GB2097364A

GB2097364A - Stackable load carrying device

Info

Publication number: GB2097364A
Application number: GB8108874A
Authority: GB
Original assignee: ADAMSON CONTAINERS Ltd
Current assignee: ADAMSON CONTAINERS Ltd
Priority date: 1981-03-20
Filing date: 1981-03-20
Publication date: 1982-11-03
Also published as: GB2097364B

Abstract

A stackable load carrying device or flat in which corner posts (2) are pivotally mounted on a base (3), with each corner post having a twistlock locking means (4) coaxial with the center line of each post which is arranged to act between the base and each corner post in the axis (5) of the corner post to hold the post in an erect position; the locking means can lock onto the superimposed flat when the posts are folded and the locking means can be dropped to a load position from the locking position for the carrying device to receive the locking head of a lifting device. <IMAGE>

Description

SPECIFICATION Stackable load carrying devices The present invention relates to stackable load carrying devices known as "flats", pallets or the like.

"Flats" normally comprise a substantially plane rectangular base plate with a pivotally folding corner post at each corner. When stacked the corner posts are folded down, and in one known arrangement a locking means on a relatively lower flat is moved to lock the lower flat to a superimposed relatively upper flat. Locking means are also provided to lock each corner post in an erect position to the base of the flat when the flat is to be used.

According to one aspect of the invention a stackable load carrying device is provided with a base onto which are pivotally mounted folding posts, each post being lockable in an erect position by locking means mounted coaxially with the centre line of each post as taken in the erect position, and wherein the locking means is so arranged and positions as to lock onto an adjacent superimposed similar load carrying device.

By providing the locking means on the centre line the stress on the locking means is reduced when a post is subject to forces tending to force the post out of the erect position.

The locking means may comprise a "twinlock" carrying a pin having a somewhat elongate head which is moved upwardly into an elongate hole on a bracket. To lock the post in the erect position the pin is rotated through 900 so that the underside of the elongate head engages either side of the elongate hole to hold the bracket and then hold the post erect. A similar elongate hole is provided on the bottom of the flat (which is also used to lock the flat to a trailer) so that when locking one flat to enother in the collapsed condition, the locking means can be used to lock a superimposed flat. A problem with such an arrangement, when locking collapsed flats together, is that the round shank of the pin of the locking means may shift sideways in the elongate hole so that when the pin is turned to the unlocking position the head is misaligned with the hole and the flats can be unlocked.

According to a further aspect of the invention a stackable load carrying device is provided with a base onto which are pivotally mounted folding posts, each post being lockable in an erect position by a locking means, the underside of the device being provided with one or more holes to receive a part of the locking means to enable the locking together of superimposed carrying devices, means being provided to engage the hole to cause alignment of the locking means with the centre line of the hole.

By providing such alignment means the locking means when in the unlocked position easily releases the superimposed flat.

The alignment means preferably comprises a rotatable block or collar on the locking means which engages with a hole in the superimposed carrying device.

According to a yet further aspect of the invention a stackable load carrying device is provided with a base onto which are pivotally mounted folding posts, each post being lockable in an erect position by locking means comprising a pin with a rotatable locking head, the head being movable through a locking plate to lock onto engaging means provided on the post, the locking head being retractable in a disengaged position so as to leave a substantial gap between the head and locking plate, the provision of a substantial gap between the head and locking plate enables a lifting device with a locking means having a rotatable locking head to be inserted through the locking plate to lift the flat.

A preferred embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows diagrammatically a side view of an erected flat according to the present invention, Figure 2 shows a stack of five collapsed superimposed flats each of the sort shown in Figure 1 and each flat being locked to the adjacent flat, Figure 3 is a perspective view of a locking means on one corner post of the flat of Figure 1 with the post collapsed, Figure 4 is a perspective view of the locking means of Figure 3 with the post locked in an erect position, Figure 5 is a perspective view of part of the locking means of Figure 3 with the post collapsed and part of a top lifting device engaged for lifting the flat, Figure 6 is a detailed side view of the locking means of Figure 3 in the position shown in Figure 3, Figure 7 is a cross section taken at A-A in Figure 6, Figure 8 is a view of the head of the locking device shown in Figure 6 as viewed from B in Figure 6, Figure 9 is a detailed side view of the locking means of Figure 3 in the postion shown in Figure 4, Figure 10 is a cross section taken at B-B in Figure 9, Figure 11 is a cross section taken on C-C on Figure 9, and Figure 12 is a cross section taken on D-D on Figure 9.

