GB2283739A - Rack storage systems - Google Patents

Abstract

A rack storage system has shelves 2 equipped with rollers 9 to ease the transfer of heavy articles 3 between the racking and mobile loading apparatus also equipped with rollers 10 which register with the rollers 9. The apparatus may be a fork lift truck, and means 7, 8 will be provided for ensuring that it docks correctly with the racking before its forks are brought forward and down to register with the desired shelf. The forks carry a frame 11 equipped with the further rollers 10 which align with those of the shelf 2. The forward edge of the frame can engage with supports 12 on the racking. The frame also has a displacer (21 Fig 6) with means 24 for coupling to an article 3 to be transferred, and on actuation it either draws the article off the shelf 2 onto the frame 11, or pushes it the other way. When the article is on the frame, it remains coupled for safety. <IMAGE>

Description

"ImDrovements relations to Rack Storaae Systems" This invention relates to rack storage systems. It is concerned with the problem of transferring heavy loads between rack shelving and a mobile loading/unloading vehicle such as a fork lift truck. It is important that, while the transfer is taking place, the vehicle should be firmly and accurately parked, that there should be no risk of overload and tilting while the operation is being carried out, and that the transfer should be as smooth and easy as possible.

According to the present invention there is provided a rack storage system comprising racking having arrays of rollers on which articles to be stored run as they are removed or stowed, and mobile loading apparatus for cooperation with the racking and provided with arrays of rollers to register with and effectively extend selected arrays of rack rollers when the apparatus is brought into loading/unloading relationship with the racking, and with means for pushing and pulling articles running on the rollers between the racking and the apparatus.

Conveniently, the articles will not just run on the rollers in the racking, but remain resting on them when stowed. Likewise, they will rest on the rollers on the mobile loading apparatus. There will of course then be means for limiting or preventing the ability of the articles to roll when the apparatus is separated from the racking. This may simply be a stop at the front of the racking associated with each set of rollers which may be spring biased into a stand-up position. An article being rolled onto the racking may then press it down, and when the article has passed, the stop may flip up again. Alternatively, when the loading apparatus comes into co-operation with the racking, power means may be energised to cause the stop to retract, or part of the apparatus may engage and lower the stop.

On the mobile loading apparatus, the push-pull means may remain engaged with the article to hold it on the rollers without stops or other means.

When the mobile loading apparatus is a completely independent vehicle (that is it does not run on rails or other fixed guidance system) it is advisable to have means to assist the driver to locate it properly in relation to the racking. This may comprise docking stops provided on or adjacent the racking and complementary stops on the truck.

That will be driven so that the docking stops mutually engage, and then the truck will be in the correct position for transfer. Conveniently, the docking stops will be on the floor and correspondingly low down on the front of the truck.

Preferably, the truck will have a platform with rollers that is raisable and lowerable on a structure that is itself capable of horizontal movement towards and away from the racking when docking is complete. This means that the platform does not have a chance to interfere with the racking while the truck is being correctly positioned. But when it is, its supporting structure can be shifted to bring it close up to the racking.

Preferably, this platform will have a formation at its free end that can engage and interlock with a complementary formation on the racking when the platform is lowered from a raised position. These formations may be simple hooks, and the ones on the racking, just below each roller level, will help support the platform as a load is transferred. They will also help prevent the truck shifting back away from the racking.

For a fork lift truck, the transfer means may comprise a frame with parallel flat tubular members into which the forks enter. Rollers with axes transverse to these members may be carried above them in parallel arrays. A powered traveller that can move from one end to the other can be disposed between these roller arrays and be provided with means positively to engage any article stowed or stowable on the racking. Conveniently, this traveller is a yoke spanning two guide rails adjacent and parallel to the tubular side members, and it may be driven by a central lead screw.

For a better understanding of the invention, one embodiment will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic front elevation of racking for storing heavy articles, Figure 2 is a diagrammatic side elevation of such racking and a fork lift truck co-operating with it.

Figure 3 is a diagrammatic side elevation of storage racking with parts of a fork lift truck showing movements as it approaches and leaves the transfer position, Figure 4 is a front elevation of racking showing various shelving arrangements, Figure 5 is a side elevation of a shelf of the racking with a load thereon, Figure 6 is a plan view of a load transfer frame which can be fitted to a fork lift truck, and Figure 7 is a detail, to an enlarged scale, of part of Figure 6.

The racking of Figure 1 has several bays 1 of different widths, and adjustable shelves 2 fixed at various heights.

