GB1596789A

GB1596789A - Depalletisers and palletisers

Info

Publication number: GB1596789A
Application number: GB2769077A
Authority: GB
Original assignee: Depallorator Corp Ltd
Current assignee: Depallorator Corp Ltd
Priority date: 1977-07-01
Filing date: 1977-07-01
Publication date: 1981-08-26
Also published as: CA1088117A

Description

(54) IMPROVEMENTS IN OR RELATING TO DEPALLETISERS AND PALLETISERS (71) We, DEPALLORATOR CORPORATION LIMITED, of 37-39 Fitzwilliam Square, Dublin 2, Republic of Ireland, an Irish company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a depalletiser, that is to say a machine for unloading tiers of goods from a pallet onto a take-off surface. It also relates to a palletiser which loads tiers of goods onto a pallet from a take off surface.

In British Patent Specification No.

1494832, there is described a depalletiser for unloading tiers of goods from a pallet onto a take-off surface which comprises a vertically movable horizontal platform, lifting means for vertically aligning the platform sequentially with the uppermost tier and with the take-off surface and transfer means movable with the platform for transferring the goods of the uppermost tier from the pallet to the platform when the platform is aligned with the tier and from the platform to the take-off surface when the platform is aligned with the take-off surface.

The above patent application also teaches the provision of means for steadying the tier of goods immediately below the uppermost tier so as to steady the pallet during transfer of the uppermost tier. It is necessary to steady the pallet as the goods are being transferred in order to prevent the whole pallet from being upset. The means for steadying the tier of goods immediately below the uppermost tier comprise a pair of plates attached to the platform and movable laterally to steady the next-to-uppermost tier.

A problem encountered with the apparatus described in the above application resides in the fact that the plates for steadying the next-to-uppermost tier constituted an obstruction preventing the table from being lowered down to ground level, so that it was not possible to support a pallet directly on the ground and transfer the goods from the lowermost tier onto the table.

With a view to mitigating the disadvantage in the machine described in British Patent Specification No. 1494832, in accordance with the present invention, the plates for locating about the next-touppermost tier are movable vertically relative to the platform. This may either be achieved by arranging the gripping plates to be pivotable about a horizontal axis upon reaching a lowermost position or by mounting them for sliding movement relative to the platform.

In the above patent Specification, when the platform onto which the goods are transferred from the pallet is brought into alignment with a take-off surface, a flap is lowered in order to bridge the gap between the platform and the take-off surface. A further bridge was provided between the pallet and the platform. This entailed accurate positioning of the pallet in relation to the platform in order for smooth transfer to be achieved.

Such a bridge between the pallet and the platform may be provided in embodiments of the present invention, but in order to overcome the above disadvantage, in accordance with a preferred embodiment of the present invention, the platform is movable not only vertically for alignment with the respective tiers of a pallet but also horizontally in order to bring the platform into engagement with the respective tiers and subsequently into alignment with the take-off surface.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of a depalletiser in accordance with the invention Figure 2 is an end elevation of the depalletiser in Figure 1, and Figure 3 is a plan view.

In the drawings, there is shown a depalletiser generally designated 10 which removes successive tiers 12, 14, etc. from a pallet 16 and transfers them to a take-off surface which in practice may be the conveyor belt of a factory line or an accumulating table, but is shown in Figure 1 as a small fixed transfer platform 18 at the required height.

The depalletiser includes a table or platform 20 which is mounted on a subframe generally designated 22. The subframe 22 is movable vertically on a pair of columns 24 by means of a motor 26 which is connected to the subframe 22 by means of a suitable transmission. For example, the subframe 22 may be raised and lowered by means of a chain powered by the motor 26 or a screw jack serving to drive the subframe 22 vertically may be driven by the motor 26.

The platform 20 is itself movable horizontally relative to the subframe 22, the horizontal movement being achieved by means of a hydraulic jack 32 shown in Figure 3.

A transfer mechanism generally designated 40 is provided for transferring goods from the pallet onto the platform 20 and subsequently from the platform 20 onto the take-off surface. The transfer mechanism comprises a sweep arm 42 which is supported by means of a strut 28 and bearings 30 on a horizontal rail 44 which is movable with the subframe 22. The sweep arm 42 is driven by a chain mechanism not shown in detail which is in turn powered by an electric motor 46 supported on the rail 44.

An arm 48 for steadying a tier of goods during its transfer is mounted an an adjustable telescopically collapsible extension 50 for movement with the sweep arm 42. When transferring tall bottles, or the like, the arm 48 serves to prevent the row of bottles at the front end of a tier from toppling whilst it is being advanced by means of the sweep arm 42.

In order to steady the next-to-uppermost tier 14 whilst goods from the uppermost tier 12 are being transferred onto the platform 20, plates 60 are arranged on each side of the pallet 16 and are movable laterally, to grip the pallet, by means of arms 62 which are connected to a hydraulic jack (not shown) arranged beneath the platform 20.