In Figure 1 the flat 1 is shown in the erected condition with corner posts 2 pivotally mounted at each corner of a base 3. Each corner post 2 has a twistlock locking means hereafter called twist lock shown in broken lines which is positioned in the vertical central axis 5 of the corner post. Each post is mounted to the base by means of a bracket 6 on the upper surface of which is a locking plate 7 (see Fig. 2), the locking means 4 are each mounted within its bracket 6. Each post pivots about an axis 8 to the collapsed condition shown in Figure 2.

In Figure 2 a stack of five flats 1 are shown locked together by twistlocks 4. The upper twistlock 4 is in a retracted position to allow a substantial gap between its head and the upper surface of locking plate 7 so that a top lifting device can be inserted into and locked to plate 7.

it will be appreciated that each twistlock 4 locks into an engaging means in particular a hole 10 (see Fig. 3) in the bottom of each bracket 6. This hole 10 is used for locking the flat to a vehicle or other transporting means.

One of the brackets, posts and twistlocks will now be described in detail.

In Figures 3 to 12 the twistlock 4 will be seen to be provided with a shank 12 to which is attached at its upper end a head 13 and at its lower end a nut 14 which holds a locking arm 16 onto a square portion 18 of the shank 12. Figure 12 shows the fixture of the locking arm 16 to the square portion 1 8. Rotatable about the mid portion 20 of the shank is a sleeve 22 carrying 2 axially aligned and diametrically opposite keys 24.

The mid-portion 20 of the shank is rotatably carried in a location block or collar 26 having a wider lower portion 28 dimensioned so as to fit non-rotatably in a hole 30 in locking plate 7 and a small upper part 32 dimensioned to fit non rotatably in a hole 34 in a lower plate 36 of corner post 2.

Arm 1 6 is lockable with respect to bracket 6 in the locked position shown in Figure 9 by means of a pivotal extension member 40 which locks behind a stop 42 welded to the side of bracket 6.

The head 13 as shown in Figure 8 has a chamfered lower face 44 which when turned into the position shown in Figure 9 forces the corner post plate 36 into engagement with locking plate 7. The keys 24 co-operate with keyways 46 in an intermediate guide plate or thrust block 48 which is welded across the bracket 6 at approximately a mid-point in the height of bracket 6. In the position shown in Figure 6 the keyways 46 allow the collar to drop towards the bottom of the bracket 6 thus ensuring the head 13 drops a substantial distance X away from the bottom surface 50 of locking plate 7 thus providing a space for the locking head 62 of a lift device 60 shown in Figure 5 to lock through hole 30 onto the under surface 50 of the plate 7.

At the foot of the flat and coaxial with centre line 5 is a hole 52 which provides an engaging means for the twistlock of a lower flat or twistlock of a transporter for the flat.

Figure 5 shows the bottom portion 60 of a top lift device for lifting a flat. In order to lift the flat the corner posts 2 are collapsed, the top lift device aligned with the plate and twistlocks having heads 62 are inserted from the bottom portion 60 to engage with bracket 6 in the same or similar fashion to that described for locking the corner post 2 to the bracket 6.