The layout is designed to accommodate in as compact a space as possible various different sized heavy articles, diagrammatically illustrated by the rectangles 3. When required, such articles need to be pulled out from their shelves, and transferred to mobile apparatus to take them to the point of use. This is typically a fork lift truck 4 with a mast 5 carrying the forks 6. The latter can be shifted up and down the mast which is substantially as high as the racking, and the mast 5 itself can be shifted horizontally, forwards and backwards in the longitudinal direction of the forks.

For a transfer operation, the truck must be properly located in front of the desired bay, and this is achieved by floor stops 7 which are engaged by rollers 8 low down at the front of the truck 4. In plan view, the stops have divergent U-shaped recesses that locate the rollers, and hence the truck. While the truck 4 is being driven towards the racking the mast 5 is in the rearward position as shown in full lines in Figure 2, and the forks 6 are above the shelf 2 with which they are to co-operate. But when the truck is docked, the mast 5 is shifted forwards and then the forks are lowered to the position shown in broken lines in Figure 2.

Each shelf 2 presents parallel arrays of rollers 9 extending rearwardly from the front lip of the shelf to support and ease transfer of the articles stowed on that shelf. Likewise, the truck 4 has similar parallel arrays of rollers 10 carried on its forks 6 by a structure 11 to be described in more detail later. When on the truck, an article 3 rests on these rollers 10.

To achieve correct vertical registry between the roller arrays, projecting from the front of each shelf 2 and below the rollers there is a pair of upwardly open hooks 12 as best seen in Figures 3 and 4, and the platform or frame 11 (to be described in more detail later) carried by the forks 6 has a complementary pair of down-turned hooks 13 at its free, forward end. These hooks 12 and 13 inter-engage as the forks 6 of a docked truck 4 are lowered, and when they do the load-bearing surface on the forks (the rollers 10) is level with that of the shelf 3 (the rollers 9). It will be seen that, during load transfer, the free end of the loadbearing surface provided by the truck 4 is fully supported by the hooks 9 on the racking, and so there will be no risk of the truck toppling forwards. At the same time, the interengaging hooks will positively retain the truck adjacent the racking and prevent it accidentally rolling away leaving a dangerous gap.

Figure 4 illustrates that, for compact stowing using all the racking space available, at least some shelves in a bay may be adapted for receiving two side-by-side articles 3. In this case, it is the top shelf that is so adapted, and there are two side-by-side pairs of roller arrays 7, each with a pair of hooks 12 in front of them and, on the floor, corresponding extra stops 7 for the truck 4.

Referring now to Figure 5, the rollers 9 are mounted in horizontal frames 14 with their axes parallel to the front of the racking. The tops of the rollers are just proud of these frames. Towards the rear of each shelf 2, there is a stop 15 with an adjustable buffer 16. The stop 15 itself may be settable at various different positions, providing a coarse adjustment, while the buffer 16 provides a finer one.

At the front there is a stop 17 which projects upwardly as shown in Figures 6 and 7 to prevent the article rolling forwards off the shelf. Normally, it is upright, but it can be lowered down and raised as indicated by the double arrow in Figure 5 to leave the path clear for load transfer. There are various ways of arranging this. For example, it may be spring-biased towards its upright position, and when a load is transferred from the truck 4 to the shelf 2, it is simply pressed down by the article 3 itself. When that has passed, it flips up again. For the return, an operator may hold it down. Alternatively, there may be a latch mechanism which is operated when the hooks 12 and 13 inter-engage, thus causing the stop 17 to be lowered, while, when they disengage, it is brought upright again.

Referring now to Figure 6, the frame 11 for the fork lift truck 4 has on its underside a pair of parallel flat rectangular tubes 18. The forks 6 fit closely into these and, if desired, means may be provided for clamping them there. Above these there are sub-frames 19 carrying the arrays of horizontal rollers 10 similar to the rollers 9 of the rack shelves 2, the roller axes being perpendicular to the tubes 18. Just inside the sub frames 19 there are rails 20 extending their full length, and spanning these rails, and guided by them, is a yoke 21. This has an integral or fitted nut (not shown) which is engaged by a central longitudinal lead screw 22 driven by a hydraulic unit 23 at the rear end. On this yoke is mounted a load engager 24 which can be operated by another small hydraulic unit 25.

The load engager is shown in more detail in Figure 7.

