GB2355451A - Flatrack with extended corner posts - Google Patents

Abstract

A collapsible flatrack container has the ability to receive corner post extensions 17 without the need to alter substantially the structure of the container. To this end, the recesses in the side web are made large enough during manufacture to take an extension whether fitted or not. Preferably, the end post is provided with a lock 25, 26 to hold the post collapsed which does not involve the usual top fitting 3. The extension can be removably fitted to the post or welded thereto.

Description

2355451 Title: A collapsible flatrack with extendable posts

In the field of shipping containers there is a series of containers called collapsible flatracks comprising a platform base with erect posts normally at either end though sometimes toward the middle. The posts fold down onto or adjacent to the base to allow the folded flatracks to be stacked one upon another for economical transport and storage. Such collapsible flatracks have been around for decades and are described in many an earlier patent such as Howe.....

Most commonly the posts are joined top and bottom by horizontal members called rails and these have a panel wall welded to them to form an assembly called an end wall. When these end walls fold down onto the base there are provided recesses in the base to receive the bulk of the rails and posts such that the panel lies flat on the floor of the base and the flatrack can be used as a simple cargo carrying platform with cargo being placed on the exposed base and over the folded end wall.

Flatracks are used for tall cargos which are too high to fit inside a common enclosed freight container. However even.then the cargo can be taller than can be fitted within a normal typically 8ft6in high flatrack. So recently there has been a move to make flatracks 9ft6in high but these then can not always fit within transport infrastructure and require special trucks and wagons to carry them under say, low bridges on route. So the decision to purchase fixed height 9ft6in flatracks or taller is difficult. A more temporary solution is to be preferred which could be fitted when needed and allowed yet not restrict less tall cargos on less tall flatracks transported on another day.

So it would be an advantage to have posts which are 1 telescopic or which could be extended in some way. The extensions could be made removable but this can lead to their getting lost. So a fixed extension is preferred which can also be cheaper, stronger and more secure if welded on direct to the existing post rather than bolted or pinned in some way.

With a permanent or semi-permanent extension, the post must have space made within the base to allow it to fold into recesses in the base. Such recesses are typical of collapsible flatracks and considered the norm but are not large enough to receive something extra such as an extension. Known recesses are cut into the base structure and can cause the stress to be raised substantially. So substantial reinforcements can be needed. If the recess is increased to accept say 8ft6in and taller, say 9ft6in high posts, then so too is the reinforcement weight and cost increased. A way around such a cost increase would be an advantage. -However if there is no extended recess, then the extensions would have to be removed before folding the posts with all the attendant problems that this implies.

The posts are counterbalanced by springs to assist in the manual folding and erections of the posts. When extensions are added to the posts, the weight increases and this- in turn necessitates an increase in the resilience of the springs. If the springs could be made more resilient by simple adjustment, then this would be an advantage.

When the posts are folded down, the springs tend to cause the posts to erect themselves, and it thus a matter of safety that the posts are locked down by some means in the folded positions. The normal method is to lock the posts by a device engaging the apertures in the top corner fittings. However with an extended post, such a lock would need to be cut off and repositioned also. So a means independent of the top casting for locking the posts down would be an 2 advantage.

The present invention comprises a platform based container with folding posts which fold into recesses in the base, the recesses being formed to receive standard height posts and extended posts without structural modification.

The preferred embodiments of the invention will now be described by way of example only with reference to the following figures.

In figure 1A there is seen a perspective view of a typical collapsible flatrack in the post erect position, and in figure 1B a perspective view of a typical collapsible flatrack in the post folded position.

In figure 2 there is seen a side elevation of the base where the fittings 3 and top rail 9 fold down into recesses in the base and the side view of the hinge arrangement is seen.

In figure 3 there is seen an end elevation in section of the recess with the top fittings folded in place.

In figure 1A there is seen a typical collapsible flatrack having a platform base 1, and end wall 7 comprising posts 2.at each corner of one end, top and bottom rails 9 and end panel 8. The posts 2 terminate at the top with corner fittings 3 comprising rectangular steel boxes with handling apertures formed in their three outermost sides. The posts 4 seen at the other end have been extended by extensions 5 fixed to the fittings 3.

Proprietary extensions can be bought or other designs constructed which connect to the top corner fittings of containers. These extensions can be attached to the top fittings 3 by removable means such as bolts or twistlocks, the bolts being removable easily if required or by other 3 means needing destruction of the bolts before removal could take place. They can be removed if required or more advantageously left in situ. Extensions can be manufactured and welded onto the top fittings so that they cannot be removed except by cutting.

In figure 1B the end wall 7 has been folded down and the posts 2 have folded into recesses 10' denoted by dotted line in figure 1A within the plan profile of the base 1. Top and bottom rails 9 have folded into recesses 10, and the panel 8 lies on top of floor 23.

