GB2189224A - Hinge locking mechanism for wall of collapsible flat - Google Patents

Abstract

A locking mechanism for wall of collapsible flat comprises a latch 19 mounted by a loose pivot 36,37 between plates 25 welded to plank plates 26 which mount corner post 6. The plank plates pivot at 29 to the deck 4 of the flat. The latch hooks over the edge of a stub post 28 extending upwards from the deck. The wall is prevented from outward pivoting by faces 31 of the plates 25 contacting the upper face of the stub post, when the latch is locked faces 21 and 30 of the latch and stub post respectively prevent inward pivoting of the wall. The latch is released by downward pressure on boss 22 which causes the hook part 20 to move up and out of contact with face 30 on the stub post. <IMAGE>

Description

SPECiFICATION Hinge locking mechanism improvements This invention relates to a collapsable container or so called collapsable flat having a platform for the use of transporting goods. It is common to load goods into rigid containers of a standard size, shape and strength. In the international shipping industry, the degree of standardisation covers a range of freight containers which have at each corner a special fitting which enables the containers to be handled, transported and secured by compatible standardised equipment such as trucks, rail wagons, ships and cranes, and which enables the containers to be stacked one upon another and secured to each other by securing devices.

The positioning of the corner fittings must be accurately maintained both in the unladen static state of the container, and in the dynamic and loaded condition such as when carried on board a sea going vessel in heavy seas, if the container is not to distort and become incompatible with the previously referred to handling devices and standardised equipment.

When empty of cargo, it is sometimes desirable to be able to fold the vacated container down to a fraction of its erected size, grouped with other like containers and transported back to the place where cargo is available. By this means, saving in carriage and storage may be made by virtue of the fact that the container when folded occupies less space than the erect container.

In British patent application 8404780 a latching element is disclosed which is used in the locking of a hinge used in a collapsible container. Such latches must be accurately located and tightly mounted to eliminate excessive free play in the mechanisms. Another requirement is that large bearing surfaces are needed to withstand substantial loads imposed on the latches during use of the container.

A number of problems arise from the arrangements shown in the application stemming from the use of circular section pivots to mount and locate the latch. The environment in which the containers are used is highly corrosive and dirty. Thus tight fitting pivots are highly susceptible to seizure due to dirt ingress and corrosion. Some form of lubrication can be provided but this entails the provision of expensively machined grease ways and regular maintenance and the application of grease is likely to hold dirt leading to further seizure. When damage occurs to the container and dismantling of the mechanism is needed, removal of the latch is a lengthy process since the whole hinge must be split to extract the latch pivot.

The present invention provides a means whereby the latch can be mounted without the need of lubrication, can be freed of dirt ingress, can be simply removed for repair and has a substantial bearing surface with reduced machining cost.

So that the present invention may be more readily understood and so that the features may be appreciated embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a typical collapsible container.

Figure 2 shows the side elevation of a stack of collapsed containers piled one upon another.

Figure 3 is a perspective view of some components going into the corner arrangement.

Figure 4 is a detailed side elevation of the locked hinge and locking latch cut away in part to reveal the workings.

Figure 5 is the same view as Fig. 4 but with the locking latch in the open position.

Figure 6 is a detailed side elevation of the hinge in the unlocked and folded position.

Referring to the drawings, Fig. 1 illustrates a typical collapsable container or flat. There is generally provided a loading platform 1 decked with timber flooring 2 upon which cargo may be placed and lashed. the flooring 2 is supported by structural members 3,4 an 5 which pass under the flooring 2 as indicated in broken lines. At each end of the container there is an endwall 12 comprising corner posts 6, upper transverse members 7, vertical panelling 8 and at the junction between the member 7 and the corner posts 6, a corner fitting 9. A similar corner fitting 10 is rigidly attached to the lower corners of the platform 1. Above the corner fitting 10 there is provided a corner assembly 11.

In the erected operational state as shown in Fig. 1, the endwalls 12 comprising the rigid structure 6,7,8,9 is locked by interengaging latching means within the corner assembly 11 to prevent their rotation about the pivot pins 29 in the direction of arrows 'A' down across the platform 1 and vice versa.

A number of similar collapsed containers 14, 15, 16, 17, 18 are shown in Fig. 2 stacked one upon another. The top container 14 shows, in elevation the position of the erect endwall - 12' in broken lines and the rotational direction of arrow A. It can also be seen that the lower corner fittings 10 of one container rest upon the upper part of the corner assembly 11 of a lower container.

In manufacture, the corner fitting 10 usually is welded to the stub post 28. Typically, the construction material of the corner assembly 11 and containers is a high strength steel with flooring 2 of timber or of steel.

In Fig. 3 there is seen a latch 19 having a hook 20, hook surface 21 and bosses 22 pro jecting from the body of the latch 19. The bosses 22 have planular surfaces 23 on their inward faces. As will be described in detail later when the latch 19 is mounted within the corner assembly 11, the surface 23 is supported against or near face 24 of the mounting plates 25. The relative position of the plates 25 when assembled is shown in dotted line 25'.

When assembled, the plates 25 are welded to the flank plates 26,27 and the flank plates 26,27 are pivotally mounted to the stub post 28 via pivot pin 29. The stub post 28 is rigidly fixed to the platform 2 and the flank plates 26,27 arranged to be fastened to the corner post 6.

At the top of the stub post 28 is surface 30 on to which hook surface 21 will bear in the locked position.

In Fig. 4 the assembled arrangement 11 is shown in elevation with the latch 19 in the locked position. The flank plate 27 has been cut away to reveal the internal arrangement.

