AU2003205026B2

AU2003205026B2 - Biscuit sorting device

Info

Publication number: AU2003205026B2
Application number: AU2003205026A
Authority: AU
Inventors: Colin Anderson; Neil Funston
Original assignee: Nestec SA
Current assignee: Nestec SA
Priority date: 2002-06-27
Filing date: 2003-06-27
Publication date: 2008-02-21
Anticipated expiration: 2023-06-27
Also published as: AU2003205026A1; AU2003205026C1

Description

P001 Section 29 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: BISCUIT SORTING DEVICE The following statement is a full description of this invention, including the best method of performing it known to us: BISCUIT SORTING DEVICE FIELD OF THE INVENTION The present invention relates to handling and deposition of rough-shaped and dimpled biscuits, particularly but not exclusively rice crackers and the like.

BACKGROUND OF THE INVENTION It is known for various applications to deposit a predetermined number of crackers or similar products into a plastic tray structure. For example, in 'cracker and dip' type products it is often desired to place a small, predetermined number of crackers in a receptacle in the tray, the tray also including a small depression filled with another substance such as a dip. Such products are sold as snacks.

However, it is not straightforward to handle products such as rice crackers reliably. The nature of the surface of such products is such that, when they are slid across each other, the rough surfaces tend to cause binding and interlocking between individual crackers. This prevents consistent and uniform movement Moreover, as the surfaces are irregular, each cracker does not occupy a uniform height when stacked. The height occupied by each cracker depends in part on the random interlocking of dimples and raised parts between the crackers.

Conventionally, depositors used for such items operate on an assumption of uniform height for each cracker, in order to 'wipe off the required number of crackers from the bottom of a stack. This approach works reasonably well where there is not a large variation between the height of individual crackers. However, where the height is not uniform, or blistering and indentations on the surface of the crackers is prevalent, adjacent crackers in a stack can become partially interlocked or attached to one another. This encourages a situation where such crackers are not easily 'wiped off' the bottom of the stack, and instead tend to tangle with one another thereby upsetting the environment of the stack, allowing the mechanism to damage the crackers and allowing incorrect numbers of crackers to be deposited.

While advances have been made in the field of cracker deposition, for example by providing mechanisms that are less dependent on the assumption of uniform cracker height, it remains desirable to remove from the handling and packing system any crackers that are misshapen or which exhibit an unacceptably large maximum height. Such crackers will tend to cause difficulties for even the more sophisticated deposition mechanisms. Such difficulties include blockages in the deposition stack and cracker breakage or damage, leading to increased final product wastage and overall reduction in production efficiency.

It is an object of the present invention to provide a mechanism for continuous removal, from a packing stream, of crackers that are likely, due to their maximum height (which may be related either to their overall shape or their degree of surface roughness), to cause operational difficulties for further processing stages.

SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, there is provided a device for accepting or rejecting crackers according to whether their maximum height meets a set maximum height condition, wherein there is provided: a moving surface; a grading bar positioned along said surface, and at a height above said surface that is equal to the maximum cracker height condition, so as to define said maximum height relative to said surface; a means for urging said crackers across said surface towards said grading bar; and receiving means for accepted crackers.

The above-defined arrangement is such that crackers meeting said maximum height condition pass under said grading bar and into said receiving means, whilst other (rejected) crackers are caught by said bar and continue on said moving surface. Thus the out-of-specification crackers are separated from those crackers whose height meets the said maximum height condition.

This is a simple device that allows immediate physical separation of all crackers whose height characteristics will be likely to cause problems during deposition and/or filling operations. The reject crackers can be disposed of, or possibly fed back into the system as a rework stream, as appropriate. This system ensures that only those crackers having a maximum height that will tend to cause fewer problems for subsequent processing steps presented to the subsequent unit operations.

While any suitable method of urging the crackers across the moving surface may be employed, it is preferred that this is accomplished by gravity. In that case, one side of the moving surface would preferably be raised relative to the opposite side. The crackers would be loaded onto the raised side of the moving surface and allowed to slide downwards across the moving surface toward the grading bar.

