WO2012093933A1

WO2012093933A1 - Conveyor system comprising centring unit and/or rotation unit

Info

Publication number: WO2012093933A1
Application number: PCT/NL2011/050790
Authority: WO
Inventors: Cornelis Franciscus Maria BOOTSMAN; Johannes Adrianus Maria VAN SCHAIK; Ronald Walter Neutel
Original assignee: Roboxis B.V.
Priority date: 2011-01-07
Filing date: 2011-11-18
Publication date: 2012-07-12
Also published as: EP2661337A2; EP2661404A1; WO2012093932A2; WO2012093932A3

Abstract

Method and conveyor system for processing a conveyed product (1) comprising a first and a second stage (1, 11) of centring and rotating the product (1). In the method, products (1) are supplied which are loaded in a random orientation on product carriers (2). In the first stage I the products (1) are displaced to a centre position of the product carriers (2) by the operation of a centring unit (100).

Description

Title: Conveyor system comprising centring unit and/or rotation unit.

The invention relates to a conveyor system and method for processing at least one product in a conveyor system.

A lot of conveyor systems are known from the prior art. Conveyor systems are known for packaging all kind of products. In particular food articles have to be handled carefully. Food articles typically have an amorphous geometry. Further, the food articles need to be handled carefully. A too hard gripping or pressing may damage the food articles which may strongly decrease the storage life of the food articles. Special tooling is available for handling such vulnerable articles, but damages to the products are still a problem. Other problems of the conveyor systems are a low efficiency and reliability. It is desired to improve conveyor systems and in particular food conveyor systems in that an operating time of operating units is decreased and in that the reliability of the operations is increased. In particular it is desired to improve a handling of the products.

The general object of the present invention is to at least partially eliminate the above mentioned drawbacks and/or to provide a useable alternative. More specific, it is an object of the invention to provide an improved conveyor system and method for processing products.

According to the invention, this object is achieved by a method for processing at least one product in a conveyor system according to claim 1 . In the conveying system at least one product is conveyed in a conveying direction. The method according to the invention comprises the steps of providing a product carrier, wherein the product carrier has an upper surface for carrying the product, wherein the carried product is freely movable over the upper surface and wherein the upper surface has a centre position; supplying the product to the upper surface of the product carrier; providing a centring unit for positioning a product on the product carrier at the centre position; and operating the centring unit to displace the product to the centre position of the product carrier.

The centre position may be a target zone or a target area at the upper surface of the product carrier. The target area may have a borderline wherein it is desired to position the product by the centring unit within the borderline, such that the product does not extend over the borderline. The dimensions of the borderline may correspond to a maximum outer contour of a product including some tolerance.

Advantageously, the presence of a centring unit may make the conveyor system less susceptible for interferences, because the position of the products relative to their respective product carriers after passing the centring unit is substantially the same each time. After passing the centring unit, the products may be supplied to downstream positioned operating units in a predetermined position. The operating units may operate in a more efficient manner due to this predetermined position of the products. In particular, the efficiency of grippers may be increased. The reach of grippers may be reduced which may allow a faster conveyor system.

In an embodiment of the method according to the invention, the provided centring unit comprises a vibration unit. The product carrier is vibrated by a vibration unit to force the carried product to the centre position. The generated vibrations may advantageously improve the centring efficiency of the centring unit. Due to the vibrations, random loaded products may get quicker at the centre position of the product carrier.

In an embodiment of the method according to the invention, the product carrier is vibrated and rotated about a vertical axis to force the carried product to the centre position, which vertical axis is positioned at the centre position. The provided centring unit comprises a rotation element for rotating a product carrier. The vibrations may be generated in all directions. The vibrations may be generated in vertical and/or horizontal directions. But, preferably, the vibrations are generated in a horizontal plane. And, more preferably, the generated vibrations are directed in a single direction which is transversal to the conveying direction, alternatively referred to as the conveyance direction. In the case of generating vibrations in a single direction only, the applied rotation of the product carrier may improve the centring efficiency further. The products are more susceptible for the single direction when the vibrations act on the product in a direction towards the centre position. By rotating the product carrier during a centring operation, the product and single direction of the vibrations will get substantially aligned for a certain time interval, during which time interval the product is maximally stimulated to move to the centre position.

