GB2280178A

GB2280178A - Handling palettes in a warehouse

Info

Publication number: GB2280178A
Application number: GB9414203A
Authority: GB
Inventors: Hermann Grebenstein
Original assignee: OWL AG LOGISTIK SYSTEME
Current assignee: OWL AG LOGISTIK SYSTEME
Priority date: 1993-07-14
Filing date: 1994-07-14
Publication date: 1995-01-25
Also published as: DE4422240A1; NL9401166A; BE1008490A3; FR2708578B1; FR2708578A1; GB9414203D0

Description

Process and device for handlina palettes 2280178 The invention relates to

a process and device for handling transport supports such as palettes, in particular for inserting them into and extracting them from a racking arrangement in a warehouse.

Known devices (e.g. CH-PS 41 64 62) for handling or arranging and removing transport supports, in particular flat rectangular bases such as palettes, in shelf storage depots, have transfer devices such as shelf access devices or stacking trucks which are provided with lifting platforms or platforms with telescopic arms, by means of which a palette can in turn be lifted, moved into the shelf and then set down on the shelf.

Since by this method only one row of shelves on either side of the shelf access device can be loaded with palettes poor usage is made of the storage space.

By means of correspondingly long telescopic arms the possibility does exist of loading a second row of shelves with palettes, but for greater loads the telescopic arms have to be of correspondingly robust construction which requires a greater shelf height in addition to the placing and removal movement. Good use of space cannot be achieved here either.

It is the aim of the present invention to provide a process and a corresponding device in which the transport supports are handled in such a way during loading of storage shelves that the spatial volume of the storage area can be better utilised.

According to one aspect of the invention there is provided a process for inserting or withdrawing transport supports into or out of a shelf by means of a transfer device, in which the transfer device engages the support in a direction transverse to the insertion direction and slides it on to or off the shelf. A second aspect relates to a device for transferring a transport support to or from a shelf, comprising a transfer device which has two extensible, generally parallel arms on a lifting platform, characterised in that each arm has entrainers for engaging the supports and in that the arms can be moved towards and away from each other so that the entrainers engage the support.

The arms of the transfer device therefore do not have to take the weight of the palettes, which means that they can be much lighter than hitherto. They are preferably telescopic and include a gripping means which engages the palette - for instance, hook-like protrusions which engage a leg of the palette.

Engagement is achieved by the transverse movement of the arms, preferably towards and away from each other in the horizontal plane but as a possible alternative vertically; this movement would be similar to a conventional lift with the difference that the palette is not lifted completely off the shelving.

When the movement of the arms is opposed to each other, that is when the palettes are engaged laterally, in the horizontal plane, the engagement could be purely frictional, though it is advantageous to provide an element of positive engagement such as the protrusions mentioned. Such positive engagement is still more strongly recommended when the engagement with the palette is upward, since the counterbalancing force is then provided only by the weight of the load.

An embodiment of the invention will now be described by way of example, with reference to the attached drawings. The drawings show: Fia. 1 Fig. 2 Fig. 3 a VIew transversely through a shelf storage area with a transfer device representing a first embodiment of the invention; a side view of the transfer device; a plan view corresponding to Fig. 1; Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 the storage and adjustment device for the telescopic arms on the platform of the transfer device; a plan view corresponding to Fig. 4; variant of the adjustment device in a view corresponding to Fig. 5; a variant transport support in perspective view; a plan view corresponding to Fig. 3 of a second embodiment using transport supports according to Fig. 7; a partial plan view corresponding to Fig. 3 of a third embodiment in which the transport supports can be inserted longitudinally, and Fig. 10 a variant of the Fig. 9 embodiment.

Figs. 1, 2 and 3 show a transfer device 1 constructed as a shelf access device or vehicle which can be moved in an aisle 2 between shelves 3 of a warehouse, arranged on both sides of it. The device inserts and removes transport supports 4 loaded with goods such as palettes - preferably Europalettes. The movement of the vehicle is in the x-direction on rails 5 for moving to individual rows of shelves. The transfer device 1 has a lifting platform 6 which can be moved in the vertical direction (ydirection) for accessing rows of shelves on various levels. 30 Two telescopic arms 7 arranged parallel to each other are disposed on the lifting platform 6 and comprise one or more rails extensible to both sides in the horizontal direction (z-direction). As can be seen from Figs. 1 and 3 the telescopic arms in the exemplary embodiment have two rails 8 and 9 which can be pulled out like a telescope in either direction, each pair of rails consisting of an inner rail 8 and an outer rail 9.

The outer rails 9, i.e. those furthest out when the arms are telescoped, are provided with entrainers 10 which are directed inwardly, i.e. facing each other, according to the embodiment shown in Fig. 3.

