WO2004056217A1

WO2004056217A1 - Apparatus and method for splitting parcels of tobacco into slices

Info

Publication number: WO2004056217A1
Application number: PCT/EP2003/014745
Authority: WO
Inventors: Otto Virag; Kwang Ho Cho
Original assignee: Philip Morris Products S.A.
Priority date: 2002-12-20
Filing date: 2003-12-22
Publication date: 2004-07-08
Also published as: AU2003303184A1

Abstract

The apparatus for splitting tobacco parcels into slices comprises a main conveyor having an inlet end and an outlet end and a rotating splitter head (42) positioned at the outlet end of the main conveyor and having a shaft (44) from which a number of splitting assemblies (46) extend, each splitting assembly (46) including a support arm (48) and splitting means at the outer end of the support arm (48). The splitting means include a splitter bar (50) extending in the rotational direction of the splitter head (42) and having at its forward end a gripper (52) having a sharp edge.

Description

Apparatus and method for splitting parcels of tobacco into slices

Description The invention relates to an apparatus and a method for splitting parcels of tobacco into slices. The Apparatus comprises a main conveyor having an inlet end and an outlet end and a rotating splitter head positioned at the outlet end of the main conveyor and having a shaft from which a number of splitting assemblies extend, each splitting assembly including a support arm and splitting means at the outer end of the support arm.

Tobacco is supplied to cigarette manufacturers in the form of parcels or bales. These parcels are usually layered due to the tobacco leaves having been laid flat one on top of the other and subsequently compressed and will be separated into slices prior to conditioning of the tobacco in continuous conditioning cylinders. The problem with separating out these parcels is that considerable degradation of the tobacco leaves often results.

EP-A-0 244 138 discloses a rotary tobacco splitter as outlined above, wherein one or two rotatable splitting assemblies can be provided at the separating location. One splitting assembly is arranged below the layered parcel of tobacco and the other above the parcel in the embodiment with two rotatable splitting assemblies. The rotatable splitting assemblies may be driven at any speed greater than that of the conveyor or not driven at all. Each splitting assembly comprises a plurality of tines. Two designs are disclosed for the tines: the tines are continuously curved in the first design and angled in the second. The tines have an inner radial part and an outer part arranged at an angle of about 45° to the radius in the second design. At least the edge portions of the tobacco lamina are deformed or crushed when separated by the tines . EP-A-1 254 606 discloses an apparatus and method for splitting parcels of tobacco into slices, wherein the axis of the tine assembly is arranged at a distance above the parcel such that the line from the axis of the tine assembly to the entry point forms an angle of between 14 and 24°, preferably about 16°, with the horizontal and by the peripheral speed of the tine assembly being about three to five times the linear speed of the main conveyor. The actual height of each parcel is measured by a vision system before the processing of the parcel and the vertical position of the splitter head is adjusted such that this angle is achieved.

O-02/089614 discloses an apparatus and a method for delami- nating tobacco in the form of slices from a layered parcel. The apparatus comprises conveyor means for delivering a parcel of tobacco to a separating location and a rotatable tine assembly mounted on an axis extending at right angle to the conveyor means and parallel the layering of the parcel. The rotatable tine assembly includes six or more tines which are pointed and profiled to extend in the direction of rotation of the tine assembly and are driven at a speed greater than that of the conveyor means. The tines are adapted to enter the parcel at an entering location in a direction substantially parallel to the layering of the parcel and to accelerate a layer away from the parcel for effecting separation of the layer of tobacco from the parcel. The axis of the tine assembly is arranged at a distance above the parcel such that the line from the axis of the tine assembly to the entering location forms an angle between 14 and 24° with the horizontal and the peripheral speed of the tine assembly is about three to five times the linear speed of the conveyor means.

The problem underlying the invention resides in how to increase the obtainable number of slices per parcel for a given flow rate and to reduce the changeover time between one parcel and the next parcel so as to allow a more consistent tobacco flow rate. This problem is solved according to the invention by the splitting means including a splitter bar extending in the rotational direction of the splitter head and carrying at its forward end a gripper having a sharp edge .