The plates 60 are pivotable mounted by means of a universal joint 64 for movement in and out of the plane of the drawing of Figure 1 to grip the pallet 16 and they are additionally pivotable at the joint 64 about an axis perpendicular to the plane of Figure 1, the plates adopting the position illustrated in Figure 1 by virtue of their own weight. The joints between the plates 60 and the arms 62 which serve to move the plates laterally are also designed to permit vertical movement of the plate 60.

In operation of the machine shown in the drawings a pallet 16 is placed into position.

The height of the subframe 22 is then adjusted by operation of the motor 26 until the platform 20 is level with the bottom of the uppermost tier 12. This position can either be determined by means of an operator on hand or automatically if sensors are provided, in a conventional manner, to detect the level of the uppermost tier. The plates 60 are moved towards one another by operation of the jack connected to the plates 60 via the arms 62, so that the arms 60 move laterally and grip the sides of the pallet. The platform 20 is at some stage moved horizontally to close any gap between itself and the uppermost tier 12.

When the platform is correctly positioned and the pallet 16 suitably steadied by the plates 60, the sweep arm 42 moves from left to right as viewed in Figure 1 to sweep the goods on the uppermost tier onto the platform 20. The space between the sweep arm 42 and the steadying arm 48 is adjusted by means of the telescopically collapsible tube 50 so that during this transfer the arm 48 serves to steady the front row of articles being transferred.

When all the goods of the uppermost tier are arranged on the platform 20, the plates 60 release the pallet 16 and the platform is moved away from the pallet and is lowered to align with the smaller platform 18. The platform 20 is again moved horizontally to contact the platform 18 and finally the sweep arm 42 continues its sweep to transfer the goods from the platform 20 onto the take-off surface.

The above set of operations is repeated to transfer the next-to-uppermost tier, and so on until the lowermost tier is reached.

When transferring goods of the lowermost tier onto the platform 20, during the descent of the platform 20 a microswitch is operated in a lowermost position of the platform 20 which operates a servomotor, preferably a pneumatic motor, to cause the plates to pivot about the joints 64 and not therefore impede the descent of the platform 20. It will be noted that the plates 60 have an inclined lower edge and this is so that this edge should lie just above and parallel to the floor when the platform 20 attains its lowermost position.

Whilst the invention has been described with reference to a depalletiser, it should be appreciated that a palletiser embodying the invention would be similar to the above described embodiment, needing only a few different features to enable leading to be effected.

Claims

WHAT WE CLAIM IS:

1. A depalletiser for unloading tiers of goods from a pallet onto a take-off surface, comprising a vertically movable horizontal platform, lifting means for vertically aligning the platform sequentially with the uppermost tier and with the take-off surface, and transfer means movable with the platform for transferring the uppermost tier of goods from the pallet to the platform when the platform is aligned with the tier and from the platform to the take-off surface when the platform is aligned with the take-off surface, wherein a pair of opposed plates attached to the platform and movable laterally towards one another to grip the next-to-uppermost tier are provided to steady the pallet during transfer of the uppermost tier of goods, the said plates being further movable vertically relative to the platform.

2. A depalletiser as claimed in Claim 1, wherein a flap is provided for bridging the gap between the pallet and the platform.

3. A depalletiser as claimed in Claim 1, wherein the platform is horizontally movable whereby to close any gap between the platform and the pallet and any gap between the platform and the take-off surface.

4. A depalletiser as claimed in Claim 1, 2 or 3, in which the said plates are carried on arms pivotable about a horizontal axis so as to be vertically movable with respect to the platform.

5. A depalletiser as claimed in Claim 4, in which a micro-switch is provided operative to energize a servo-motor for pivoting the said plates about said axis when the platform approaches its lowermost position.

6. A depalletiser as claimed in any preceding claim, wherein the transfer means comprises a continuous chain and a sweep arm extending transversely across the platform.

7. A depalletiser as claimed in Claim 6, wherein a further arm is provided movable with the said sweep arm to steady the foremost row of goods in each tier being transferred by the transfer means.

8. A depalletiser as claimed in Claim 7, wherein the steadying arm is connected to the sweep arm by means of a telescopically collapsible support so as to enable the distance between the two arms to be varied.

9. A depalletiser as claimed in any preceding claim, wherein the platform is secured on one side only to a sub4rame in a manner to be horizontally movable relative to the sub-frame, the said sub-frame being mounted for vertical movement on a support column.

10. A palletiser for loading tiers of goods onto a pallet from a supply surface, comprising a vertically movable horizontal platform, lifting means for vertically aligning the platform sequentially with the supply surface and with the uppermost tier of the pallet and transfer means movable with the platform for transferring a tier of goods onto the top of the uppermost tier pallet from the platform when the platform is aligned with the uppermost tier and onto the platform from the supply surface when the platform is aligned with the supply surface, wherein a pair of opposed plates attached to the platform and movable laterally towards one another to grip the uppermost tier are provided to steady the pallet during transfer of a tier of goods onto the top of the uppermost tier of goods, the said plates being further movable vertically relative to the platform.

11. A palletiser or a depalletiser constructed substantially as hereinbefore particularly described with reference to and as illustrated in the accompanying drawings.