GB2361961A - A hinge for a collapsible flatrack container post - Google Patents

Abstract

A hinge for a collapsible flatrack container post comprises a stub post 10 attached to a base 1, a hinge inner 15 attached to a post 2, a pivot pin 17 and a locking key 18. The stub post 10 is capped by an L shaped fitting 11 comprising a top plate 12 and a vertical extension 13. The top plate 12 is provided with a handling aperture 16 formed through it, likewise vertical extension 13 has an aperture (14 fig. 2) formed through it to receive a lifting hook or similar (fig. 5). Hinge inner 15 passes through the aperture 16 when the post 2 is erect and is locked in the erect position with a locking key 18 abutting abutment 39 of the vertical extension 13. The L shaped fitting 11 may be forged, or of welded construction. The locking key may be rectangular, cylindrical or tapered.

Description

2361961 Title: A hinge for a collapsible flatrack -'August 4, 2000 In the

field of shipping containers there is a type of container called a collapsible flatrack comprising a rectangular platform base with erect posts normally situated at each corner though sometimes located toward the middle. The posts are attached by lockable hinges to the base so that when unlocked they fold down onto 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 At each of the eight extreme corners of the flatrack there is located a corner fitting comprising a rectangular box having formed in their three outermost walls handling apertures which are used to connect to known rail wagons, trailers, cranes and to other compatible containers including flatracks.

When the posts are folded there is a need to provide an additional top fitting with lift aperture at the extreme top corner to once again enable the handling of the flatracks by cranes and also to enable other folded flatracks to be connected to the first and thus allow handling of two or more folded flatracks as a single stacked module. Typically the additional top fitting is formed from a box type corner fitting as described earlier. one problem with such a corner fitting in this location is that as it comes under extreme load when handled, especially by slings operating at inclined angles to the vertical, or when racking on the erect posts occurs, there is not sufficient surrounding steel structure to weld it to, and to hold it in place. The result is that the welds between the corner fitting and the steel structure sometimes break.

The cost of the fitting is high. It is made by casting steel. A lower cost option would be forging but a box shape cannot be forged in one piece. Higher strength steel would be desirable but cast steel is not cheap especially when made of high tensile strength. Forgings on the other hand can be made from high strength steel with minimal cost premium.

In a known design of lockable hinge as in patent, a rectangular locking pin bears on the under side of the fitting. The under side is fitted with additional strap reinforcements to tie the fitting to the stub post steel structure yet these reinforcements get in the way of the locking pin operation trapping weld spatter and dirt. The pin ideally is close fitting and with such welded shapes tolerances are hard to maintain - it becomes important to machine the faces of the cast fitting. If the pin could bear directly on a face of the forging this would be a strength and manufacturing benefit especially since the forging can be made to close tolerances without machining. If the fitting could be attached securely without need of strap reinforcements then improvements in manufacturing and operation could be achieved.

In the present invention there is provided a hinge for a collapsible flatrack comprising a hinge inner welded to a post and a hinge outer welded to a base the inner and outer pinned together by a pivot pin the hinge outer comprising a stub post capped by a top plate the top plate having one or more extensions to over-lap part of the stub post.

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 2A and 2B there is seen a side and end elevation 2 of a hinge illustrating the prior art with the post erect, and the hinge locked.

In figure 3A and 3B there is seen a side and end elevation of a hinge incorporating one embodiment of the invention, with the post erect, the hinge locked.

In figure 4 there is seen^a hinge as in figure 3 but utilising a cylindrical pin.

In figure 5 there is seen the side elevation of the hinge in figure 4 bit with the hinge folded and lifting hook engaged in the top fitting.

In figure 1 there is seen a typical collapsible flatrack having a rectangular platform base 1, and end wall 7 comprising posts 2 at each corner, top and bottom end rails 9 and end panel 8. At the bottom of each post 2 there is a lockable hinge 4 which when unlocked allows the posts to fold down onto the base as seen in figure 1B. At each of the 8 extreme corners of the erect flatrack in figure 1A there are seen top corner fittings 3 and bottom corner fittings 33, each corner fitting comprising a rectangular box with handling apertures formed in their three outermost faces. In particular there is in the top of each fitting 3 a handling aperture 5 accessible to known lifting slings or crane spreaders fitted with twistlocks not illustrated here. When the posts 2 are folded down, the fittings 3 are displaced and handling apertures 5 must be substituted with apertures 6 provided in the top of the folded hinges 4 to enable crane or sling lifting.

In figure 2A, a known hinge 44 is illustrated in side elevation partly cut away to reveal the hinge inner 15 where mating with pin 18, and in figure 2B the same hinge in end elevation. There is a hinge inner 15 welded to post 2 and hinged via pivot pin 17 to a hinge outer 38 welded to base 1 3 forming the other half of the hinge 44. The hinge outer 38' comprises a stub post 10 with a top fitting 22 and bottom fitting 33. To lock the hinge 10, there is a rectangular section pin 18 which blocks between top fitting 22 and a heel 21 formed as part of hinge inner 15. When racked longitudinally such as experienced in normal operations where handling forces act on the top corner fitting 3 as in figure 1 illustrated by arrow R, the handling moment is resisted by the locked hinge 44 and heel 21 exerts forces up through pin 18 urging top fitting 22 away from stub post 10 resisted by poorly located largely horizontal welds along joint 23. To stop the fitting 22 being torn off, reinforcing straps 32 are added welding these between fitting 22 and the stub post 10 partly enclosing the pin 18 when locked. The enclosure is prone to collecting dirt and weld spatter making manufacture and operation difficult.

