AU1357002A - Crate stacking system - Google Patents

Description

P/00/011 28/5/91 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: CRATE STACKING SYSTEM The following statement is a full description of this invention, including the best method of performing it known to us CRATE STACKING SYSTEM FIELD OF THE INVENTION The present invention relates to a system for the safe stacking of crates used for carrying packaged items, such as loaves of bread.

BACKGROUND OF THE INVENTION A number of types of packaged goods, such as bread produced in commercial bakeries, are transported on open crates. The crates may be formed of moulded plastic. Typically, such crates are designed to nest on one another so that they can be stacked onto pallets for relatively simple handling during 10 distribution operations.

oooo For example, the typical method for transporting such crates of packaged .":bread is to place two stacks of twelve crates, side by side, on a "dolly". The dolly is a flat-top trolley, featuring four multi-directional castors on its underside. The eoooo: stacks of crates on this dolly are then manually pushed, or pulled, into position on the transport vehicle.

There are a number of disadvantages to the system described above.

0 0Firstly, the transport vehicles used in the distribution of commercial bakery products are capable of containing stacks of at least 17 crates high. This means that there is a considerable reduction in the efficiency of usage of the available transport space in distribution, if stack height is limited to 12 crates. However, Occupational Health and Safety (OH&S) guidelines prevent the utilisation of crate o stacks in excess of 12 crates high due to the excessive forces required to be exerted by the manual handlers of these stacks during loading and unloading of transport vehicles. It is believed that a significant percentage of all claims for workers compensation in the bakery industry are related to pushing and/or pulling stacks of bread crates on dollies, as described above.

There are also OH&S concerns surrounding the manual stacking of such crates to a level of 12 crates high, in that there is a significant potential risk of injury to workers required to lift individual crates to heights above shoulder level, as typically required when stacking e.g. the 10 th, 1 1 th and 12 th crates into position.

In order to overcome some of these OH&S concerns, some attempt has been made to utilise small, electrically powered and hydraulically operated, forklifts for the movement of such stacks as required in distribution operations, 2 particularly in loading and unloading transport vehicles. However, use of these devices alone does not alleviate the need to lift the highest crates on each stack into position. In addition, stacks of 12 crates tend to be inherently vertically unstable, in that they will tend to tilt in relation to the plane of the floor, or the dolly. Also, where two stacks of crates are contained on a single dolly, the risk of the stacks tilting from the plane of the floor, but in different directions from one another, greatly exacerbates the risk of the stacks toppling unpredictably, which in turn increases to risk of injury to manual handlers of the stacks.

This tendency is of particular concern when utilising forklifts to handle these stacks. In 'picking up' and unloading operations, the fork-lift is required to tilt its load backwards and forwards at angles of up to 120 from the horizontal, as per Australian Standard AS 2359.4. Therefore, it is impractical, and potentially dangerous, to handle stacks of greater than about eight crates in height with a forklift. Further, fork-lift handling does not alleviate the risk of injury to manual operators who are required to lift into place the upper crates of a 12 crate stack.

It is an object of the present invention to maximise the use of space in transport vehicles, when transporting materials stacked in crates, without compromising the safety of the operators who handle such stacks of crates during 0. 0• loading and unloading of said transport vehicles.

SUMMARY OF THE INVENTION According to a first aspect, the present invention provides a method for stacking crates, including the steps of: forming at least two adjacent stacks of mating crates, of a predetermined maximum height; 0 placing a single bridging member atop the stacks so as to connect the stacks; placing further crates atop each stack to a second pre-determined maximum height.

Optionally, more than one bridging member may be incorporated in the stacks between a pre-determined number of crates, depending on the required height and stability of the stacks.

In one embodiment, the present invention provides a stacking system for nesting crates, wherein a predetermined number of such crates are nested one on top of each other in the form of two, or more, stacks of equal height and equal numbers of crates. Over the top of said stacks is placed a spanning member of sufficient dimension that it links the top crate of the aforesaid stacks, when standing adjacent to one another. The spanning member is formed so that the underside of the spanning member nests onto the upper features of all of the aforementioned crates, thereby preventing these crates from moving in relation to one another. Further crates may be nested on top of the spanning member, as the spanning member has an upper surface formed so that it nests securely with the lower surface of the crates placed immediately on top of it, thereby preventing these crates from moving in relation to one another, and in relation to the spanning member. This process may optionally be repeated, thereby building a ~set of multiple stacks of crates, featuring a pre-determined number of interconnections between the stacks at a pre-determined number of heights.