The gripper pinches in-between adjacent layers of the tobacco parcel, thus starting to detach a layer or a slice from the parcel. As the splitter head rotates, the gripper rotates out of the plane of the split, penetrates partially into the detached part of the slice and pulls the slice away from the rest of the parcel .

Preferred embodiments are set forth in the dependent claims.

The process of the invention may be operated in the continuous mode characterized by continuous advancement of the bale and continuous delamination, or in the incremental mode characterized by incremental advancement of the bale and incremental delamination

The apparatus of the invention may comprise one or more splitter heads, for example, one, two, three or four splitter heads. Preferred is a splitter head which comprises one or two, more preferably two splitting means or assemblies.

Preferably, the splitter bar supports a freely rotatable splitter roller, the circumference of the splitter roller extending radially outwardly and radially inwardly beyond the cross section of the splitter bar. Since the splitter has a significantly larger size than the gripper, it exerts a wedging effect and it splits the top of the parcel from the rest of the parcel. Any friction which may pull the parcel due to the force appearing between the parcel and the splitter is eliminated by the splitter being able to rotate freely.

Preferably the splitter arm also extends in the direction opposite to the rotational direction from the support arm and carries a support roll on this part. The circumference of the support roller extends radially outwardly beyond the cross section of the splitter bar. The outer surface of the support arm gives support to the rest of the parcel and, when the support roll enters into the plane of the split, it pushes the parcel backward, thus facilitating splitting throughout the whole length of the layer so that complete split is achieved.

The support arm is shaped such that the distance of its outer surface from the shaft decreases starting from its forward end where the gripper is mounted. The decrease of this distance equals to the travel of the parcel when the splitter head rotates. This means that the distance of the edge of the gripper from the shaft is larger than the distance at the rearward end of the support arm by the travel of the parcel .

The tobacco parcels are transported by a main conveyor and the parcel height is measured and the speed of the main conveyor and of the splitter head are adjusted so that the last slice has the same thickness as the other slices. The tobacco parcels are delivered to the splitting apparatus with horizontal layering and a turnover device or tipper is provided for tipping a parcel of tobacco onto the main conveyor so that the layering is vertical.

Furthermore, using state of the art equipment, it is very difficult to produce thin slices. Slicing irregularly structured bales, such as bales comprising reconstituted tobacco, presents a significant problem for currently used delaminator equipment and processes. The present invention enables the production of thin slices. It is particularly useful to split bales having an irregular structure of lamina layers, such as bales made from reconstituted tobacco, into slices of substantially the same thickness.

Preferably, the tipper is mounted within the main conveyor. The tipper comprises a horizontal shaft from which first and second flaps extend, the flaps including an angle of 90°. The parcels are normally conveyed to the inlet end of the main conveyor with horizontal layering. The tipper turns the parcel through 90° so that their layering is vertical and the parcels can be split into slices. Both, the weighing step (in particular) and the tipping step are optional. The layers in the bale may be vertical, horizontal or other (e.g. C- shaped)

Preferably front and back support means are provided which support the front and back side of the parcels when they have been turned over by the tipper. The front and the back support are angled arms. Their upper end is mounted such that they can be swivelled and their lower end is provided with a freely rotatable roll . The front support it mounted such that is can contact the front face of the parcel before the parcel is tipped and that it follows the front contour of the parcel during tipping. When the parcel has been tipped, the roll of the front support rests on top of the forward end of the parcel .

The back support is arranged such that it contacts the rearward face of the parcel when it has been tipped. It is swivelled such that it moves at the speed of the main conveyor so that it supports the back of the parcel.

For bales comprising C (Cast Leaf) tobacco, whose layers have very little adhesion to one another and therefore tend to slip aside when they are tipped into vertical position, if desired or required, additional support from the two sides may be provided, for example in the form of side plates, to avoid slippage and to achieve maximum support during conveyance and during splitting.

Embodiments which illustrate the present invention, but which should not by any means be construed as a limitation thereof, will now be described with reference to the drawings in more detail, in which:

Fig. 1 is a side view of a splitting apparatus according to the invention; Fig. 2 is a plan view of the apparatus of Fig. 1;

Figs. 3 to 6 illustrate the sequence of steps of the operation of the tipper;

Figs. 7 and 8 represent side views of the splitter head; Figs. 9 to 14 illustrate the various steps of the operation of the splitter head;

Figs. 15 to 23 show a complete sequence of operation for a Half Case or C96 parcel;

Fig. 24 shows the forces exerted on the slice in case of a irregular layer structure of the parcel; and

Fig. 25 presents a side view of a splitter apparatus having a split main conveyor.

