AU2014227433A1 - Truck Tipping Bodies - Google Patents

Abstract

Abstract A method of forming a ram connection between a tipping body and a tipping ram for trucks and particularly for rear dump trucks, by providing a load bearing pad capable of being pushed against the underside of the relatively smooth floor of the tipping body by the tipping ram so as to tilt the tipping body about its transverse tipping axis; forming a ram connection on the underside of the load bearing pad which provides the connection between the tipping ram and the tipping body, but the system is resistant to premature fatigue cracking causing increased maintenance costs and/or reduced life. 1'~ 'i'' / ~'N4~ 1 ~ '\A N ' '1 >"t I "V <K I' N -K N \ ~ N "N, ''tN ~r t "-< / V N 'N A~k~.~-A~ '~-ft"~. -- \ I(VN~AA~L. ~sf~ N ~sAy N" ~ ~~~j\:/.

Description

1 Title Truck Tipping Bodies Technical Field This invention relates to tipping bodies for trucks and particularly for rear dump trucks. Background Art Rear dump trucks are utilised on mine sites for transporting excavated material to a loading facility or other destination where the transported material is discharged from the truck by tilting the truck body or tray about a rear transverse tipping axis. Typically such rear dump trucks utilise a pair of laterally spaced tipping rams which connect at their lower ends to the truck chassis and to the tipping body forwardly of the rear transverse tipping axis. Tipping bodies for rear dump trucks typically utilise a load containment shell which is designed to position the load so as to provide a desired weight distribution on the axles of the vehicle. Such bodies also have a front extension of the containment shell which provides a shield over the front of the vehicle, including the driving cabin as well as the engine and transmission, to deflect misdirected loads away from the truck and back into the load containment shell which is formed to facilitate free discharge of the material from the containment shell when tipped. As a result such tipping bodies are formed with a relatively smooth uninterrupted inside face and include a central longitudinal base structure which supports the underside of the containment shell and which incorporates laterally spaced apart pivot mounts for the tipping body arranged to achieve the necessary stability of the tipping body in the elevated tipped attitude. Such bodies are subjected to extreme wear and tear and often require replacement. Many tipping bodies are manufactured by specialist manufacturers whose replacement bodies must substantially conform to the standard supporting arrangement provided on the truck by the original equipment manufacturers. The configuration of rear dump trucks used on mine sites provides a relative short longitudinal spacing between the tipping axis and the connection to the tipping rams and thus extremely high loads are applied to the tipping body by the tipping rams. As a result conventional bodies are formed with load spreading 2 reinforcements about the ram connections on the tipping body so as to reduce the induced stress concentrations resultant from forces applied by the rams. In addition as such tipping bodies are mostly fabricated by welding, it is necessary to form reinforcements which terminate at zones of low stress concentration to mitigate failure at weld locations as any such failure decreases the service life of the body. These load spreading reinforcements substantially increase the weight of such tipping bodies and this reduces the payload that the dump trucks can transport. While the payload of such dump trucks can be increased by utilising lightweight tipping bodies, their use results in a shorter service life and/or higher maintenance costs. The weight of such tipping bodies has been reduced in recent years by the use of formable and weldable structural steel plate with a surface hardness comparable with wear plate. This has enabled the production of tipping bodies with internal surfaces having good abrasive wear properties without the need for additional wear plates which previously added considerable weight to the body. The high strength of such plate has also made it possible to reduce the thickness of the floor and wall plates of the containment shell, with the result that tipping bodies can be built which are relatively light. However, as the plate thickness utilised for the body and reinforcing ribs is reduced in the quest for lightweight bodies, at present they become more susceptible to premature fatigue cracking causing increased maintenance costs and/or reduced life. This invention in one aspect aims to provide tipping bodies which will be economical to manufacture and efficient in use. This invention also aims to alleviate at least one of the above-mentioned disadvantages associated with rear dump trucks. Other aspects of this invention will hereinafter become apparent. Summary of Invention With the foregoing in view, this invention in one aspect resides broadly in a method of forming a ram connection between a tipping body and a tipping ram including: providing a load bearing pad capable of being pushed against the underside of the relatively smooth floor of the tipping body by the tipping ram so as to tilt the tipping body about its transverse tipping axis; operatively locating the load bearing pad on the tipping body for operative 3 engagement against the underside of the floor of the tipping body, and forming a ram connection on the underside of the load bearing pad which provides the connection between the tipping ram and the tipping body. The load bearing pad may operatively engage directly against the underside of the floor or a resilient pad or the like may be interposed between the load bearing pad and the floor of the tipping body. Where the tipping body is for a rear dump truck of the type having a containment shell formed with a relatively smooth uninterrupted inside face; a central longitudinal base structure which supports the containment shell; laterally spaced apart pivot mounts adjacent the rear of the base structure about which the containment shell is tipped for dumping a load carried therein, and wherein the load bearing pads are operatively disposed at respective opposite sides of the base structure, the method further includes operatively locating the load bearing pads with respective locating means carried by the central longitudinal base structure. The load bearing pads may be located locating means contained within the central longitudinal base structure, such as by resilient mountings for the load bearing pads formed in the central longitudinal base structure. For example, each locating means may include a transversely extending bar extending through the central longitudinal base structure and connecting to a respective load bearing pad at each side thereof. Furthermore the locating means may be constituted by a pair of longitudinally spaced transversely extending bars extending through the central longitudinal base structure and each being connected to a respective load bearing pad at each side of the central longitudinal base structure. Additional or alternative positioning means may be provided by utilising longitudinal and/or transverse linkages which anchor to the tipping body remote from the load bearing pad. In one embodiment respective longitudinally extending locating links extending between each load bearing pad and fixed support on the tipping body remote from the load bearing pad are utilised to resist longitudinal movement of the load bearing pads which may be urged longitudinally along the tipping by non-perpendicular engagement of the truck's tipping rams with the respective load bearing pads.

