GB2261259A

GB2261259A - Hinge for a collapsible container

Info

Publication number: GB2261259A
Application number: GB9223553A
Authority: GB
Inventors: Martin Clive-Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-11-08
Filing date: 1992-11-09
Publication date: 1993-05-12
Also published as: GB9223553D0

Abstract

A platform based container 1 with folding posts 6 known as a collapsible flat rack has lockable hinges 11, the locking means comprising a locking pin 21 which slides in and out of engagement with the hinge assembly 11 urged on by a sliding hammer 29, the pin 21 being protected by a grease tube 23 adjacent to the hinge assembly. The pin inter-engages post hinge plates 25 and base hinge plates 24 through holes 25, 26 which are in alignment when the post 6 is erect. Catch plate 34 locates between abutment plates 31, 32 and the hammer to hold the pin in either its locked or unlocked position. <IMAGE>

Description

Title: HINGE FOR A COLLAPSIBLE CONTAINER In the field of shipping containers there is a type of special container called a collapsible flatrack which comprises a horizontal platform base with vertical posts normally at each corner. One type of flatrack is collapsible wherein the corner posts are pivotally attached to the base. They can either be locked in the vertical position or the corner posts can be unlocked and collapsed down to the base. Once collapsed the flatrack can be used as a simple platform cargo carrier or other collapsed flatracks can be stacked upon it to enable economical storage and transport.

When the posts are erect, substantial handling forces can be exerted to the top of the posts in any direction during sea and land transport. The geometry of the posts must remain firm to ensure that other similar containers can be stacked and supported on top of the posts. Thus it is important that the posts held rigidly in place, resist the handling forces experienced during operation and be relatively free of natural play in the mechanism. These requirements result in magnified forces being transmitted down into the post hinges and locking devices.

The conventional solution to the problems of restricting post movement and ensuring strength of attachment of the post to the base is to provide tight fitting locking devices and close fitting hinges and abutments. But because the forces can act in any direction, the fitting of the locking devices, hinges and abutments is difficult to achieve. The forces being large necessitate large heavy locking devices.

According to the present invention there is provided a collapsible flatrack comprising a platform base with posts pivotally attached to the base by hinges able to be locked which when locked hold the posts in the erect position and when unlocked to allow the posts to be collapsed down to the base, the hinge comprising post hinge plates and base hinge plates through which passes a pivot pin and the locking means comprising a locking pin which passes through cooperating holes formed in the base hinge plates and post hinge plates the locking pin being extended substantially outside the hinge assembly by a shaft on which is mounted a hammer which is mounted so as to slide along the shaft meeting at either end of its travel an abutment plate such that impact of the hammer with one or other of the abutment plate urges the locking pin to slide in or out of engagement with the base and post hinge plates.

A preferred embodiment of the invention will now be described with reference to the following drawings in which: Figure 1 shows a perspective view of a collapsible flatrack container.

Figure 2 shows a side elevation of a stack of collapsed flatracks.

Figure 3 there can be seen a detailed side elevation view of the lower corner arrangement with the post erect.

Figure 4 shows the rear elevation of a lower corner with the post erect.

Figure 5 shows the same as Figure 3 with the post folded to the base with a second flatrack being lowered onto the lower of the two.

Figure 6 shows a plan view on the lower corner with the post erect but removed.

Figure 7 shows the same view as figure 4 cut away to show interior details.

In figure 1 there is seen a typical collapsible flatrack comprising a base 1 with floor 2, end rails 3 and side rails 4, and a wall 8 at each end with posts 6, top rail 7 and bottom rail 12. At each corner of the flatrack is a box 9, 10 which has in it apertures 5 formed to accept known hooks and twistlocks. The walls 8 are locked in the erect position shown by the hinge assembly 11 which when released allows the walls 8 to fold down onto the base 1 about arrows 'A'.

Typically the materials of construction of the flatrack are a high strength welded steel with a floor of timber.

In figure 2 a number of similar flatracks 14,15,16,17,18 can be seen folded and stacked one upon another.

In figure 3 the post 6 is erect. The post 6 is connected to post hinge plates 22 and the base 1 through side rails 4 is connected to base hinge plates 24. A pivot pin 23 passes through base hinge plates 24 and post hinge plates 22 thereby attaching posts 6 pivotally to the base 1. The back of post hinge plate 22 can be seen to abut aperture plate 19 at face 45 preventing the post 6 from falling outboard from base 1. Thus any forces acting as in figure 1 in the direction of arrow C on the top box 9 will be supported by reactions in the aperture plate 19 through to base 1 via base hinge plates 24, and by reaction in pin 23 through to base hinge plates 24 and base 1.

