EP2945893A1

EP2945893A1 - A pallet stacking apparatus

Info

Publication number: EP2945893A1
Application number: EP14704870.6A
Authority: EP
Inventors: Simon Eccleston
Original assignee: Pallet Eater Ltd
Current assignee: Pallet Eater Ltd
Priority date: 2013-01-15
Filing date: 2014-01-13
Publication date: 2015-11-25
Also published as: GB201300652D0; WO2014111698A1

Abstract

The present invention provides a pallet stacking apparatus (20) for safely and reliably stacking a plurality of pallets (50). The apparatus comprising a motor, first and second guide arms (22a, 22b) defining a pallet receiving space (26) therebetween, a lifting mechanism (38) operably connected to the motor and comprising an engaging means (28) arranged to be releasably engageable with a side of a pallet. The engaging means are operable to be reversibly translatable in a vertical plane under the action of the motor, so as to elevate a first pallet to a first stacking position, and to enable a second pallet to be received into the space defined by the first and second guide arms. The stacking operation is repeated until a stack of pallets is formed, whereupon the apparatus can be disengaged and moved to the next stacking location.

Description

The present invention relates to a stacking apparatus, and more particularly, to a pallet stacking apparatus for collating and stacking pallet bases.

Pallets or more specifically pallet bases are commonly used as a support substrate for many goods and products. Pallets may vary in size and are typically made from wood. The general structure of a pallet is a two layer substrate, usually formed from spaced planks, and consisting of short vertical support members to separate the two layers. The sides of the pallet usually have openings therethrough to enable a lifting system to engage with and lift the pallet above a floor surface (such as the floor of a depot, warehouse factory, store or other work environment etc.). Conventional lifting systems for pallets include manually-operated hydraulic 'trolley type' jacks and fork lift trucks. Both of these systems make use of relatively long, elongate forks that are inserted into the openings of the side of the pallet, which can then be elevated by mechanically (e.g. hydraulically) raising the forks, and in turn the pallet.

Although such systems provide a reliable technique of lifting and moving pallets in and around a work environment, they are not particularly well suited for performing stacking operations of the pallets after use (e.g. once the goods and products have been removed). Moreover, in the case of trolley jacks, even though they are generally manoeuvrable, there is a physical limit to the size or height of the stack that can actually be built up (due to weight considerations), as they do not possess any motive force themselves other than that provided by the manual operator. In addition, the operator must also take great care when using a trolley jack to avoid the stack from toppling or tipping over, which can occur if the height of the stack becomes too high and/or if poor alignment of the pallets occurs during stacking. The use of fork lift trucks can mitigate against some of these drawbacks but the outlay for such a system may be prohibitive, while the operator of a fork lift truck also requires training and certification for safe and legal use of the vehicle. Furthermore, as with the use of trolley jacks, poor alignment and/or positioning of the pallets while stacking may lead to a potential toppling or tipping hazard.

Hence, it is an object of the present invention to address some, if not all, of the above problems in the art, by providing an apparatus that can safely and reliably collate and stack a plurality of pallets.

According to a first aspect of the present invention there is a provided a pallet stacking apparatus, comprising:

a motor;

first and second guide arms defining a pallet receiving space therebetween;

a lifting mechanism operably connected to the motor and comprising:

an engaging means arranged to be releasably engageab!e with a side of a pallet,

wherein the engaging means are operable to be reversibly translatable in a vertical plane under the action of the motor, so as to elevate a first pallet to a first stacking position, and to enable a second pallet to be received into the space defined by the first and second guide arms.

The provision of a pallet stacking apparatus comprising first and second guide arms defining a pallet receiving space therebetween and a lifting mechanism having an engaging means for releasably engaging with a side of a pallet to enable a first pallet to be elevated to a first stacking position, and allowing a second pallet to be received into the space defined by the first and second guide arms is found to be particularly advantageous, as the guide arms perform reliable alignment of the pallets during stacking, in this way, a plurality of pallets may therefore be built up into a stack without the risk of any toppling or tipping of the pallets after stacking. By contrast, conventional trolley type jacks and fork lift trucks etc. provide no lateral support or guidance during stacking or lifting, and hence no alignment, which may allow the pallets to topple after being stacked.