In figure 2, there is seen a side elevation of the base where the fittings fold down into recesses 10 in the base. In this example the extension comprise comprise a strut 17 of steel tube and capped by a simple plates profiled to the plan shape of a corner fitting complete with a top lift aperture formed in it. It is envisaged that the strut 17 could be any suitable section to support the stacking and handling loads likely, and the top plate 6 might be substituted by a complete corner fitting such as top fitting 3.

The fittings 3 and top plate 6 can be seen in their respective positions. Strut 17 has been welded onto the fitting 3 to provide the strength requirements of the flatrack. When erect water can enter the aperture in the top plate 6 and this can drain out through the apertures in corner fitting 3.

If required to be removed, the welded strut 17 can be ground off or removed in some other way. It has been found that the steel casting material of corner fitting 3 is tolerant to such treatment and is of substantial thickness of steel such that this adding and removal can be carried out several times without loss of performance.

4 A lock 11 locks the posts 2 in the down position. The lock 11 comprises typically a bolt 25 which engages with a plate 26 fixed to the post 2 through which is drilled a hole to receive the bolt 25. It is seen to be located and operational independent of the fittings 3 or top plate 6 and thus whatever position of fitting or top plate there is, the lock remains in the same place without need of modification.

A spring 12 is seen in tensioned position adjacent to the hinge 11 via a lever arm 13 which causes a lifting moment on the hinge 14 about the pivot pin 15 which connects hinge and post 21 to the base 1. The spring is anchored to the base by an adjustable screw 16 which when screwed up takes the spring end to position 161 and thereby increases the tension in the spring 12. If more tension is needed in the spring to counterbalance the additional weight of the extension, then the screw can be tightened still further thus extending the spring.

Other forms of spring are envisaged such as flat bar leaf springs or compression springs. All such springs have their own characteristic adjustments and supports which might be provided with adjustment to allow for the extra load imposed by the extensions 5.

The axis of the spring lines up with the post pivot centre when the end wall is folded from the erect position to the point where the centre of gravity of the end wall.is directly over the pivot centre. In this way, extra tension created in the spring through the tightening of screw 16 does not effect the ease of folding of the posts down onto the base.

In figure 3 there is seen part of base 1 in an end elevation being the main structural side rail 18 which has recess 10 formed in it. The top lift aperture 19 of the fitting can be seen. The side rail 18 comprises top flange 24, bottom flange 20 and web 21 with recess flange 22. Because the fitting falls beside the web 21, there is no need to cut away and thus reinforce this vital part of the structure how ever long be the recess 10.

The purpose of a the platform base 1 is to carry as much cargo as it can and thus the width of the floor surface 23 extended by the top flange 24 is important. Thus a base might be made with a recess flange 22 built in longer than needed for a low height flatrack and when the posts have extensions added, the top flange 24 only need be cut away to receive the extension. Alternatively, a temporary floor component 24 ' might be provided to be removed or added when required.

However long the post 2 with extension 5, the position of the recesses 10 and top and bottom rails 9 need not be moved.

Whereas the flatrack might be made as for example with 8ft6in posts and extended at some future date to 9ft6in the converse is envisaged. A flatrack might be made at 9ft6in high and the posts cut down to 8ft6in, and there being a top fitting such as a fitting 3 or top plate 6 embedded in the structure of the 9ft6in high post this member being.redundant structurally until the other member, the extension is removed.

Similarly a 9ft6in flatrack might be made and later extended to 10ft6in, the principles being the same.

It is envisaged that in manufacture, the flatrack will be built and tested to prove its strength and operation with and without any extensions. Thus when modified in service by the addition or removal of the extensions, no substantial re-structuring of the flatrack will have been made and thus no changes to any certification issued during 6 -A " manufacture proving the safe working abilityof the flatrack would be required.

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Claims (9)

Claims

1. A platform based container with folding end walls which fold substantially into recesses formed in the base, the recesses being formed so as to receive extensions when such extensions are fixed to the top fittings without the need to substantially re-structure the said container.

2. A platform based container as in claim 1 in which the top fitting 'comprises a profiled plate.

3. A container as in claim 1 and 2 in which said extensions are fixed by welding to the top corner fittings.

4. A container as in claim 1 and 2 in which said extensions are fixed by removable means.

5. A container as in any previous claim in which the extension comprises a strut capped by a profiled top plate.

6. A container as in any previous claim in which the corner posts are counterbalanced. by adjustable springs.

7. A container as in any previous claim in which the top fitting and extension lie to one side of the web of the base side rail.

8. A container as in any previous claim in which the folded post is locked in the down position by a device engaging the post independently of the top fitting or extension.

9. A container as in any previous claim in which the structure of the post or base includes structural members which are redundant until extensions are fitted and other members cut away.