curved flange 39. As stated above, the forward end wall 27 and rearward end wall 29 are mirror images of each other, so the construction at each end is identical.

[0077] Structural coaming 45 is provided along the underside of the base 19 at the edge of the opening which is closed by the door 13. The structural coaming 45 extends from the forward end wall 27 and rearward end wall 29, secured thereto by forward and rearward flanges 47 and 49. The forward and rearward flanges 47 and 49 and the structural coaming 45 support three bushings 51 which pivotally mount the body 11 to the edge of the trailer chassis (not shown) for tipping. The u-channel bracket 41 covers a mounting point 53 provided on each of the forward end wall 27 and rearward end wall 29 to mount an end of a double acting hydraulic ram, the other end of which is secured to the trailer chassis, to tip the body 11 about the bushings 51 . A bracket 54 is provided on each of the forward end wall 27 and rearward end wall 29 to mount supports for hydraulic lines for hydraulic rams.

[0078] At the top comers of the forward end wall 27 and rearward end wall 29, a brace bar 55 is mounted, extending longitudinally along and above the opening in the body 11 . The brace bar 55 secures the forward end wall 27 and rearward end wall 29 against outward flexing which would allow spillage of fine particulate matter from the side tipping body 10 when the door 13 is closed. A segmented-curved support 57 extends transversely from the brace bar 55 to the top of the side 17 of the body 11 , mid-way along the length of the body 10. This support 57, together with the convex curved flanges 39 provide a surface to support a tarpaulin (not shown) to cover the load, as is customary when a particulate load is being transported.

[0079] The materials used in the body of the trailer are quenched and tempered high strength steels. These steels are manufactured by Svenskt Stal AB (SSAB) and have been chosen for their high mechanical strength and fatigue resistance, which ultimately aids in extending the lifetime of the trailers. The expected operational lifetime of the trailer is approximately 31200 cycles over a period of 10 years. Hardox 450TMis used predominately in the body on surfaces where there is expected contact with the transporting payload, due to the high hardness of the material, meaning that the material will be able to resist localised plastic deformation when loading and unloading. The thickness of Hardox 450 within the body varies between 4 mm and 10 mm.

[0080] Strenx 700TMis used for the structural components of the body, as well as in the trailer chassis due to the high mechanical strength of the steel making it the optimal choice for load bearing capabilities. The thickness of this material ranges from a nominal thickness of 4mm to a maximum thickness of 16 mm along the structural elements of the body and chassis.

[0081] The enclosure 31 is completed by the outwardly opening door 13. In the closed position, the door 13 extends between inner edges of the forward end wall 27 and the rearward end wall 29. The door 13 is fabricated from a support sheet 59 formed from 4 mm quenched and tempered high strength steel sheet which extends across the entire inner surface of the door, and is supported on an upper longitudinal coaming 61 and a lower longitudinal coaming 63, bridged by a forward transverse rib 65 at the forward end of the body and a rearward transverse rib 67 at the rearward end of the body, and bridged by two spaced transverse ribs 69 located spaced from the forward transverse rib 65 and the rearward transverse rib 67. The support sheet 59 is formed of Hardox 450 ™, and the upper longitudinal coaming 61 , lower longitudinal coaming 63, and transverse ribs 65, 67, and 69 are fabricated from Strenx 700TMin pieces fabricated to form a channel structure and fillet welded, and fillet welded to the support sheet 59. The support sheet 59 has five rectangular apertures 71 formed therethrough, three such apertures located spaced evenly along an upper extent of the support sheet 59 and two such apertures located along a lower extent of the support sheet 59, below the forward and rearward upper apertures.

[0082] The forward transverse rib 65 and rearward transverse rib 67 each have a ram mount lever 73 pivotally attached thereto which is in turn pivotally attached to one end 75 of a double acting hydraulic ram 77, the other end of the double acting hydraulic ram 77 being pivotally attached to a ram mount 79 welded onto the coaming 37 and the forward end wall 27 and the rearward end wall 29 at respective ends of the body 11 . The ram mount levers 73 are pivotally attached to the forward transverse rib 65 and rearward transverse rib 67 at a position slightly above the halfway point of the height of the forward transverse rib 65 and rearward transverse rib 67 from the lower longitudinal coaming 63 to the upper longitudinal coaming 61 . In this manner, the door 13 is balanced on the end of the hydraulic rams 77, as will be understood from further description which follows. The hydraulic rams 77 are in use actuated to open and close the door 13.

