GB2306445A

GB2306445A - Transport container bodies

Info

Publication number: GB2306445A
Application number: GB9521585A
Authority: GB
Inventors: George Hugh Edmond; Anthony George Haynes
Original assignee: FRUEHAUF CRANE Ltd
Current assignee: FRUEHAUF CRANE Ltd
Priority date: 1995-10-20
Filing date: 1995-10-20
Publication date: 1997-05-07
Anticipated expiration: 2015-10-20
Also published as: GB9521585D0; GB2306445B

Abstract

A transport container roof beam which in use, is supported by at least two uprights spaced along the beam incorporates a cable, chain, strip or other elongate tension member which is fitted to and extends along at least a portion of the length of the beam and which bows the beam so that the beam resists the tendency to deflect under its own temporarily unsupported weight during loading and unloading of the container with the uprights removed.

Description

IMPROVEMENTS TO CONTAINERS Field of the Invention This invention relates to improvements to containers, in particular to road or rail haulage containers.

Background to the Invention In the haulage business, there is a widely used transport container body used for the carriage of goods known as a "curtain sider" body.

This type of body has a roof which may be of the fixed or opening type possessing a fixed front bulk head and generally having an entrance at the rear. This entrance may be closed by means of hinged doors, curtains, roller shutters, tail-gate or tail lift. In some cases the rear bulk head could also be of the fixed type, for example, when no end loading or unloading is necessarv.

In these types of transport container bodies, side access to the interior of the body is made available by opening a curtain on one or both sides of the container. Typically, the curtain runs along a track at the outside edge of the roof. Such transport container bodies can be fitted to lorries, road trailers.

rail cars and inter-model containers.

The "tensioners" used to secure the curtain to the floor of the chassis when the transport container is in use, together with the need in many instances, to secure loads to the under side of the roof of the containers, has meant that traditionally, the main horizontal roofing beams have been made from steel.

Reducing the mass of each respective roof beam without reducing the integrity of the container, would enable greater pay loads to be carried for a given gross weight of container transport body.

Furthermore, as each respective roof beam is primarily fixed to the chassis or base frame of the container via the front and rear bulk head, the dynamic forces (acceleration, braking, cornering) that act on the joints securing the roof to the bulk heads and the bulk heads to the chassis (Fig 1) are directly proportional to the total weight of the roof. Therefore, any reduction in the weight of the roof would prolong the longevity of such transport container bodies and reduce their maintenance requirements.

Whilst it is possible to construct a roof with a low mass from aluminium alloy or similar raw materials which will be adequate during road or rail travel, the use of such a low mass roof gives a further operational problem that is not generally acceptable to operators of such transport container bodies.

During road or rail operation the roof is generally supported by one or more side pillars (Figure 2). However, during the loading or unloading process, these pillars have to be removed either completely, or alternatively, moved temporarily to the end of the transport container body (Figure 3) to give good access for the loading or unloading of cargo.

When the pillars are removed from their normal supporting position, the roof tends to sag or deflect downwards (Figure 3) reducing the height of the side aperture and limiting the size of the cargo that can be loaded or unloaded.

Roofs whose main longitudinal beam is constructed from aluminium alloy or similar lightweight materials will sag approximatelv three times more than conventional steel beams of the same physical shape and size. This is generally an unacceptable constraint placed on the operator during the loading and unloading process.

It is an object of the invention to alleviate this problem and whilst it is embodied in ttvo independent aspects, it will be apparent from this broad background review that both these aspects are so linked as to form part of the same inventive concept.

Summarv of the Invention According to a first aspect of the invention, there is provided a transport container roof beam which in use, is supported by at least two uprights spaced along the beam so as to experience, as is conventional with such beams, significant deflection of the beam from its normal substantially linear operating condition when, as again is conventional, the uprights are temporarily removed to allow the container to be loaded or unloaded; characterised in that the beam incorporates a cable, chain, strip or other elongate tension member which is fitted to and extends along at least a portion of the length of the beam and which bows the beam so that the beam resists the tendency to deflect under its own temporarily unsupported weight during loading and unloading.

Preferably, the tension member in use, is fitted to the lower surface of the beam in the beam's normal attitude of operation.

Preferably, the tension member is provided with means to enable the tensioning force exerted on the beam in use to be varied.

The invention includes within its scope a transport container roof beam substantially as herein described with reference to and as illustrated bv Figures 5 and 7 in the accompanying diagrams; since this represents the best wav currently known to the applicant of putting the invention into practice.

The invention further includes within its scope, a transport container body provided with a transport container roof beam in accordance with any of the arrangements specified above.

According to a second aspect of the present invention, there is provided a method of manufacturing a transport container roof beam comprising the steps of: i) supporting a beam member at substantially each of its ends with uprights of sufficient height to enable the beam to deflect under its own weight to come to rest in a new equilibrium position; ii) whilst the beam is in this new equilibrium position, securing an elongate tension member to the beam so as to extend along at least a portion of the length of the beam and to bow (i.e hold under tension) the beam in that position; iii) and then inverting the beam prior to installing it on the container.

Brief Description of the Drawings Figure 1 shows a schematic side view of where the dynamic forces act on a transport container body whilst in motion.

Figure 2 shows a schematic side view of a transport container body provided with uprights or side pillars during transportation to prevent roof sag or deflection.

Figure 3 shows a schematic side view of the deflection or sag experienced by a transport container body once these uprights or side pillars have been removed for loading or unloading purposes.

Figure 4 shows a schematic side view of a roof beam deflecting to a new equilibrium position under its own weight when supported at each end by uprights.

Figure 5 shows a schematic section view through a roof beam illustrating various ways of attaching or locating a tension member to or on the beam.

