GB2115369A - Palletisers and depalletisers - Google Patents

Abstract

The invention relates to a palletiser or depalletiser in which a horizontally- displaceable transfer platform 10 is movable vertically between the level of a conveyor and the upper end of a pallet and is supported on a vertical frame 12 which, together with a gantry 20 is movable up and down a support column 14. The support column is arranged at only one end of the frame 12 which is thus cantilevered, the construction providing improved access to manoeuvre by a fork lift truck to remove a loaded pellet from within the palletiser and to insert empty pallets. Also where removal is via conveyor or by fork lift truck the invention allows the platform 10 to return immediately to its in feed position prior to the removal of the loaded pallet. A modification (Figure 3) includes two spaced frames (12') vertically movable on two support columns disposed on one side of a transfer platform (10') which can selectively build two stacks. The apparatus may operate as a depalletiser. <IMAGE>

Description

SPECIFICATION Palletisers and depalletisers This invention relates to palletisers and depalletisers.

Palletisers are used to stack goods of any description onto pallets and are usually provided at the output end of a conveyor in a factory to facilitate the storage of the manufactured goods in a store room.

The goods are first assembled into tiers and the palletiser stacks tier by tier on a pallet which can be removed for storage and transportation by a forklift truck.

Various forms of palletisers are known. In some forms, the goods are taken off a high level conveyor and pushed directly onto a pallet. The whole stack of goods is lowered tier by tier until the desired stack height is reached. Such a construction is normally relatively large since the whole of a stack must be lifted at a time, requiring substantial lifting equipment.

An alternative palletiser has a platform onto which the goods are transferred from the conveyor and which raises or lowers one tier of goods at a time to the prevailing stack height and transfers the tier to the stack. In this case the stack can rest on a pallet on the floor or on a low level conveyor and the platform need only support one tier at a time. The present invention is concerned with this form of pelletiser.

As earlier stated, after a stack has been built up on a pallet it is transferred either by fork lift truck or by a conveyor and a fresh wooden pallet is placed in position. Consequently, it is desirable to maximise the access, for a fork lift truck to manoeuvre a pallet load from within the palletiser and hitherto it was found that the structure of the known palletisers provided only limited access to the stacked pallets.

Where removal is via conveyor it is also desirable for the platform to immediately return to the infeeding position which is not possible before the loaded pallet has been removed with known palletisers, The present invention is concerned with the alleviation of these disadvantages.

In accordance with the present invention, there is provided a palletiser or depalletiser which comprises a horizontal platform, a vertical support frame surrounding and supporting the platform, means for raising and lowering the frame and the platform and means movable with the platform for transferring goods between the platform and a pallet wherein the means for moving the frame and the platform vertically are arranged at only one end of the frame such that the frame constitutes a cantilevered sup portforthe platform.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure lisa perspective view of a palletiser in accordance with the invention; Figure 2 is a plan view of the palletiser in Figure 1 positioned adjacent the supply conveyor; and Figure 3 is a plan view of an alternative embodiment of the invention positioned adjacent a conveyor.

Referring to Figure 1, there is shown a palletiser comprising a platform 10 which is slidably sup ported by means of a support frame 12. The frame is connected at one end to a sub-frame 42 slidable on a support column 14 which includes a motor 16 and a chain drive 18 for raising and lowering the frame 12 and the platform 10. A gantry 20 is also connected to the sub-frame 42 and consists of a rectangular tube 22 having a bar 24 supported on its upper surface and a flange 26 extending from its lower surface.

Support arms 28 secured to the platform 10 are connected to slide blocks 30 which are slidable along the bar 24 under the action of a motor 32. The arms 28 are provided with rollers which rest on the flange 26 to maintain the horizontal attitude of the platform 10.

The palletiser in Figure 1 is a free-standing structure resting on a base 34 which is generally Tshaped. The support column 14 is formed of three rectangular tubes jointed together in the form of a U-shape. The motor 16 is mounted at the top end of the column and drives a chain 18 which passes over two sprockets at the top end and the bottom end of the column 14 respectively. The chain 18 has one run, connected to the gantry 20, which is arranged between the limbs of the U-shaped column and a second run which passes down one of the tubular limbs. This construction ensures that the chain 18 is almost entirely encased to prevent accidental injury to personnel.

Rails 40 of 'U' shaped cross-section are secured to the outer surfaces of the two limbs of the column and rollers guided by the rails 40 are fitted on to the sub-frame 42 which carries the vertical frame 12 and the gantry 20.

A stripping bar 46 is secured to the ends of two arms 48 pivotably mounted at the top end of the vertical frame 12. The purpose of stripping bar is to effect the transfer of goods in conjunction with the return traverse of platform 10.

As seen in Figure 2, the palletiser is arranged adjacent a supply conveyor 50 while a stack 52 is formed on the other side of the palletiser from the conveyor.

In operation, goods which may for example be cardboard cartons arrive down the conveyor 50 and are formed into rows, either manually or automatically, adjacent the platform 10, and then transferred onto platform 10toform a completed tier. Whilst this is done, the stripping bar 46 is in its position shown in Figure 1 in which it does not interfere with the transfer of the packets. In the plan view as shown in Figure 2, the cartons being palletised are rectangular and are formed into rows and columns with the end cartons arranged at right angles to the remaining cartons. If the transversely disposed cartons are arranged alternately at opposite ends of the stack, an interlocking brickwork like pattern is formed which adds rigidity to the stack.

