BACKGROUND OF THE INVENTION

The invention relates to a device and a method for dividing blocks of cheese.

When dividing blocks of cheese it is essential to obtain as many pieces of the same determined weight as possible. In case of circular blocks of cheese a centre core can be removed from the block of cheese in order to cut wedges from the outer ring. A common approach is to cut a square centre core of a fixed dimension for all blocks of cheese to be processed. This means that an integral number of wedges of the determined weight usually cannot be obtained from both the ring extending around the centre core and the centre core. A result is two remnants that do not comply with the determined weight for a wedge.

The sum of the weights of these two remnants may however exceed the determined weight of a wedge. A known solution then is using a tool changer as a result of which cutting tools are available of different dimensions. This results less often in two ^' remnants that do not comply with the required weight.

It is an object of the invention to provide a device and method for dividing blocks of cheese with which per block of cheese at the most one remnant of a weight that differs from the determined weight is obtained. SUMMARY OF THE INVENTION

According to one aspect, the invention provides a dividing device for dividing a block of cheese into pieces, comprising a carrier for the block of cheese and a first cutting device for cutting a rectangular centre core out of the block of cheese borne by the carrier, wherein the rectangular centre core has a square perimeter in the main plane of the block of cheese, wherein the first cutting device is provided with a first stab knife and a second stab knife on an adjustment device, and a displacement device for moving the first stab knife and the second stab knife towards the carrier according to a stabbing motion, wherein the first stab knife and the second stab knife are both provided with two straight blades that are at a right angle to each other in order to form a straight back side edge of the stab knife, wherein the first stab knife and the second stab knife are positioned at a distance from each other, with the back side edges away from each other and parallel to each other, wherein in projection in stab direction the blades are on the sides of a square, with the back side edges at the extreme corners, wherein the straight blades end in a cutting edge oriented towards the carrier, wherein the adjustment device is adapted for adjusting the mutual distance of the first stab knife and the second stab knife, with in the projection in stab direction the preservation of the location of the blades on the sides of a square.

The distance between the stab knives and thus a part of the square perimeter of the centre core can be set per block of cheese by means of the adjustment device. The centre core can be released from the cheese with two stabbing motions per stab knife, wherein the cuts extend from the two extreme corners over a part of the sides of the square. By means of the adjustable distance between the stab knives any wanted square upper dimension of the centre core to be cut out can be obtained. Therefore the stab knives and the adjustment device form a universal tool for taking out the cores of different sizes. Per block of cheese a centre core can be taken out that is exactly large enough for cutting the desired number of wedges of the same determined weight from the ring extending around the centre core, without remnant. The centre core that was taken out can itself also be divided into wedges of the same determined weight, wherein in this case at the most one remnant of a lower weight is left. Of the entire block of cheese one remnant is left at the most.

In one embodiment the adjustment device is adapted for adjusting the mutual distance between the first stab knife and the second stab knife between a first position and a wider second position in which in the projection in stab direction the square has longer sides than in the first position, wherein in the second position calculated from the back side edge the blades have a cutting length that exceeds half the length of the sides of the square. In that way it is effected that in all positions smaller than the second position the centre core is cut loose all around in two stabs of both stab knives.

In one embodiment the adjustment device is provided with a first pillar guided carriage to which the first stab .knife is attached, and a second pillar guided carriage to which the second stab knife is attached, wherein the first carriage and the second carriage can be mutually moved according to a common straight line, and a preferably substantially continuously variable distance adjustment between the first carriage and the second carriage. The pillar guided carriages guarantee in a simple way that the mutual parallel orientation of the stab knives is maintained . In one embodiment thereof the distance adjustment comprises a screw spindle with opposing threads that engages onto the carriages.

In one embodiment the distance adjustment comprises a stepping motor, preferably for rotation of the screw spindle, so that the distance adjustment between the stab knives can be controlled by an electric control.

In one embodiment the first cutting device comprises a reversal device that is adapted for jointly rotating the first stab knife and the second stab knife over a quarter of a turn with respect to the carrier about an axis of rotation that extends symmetrically between the first stab knife and the second stab knife, parallel to the back side edges of the first stab knife and the second stab knife. The reversal device - is able to rotate the stab knives in between two stabbing motions so that the centre core is cut loose all around .

In one embodiment the dividing device comprises a second cutting device for cutting the block of cheese all around over straight, radially oriented cutting lines into wedge-shaped pieces.