Referring to Fig. 1, the delaminating apparatus comprises a tobacco parcel identification section 1, a parcel handling section 2 and a parcel splitting section 3. All three sections are controlled by a controller not shown in the drawings. For the sake of clarity in the drawings only the operative elements of the apparatus are shown, and the frame has been omitted. The motors for driving the various elements have also been omitted.

The bale identification section 1 includes an inlet conveyor 12, a static weighing device 14 and a height measuring device 16 (Fig. 1) . A number of bales or tobacco parcels 10 are delivered by transport means not shown in the drawings to the inlet end of the inlet conveyor 12. Even if the bales 10 delivered to the bale identification section 1 are of the same type, they have slightly different dimensions and weights. The weighing device 14 is, therefore, included in the inlet conveyor 12 and the measured weight is input into a controller not shown. The height h of the bale 10 is measured by the height measuring device 16, which can be a vision system including a charged coupled device (CCD) camera, and the measured height h is conveyed to the controller.

The bales are conveyed by the inlet conveyor 12 after these measurements to the bale handling section 2. The number of slices and the height of a particular parcel may be different after it has been tipped over. If appropriate, the vertical position of. the tine shaft is adjusted accordingly by the control system in place. The bale handling section 2 includes a horizontal main conveyor 18 and a tipper 22.

The main conveyor 18 includes a continuous belt 20 and it forms together with the inlet conveyor 12 practically a continuous conveying surface. The main conveyor 18 can therefore take parcels 10 from the inlet conveyor 12 and transport them to the tipper 22.

The tipper 22 is located at the inlet end of the main conveyor 18 for tipping over parcels 10 having a horizontal layering so that all parcels 10 transported on the main conveyor 18 have a vertical layering. The tipper 22 comprises two first flaps 26 and two second flaps 28. The first and second flaps 26, 28 extend from a swivel axis 30 and the first flaps 26 include an angle of 90° with the second flaps 28. The tipper 22 has got different lengths for its flaps 26, 28. The length of the parcel receiving first flap 26 is equivalent to the dimension of the tobacco parcel 10 which is parallel to the direction of its travel, while the length of the second flaps 28 is smaller than the height of the tobacco parcel 10. Viewed from the top (Fig. 2) the tipper flaps 26, 28 are located on the two sides of the main conveyor 18 and thus take the parcel 10 on the two sides of its bottom when being tipped.

The swivel axis 30 of the tipper 22 is mounted at a distance from the inlet end of the main conveyor 18, the distance being equivalent to about the length of the first flaps 26. In Figure 1, the first flaps 26 extend horizontally towards the inlet end of the main conveyor 18 and slightly below the plane of the upper section of its continuous belts 20 while the second flaps 28 extend vertically upwards. In this position the tipper 22 is ready to receive a parcel 10.

Each parcel 10 is comprised of substantially parallel, stacked layers of tobacco leaves. The parcels 10 are delivered to the bale identification section 1 with horizontal layering and transmitted by the inlet conveyor 12 to the main conveyor 18 and the tipper 22 with such horizontal layering. As soon as the leading edge of the parcel 10 touches the second flaps 28, the first and second flaps 26, 28 are swivelled clockwise (seen in Figure 1) through 90° so that the tipped or turned-over parcel 10 stands on the upper section of the belts 20 of the main conveyor 18 with vertical layering (Fig. 3 to 6) .

The parcels 10 are positioned one at a time by the tipper 22 at a splitting location 40 at the outlet end of the main conveyor 18 below the splitter head 42. The tobacco parcels 10 still have to be conveyed by the main conveyor 18 to the splitting location 40, the distance depending on the size of the tobacco parcel 10. The tipped-over parcel 10 rests on the main conveyor 18 and will be conveyed further by it during the parcel splitting process. Advantageously, the slice 11 is not supported underneath the pinching position point

The parcel splitting section 3 (Fig. 1) comprises front and back supports 32, 34 and a splitter head 42. Front and back parcel support of the parcel 10 is achieved during the whole parcel movement by the use of the front support 32 and the back support 34.