The pin 21 can be seen passed through holes 25 and 26 formed in plates 22 and 24 respectively, the holes 25, 26 being aligned when the post 6 is erect and locked.

In figure 4 the locking pin 21 is exposed by the sectioning of base and post hinge plates 22, 25. In this embodiment there are two post hinge plates 22 and three base hinge plates 24 so that the locking pin 21 has a number of shear paths, four in this figure, when in the locked position as shown. The greater the number of shear paths, the more force can be supported by a given size of pin. Thus the diameter of pin 21 can be made relatively small compared to pivot pin 23 which has only two shear paths to support in effect the same operating loads.

In practice it is found that the smaller the diameter of the pin 21, the lower the jamming forces set up by misalignment of holes 25, 26, dirt and corrosion getting onto the holes 25, 26 and pin 21. A smaller pin 21 is also lower in mass making it easier to hammer in and out of holes 25, 26 and cheaper to manufacture.

The pin 21 extends beyond the hinge assembly 11 by shaft 28 which can comprise and extension of pin 21 or be an additional item fixed to pin 21. A hollow cylindrical hammer 29 shaped here in profile as a dumbbell is mounted on the shaft 28 such that it can slide up and down the shaft 28. The shaft 28 passes through a clearance hole (not shown) in bracket 30 allowing it to slide horizontally. Two abutment plates 31, 32 are welded to shaft 28.

To release the locking pin 21 from engagement with the hinge assembly 11, the hammer 29 is slid by hand along the shaft 28 until it impacts stop 32. This impact causes the locking pin 21 to withdraw from holes 25, 26. With locking pin 21 withdrawn, the plates 22 and post 6 can rotate about pin 23 and thus post 6 can be folded down onto the base 1 in the arc direction of arrows A in figure 1.

Locking the locking pin 21 through holes 25, 26 is carried out by impact by hammer 29 on abutment plate 31. The pin 21 has a tapered nose 38 which moves from unlocked position denoted by 38' to the position shown in figure 4 at 38. The tapered nose 38 forces the plates 22, 4 and their holes 25, 26 into alignment and in doing so takes up any clearances in the hinge assembly 11.

Adjacent to the hinge assembly 11 is seen a tube 33 which is attached to hinge assembly 11. The tube 33 is filled via known means such as a grease nipple not illustrated with lubricant such as grease and so that as the pin 21 slides through tube 33, the pin surface becomes lubricated to ease sliding within the hinge assembly 11. The pin 21 is protected from corrosion and damage in both the locked position (nose at 38) and the unlocked position (nose at 38') by being contained substantially within the hinge assembly 11 or tube 33.

The tube 33 acts also as a stop to abutment plate 31 which presents the pin 21 from passing too far out through the hinge assembly 11 in the locked position. It is an advantage for nose 38 to project through the hinge assembly 11 as seen so that should the pin 21 become difficult to withdraw, the nose 38 might be urged inwards by contact with it from outside the hinge assembly 11.

To keep the pin 21 in the locked position (nose at 38) there is a catch plate 34 (cut away but denoted by line 34') which is attached by pivot 39 to the base 1, and which drops down beside hammer 29.

Hammer 29 abuts abutment plate 31 and cannot slide along shaft 28, thus retaining pin 21 cannot withdraw from hinge assembly 11.

Similarly when the hammer 29 is withdrawn to 29' with abutment plate 32 to 32', the pin 21 cannot engage with the hinge assembly 11 when catch 34 is down at 34'.

A twistlock 35 is shown here in the stowed position. When the post 6 is folded out of the way the twistlock 35 which is connected adjacent to aperture plate 19 by a bracket 40 fixed to the twistlock 35 and pivoted to aperture plate 19 by pin 41 which enables the twistlock to be raised through an arc up on top of aperture plate 19 to a position shown in figure 5.

In figure 5, the post 6 can be seen collapsed down to the base 1.

Two flatracks 14 and 15 are illustrated with flatrack 14 in the process of being lowered down onto flatrack 15. The twistlock 35 is raised with its tapered head 42 ready to guide and enter into box 10 above. Base hinge plate 24 of flatrack 15 is cut away to show another base hinge plate 24' located inside the hinge assembly 11.

Post hinge plate 22 is seen to be extended by plates 43, 43' through which holes 25 are formed. Plates 43, 43' are welded to post hinge plate 22.

