GB2134066A - Stacking apparatus - Google Patents

Abstract

Stacking apparatus, e.g. for loading pallets 14 with prefilled sacks or other articles, includes an overhead carrier 21 having an openable floor 23 and which is movable in lateral and longitudinal directions and also rotatable about a vertical axis whereby the article may be positioned anywhere over the area of the pallet and also turned to give it the desired orientation relative to other articles already deposited. To enable successive layers of articles to be built up the pallet may be progressively lowered on a lift 17 operated by hoist mechanism (16) relative to the carrier. <IMAGE>

Description

SPECIFICATION Stacking apparatus This invention relates to apparatus for stacking articles in a regular manner with particular, but not exclusive, reference to the loading of pallets with pre-filled sacks containing such loose material as solid fuel or with a number of other discrete articles such as packing cases, bundles, bales, containers, blocks or the like.

Pallets are increasingly employed in the distribution of a wide range of goods to their point of sale, local distribution, or consumption to reduce transport costs and avoid manhandling of the individual articles and this involves the consistent and secure loading of each pallet with a regular stack of the articles, the object of the invention being to provide stacking apparatus which is particularly suited for this purpose, which will operate automatically or semi-automatically, which is of simple construction and reliable and economical in operation and which avoids the need for any manhandling of individual sacks or other articles being stacked or of the completed stack or of the pallets if these are used.

According to the invention there is provided stacking apparatus including distributing means for successively positioning a series of substantially uniform articles on a support to form a stack in successive layers superimposed on each other and with each layer comprising a plurality of the articles in a prearranged relationship with each other and with any preceding layer; said distributing means including a carrier adapted to receive an article from a supply in use and movable both longitudinally and laterally of the stacking area, means for selectively releasing the article from the carrier at a predetermined location in said area, and means providing relative vertical movement between the distributing means and the area of the stack for the building of successive layers.

Preferably the carrier can also be rotated about a vertical axis for turning any article to a desired orientation in a horizontal plane with respect to other articles previously deposited.

Conveniently the apparatus includes supporting means operatively carrying an upper surface, e.g.

of a pallet, comprising the area on which the stack is formed, said supporting means being operatively progressively lowered relative to the distributing means for the formation of the successive layers.

The carrier may take the form of a cage having a side opening to receive an article from the supply and a floor structure which can be opened to reiease the article for deposit on the stack, for example a divided floor and end walls which can be opened pivotally in the manner of a clam-shell bucket.

One embodiment of the invention is now more particularly described with reference to the accompanying drawing, wherein: Figure 1 is a side elevation of stacking apparatus; Figure 2 is a part sectional plan view on line 2-2 of Figure 1; Figure 3 is an end elevation of an upper portion of the apparatus; Figure 4 is an end view of a carrier of the apparatus when closed; Figure 5 is a like view showing the carrier open; and Figure 6 is a diagram of a stack of sacks in course of formation on a pallet.

The apparatus described is primarily for stacking filled sacks, e.g. prepacked and preweighed paper sacks of solid fuel onto standard pallets for subsequent bulk transport to distribution points.

The apparatus comprises a fixed vertical framework 10 whose upper part locates automatic distributing means 11 for handling and positioning each sack and whose lower part locates pallet handling and support means 1 2.

The latter comprises a lower feed path consisting of a series of transverse rollers 1 3 along which pallets 1 4 are fed successively from a magazine (not shown).

A pallet lift 1 5 can be raised and lowered in a central area of framework 10 by a counterweighted hoist mechanism 1 6 and includes a series of transverse bars 1 7 which, with the lift at its iowermost position, pass between a series of the rollers 1 3 so that an empty pallet can be pushed above them. Support means 12 includes an automatic centering device (not shown) to accurately position each pallet relative to the lift bars 17.

The distributing means 11 includes an overhead track 20 on which runs a downwardly depending carrier 21 described in greater detail hereafter. Track 20 is arranged so that the carrier can be traversed both longitudinally and laterally (i.e. on x and y axes) in a horizontal plane above the area occupied by the pallet 14 which is positioned for loading. As well as these traversing movements in a horizontal plane, carrier 21 can also be rotated about a vertical axis at any position within its range of travel as it hangs from a vertical pivot 22.

The lowest part of carrier 21 is in the form of a basket 23 shown in detail in Figures 4 and 5 having a floor formed in two halves, 24a, 24b from freely rotatable rollers pivoted on a pair of end frames 25a, 256. The upper parts of these frames have toothed arcuate peripheries which are meshed together so that, by selective operation of an actuator (e.g. a hydraulic ram) (not shown) the two halves may be opened in the manner of a clam-shell bucket to the position shown in Figure 5.