With this prior art hinge 44, it is typical to weld on straps 32 between fitting 22 and stub post 10 outboard of pin 18 to compensate for the weakness of welds along face 23. However the welding of such straps make the provision of smooth running faces for pin 18 difficult to achieve.

For a close but smooth sliding fit between pin 18 and face 24, the fitting 22 must be machined or plated with smooth faced steel. one or other of these costly methods have been used in prior art.

In figure 3A and 3B there is seen an embodiment of the invention illustrated as comparative views to those in figure 2A and 2B. A hinge 4 comprising a stub post 10 formed from welded and profiled steel plate is capped at the top with an inverted 'L, shaped fitting 11 with top plate 12 and vertical extension 13. Extension 13 has a handling aperture 14 formed through it. Top plate 12 has an aperture 16 likewise formed through it and hinge inner 15 which is welded to post 2 passes through the aperture 16 when the 4 post is erect. A pivot pin 17 and locking pin 18 complete the hinge 4.

Under handling moments imposed by handling forces discussed earlier acting on hinge 44, with heel 21 acting on pin 18 which abuts or bears directly on the underside of extension 13. Unlike top fitting 22 held by welds along face 23, stub post 10 is secured to vertical extension 13 and top plate 11 by welds along face 20 and 26 which are more advantageously located for resisting the peeling off of fitting 11. Thus no straps as 32 are needed between vertical extension 13 and stub post 10.

It is envisaged that although direct abutment of pin 18 on abutment 39 of extension 13 is advantageous abutment could be achieved via an extra component such as a screwed on shim or plate 25.

Alternatively to provide a sliding surface and abutment for pin 18, plate 25 can be cold forged as part of the extension 13 to make an accurate smooth closely toleranced face. Here is it shown slightly raised from the'body of extension 13. In figure 3A another embodiment is shown in that abutment 39 has been enlarged locally to increase the bearing surface of plate 25 where it meets pin 18 and further reinforce the extension 13 against collapse at aperture 14.

Various webs and projections 19 are formed as part of top plate 11. These serve to increase the weld attachment area between fitting 11 and stub post 10. These extensions 19 might be placed inside or outside or indeed cut through stub post 10.

Various details are seen further in figure 3 which shows the top plate 11.

Although the preferred manufacturing option is a forged top fitting 11, the top plate 12 and vertical extension 13 could be formed from steel plate and welded together during assembly or made in cast steel or as a pressed steel plate.

The rectangular section locking pin 18 might be substituted by a cylindrical or tapered pin 27 as illustrated in figure 4 passing through mating apertures formed in hinge inner 15 and stub post 10. Here the side elevation has been sectioned to reveal the hinge inner. The elongate aperture 16 and the aperture 14 are located and dimensioned to an internationally accepted standard so that all other containers complying with the standard can interface with each other and standardised handling and transport machines.

A further embodiment is seen in figure 4 in which the elongate aperture 16 has been extended further to increase the width of the hinge inner 15 to line 15'. This necessitates the thinning of closing section 28 which closes the aperture 16 and aperture 14. However to compensate for the loss of strength at this point, closing section 28 might be further extended downward by displacing end aperture 14 from its normal position to a substantially lower position at least 1Omm from the norm as illustrated by lines 141.

In figure 5 there is seen the hinge of figure 4 in a folded position and engaged with the fitting 11 is a lifting hook 29 pulled on by a wire rope 30 going to a crane not illustrated here. The lifting forces in the hook 29 urge the fitting 11 away from the stub post 10 and once again illustrate the advantages of the 'L' shape for increasing weld attachment between fitting 11 and stub post 10.

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Claims (10)

Claims

1. A hinge for a collapsible flatrack comprising a hinge inner welded to a post and a hinge outer welded to a base the inner and outer pinned together by a pivot pin the hinge outer comprising a stub post capped by a top plate the top plate having one or more extensions to over-lap part of the stub post.

2. A hinge as in claim 1 in which the top plate comprises a fitting which in side elevation appears substantially shaped as an inverted 'L' shape the vertical extension of the 'L' lapping the stub post to which it is welded.

3. A hinge as in claim 2 in which the vertical extension and top plate have handling apertures formed in them.

4. A hinge as in claim 3 in which the aperture in the top plate is open at one end to accommodate the hinge inner within it when the post is in the erect position.

5. A hinge as in claim 4 in which there are further projections extending from the top plate for weld attachment to the stub post.

6. A hinge as in any previous claim in which the underside of the vertical extension forms an abutment for a locking pin.

7. A hinge as in any previous claim in which the abutment is enlarged where it abuts the locking pin.

8. A hinge as in any previous claim in which the aperture in the top plate is elongated beyond the accepted standard size horizontally to accommodate a larger inner hinge.

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9. A hinge as in any previous claim in which the end aperture is substantially lowered from the accepted standard position.

10. A hinge as in any previous claim in which the pin is not enclosed by straps between vertical extension and stub post.

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