A CONVEYOR SYSTEM WITH A KNIFE FOR CUTTING FOOD ITEMS INTO SMALLER FOOD ITEMS

Abstract

A conveyor system with a knife for cutting food items into smaller food items includes a first rotatable knife device having a knife blade, and a conveying system for conveying food items to be cut. The rotatable knife device is positioned above a carrying surface of the conveying system with the knife plane of the rotatable knife device extending through a first gap. The rotatable knife device is adapted for cutting a food item into smaller food items while the food item passes the first gap. The shape of the carrying surface around the first gap is concave and essentially follows the knife path of the rotatable knife blade.

Claims

1-16. (canceled)

17. A conveyor system with a knife adapted to cut food items into smaller food items, comprising: a first rotatable knife device comprising a knife blade, and a conveying system for conveying food items to be cut; wherein the rotatable knife device is positioned above a carrying surface of the conveying system with the knife plane of the rotatable knife device extending through a first gap, the rotatable knife device being adapted for cutting a food item into smaller food items while the food item passes the first gap, wherein the shape of the carrying surface around the first gap is concave and essentially follows the knife path of the rotatable knife blade.

18. The conveyor system with a knife according to claim 17, wherein the carrying surface comprises two or more side by side arranged endless belts or cords.

19. The conveyor system with a knife according to claim 17, wherein the a cross-sectional shape of the carrying surface extending accross the conveyor system and perpendicular to the conveying direction is an arc having a center of a circle substantially at the rotational axis of the rotatable knife device.

20. The conveyor system according to claim 17, wherein the cross-sectional shape of the carrying surface extending accross the conveyor system and seen in the direction of the conveyor conveying forms a vertically oriented elliptical section shape such that the shape of the first gap when the first gap forms an angle to the axis perpendicular to the conveying direction can be an arc having a center of a circle substantially at the rotational axis of the rotatable knife device.

21. The conveyor system with a knife according to claim 17, wherein the conveyor system comprises a first and a second conveyor means, where a second end of the first conveyor is positioned adjacent to a first end of the second conveyor means and where the gap is defined by a distance between the second and the first ends.

22. The conveyor system with a knife according to claim 17, wherein the first gap forms an angle to an axis perpendicular to the conveying direction.

23. The conveyor system with a knife according to claim 17, further comprising a second gap positioned downstream in relation to the first gap, wherein the second gap forms an angle in relation to the first gap, and where the conveyor system with a knife further comprises a second rotatable knife device having a knife plane extending through the second gap.

24. The conveyor system with a knife according to claim 23, wherein the angle of the second gap is shifted, in relation to the angle of the first gap, between 70 and 110.

25. The conveyor system with a knife according to claim 17, wherein the first gap is perpendicular to the conveying direction.

26. The conveyor system with a knife according to claim 17, further comprising a first imaging system positioned upstream in relation to the first gap adapted to obtain first image data of incoming food items, and a processor adapted to receive the first image data to create control parameter for controlling the first rotatable knife device.

27. The conveyor system with a knife according to claim 23, further comprising a second imaging system positioned between the first and the second gap adapted to obtain second image data of cut food items, and a processor adapted to receive the second image data to create control parameter for controlling the second rotatable knife device.

28. The conveyor system with a knife according to claim 17, wherein the knife device comprising: an arm, where the knife blade is mounted to one end of the arm, the opposite end of the arm being adapted to be mounted to a driving unit for supplying rotational movement of the arm and thus the knife blade, wherein the knife blade is mounted to the arm such that, while cutting a food item into smaller food items, a cutting edge side of the knife blade engages with the food item under an angle such that the knife blade exerts with a downwardly facing force onto the food item and towards the carrying surface of the conveyor system during the cutting.

29. The conveyor system with a knife according to claim 28, wherein the cutting edge side and the carrying surface or a tangent at the point of contact of the carrying surface around the gap form an acute angle during the cutting.

30. The conveyor system with a knife according to claim 29, wherein the acute angle is adapted to the type and/or the characteristics of the food item and/or the coefficient of friction of the carrying surface such that during cutting, the horizontal force exerted (F.sub.hori) by the knife device onto the food item does not exceed the frictional force between the food item and the carrying surface.

31. The conveyor system with a knife according to claim 17, further comprising a cutting plane adjustment mechanism adapted to tilt the angle of the knife plane compared to vertical by means of adjusting the angular position of the knife device(s).

