Road tanker

Abstract: A tank (10) to transport liquids, and a method of manufacturing the tank (10). The tank (10) has a floor portion (21) which is provided with transversely extending pairs of slots (30) into which extend flanges (33) of dividing walls (17, 18). The flanges (33) extend through the slots (30) so as to provide external mountings, for example wheel assemblies. The longitudinally extending floor portion (21) conforms to portions of frusto-conical surfaces so that the cross-sectional area of the tank (10) increases rearwardly of the tank (10).

Description: This invention relates to tanks to transport liquid and more particularly but not exclusively to road tankers, according to the characteristics of the preamble of independent claim 1, and to a method of manufacturing such tanks according to the characteristics of the preamble of independent claim 7. Road tankers have their vessels formed of an elongated shell which encloses a chamber to receive the liquid to be transported. Extending transverse of the chamber and welded to the internal surfaces of the shell, are dividers and baffles. The above discussed vessel is formed by providing an aluminium sheet to form the bottom of the shell and welding to that two side panels. Initially, the baffles and/or dividers are held in position in a generally vertical orientation, but inverted. The bottom panel and side panels are then placed over the dividers and/or baffles and deformed to conform to the external peripheral profile of the baffles and/or dividers. This is achieved by pulling the side panels downward over the dividers and/or baffles. As the shell material deforms, it is welded in position to retain its deformed configuration. To the above vessel adjacent the location where the dividers and/or baffles are welded to the shell, there is welded to the external surface of the shell, various mountings for the wheel assemblies and other apparatus. It should be appreciated that when the above described vessel is being formed, the vessel is formed inverted and must subsequently be righted for completion. The above discussed method of manufacturing a mobile tank suffers from several disadvantages including having to weld to the shell the above discussed mounting points. These extra welds can result in providing a vulnerable zone in the overall structure. US-A-3 131 949 describes a tank comprising the features of the preamble of independent claim 1. It is an aim of the present invention to overcome or substantially ameliorate the above disadvantages. According to the present invention there is provided a tank to transport liquid, said tank comprising: an elongated shell enclosing an elongated chambers to receive the liquid; a plurality of walls extending transversely of said chamber at longitudinally spaced locations along the chamber wherein each said wall comprises a peripheral edge portion abutting an internal surface of a floor portion of said shell, said floor portion of said shell being curved to conform to the profile of said wall characterised by flanges downwardly projecting from said walls, and projecting through transversely extending slots formed in said floor portion of said shell said flanges providing mounting means externally of said shell at longitudinally spaced locations along the shell. Preferably the slots are arranged in pairs which are aligned transversely of the chamber, and each wall has a pair of flanges which project into or through an associated pair of slots. The invention further provides a method of manufacturing a tank to transport liquids, said method comprising the steps of: providing a sheet of aluminium material with a central elongated portion thereof being adapted to provide a floor portion of the tank; providing a plurality of walls to be located internally of said tank; locating said walls with respect to said floor portion (21) so that said walls are transversely arranged and longitudinally spaced; deforming said sheet by pulling it around the peripheral edges of the walls so as to conform to the profile thereof; securing said sheet to said walls; characterised in that prior to locating said walls with respect to said floor portion, said floor portion is provided with a plurality of transversely extending slots to receive downwardly projecting flanges provided on said walls; said step of locating said walls with respect of said floor portion comprises placing said walls on said floor portion so that said flanges locate in said slots; said step of deforming said sheet causes said flanges to project through said slots thereby to provide external mountings at longitudinally spaced locations along the tank. The present invention will be further described hereinafter by reference to the following description of an exemplary embodiment and the accompanying drawings wherein Figure 1 is a schematic side elevation of a tank for a road tanker; Figure 2 is a schematic top plan view of the tank of Figure 1; Figure 3 is a schematic front elevation of a divider wall employed in the tank of Figure 1; Figure 4 is a schematic top plan view of the divider wall of Figure 3; Figure 5 is a schematic plan view of the sheet to form the tank floor; Figure 6 is a