Moreover, another advantage of the guide arms is that they provide an easy way of collating 'abandoned' pallets (e.g. those that have been left lying around on the floor surface of the work environment), as an operator can move the apparatus towards a pallet and effectively 'sweep up' the pallet into the space defined by the gap between the guide arms. it is be understood herein that any references to 'work environment' are intended to include, but are not limited to, environments such as a depot, warehouse, factory, store or backroom of a retail outlet etc. Hence, any references to a ' floor surface' should be taken to be a floor of such a work environment, whether that be a basement, ground floor or any subsequent higher floors etc. The first and second guide arms are preferably in the form of erect side walls (or effectively 'side cheeks') in which is preferably mounted the reversibly, vertically translatable engaging means. In preferred embodiments the spacing or gap between the guide arms is fixed, but in other embodiments may be adjustable depending on the particular application or implementation so as to accommodate different sizes of pallet. The space defined by the gap between the first and second guide arms corresponds to a volume in which the pallets are received and stacked.

The stacking operation is performed by elevating a first pallet to a first stacking position, while, during or subsequently receiving a second pallet into the spaced defined by the guide arms, which is now vacated by having elevated the first pallet to the first stacking position. By 'first stacking position' we mean an elevated plane above the floor surface, which is at a height that is preferably at least the height of a pallet to thereby enable the second pallet to be received into the space defined by the guide arms beneath the first pallet.

In preferred embodiments, the engaging means are further operable to release the first pallet on top of the second pallet. The stacking operation then continues by preferably releasably engaging the second pallet, in like manner to the first pallet, and elevating the second pallet to the first stacking position and the first pallet to a second, higher, stacking position. Hence, in this way a stack may eventually be formed by repeating the above preferred stacking operation.

It should be appreciated that there may be any number of successive stacking positions, each higher (above the floor surface) than the other and spaced by at least the height of a single pallet, with the number of stacking positions being determined by the desired height of the stack and the particular application or implementation. However, it is to be understood that the apparatus of the present invention is inherently scalable and therefore various stack heights and any stacked numbers of pallets may be accommodated by the present apparatus.

In particularly preferred embodiments, the engaging means of the lifting mechanism may comprise at least one retractable latch pivotally mounted in each of the guide arms. The latch is preferably arranged to engage with a respective side of a pallet. In exemplary embodiments, there is preferably two latches per guide arm, with each pair of latches being positioned so as to engage with a respective opening on a respective side of the pallet. Each latch is preferably a 'wedge-shaped' protrusion comprising a flat planar upper surface for engaging with the underside of the top surface layer of the pallet through a respective side opening of the pallet. In preferred embodiments, each latch is biased towards a substantially horizontal orientation, namely substantially parallel to the floor surface and to the plane of the pallet. The biasing may be achieved by way of a spring or spring mechanism, but may alternatively or additionally be accomplished by action of the latch's own weight, such that it can pivot under the action of gravity into a horizontal orientation. In this way, each latch is able to self-position or self-deploy when it is in the vicinity of a respective opening on the side of the pallet. To perform the above stacking operation, the lifting mechanism then translates the engaging means in a vertical plane, which has the effect in preferred embodiments of engaging the latches with the underside of the upper layer of the pallet so as to lift the pallet upwardly to the successive stacking position, in order to release the pallet, the lower surface of the latch preferably has a tapered surface, which is operable to tilt the latch into a substantially vertical orientation as the engaging means moves towards the floor surface, i.e. downwardly through the stack.

Therefore, in preferred embodiments, as the tapered undersides of the latches brush against the sides of the pallets, the latches are tilted (i.e. pushed) away from the horizontal, allowing the engaging means to return to their original position at or towards the base of the apparatus.

Preferably, at the bottom of the travel of the latches a fixed stop is provided, which preferably reversibly locks the latches in a substantially vertical orientation so that the stack may be released or to allow a further pallet to be received into the space defined by the guide arms.