32. A method of cutting food items into smaller food item using a conveyor system with a knife which comprises: a first rotatable knife device comprising a knife blade, a conveying system for conveying food items to be cut, wherein the rotatable knife device is positioned above a carrying surface of the conveying system with the knife plane of the rotatable knife device extending through a first gap, the rotatable knife device being adapted for cutting a food item into smaller food items while the food item passes the first gap, wherein the shape of the carrying surface around the first gap is concave and essentially follows the knife path of the rotatable knife blade.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Embodiments of the invention will be described, by way of example only, with reference to the drawings, in which

[0055] FIG. 1 shows a conveyor system with a knife according to the present invention adapted to cut food items into smaller food items,

[0056] FIG. 2 depicts graphically an embodiment where a carrying surfaces for carrying food items to be cut comprises a plurality of side by side arranged endless cord belts,

[0057] FIG. 3 shows an embodiment where concave shape of the carrying surface around the first gap is an arc,

[0058] FIG. 4a,b,c depicts graphically the movement of the knife device shown in FIG. 1,

[0059] FIG. 5a,b,c depicts one embodiment of a conveyor system with a knife according to the present invention,

[0060] FIG. 6a,b,c depicts the conveyor system with a knife shown in FIG. 5, but where the system shown here further comprises a spacer or spacer system for separating the smaller food items after the first cutting process from each other, and

[0061] FIGS. 7, 8 and 9 show various forms of a concave carrying surface around the first and/or the second gap to illustrate that the surface essentially follows the knife path of the rotatable knife blade.

DESCRIPTION OF EMBODIMENTS

[0062] FIG. 1 shows a conveyor system with a knife 100 according to the present invention adapted to cut food items into smaller food items. The conveyor system with a knife comprises a first rotatable knife device 104 driven by a driving unit 108, where the knife device comprises a knife blade 106. The conveyor system with a knife further comprises a conveying system for conveying food items to be cut. The conveyor system in this embodiment comprises a first 101 and a second 102 conveyors, where a second end of the first conveyor is positioned adjacent to a first end of the second conveyor and where a first gap 103 is defined by a distance between the second and the first ends.

[0063] As shown, the rotatable knife device 104 is positioned above the first gap 103 extending accross the conveyor system with a knife plane of the rotatable knife device extending through the first gap 103. As will be discussed in more details later, the rotatable knife device is adapted for cutting a food item into smaller food items while the food item passes the first gap, wherein the shape of the carrying surface 101, 102 around the first gap is concave and essentially follows the knife path 107 of the rotatable knife blade 106. As shown here, the knife device 104 is positioned such that a distal end 109 of the knife blade extends through the carrying surface, e.g. some millimeters below the carrying surface.

[0064] The carrying surface may comprise a support surface and two or more side by side arranged endless belts or cords (not shown here) that extend longitudinally along the carrying surface.

[0065] The knife device 104 comprises an arm 105 and a knife blade 106. The arm is preferably made of light weight material such as, but not limited to, carbon fibers and the like.

[0066] The knife blade 106 is mounted to one end of the arm, where the opposite end of the arm is mounted to the driving unit 108 that supplies the rotational movement 107 of the arm and thus the knife blade. As will be discussed in more details later the knife blade 106 is mounted to the arm such that, while cutting a food item into smaller food items, a cutting edge side 110 of the knife blade engages with the food item under an angle such that the knife blade exerts with a downwardly facing force onto the food item and towards the carrying surface of the conveyor system during the cutting.

[0067] FIG. 2 depicts graphically an embodiment where the carrying surfaces 101, 102 comprises a plurality of side by side arranged endless cord belts 201 where as shown here the cord may have a circular cross sectional shapes 202. It is thus easy to arrange the cord belts such that they follow the shape of the support surface.

[0068] FIG. 3 shows an embodiment where the concave shape of the carrying surface around the first gap is an arc 301 having a center of a circle being substantially at the rotational axis of the rotatable knife device 104.

[0069] Shown is also a zoomed up view of the knife device 104, where the angle 301 between a cutting edge side 110 and a tangent to the carrying surface 103 (or at the point of contact of the carrying surface around the gap) is an acute angle during the cutting. In one embodiment, the acute angle is between 10 and 60, preferably between 20 and 30, most preferably around 25.

[0070] The angle 301 is adapted to the type and/or the characteristics of the food item and/or the coefficient of friction of the carrying surface such that during cutting, the horizontal force F.sub.hori exerted by the knife device onto the food item does not exceed the frictional force F.sub.fric between the food item and the carrying surface.

[0071] As an example, in case the food item is boneless chickenleg experiments have shown that a preferred angle is around 25. Assuming that the maximum thickness h of the boneless chickenlegs is as an example 15 mm the length X of the cutting edge side 103 must at least be:

X=(h.sub.max)/sin 25=15 mm/sin 25=35.5 mm.

[0072] Accordingly, a very short knife blade is needed to perform the cutting of such boneless chickenlegs, where the primary part of the knife device is the arm, which as already addressed can be made of any type of light weight material.

[0073] FIG. 4a,b,c depicts graphically the movement of the cutting device 100 shown in FIG. 1 where the carrying surface may be a surface of a single conveyor where the gap 103 may be created via e.g. a bypass loop, or via the two conveyors 101, 102 discussed previously in relation to FIG. 1.

[0074] As shown here, the knife blade 106 exerts with a downwardly pointing force F.sub.down and a horizontal force F.sub.hori as discussed previously in relation to FIG. 3 onto the food product, where the angle between the knife blade and the carrying surface discussed previously is such that the friction force pointing opposite to the horizontal force F.sub.hori is equal so as to prevent side-wise sliding of the food item 401.