The front support 32 and the back support 34 each comprise an arm 36, 38 which is swivellably mounted at a distance which is greater than the length of the first flaps 26 above the main conveyor 18 in the region between the swivel axis 30 of the tipper 22 and the outlet end of the main conveyor 18. A freely rotatable roll 37, 39 is mounted at the free end of each of the arms 36, 38. As shown in Figure 2, the two flaps 26, 28 of the tipper 22 leave free way for the back support 34 to make return of the tipper 22 possible to the receiving position before the entire parcel 10 is split into slices 11.

The front support 32 provides support for the front side (towards the splitter head 42) of the parcel 10 from the time the parcel 10 is tipped by the tipper 22. The back support 34 will provide support for the back side of the tobacco parcel 10, which represents also the back side of the last slice, until the backside of the parcel 10 gets to the splitting position 40. Figures 3 to 6 show the way how the front support 32 follows the contour of the front side of the parcel 10 providing support to the outer layer of the parcel 10. Once the parcel 10 is completely tipped the front support 32 is resting on the top of the parcel 10. Then the back support 34 moves to provide support for the back of the parcel 10. The back support 34 is driven such that its movement follows the movement of the main conveyor 18, while the front support 32 may be with or without a dedicated driving system, in which case the support from the front is provided by the weight of the front support 32. The back support 34 provides support for the back side of the tobacco parcel 10 from beginning of split till the last slice split and thus for the back side of the last slice, until it gets to the splitting position 40.

The splitter head 42 comprises a shaft 44 and a plurality of splitting assemblies 46 mounted on the shaft 44 (Figs. 7 and 8) . Each splitting assembly 46 comprises a support arm 48 extending from the shaft 44 and a curved splitter bar 50 supported at about the middle of its length by the support arm 48 and extending approximately on a circle line about the shaft 44. The end of the splitter bar 50 pointing in rotational direction carries a gripper 52 which has a sharp edge. At some distance behind the gripper 52 a splitter roller 54 is freely pivotably mounted on the splitter bar 50. The splitter roller 54 has a diameter such that it extends on both sides beyond the contour of the splitter bar 50. Adjacent the trailing end of the splitter bar 50, a support roller 56 is mounted which is also freely rotatable.

The support arm 48 is a strong construction which is capable of transforming the torque from the shaft 44 into a tangential force as to compensate for the resistance of the parcel towards the entry of the splitter roller 54. The outer surface (the one towards the parcel 10) of the splitter bar 50 is forming a curvature. The radius of the curvature is decreasing from the splitter roller 54 towards the support roll 56. The decrease of the radius equals to the travel of the parcel 10 when the splitter head 42 rotates the angle equivalent to the angle between the centerline of the splitter roller 54 and the centerline of the support roller 56. The radius (Rl) of the splitter bar 50 at the edge of the gripper 52 is larger than the radius (R2) at the back end of the support arm 48 (Fig. 8) . Due to the decreasing distance of the splitter bar 50 from the shaft 44 the gripper 52 of one splitting assembly 46 of each pair is more distant from the shaft 44 than the release roll 60 of the other splitting assembly 46 of the same pair. Advantageously, the outer surfaces of the support arm 48 and the split controller 58 are designed such as to facilitate support of the front of the parcel as it is approaching the splitting position and to push the bale during the splitting action.

This means, the distance of the curved splitter bar 50 from the shaft 44 is decreasing from the forward end, where the gripper 52 is mounted, to the trailing end. At the trailing end, a split controller 58 is attached which extends the curved form of the splitter bar 50. The split controller 58 is a leaf spring and a release roll 60 is freely pivotably mounted at its end. The splitter bar 50 and the split controller 58 each extend through about 90° of the circumference so that both together extend through about half of the circumference of the splitter head 42.

