BACKGROUND OF THE INVENTION

The invention relates to a device for forming a dough portion, and particularly for turning two substantially opposite side edge areas of a dough slice. The invention further relates to a method for turning two substantially opposite side edge areas of a dough slice.

The invention further relates to a device and method for centring a dough portion, and to an assembly for forming a dough portion comprising a centring device and a folding device.

For forming a dough portion, particularly rolling for out a dough portion into a dough slice and subsequently rolling up the dough slice into a dough strand, use is made of a so-called moulder. Such a moulder comprises a small pressure roller and a large counter roller underneath it for rolling out the dough portion and a device situated downstream in process direction for rolling up the dough slice into a dough strand.

After rolling out in the moulder, the dough slice has a round or oval shape which results in a number of drawbacks in the further treatment. On the one hand the thickness of the dough strand varies over the length of the dough strand; the dough strand becomes thinner and thinner towards its ends due to rolling up the round or oval shaped dough slice.

On the other hand the dough strands show a strongly curved end edge. The end edge of the dough strand is the line at the circumference of the dough strand where the end of the dough slice connects to the rolled-up dough strand.

It is an object of the present invention to improve on at least one of these aspects.

SUMMARY OF THE INVENTION

To that end the invention provides a folding device for turning two substantially opposite side edge areas of a dough slice onto a centre area of the dough slice, comprising: a conveying device for conveying the dough slice in a process direction according to a process path, a first and second folding element which are placed substantially opposite each other and on either side of the process path and each form a guide path for guiding a side edge area of the dough slice moving over it for turning at least a part of this side edge area onto the centre area of the dough slice, wherein the first and second folding element are formed and/or placed for at least partially bringing the side edge areas in overlap.

The folding device according to the invention transforms a dough slice having a more or less round or oval shape into a dough slice having two substantially opposite straight sides. As a result the above-mentioned drawbacks of rolling up the round or oval shaped dough slice are diminished. However, when the side edge areas are narrow with respect to the centre area of the dough slice, in other words when the side edge areas are not at least partially overlapping, after rolling up a dough strand is obtained which at the ends is indeed thicker than in the centre.

By using a folding device according to the invention with which the side edge areas can at least partially be brought in overlap, after rolling up a dough strand may be obtained having an advantageous, particularly an almost constant thickness over the length of the dough strand. Moreover said dough strand shows a considerably less curved end edge; the end edge is formed here by a slightly curved line between the ends of the dough strand.

In one embodiment the distance between the folding elements, at least in a direction substantially perpendicular to the process direction, can be adjusted. As a result the width of the side edge areas and the degree of overlap onto the centre of the dough slice can be adjusted and/or optimised. The width of the dough slice with folded side edge areas can thus be adjusted.

In one embodiment the guide path of the first folding element is formed and/or placed for, considered in process direction, turning the side edge area moving over it earlier with respect to the guide path of the second folding element. In this way it can be prevented that the turning of the side edge area by the first folding element interferes with the turning of the side edge area by the second folding element. While operative thus a first side edge area will be turned onto the centre area by the first folding element, after which a second side edge area will be turned by the second folding element, wherein the second side edge area at least partially overlaps the first side edge area. In one embodiment the first folding element, considered in process direction, is placed upstream with respect to the second folding element. Thus the dough slice arrives earlier at the first folding element and the first folding element is able to turn the side edge area earlier than the second folding element is.

In one embodiment the first and second folding element each comprise a guide path having a twisted configuration. Preferably an angle of twist or angle of inclination of at least a part of the first folding element is smaller than the one of the second folding element. In other words the guide path of the first folding element is twisted more than the guide path of the second folding element is, as a result of which the side edge area can be turned by the first folding element over a shorter distance, considered in process direction, than by the second folding element.

Preferably the upstream ends of the first and second folding elements are placed opposite each other, as a result of which the opposite side edge areas of the dough slice arrive substantially simultaneously at both folding elements. As a result a quieter course of the dough slice through the folding device is realised.

In one embodiment the device furthermore comprises an auxiliary conveying device placed at least partially between the first and second folding element, and placed opposite the conveying device for defining a conveying space for the centre area of the dough slice between the conveying device and the auxiliary conveying device. Said auxiliary conveying device preferably is placed at an upstream side of the folding elements, and is thus able to guide the centre area during the transfer of the side edge areas from the conveying device to the folding elements. Preferably the auxiliary conveying device comprises pressure means for exerting a pressing force on the centre area of the dough slice in the conveying space. Because of these pressure means the centre area can be retained better in the conveying space during the transfer of the side edge areas from the conveying device to the folding elements. Said pressure means can be designed in various ways.