When the arrangement 11 is being assembled, the latch 19 is placed on top of the stub post 28 so that the surfaces 21 and 30 are firmly in contact. The flank plates 26,27 are placed on either side of the stub post 28 and the pin 29 inserted through the flank plates 26,27 and stub post 28. Plates 25 are then placed on top of the stub post 28 so that surfaces 24 are firmly in contact with the surfaces 23 of the latch bosses 22 and under surfaces 31 are firmly in contact with the top surface 32 of the stub post 28. The plates 25 are then welded to the flank plates 26,27.

Thus in operation of the container in the erect position, any handling forces which tend to push the corner posts 6 outwards from the platform 1 are resisted by the pivot pin 29 and the plates 25 whose under surface 31 is supported by the top surface 31 of the stub post 28. Handling forces which tend to push the corner post 6 towards the platform 2 are resisted by the pin 29 and the plates 25 whose surface 24 is supported by surface 23 of the latch 19, itself caught by hook 20 whose surface 21 is supported by surface 30 of the stub post 28.

In Fig. 5, the latch 19 has been released from engagement with the stub post 28. The hook 20 has been lifted causing the boss 22 to pivot about radius 33. It can be seen that surface 23 has parted from surface 24. Radius 33 may rest directly in surface 32 of the stub post. If the radius 33 is small or even a sharp point very little frictional resistance can be generated to oppose the rotation of the latch 19. If the radius 33 is larger, a roiling motion along the top surface 32 of the stub post 28 may take place during rotation of the latch 19 again causing no frictional resistance. No pivotal mounting of the radius 33 is required.

Alternatively the latch 19 may be retained loosely by a support 34 fixed across the flank plates 26,27 which supports the latch against upward or downward movement at the end near the bosses 22 and also prevents the latch 19 from being removed. The rotation of the latch 19 on the support 34 will be as described above when supported on the stub post 28.

Since the surfaces 23,24 part from one another, any dirt, corrosion, or friction on or between the surfaces will have little affect in preventing the latch 19 from being released from the stub post 28.

Furthermore, since the surfaces 23,24 are parted, any dirt between them might be easily cleaned out. By removing the support 34, the latch 19 can be lifted out from the plates 25 for repair or replacement.

Returning to Fig. 4, the surfaces 23,24 can be seen to be inclined to the vertical by angle B. The choice of angle B can have an influence on the working of the arrangement.

When handling forces act on the locked and erect corner post the flank plates 26,27 and plates 25 tend to move in a direction tangential to a radius 35 passing through the pivot pin 29. If the angle B is on a radial line passing through the pivot pin 29 and the hook 20 can be considered to be pin jointed to the stub post 28, then there will be little tendancy for the surface 23 to move over the surface 24. If the angle B is inclined one way or the other, because of the resolution of the loadings falling on the surfaces 23,24, there will be a bias upwards or downwards according to the angle B.

The angle B is here selected to be inclined towards the vertical than to the radial line 35 so that the resolution of the loading forces which might cause slippage between the surface 23,24 will move the bosses 22 downwards into firmer engagement with the support surfaces 24 and 30 in a wedging action.

It is envisiaged that mounting of any similar latch or hook can be as described to allow the advantages as described. More accurate location of the latch 19 during its operation can be achieved by closer control of the clearances between the support 34 and the bosses 22.

It can be seen that under load when the latch 19 is locked to the stub post 28 and flank plates 26,27, no load of any substance passes through the pivotai radius 33, the load being spread over the surfaces 23,24,21,30.

It is envisiaged therefore that a small pivot arrangement could be located away from the bosses 22 at some point such as pin 36 and by selection of suitable geometry such as clearance between surface 32 and the underside of latch 19, the pivot could be used for operation only and play no major part in the load resistance. The pin 36 might be mounted in the plates 25 with large diameter holes 37 with clearances to overcome corrosion problems.

Claims (10)

1. A latch for locking the hinge assemblies of a collapsible container comprising walls pivotally mounted on a base such that the walls may be folded down onto the base or raised up from the base into an erect position and there prevented from folding out further by supporting contact being made between bearing plates suitably fixed to the rotating wall and a surface of part of the base and there being prevented from folding inwards to the base by said latch which links the wall to the stub post the latch having a hook at one end and projecting bosses at the other end, the hook being engaged to a mating surface on the stub post and the bosses being supported by said bearing plates 25 and such that when the latch is released by freeing the hook from the stub post the latch is free to move away from the bearing plates 25

2.A latch as in claim 1 in which the bosses have a plane surface which come to rest on plane surfaces of the bearing plates when the latch is locked.

3. A latch as in claim 1 or 2 in which a the hook end is being released the bosses move out of engagement with the bearing plates.

4. A latch as in any previous claim which is prevented from being removed when released by a loose fitting support.

5. A latch as in any of the previous claims which is released by rotation about a fulcrum which is close to one end of the bearing surface of the bosses.

6. A latch in any of the claims 1, 2, 3 or 4 in which the plane in which the bearing surfaces of the bosses lie is angled to the plane in which the hook bearing surface lies such that the latch may be released by movement of either or both ends towards the apex of the planes.

7. A latch as in any of the previous claims in which the mounting is reversed so that the hook end engages with the wall and the bosses bear on additional plates fixed to the base.

8. A latch as in any of the claims 1,2,3,4,5,6 which is carried with the wall.

9. A latch as in claim 7 where it is mounted on the base.

10. A latch in any of the previous claims in which the bosses comprise a hook end.