S* The effect of placing the spanning member, or spanning members, in the manner described above, is to effectively connect the multiple stacks at one or more intermediate points of each stack. This greatly enhances the vertical stability of all of the stacks, and greatly reduces the risk of any, or all, of the stacks toppling due to tilting during transport or loading.

A preferred embodiment of the present invention provides a system of stacking crates, as described above, where such crates are adapted to carry packaged bread.

According to a second aspect, the present invention provides a spanning member for use in the stacking of crates, wherein the underneath surface of the spanning member is adapted to nest securely on the upper features of two such crates, when these crates are positioned side by side. The upper surface of said spanning member is also adapted to nest securely with the underneath surface of two such crates, when such crates are placed side by side. The spanning member may be constructed of a suitable plastic material, or may be constructed from steel, or other resilient metal.

It is further preferred that the underside of the spanning member is adapted to receive the tines of a standard forklift truck or pallet jack from at least the front and rear. This allows the stacks of crates to be picked up directly by the forklift or pallet jack, obviating the need for the dolly. This has the advantage of reducing the capital and maintenance cost of the typical set of dollies required by, for example, a commercial bakery. Preferably, the underside of the spanning member is adapted to receive said tines from all four sides.

Preferably, the spanning members are adapted to nest with one another.

A preferred embodiment of this second object of the invention provides a spanning member, as described above, wherein the crates to be nested below and above the spanning member are standard crates adapted to carry packaged bread.

The broadest embodiment of the invention, however, is not limited to the 10 spanning member, or its use, as contemplated above. In effect, the invention resides in resiliently connecting one or more adjacent stacks of crates, by securing together two or more adjacent crates in each stack, at pre-determined positions in the stack, provided such connection prevents said adjacent crates from moving relative to one another in a horizontal plane.

Accordingly, the spanning member need not have the configuration depicted in Figure 2. There are a number of specific configurations that will achieve the same aim, with the proviso that the underside of the spanning member be adapted to allow forklifting. For example, it may consist of a flat square plate, of sufficient dimension to horizontally span any desired number of crate-stacks, with protrusions extending vertically upward and downward from the perimeter of the plate designed so as to fit securely over the top of all the crate- :stacks, thereby preventing the uppermost crates in each stack from moving in relation to one another. Further crates may therefore be securely stacked on top of the plate, and will similarly fit securely within the vertical protrusions, thereby also being prevented from moving in relation to one another. Such protrusions may be positioned to allow the tines of a forklift to fit underneath the spanning member e.g. for lifting into position.

Alternatively, the invention may not require a spanning member per se, to be placed between the crates in the stack. The same effect may be produced by securely attaching together all crates at the same level in multiple adjacent stacks, particularly where the underside of such crates are adapted for lifting with a fork-lift. For example, the use of a clipping or tying mechanism between the facing sides of the adjacent crates will prevent independent horizontal movement between the crates, and therefore between the stacks.

In addition, depending on the geometry of the crates involved, the safe working height of the crates and the fork-lift, and any space limitations, the invention may be put into practice by use of the desired securing means or bridging members at an optional number of points in the stack, and between an optional number of individual crates in the stack.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 depicts a simplified configuration of the crates used in the stacking system embodying the invention.

Figure 2 depicts a simplified configuration of the stacking spanning member, as used in the stacking system embodying the invention.

Figure 3 shows a schematic and simplified drawing of two stacks of crates, sitting in a dolly, in which a spanning member, as described above, has been deployed between the 8 th and 9th crates of the stack in order to stabilise both of the stacks.

Figure 4 is a flowchart that illustrates a method for implementing the stacking system according to the invention.

Figure 5 is a flowchart that illustrates a preferred method for implementing the stacking system according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENT In one embodiment, the present invention provides a stacking system for nesting plastic crates 1, such as those depicted in Figure 1, wherein a predetermined number of such crates are nested one on top of each other in the form of two stacks of equal height and equal numbers of crates. Such crates are typically approximately 690 mm wide, by approximately 600 mm long, by approximately 150 mm deep. The stacks are typically placed so that the 690 mm sides of the crates are directly adjacent one another.

Over the top of said stacks is placed a spanning member 2, as depicted in Figure 2, of sufficient dimension that it links the top crate of both of the aforesaid stacks, when standing side by side. Typically, the spanning member will be approximately 690 mm wide, by approximately 1200 mm long, enabling it to fit directly over the top crates of both of the stacks simultaneously.