In an embodiment of the method according to the invention, the vibration unit generates during a first time interval vibrations with a large amplitude and during a second time interval vibrations with a small amplitude. The first and second time interval may be applied in random order, but preferably the first time interval is applied first such that the large amplitude of the vibrations cause the product to obtain a stable neutral position. In the stable neutral position, the product is less susceptible for rolling or other undesired movements. After the large amplitude vibrations, the product may get accurately positioned by generating the small amplitude vibrations. Herewith, the product may be stable and accurately positioned at the centre position. Prior to the first time interval vibrations, the vibration unit may generate during a third time interval vibrations with a small amplitude. During the third time interval the amplitude of the vibrations may increase gradually until the first time interval is reached where the large amplitude is maintained until the second time interval is reached in which the amplitude of the vibrations gradually decrease to zero. In an embodiment of the method according to the invention, the provided conveyor system is of a continuous type, wherein products are conveyed continuously at a substantially constant velocity. In contrast to a conveyor system having a stop-and-go or incremental, stepwise moving product carrier, the continuously moving products in a conveyor system of the continuous type are less susceptible to undesired displacements.

In an embodiment of the method according to the invention, the method further comprises a step of providing a rotation unit for rotating the product carrier; determining an initial angular orientation of the product on the product carrier; determining a deviation angle which is defined by a deviation of the initial angular orientation from a desired angular orientation; and operating the rotation unit to rotate the product carrier about the deviation angle.

Advantageously, the method herewith comprises a first stage of centring a product to a centre position on the product carrier and further comprises a second stage of rotating the product to a desired angular orientation.

In an embodiment of the method according to the invention, the product carrier is rotated by the rotation unit during a conveying movement of the product carrier by using an occurring relative velocity between the rotation unit and the conveyed product carrier. The product carrier may pass the rotation unit. During the passage of the product carrier the rotation unit may engage to an outer circumference wall portion of the product carrier to rotate the product carrier. Advantageously, by using the relative velocity deducted from the movement of conveying, the rotation unit may have a simple configuration.

In an embodiment of the method according to the invention, the method comprises the step of providing a base carrier which carries at least two product carriers which are arranged in an array, wherein the product carriers are rotatable connected to the base carrier, wherein the base carrier is conveyed together with the product carriers for processing multiple products as a group. The method may operate more efficient when using the base carrier. An obtained position and orientation of a product may be more stable maintained which may improve the efficiency of the process.

Preferably, the method according to the invention is applied in a conveyor system which is arranged to process grouped products. In an embodiment of the conveyor system at least two product carriers are arranged side by side in a direction transversal to the conveying direction, wherein the method comprises the step of aligning side by side arranged carried products. By carrying out the method, the products are accurately positioned and oriented in a preferred angular orientation which may improve the efficiency of later performed operations such as gripping of the products to remove the products from the respective product carriers. In particular, the method may be applied for packaging purposes. Grouped products may have a predefined positioning and orientation which may allow easy gripping of the grouped products with a single gripper. Applying the method according to the invention may result in a simple configuration of the total conveyor system which may reduce investment capital. Further, the invention relates to a conveyor system for processing products, wherein the conveyor system comprises a product carrier, wherein the product carrier has an upper surface for carrying the product, wherein the carried product is freely movable over the upper surface, and wherein the upper surface has a centre position; and a centring unit for centring the carried product on the product carrier such that the product is positioned at the centre position.

Advantageously, the conveyor system is suitable to process products which are susceptible for damages due to applied pressing forces. Such products are for example soft and fresh products like vegetables and fruits. Such products must be handled with care. The product carriers are free from clamping or coupling elements which reduces the risks on damages to the products. The products are freely moveable over the upper surface of the product carrier. Further, this type of product carriers is in particular suitable to be used with amorphous products like paprika's, sweet peppers, bell peppers, capsicums etc.

Advantageously, the presence of the centring unit may result in a more stable and reliable process. The positioning of the products at the centre position of the product carrier may reduce collisions with operating tools, like grippers, of operating units. It may also improve the efficiency and/or speed of subsequent operations, because the products are provided in predetermined positions.

In an embodiment of the conveyor system according to the invention, the upper surface of the product carrier comprises at least one inclined wall portion, wherein the centre position is positioned at a lower region of the upper surface. Advantageously, the product carrier has a self centring property. The centring unit is incorporated in the product carrier. A product may be loaded from above on the upper surface. Due to the inclined wall portion the product will already have a tendency to move to the centre position. This tendency is proportional to the level of inclination, so that the larger the inclination, the better the self centring property. However, a large inclination may interfere with subsequent operations, for instance, a gripper may have problems gripping each and every passing product due to the presence of the large inclination, especially when the size of the products varies a lot. In such a case, the level of inclination is optimised with respect to the subsequent operations, e.g. the reachability of the products by the gripper is ensured while choosing the inclination, preferably the largest possible inclination, of the wall portion.

In an embodiment of the conveyor system according to the invention, the upper surface of the product carrier is at least partially deformable to obtain a temporary inclined wall portion when the upper surface is agitated for forcing the product to the centre position. The product carrier may have a carrier platform made of an elastic material, like rubber. The carrier platform may be tensioned inside a circumferential framework. Advantageously, the product carrier may have a smooth configuration. Edges and corners may be minimised which may reduce the risk on residuals after a cleaning the product carrier.