[0083] Referring to figures 4, 7, 8, and 16 to 20, the door 13 has inwardly extending guide wings 81 , one mounted to the bottom of each of the forward transverse rib 65 and rearward transverse rib 67 at each end of the door 13. The guide wing 81 illustrated in figures 16 to 18 is that which is attached to the rearward transverse rib 67. The guide wing 81 which attaches to the forward transverse rib 65 is a mirror image of that illustrated in figures 16 to 18. The guide wings 81 extend substantially parallel, inside and next to the forward and rearward end walls 27 and 29. The guide wings 81 each having an upper arcuate edge 83 having a constant radius about a locus which prescribes the axis about which the door 13 rotates when opened and closed by the hydraulic rams 77. The upper arcuate edge 83 of each guide wing 81 cooperates with a forward guide pin 85 attached to the forward end wall 27 and a rearward guide pin 87 attached to the rearward end wall 29 respectively, to guide said door as it is opened and closed.

[0084] The upper arcuate edges 83 each include a stop portion formed by a catch 89 to engage said guide pins 85, 87 to limit the opening extent of the door 13. This prevents the door opening and the plastic sheet bending beyond a position further than is required. Typically the door would open to the extent that the support sheet 59 and the base 19 of the body 11 extend in the same plane.

[0085] The trailer body 11 and door 13 have a resiliently bendable sheet 91 formed of 8 mm thick ultra high molecular weight polyethylene (UHMWPE) plastic sheet overlying and supported on the support sheet 59 and extending to and across underneath a part of the sheet 23 of the base 19, and connecting to the base 19 along an axial extent spaced from said opening. At this junction, the sheet 23 and a further sheet 93 of 3 mm mild steel further comprising the base 19 sandwich the UHMWPE sheet 91.

[0086] The UHMWPE sheet 91 is shown in the folded position which it is urged to when the door 13 is closed, in figures 13 to 15. On the outside of the UHMWPE sheet 91 where it contacts the support sheet 59 of the door are plate-like protrusions in the form of five rectangular pads 95 which are sized and aligned to be received in and to cooperate with the rectangular apertures 71 in the support sheet 59 of the door 13, registering the UHMWPE sheet 91 relative to the support sheet 59 of the door 13. The rectangular pads 95 are also formed of UHMWPE and are welded to the UHMWPE sheet 91 . As the UHMWPE sheet 91 is resi I iently biased to a flat position, the rectangular pads 95 will be retained in cooperation with the rectangular apertures 71 .

[0087] Referring again to figures 16 to 18, the guide wings 81 each have a lower edge 97 arranged having an arcuate corner 99 to co-operate with the UHMWPE sheet 91 in a manner that the curvature of the UHMWPE sheet 91 conforms to the shape of the arcuate corner 99 as the door 13 is moved from an open position toward a closed position.

[0088] The guide wings 81 each include at least one tooth in the form of two tabs 101 and 103 extending from said lower edge 97 by which the guide wings 81 are welded to the door support sheet 59 and forward transverse rib 65 and the rearward transverse rib 67 of the door 13 at each end of the door 13. The two tabs 101 and 103 are received in slots 105, 107 respectively formed in the edge 109 of the UHMWPE sheet 91 , to register the UHMWPE sheet 91 relative to the guide wings 81.

[0089] The guide wings 81 each are formed of three layers of laminated welded Strenx 700 ™ to provide greater thickness in locations considered to be under greater stress during unloading operations, hence the provision of the thickened ends proximal to where the guide wings are attached to the door sheet panel 59 and proximal to the hook 89.

[0090] As discussed above, the UHMWPE sheet 91 is disposed overlying and supported on the support sheet 59 registered with the apertures 71 in the support sheet 59 and with the tabs 101 and 103 in the guide wings 81 . The UHMWPE sheet 91 and extends across the mild steel sheet 93 which underlies the entire base 19 of the body 11 , and extends to lie underneath a part of the sheet 23 of the base 19. The UHMWPE sheet 91 is clamped to sheet 23 and mild steel sheet 93 a plurality of fasteners 111 extending along the axial extent of the body 11 at the intersection of these parts. The axial extent in this first embodiment is located close to the centre line of the body, within 10 percent of the width of the body, but closer to the door opening. The fasteners 111 are staggered relative to the axial extent of the body 11 to provide additional strength to the connection between the UHMWPE sheet 91 and the base 19, to reduce the risk of fracturing the UHMWPE sheet 91 along a single line. The fasteners extend through pre-formed apertures in the sheets 23 and 93.