4 The positioning means may be or include a bond between the load bearing pad and the tipping body which is capable of transferring shear loads imposed thereon while being incapable of creating undue stress concentrations in the containment shell which is preferably formed with un-reinforced single skin panels at zones about said load bearing pads. According to a further aspect this invention resides in a fabricated tipping body for a dump truck, including a longitudinal base structure supporting a load containment shell, wherein the underside of the containment shell at opposite sides of the longitudinal base structure and forward of the body's rear tipping axis is substantially free of transverse reinforcements and wherein locating means are provided for operatively locating respective load bearing pads against the underside of the containment shell at opposite sides of the central base structure and against which the tipping rams of a dump truck may act to tip the tipping body about its tipping axis. Preferably the containment shell at opposite sides of the longitudinal base structure and forward of the tipping axis is formed as an un-reinforced single skin structure. It is also preferred that the locating means is at least partially supported by the longitudinal base structure such as by forming mountings therein for support members which operatively locate the load bearing pads for actuation by the truck's tipping rams. The locating means may be or may include transversely and/or longitudinally extending linkages supported by the containment shell remote from the surface portions against which the load bearing pads act. The tipping body could be utilised for a dump truck which has the load bearing pads provided on the upper ends of its tipping rams. The locating means may locate a respective load bearing pad at each side of the longitudinal base structure and each load bearing pad may be formed with attachment means on its underside surface for connection to a tipping ram of a rear dump truck. In another aspect this invention resides broadly in a rear dump truck including: a truck supporting a tipping body for tipping about a transverse tipping axis, the tipping body including a longitudinal base structure supporting a load containment shell; 5 extendable rams supported by the truck forwardly of the tipping axis and disposed at respective opposite sides of the longitudinal base structure; each said ram cooperating with a respective load bearing pad operatively located against the underside of the containment shell, and locating means for operatively locating each load bearing pad against the underside of the containment shell. Bief Description of Drawings In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate existing and preferred embodiments of this invention, wherein: Fig. 1 is a diagrammatic side view of a typical rear dump truck illustrating the tipping body in an elevated tipping attitude; Fig. 2 is an underneath perspective view illustrating the reinforcement utilised in existing dump truck tipping bodies; Fig. 3 is an underneath perspective view of a dump truck tipping body according to this invention; Fig. 4 is an enlarged detail of the load bearing pad encircled in Fig. 3; Fig. 5 is a side view of the dump truck tipping body illustrated in Fig. 3; Fig. 6 is a front end view of the dump truck tipping body illustrated in Fig. 3; Figs. 7 and 8 illustrate a dump truck body similar to the body illustrated in Fig. 3 and additionally incorporating a longitudinal link which locates the load bearing pad and supported on a dump truck in transport and tipping mode respectively; Fig. 9 is an underside perspective view of the dump truck body illustrated in Figs. 7 and 8, and Fig. 10 illustrates another method of locating the load bearing pad.