When the floor of basket 23 is closed the two end frames 25a define a side opening for receiving a sack 30 (various sizes of sack are indicated diagrammatically in Figure 4) from an upper feed path shown in Figure 3 comprising a belt or other conveyor 35 leading, for example, from an automatic sack filling and weighing station (not shown) and terminating in a downwardly sloping set of rollers 36 on framework 10 with which the floor of basket 23 is aligned to receive a sack. The floor 24b of the basket on the opposite side to the opening is curved upwards to halt the sack when it is rolled into the empty basket.

The operation of the apparatus will now be further described. Depending on the nature and shape of the articles being handled (which may be other than the sacks referred to above) a stacking pattern and sequence will have been predetermined and automatic control means of the apparatus will have been preset accordingly.

For example the range of traversing movement of the carrier 21 is determined by limit switches on the x and y axes.

Lift 1 5 operates automatically to raise the empty pallet 14 which is next to be stacked to an uppermost position shown in broken lines in Figure 1 at which its upper surface is spaced a short distance below the basket floor. Carrier 21 is positioned to receive the first sack from rollers 36 and is then traversed and, if need be, rotated automatically until it is above and correctly orientated with respect to the desired position on the pallet. The basket is then automatically opened to deposit that sack correctly, following which it is closed and returned to receive the next sack for positioning, e.g. alongside the first.

When the first layer has been completed lift 1 5 operates automatically to lower pallet 14 by an increment sufficient to accommodate the succeeding layer.

The apparatus will be programmed so that the next succeeding layer is differently orientated, e.g.

its pattern is the same as but turned 1 800 with respect to the first layer to bond the stack and make it secure in the manner illustrated in Figure 6.

Successive layers are built up until the pallet is fully loaded and, at the same time, has returned to the level of the lower feed path when it is pushed along rollers 13 out of framework 10 by the next succeeding empty pallet.

The provision for rotating carrier 21 means that a particularly secure stack can be built even if the sacks or other objects are somewhat irregular, in particular a sack which has been filled with a batch of such material as solid fuel will have a roughly tapered shape in that the end of the sack which was bottommost when filling will be more tightly packed than the neck or top end thereof.

The apparatus is programmed to arrange the thinner neck ends of sacks 30 (marked N in Figure 6), inwardly of the sides or corners of the stack so that the stack is more secure against slippage or dislodgement.

It will be observed that the sacks are not subjected to gripping or localised lifting forces so that the risk of damage to them or their contents is minimised, thus the apparatus can be employed for handling paper sacks of heavy material at quite high operating speeds, possibly around eight sacks per minute, with adaptability to different loading and stacking patterns or sequences. Thus the apparatus might be used with a wide range of products such as packaged fruit or vegetables with reduction in the risk of damage or wastage which can arise from careless manhandling or unsuitable automatic devices.

Complex mechanisms such as powered rollers, separate bag turning means and the like are not necessary and the apparatus is considerably simpler and more compact than many known automatic stacking devices.

Claims (12)

1. Stacking apparatus including distributing means for successively positioning a series of substantially uniform articles on a support to form a stack in successive layers superimpósed on each other and with each layer comprising a plurality of the articles in a prearranged relationship with each other and with any preceding layer; said distributing means including a carrier adapted to receive an article from a supply in use and movable both longitudinally and laterally of the stacking area, means for selectively releasing the article from the carrier at a predetermined location in said area, and means providing relative vertical movement between the distributing means and the area of the stackforthe building of successive layers.

2. Apparatus as in Claim 1 wherein the carrier is rotatable about a vertical axis for turning the article received thereby in use to a desired orientation in a horizontal plane with respect to other articles previously deposited.

3. Apparatus as in Claim 1 or 2 including supporting means operatively carrying an upper surface comprising the area on which the stack is formed, and means for lowering the supporting means progressively relative to the distributing means for the formation of the successive layers.

4. Apparatus as in Claim 3 wherein the supporting means is adapted to receive a pallet on whose upper surface the stack is operatively built.

5. Apparatus as in Claim 4 including means defining a lower feed path along which pallets are fed successively in use to the supporting means and loaded pallets are removed therefrom.

6. Apparatus as in Claim 5 wherein the lower feed path includes a roller conveyor.

7. Apparatus as in any preceding claim wherein the distribution means includes an overhead track, the carrier is downwardly depending from said track, and the latter is adapted for traversing movement of the carrier both longitudinally and laterally above the stacking area.

8. Apparatus as in Claim 7 wherein an article receiving portion of the carrier includes a floor of which is operable to release the article at the predetermined location.

9. Apparatus as in Claim 8 wherein said portion of the carrier is in the form of a basket having a floor formed in two parts and supported by respective pivoted frames whereby it can be opened in the manner of a clam-shell bucket.

10. Apparatus as in Claim 9 wherein said floor includes freely rotatable rollers and the basket when closed includes a side opening for receiving an article.

11. Apparatus as in Claim 10 including means defining an upper feed path at the level of said side opening along which articles are passed to the carrier in use.

12. Stacking apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.