In preferred embodiments, the lifting mechanism is operably connected to the motor via a geared mechanism or flexible linkage. Any suitable gearing or chain/belt linkage may be used in order to effect reversible vertical translation of the engaging means relative to the guide arms and floor surface.

The motor may he any motor that is electrically powered or powered by an internal combustion engine (e.g. petrol or diesel). The function of the motor is to provide power to the lifting mechanism and preferably to also provide a controllable motive force to the apparatus, enabling the apparatus to be translated across a floor surface. As a result, the apparatus of the present invention may in particularly preferred embodiments be 'driven' by an operator under its own power, such that the apparatus can be translated across the floor surface of a work environment in order to collate and stack discarded pallets.

It is envisaged that the apparatus will preferably be 'driven' in the sense that an operator guides or steers the direction of the apparatus by using a control mechanism, such as handle bars or a control stick etc. This is in contrast to physically sitting on or in the apparatus in the manner of a vehicle, such as fork lift truck etc. as the latter would require specialised vehicle training and certification. However, it is to be understood that embodiments in which an operator sits on, in or atop the apparatus are not excluded by the present invention, and do nevertheless fall within the scope of the invention.

In all embodiments, the apparatus preferably comprises a set of wheels or rollers to enable translation of the apparatus across the floor surface of a work environment. However, any suitable form of translation means may be used in conjunction with the present apparatus.

To assist with alignment of the pallets during stacking, each guide arm preferably comprises a leading inside edge (i.e. the edge closest to the pallet) that is tapered or chamfered to guide the pallet into the space between the guide arms. In this way, the apparatus may more easily engage with a pallet, while correcting the lateral position and orientation of the pallet relative to the guide arms. As a result, the eventual stack of pallets are found to be more stable and less likely to topple, as opposed to those formed by conventional stacking techniques,

The apparatus may further comprise a sensor located within the spaced defined by the guide arms. In preferred embodiments, the sensor is disposed at the rear of the space defined by the guide arms and is operable to detect and confirm that a pallet has been correctly engaged by and received into the apparatus.

The sensor may be any suitable pressure or light sensor etc.

To further assist with alignment and positioning of a pallet, the apparatus may also comprise a camera, such as a CCTV camera or similar, which is preferably disposed between the guide arms to help an operator locate and align the pallet prior to and during stacking, A display device, for example a LCD, TFT or other monitor, may be included in the apparatus to view the pictures from the camera. Alternatively, the pictures or video stream may be transmitted wirelessly to a hand-held monitor or smart phone etc.

In other preferred embodiments, the apparatus may also comprise an automatic tying mechanism to secure the stacked pallets together. The typing mechanism may comprise a strapping means that is arranged to pass strapping over the top of the stack and to preferably secure the strap on the underside of the stack etc. In one embodiment, the strapping means comprises a polypropylene strapping that is looped over the stack and is welded on the underside to tightly bind the pallets together. In this way, the risk of the stack toppling or tipping is yet further reduced, which increases safety for the operator and other individuals in the work environment. It is to be appreciated that none of the embodiments described in relation to the present invention are mutually exclusive, and therefore the features and functionality of one embodiment may be used interchangeably or additionally with the features and functionality of any other embodiment without limitation.

Embodiments of the present invention will now be described in detail by way of example and with reference to the accompanying drawings in which:

Figure 1 - shows a perspective view of a pallet stacking apparatus according to a particularly preferred embodiment of the present invention:

Figure 2 - shows a perspective view of an example guide arm together with an example pallet;

Figure 3 - shows a different perspective view of the example guide arm of Figure 2 together with an example pallet; Figure 4 - shows a top plan view of the example guide arm of

Figure 2;

Figure 5 - shows a front cross-sectional view of part of an example apparatus according a preferred embodiment of the present invention at the start of an example stacking operation;

Figures 6 & 7 - show the apparatus of Figure 5 during subsequent stages of the example stacking operation; Figure 8 - shows the apparatus of Figure 5 during a final stage of the example stacking operation; Figures 9a~9d - show an example collating and stacking operation according to a preferred embodiment;

Figures 10a-10d - show the action of an example guide arm during a preferred stacking operation.