Figure 6 shows the hinge assembly 11 in plan view with the post 6 removed and a section through the post hinge plate 22 seen. It can be seen that the post hinge plate 22 in this erect position passes through the aperture plate 19. The elongate shaped aperture 44 in aperture plate 19 is closed at one end at face 45. The closure at face 45 is needed to retain the twistlock 45 when located in the aperture 44 and to restrain movement of any other twistlock or other handling device making use of the aperture 44 for handling the flatrack 14. The face 45 is in one plane with the top surface of the aperture plate 19. However formed in the surface of aperture plate 19 is a recess 46 which receives the bracket 40 of twistlock 45 when twistlock 45 is in the projecting position seen in figure 5.

Since the corner posts 6 and walls 8 are too heavy for manual erection, a counterbalance spring 36 shown mostly in dotted line in figure 3 is connected to spring plate 37. The spring plate 37 is fixed to the pivot pin 23 and the pin 23 is fixed against rotation within the post hinge plate by a cotter pin 47 which passes through both pin 23 and post hinge plate 22. The spring plate 37 is pivotally attached to a drive assembly 48 which itself passes through the centre of spring 36 through a hole in bracket 49, the bracket 49 being fixed to side rail 4. As the post 6 is folded down, the pivot pin 23 rotates causing spring plate 37 to displace drive assembly 48 thereby compressing spring 37 between plate 50 fixed to drive assembly 48 and bracket 49. The resulting compression in spring 36 counterbalances the gravitational pull of the post 6 urging the post 6 towards the erect position.

Figure 7 shows the same view as figure 4 but with closer detail of the interior of hinge assembly 11. Plate 24' is seen fixed to box 10. Post hinge plate 22 can be seen to be extended by two plates 43 and 43'. It is the plates 43, 43' in this embodiment which have the holes 25 formed in them. There are seen working clearances between plates 24, 24' and plates 43, 43'. The aperture plate 19 has been cut away to reveal the aperture 44 through which plate 22 passes. It can be seen that the assembly width across plate 43 to plate 43' is wider than the width of aperture 44. The geometry of the folding of post 6 is such that the plates 43, 43' rotate about pivot pin 23 but keep below the underside of aperture plate 19. In this way, the four shear paths through pin 21 denoted S, T, U, V can be achieved without having to make use of impractically thin plates for plates 43, 43, 24'.

In another arrangement, plate 24' might be removed and plate 22 extended down towards box 10 in order that the holes 25 might be formed directly through plate 22.

Spring 36 might be arranged as a compression spring as illustrated or re-mounted with end retainers to be a tension spring.

The mounting of the twistlock 45, its bracket 40 and the recess 46 are known methods of retaining the twistlock 45 to the base 1.

Alternatively, as in figure 6, the bracket 40 might be re-shaped, and the pivot pin 41 and twistlock stowage repositioned so that the bracket 40 can move through the inner most opening 51 of aperture 44.

In this way, the recess 46 would not be needed.

It is envisaged that the pin 21 might be moved in an out of engagement by means other than use of a hammer 29. The tube 33 is useful but might be omitted.

wp22 CP3-SPC

Claims

CLAIMS 1. A collapsible flatrack comprising a platform base with posts pivotally attached to the base by hinges able to be locked which when locked hold the posts in the erect position and when unlocked to allow the posts to be collapsed down to the base, the hinge comprising post hinge plates and base hinge plates through which passes a pivot pin and the locking means comprising a locking pin which passes through cooperating holes formed in the base hinge plates and post hinge plates the locking pin being extended substantially outside the hinge assembly by a shaft on which is mounted a hammer which is mounted so as to slide along the shaft meeting at either end of its travel an abutment plate such that impact of the hammer with one or other of the abutment plate urges the locking pin to slide in or out of engagement with the base and post hinge plates.
2. A collapsible flatrack as in claim 1 in which there are more than 2 shear paths through the locking pin when it is in the locked position.
3. A collapsible flatrack as in claim 1 and 2 in which the shaft is concentric with the locking pin.
4. A collapsible flatrack as in claim 3 in which the shaft is formed as one component with the locking pin.
5. A collapsible flatrack as in claim 1, 2, 3 and 4 in which there is a tube mounted adjacent to the hinge assembly through which the locking pin passes the locking pin being at least partly housed within the tube when in the unlocked position.
6. A collapsible flatrack as in claims 1 to 5 in which the pivot pin is fixed to and rotates with the post hinge plates and is extended outside the body of the hinge to drive a counterbalance spring.
7. A collapsible flatrack as in claim 6 in which the counterbalance spring comprises a compression spring.
8. A collapsible flatrack as in claims 1 to 7 in which there is a twistlock mounted adjacent the hinge assembly for pivotal movement into and out of the aperture plate.