The splitting assemblies 46 are mounted pairwise on the shaft 44, the support arms 48 of the splitting assemblies 46 of each pair extending in opposite directions. The splitting assemblies 46 are arranged such that the front supports 32 and the back supports 34 - two of each of them are shown in Figure 2 - can rotate freely in between the splitting assemblies 46 - three of them are shown in Figure 2 - since they are located offset to the splitting assemblies so that they do not interfere. The front supports 32 can rotate freely and can enter in between the splitting assemblies 46 thanks to their position being set in between two splitting assemblies 46.

The splitter head 42 rotates counter clockwise as shown in Figures 7 and 8, with the advancement of the tobacco parcel 10 towards the splitter head 42. Splitting of a slice 11 from the rest of the parcel 10 takes place - as shown in Figures 9 to 14 - in the sequence of pinching (Fig. 9), partial split (Fig. 10), pull and push (Fig. 11), complete split (Fig. 12) and finally drop and release (Figs. 13 and 14).

First the gripper 52 pinches into the tobacco parcel 10, thus starting to detach a slice 11 from the parcel 10. The gripper 52 has a sharp edge, such that it makes penetrating partially into the slice 11 possible. The gripper 52 has the shape of a wedge. Depending on the angle of the wedge it is possible to control the force required to enter between the layers and to minimize the torque exerted onto the rest of the parcel 10. A wedge having a wider angle of which sides are tangential to the splitter roller 54 directs the forces towards the slice being split rather than towards the main conveyor 18.

Then the splitter roller 54 enters in between the detached layers. Since the splitter roller 54 has a significantly larger size than the gripper 52, when viewed from the side, it splits the top of the slice 11 from the rest of the parcel 10 (Fig. 10) . The splitter roller 54 is a free rotating disc, which has a diameter typically between 50 to 150 mm, and a thickness of 20 to 60 mm. Any friction which could pull some tobacco leaves from the parcel 10 due to the force appearing between the parcel 10 and the splitter roller 54 is significantly reduced or eliminated as the splitter roller 54 can rotate freely around its centerline.

As the splitter head 42 rotates, the gripper 52 rotates out of the plane of the split, the plane of the split being parallel to the layers, and penetrates partially into the detached part of the slice 11. The bottom of the parcel 10 is not yet split (Fig.11) . For bales made of reconstituted tobacco, the layers are typically bent, taking approximately the shape of the letter "C".

The splitter head 42 rotates further and the gripper 52 pulls the slice 11 away from the rest of the parcel 10 while the outer surface of the splitter bar 50 gives support to the rest of the parcel 10. When the support roll 56 enters into the plane of split it pushes the parcel 10 backward, thus enhancing splitting throughout the whole length of the layer, achieving complete split (Fig. 12) .

When the slice 11 has been completely detached from the parcel 10, the split controller 58 and the release roll 60 ensure its free drop to the subsequent take off or collecting conveyor 62. It is advantageous to provide sufficient room for the slice 11 when it is about to drop and no obstacles to the movement of the slice 11. Therefore the split controller 58 has been determined to act as a spring, which allows for various slice thicknesses, and the release roll 60 as a freely rotating roll on which the slice 11 can roll down smoothly. Control for the advancement of the slice 11 is achieved by the usage of the split controller 58 when the previous slice has been separated from the parcel 10 and the parcel is advancing towards the next splitting which is to take place by the subsequent gripper 52. The split controller 58 is especially useful when processing loose parcels 10 which have started natural splitting during their conveyance to the splitting position 40. Owing to the spring type split controller, continuous parcel support is achieved throughout the entire process regardless whether the configuration of the layer is regular or irregular.

The split controller 58 is acting as a leaf spring and provides the control for the advancement of the slice 11 when the previous slice has been separated from the parcel 10 and the parcel 10 is advancing towards the next splitting which is to take place by the subsequent gripper 52. The split controller 58 can be adjusted by rotating the split controller fixture so that different levels of support force can be generated towards the slice 11. The split controller 58 is especially useful when processing loose parcels 10 which have started natural splitting during their conveyance to the splitting position 40. Since the split controller 58 is able to spring towards the shaft 44, it makes the change of the slice thickness possible without changing the geometry of the splitting assembly 46.

The release roll 60 is mounted on the split controller 58. The release roll 60 can freely rotate around its centerline. The release roll 60 ensures the smooth release and a free drop of the slice 11 once it has been completely separated from the parcel 10.