6 The spanning member is adapted so that its underside nests onto the upper features of both of the aforementioned crates, thereby preventing these crates from moving in relation to one another. Further crates may be nested on top of the spanning member, as the spanning member has an upper surface formed so that it nests securely with the lower surface of the crates placed immediately on top of it, thereby preventing these crates from moving in relation to one another, and in relation to the spanning member.

The effect of placing the spanning member across the middle of the stacks, in the manner described above, is to connect the two stacks of crates approximately at the mid-point of each stack, as shown in Figure 3. This greatly enhances the vertical stability of both stacks and greatly reduces the risk of either, or both, of the two stacks toppling due to tilting during transport or loading.

The above-described stacking system, embodying the invention, is preferentially effected by applying the procedure described in Figure 4.

Limiting the height of the initial stacks to eight crates, or less, greatly reduces the risk of injury associated with manual stacking outlined above.

*In a further preferred embodiment of the invention, the stacking system is put into operation by applying the procedure described in Figure S• The result of applying the above process to the stacking of crates, is to provide two stack of 16 crates 1 each, mounted on a dolly 3, with a spanning member 2 placed in-between the 8 th and 9 th crates of both of the overall stacks, as depicted in Figure 3. The stabilising presence of the spanning member in this position allows the stack of extended height to be safely maneuvered via a powered forklift without risk of the stacks toppling. The overall height, being equal to up to 17 crates plus the height of the spanning member, also enables the transport vehicles to be filled to the maximum height allowable, thereby providing for better utilisation of the available transport volume.

It will also be appreciated that, due to the adaptation of the underside of the spanning member to receive forklift tines, via slots 4 depicted in Figure 2, the stack may be built directly upon a spanning member sitting on the floor. The slots 4 allow the stack to be transported by a forklift or pallet jack. This obviates the need for a wheeled dolly, with associated reduction in capital and maintenance costs in respect of these dollies.

Claims (8)

1. 2. A stacking system for nesting crates, wherein a predetermined number of such crates are nested one on top of another, in the form of two stacks of equal height and equal numbers of crates; wherein over the top of said stacks is placed a plastic spanning member, of sufficient dimension that it covers the top crate of both of the aforesaid stacks, when standing side by side; the aforementioned spanning member being formed so that the underside of the spanning member nests onto the upper features of both of the aforementioned crates, thereby preventing these crates from moving in relation to one another; and wherein further crates may be nested on top of said spanning member, the spanning i member having an upper surface formed so that it nests securely with the lower surface of the crates placed immediately on top of it, thereby preventing said crates from moving in relation to one another, and in relation to said spanning member.
2. 3. The stacking system of claim 2, when enacted by placing twin stacks of crates of equal height on a pallet or dolly; repeating this process by stacking identical twin stacks of crates onto the top of a spanning member; using a powered fork-lift to place said spanning member, bearing the two stacks of crates, onto and across the top of the uppermost crates in the twin stacks resting on the pallet or dolly; Sutilising said powered forklift to lift the dolly bearing all of the crates into a predetermined position.
3. 4. The stacking system of claim 3, wherein the crates are adapted to carry packaged bread. A spanning member for use in the stacking system of either claim 2 or claim 3, wherein the underneath surface of said spanning member is adapted to nest securely on the upper features of two such crates, when these crates are positioned side by side; the upper surface of said spanning member also being adapted to nest securely with the underneath surface of two such crates, when such crates are placed side by side.
4. 6. The spanning member of claim 5, wherein its underneath surface is adapted to receive the tines of a forklift or pallet jack, such that the spanning member may be lifted by said forklift or pallet jack. 4*
5. 7. The spanning member of claim 6, wherein its underneath surface is adapted to receive the tines of a forklift or pallet jack from all four sides of said spanning member.
6. 8. The spanning member of any of claims 5 to 7, wherein the upper and lower surfaces of said spanning members are adapted to nest on one another.
7. 9. The spanning member of any of claims 5 to 8, wherein the crates to be nested below and above said spanning member are adapted to carry packaged bread. A spanning member substantially as herein described with reference to figures 1 and 2. 9
8. 11. A stack of crates substantially as herein described with reference to figure 3. DATED this 16th day of January 2002 QUALITY BAKERS AUSTRALIA WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA ALH:ES coos .00 0 s* *9 400 .00.9 a so