6 Description of embodiments Referring to Fig. 1 it will be seen that a conventional rear dump truck 10 supports a load containment shell 11 formed with an open rear end 12 through which material transported therein is discharged, as illustrated at 13. The shell 11 also has an elevated front tray portion 14 which extends above and shields the driver's cabin of the truck 10 when lowered to the loading and transporting attitude. The shell 11 is supported by a central base structure 15 which provides the rear pivot mounts 16 about which the shell 11 is tipped. The central base structure also supports a pair of ram connections 17 forwardly of the pivot mounts 16 which connect to the upper ends of laterally spaced telescopic tipping rams 18 which are supported at their lower ends by the truck chassis 19. In one form of conventional tipping body 20 the base structure 21 includes a pair of longitudinal rails 22 which support the rear tipping mounts 23 and the ram connections 24. It will be seen that in addition to the longitudinal rails 22, a relatively complex reinforcing structure is used to distribute the loads applied to the containment shell 11 at these locations. The reinforcements include transverse ribs 25 extending from the base structure 21 across the underside of the containment shell 11 as well as longitudinal ribs 26 running from the forwardmost ribs 27. This relatively complex reinforcing structure adds considerable weight to the tipping body 20 and thus substantially reduces its payload. A tipping body 30 according to one embodiment of this invention, as illustrated in Figs. 3 to 6, is provided as a replacement for a conventional tipping body for a rear dump truck and thus connects to the original pivot supports16 and the tipping rams 18 provided on the rear dump truck 10. The tipping body 30 incorporates a pair of spaced longitudinal frames 31 which extend in spaced apart relationship centrally along the underside of the body 30 to provide the complementary transversely spaced tipping mounts 32 which connect to the pivot supports 16 provided on the truck 10 and which provide operative location for the body 30 in its lowered position. The frames 31 also provide resilient supports 37, illustrated in more detail in Fig. 4, for the separate load bearing pads 34, each of which in use, bears against the underside of a respective side floor panel 36 of the containment shell 11 through a resilient pad 35.