The above described splitter head 42 appropriately works not only on parcels 10 with parallel layers but also with parcels that have irregular layer structure, mostly forming the shape of the letter "C" as shown in Figure 24. In the case of such parcels an attack force 81 causes the layer to spring back 80 rather than split. To achieve the proper and controlled splitting of such parcels 10 it is necessary to have the pull and push effect the way it is described above. The splitting position 40 where the gripper 52 pinches into the tobacco layers has been determined relative to correspond to the centerline of the downstream roller of the main conveyor 18, as shown in Figure 8. The significance of the mentioned distance 67 is twofold: it ensures free drop of the slice 11 from the main conveyor 18 to the subsequent slice takeoff device and it reduces slice compression which would occur if the main conveyor was to extend over the point where the gripper 52 pinches into the tobacco parcel. The position of the centerline of the shaft 44 is determined relative to the height of the tobacco parcel 10 when it is tipped into the splitting position 40. The height at shaft centerline is equivalent to the height of the parcel 10 when it is tipped. In this way the movement of the parcel 10 on the main conveyor 18 towards the splitter head 42 is stabilized and controlled.

The described apparatus allows for the processing of different parcels, among them are C48, C96, hogshead, half C48 cases. The weight of the parcels may vary, for example from about 50 kg to about 450 kg. The material in the different parcels can be

Virginia, Burley, Air Cured, Flue Cured, Oriental, Semi Oriental, Reconstituted tobacco, Cast Leaf, pre-blended strips or any other type forming a layered structure when packed. The apparatus is equally capable of processing all the mentioned parcel sizes and tobacco materials provided the hogshead is fed in halves.

C-48 cartons have a dimension of 0.72 m in the direction of lamination and hogsheads have a diameter of 1.2 m so that the height of those parcels is 0.72 m and 1.2 m respectively when lying on the conveyor belt where the lamination is vertical. A hogshead type bale may be processed without splitting it in half provided that the turnover device is located at the length of the hogshead from the point where the gripper 52 pinches into the tobacco parcel. Pre-packaged tobacco other than reconstituted tobacco and pre-blended materials are packed in C-48 cartons. Cast leaf is packed in C-96 cartons which have about half of the height of C-48 cartons .

The operation of the apparatus is as follows: The parcel 10 is conveyed onto the weight and height measuring inlet conveyor 12. Once the height and the weight have been measured the parcel 10 is tipped and, if necessary, conveyed into the splitting position 40. The layers of the parcel 10 are now in vertical direction thus allowing for the gripper 52 to enter into, and the height of the parcel measured previously is now the "length" for the advancement of the parcel 10.

In case of C48 size, the parcel 10 is tipped directly into the split position 40. As shown in Figures 3 to 6, the front surface of the parcel 10 touches the gripper 52 which is not rotating but stopped at a certain position which provides support for the front surface of the first slice 11. Then the back support 34 swivels downwards provide support for the back of the parcel 10. The back support 34 is driven such that its movement follows the movement of the main conveyor 18, while the front support 32 may be with or without a dedicated driving system, in which case the support from the front is provided by the weight of the front support 32. Figures 3 to 6 show also the way how the front support 32 follows the contour of the front side of the parcel 10 providing support to the outer layers of the parcel 10. Once the parcel 10 is completely tipped the front support 32 is resting on the top of the parcel 10. The gap between subsequent C48 cartons is minimized thereby although the position of the tipper swivel axis 30 is fixed.