On the one hand the auxiliary conveying device's own weight may be utilised as the auxiliary conveying device is placed above the conveying device so as to be movable and when operative is able to at least partially rest on the centre area of the dough slice.

On the other hand the auxiliary conveying device may be spring- suspended with respect to the conveying device, and when operative can at least be partially resting on the centre area of the dough slice.

Finally the auxiliary conveying device may be provided with drive means for moving the auxiliary conveying device, or at least a part thereof, towards the conveying device. In a simple embodiment the drive means comprise a pneumatic drive.

Preferably the auxiliary conveying device when operative, can be driven in a process direction at a higher speed than the conveying device. In this way it can be prevented to a large extent that the dough slice adheres or sticks to the auxiliary conveying device.

In a simple embodiment the auxiliary conveying device and/or the conveying device comprises a belt conveyor.

In one embodiment the guide path comprises a set of rotatable rollers, when considered in process direction, placed in series that are each rotatable about an axis of rotation that is placed substantially perpendicular to the process direction. Preferably the rollers are placed so as to be freely rotatable. Preferably the rollers are cylindrical. Because the side edge areas are guided during the turning over the rollers said side edge areas are subjected to minimal friction and a constant turning and an easy course during turning can be realised.

The angle between guide paths of the first and second folding element and the centre of the conveying device at the upstream end of the folding element is approximately 180 degrees, and said angle, considered in process direction, becomes smaller due to the twisted shape of the guide paths. Preferably an angle between the centre of the conveying device and the axis of rotation of the consecutive rollers in the set becomes smaller step by step, in process direction.

In one embodiment the first and second folding element each at an upstream side, considered in process direction, comprise a ramp surface for supplying the side edge areas of the dough slice to the set of rotatable rollers. This ramp surface serves to lift the side edge areas to be folded out of the plane of the conveying device.

In order to keep this ramp surface as short as possible and to ensure a proper guidance of the side edge areas, the angle between the centre of the conveying device and the axis of rotation of the roller placed at the upstream side of the set, when considered in process direction, exceeds 90 degrees. The set of rotatable rollers placed in series here preferably form a guide path for guiding the side edge areas over an angle exceeding 90 degrees.

Preferably the set of rotatable rollers placed in series form a guide path for guiding the side edge areas through a vertical. The angle over which the side edge areas are guided by the guide path is such that the side edge areas cannot fall back into their initial position. Preferably the folding elements do not fully fold the side edge areas and a press-on roller is placed downstream behind the folding elements which folds and presses the side edge areas onto the centre area of the dough slice. An advantage of folding the dough slice by the press-on roller is that said press-on roller pushes out air that might be between the dough slice to be folded, along the upstream side of the dough slice, so that no air can be enclosed between the folded dough slice.

Preferably the press-on roller placed directly after the folding elements, at a slight distance, considered in process direction, from the folding elements. As a result the press-on roller is able to ensure the last stroke when folding the side edge areas.

According to a second aspect the invention provides a method for turning two substantially opposite side edge areas of a dough slice onto a centre area of the dough slice, comprising: conveying a dough slice in a process direction by means of a conveying device, guiding the side edge areas of the dough slice over a first and second folding element that are placed substantially opposite each other and along the conveying device and which each form a guide path that guides the side edge area of the dough slice moving over it for turning at least a part of said side edge area onto the centre area of the dough slice, wherein the side edge areas are brought into overlap.

Preferably, considered in process direction, the side edge area of the dough slice moving over the first folding element is at least partially turned earlier than the side edge area of the dough slice moving over the second folding element.

According to a third aspect the invention provides a centring device for centring a dough portion, comprising: a conveying device for conveying the dough portion in a process direction according to a process path, a permanent passage for the dough portion, and a first and second centring element which considered in process direction are placed upstream from the permanent passage and substantially opposite each other and on either side of the process path, wherein the first and second centring elements each comprise one or more rotatable rollers that are each rotatable about a first axis of rotation that is placed substantially perpendicular to the conveying device, and wherein the first axis of rotation of each roller is placed so as to be eccentrically rotatable about a second axis of rotation.

Such a centring device may advantageously be used for supplying a dough portion in a centred manner into a device for forming a dough portion requiring a substantially centred dough portion, such as for instance the folding device described above.