Referring to Figure 1 , there is a shown a particularly preferred embodiment of a pallet stacking apparatus 20 according to the present invention. The apparatus 20 comprises first and second guide arms 22a, 22b coupled to a main body 24. The guide arms 22a, 22b define a pallet receiving space 26 therebetween to receive pallets 50 (or pallet bases) of a type as shown by example in Figure 1.

The 'pallet receiving space' is essentially a box-like volume into which pallets 50 may be received and stacked by the apparatus 20, as will be discussed in more detail below.

The apparatus 20 farther comprises a motor (not shown) and a lifting mechanism comprising an engaging means 28, the engaging means 28 being releasably engageable with an opening 50a on the side of the pallet 50.

As shown in Figure 1 , the first and second guide arms 22a, 22b are in the form of erect side walls (or effectively 'side cheeks') in which is mounted the reversibly, vertically translatable engaging means 28. In the example of Figure 1 , the spacing or gap between the guide arms 22a, 22b is fixed, but in other versions of the apparatus the spacing between the guide arms 22a, 22b may be adjustable to accommodate different sizes of pallet. It is to be appreciated that the apparatus of the present invention 20 may be fabricated from scratch from bespoke components or alternatively may be constructed by modifying an existing pallet truck or trolley type jack. Therefore, in some examples it may also be possible to essentially retro-fit a pallet truck according to the prescription of the present invention.

Referring now to Figures 2 to 4, there is shown an example of a simplified guide arm 22b for use with the present apparatus. (It is to be appreciated that the opposite guide arm 22a is a mirror image of the guide arm 22b, and therefore its functionality and form are correspondingly equivalent). As shown in these examples, and with reference to Figure 1 , the guide arm 22b is formed by mounting the side walls on the main body 24. Forks 32 and wheels 34 are each mounted within the guide arm 22b to provide balance for the apparatus and to provide a mounting point for the lifting mechanism. (In examples where the apparatus is formed by modifying a pallet truck, the existing forks are removed in favour of new forks 32 and wheels 34).

The engaging means 28 of the lifting mechanism in each guide arm comprise a pair of retractable latches (as best shown in Figures 5 to 8). Each latch 28 is pivotally mounted and arranged to engage with a respective opening 50a in the side of pallet 50. A shown in Figures 5 to 8, each latch is a 'wedge-shaped' protrusion comprising a flat planar upper surface for engaging with the underside of the top surface layer of the pallet 50.

Referring to Figures 4 & 5, the two pairs of latches 28 are mounted on a lift bar 27 that is guided by linear mechanisms fixed to the forks 32. The motor is operable to vertical translate the lift bar 27 in a vertical plane to thereby controllably raise and lower the latches 28 (as discussed in more detail below). The lift bar 27 can be moved in various ways. In the example shown, a pair of transmission chains 36 attach to the lift bars 27 and to an inner face of the guide arms 22a, 22b. Each chain 36 passes over two shaft mounted sprockets 38 that are carried on a shaft by bearings, which are in turn mounted on a support structure fixed to the forks 32. Each bearing is typically a self-aligning 'sealed for life' bearing unit.

The forks 32 are lifted up and down by an eccentric mechanism, which may, in the case of a modification to a pallet truck, be an extension of the torsion bar that passes through the width of the truck, A hydraulic actuator can be used to rotate the eccentric mechanism. The lift motion through the sprocket gives a 2: 1 mechanical advantage, which enables the latches 28 to have more than sufficient movement to perform stacking of the pallets.

An example stacking operation will now be described with reference to Figures 5 to 8 and 9a-9d & l Oa- l Od.

As shown in Figure 9a, this depicts a typical scene as encountered in many working environments. A plurality of discarded pallets 50 are strewn randomly across a floor surface of the working environment. An operator (not shown) will manoeuvre the apparatus 20, under the action of its own motive force, via the steering handle 30 so as approximately align the apparatus with the first pallet 50} .