In an embodiment of the conveyor system according to the invention, the product carrier has at least partially an upstanding upper edge for preventing a product from falling off the product carrier. The upstanding upper edge may be closed or partially open. The upper edge provides an obstacle which may stop a product.

In an embodiment of the conveyor system according to the invention, at least the upper surface of the product carrier is rotatable about a centre axis of the product carrier, wherein the centre axis passes through the centre position. Preferably, the product carrier as a whole is rotatably connected with respect to a conveyor means, in particular with respect to a base carrier. The upper surface including the carried product may be rotated during a centring operation. The rotatable upper surface enables an improved centring efficiency.

In an embodiment of the conveyor system according to the invention, the centring unit comprises a vibration unit for vibrating a product carrier. Advantageously, the presence of the vibration unit positively effects the centring operation. Preferably, the vibration unit is arranged to generate vibrations in a direction transversal to the direction of conveyance.

Preferably, the vibration unit comprises a capture element to engage with the product carrier to vibrate the product carrier. The capture element may be an elongated profile, wherein the product carrier is vibrated by the elongated profile which generates vibrations in a transversal direction.

In an embodiment of the conveyor system according to the invention, the elongated profile is fixedly connected at both ends to a framework. In contrast to a middle region of the profile, the fixed ends of the profile do not or hardly not cause vibrations. As a result, vibrations with a small amplitude are generated at the entrance and exit of the centring unit, and vibrations with a large amplitude are generated halfway the centring unit. Large vibrations forces the carried product into a stable position, and the small vibration brings the product in accurate position. Advantageously, the presence of varying vibrations provide a more stable centring operation.

In an alternative embodiment of the conveyor system according to the invention, the elongated profile may comprise three portions, namely a middle portion connected to an agitator or actuator of the vibration unit to vibrate and two outer portions which are hingeably connected to the framework and the respective end of the middle portion, thereby also providing vibrations with a small amplitude at the entrance and exit of the centring unit and vibrations with a large amplitude halfway the centring unit, but requiring less power as the elongated profile does not have to be deformed in order to have the same effect.

In an embodiment of the conveyor system according to the invention, the centring unit comprises at least one rotation element for engaging and rotating a product carrier during a centring operation.

In a particular embodiment, the rotation element is a guide bar. The guide bar is stationary disposed, such that an engaging product carrier rotates when passing by.

Preferably, the rotation element of the centring element is resiliency disposed. To dispose the rotation element in a resilient manner, the rotation element may be resiliency connected to a framework by at least one spring or may at least partially be made of a resilient material. Herewith, the rotation element of the centring unit may vibrate together with an engaged product carrier. The guide bar may also be connected to the capture element to vibrate along with the product carrier while engaging the product carrier so that resiliency of the guide bar is not necessary.

In an alternative embodiment, the centring unit comprises push means to push a product on a product carrier towards the centre position. The push means may comprise brushes. The brushes may be arranged movable, wherein a product is softly pressed to the centre position. Alternatively, the push means may comprise air jets to push a carried product by an air stream.

In an embodiment of the conveyor system according to the invention, the conveyor system comprises a base carrier for carrying multiple products which base carrier carries at least two product carriers for processing multiple products as a group, wherein the product carriers are rotatable connected to the base carrier. Preferably, the at least two product carriers are disposed in a linear array on top of the base carrier. In particular the base carrier comprises at least three product carriers.

Advantageously, grouped products on the base carrier are accurately positioned which may allow a group wise treatment of the products. The group of products may e.g. be picked up together to pack the grouped products in a package.

In an embodiment of the conveyor system according to the invention, the base carrier comprises an engagement element to obtain an engagement with the centring unit.

Advantageously, the base carrier may be vibrated such that all connected product carriers vibrate together with the base carrier.

In an embodiment of the conveyor system according to the invention, the vibration unit directly operates on the one or more product carriers supported by the base carrier instead of indirectly via the base carrier. The product carriers are therefore preferably moveably supported by the base carrier in order to allow the product carriers to vibrate relative to the base carrier. In case the vibration unit is configured to generate vibrations in a single direction, e.g. a direction transversal to the direction of conveyance, the product carriers are preferably supported by the base carrier such that movement of the product carriers relative to the base carrier is only allowed in said single direction. Such a support arrangement can for instance be obtained using two parallel leaf springs which act as a linear guide. The advantage of leaf springs is that they have a high stiffness in all translation directions except for one. In case of the single direction being a direction transversal to the direction of conveyance, the leaf springs preferably extend from the base carrier in a direction parallel to the direction of conveyance. In case of product carriers are driven directly by a respective vibration unit, the abovementioned engagement element is provided on each product carrier for engagement with respective capture elements of the vibration units.