In the folding device described above it is desirable that the supplied dough slice is substantially centred with respect to the folding elements. For this centring the centring device according to the invention may in process direction be placed upstream with respect to the folding device, wherein the permanent passage is aligned with respect to the folding elements of the folding device.

In one embodiment the centring device comprises a drive for driving a rotation of the eccentrically placed rollers about the second axis of rotation. Preferably the rollers are freely rotatable about the first axis of rotation. By driving an eccentric motion of the rollers about the second axis of rotation, the rollers are moved along a circular path. In the part of said path where the rollers are moved to the centre of the conveying device, they are able to take along a dough portion that is out of centre and push it towards the centre.

With respect to the rollers of the second centring element the rollers of the first centring element preferably are rotatable in opposite direction about the first axis of rotation and/or are eccentrically rotatable about the second axis of rotation. Preferably the rollers of the first centring element and the rollers of the second centring element are coupled for carrying out a substantially mirror-symmetrical motion with respect to each other. In other words, two opposite rollers of this embodiment of the centring element will when operative substantially simultaneously traverse the part of the path where the rollers are moved towards the centre of the conveying device. As a result said rollers will not only be able to centre a dough portion, but also, if so desired, at least partially press them together.

Preferably a distance between the second axis of rotation of two opposite rollers of the first and second centring element exceeds a width of the permanent passage.

In one embodiment each of the centring elements comprises a set of rotatable rollers, which considered in process direction, are placed in series. Preferably the distance between the second axis of rotation of two opposite rollers of the first and second centring element becomes smaller step by step considered in process direction. In other words, considered in process direction, the eccentrically rotatable rollers of the first and second centring elements that are placed opposite each other are placed ever more closely together. As a result the dough portion is gradually and in steps brought towards the centre of the permanent passage. In one embodiment the permanent passage comprises two rollers that are placed at a fixed distance from each other and are connected to a drive for driving a rotation of the rollers for defining a passage extending substantially perpendicular to the process direction. Preferably the circumferential speed of the rollers is higher than the speed of the conveying device, preferably 3 to 10 times faster. Due to the difference in speed it can substantially be prevented that the dough portion sticks to the rollers, such sticking may namely deform and/or move the dough portion to an undesirable extent.

Due to the distance between the rollers the width of the dough portion leaving the centring device is further adjusted and/or defined. Preferably the distance between the rollers is adjustable.

In a simple embodiment the rollers are substantially cylindrical.

According to a fourth aspect the invention provides an assembly for supplying a dough slice to a device for forming a dough portion, particularly for rolling out and subsequently rolling up the dough portion into a dough strand, such as for instance a moulder, wherein the assembly comprises: a conveying device for conveying the dough slice in a process direction, and subsequently considered in process direction, a centring device for centring the dough slice, a first press-on roller for between the first press-on roller and the conveying device flattening the dough portion into a dough slice, a folding device for turning two substantially opposite side edge areas of a dough slice onto a centre area of the dough slice, and a second press-on roller for between the second press-on roller and the conveying device pressing the turned side edge areas onto the centre area of the dough slice. Preferably the assembly comprises a folding device as described above. Preferably the assembly comprises a centring device as described above.

Preferably the assembly comprises a first conveying device above which the centring device and the first press-on roller have been placed and a second conveying device above which the folding device and the second press-on roller have been placed. Preferably the assembly is furthermore provided with a pressure roller placed after the second press-on roller for rolling out the folded dough slice. Preferably the speed of the second conveying device is higher than the speed of the first conveying device. Preferably the speed of the pressure roller is larger than the speed of the second conveying device.

The assembly connects to a supply device for supplying a dough portion, for instance a more or less ball-shaped dough portion.

The dough portion is first centred by the centring device and optionally, if the dough portion is wider than the permanent passage of the centring device, made narrower. Thus the dough portions passed through the assembly all have the same width and position after the centring device.

Subsequently said dough portions are flattened by the first press-on roller into an oval disk-shaped dough slice.

The opposite side edge areas of said dough slice are subsequently folded by the folding device onto the centre area of the dough slice, wherein said side edge areas area at least partially brought in overlap. Preferably, considered in process direction, the side edge area of the dough slice moving over the first folding element is at least partially turned earlier than the side edge area of the dough slice moving over the second folding element.