The first pallet 50i is then received into the space 26 defined by the first and second guide arms 22a, 22b, as shown in Figures 5 and 10a. The tapered surface of each guide arm 22a, 22b allows for easy and accurate alignment of the pallet 50i, as this ensures the pallet is received into the space 26 in the correct orientation, without any rotation relative to the guide arms 22a, 22b. In this way, an aligned stable stack of pallets can be built up.

Referring to Figure 5, a fixed stop (not shown) at the bottom of the travel of the latches 28 is provided, which reversibly locks the latches 28 in a substantially vertical orientation so that the first (and subsequent) pallet 50i can be received into the space 26 defined by the guide arms 22a, 22b. Each latch 28 is biased towards a substantially horizontal orientation, namely substantially parallel to the floor surface and to the plane of the pallet 50] . This biasing may be achieved by way of a spring or spring mechanism, but may alternatively or additionally be accomplished by action of the latch's own weight, such that it can pivot under the action of gravity into a horizontal orientation. In this way, each latch 28 is able to self-position or self-deploy when it is in the vicinity of a respective opening 50a on the side of the pallet. Once the fixed stop is released by the operator, which can be done by manually releasing a lock or via an electric or hydraulic actuator, the two pairs of latches 28 automatically pivot and engage the underside of the top surface of the pallet 50i, as shown by the ghost lining in Figure 6. To perform the stacking operation, the operator activates the lifting mechanism to raise the lift bars 27 via the chain and sprocket mechanism. This has the effect of driving the two pairs of latches 28 upwardly in a vertical plane between the two guide arms 22a, 22b. As a result, the first pallet 5()i is then raised to a first stacking position (see Figures 7 and 10b) above the floor surface, which in turn vacates the space immediately below the first pallet 50j between the first and second guide arms 22a, 22b.

During or subsequently following the elevation of the first pallet 50_s, a second pallet 50₂ may then be received into the spaced vacated by the first elevated pallet 50i (see Figure 10b). To continue with the stacking operation, the engaging means are operable to then release the first pallet 50i on top of the second pallet 50₂. This is accomplished by the lower surfaces of the latches 28 each having a tapered surface, which acts to tilt the latches 28 into a substantially vertical orientation as these brush against the sides of the pallets 50_{l 5} 50₂ as the lift bars 27 are lowered to their original positions by the operator. Therefore, as shown in Figure 8 (which shows two sets of pairs of latches for illustration only), as the latches 28 descend they move from a horizontal orientation to a substantially vertical orientation, whereupon the fixed stop engages to hold the latches in the vertical orientation. The operator may then release the latches 28 so that they again deploy and engage the second pallet and 50? (in the manner of Figure 6), so that both the first and second pa!Sets 50_{i 5} 50₂ may then be elevated (with the second pallet 5G₂ now occupying the first stacking position and the first pallet 50j occupying a second, higher stacking position - see Figure 10e) and thereby vacating the space immediately beneath the second pallet 5()₂ and between the guide arms 22a, 22b.

As will be appreciated, by repeated application of the above stacking operation it then becomes possible to build up a stack of pallets to any required height and comprising any desired number of pallets. Once the required stack height or pallet number has been achieved, the resulting aligned and stable stack may then be released from the apparatus, by simply lowering the lift bars 27 and allowing the latches 28 to return to their original (fixed stop) positions (see Figures 8 & l Od); whereupon the apparatus can be 'hacked away' from the stack as shown in Figure 9d.

