GB2237549A

GB2237549A - A method and a device for automatically forming a stack

Info

Publication number: GB2237549A
Application number: GB9022800A
Authority: GB
Inventors: Reinhard Milde; Theo Buschhaus; Jurgen Baier
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1989-11-01
Filing date: 1990-10-19
Publication date: 1991-05-08
Also published as: DE3936764C2; FR2653758A1; DE3936764A1; IT9021763A0; GB9022800D0; IT9021763A1; IT1243452B

Abstract

The invention relates to a method and a device for automatically forming a stack, comprising a plurality of layers of packages, between which are arranged separators with upwardly and downwardly extending marginal zones 13a, 13b which abut against the upper and lower layers. The marginal zones are formed by thrusting a separator into a horizontally- disposed, vertically displaceable frame (14, Figs 1 and 2) having horizontally-pivoted and displaceable side walls 15. In forming the stack, the downwardly extending marginal zones 13a of the separator are displaced outwards on pivoting of the frame side walls in one direction for positioning the separator on a layer of packages, and the upwardly extending marginal zones 13b are displaced outwardly on pivoting of the frame side walls in the other direction for the subsequent positioning of the next layer in the separator with corresponding inward displacement of the downwardly extending marginal zones. One side of the frame is openable to allow removal of the completed stack. <IMAGE>

Description

-I- A METHOD AND A DEVICE FOR AUTOMATICALLY FORMING A STACK The Invention

relates to a method and a device for automatically forming a stack, comprising a plurality of layers of packages between which are arranged separators with upwardly and downwardly bent margin zones which abut against the upper and lower layers.

A package Is to be understood as a bag-like container, the sides of which are not stable and accurately dimensioned as in the case of a conventional carton. Such packages are known for example as containers of articles of hygiene. disposable nappies etc. It is difficult to stack such packages on pallets to a height of about 2 metres because of the unstable nature of the packages, and therefore the individual layers must be secured by interposed cardboard bases and additional outer bindings which can be formed for example by the bent edges of the cardboard bases. The formation of the bent edges and the introduction of the separators is difficult and time consuming.

Therefore the aim of the invention is to provide a method of automatically forming a stack on a pallet. This aim is fulfilled by the features of the characterising part of the main claim. The special manipulating frame deforms the specially punched out and pre-folded margins of the separators so that on the one hand they secure and support the lower layer and on the other hand, for the reliable positioning of the next layer, their upper margin Is drawn outwards whereby the side walls of the manipulating frame support the downwardly directed margins of the separators.

A device for the implementation of the method comprises. above a palletizing station. a height-adjustable manipulating frame. the side walls of which can be swivelled about horizontal longitudinal axes which are arranged at about half the height of the side walls. When the separator is placed In position these swivelling side walls form a downwardly open funnel whilst, for the positioning of the next layer of packages, the manipulating frame Is compressed at the bottom and forms and upwardly open funnel for the easy introduction of the layer. The side walls of the manipulating frame, which can also be expanded overall, can be provided with suction cups and/or fixing channels which serve to retain and guide the bent separator margins.

An exemplary embodiment of the device corresponding to the invention is illustrated in the drawings and explained in the following.

Figure 1 Is a side view of a palletizing station; Figure 2 is a plan view of Figure 1; Figure 3 Illustrates the movements of a side wall of a manipulating frame during the formation of a layer of a stack; Figure 4 Is plan view of a manipulating frame In different positions; j, Figure 5 is a section V - V through Figure 1 on an enlarged scale; and Figure 6 shows a detail A from Figure 5 on an enlarged scale.

Four supports 1 bear two longitudinal carriers 2 along which a travelling carrier 3 of a robot 4 can be moved. The robot 4 comprises a lifting column 5 with a combined suction- and jaw-gripper 6. A lower pallet conveyor 7 conveys pallets 8 and a higher conveyor belt 9 conveys packages 10 to an assembly station 19. From here they are conveyed by the robot 4 by means of the jaw gripper 6 to the palletizing station 11. A stack of separators 12 arranged at the side is supplied by a fork-lift truck (not shown) with roughly prepositioned cardboard separators 13 which, with the assistance of the robot 4., the suction gripper 6 and optical sensors (not shown), are accurately positioned over an manipulating frame 14 provided with suction elements 18.

The manipulating frame 14 comprises a U-shaped carrier frame 14a, at the free ends of which are attached respective ones of a pair of carrier arms 14g which can be swivelled about vertical axes 17, as illustrated in Figures 2, 4b to 4d and 5. On the Inwardly facing sides of the carrier frame 14a and on the inwardly facing sides of the two carrier arms 14g are arranged side walls 15 which are seen in detall In Figures 3 and 6, and can each be swivelled about a horizontal axis 16 and can be moved outwardly and upwardly of the frame 14.

The carrier frame 14a is guided by a guide element l4b on a guide rail of a laterally arranged support 14c. The entire carrier frame 14a can be raised and lowered by a toothed belt 14d driven by a electric motor l4e. The actual position of the carrier frame 14a is detected by a potentiometer 14f attached to the electric motor l4e.