schematic sectioned front elevation of one side of the tank of Figure 1; Figure 7 is a schematic rear elevation of the tank of Figure 1; Figure 8 is a schematic sectioned side elevation of a side wall of the tank of Figure 1; Figure 9 is a schematic sectioned end elevation of the side wall of Figure 8; and Figure 10 is a schematic plan view of the side wall of Figure 8. In the accompanying drawings there is schematically depicted a vessel 10 of a road tanker. The vessel 10 consists of a shell 11 encompassing a chamber 12 to receive a liquid to be transported. The forward end of the vessel 10 is provided with a forward bulkhead 12 which is convex and which has adjacent its extremities a hollow section 13 which acts as a reinforcement in that area which aids in minimising damage to the vessel 10 should the forward corners of the shell 11 receive an impact. The rear bulkhead 14 is concave and extends at its extremities to hollow sections 15 which aid in reinforcing the rear extremities of the vessel 10 to aid it in resisting an impact in that area. The concave configuration of the bulkhead 14 also acts to minimise aerodynamic drag. Since the bulkhead 14 extends to vertically extending edges 16 it sheds vortices from these vertical edges 16. Extending transversely across the chamber are dividers 17 and/or baffles 18. Each of these dividers 17 and baffles 18 is secured to a side panel 19 via mountings 20. Each mounting 20 is vertically extending and is of a generally "U-shaped" transverse cross section. In Figures 3 and 4 there is schematically depicted one of the dividers 17. The shell 11 consists of the side panels 19, a floor panel 21 and a roof panel 22. Each side panel 19 consists of a sheet 23 joined at its upper end to a hollow section 24 which reinforces the upper edges of the tank 10 to again aid in strengthening the tank 10 against impact, particularly impact resulting from a rollover. The side panel 19 extends to an upper sheet 25 of the roof panel 22 which upper sheet 25 is also provided with a hollow section 26 again designed to aid in strengthening the tank 10 against an impact which may result from a rollover. The sheet 23 is deformed adjacent its lower portions so as to follow the contour 27 at the forward end of the tank 10, and to follow the contour 28 adjacent the rear of the tank 10. The mean profile is illustrated by the contour 29. The contours 27, 28 and 29 are portions of a circle. The floor panel 21 is formed from a flat sheet. The panel 21 is cut to provide transversely extending slots 30 which are generally arcuate. In Figure 5, the floor panel 21 is illustrated in its flat form prior to being deformed to its curved configuration in the formed vessel 10. The floor panel 21 is also provided with further slots 31 which also extend generally transverse of the longitudinal axis 32 of the floor panel 21. As best seen in Figure 5, the slots 30 and 31 are arranged in pairs extending transverse of the longitudinal axis 32. Each of the side panels 19 is provided with a plurality of the mountings 20. Each of the dividers 17 and/or baffles 18 are welded to associated transversely aligned mountings 20. Each of the dividers 17 and/or baffles 18 are provided with downwardly projecting pairs of flanges 33 which are intended to project through the pairs of slots 30 or 31. The flanges 33 provide mountings for wheel assemblies and other apparatus to be secured to the vessel 10. In Figures 3 and 4, the flanges 33 are illustrated as receiving adaptors 34 to adapt the flanges 34 to provide mountings for the wheel assemblies. The above described tank is of an aluminium construction. In manufacturing the tank 10, the floor panel 21 is first welded to the pre-assembled side panels 19. Thereafter, the floor panel 21 is supported so as to assume its intended configuration. Thereafter, the dividers 17 and/or baffles 18 are placed in position so as to extend downwardly through their associated slots 30 or 31. The flanges 33 then project through the floor panel 21. While the dividers 17 and/or baffles 18 are held in position, the side panels 19 are pivotted upwardly to a position where the mountings 20 abut their associated divider 17 and/or baffle 18. While this process is taking place, the panels 19 and 21 are being welded in position. Thereafter, the roof panel 22 may be added or alternatively folded in position with the side panels 19. This operation may be conveniently performed by placing the unformed shell 11 in a sling. It should be appreciated that the floor panel 21 is shaped to provide the tank 10 with an increasing transverse cross section toward the rear of the tank 10. This is achieved by having the floor panel 21, in its finishied profile, conforming generally to portions of three frusto-conical surfaces. The central portion of the floor panel 21 conforms basically to a frusto-conical surface which tapers rearwardly. The side portions of the panel 21 conform to frusto-conical surfaces which taper forwardly. By having the various portions of the floor 21 conform to various frusto-conical surfaces, the panel 21 can be deformed without buckling since it will bend about generally straight lines extending longitudinally of the panel 21.