Many variations and modifications are within the scope of the present invention and therefore the foregoing is just one example of a pallet stacking apparatus, which could be implemented according to the prescription of the invention. indeed, referring again to Figure 1 , a sensor 29 can be located within the spaced 26 defined by the guide arms 22a, 22b. As shown, the sensor 29 is disposed on the body 24 of the apparatus and is operable to detect and confirm that a pallet 50 has been correctly engaged by and received into the apparatus 20. The sensor may be any suitable pressure or light sensor etc. To further assist with alignment and positioning of a pallet 50, the apparatus 20 may also comprise a camera 31 , such as a CCTV camera or similar, which as shown in Figure 1 is disposed between the guide arms 22a, 22b to help an operator locate and align the pallet 50 prior to and during stacking. A display device, for example a LCD, TFT or other monitor (not shown), may be included on the body 24 of the apparatus 20 to view the pictures from the camera 31. Alternatively, the pictures or video stream may be transmitted wirelessly to a hand-held monitor or smart phone etc.

Although not shown in any of the figures, the apparatus may also comprise an automatic tying mechanism to secure the stacked pallets together. The typing mechanism may comprise a strapping means that is arranged to pass strapping over the top of the stack and to preferably secure the strap on the underside of the stack etc. In one example, the strapping means comprises a polypropylene strapping that is looped over the stack and is welded on the underside to tightly bind the pallets together. In this way, the risk of the stack toppling or tipping is yet further reduced, which increases safety for the operator and other individuals in the work environment.

Even though the present invention has been described in relation to an apparatus that is operated by a human operator, it is to be understood that a fully automated version of the apparatus could also implemented, in which the apparatus is able, under the action of its own motive force, to search and locate discarded pallets in a working environment and to carry out automatic stacking operations. In such an example, an onboard computer would be programmed to recognise pallets via one or more cameras and to safely collate and stack the pallets into a desired stack height etc. As will be appreciated from the foregoing embodiments, the present invention is able to provide a safe and reliable solution to the problem of stacking pallets in a work and/or storage environment. However, it will be recognised that one or more of the principles of the invention may extend to other stacking applications, where it is necessary to have a mobile apparatus that can collate and stack support structures and/or packaging bases etc,

The above embodiments are described by way of example only. Many variations are possible without departing from the invention.

Claims

1. A pallet stacking apparatus, comprising:

a motor;

first and second guide arms defining a pallet receiving space therebetween;

a lifting mechanism operably connected to the motor and comprising:

an engaging means arranged to be releasably engageable with a side of a pallet,

2. The pallet stacking apparatus of Claim 1 , wherein the engaging means are further operable to release the first pallet on top of the second pallet.

3 , The pallet stacking apparatus of Claim 2, wherein the engaging means are further operable to releasably engage the second pallet and to elevate the second pallet to the first stacking position and the first pallet to a second higher stacking position.

4, The pallet stacking apparatus of any preceding claim, wherein the engaging means comprise at least one retractable latch pivotally mounted in each guide arm and arranged to engage a respective side of a pallet.

5. The pallet stacking apparatus of Claim 4, wherein each latch is biased towards a substantially horizontal orientation.

6. The pallet stacking apparatus of Claim 4 or Claim 5, wherein each latch has a tapered surface operable to tilt the latch into a substantially vertical orientation as the engaging means moves towards a floor surface.

7, The pallet stacking apparatus of any preceding claim, wherein the lifting mechanism is operably connected to the motor via a geared mechanism or flexible linkage.

8. The pallet stacking apparatus of any preceding claim, wherein the motor is further operable to provide a controllable motive force to the apparatus, enabling the apparatus to be translated across a floor surface.

9. The pallet stacking apparatus of any preceding claim, further comprising a set of wheels or rollers.

10. The pallet stacking apparatus of any preceding claim, wherein a leading inside edge of each guide arm is tapered to assist with alignment of the pallet.

1 1. The pallet stacking apparatus of any preceding claim, further comprising a sensor to detect engagement with the pallet.

12. The pallet stacking apparatus of any preceding claim, further comprising means to vary the spacing between the guide arms to accommodate different sizes of pallet,

13. The pallet stacking apparatus of any preceding claim, further comprising a camera disposed between the guide arms to assist with alignment and positioning of the pallet.

14. The pallet stacking apparatus of any preceding claim, further comprising an automatic tying mechanism to secure the stacked pallets together.

15. A pallet stacking apparatus substantially as hereinbefore described with reference to Figures 1 to 10 of the accompanying drawings.