After a tier has been loaded onto the platform 10, the platform is lowered or raised to the top of the existing stack of pallets. This is achieved by the motor 16 driving the chain 18 which is connected to the sub frame 42 supporting the frame 12 the gantry 20 and a platform 10. On reaching the top of the stack as may be detected by suitable sensors, the motor 16 is stopped and the motor 32 is energised to displace the platform 10 to overlie the existing stack.

Subsequently, the stripping bar 46 is lowered and the platform 10 is retracted. The stripping bar prevents the return of the packets with the platform 10 thus depositing the packets at the top of the stack.

The end of the platform 10 is advantageously provided with a pivoting flap which is raised auto maticallywhen the platform is in its position illustrated in Figure 1 to prevent goods from spilling over the end of the platform and which lowers automatically during the return of the platform to ease the packets gently onto the top of the stack.

The plan view in Figure 2 shows that there may be positioned a stack 54 of pallers adjacent the palletisear to provide a new pallet each time a loaded pallet is removed. By virtue of the fact that the stack and the frame are supported on only one end, free access is provided to a forklift truck to approach from the front end of the palletiser which lies at the lower end of the plan view, as viewed.

The plan view of Figure 3 shows an alternative embodiment of the invention in which the platform 10' is supported by two vertical frames 12' which are interconnected to form a single structure. The gantry 20' in this embodiment is longer, with the intention of driving the platform 10 either to the left or to the right, as viewed in Figure 3, so as to be capable of building two stacks, one on each side of the central position of the platform. The construction and operation are in other respects similar to the embodiment previously described, the main difference being the symmetrical construction of the palletiser having two support columns, two stripping bars etc.

The lifting of the platform can be done either by means of two synchronised motors or by a single motor connected by a transmission mechanism to lifting gear in the second column.

The advantage of the embodiment in Figure 3 is that a single palletiser can be used to stack different goods thereby reducing the cost of installation of two separate palletisers. Thus though the palletiser is shown as served by only one supply conveyor it may be arranged at the end of two supply conveyors to stack the goods from different conveyors onto different stacks. Even with goods of a single description, the symmetrical construction can find application in warehouses where access by lifting trucks is required from both sides of the lifting platform.

Though the invention has been described by particular reference to a palletiser, it will be appreciated that a de-palletiser, that is to say an apparatus for placing goods from a pallet on to a conveyor operates in a generally similar manner and requires only a modification of the method of transferring goods on to and off the platform. It will be evident to those skilled in the art that the advantage offered by the cantilevered support frame in terms of improved access is equally applicable to de-palletisers.

Claims (10)

1. A palletiser or de-palletiser comprising a horizontal platform, a vertical support frame surrounding and supporting the platform, means for raising and lowering the frame and the platform and means movable with the platform for transferring goods between the platform and the pallet, wherein the means for moving the frame and the platform vertically are arranged at only one end of the frame such that the frame constitutes a cantilevered supportforthe platform.

2. A palletiser as claimed in Claim 1 wherein the meansfortransferring goods between the platform and the pallet comprises means for displacing the platform relative to the vertical frame whereby after the goods have been placed on to the platform, the platform may be displaced to overly the top of the pallet and finally the platform may be withdrawn while the goods are retained over the pallet.

3. A palletiser as claimed in Claim 2, wherein one end of the platform is provided with a pivotable flap arranged to act as an end stop while goods are loaded on to the platform and to act as a ramp when goods are transferred from the platform to the pallet.

4. A palletiser as claimed in Claim 2 or 3, in which to retain the goods over the pallet while the platform is withdrawn, a stripping bar is provided which is secured to arms pivotably supported on the upper side of the vertical frame.

5. A palletiser as claimed in any one of Claims 2 to 4, wherein the means for displacing the platform comprises a gantry which forms part of a vertically movable sub frame connected to the vertical frame, the gantry being provided with guide means for sliably guiding brackets carrying the movable platform and a motor for displacing the platform along the guide means.

6. A palletiser as claimed in Claim 5, wherein the guide means consists of a bar mounted above a rectangular tube and the platform is supported by brackets hanging from blocks slidable along the bar, the vertically depending limbs of the brackets being provided with bearings slidable along a track secured to the rectangular tube to maintain the horizontal attitude of the platform while reducing sliding friction.

7. A palletiser as claimed in any preceding Claim, wherein the sub-frame is mounted for vertical sliding movement on a single column.

8. A palletiser as claimed in Claim 7, wherein the column comprises three vetial rectangulartubes secured to one another in a U-shaped configuration, and wherein a motor is supported on the column and drives the sub-frame by means of a chain on sprockets at the upper and lower end of the column, wherein one run of the chain is arranged between the parallel limbs of the U-shaped column and is connected to the gantry while the return run of the chain is entirely encased within one of the rectangulay tubes constituting a limb of the U-shaped column.

9. A palletiser as claimed in any of Claims 1 to 6 wherein the platform is supported by two vertical frames connected to a common gantry and supported each on a respective column, the arrangement being such thatthe platform is movable from a central position between the two vertical frames to either of two positions symmetrically located lateral positions whereby to enable two stacks of pallets to be built by by the same palletiser.

10. A palletiser or a de-palletiser constructed, arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.