7 In this embodiment of the invention, the floor panels 36 of the containment shell 11 at opposite sides of the longitudinal frames 31 are formed as single skin floor panels which extend uninterrupted from a rear stiffening beam 40, which limits outward deflection of the side walls 42 when loaded, and a U-shaped reinforcing beam 41 which extends substantially horizontally along the side walls 42 from the stiffening beam 40 and across the front wall 43 from which the elevated front tray portion 14 extends. As is more clearly illustrated in Fig. 5 the transition between the side floor portions 36 and the front wall 43 is formed as a large radius curve so as to minimise stress concentrations which would occur at small radius bends or straight angle joints between the floor panels 36 and the front wall 43. As a result of this configuration the undersides of the respective side floor panels 36 are plain surfaces, that is the floor panels are formed without abrupt cross sectional discontinuities which could form localised stress concentrations. The longitudinal frames 31 are provided with transversely aligned tubular mounts 45 through which interconnecting bars 47 pass to support the load bearing pads 34. For this purpose each pad 34 is provided with transversely spaced side plates 48 which are bushed at each end at 49 to engage about the ends of the interconnecting bars 47 which project outwardly from the longitudinal frames 31. Each pair of side plates 48 also provides a central mounting 50 for connection to the upper end of a tipping ram 18. The tubular mounts 45 could be bushed with resilient bushes 46 to ensure that the tipping rams 18 act against the floor panels of the tipping bin through the load-bearing pads. Alternatively the interconnecting bars could flex or be loosely mounted in the tubular mounts to ensure that they do not transfer a significant ram force into the longitudinal base structure. For this purpose the interconnecting bars could extend through respective slots and preferably vertical slots formed in the base structure. In use the load bearing pads 34 bear against the underside of the floor panels 36 such that extension of the tipping rams 18 will pivot the forward end of the body 30 upwardly about the tipping mounts 32. During this action, due to the geometry of the ram and pivot mounts on the truck 10, the rams 18 will initially provide a force component tending to move the load bearing pads 34 rearward along the panels 36 followed by a transition to a forward force 8 component tending to move the load bearing pads 34 forward along the panels 36. These force components will be resisted by the transverse bars 47 acting against the tubular mounts 45 in the longitudinal frames 31, or the vertical slots, if utilised. While flexing of the floor panels 36 outwardly of the central frames 31 may occur during tipping operations, any such flexing or distortion of these floor panels 36 will not create areas of localised high stress. This deflection will be at least partially resisted by the load carried in the containment shell which will be distributed over the floor of the tipping body 30. The dump truck 50 illustrated in Figs. 7, 8 and 9 has a tipping body 51 which is substantially identical to the tipping body 30 with additional location of each load bearing pad 34 provided by a compression/tension link bar 52 extending from the rearmost mounting 49 on the load bearing pad 34 to a rear transverse bar connection 53 supported on the tipping body 51 rearward of the U-shaped frame 54. As illustrated, each link bar 52 will act as a compression member to resist rearward movement of a respective load bearing pad 34 during initial tilting of the body 51 and when fully tilted, the link bars 52 will be acting as tension members resisting forward movement of the respective load bearing pads 34 along the underside of the floor portions 56. In both embodiments no significant transverse force component is applied to the load bearing pads 34 and any slight force component will be resisted either by the frictional engagement between the load bearing pads 34 and the underside panels 36 of the tipping bodies or directly by the interconnecting bars 47. Fig. 10 illustrates a further linkage arrangement 60 for locating the load bearing pads, one of which is illustrated at 61, adjacent the floor 62 of the containment shell 11. Each pad 61 is connected to the upper end of a respective lifting ram 18 and is positioned by trailing links 63 and 64 supported by a leading transverse interconnecting bar 65 and a trailing transverse interconnecting bar 66 respectively, which are supported by the longitudinal frames 31. The leading bar 65 is a relatively large diameter bar able to resist the shear loads applied by the rams 18 during tipping operations while the smaller transverse bar 66 provides additional operative location of the load bearing pad 61. The links 63, 64 extend to the mounts 49 at the leading and trailing ends of the transversely spaced side plates 48.

9 While the above described embodiments utilise large radius or substantially flat panel portions against which the separate load bearing pads push, these panel portions could be formed as non-planar panels such as corrugated panels and if desired the load bearing pads could have a conforming shape. It will be seen that in the illustrated embodiments the ram attachments are isolated from the tipping body shell structure so that in use, high stress concentrations are removed or significantly lessened by simplifying the structural arrangement of the tipping body. This simplified structure which may be fabricated by welding, will be lighter than an existing fully reinforced welded structure and when fabricated using wear resistant plate as mentioned above will enable higher payloads to be carried without overloading the truck 10. In addition a replacement tipping body may be provided which does not change the nature of the rear dump truck operation or require significant change to the supporting truck for its adaption. It will of course be realised that while the above has been given by way of illustrative example of this invention, all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is defined in the appended claims.