Claims: A tank (10) to transport liquid, said tank (10) comprising: an elongated shell (11) enclosing an elongated chamber (12) to receive the liquid; a plurality of walls (17,18) extending transversely of said chamber (12) at longitudinally spaced locations along the chamber (12) wherein each said wall (17,18) comprises a peripheral edge portion abutting an internal surface of a floor portion of said shell, said floor portion (21) of said shell being curved to conform to the profile of said wall (17,18) characterised in that each said wall (17,18) further comprises downwardly projecting flanges, projecting through transversely aligned transversely extending slots (30,31) formed in said floor portion (21) of said shell (11) said flanges (33) providing mounting means externally of said shell (11) at longitudinally spaced locations along the shell (11). The tank (10) of claim 1, wherein said slots (30) are arranged in pairs which are aligned transversely of the chamber (12), with each pair of slots (30, 31) being associated with a respective one of the walls (17, 18) and each wall (17, 18) has a pair of said flanges (33) which project into an associated pair of the slots (30, 31). The tank (10) of claim 1 or 2, wherein the transverse cross-sectional area of said chamber (12) increases from a forward end of said tank (10), to a rear end of said tank (10). The tank (10) of any preceding claim wherein a central section of said floor portion (21) generally conforms to a frusto-conical surface extending longitudinally of the tank (10) and having its longitudinal axis aligned longitudinally of the tank (10). The tank (10) of claim 4 wherein the frusto-conical surface of said central section tapers away from said or a forward end. The tank (10) of claim 5 wherein side sections of said floor portion (21) generally each conform to a frusto-conical surface extending longitudinally of the tank (10) and having its longitudinal axis aligned longitudinally of the tank wherein said frusto-conical surfaces of said side sections of said floor portion taper towards said foreward end. A method of manufacturing a tank (10) to transport liquids, said method comprising the steps of: providing a sheet of aluminium material with a central elongated portion thereof being adapted to provide a floor portion (21) of the tank (10); providing a plurality of walls (17,18) to be located internally of said tank (10); locating said walls with respect to said floor portion (21) so that said walls (17,18) are transversely arranged and longitudinally spaced; deforming said sheet by pulling it around the peripheral edges of the walls (17,18) so as to conform to the profile thereof; securing said sheet to said walls (17, 18); characterised in that prior to locating said walls (17,18) with respect to said floor portion (21), said floor portion (21) is provided with a plurality of transversely extending slots (30,31) to receive downwardly projecting flanges (30) provided on said walls; said step of locating said walls with respect of said floor portion comprises placing said walls (17,18) on said floor portion (21) so that said flanges (33) locate in said slots (30,31); said step of deforming said sheet causes said flanges (33) to project through said slots (30,31) thereby to provide external mountings at longitudinally spaced locations along the tank (10). The method of claim 7, wherein said walls (17,18) are selected such that when said sheet is deformed by pulling it around the peripheral edges of the walls (17,18) said sheet deforms by bending about straight lines extending longitudinally of the tank (10). The method of claim 8, wherein said straight lines follow frusto-conical surfaces, which frusto-conical surfaces have their longitudinal axes extending longitudinally of the tank (10). The tank of any one of claims 1 to 6, wherein said tank further comprises a wheel assembly supporting said shell (12) via said flanges (13), wherein the flanges (13) provide mountings for said wheel assembly.

Inventors: DINGLE TREVOR, DINGLE, TREVOR
Applicants: HOCKNEY PTY LTD, HOCKNEY PTY LIMITED
Application year: 1992
Main classification: B60P3
IPC codes: B65D88, B65D90, B60P3