For half case or C96 parcel Figures 15 to 23 show a complete sequence of tipping and processing. In this sequence the parcel 10 is split into four pieces. When the gripper 52 is about to enter into the parcel 10 for the last split, the asymmetric (first flaps 26 are longer than second flaps 28) parcel tipper 22 is able to tilt back for the receive of the next parcel, see Figure 21. This is possible also because the back support 34 will provide support for the last slice 11 until it gets to the splitting position 40, Figure 22. When the last slice 11 is taken by the gripper 52, which means it cannot fall back to the main conveyor 18, the back support 34 tilts upward clearing the way to the splitter head 42. Simultaneously with the come-back of the back support 34, the main conveyor 18 advances the next parcel 10 to the asymmetric parcel tipper 22 which then tips the parcel 10 into splitting position 40 and the cycle starts again. It is possible to have the back support 34 to return into its receiving position in two ways (Fig. 23) , either it rotates clockwise, indicated with continuous arc arrow, or it rotates counter clockwise, indicated with dashed arc arrow. The latter solution - back support 34 rotates counter clockwise - allows for the possibility of continuous parcel introduction to the splitting position 40 and thus eliminating the "empty time" which is taken by the back support arm 38 when it returns into its receiving position rotating clockwise and blocking the way of the next parcel to the splitter head 42. Accordingly, the time gap between subsequent Half Case or C96 and C48 parcels is also minimized, although the position of the tipper 22 is fixed.

In the case of irregular layer structure, mostly forming the shape of the letter "C" - shown in Figure 24, the attack force 81 causes the layer to spring back 80 rather than split. The elimination of this spring back effect is achieved by providing sufficient distance 67 between the discharge end of the main conveyor 18 and the centerline of the splitter head 42. By this sufficient room is created for the slice 11 when it is about to drop and no obstacles are present in the way of the movement of the slice 11 once it has been completely separated from the parcel 10. The splitter head is located in vertical direction from the main conveyor such as to minimize compression on the tobacco bale during the splitting or slicing action. The proper vertical positioning of the splitter head facilitates the effective "push and pull action" during the splitter head rotation and the splitting of the bale.

In Figures 1 and 2 the main conveyor 18 is one single conveyor whereas in Figure 25, it is split into two separate conveyors, the receiving conveyor 18.1 and the feeding conveyor 18.2 with independent drives . This allows to advance the next parcel from the height and weight measuring inlet conveyor 12 onto the asymmetric parcel tipper 22, by the help of the receiving conveyor 18.1, before the last slice of the previous parcel would have been processed. By doing this the time between the process of the last slice of one parcel and the first slice of the next parcel can be reduced.

In all above cases the movement of the mentioned elements and the massflow of the tobacco may be controlled by an electronic/electrical control system. The massflow of the tobacco is determined by the speed of the main conveyor 18 - or the feeding conveyor 18.2 and the weight of the parcel which is travelling at the same speed, while the thickness of the slices or the number of slices generated from one parcel is defined by the relation of the rotation of the splitter head 42 relative to the travel of the parcel. These two parameters are independently controlled by the control system of the apparatus thus enabling independent control of throughput capacity and slice thickness.

The thickness of the slices may vary from parcel to parcel while massflow is still the same. This possibility is achieved by the spring type construction of the split controller 58. A change of the thickness can be achieved by a simple change of the speed of the main conveyor 18 or the splitter head 42 rotational speed. As long as the relation between these two speeds remain unchanged, the slice thickness will not change.

For example, having a set-up with two grippers 52 on one splitter head 42 and a desire of having eight slices from a C48 parcel (assuming the "length" (L) of the parcel to be 720mm) the shaft 44 has to rotate four times while the parcel completely passes the splitter head 42. This means a travel of 180 mm of the main conveyor movement for one rotation of the splitter head 42.

Since the split controller 58 is of a spring type construction it allows for the set-up of different slice thickness for the different types of tobacco materials without any modification or reformatting of the splitter head 42. The only parameter to adjust is the speed at which the splitter head 42 is rotating.

It is also easy to change the throughput of the apparatus by changing the main conveyor speed and splitter head rotational speed. As long as the relation between these two speeds remains unchanged, the slice thickness will not change. Advantageously, the only parameter to adjust for the desired slicing thickness is the rotational speed of the splitter head. It is important to select and pre-set the proper thickness for the different materials. The thickness of the slices has to be such that will ensure the integrity of the slice when being pulled away from the rest of the parcel. Some materials, such as reconstituted tobacco require thicker slices for a stable process, whereas increased slice thickness for stable process, whereas flue cured, in general, can be processed with thinner slices. List of reference numbers identification section handling section splitting section tobacco parcel, bale slice inlet conveyor weighing device height measuring device main conveyor take off conveyor belt tipper first flaps second flaps swivel axis front support back support arm arm separating location, delamination position splitter head shaft splitting assemblies support arm blade splitter bar gripper splitter roller support roll split controller release roll collecting conveyor distance spring back attack force