The two telescopic arms 7 can be moved on the lifting platform 6 in the xdirection by an amount dx. When the two arms are extended to surround a palette this displacement towards each other causes the entrainers 10 to engage into the palette 4.

Between the two telescopic arms 7 the lifting platform 6 has an endless conveyor 11 which comprises two conveying webs 11a arranged parallel with respect to each other, and has a conveying action in the direction of the shelves 3, i.e. in the z-direction.

The endless conveyor 11 is preferably constructed as a chain conveyor but can also be a belt conveyor or toothed belt conveyor.

The shelving 3 has support rails 12 which are substantially coaxial to the conveying webs lla, though they may instead be laterally displaced (see Fig. 3 or 8). These rails 12 are preferably provided with a coating having a low friction factor, or are made of an appropriate wear-resistant material for easy displacement of the palette 4.

The endless conveyor 11 can be moved bodily in the z-direction by an amount dz in order to move it up to the shelves, i.e. to the ends of the support rails 12.

The endless conveyor 11 is preferably moved together with the telescopic arms 7 and the lifting platform 6, thus providing additional guiding length for the telescopic arms 7.

Shifting of the endless conveyor or the entire lifting platform 6 is necessary in order to reduce to a minimum the prescribed intervening spaces between it an.0 the shelving 3 for trouble-free transfer of the transport supports or palettes 4 onto the shelf or back to the lifting platform 6.

Figs. 4 and 5 schematically show the adjustment or actuation device 20 for the telescopic arms 7 on the lifting platform 6.

The telescopic arms 7 are mounted on guideways 21 so as to be movable in the x-direction and can be moved towards or away from each other by means of an adjustment drive 22 respectively by the amount dx.

The adjustment drive 22 has a geared motor 23 or other rotary drive which drives a cam 24, for instance a crankshaft. The telescopic arms or forks 7 are joined or eccentrically articulated by means of rods 25 to the cam 24, the displacement of the telescopic arms 7 by the amount dx being effected through the rotary movement of the cam 24.

The rods 25 can be joined directly to the telescopic arms 7 or, as can be seen in Fig. 5, with the interposition of a spring 26. The spring 26 makes possible an additional closure path so that the entrainers 10 engage better or more securely.

It would also be possible to provide an individual adjustment drive 22 for each telescopic arm 7, the rotary drives 23 being driven in an electrically coupled manner for uniform adjustment. In the case of two independent adjustment drives a palette which has moved out of true can also be found and set straight by means of an appropriate sensor device. 30 In the variant of the adjustment device 20 shown in Fig. 6 the rods 25 are each connected to a respective longitudinal bar 27 which is operatively connected to the telescopic arm 7 by means of springs 28. The rails 8 and 9 of the telescopic arms 7 can be pulled out or retracted by means of a shift drive (not shown in detail), e.g. by means of a geared motor and a chain drive.

The entrainers 10 arranged on the rails 9 (see Fig. 1) are preferably designed as rotatably mounted rollers. Their surface is here of such a nature that on pressure against the palette 4 they enter into a forcefitting or frictional connection. Four entrainers 10 are arranged on each rail 9, two entrainers 10a being arranged at one end for the insertion or removal of palettes into or out of the left-hand shelves 3b, and correspondingly two entrainers 10b being arranged at the other end for the insertion or removal of palettes into or out of the right-hand shelf 3a.

To insert a palette 4 into the shelving 3 the lifting platform 6 is first of all moved in front of the appropriate set of shelves and displaced to one side by the amount dz towards the shelving 3. The palette 4 is moved by means of the endless conveyor 11 far enough for the entrainers 10a or 10b to engage into the palette 4, which is then done by shifting the telescopic arms 7 towards each other by the amount dx. By extending the rails 8 and 9 of the telescopic arms 7, with simultaneous drive of the endless conveyor 11, the palette 4 is pushed onto the support rails 12 of the shelf 3, and there it is shifted solely by means of the telescopic arms 7 into the storage position of the second or first row by urging the entrainers 10 which engage into the palette 4 and are held there by the drive 22 or a brake device.

Removal from the shelf is correspondingly carried out in reverse. During both processes the weight of the palette is taken by the shelf rails 12 until the palette is on the platform.

By gripping the palettes laterally, that is transverse to the insertion/removal direction z, and S1 iding them on to support rails in the shelves at least two rows of shelves arranged one behind the other can be served by means of the transfer device, the telescopic arms only having to be designed for the displacement or gripping force and not for carrying forces, thus enabling their cross-sectional dimension to be correspondingly small.

Fig. 7 shows a variant form of transport support which is designed as a transport frame 4a and can be used instead of the palettes described above.

At its corners the transport frame 4a has feet 4b which, as can be seen in Fig. 8, are gripped from inside by the entrainers 10 of the telescopic arms 7.

To grip the transport frame 4a the telescopic arms 7 are pushed away from each other, which is carried out with adjustment devices similar to the devices described with respect to Figs. 4, 5 and 6.