Claims (16)

1. A method of forming a ram connection between a tipping body and a tipping ram including: providing a load bearing pad capable of being pushed against the underside of the relatively smooth floor of the tipping body by the tipping ram so as to tilt the tipping body about its transverse tipping axis; operatively locating the load bearing pad on the tipping body for operative engagement against the underside of the floor of the tipping body, and forming a ram connection on the underside of the load bearing pad which provides the connection between the tipping ram and the tipping body.

2. A method as claimed in claim 1, wherein the tipping body is of the type having a containment shell formed with a relatively smooth uninterrupted inside face; a central longitudinal base structure which supports the containment shell; laterally spaced apart pivot mounts adjacent the rear of the base structure about which the containment shell is tipped for dumping a load carried therein, and wherein the load bearing pads are disposed at respective opposite sides of the base structure, the method further including operatively locating the load bearing pads with respective locating means carried by the central longitudinal base structure.

3. A method as claimed in claim 2, wherein each locating means includes a fixed support carried by resilient mounting means in the central longitudinal base structure.

4. A method as claimed in claim 2 or claim 3, wherein each locating means includes a transversely extending bar extending through the central longitudinal base structure and connecting to a respective load bearing pad at each side thereof.

5. A method as claimed in claim 3, wherein the locating means is provided by a pair of longitudinally spaced transversely extending bars extending through the central longitudinal base structure and each being connected to a respective load bearing pad at each side of the central longitudinal base structure. 11

6. A method as claimed in any one of claims 3, 4 or 5 and further providing a respective longitudinally extending locating link extending between each load bearing pad and a fixed support on the tipping body remote from the load bearing pad.

7. A method as claimed in any one of the preceding claims, including forming the tipping body zones about said load bearing pads as un-reinforced single skin panels.

8. A fabricated tipping body for a dump truck, including a longitudinal base structure supporting a load containment shell, wherein the underside of the containment shell at opposite sides of the longitudinal base structure and forward of the body's rear tipping axis is substantially free of transverse reinforcements and wherein locating means are provided for operatively locating respective load bearing pads against the underside of the containment shell at opposite sides of the central base structure and against which the tipping rams of a dump truck may act to tip the tipping body about its tipping axis.

9. A fabricated tipping body as claimed in claim 8, wherein the containment shell at opposite sides of the longitudinal base structure and forward of the tipping axis is formed as an un-reinforced single skin structure.

10. A fabricated tipping body as claimed in any one of claims 8, 9 or 10, including locating means carried by the central longitudinal base structure for operatively locating the load bearing pads.

11. A fabricated tipping body as claimed in claim 10, wherein the locating means includes a fixed support carried by resilient mounting means in the central longitudinal base structure.

12. A fabricated tipping body as claimed in claim 11, each locating means includes a transversely extending bar extending through the central longitudinal base structure and connecting to a respective load bearing pad at each side thereof.

13. A fabricated tipping body as claimed in claim 12, wherein the locating means is provided by a pair of longitudinally spaced transversely extending bars extending through the central longitudinal base structure and each bar being connected to a respective load bearing pad at each side of the central longitudinal base structure. 12

14. A fabricated tipping body as claimed in any one of claims 8 to 13, wherein the locating means for each load bearing pad includes a respective longitudinally extending locating link extending between the load bearing pad and a fixed support on the tipping body remote from the load bearing pad.

15. A rear dump truck assembly including: a truck supporting a tipping body for tipping about a transverse tipping axis, the tipping body including a longitudinal base structure supporting a load containment shell; extendable rams supported by the truck forwardly of the tipping axis and disposed at respective opposite sides of the longitudinal base structure; each said ram cooperating with a respective load bearing pad operatively located against the underside of the containment shell, and locating means for operatively locating each load bearing pad against the underside of the containment shell.

16. A rear dump truck assembly as claimed in claim 15, wherein said tipping body is of the type having: a containment shell formed with a relatively smooth uninterrupted inside face; a central longitudinal base structure which supports the containment shell, and laterally spaced apart pivot mounts adjacent the rear of the base structure about which the containment shell is tipped for dumping a load carried therein, and wherein the load bearing pads are disposed at respective opposite sides of the base structure.