Figure 6 is a schematic side view showing the apparent difference in length between the inner (lower) surface X of a beam and the nutter (upper) surface Y of a beam when deflected.

Description of the Preferred Embodiments As illustrated in Figure 6 the distance X illustrates the concave surface of the deflected roof beam and distance Y illustrates the convex surface of a similar deflected roof beam. For the avoidance of doubt, throughout this specification, concave surface X will be the lower surface of the roof beam when the roof beam forms part of the transport container body.

The tenn tension member throughout this specification is intended to have a very broad meaning covering for example, cables, chains, strips of material that may or may not be apertured, and shaped materials for example those whose longitudinal cross-sections are substantially T' or "H" shaped.

Referring now to Figures 4 and 7, Figure 4 shows a transport container roof beam that has been allowed to deflect under its own weight to a new equilibrium position. Whilst in this position, a tension member is welded to the lower surface of the beam. The beam and tension member are now inverted (see Figure 7) and the beam is allowed to try and re-establish its substantially linear configuration. As it does so, the tension member is brought under tension and as a consequence, resists the attempt by the beam to reconfigure into a substantially linear configuration.In such an arrangement, when such a beam fitted with a tension member is erected to form part of a roof of a transport container body, the new equilibrium position established by the mutually antagonistic forces exerted by the tension member and the beam (the latter essentially being gravitational forces), is one that essentially maintains the transport container roof beam in a substantially linear configuration. In effect, the tension member "bows" the beam.

Of course, this embodiment has been described bv way of example only and a number of modifications can be made without departing from the scope of the invention. For example, the tension member could be rivetted or otherwise secured to the beam along its length. In alter..ative embodiments (not illustrated), the means of attaching the tension member to the lower surface of the beam need not involve securing through welding, riveting or otherwise, the tension member along its entire length. For example, the tension member can be secured to the beam through a securing means confined to each respective end of the tension member.

Figure 7 illustrates a tension member that is substantially smaller in length than the lower surface of the beam that it is attached to. In alternative embodiments (not illustrated), the tension member could occupy substantially the entire length of the lower surface of the beam when fitted to it.

Figure 5 illustrates a cross-section through a transport container roof beam with its lower surface accommodating two different types of tension member.

In one embodiment, the tension member is similar to the one illustrated in Figure 7 whilst in the other embodiment the tension member is a cable fitted to a conventional beam that has been adapted to receive it through the incorporation of a groove or channel that runs throughout substantially the entire length of the lower surface of the beam. It will be noted, that in this particular embodiment the groove or channel is sized and shaped to accommodate substantially the full diameter of the tension member so that it does not encroach on the available chassis-to-roof loading space when in use.

In alternative embodiments (not illustrated), channels or grooves of various depths could be used. some exposing a portion of the tension member below the lower surface of the beam.

In yet further embodiments (not illustrated) multiple tension members could be used to support the beam in side-to-side substantially parallel alignment along substantially the length of the beam.

In Figures 5 and 7, the material used to produce the tension member is not specified in itself. If the material is used not the same as the beam but is still metallic in nature, the possibility of electrolytic couples forming, encouraging corrosion of either the tension member, beam or both is a distinct possibility.

Therefore, in such embodiments the beam, tension member or both could be provided with a barrier coating (e.g through either conventional powder coating technology or solvent based painting processes). Either the whole beam or tension member can be subjected to the barrier forming process or alternatively only those parts of the beam or tension member liable to come into contact with each other can be subjected to the process. Other methods of providing barrier surfaces can be selected without any further inventive thought by the skilled addressee of this specification.

The embodiments so far described only cover tension members whose tensioning force once fitted to the beam cannot be varied.

In alternative embodiments (not illustrated), it is envisaged that the tensioning force of the tension member can indeed be varied through, for example, a ratchet and pawl mechanism that is also provided with a locking means. One can envisage for example, a cable type tension member fitted to a roof beam and extending through at least one side beam of the transport container body and subsequently running down the outside surface of the transport container body and entering a hand or electrically driven ratchet and pawl adjustment mechanism.

Of course, the ratchet and pawl mechanism is described by way of example only and the specification is not intended to be restricted to such a mechanism.

Claims

1. A transport container roof beam which in use, is supported by at least two uprights spaced along the beam so as to experience, as is conventional with such beams, significant deflection of the beam from its normal substantially linear operating condition when, as again is conventional, the uprights are temporarily removed to allow the container to be loaded or unloaded; characterised in that the beam incorporates a cable, chain, strip or other elongate tension member which is fitted to and extends along at least a portion of the length of the beam and which bows the beam so that the beam resists the tendency to deflect under its own temporarily unsupported weight during loading and unloading.

2. A transport container roof beam as claimed in Claim 1 characterised in that the tension member in use, is fitted to the lower surface of the beam in the beam's normal attitude of operation.

3. A transport container roof beam as claimed in either Claim 1 or Claim 2 characterised in that the tension member is provided with means to enable the tensioning force exerted on the beam in use to be varied.

4. A transport container roof beam substantially as herein described with reference to and as illustrated by Figures 5 and 7 in the accompanying diagrams.

5. A transport container body provided with a transport container roof beam in accordance with any of the Claims specified above.

6. A method of manufacturing a transport container roof beam comprising the steps of: i) supporting a beam member at substantially each of its ends with uprights of sufficient height to enable the beam to deflect under its own weight to come to rest in a new equilibrium position; ii) whilst the beam is in this new equilibrium position, securing an elongate tension member to the beam so as to extend along at least a portion of the length of the beam and to bow (i.e hold under tension) the beam in that position; iii) and then inverting the beam prior to installing it on the container.