In an embodiment of the conveyor system according to the invention, the rotation element of the centring unit is mounted on the capture element of the vibration unit. As a result, the rotation element vibrates along with the capture element and thus the product carrier, so that the position of the rotation element relative to the product carrier is not disturbed by the vibrations.

When the vibration unit is configured to vibrate the product carriers in a single direction only, extra measures may be taken in order to suppress or prevent undesired vibrations in other directions. One of these measures may be to properly support the product carriers with stiff elements which only allow movement in one direction, e.g. the parallel leaf springs described above. Another measure may be to use play free support elements. If for instance the product carrier is rotatably supported, e.g. in order to allow rotation during centring, the support elements allowing the rotation of the product carrier are preferably play-free, e.g. play-free ball bearings. Further, the engagement element and capture element can be configured to engage in a play-free manner and/or in statically determinate way with each other to prevent vibrations in other directions then the intended single direction.

In an embodiment of the conveyor system according to the invention, the conveyor system further comprises a rotation unit for rotating a product carrier, which rotation unit is disposed downstream the conveying direction after the centring unit. The conveyor system includes advantageously a first stage of positioning the products on the product carriers and a second stage of orientating the products in a predetermined angular orientation at the product carrier.

In an embodiment of the conveyor system according to the invention, the rotation unit comprises a detector, in particular a camera detector, for detecting an initial orientation including an initial angle of the product carried by the product carrier. The rotation unit further comprises a control unit to determine a deviation angle defined by the difference between the initial angle and a desired angle of a desired orientation.

In an embodiment of the conveyor system according to the invention, the detector of the rotation unit provides 3D information about the product carried by the product carrier which increases the accuracy of determining the initial orientation relative to a detector providing 2D information. For obtaining 3D information, the detector may be a laser scanner, e.g. a laser scanner using the time-of -flight principle or, as preferred, a laser scanner based on triangulation. When using time-of-flight, the time it takes for a light beam to travel to the product and back is measured to measure the distance from the detector to the illuminated spot on the product. When using triangulation, a difference in distance to the detector results in the reflected light beam being projected towards a different location on the detector. The same principles can be used using sound beams instead of light beams. 3D information may further be obtained by mimicking stereopsis using two cameras.

When a laser scanner based on triangulation is used to obtain 3D information about the products, the laser preferably emits a laser line having a length at least as large as the largest possible product that can be handled by the conveyor system, so that information about the product is simultaneously gathered along the line, and the laser source does not necessarily have to be moved. The laser line further preferably emits the laser beam parallel to the dimension that is to be measured to avoid undetectable areas on the product due to obstruction of the laser line as much as possible. The main optical axis of the camera detecting the reflected laser light may be parallel to the emitted laser beam. In that case, the camera may be positioned as close as possible to the laser.

In an embodiment, multiple products are detectable at the same time, for instance when product carriers are positioned next to each other in a direction transverse to the conveyance direction. In that case, the detector may comprise multiple detection units which are preferably screened from each other to minimize interference.

In an embodiment of the conveyor system according to the invention, the rotation unit comprises a rotation element to rotate at least one product carrier about the deviation angle.

In an embodiment of the conveyor system according to the invention, the rotation element is an elongated rotation element which extends in the conveying direction.

In an embodiment, rotation of the product carriers by the rotation unit is carried out in a similar way using similar means as the above described rotation of the product carriers in the centring unit, with the exception that the amount of rotation of the product carriers is controllable for each product carrier in the rotating unit which is not necessary per se for the centring unit.

In a further embodiment of the conveyor system according to the invention, the rotation unit of the conveyor system may comprise an auxiliary detector. The auxiliary detector may be positioned downstream the conveying direction after the rotational element. The auxiliary detector may be used to control the desired orientation of the product. The auxiliary detector may be used to generate data relating to a secondary angular deviation. The data from the auxiliary detector may be used to calibrate an upstream rotation element to obtain a more accurate orientation. Herewith, the rotation element may be automatically controlled in a closed loop.

In a embodiment, the auxiliary detector may be used to control a gripping device which may be located downstream of the auxiliary detector to grip the products. For instance, the gripping device may comprise grippers which define a space in between the grippers, wherein the size of the space can be set by appropriate positioning the grippers relative to each other. The auxiliary detector may be used to determine a minimum size of the space in between the grippers, based on which the grippers are positioned in

accordance with the minimum size possibly including a tolerance to keep some initial distance between the respective grippers and the product. Further it is possible that the auxiliary detector allows to detect the size, position and/or orientation of a stem or stalk of a fruit and control the grippers of the gripping device such that contact with the stem or stalk is prevented to avoid damage to the grippers.