[0091] The fasteners include bolts 113 each having a button head 115 configuration, with the heads 115 being located inside the trailer body 11 to minimise hang up of particulate matter, and locking nuts 117 underneath the body 11 against the sheet 93. The best fasteners 11 1 for this application are pin and collar fasteners, of the type known by their proprietary name “Huck bolts”, produced by Huck Mfg. Co..

[0092] In the manner described, the UHMWPE sheet 91 forms a pivotal mount for the door 13 connecting to the body 11. The pivoting is controlled by a combination of the resilient nature of the UHMWPE sheet 91 , the registration of the UHMWPE sheet 91 with the fasteners 111 , the apertures 71 in the door, and the tabs 101 and 103 in the lower edge 97 of the guide wings 81 , and the balancing of the door on the ram mount levers 73 securing to the rams 77.

[0093] The UHMWPE sheet 91 extends entirely along the support sheet 59 to provide a wear surface as load is discharged from said trailer 10.

[0094] In the manner of the above described arrangement, the UHMWPE sheet 91 may bend about a radius which is not too sharp, when the door 13 is closed. The platelike protrusions 95 bonded to the plastic sheet 91 being received in the complementary shaped apertures 71 in the support sheet 59 of the door 13, register the position of the door 13 relative to the body 11 , and the UHMWPE sheet 91 forms a hinge, bending about the radius of the arcuate corner 99 of the guide wings 81 at the intersection of door 13 and body 11 . The UHMWPE sheet 91 being resiliently bendable, is biased to a flat position, so will always urge against the support sheet 59. The plate-like protrusions 95 bonded to the plastic sheet being received in the complementary shaped apertures 71 in the support sheet 59 of the door prevent the UHMWPE sheet 91 from sliding upward relative to the support sheet 59.

[0095] The second embodiment is illustrated in figures 22 to 24, and is differs from the first embodiment to a number of respects. First, the axial extent along which the fasteners 111 are located, is positioned in a line located away from the centre line of the body 11 and much closer to the opening in the body 11 , and to the door 13. As can be seen in figure 23 the axial extent along which the fasteners 111 are located, is positioned along the lower edge 97 of the guide wing proximal to the hook 89 (viewed when the door 13 is closed), away from the arcuate corner 99, so that flexure does not take place about the fasteners 111 when the door 13 is opened and closed. As a consequence a further sheet 119 of Hardox 450TMis fillet welded to sheet 23 in the base 19, to extend the steel floor closer to the door. This arrangement means that the mild steel sheet 93 in the base 19 may be omitted, with the sheet 119 of Hardox 450TMbeing located over the top the UHMWPE sheet 91 , and secured directly with fasteners 111 as described in the first embodiment.

[0096] Both embodiments provide advantages over the arrangements described in previous patent applications made by the applicant. One particular advantage is use of ultra-high molecular eight polyethylene within the tipper body without compromising the mechanical and wear properties of the tipper. This provides a reduction of approximately 600 kilograms over the current model of tipper, resulting in a total estimated tare weight of 2631 kg for the combined chassis and tipper body. Achieving a reduction of the tare weight provides a significant advantage, as prospective clients will be able to carry larger payloads while still complying with National Heavy Vehicle Standards. This increases the operational efficiency of the trailers as well as reducing the lifetime Carbon emissions of the unloaded tipper and a loaded tipper carrying the same volume load as prior art tippers of the applicant, as a result of decreased fuel consumption. Additionally, the use of ultra-high molecular eight polyethylene within the tipper body has allowed for the inclusion of a flexural hinge. This hinge eliminates the need for the current lubricated bushings, which undergo severe abrasive wear and corrosive cracking when transporting granulated materials. This ultimately results in an increased estimated lifetime for the tipper.