Subsequently the dough slice with turned side edge areas is pressed on by means of the second press-on roller. In this way a turning back of the turned side edge areas, and enclosing air between the turned side edge areas and the centre of the dough slice is at least largely prevented.

The resulting dough slice can subsequently be supplied to for instance a known moulder, wherein the dough slice is rolled out further between a small pressure roller and a large counter roller and subsequently rolled up into a dough strand, which can now be adjusted as regards width.

In one embodiment including a folding device provided with an auxiliary conveying device having a belt conveyor, the first press-on roller forms a circulating roller of the conveyor belt of the auxiliary conveying device. Preferably the first press-on roller comprises a recess over its circumferential surface in which recess the conveyor belt is placed. Preferably the depth and the width of said recess is substantially equal to the thickness and the width, respectively, of the conveyor belt, so that the first press-on roller with conveyor belt defines one closed cylindrical surface for flattening the dough portion. This offers the advantage that the centre area of the dough slice from the moment of flattening onwards can continuously be supported and guided by the auxiliary conveying device.

In one embodiment the first and second press-on roller when operative are driveable at a higher speed at their circumference than the respective conveying device. Preferably when operative the speed at the circumference of the first and second press-on roller is between 5 and 20% higher, preferably 10% higher than the speed of the conveying device with which the dough is conveyed through the assembly. Due to said higher speed it is not only prevented that the dough portion or dough slice adheres or sticks to said first and second press-on roller, but it is also achieved that the dough is at least partially pushed up, as a result of which the resulting dough slice at its downstream side, also referred to as "leading edge", considered in process direction, is stretched and as a result gets a strongly curved edge and at its upstream side, also referred to as "trailing edge", a straighter edge. As the shape of the end edge is at least largely defined by the shape of said trailing edge, a dough strand having a straighter end edge is thus obtained.

The aspects and measures described and/or shown in the application may where possible also be used independent from each other. Said individual aspects of the centring device and folding device as described herein may be the subject of divisional patent applications related thereto.

SHORT DESCRIPTION OF THE FIGURES

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

Figure 1 shows a view of an exemplary embodiment of an assembly for supplying a dough slice to a device for forming a dough portion, in particular a moulder;

Figure 2 shows a view of the centring device of the assembly of figure 1 ;

Figure 3 shows a view of the first press-on roller and the folding device of the assembly of figure 1 ; Figure 4 shows a view of the second press-on roller and a part of the folding device of the assembly of figure 1 ;

Figures 5 and 6 show a view of an exemplary embodiment of the folding device including the auxiliary conveying device according to the invention; and

Figure 7 shows a view of the folding device of figures 5 and 6 with the first and second press-on rollers.

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 shows a top view of an exemplary embodiment of an assembly 1 according to the invention. The assembly comprises a centring device 2 having a permanent passage 21 , a first press-on roller 3, a folding device 4 having a first folding element 41 and a second folding element 42, and a second press-on roller 5. All these elements have been placed on one conveying device in the form of a belt conveyor 6.

Downstream from the second press-on roller 5 the resulting dough slice from the assembly 1 is supplied to a further device such as for instance a moulder 7 in this exemplary embodiment. In figure 1 among others a pressure roller 71 of said moulder 7 is visible.

The centring device 2, as shown in detail in figure 2, is provided with two cylindrical rollers 22, 23, which in between them define the permanent passage 21 . The distance between the cylindrical rollers 22, 23 is adjustable in this exemplary embodiment. The position of the permanent passage 21 is also adjustable for aligning the permanent passage with the folding device 4 situated downstream. The cylindrical rollers 22, 23 are placed so as to be rotatable about the cylinder axis, and are driveable in opposite direction with respect to each other. To that end the cylindrical rollers 22, 23 are coupled by means of toothed belts 24 to a drive device 25 placed adjacent to the centring device 2.

At the upstream side of the permanent passage 21 , considered in process direction A, a first centring element 26 and a second centring element 27 extend.

The first and second centring elements 26, 27 are each provided with two rotatable rollers 261 , 262, 271 , 272 that are each driveable in an eccentric rotational motion. To that end said freely rotatable rollers 261 , 262, 271 , 272 are each eccentric to a driven axis 263, 264, 273, 274, which axis by means of toothed belts 28 is coupled to one of the cylindrical rollers 22, 23.