Insertion or withdrawal of these transport frames 4a into or out of the shelves 3 is effected in the same way as already described above with regard to Figs. 1 to 3.

In the embodiment according to Fig. 3 the palettes 4 are stored transversely to the direction of travel of the shelf access device, which is sensible because of the smaller telescopic path necessary and because of the necessary support of the standard palettes (VDI Guideline 3655).

However, storage areas with goods structures wherein longitudinal storage produces better utilisation and performance data are conceivable. following variants or solutions are described below. ' Fig. 9 shows the insertion of a transport support 4 or palette into the shelf from the lifting platform 6 of the transfer device 1 in the longitudinal direction of the palette 4.

The entrainers 10 of the telescnpic arms 7 engage, from inside, the nearest abutting outer blocks 40a of the palettes 4, the gripping being effected from inside as already described with regard to Fig. 8. Shifting of the telescopic arms 7 away from each other by the amount dx is therefore necessary in order to grip the palette.

With engagement on the front block 40a there is the advantage of short telescopic shift movements, endless conveyors 11 being necessary on the lifting platform 6 for this - in the embodiment shown, the endless conveyor 11 has three conveyor webs lla. In the variant shown in Fig. 10 the entrainers 10 engage from the inside on the central blocks 40b. 15 The palette 4 can thus be pulled completely on to the lifting platform 6 and therefore no endless conveyor 11 is required. The disadvantage is that the telescopic shift path of the telescopic arms 7 has to be greater. 20 In a variant (also not shown) the entrainers 10 of the telescopic arms 7 engage inwardly on the centre board of the palette 4 which extends transversely over the centre block 40b. To grip the palette the entrainers 10 are arranged on the upper side of the telescopic arms 7. The gripping movement in the ydirection is effected by the lifting unit of the lifting platform 6 moving upwards by an amount dy.

The advantage in this is that no shifting mechanism for the dx-movement of the telescopic arms is necessary and the palettes can be pulled completely onto the lifting carriages, their weight being taken up to this point at least partly by the shelving itself. No endless conveyors 11 are necessary. The disadvantage is that the telescopic shift path has to be greater.

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Claims

Claims:

1. Process for inserting or withdrawing transport supports into or out of a shelf by means of a transfer device, in which the transfer device engages the support in a direction transverse to the insertion direction and slides it on to or off the shelf.

2. Process according to claim 1, which the engagement of the transport support is effected by a positivelocking or frictional abutment.

3. Process according to claim 1 or 2, in which during at least part of the transfer movement not all of the weight of the support is taken up by the transfer device.

4. Process according to claim 1, 2 or 3, in which two transport supports can be positioned into the shelf in one level one behind the other, being inserted or withdrawn one after the other.

5. Process according to any preceding claim, in which the transfer device engages the support by means of two extensible arms which can be moved towards or apart from each other horizontally into engagement with the support.

6. Device for transferring a transport support to or from a shelf, comprising a transfer device which has two extensible, generally parallel arms on a lifting platform, characterised in that each arm (7) has entrainers (10) for engaging the supports and in that the arms (7) can be moved so that the entrainers engage the support.

7. Device according to claim 6, in which the arms (7) are arranged to be movable horizontally towards and away from each other.

8. Device according to claim 6 or 7, in which the telescopic arms (7) can be moved by means of at least one adjustment drive (22).

9. Device according to claim 8, in which the adjustment drive (22) has drivable cams (24) and the telescopic arms (7) are joined by means of rods (25) to the cams (24).

10. Device according to claim 9, characterised in that the rods (25) are articulated on the cams (24) and connected to the telescopic arms (7) with the intermediate connection of springs (26, 28).

11. Device according to one of claims 8 to 10, in which one adjustment drive (22) is arranged for each telescopic arm (7).

12. Device according to claim 11.. in which the two adjustment drives (22) are controlled and regulated by means of sensors.

13. Device according to any of claims 6 to 12, in which each telescopic arm (7) has one or more telescopic rails (8, g), the entrainers (10) being arranged on the extreme rails (9).

14. Device according to claim 13, in which the rails (8, 9) can be telescoped by means of a hydraulic, pneumatic or electrical shift drive.

15. Device according to any of claims 6 to 14, in which endless conveyors (11) are arranged generally parallel to the telescopic arms (7) on a lifting platform (6) of the transport device (1).

16. Device according to claim 15, in which the lifting platform (6) with the telescopic arms (7) and the endless conveyor (11) is designed to be movable towards a shelf (3) by an amount dz.

17. Device substantially as described herein with reference to any of the embodiments shown in the accompanying drawings.

18. A warehousing system include shelving arranged in aisles and one or more transfer devices as claimed in any of claims 6 to 17, arranged to move in the aisles.

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