In an embodiment of the conveyor system according to the invention, the rotation element comprises a movable belt along an outer contour to get in engagement with an outer edge product carrier to rotate the product carrier during a time interval of engagement.

In an embodiment of the conveyor system according to the invention, the rotation element is movable from a first position, wherein the rotation element remains free from engagement with a conveyed product carrier to a second position, wherein the rotation element is in engagement with the conveyed product carrier.

In an embodiment of the conveyor system according to the invention, the product carrier may comprise an upper part and a lower part. The product carrier is rotatably connected to a base carrier. The upper part comprises the upper surface for carrying a product. The lower part of the product carrier comprises a disc for an engagement with a rotation element for rotating a carried product at the upper surface. In the conveyor system, the rotation element of the centring unit or rotation unit is engageable to the lower part of the product carrier which may provide several advantageous.

In comparison with a product carrier which is engaged at a circumference wall portion of the upper part, an engagement with the disc of the product carrier may be advantageous, because it allows a more compact arrangement of the product carriers in the transversal direction. The product carriers may be arranged close to each other without an intermediate positioned rotation element. The rotation element may be positioned below the upper part of the product carrier. Advantageously, more or larger product carriers may be arranged side by side in a transversal direction on a limited conveyor width.

In an embodiment of the conveyor system according to the invention, the upper and lower part may be both arranged above the base carrier, but preferably, the upper part is positioned at a first side above the base carrier and the lower part is positioned at a second opposite side under the base carrier. The product carrier may comprise a centre shaft which defines a centre axis of rotation of the product carrier during the centring stage or stage of rotation. The product carrier is connected rotatable to the base carrier by the shaft and the shaft connects the upper part to the lower part. The lower part of the product carrier is positioned at the underside of the base carrier. Herewith, the rotation element of the centring or rotation unit may engage with the disc of the lower part at the underside of the base carrier to rotate the upper surface of the product carrier above the base carrier.

Advantageously, the presence of the disc at the lower part allows a compact arrangement of the product carriers and the positioning at the underside of the base carrier allows a more clean configuration of the conveyor system.

In an embodiment, the conveyor system comprises an endless track having an upper horizontal section and a lower horizontal section, wherein the product carriers are mounted on the endless track, such that their upper surfaces mainly face upwards in the upper horizontal section and mainly face downwards in the lower horizontal section, and wherein the conveyor system comprises at each end of the endless track an element to respectively transfer the endless track from the upper horizontal section to the lower horizontal section or vice versa.

In an embodiment, the endless track may be formed by interconnected base carriers which in turn carry the product carriers. The base carriers may also be connected to a conveyor belt. Preferably, the base carriers are pivotably mounted to the conveyor belt about a horizontal pivot axis parallel to a direction transverse to the conveyance direction with their rear portion seen in conveyance direction, so that a front portion seen in conveyance direction is able to pivot upwards relative to the conveyor belt. This allows a base carrier to remain in a horizontal position for a longer period of time while the conveyor belt turns downward to the lower horizontal section at the end of the conveyor belt by pivoting relative to the conveyor belt, thereby allowing to longer facilitate operations at the end of the endless track, e.g. there is more time available for gripping of the products to transport the products to another conveyor system or device. Pivoting of the base carrier relative to the conveyor belt may be performed by an appropriate actuator which may be arranged between the base carrier and the conveyor belt. Alternatively, the base carrier may be guided at the front portion to remain in a horizontal orientation while the conveyor belt moves downwardly. The horizontal orientation of the base carrier is preferably maintained until the rear portion of the base carrier reaches the end of the endless tracks and also starts to move downwards along with the conveyor belt.

As described above, the product carrier may be moveable in at least two directions besides the conveyance direction, namely a vibration direction and a rotation direction in order to allow rotation of the product carrier during centring and in the rotation unit.

However, in the rotation unit, rotating the product carrier by the rotation element may then also cause the product carrier to move in the vibration direction which may be undesired as this movement may cause the product to move off-centre. The rotation unit thus preferably comprises guiding means to guide movement of the product carrier in the conveyance direction and rotational direction only, and thus to prevent movement of the product carrier in the vibration direction.

The invention also relates to a method for processing at least one product in a conveyor system, wherein at least one product is conveyed in a conveying direction, wherein the method comprises the steps of

- providing a product carrier, wherein the product carrier has an upper surface for carrying the product, and wherein the product carrier is rotatable about a rotation axis perpendicular to the upper surface;

- supplying the product to the upper surface of the product carrier;

- detecting an initial angular orientation of the product on the product carrier using a 3D detector;

- determining a deviation angle which is defined by a deviation of the initial angular orientation from a desired angular orientation;

- operating a rotation unit to rotate the product carrier about the rotation axis over the deviation angle.