Each article to be handled has fitted to it a H-section member 26, one 'vertical' of the H being bolted to the article itself and the other providing detents 27 for engagement by hooked jaws 28. These are L-shaped members pivoted to the yoke 21 at intermediate points 29 along their longer legs, and they have wedge formations 30 at their rear ends and on their outer sides. The hydraulic unit 25 is a ram whose rod carries a U-shaped member 31 at the ends of whose arms are rollers 32. These engage the outside of the jaws 28. When the unit 25 retracts the rollers 32, the jaws are wedged open (the lower half of Figure 7), while when the ram rod is extended, the jaws are closed around the detents 27 (the upper half of Figure 7).

For withdrawing an article from the racking, the truck 4 is positioned as described above, and the yoke 21 is shifted to the forward end of the frame 11 where the opened load engager 24 projects just beyond it. The jaws are then closed by operating the unit 25, thus coupling the article 3 to the yoke 21. The lead screw 22 is then operated to withdraw the yoke 21, and this pulls the article from the racking on to the truck platform 11. When fully on, the forks 6 can be raised to disengage the hooks 12 and 13 and the truck moved away. There is no need for a stop such as the stop 17; the load engager 24 will remain coupled and hydraulically locked to the load.

For returning the article to the racking, the reverse procedure is carried out, this time the yoke pushing rather than pulling the load. If there is any tendency for the load to skew, especially when being pushed back onto the racking, provision could be made for more than one load engager. Two horizontally spaced ones would cure the problem.

Claims (16)

1. A rack storage system comprising racking having arrays of rollers on which articles to be stored run as they are removed or stowed, and mobile loading apparatus for cooperation with the racking and provided with arrays of rollers to register with and effectively extend selected r aFays of rack rollers when the apparatus is brought into loading/unloading relationship with the racking, and with means for pushing and pulling articles running on the rollers between the racking and the apparatus.

2. A rack storage system as claimed in Claim 1, wherein the articles remain resting on rollers in the racking when stowed and on the rollers on the mobile loading apparatus when being transported, there being means for limiting or preventing the ability of the articles to roll when the apparatus is separated from the racking.

3. A rack storage system as claimed in Claim 2, wherein the limiting or preventing means on the racking comprises a stop at the front of the racking associated with each set of rollers spring biased into a stand-up position.

4. A rack storage system as claimed in Claim 3, wherein the stop is arranged so that an article being rolled onto the racking presses the stop down, and when the article has passed, the stop flips up again, there being means for holding the stop down when the article is removed from the racking.

5. A rack storage system as claimed in Claim 3, wherein the loading apparatus coming into co-operation with the racking causes the stop to project.

6. A rack storage system as claimed in Claims 3, 4 or 5, wherein the limiting or preventing means on the mobile loading apparatus is provided by the push-pull means which remains engaged with the article to hold it on the rollers without stops or other means.

7. A rack storage system as claimed in any preceding claim, wherein the mobile loading apparatus is a completely independent truck (that is it does not run on rails or other fixed guidance system) and wherein means are provided to assist the driver to locate it properly in relation to the racking, these locating means comprising docking stops provided on or adjacent the racking and complementary stops on the truck.

8. A rack storage system as claimed in Claim 7, wherein the docking stops are on the floor and correspondingly low down on the front of the truck.

9. A rack storage system as claimed in Claim 7 or 8, wherein the truck has a platform with rollers that is raisable and lowerable on a structure that is itself capable of horizontal movement towards and away from the racking when docking is complete.

10. A rack storage system as claimed in Claim 9, wherein the platform has a formation at its free end that can engage and interlock with a complementary formation on the racking when the platform is lowered from a raised position.

11. A rack storage system as claimed in Claim 10, wherein the formations on the racking are adapted to help support the platform as a load is transferred and to help prevent the truck shifting back away from the racking.

12. A rack storage system as claimed in any one of Claims 7 to 11, wherein the truck is a fork-lift truck and is provided with transfer means in the form of a frame with parallel flat tubular members into which the forks enter and with rollers with axes transverse to these members carried above them in parallel arrays.

13. A rack storage system as claimed in Claim 12, wherein a powered traveller which can move from one end to the other of the frame is disposed between the roller arrays and is provided with means positively to engage an article stowed or stowable on the racking.

14. A rack storage system as claimed in Claim 13, wherein the traveller is a yoke spanning two guide rails adjacent and parallel to the roller arrays.

15. A rack storage system as claimed in Claim 14, wherein the yoke is driven by a central lead screw.

16. A rack storage system substantially as hereinbefore described with reference to the accompanying drawings.