Figures 3a to 3h illustrate the sequence of operation of the side walls 15 of the manipulating frame which are provided with fixing channels 15a and/or suction cups 18. At 3a the separator 13 is conveyed from the stack 12 of separators to above the manipulating frame 14 and is centred at 3b. At 3c the separator 13 is pressed into the manipulating frame 14, whereby the outer margins 13b of the separator 13 are bent downwardly and the areas 13a are bent upwardly as the separator moves along the side wall 15. At 3d the side wall 15 is lowered so that the fixing channel 15a moves over the upper edge of the outer margin 13b of the separator 13. At 3e the lower margin 13a of the separator 13 is moved outwardly by an inward pressure on the margin 13b to form a funnel and at 3f the separator 13 is positioned onto the layer 10 of packages. A 3g the lower margin 13a is pressed inwardly by the side wall 15, which can be tilted about the horizontal axis 16, and compresses the upper margin of the stack of packages, whereas the upper margin 13b of the separator 13 widens in a funnel formation for the introduction of the next layer as shown at 3h. When this new layer has been completely placed in position, the side walls 15 move away from the stack of i packages In accordance with 3i, and the entire manipulating frame 14 is raised by the height of a package, as indicated at 3j, for the formation of the next layer.

Figure 4a is a plan view of the side walls 15 of a manipulating frame with a divided front side wall 15b. The flanks of this divided side wall 15b can be swivelled about vertical axes 17 so that a completed stack of packages can be moved out of the thus opened manipulating frame.

At the same time the possibility exists that, with the front side wall 15b open, the bending of the separator margins can be limited to three sides, as illustrated in Figure 4c. If, during the centering in accordance with Figure 3b, the separator 13 is not positioned centrally at the point ZI shown in Figure 4d but eccentrically at the point Z2, the flanks of the divided side wall 15b remain open and only two lateral margins of the separator 13 are bent, as indicated in Figure 4d.

The described method permits, in particular, a reliable formation of layers in accordance with Figures 3f and 3g, even if the layers 10a of packages have excess widths.

The arms 20 which are shown in Figure 2 and which retain the side walls 15 in the'manipulating frame 14 are shown on an enlarged scale in Figure 6 to explain the various possible movement functions of the side walls 15. The arms 20 support a guide 21 in relation to which is fixed the longitudinal axis 16 for pivoting the side wall 15. The side wall 15 has an attachment point 22 for an expanding device 23 In the form of a piston, operating on both sides, of a pressure cylinder which Is articulated to a bearing lug 24 of the guide 21. The guide 21 Is axially displaced by a double-acting piston of a pressure cylinder 25 In order to move the guide 21 towards or away from a stack of packages. as Indicated by arrow 31 In Figure 6.

By operation of the pressure cylinder 25, the side wall may be moved to the left or right as shown In the figure. An anti-clockwise or clockwise rotation may be Imparted to the side wall 15 by operating the expanding device 23.

Claims

PATENT CLAINS

1. A method of automatically forming a vertical stack comprising a plurality of layers of packages between which are arranged horizontal separators with margin zones upwardly and downwardly extending which abut against the layers of packages adjacent the separators, characterised in that the margin zones of the separators are deformed by a manipulating frame which 1. bends the margin zones to extend substantially perpendicularly from the separator, 2. opens the margin zones at the bottom in a funnel formation, positions the separator from above onto a layer of packages so that the downwardly directed margin zones retain the underlying layer of packages. opens upwardly extending margin zones of the separator In a funnel formation, where a lower position of the manipulating frame simultaneously supports the downwardly directed margin zones of the separator and thus also shapes the lower layer of packages, in order to form the next layer is expanded and raised by the height of a layer. and one of whose side walls Is opened up after the formation of the uppermost layer. to allow the stack to move out of the frame.

2. A device for implementing the method claimed in Claim 1, characterised In thgt above a palletizing station (11) Is arranged a height-adjustable manipulating frame (14), having operative side walls (15) arranged therein so as to be able to be swivelled about respective horizontal longitudinal axes (16) arranged at about half the height of the side wails.

3. A device as claimed In Claim 2, characterized In that the side walls (15) are arranged so that they can be moved away from one another.

4. A device as claimed In Claim 2, characterised In that at least one of the side walls (15b) and Its respective part of the frame (14), can additionally be swivelled about a vertical axis (17) to open the frame.

5. A device as claimed in Claim 4, characterised In that the side wall (15b) and the associated wall (14a) of the manipulating frame (14) are divided Into two halves. which can each be swivelled about a vertical axis (17).

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6. A device as claimed in Claim 2, characterised in-that the side walls (15) of the manipulating frame (14) are provided with suction cups (18).

7. A device as claimed In Claim 2, characterised in that the side walls (15) of the manipulating frame (14) are provided with fixing channels (15a).

8. A device as claimed In Claims 2 and 3, characterised In that the manipulating frame (14) has inwardly directed arms (20) with displaceable guides (21) for the horizontal longitudinal axes (16) of the side walls (15) which, and the sidewalls, have attachment points (22) spaced from the longitudinal axes (16) for expanding devices (23) which are articulated to bearing lugs (24) of the displaceable guides (21).

9. A device as claimed In Claim 8. characterised In that the guides (21) can be displaced by pistons of double-acting pressure cylinders (25).

10. A device as claimed in Claim 8, characterised In that the spreading devices (23) are double-acting pressure cylinders.

11. A device substantially as herein described with reference to Figs. 1 to 6 of the accompanying drawings.

Published 1991 at1be Patent Office.St2te House, 66/71 High Holborn. LDndonWCIR4rP. Further copies Tmy be obtained from Sales Branch, Unit 6. Nine Mile Point, Cwmiclinfacb. Cross Keys. Newport. NPI 7HZ. Printed by Multiplex techniques ltd, St Mary Cr2y. KenL