In an embodiment, the product carried by the product carrier is a food article with a stem, such as fruit, paprika etc., wherein the 3D detector makes a 3D image of the product to determine the initial angular orientation from the detected location of the stem of the product.

In an embodiment, the product is a paprika, wherein the 3D detector makes a 3D image of the paprika to determine the initial angular orientation of the paprika from the detected lobes of the paprika.

The invention also relates to a conveyor system for processing products, wherein the conveyor system comprises;

- a product carrier, wherein the product carrier has an upper surface for carrying the product, and wherein the product carrier is rotatable about a rotation axis perpendicular to the upper surface; - a 3D detector for detecting an initial angular orientation of the product on the product carrier;

- a rotation unit for rotating the product carrier about the rotation axis.

In an embodiment, the 3D detector comprises a laser to emit a laser light beam towards the product and a camera to detect the of the product reflected laser light, wherein the 3D detector determines the distance to the product by triangulation.

In an embodiment, the laser emits a laser line having a width at least as large as the largest possible product that can be handled by the product carrier for simultaneously determining the distance to the product along the laser line.

Further preferred embodiments are defined in the sub-claims.

The invention will be explained in more detail with reference to the appended drawings. The drawings show a practical embodiment according to the invention, which may not be interpreted as limiting the scope of the invention. Specific features may also be considered apart from the shown embodiment and may be taken into account in a broader context as a delimiting feature of the invention, not only for the shown embodiment but as a common feature for all embodiments, in which: Fig. 1 A shows in a schematic view a first and a second stage I, II of a preferred method according to the invention for processing conveyed products;

Fig. 1 B shows in a schematic top view a conveyor system according to the invention; Figure 2A shows in a schematic front view a base carrier which supports at least three product carriers;

Figure 2B shows a top view of the base plate out of Fig. 2A with product carriers;

Figures 3A-3C show in a schematic top view subsequent steps for centring a loaded product on the product carriers;

Fig. 4A-4D show in a schematic top view a subsequent rotation of the product carriers to align loaded products and to obtain a desired orientation;

Fig. 4E shows an alternative embodiment of a rotation element 202 of a rotation unit

200 which comprises a moving outer surface; and

Fig. 5 shows an embodiment of a product carrier which allows a displacement of a product to a centre position of the product carrier;

Fig. 6 shows a side view of a product carrier supported by a base carrier for use in a conveyor system and method according to an embodiment of the invention:

Fig. 7 shows a top view of an agitator unit of a centring unit for use in a conveyor system and method according to an embodiment of the invention. Identical reference numbers are used in the drawings to indicate identical or similar components.

Fig. 1A shows in a schematic view a first and a second stage I, II of a preferred method according to the invention for processing conveyed products 1 in a conveyor system. In the method, products 1 are supplied which are loaded in a random orientation on product carriers 2. In the first stage I the products 1 .1 , 1 .2, 1 .3 are displaced to a centre position 21 of the product carriers 2. The products 1 .1 , 1 .2, 1 .3 are centred on the product carriers 2 at the centre position 21 . In the second stage II, the centred products 1 are rotated by rotating the product carriers 2 about the centre position 21 to a predetermined orientation. After passing the first and second stages I, II, the products are repositioned into a

predetermined orientation. After carrying out the preparing steps under stage I and stage II, the products can be processed further.

Fig. 1 B shows in a schematic top view an embodiment of a conveyor system 10 according to the invention. The shown portion of the conveyor system is in this embodiment an upper horizontal section of an endless conveyor system. The conveyor system 10 is arranged to convey products in a conveying direction 9. The conveyor system 10 has a supplier unit 300 for supplying products 1 to product carriers 2. The products are food articles like snacks or vegetables. The products are in this embodiment peppers of a paprika, which are known to have an amorphous shape. In the conveyor system, the products are conveyed along at least one operation unit 400 for carrying out an operation. The conveyor system in this embodiment is provided to operate at least two products together at the operation units. The conveyor system may be arranged for packaging products. The at least two products may be gripped together by a gripper unit to pack the products in one step in a package.

