GB2173537A - Container twistlock - Google Patents

Abstract

A corner fitting for a shipping container which comprises an aperture plate 8 and twistlock combination 13 the twistlock being pivotally attached to the aperture plate. The twistlock can be moved from a projecting operational position (Fig. 3a) to a stowed position (Fig. 3b). In the stowed position, the twistlock can be displaced about its pivot out of the corner fitting or out of the cargo zone according to handling or cargo needs. <IMAGE>

Description

SPECIFICATION Twistlock for use in freight containers This invention relates to freight containers. So called 'intermodal'freight containers are commonly used forthe transport of goods carried by rail waggons, road trailers, sea going vessels and the like.

In orderthatthese containers can be handled, stacked one upon another and lashed in position, their dimensions and strength are standardised, and at their corners they normally have standardised corner fittings into which locating, lifting and linking devices called twistlocks can engage. Typical ofthetype of cornerfitting, twistlocks and container are those described in United States Patent Specification No.

3,027,025 of March 27,1962 and others recommended by the International Organisation for Standardisation.

The cornerfittings are usually of a rectangular box shape to which structural frame members are attached. In the three outer mostfaces ofthe box are usually apertures through which handling devices can pass and in the case oftwistlocks locate and lock into the fitting.

Twistlocks are large items and are normally a seperate item from the fittings with which they mate.

But because they are seperate they can get lost yet because oftheir size they are difficu It to combine with the fittings without causing obstruction to cargo space or external handling devices orstructures.

In anothertypeoffreightcontainertwistlocksare commonly fitted to or nearthe cornerfitting butthis leads to a bulky assembly as in U.K patent 2,134,080A which can cause difficulties in manufacture or be such as to obstruct the cargo space. Obstruction of the cargo space is a particular problem in containers with folding end walls as described in U.K. patent GB 2,1 10,185A.

Accordingly the present invention provides a corner fitting with which a twistlock or locating piece may be economically stowed.

Figure 1 shows a perspective view of a typical freight container with corner fittings at each corner.

Figure 2 shows a perspective view of a typical rectangularboxcornerfitting.

Figures 3A, Band C show the side elevation in section of a cornerfitting complete with integral twisti ock with the twistlock raised, stowed and displaced by an external handling device.

Figure4shows a side elevation ofthe hinged corner of a folding container with the end wall folded which incorporates a twistlock, with part ofthe top corner fitting cut away.

Figure 5 shows the same view as figure 4 but with the corner post erected.

By way of illustration embodiments of the invention will be described.

Referring to figure 1 a typical freight container has cornerfittings 1 and 2 at each upper and lower corner connected by frame members 3,4 and having walls 5, roof 6, doors7.

In figure 2 there is a typical corner fitting 1 with handling apertures 8,9,10 in the outerfaces. It can be seen thatthefitting lisa rectangular hollow box. In dotted line a twistlockdevice 11 has entered the aperture 8 and locked inside fitting 1 so asto be able to liftthe container as in figure 1 via its upper fittings 1.

In figure 3A a corner fitting 12 similarto 1 or 2, is shown in section. Projecting through aperture 8 is a twistlock 13 which is attached pivotally to the fitting 12 via pin 14. Part of frame 3 may be seen attched to the fitting 12. The twistlock 13 may be held in the raised position by a variety of means. One method is shown whereby a projection 16 on the twistlock rests on a ledge 17 on the fitting 12 the engagement being achieved by free play in the mounting of the pin 14.

The twistlock 13 may now locate and engage with a fitting 2' shown in dotted line as part of another container.

In figure 3B, the twistlock 13 has been released from the ledge 17 and hangs freely by the pivot pin 14 under gravity. The twistlock 13 has arrived at this point either by rotation through arcA or arc B. Forthe clockwise external rotation, it will be necessaryto slot the fitting 12 at slot 1 to allowfree passage ofthe pivot arm 19 through the necesary arc A. The twistlock 13 can be seen to be obstructing the inside ofthefitting 12 directly belowthe aperture 8 and projecting into the cargo area 25 with its underside24.

In figure 3C a handling device 11 has entered the aperture 8 and pushed the twistlock 13 out of its path thetwistlock 13 having rotated about its pivot pin 14.