In operation and starting with each twistlock in the retracted position shown in Figures 3 and 6 the corner posts 2 are first erected. At each corner arm 1 6 is rotated and the sleeve 22 with head 1 3 is lifted until the keys 24 are clear of the thrust block 48. At the same time the head 13 passes through the hole 34 in the lower plate 36 and the post and the location block 32 locates into holes 30 and 34. By this time the arm 1 6 has turned 900 from the position shown in Figure 6. The sleeve 22 is also rotated by a separate manual movement to the position shown in Figure 11. The twistlock is now held in the upper position by the keys 24 engaging on the top surface of the thrust block 38. Arm 16 is now rotated back through 900 causing the bottom face 34 of the head 1 3 to engage on the upper surface of the plate 36 of the post and to force plate 37 onto plate 7 of the bracket. The locking catch 40 is allowed to drop behind stop 42 to lock the arm 1 6 and thereby hold the head 13 in a locked position.

Claims

1. A stackable load carrying device comprising a base onto which are pivotally mounted folding posts, each post being lockable in an erect position by locking means mounted co-axially with the centre line of each post as taken in the erect position, wherein the locking means is so arranged and positioned as to lock onto an adjacent superimposed similar load carrying device.

2. A device as claimed in Claim 1 wherein the underside of the device is provided with one or more holes to receive a part of the locking means to enable the locking together of superimposed carrying devices, means being provided to engage the hole to cause alignment of the locking means with the centre line of the hole.

3. A device as claimed in Claim 1 or 2 wherein the locking means comprises a pin with a rotatable locking head, the head being movable through a locking plate to lock onto engaging means provided on the post, the locking head being retractable in a disengaged position so as to leave a substantial gap between the head and locking plate.

4. A device as claimed in Claims 1 to 3 wherein the locking means comprises a rotatable locking head having at least one radial extension the under side of which forms a bearing locking surface and wherein the corresponding post has a first elongate hole corresponding in shape to the head, the locking means and first elongate hole being so arranged that on rotation of the locking means through substantially 900 after insertion of the locking means through the first elongate hole, the bearing locking surface of the head acts on a locking surface around the first elongate hole to lock the post in the erect position.

5. A device as claimed in Claim 4 wherein a second elongate hole similarly shaped to the first elongate hole is provided in a plate surface on the bottom of the base, the first and second elongate holes being axially aligned.

6. A device as claimed in Claim 4 or 5 when dependent on Claim 2 wherein the locking means comprises a pin on which is mounted the head, the alignment means comprising a block or collar rotatable on the pin, the block or collar being dimensioned to fit non-rotatably in a superimposed said first or second elongate hole to centrally locate the head in the respective elongate hole.

7. A device as claimed in Claim 6 wherein a sleeve is mounted on the pin, the sleeve being slidable up through a thrust block mounted below the first elongate hole to a locking level, means preventing the sleeve from sliding back through the thrust block on rotation of the sleeve so as to hold the head at the locking level.

8. A device as claimed in any of Claims 1 to 7 wherein the locking means is provided with a radially extending arm by which the head of locking means may be rotated from a locking to an unlocking position and vice versa.

9. A device as claimed in Claim 8 wherein the arm has a pivotal extension member engageable with a stop to lock the arm and thence the head in a locked position.

10. A device as claimed in Claim 3 wherein the gap between the head and locking plate is at least sufficient to accommodate a further locking head below the locking plate, the further locking head being similarly shaped to the locking head of the locking means so that a lifting device fitted with the further locking head may be locked to the load carrying device.

11. A stackable load carrying device comprising a base onto which are pivotally mounted folding posts, each post being lockable in an erect position by locking means, the under side of the device being provided with one or more holes to receive a part of the locking means to enable the locking together of superimposed carrying devices, means being provided to engage the hole to cause alignment of the locking means with the centre line of the hole.

12. A stackable load carrying device comprising a base onto which are pivotally mounted folding posts, each post being lockable in an erect position by locking means, the locking means comprising a pin with a rotatable locking head, the head being movable through the locking plate to lock onto engaging means provided on the post, the locking head being retractable in a disengaged position so as to leave a substantial gap between the head and locking plate, the provision of a substantial gap between the head and locking plate enables a lifting device with a locking means having a rotatable locking head to be inserted through the locking plate to lift the flat.

13. A stackable load carrying device substantially as described with reference to the accompanying drawings.