The supplier unit 300 has at least two, in particular three supplier devices 300.1 , 300.2, 300.3 for supplying the products to at least two, in particular three product carriers 2.1 , 2.2, 2.3. The product carriers 2 are arranged side by side on a base carrier 3. The conveyor system 10 is a multiple track conveyor system. The multiple track conveyor system comprises at least two, in particular three product tracks, travelling in an endless manner through the conveyor system. The product carriers are conveyed about the three product tracks in a conveying direction 9 by the base carrier 3 along the upper horizontal section. The base carriers 3 are coupled to each other in an endless manner, but may alternatively or additionally be mounted to a conveyor belt, in this case an endless conveyor belt. At the end of the endless conveyor system near operation unit 400, the base carriers are transferred to a corresponding lower horizontal section to be transported back to the beginning of the upper horizontal section near supplier unit 300. The product carriers have an outer dimension of at most 50cm, in particular at most 30cm. The product carriers have an outer dimension of at least 10cm, in particular at least 15cm.

The multiple track conveyor system may have an outer dimension of at most 3 metres, in particular at most 2 metres, wherein the outer dimension is defined as the dimension of the conveyor system in conveyance direction 9.

The supplier unit 300 supplies products from above to the product carriers 2. The products are in random orientation and at a random position supplied to an upper carrying surface of the product carrier 2. The supplied products can freely move over the upper surface of the product carrier. The products are positioned in a preparing step by a centring unit 100 and a rotation unit 200 before supplying the products to an operation unit 400. In the centring unit 100, the products are moved to a centre position of the product carrier. The centring unit 100 will be elucidated further with reference to Fig. 3A-3C. In the rotation unit 200, the products are oriented in a desired orientation. The rotation unit 200 will be elucidated by Fig. 4A-4D.

Fig. 1 B shows a first operation unit 400. The first operation unit 400 is a handling unit. The handling unit comprises a gripper for gripping at least two products from at least two product tracks in one gripping step. The products are gripped together. An advantage of the centring unit and the rotation unit is that the products are always supplied to the handling unit 400 in a predetermined orientation and position, so that the handling unit can easily and reliably handle the products. Further, in case the handling unit comprises grippers, the predetermined orientation and position may have the advantage that the grippers need less degrees of freedom thereby reducing the weight of the grippers and thus increasing the obtainable speed of the handling device. After being gripped, the distance between the products may be adjusted to prepare the products for packaging. Hence, the centring unit, rotation unit and the handling unit are able to package amorphous products such as peppers of a paprika, wherein each pepper usually has a different size and shape, in an efficient and fast way without damaging the peppers during handling/operation of the peppers.

Figure 2A shows in a schematic front view a base carrier 3 which supports at least two, in particular three product carriers. Figure 2B shows a top view of the base plate with product carriers 2.1 , 2.2, 2.3. A plurality of such substantially identical base carriers may be arranged in a conveyor system to convey at least two products. The base carriers 3 may be coupled to each other and/or positioned on a conveyor belt, e.g. an endless conveyor belt. The conveyor system may comprise at least one operating unit for treating or handling a product, in particular a food article. The base carrier 3 may be conveyed along several operating units to carry out an operating step. The base carrier 3 is plate shaped. The base carrier 3 comprises a tray to carry at least two product carriers 2. The base carrier 3 comprises at least two product carriers 2 which are disposed in a linear array. The product carrier 2 is arranged to carry a single product. The products 1 are loaded on an upper surface 22 of the product carrier. The upper surface is a top surface which is open from above to receive products. The product carriers 2 are arranged side by side on the base carrier 3 in a transversal direction. An arrow indicates a conveying direction 9 of the base carrier. The transversal direction is transversal, in particular perpendicular, to the conveying direction 9.

The base carrier 3 comprises an engagement element 4 to engage the base carrier 3 with an agitator unit of a centring unit 100. The agitator unit is a unit which generates a movement. By coupling a passing product carrier directly or indirectly via the base carrier 3 to the agitator unit, the generated movement is transferred to the product carrier. The generated and transferred movement will force a movement of the product to the centre position 21 . Here, the agitator unit is a vibration unit to vibrate the base carrier 3 during engagement of the base carrier 3 with the vibration unit.

The engagement element 4 is a pin which is connected to the tray. The pin extends upwardly from the base carrier. The pin is positioned close to an edge of the base carrier 3 to engage the pin with the agitator unit which is positioned adjacent the base carrier.

The vibration unit has a capture element 101 for capturing the engagement element 4 of the base carrier. The capture element 101 comprises an elongate profile. The elongate profile extends in the conveying direction 9. The elongate profile has an elongated slot at a bottom side. The slot is open at both heading faces of the profile to receive the engagement element 4 of the base carrier 3 during a conveying movement of the base carrier. The vibration unit generates vibrations having an amplitude directed in a transversal direction. The vibrations are directed in a horizontal plane. The vibration unit is arranged to vibrate the base carrier 3 in a direction transversal the conveying direction 9. During engagement of the base carrier 3 with the vibrator, transversal vibrations are transferred to the base carrier. The product carriers 2 will be vibrated by the base carrier 3 and a loaded product on the product carrier 2 will be vibrated such that the product displaces in transversal direction to a centre line which is parallel to the conveying direction 9.