Of course, the moving surface itself would have to be sufficiently smooth, and the angle of decline of the moving surface would have to be sufficiently steep, in order that the crackers would readily slide across it and underneath the grading bar. To this end it is more preferred that the moving belt is a linked conveyor belt, constructed from high molecular weight polypropylene, and that the angle of decline from the upper side to the lower side of the moving surface is in the range 150 to 200.

A preferred reject conveyor width is in the range 100mm to 200mm, preferably 150mm. Preferred linear belt operating speed is between 20m/min and preferably 25.5m/min.

It is preferred that the grading bar length is between 1000mm and 1400mm, preferably 1200mm.

Where the crackers are rice crackers, the grading bar is preferably set at a height of 6.5mm above the moving surface.

In another aspect of the invention, there is provided a method for accepting or rejecting crackers according to whether their maximum height meets a set maximum height condition, said method including the steps of: loading said crackers on to a surface; providing a means for urging said crackers to move across said surface; providing a physical barrier positioned relative to said surface such that said movement of crackers not meeting said set maximum height condition will be arrested and the movement of crackers meeting said set maximum height condition will not be arrested; collecting said crackers whose movement has been arrested for rejection; and allowing said crackers whose movement has not been arrested to pass to further processing.

Now will be described, by way of a specific, non-limiting example, a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a schematic, cut-away side view of a biscuit-sorting device according to the present invention.

Figure 2 is a schematic, top view of the same embodiment.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT With reference to figures 1 and 2, one implementation of the present invention is described. It will be appreciated that many elements of the embodiment may be substituted with the equivalent mechanical components.

Figure 1 depicts a device according to the present invention that is situated at the end of the main oven conveyer belt 1 of a conventional oven for the cooking of rice crackers. Unsorted rice crackers 2 travel along the top of this belt.

The sorting device consists of an adjustable grading bar 3, an inclined 'reject' conveyer 4, and a 'good product' conveyer 5. The inclined reject conveyer 4 is linked to the oven belt 1 via a chute 6. The grading bar 3 runs approximately parallel with the direction of movement of the reject conveyer 4, and is set at a height above the reject conveyer 4 that is equal to the maximum height allowable for rice crackers proceeding to the subsequent operations. The reject conveyer 4 is preferably arranged at an angle a. from the horizontal of approximately 150 to 200. The material of the chute 6 and of the surface of the conveyer 4 should be reasonably smooth, such that the rice crackers will tend to slide downwards across the conveyer under the force of gravity alone. The chute 6 may be constructed of food-grade stainless steel, while the belt may be a linked conveyor belt, constructed from high molecular weight polypropylene.

In operation, unsorted rice crackers 2 are conveyed along the main oven conveyer 1 to its end. The unsorted rice crackers 2 then fall onto chute 6 and slide down onto the upper surface of the reject conveyer 4. The rice crackers continue to slide downwards across the top of the conveyer 4 and towards the grading bar 3 as they are concurrently borne along in the direction of travel of the conveyer 4. As the gap between the lower edge of the grading bar 3 and the upper surface of the conveyer 4 is set at approximately the maximum height allowable for the rice crackers, those crackers that are within the specification will slide under the grading bar and will be deposited on the good product conveyer These crackers 7 are then transported to the deposition system.

Typically, for rice crackers, the grading bar would be set at a maximum height of 6.5mm above the reject conveyor.

Those crackers whose height is greater than the allowed maximum height will be prevented from passing beneath the grading bar 3. They will instead be carried along in the direction of movement of the reject conveyer 4 towards a suitable receptacle for out-of-specification crackers. Physical separation of the crackers is thereby effected by the sorting device.

Figure 2 also shows the above-described apparatus. In this particular embodiment the reject conveyer and the good product conveyer are shown travelling in different directions. Of course, depending on the location of the further processing unit operations and the waste cracker recovery system, these conveyers may operate in any desired direction.