According to a second aspect the invention provides a method for dividing blocks of cheese into pieces by means of a dividing device, wherein the dividing device comprises a carrier for the block of cheese, a first cutting device for cutting a rectangular centre core out of the block of cheese borne by the carrier, and a second cutting device for cutting the block of cheese all around over straight, radially oriented cutting lines into wedge-shaped pieces, wherein the rectangular centre core has a square perimeter in the main plane of the block of cheese, wherein the first cutting device is provided with a first stab knife and a second stab knife on an adjustment device, and a displacement device for moving the first stab knife and the second stab knife to the carrier according to a stabbing motion, wherein the first stab knife and the second stab knife are both provided with two straight blades that are at a right angle to each other in order to form a straight back side edge, wherein the first stab knife and the second stab knife are positioned at a distance from each other, with the back side edges away from each other and parallel to each other, wherein in projection in stab direction the blades are on the sides of a square, with the back side edges at the extreme corners, wherein the straight blades end in a cutting edge oriented towards the carrier, wherein the adjustment device is adapted for adjusting the mutual distance of the first stab knife and the second stab knife, with in the projection in stab direction the preservation of the location of the blades on the sides of a square, wherein the first cutting device further comprises a reversal device that is adapted for jointly rotating the first stab knife and the second stab knife over a quarter of a turn with respect to the carrier about an axis of rotation that extends symmetrically between the first stab knife and the second stab knife, parallel to the back side edges of the first stab knife and the second stab knife, wherein the method comprises according to a cutting plan determining the integer amount of wedge-shaped pieces of substantially the same determined weight that can be obtained from the ring extending around the centre core of the block of cheese, determining the required weight of the ring extending around the centre core, per block of cheese weighing the weight of the block of cheese, determining the weight of the centre core to be taken out in order to obtain the required weight of the ring extending around the centre core, determining the square perimeter of the centre core in the main plane of the block of cheese, by means of the adjustment device setting the mutual distance between the first stab knife and the second stab knife in order to bring the cutting edges on the square perimeter, for the fist time stabbing the block of cheese with the first stab knife and second stab knife and retracting the knives again, by means of the reversal device rotating the first stab knife and the second stab knife over a quarter of a turn with respect to the block of cheese, for the second time stabbing the block of cheese with the first stab knife and the second stab knife and retracting the knives again, wherein the first stab knife and the second stab knife partially enter the cuts that were made the first time, taking out the centre core that was cut loose, and by means of the second cutting device all around over straight, radially oriented cutting lines cutting the block of cheese into wedge-shaped pieces of substantially the same weight in order to realise the determined number of wedge-shaped pieces .

In one embodiment the centre core that was taken out is cut into as many wedge-shaped pieces as possible of the same determined weight, wherein per block of cheese at the most a remnant of a weight that is lower than the determined weight is left.

The aspects and measures described in this description and the claims of the application and/or shown in the drawings of this application may where possible also be used individually. Said individual aspects and other aspects may be the subject of divisional patent applications relating thereto. This particularly applies to the measures and aspects that are described per se in the sub claims.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of a number of exemplary embodiments shown in the attached drawings, in which:

Figure 1 shows a schematic isometric view of an embodiment of a dividing device according to the invention for dividing blocks of cheese, provided with a first cutting device for cutting a centre core out of the blocks of cheese;

Figures 2A, 2B and 2C show cross-sections of the first cutting device according to the indicated cutting lines; and

Figures 3A and 3B show examples of cutting centre cores of different dimensions out of the blocks of cheese by means of the first cutting device.

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 schematically shows an embodiment of a dividing device 1 according to the invention. The dividing device 1 comprises a frame 2, a belt conveyor 3 borne by the frame and having two parallel endless conveyor belts 4 with which successive blocks of cheese 101, 102, 103, 104 are passed in conveyance direction A through the dividing device 1, and along the belt conveyor 1 consecutively a measuring device 10, a first cutting device 20 and a second cutting device 60. The dividing device 1 is provided with an electronic control 8 for controlling the various parts of the dividing device 1.

The dividing device 1 is adapted for dividing the blocks of cheese 101, 102, 103, 104 in wedge-shaped pieces 11, 12, wherein in this example the blocks of cheese 101, 102, 103, 104 have a circular circumference and a flat upper side and lower side and in this example are provided with a hard crust which after dividing is situated on the back side of each wedge- shaped piece 11. As will be elucidated below this requires the first cutting device 20 to cut a square centre core 110 from above out of the blocks of cheese 101, 102, 103, 104.

The measuring device 10 comprises a weighing device 11 positioned in between the conveyor belts 4 and borne by the frame 2, with which weighing device the individual weight of each block of cheese 101, 102, 103, 104 is determined accurately in grams, and a height measure that is not shown for measuring the height and thus the thickness of each block of cheese 101, 102, 103, 104.