Claims

Apparatus for splitting tobacco parcels (10) into slices (11) , comprising a main conveyor (18) having an inlet end and an outlet end and a rotating splitter head (42) positioned at the outlet end of the main conveyor (18) and having a shaft (44) from which a number of splitting assemblies (46) extend, each splitting assembly (46) including a support arm (48) and splitting means at the outer end of the support arm (48) , characterized in that the splitting means include a splitter bar (50) extending in the rotational direction of the splitter head (42) and having at its forward end a gripper (52) having a sharp edge .

Apparatus as claimed in claim 1, wherein the number of splitting assemblies (46) which extend from the shaft (44) is one or two .

Apparatus as claimed in claim 1 or 2 , wherein the splitter bar (50) supports a splitter roller (54) .

Apparatus as claimed in claim 3, wherein the splitter roller (54) is freely rotatable and the circumference of the splitter roller (54) extends radially outwardly and radially inwardly beyond the cross section of the splitter bar (50) .

Apparatus as claimed in any one of claims 1 to 4 , wherein the splitter bar (50) extends also in direction opposite the rotational direction from the support arm (48) and supports a support roller (56) on this trailing part, the circumference of the support roller (56) extending radially outwardly beyond the cross section of the splitter bar (50) .

Apparatus as claimed in any one of the preceding claims, wherein the support arm (48) is curved such that the distance of its outer surface from the shaft (44) decreases starting from its forward end where the gripper (52) is mounted, the decrease of this distance being equal to the travel of the parcel (10) when the splitter head (42) rotates.

7. Apparatus as claimed in any one of the preceding claims, wherein the splitting assemblies (46) are mounted pairwise on the shaft (44), the support arms (48) of each pair extending in opposite directions.

8. Apparatus as claimed in any one of the preceding claims, wherein a split controller (58) is attached at the trailing end of the splitter bar (50) , which is a leaf spring and extends the curved form of the splitter bar (50) .

9. Apparatus as claimed in any one of the preceding claims, wherein a release roll (60) is freely pivotably mounted at the end of the split controller (58) .

10. Apparatus as claimed in any one of the preceding claims, wherein the actual height of each parcel (10) is measured by a vision system before the processing of the parcel (10) and the vertical position of the splitter head (42) is adjusted such that the centerline of its shaft (44) equals to the height (68) of the parcel when it is in the splitting position.

11. Method for splitting a bale (10) of layered tobacco into slices

(11) comprising the steps of: conveying the bale (10) by a main conveyor to a splitting position at the outlet end of the main conveyor (18) ; arranging the shaft (44) of a rotatable splitter head (42) comprising one or two splitting assemblies (46) which include a support arm (48) and a gripper (52) at the outer end of the support arm such that its vertical distance from the main conveyor (18) is substantially the same as the height of the bale (10) ; splitting the bale (10) by the gripper pinching in between adjacent layers of the bale (10) , partially penetrating into the detached part of the slice (11) and pulling the slice (11) away from the rest of the bale (10) by rotating the splitter head (42) .

12. Method for splitting a bale (10) of layered tobacco according to claim 11 wherein the tobacco is reconstituted tobacco.

3. Method for splitting parcels (10) of layered tobacco leaves into slices (11) by means of an apparatus as claimed in any one of claims 1 to 10, comprising the following steps: weighing the parcel (10) and measuring its dimension in the direction of the layering; tipping the parcel (10) such that its layering is vertical; conveying the parcel (10) by a main conveyor (18) to a splitting position (40) at the outlet end of the main conveyor (18) ; arranging the shaft of a rotatable splitter head (42) including a sharp gripper (52) so that its height above the main conveyor (18) equals the dimension of the parcel (10) in the direction of the layering; and splitting the parcel (10) by the gripper (52) pinching in- between adjacent layers of the parcel (10) , thus starting to detach a slice (11) from the parcel (10); and penetrating partially into the detached part of the slice (11) and pulling the slice (11) away from the rest of the parcel (10) by rotating the splitter head (42) , so that the gripper (52) rotates out of the plane of the split.