[0075] FIG. 5a,b,c shows one embodiment of the conveyor system with a knife according to the present invention where the conveyor system with a knife further comprises a second gap 503 positioned downstream in relation to the first gap or the moving direction of the conveyor system as indicated by arrow 506. The second gap 503 may be defined by means of placing a second end of a second conveyor 502 adjacent to a first end of a third conveyor 504.

[0076] As shown here the second gap forms an angle in relation to the first gap, and where the conveyor system with a knife further comprises a second rotatable knife device 509 arranged above the second gap having a knife plane extending through the second gap 503. The angle of the second gap is shifted, in relation to the angle of the first gap, between 70 and 110, preferably around 90.

[0077] In operation, the food item 401 which may e.g. be a boneless chicken leg is conveyed in a conveying direction 506 at a conveying speed v1. A first imaging system 507 is positioned upstream in relation to the first gap 103 and is adapted to obtain first image data of the food item 401. A processor receives and processes the first image data to create control parameter for controlling the first rotatable knife device 104, where the controlling may include when to initiate the cutting and when to stop the cutting, preferably so as to divide the food item 401 into smaller food items.

[0078] FIG. 5b shows where the food item 401 has been cut into a plurality of smaller food items, in this case a plurality of strips 510 preferably of equal size, by the first knife device 104. The second conveyor 502 in this embodiment moves with the same speed as the first conveyor, i.e. V=v1.

[0079] Between the first gap 103 and the second gap is a second imaging system 508 for obtaining second image data of the cut food item where the processor processes the second image data for creating control commands for the second knife device 509.

[0080] FIG. 5c shows where the strips 510 have undergone a second cutting process by the second knife device 509. If the arrangement of the second gap 503 is 90 compared to the first gap 103 the food item is cut into substantially rectangular pieces 511 of equal size.

[0081] The final food product shown here is accordingly a plurality of substantially rectangular pieces that are placed together as a kind of a single piece.

[0082] FIG. 6a,b,c depicts the conveyor system with a knife shown in FIG. 5, but where the system shown here further comprises a spacer or spacer system for separating the smaller food items after the first cutting process from each other. In this example, the spacer may comprise a speed control unit the controls separately the speed of the first conveyor 501 and the second conveyor 502 such that a space is created between the strips 510 as shown in FIG. 6b.

[0083] As an example, this may be achieved by via stopping and starting the first conveyor during the operation, e.g. after cutting each item, the first conveyor is stopped temporarily, e.g. for a fraction of a second, while the second conveyor 502 is running.

[0084] An additional spacer may also be provided between the first gap 103 and the second gap 503 for further increasing the distance between the strips before undergoing the second cutting process by the second knife device 509. An additional conveyor unit (not shown) may as an example be provided that is placed downstream in relation to the previous conveyor unit (e.g. the second conveyor) that runs at higher speed such that the space between the strips is further increased.

[0085] FIGS. 7, 8 and 9 show various forms of a concave carrying surface 701, 801, 901 around the first and/or the second gap to illustrate that the surface essentially follows the knife path of the rotatable knife blade 106.

[0086] FIG. 7 shows a concave carrying surface 701 with the width w, which concave carrying surface 701 is an arc having the rotational axis 702 of the rotatable knife device 104 as center. As shown, the radius 703 of this arc-shaped concave carrying surface 701 is such that the distal end of the knife blade 106 extends through the arc-shaped carrying surface 701, e.g. some millimeters below the carrying surface. As it will be explained in the following, tolerances for the concave carrying surface can be defined by a first arc A1 having a radius r1 with the rotational axis 702 of the rotatable knife device as center and a second arc A2 having a radius r2 with the rotational axis 702 of the rotatable knife device as center. When a concave carrying surface, e.g. the upper surface of a conveyor belt or the like, is within these arcs, the concave carrying surface will essentially follow the knife path of the rotatable knife blade.

[0087] The radius r2 of the second arc A2 is less than the distance from the rotational axis 702 of the rotatable knife blade 104 to a distal end of the knife blade 106.

[0088] The difference between the radius r2 of the second arc A2 and the distance from the rotational axis of the rotatable knife blade to the distal end of the knife blade may in one embodiment be in the range of 1 to 9 mm, preferably in the range of 3 to 7 mm, most preferably around 5 mm.

[0089] The radius r1 of the first arc A1 may be more than 80% of the radius r2 of the second arc A2. In a further embodiment, the radius r1 of the first arc A1 may be more than 90% of the radius r2 of the second arc A2 and in a more preferred embodiment the radius r1 of the first arc A1 may be more than 94% of the radius r2 of the second arc A2.

[0090] FIG. 8 shows an example where the concave carrying surface 801, which is arc-shaped, but where the center 802 of the arc is moved sidewards. As shown, the concave carrying surface 801 is inside the limits defined by the first A1 and second arc A2.

[0091] FIG. 9 shows a further example where the concave carrying surface 901 is irregularly shaped, e.g. made out of linear parts or the like to form the concave shape. As shown, the concave carrying surface 901 is inside the limits defined by the first A1 and second arc A2.

[0092] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.