The first cutting device 20 comprises a support 21 which by means of two parallel first pneumatic cylinders 22 is suspended from the frame 2. By operating the first pneumatic cylinders 22 the support 21 is only able to move up and down in direction B transverse to the main plane of the belt conveyor 3. The support 21 bears a round bearing bush 22 having a centre line S parallel to the upward and downward motion in direction B. The first cutting device 20 comprises a first pillar guide 24 and a second pillar guide 25 that extend in each other's extensions and that at the sides facing each other are connected to a round inner bush 28. The inner bush 28 extends through the round bearing bush 22 and at the upper side is connected to a square upper plate 26. Between the round bearing bush 22 on the one hand and the whole of the pillar guides 24, 25, the inner bush 28 and the square upper plate 26 on the other hand, there are bearing liners 24 as a result of which a clearance-free swing bearing is realised. !

The first cutting device is provided with a beam 30 that is attached to the upper plate 26. By means of a bearing 61 the outer end of the beam 60 is connected to the connecting rod 62 of a second pneumatic cylinder 63 so as to swing. By means of a bearing 34 the second pneumatic cylinder 63 is connected to a suspension rod 65 projecting from the support 21 so as to swing. By operating the second pneumatic cylinder 33 the pillar guides 24 can be reciprocally rotated over exactly 90 degrees about the centre line S in direction C. The first pillar guide 24 and the second pillar guide 25 bear a first carriage 30 and second carriage 31, respectively, at the bottom side. There are bearing liners 32 between the pillar guides 24, 25 and the carriages 30, 31 as a result of which clearance-free slide bearings are realised. At the outer ends that face away from each other the first carriage 30 and the second carriage 31 are provided with anti-clockwise internal thread 33 and clockwise internal thread 34, respectively, in which a spindle 35 is accommodated, which is bearing mounted to the pillar guides 24, 25 and has anti-clockwise external thread 36 and clockwise external thread 37, respectively, at the outer ends. Above the upper plate 26 a stepping motor 40 is positioned of which the drive shaft 41 extends through the inner bush 28. At the outer end of the drive shaft 41 there is a first toothed wheel 42 that meshes at right angles to a second toothed wheel 43 on the spindle 35. By operating the stepping motor 40 the first carriage 30 and the second carriage 31 move synchronously apart or towards each other in rectilinear direction D transverse to the centre line S.

The first cutting device 20 is provided with a first stab knife 50 and a second stab knife 51 that are attached parallel to each other, parallel to the centre line S, under the first carriage 30 and second carriage 31, respectively. The stab knives 50, 51 both comprise two straight blades 52 that are connected to each other at an angle of 90 degrees to form a straight back side edge 53 that extends parallel to the centre line S. At the lower side the blades 52 are provided with a straight cutting edge 54 that is transverse to the back side edge 53. The straight blades 52 are positioned with their back side edges 53 away from each other according to the sides of a sguare, wherein the back side edges 53 form two opposing corners of a notional square. By operating the stepping motor 40 the first stab knife 50 and the second stab knife 51 move symmetrically away from each other or towards each other in direction D, while preserving the location of the cutting edges 54 on a square, wherein the distance between the back side edge 53 of the first stab knife

50 and the centre line S remain equal to the distance between the back side edge 53 of the second stab knife

51 and the centre line S. The back side edges 53 remain oriented parallel to the centre line S.

The second cutting device 60 comprises an anvil 12 positioned between the conveyor belts 4, and borne by the frame 2, which anvil has a straight upper surface that extends parallel to the straight cutting edges 54 of the stab knives 50, 51. In the lowest position of the support 21 the cutting edges 54 press over the full length against the upper surface of the anvil 12.

The second cutting device 60 is adapted for cutting the blocks of cheese 101, 102, 103, 104 into wedge-shaped pieces 11 when the centre core 110 has been removed from it. The cutting device 60 comprises a straight cutting knife 61 that can be moved up and down in direction E from and towards the belt conveyor 3 and is adjustable in direction F to divide the coreless blocks of cheese 101, 102, 103, 104, 105 into wedge- shaped pieces 11 in a number of successive cutting motions .

The control of the belt conveyor 3, the weighing device 11, the first pneumatic cylinders 22, the second pneumatic cylinder 33, the stepping motor 4.0 and the active parts of the second cutting device 60 is carried out by an electric control 8 that among others is provided with a memory.