[0097] The supplier for UHMWPE sheet used in the prototype was German plastics manufacturer Rochling, and UV stabilised Polystone® was chosen as it offered an extended lifetime in outdoor locations in comparison with the other products. The density of this plastic is significantly lower than steel at 0.93 gjcm3whilst still having a relatively high tensile yield strength of 20.67 MPa. This lack of strength within this material in comparison to the current Hardox 450TMsteel is offset by increasing the thickness of the plastic in the areas where it is applied, compared with the thickness of the steel, resulting in an overall net loss of weight while maintaining functionality.

[0098] The flexible nature of the plastic has also provided some disadvantages for the design, as large deflections and stresses can be experienced when loaded. Thus, to provide additional stiffness to the design, steel support in the form of the frame for the door 61 , 63, 65, 67, and 69, and the under base coaming 45 have been used to support the front and bottom sections of the plastic sheet 91 to ensure the composite is rigid and able to resist the effects of significant deformation. However, the hinged area does not have any steel supports, allowing this allow it to bend unrestricted around the curvature 99 shape of the guide wing 81 .

[0099] The third embodiment of the invention introduces a structural hinge for the door 13, formed by a clevis assembly having a rotational axis disposed along a longitudinal axis extending proximal to a lower longitudinal extent of said door. In all embodiments the door 13 pivots about this longitudinal axis, but in the first two embodiments the pivoting about the rotational axis is prescribed by the combination of the resilient nature of the UHMWPE sheet 91 , the registration of the UHMWPE sheet 91 with the fasteners 111 , the apertures 71 in the door, and the tabs 101 and 103 in the lower edge 97 of the guide wings 81 , and the balancing of the door on the ram mount levers 73 securing to the rams 77, which is as described above. In the third embodiment the pivoting about the rotational axis is restricted by the structural hinge, which provides greater strength than the arrangements of the first and second embodiments alone. The UHMWPE sheet 91 being located above the structural hinge, protects the pin and bush assembly from the abrasive effect of loose abrasive material carried as load in the trailer body. The third embodiment is the same as the second embodiment in all respects other than the arrangements discussed here.

[0100] The outwardly opening door 13 is fabricated from a support sheet 59 formed from 4 mm quenched and tempered high strength steel sheet which extends across the entire inner surface of the door, and is supported on an upper longitudinal coaming 61 and a lower longitudinal coaming 63, bridged by a forward transverse rib 65 at the forward end of the body, a rearward transverse rib 67 at the rearward end of the body, and a central transverse rib 121 located equidistant between the transverse ribs 65 and 67. The upper longitudinal coaming 61 and lower longitudinal coaming 63 is also bridged by two spaced transverse ribs 69 located spaced between the forward transverse rib 65 and central transverse rib 121 and the rearward transverse rib 67. The support sheet 59 is formed of Hardox 450TM, and the upper longitudinal coaming 61 , lower longitudinal coaming 63, and transverse ribs 65, 67, and 69 are fabricated from Strenx 700TMin pieces fabricated to form a channel structure and fillet welded, and fillet welded to the support sheet 59.

[0101] The forward transverse rib 65, rearward transverse rib 67, and central transverse rib 121 each have an arm portion 123 extending down below the lower longitudinal coaming 63, with fingers 125, 127 with apertures to receive a pin 129 in a clevistype arrangement, the pin 129 being received through the bushings 51 which also pivotally mount the body 11 to the edge of the trailer chassis (not shown) for tipping.

[0102] To align the forward transverse rib 65 at the forward end of the body, and rearward transverse rib 67 at the rearward end of the body with the bushings 51 , the bushings at the forward and rearward ends of the body 11 are moved into alignment with the forward transverse rib 65 and rearward transverse rib 67, compared with the first embodiment, In addition, the rectangular apertures 71 in the support sheet 59 of the door 13, registering the UHMWPE sheet 91 relative to the support sheet 59 of the door 13, and the rectangular pads 95 welded to the UHMWPE sheet 91 , are not required, since registration of the sheet 91 with the door 13 is not as critical as in the first and second embodiments in order to control the poise of the door when opening and closing.

[0103] It should be appreciated that the scope of the invention is not limited to the particular embodiments disclosed herein.