In figure 4 a similarviewto 3C is seen but here the fitting 12 is part of a container with folding corner posts 20 which are pivoted to a base frame 21 at pin 22 Thetwistlock 13 may operate as already described.

The post 20 has a plate 23 connected to it.

When the corner post 20 is erected to the vertical position as shown in figure Sthe post 20 passes on either side the fitting 12 butthe plate 23 engages with the underside 24 ofthetwistlock 13 causing the twistlock 13 to rotate about its pivot pin 14 into the fitting 12. The area to the right of the plate 23 is the cargo area which it can now be seen is free of the obstruction of atwistlock 13.

A plate 30 with aperture 31 is part ofthe post 20 and in the erect position sits adjacentto the top of fitting 12. The post 20 may be locked in the erect position by raising the twistlock 13 to the position 13' shown in dotted line. The twistlock 13 might wedge into the aperture 31 or be locked in the normal way into the aperture 31 or become engage in some other known way.

It is envisagedthatthetwistlock 13 may be a simple locating conewith other methods of locking containers together such as buy a bolt and hole arrangement the hole 33 being formed in the conical head 29 ofthe 'twistlock'.

It is further envisaged that in Figure 3B, if the twistlock 13 is devised to rotate through arc A, then a small projection 26 would come to rest on the corner fitting 12 and thereby supportthetwistlock 13 in the raised position. Projection 16 and 17 would notthen be necessary.

Thetwistlock 13 may be fitted with handles and other commonly used devices for its operation.

In Figure3C, if projection into the area 25 is allowable, then thetwistlock 13 might be stowed in this position by means of providingfree play in the mounting hole 27 ofthe pin 14so as to allow the twistlock 13 to drop down below a stop 28 and thereby prevent rotation about arc B until lifted past stop 28.

An advantage of movement of the twistlock 13 through arc B isthatframe member3 may preventthe externalmovementalong arcA unless cut away to accommodate such movementof the twistlock 13.

Such cutting would add costto the manufacture of the container

Claims (11)

1. Atwistlockand aperture plate combination in which the twistlock is pivotally attached to the aperture plate such that it can rotate into and out of engagementwith the aperture and having supporting means such that the twistlockcan be supported in a position projecting outthroughtheaperture in order to engages second aperture plate placed overitand such thatthe twistlock can be moved out ofthe projecting position to a stowed position partly below the aperture in which position thetwistlock, pivotally supported can be displaced out ofthe path of handling devices entering the aperture in the aperture plate.

2. Atwistlockandaperture plate combination as in claim 1 in which the twistlock inthe stowed position can also be displaced into a position underthe aperture plate and clearofthe cargo space adjacentto the aperture plate by displacement means.

3. Atwistlock and aperture plate combination as in claim 1 in which the displacement means comprises part ofthe corner post a folding container.

4. Atwistlock and aperture plate combination as in claim 1 in which the support means comprises a projection from the body ofthe twistlock which rests on partofthe aperture plate.

5. Atwistlockand aperture plate combination as in claim 1 inwhich the support means comprises at least partiallya ledge which on which thetwistlock may rest the other partofthe support being provided bythe pivotal attachment of the twistlock.

6. Atwistlock and aperture plate combination as in claim 1 in which the support means is a movable supportbrought into position underthetwistlock which support can be removed to provide a free path for handling devices entering the aperture.

7. - Atwistlock and aperture plate combination as in claim 1 in which the second aperture plate comprises part of a folding corner post such that engagement of the twistlock in the second aperture plate locks the post againstfolding.

8. Atwistlock and aperture plate combination as in claim 1 such thatwhen thetwistlock is displaced out of the stowed position by the handling device does not project above the horizontal plane in which lies the top surface ofthe aperture plate.

9. Atwistlock and aperture plate combination as described within the specification hereto or illustrated in the drawings hereto.

10. Atwistlock and aperture plate combination as in claim 1 in which the pivotal attachment comprises a pivot arm having an elongate hole formed through it rigidly attached to thetwistlock bodyand a pin fastened to the aperture plate and passing through the hole.

11. Atwistlock and aperture plate combination as in claim 10 in which the aperture plate has a slot formed through the plate at one end and in which the pin bridgestheslotsothatthe pivot arm rotates throughtheslotaboutthepin.