In the present exemplary embodiment the rollers 261 , 262, 271 , 272 and their suspension are substantially similarly shaped. The mutual distance between the driven axes 263, 273 of the two opposite rollers 261 , 271 situated at the upstream side of the centring device 2 is larger than the mutual distance between the driven axes 264, 274 of the two other opposite rollers 262, 272, which in turn is larger than the mutual distance of the axes of rotation of the cylindrical rollers 22, 23. Thus a dough portion may gradually and in steps be pushed to the centre and/or be compressed by the rollers for realising the desired position and width of the dough portion.

After the permanent passage 21 between the cylindrical rollers 22, 23 the first press-on roller 3 is placed as shown in figure 3. Said press-on roller 3 is able to flatten the centred dough portion from the centring device 2 into a dough slice. Subsequently a folding device 4 is placed provided with an auxiliary conveyor 43 placed above the conveyor belt 6. The press-on roller 3 is in this case adapted as upstream circulating roller of the auxiliary belt conveyor 43 and over its circumferential surface is provided with a recess in which the conveyor belt 431 has been placed. The depth and width of said recess is substantially equal to the thickness and the width, respectively, of the conveyor belt 431 .

At the downstream side the auxiliary conveyor belt 43 is provided with a circulating roller 432 that is movable in a direction perpendicular to the plane of the conveyor belt of the belt conveyor 6.

The auxiliary belt conveyor 43 is placed upstream of the folding elements 41 , 42. Said folding elements 41 , 42 will be described in more detail below.

At the downstream side of the folding elements 41 , 42 a second press- on roller 5 is placed for pressing the side edge areas of a dough slice turned by folding elements 41 , 42. Subsequently the downstream circulating roller (not shown) of the belt conveyor 6 is placed at the end of this exemplary embodiment of the assembly 1 .

As shown in figure 4 the assembly 1 forms a supply device for a moulder 7 including pressure roller 71 and a device for rolling up a dough slice 72.

Figures 5, 6 and 7 show the folding elements 41 , 42 of the folding device 4 in detail. Each of the folding elements 41 , 42 according to this exemplary embodiment comprises, considered in process direction A, a first ramp surface 41 1 , 421 for bringing the side edge areas of a dough slice out of the plane of the conveyor belt of the belt conveyor 6. Downstream of each of these ramp surfaces 41 1 , 421 a series of freely rotatably placed rollers 412, 422 (in this example eight) has been placed that form a twisted conveyance path for the side edge areas of a dough slice.

The conveyance path formed by the rollers 412 of a first folding element 41 is rotated in opposite direction to the conveyance path formed by the rollers 422 of a second folding element 42. Said conveyance paths are formed like a part of a helix wherein the angle of twist or angle of inclination of the first folding element 41 is different from, for instance smaller than, the one of the second folding element 42. The conveyance path of both the first folding element 41 and the second folding element 42 guides and/or supports a side edge area of a dough slice from a position wherein an angle between the side edge area and the centre area of the dough slice is at a large angle α, for instance between 170 and 1 55 degrees, up to a position wherein the angle between the side edge area and the centre area of the dough slice is smaller than 90 degrees. Thus said conveyance paths of the folding elements 41 , 42 guide the side edge areas through the vertical.

It will be clear that the exemplary embodiments of the invention described above are intended to illustrate the invention and not to limit the invention. An expert will certainly be capable of designing alternative embodiments that fall within the scope of protection of the attached claims.

In a further development the centring device 2 is provided with an own first belt conveyor and the folding device 4 is provided with an own second belt conveyor. In this case the first and second press-on roller can be placed above the second belt conveyor.

For achieving a dosed supply between the various parts of the assembly, the first belt conveyor of the centring device 2 preferably has another, preferably lower, speed with respect to the second belt conveyor of the folding device 4. For instance the speed of the second belt conveyor is 1 .75 times higher than the speed of the first belt conveyor.

If downstream of the folding device the dough slice is rolled out further, for instance in a moulder 7, its pressure roller 71 is preferably driven at a higher circumferential speed than the speed of the second belt conveyor. For instance the circumferential speed of the pressure roller is three times higher than the speed of the first belt conveyor.

Furthermore the centring device 2 may be provided with a press-on roller, which is placed on the belt conveyor of this centring device 2, and a pressure roller is placed between said press-on roller and the folding device 4 for rolling out the flattened dough slice from the centring device. Preferably said pressure roller is placed above the second belt conveyor.

In addition the folding device and the centring device according to the invention can also advantageously be utilised individually.

(octrooi/175945/des BP/NG 5035)