Claims

The Claims Defining the Invention are as follows1. A side tipping trailer body and door assembly, the door assembly having on the inside thereof a support sheet supported on the outside thereof by a frame assembly to minimise flexure of said support sheet, the body having a base, forward and rearward end walls, and a side wall opposite an opening closed by said door, said door pivoting relative to said base along a longitudinal axis extending proximal to a lower longitudinal extent of said door; and said trailer body and door assembly having a resiliently bendable sheet overlying and supported on said support sheet and by at least a part of said base, and connecting to said base along an axial extent spaced from said opening.

2. A side tipping trailer body and door assembly as claimed in claim 1 , wherein the upper edges of said end walls along said opening are joined by a brace bar to obviate flexing of said end walls.

3. A side tipping trailer body and door assembly as claimed in claim 1 or 2, wherein said resiliently bendable sheet forms a pivotal mount for said door connecting to said body.

4. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein said door is suspended from each of said end walls by a pair of double acting rams, one attached to each end wall.

5. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein said resiliently bendable sheet connecting with said support sheet extends entirely along said support sheet to provide a wear surface as load is discharged from said trailer.

6. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein said resiliently bendable sheet connecting with said support sheet is mounted to said support sheet by a plurality of plate-like protrusions bonded to said resiliently bendable sheet, each of said plate-like protrusions extending in and supported in a complementary shaped aperture in said support sheet.

7. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein said axial extent spaced from said opening is located no closer than one fifth of the distance from said opening toward a centre-line of said trailer body.

8. A side tipping trailer body and door assembly as claimed in claim 7, wherein said line spaced from said opening is located between one fifth of the distance from said opening toward the centre-line of said trailer body and the centreline of said trailer body.

9. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein said resiliently bendable sheet is clamped to said base by a plurality of fasteners extending along said axial extent.

10. A side tipping trailer body and door assembly as claimed in claim 9, wherein the fasteners are staggered relative to the axial extent of the body to provide additional strength to the connection between the resiliently bendable sheet and the base.

11. A side tipping trailer body and door assembly as claimed in claim 9 or 10, wherein the fasteners comprise locking nuts and bolts, and most preferably pin and collar fasteners.

12. A side tipping trailer body and door assembly as claimed in claim 11 , wherein the bolts each have a dome head or button head configuration, with the heads being located inside the trailer body.

13. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein said base and said side wall comprises a formed sheet with the base extending partially over said resiliently bendable sheet.

14. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein a further sheet extends under said resiliently bendable sheet and toward said door, said base and said further sheet being formed with coincident apertures for said plurality of fasteners to clamp said resiliently bendable sheet therebetween.

15. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein said door has inwardly extending guide wings at each end thereof which extend substantially parallel and next to said forward and rearward end walls, said guide wings each having an upper arcuate edge co-operating with a forward guide pin attached to said forward end wall and a rearward guide pin attached to said rearward end wall, to guide said door as it is opened and closed.

16. A side tipping trailer body and door assembly as claimed in claim 15, wherein said guide wings are located disposed inside said body.

17. A side tipping trailer body and door assembly as claimed in claim 15 or 16, wherein said upper arcuate edges each include a stop portion to engage said guide pins to limit the opening extent of said door.

18. A side tipping trailer body and door assembly as claimed in any one of claims 15 to 17, wherein the guide wings each have a lower edge opposite to said upper arcuate edge with a lower arcuate portion arranged to co-operate with the resiliently bendable sheet in a manner that the curvature of the resiliently bendable sheet conforms to the shape of the lower arcuate portion as the door is moved from an open position toward a closed position.

19. A side tipping trailer body and door assembly as claimed in claim 18, wherein said guide wings include at least one tooth extending from said lower edge arranged to be received in a slot formed in the edge of said resiliently bendable sheet, to register said resiliently bendable sheet relative to said guide wings.

20. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein in said closed position, said door extends between inner edges of said forward end wall and said rearward end wall.

21. A side tipping trailer body and door assembly as claimed in any one of the preceding claims, wherein each said end wall is of single sheet construction, and includes reinforcing coaming of single sheet construction along the top thereof, said reinforcing coaming having a bracket fillet welded along a lower edge to said end wall, said end wall and coaming having a mount for a hydraulic ram fixed thereto, said mount comprising at least one plate memberextending through slots in said end wall and in said coaming, and into a ram fixing bracket for attaching one end of said hydraulic ram, said at least one plate member being welded in position in said slots.

Images