The dividing device 1 i-s adapted for dividing the blocks of cheese 101, 102, 103, 104 of a determined nominal weight into wedge-shaped pieces 11 of the same final weight that is accurate as regards grams, according to a fixed cutting plan as shown in its entirety for the fourth block of cheese 104. The actual weight of the blocks of cheese 101, 102, 103, 104 usually differs from the nominal weight as a result of which a correction needs to be made. This is done by adjusting the size and thus the weight of the centre core 110 to be cut out per block of cheese 101, 102, 103, 104.

In this example the blocks of cheese 101, 102, 103, 104 have a nominal weight of 10 kilogram and according to the cutting plan sixteen wedge-shaped pieces 11 of exactly 500 gram need to be obtained around the centre core 110 and from the centre core 110 itself at least three wedge-shaped pieces 12 of exactly 500 gram need to be obtained. The weight of the blocks of cheese 101, 102, 103, 104 without the centre core 110 therefore needs to weigh an accurate 8000 gram. The size of the remnant 13 determines whether a last wedge-shaped piece 12 of exactly 500 grams and a final remnant can be obtained from it or whether said remnant 13 has to be discharged as final remnant right away. The operation of the cutting device is as follows:

The belt conveyor 3 is driven in conveyance direction A according to a start-stop manner and the blocks of cheese 101, 102, 103, 104, 105 are placed on the belt conveyor 3 consecutively at fixed intermediate distances.

As shown for the second block of cheese 102, each block of cheese 101, 102, 103, 104 is weighed individually and accurately in grams by the weighing device 11. Additionally the height of each block of cheese 101, 102, 103, 104 is measured individually and accurately in millimetres. For each block of cheese 101, 102, 103, 104 the weight of 8000 grams is subtracted from the actually weighed weight, which 8000 grams of weight is intended for the sixteen wedge- shaped pieces 11 of exactly 500 grams around the centre core 110. The result thereof is the intended weight of the centre core 110 to be removed. From the density of the blocks of cheese 101, 102, 103, 104 that is known beforehand, the volume of the centre core 110 to be removed is calculated. From the height of the blocks of cheese 101, 102, 103, 104 known or measured beforehand, the projected surface and thus the square intended perimeter 111 of the upper surface of the centre core

110 is determined per block of cheese 101, 102, 103, 104 and is stored per block of cheese 101, 102, 103, 104 in the memory of the control.

As shown in figures 1, 2A-2C for the third block of cheese 103, the stepping motor 40 is actuated per block of cheese 101, 102, 103, 104 to bring the position of the stab knives 50, 51 in accordance with the square intended perimeter 111 of the centre core 110 to be taken out. The centre of the circular blocks of cheese 101, 102, 103, 104 ends up straight below the centre line S. Subsequently the first pneumatic cylinders 22 are actuated as a result of which the stab knives 50, 51 make two angular cuts 112 through the blocks of cheese 101, 102, 103, 104, and retract again. Said cuts 112 are situated on the intended perimeter

111 and the blades 52, calculated from the opposing corners 113 of the cuts 112, always extend to at least halfway the length of the straight sides of the intended perimeter 111. Subsequently the second pneumatic cylinder 33 is actuated as a result of which the stab knives are rotated over 90 deqrees about the centre line S, while preserving the mutual distance in direction D. Subsequently the first cylinders 22 are actuated again as a result of which the stab knives 50, 51 stab the block of cheese 103 again. The blades 53 then partially end up in the previous cuts 112 as a result of which the centre core 110 is fully cut loose and taken out. The stab knives 50, 51 stab straight through the block of cheese 101, 102, 103, 104 and with the cutting edges 54 contact the upper surface of the anvil 12. For each block of cheese 101, 102, 103, 104 the stepping motor 40 therefore adjusts the position of the stab knives 50, 51 in accordance with the size of the centre core 110 to be removed. This is schematically shown in figures 3A and 3B.

As shown for the fourth block of cheese 104 the second cutting device 60 subsequently symmetrically divides the coreless blocks of cheese 101, 102, 103, 104 into sixteen wedge-shaped pieces of 500 gram. In this case straight cuts are made transverse to the main plane of the blocks of cheese 101, 102, 103, 104 that are oriented radially from the notional centre of the circular cheeses. The removed core 110, the weight of which is known exactly, is divided into the maximum number of wedge-shaped pieces 12 possible of 500 gram and a final remnant. Of said wedge-shaped pieces 12 the crust can be on the rectangular rear surface or on one of the triangular side surfaces.

The above description is included to illustrate the operation of preferred embodiments of the invention and not to limit the scope of the invention. Starting from the above explanation many variations that fall within the spirit and scope of the present invention will be evident to an expert.