It will be appreciated that the implementation described is only one of may possible implementations, and that variations and additions are possible within the broad scope of the present invention.

Claims

1. A device for accepting or rejecting crackers according to whether their maximum height meets a set maximum height condition, including: a moving surface; a grading bar positioned along said surface, and at a height above said surface that is equal to the maximum cracker height condition, so as to define said maximum height relative to said surface; a means for urging said crackers across said surface towards said grading bar; and receiving means for accepted crackers.

2. The device of claim 1, wherein the means for urging the crackers across the surface is gravity.

3. The device of claim 2, wherein the moving surface is arranged such that the side of the moving surface which receives said crackers is raised with respect to the position of said grading bar along said surface.

4. The device of claim 3, wherein the angle of decline of the moving surface from the side of the moving surface which receives said crackers, to the position of said grading bar, is in the range from about 150 to about 200. The device of any preceding claim, wherein said moving surface is suitably smooth, thereby to encourage the sliding movement of said crackers across said surface toward the position of said grading bar.

6. The device of claim 5, wherein said moving surface is constructed from high molecular weight polypropylene.

7. The device of any preceding claim, wherein the linear distance along said moving surface from the side of the moving surface which receives said crackers, to the position of said grading bar, is in the range from about 100mm to about 200mm.

8. The device of claim 7, wherein said linear distance is about 150mm.

9. The device of any preceding claim, wherein said moving surface moves at a linear speed of between about 20m/min and The device of claim 9, wherein said linear speed is about 25.5m/min.

11. The device of any preceding claim, wherein the length of said grading bar is between about 1000mm and about 1400mm.

12. The device of claim 11, wherein the length of said grading bar is about 1200mm.

13. The device of any preceding claim, wherein the crackers are rice crackers, and wherein the grading bar is set at a height of about 6.5mm above the moving surface.

14. A method for accepting or rejecting crackers according to whether their maximum height meets a set maximum height condition, said method including the steps of: loading said crackers on to a surface; providing a means for urging said crackers to move across said surface; providing a physical barrier positioned relative to said surface such that said movement of crackers not meeting said set maximum height condition will be arrested and the movement of crackers meeting said set maximum height condition will not be arrested; collecting said crackers whose movement has been arrested for rejection; and allowing said crackers whose movement has not been arrested to pass to further processing. The method of claim 14, wherein the means for urging the crackers across the surface is gravity.

16. The method of claim 15, wherein the surface is arranged such that the side of the surface which receives said crackers is raised with respect to the position of said physical barrier along said surface.

17. The method of claim 16, wherein the angle of decline of the surface from the side of the surface which receives said crackers, to the position of said physical barrier, is in the range from about 150 to about 200.

18. The method of any of claims 14 to 17, wherein said surface is suitably smooth, thereby to encourage the sliding movement of said crackers across said surface toward the position of said physical barrier.

19. The method of claim 18, wherein said surface is constructed from high molecular weight polypropylene. The method of any of claims 14 to 19, wherein the linear distance along said surface from the side of the surface which receives said crackers, to the position of said physical barrier, is in the range from about 100mm to about 200mm.

21. The method of claim 20, wherein said linear distance is about 150mm.

22. The method of any of claims 14 to 21, wherein said surface is a conveyor belt.

23. The method of claim 22, wherein said conveyor belt surface moves at a linear speed of between about 20m/min and

24. The method of claim 23, wherein said linear speed is about 25.5m/min. The method of any of claims 14 to 24, wherein the length of said physical barrier is between about 1000mm and about 1400mm relative to the direction of travel of said conveyor belt.

26. The method of claim 25, wherein the length of said physical barrier is about 1200mm.

27. The method of any of claims 14 to 26, wherein the crackers are rice crackers, and wherein the physical barrier is set at a height of about above the surface.

28. The method of any of claims 14 to 27, wherein said physical barrier is a grading bar. DATED this 27th day of June 2003 GOODMAN FIELDER LTD WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA PNF/ALH