The engagement between engagement element 4 and capture element 101 is preferably statically determinate and play-free to minimize disturbances and to prevent vibrations in other directions than the transversal direction. The statically determinate engagement can be obtained by providing an engagement element with a spherical outer shape for engagement with the capture element, this ensures that the engagement element and the capture element always contact each other at two contact points. The play-free engagement can be obtained by accurate manufacturing or by providing a spring-bias engagement, in which a spring always ensures contact between the engagement element and the capture element.

The product carrier 2 is rotatable connected to the base carrier 3. The product carrier 2 is rotatable about its centre axis. The product carrier 2 has an axis of symmetry which defines the centre axis. The vibration unit has a guide bar for rotating a passing product carrier 2. The guide bar is stationary positioned. The guide bar engages a passing product carrier 2 at an outer circumference to rotate the product carrier 2 about its centre axis. The guide bar may improve the centring efficiency of the centring unit. In case of vibrations in mainly a transversal direction, a rotation of the product carrier 2 brings a loaded product in such a position that the loaded product moves more easy to a centre position. The loaded product will move more easily to a centre position which is located at a front side when generated vibrations push the loaded product at a back side. In other words, the products are more susceptible for the single direction when the vibrations act on the product in a direction towards the centre position. By rotating the product carrier during a centring operation, the product and single direction of the vibrations will get substantially aligned for a certain time interval, during which time interval the product is maximally stimulated to move to the centre position.

The product carrier 2 is designed to carry a product. The shown product is a food article, in particular a vegetable, more in particular a fruit. The product has an amorphous outer contour. The amorphous product has a neutral position when positioned on the product carrier 2. In the neutral position, the loaded product is stationary positioned. The product is not clamped or connected to the product carrier 2, but the product is freely movable over the product carrier 2. Only a friction force maintains the product in the neutral position. The product carrier 2 has an upper surface 22 for receiving the product. A product can be loaded from above onto the product carrier 2.

The product carrier 2 has a centre position at the upper surface 22. For further operations to the conveyed products, it is desired to get a loaded product in a predetermined position, which is defined by the centre position 21 . It is desired to get the loaded product first in a stable neutral position. It is further desired to get the loaded product at the centre position 21 . The centre position may be a target area with borderlines. To obtain a desired centring of the product, it is desired to get the product within the borderline of the target area. For food articles, the borderline may have maximum dimensions which correspond to a maximum outer dimension of the food article including a tolerance of some centimetres. The target area may have a rectangular shape. For example, for a fruit like paprika the borderline of the target area may have an outer dimension of at most 25cm.

The product carrier 2 has an upper surface 22 with centring properties. The upper surface 22 comprises an inclined wall which is designed to force the product due to gravity forces to a lower region of the product carrier 2. The inclined wall is formed by a rounded, conical or tapered portion. The product carrier 2 further has an upstanding outer edge 23 to keep the product on the upper surface 22 of the product carrier 2. The outer edge 23 forms an obstacle to prevent the product from falling off the product carrier 2. The level of inclination is relatively small, in this case having a maximum of about 25 degrees with respect to the horizontal, in order to leave enough space for a gripper to grab the product without interfering with the inclined wall. The inclination may further be in the range of 0-10 or 0-15 degrees. The inclination may be a constant, e.g. 10 or 15 degrees or gradually change from one value to another value.

Figures 3A-3C show in a schematic top view subsequent steps for centring a loaded product on the product carriers 2. Fig. 4A-4D show in a schematic top view a subsequent rotation of the product carriers 2 to align loaded products to obtain a desired orientation.

In Figure 3A, the product carriers 2 are positioned at the base carrier 3 which is located upstream the conveying direction 9 before the vibration unit. The base carrier 3 has an engagement element 4 which is not yet agitated by the vibration unit. The arrow indicates the conveying direction 9. Conveyed products are oriented in two stages. In a first stage, the products are centred by a centring unit, in a second stage the centred products are subsequently aligned by rotation of the product carriers 2. A rotation unit 200 to align the products is arranged downstream the vibration unit.

In Fig. 3A, the centre unit 100 is a vibration unit which is shown in a top view which corresponds with the front view of Fig. 2A. As indicated above, the vibration unit comprises an elongate profile to engage with the base carrier 3 for transferring generated vibrations to the base carrier 3 and connected product carriers 2. The elongate profile has a through slot for capturing and passing the engagement element 4 of the base plate. Further, the vibration unit comprises three stationary positioned guide bars 102.1 ,102.2,102.3 to rotate the product carriers 2 during conveying. The presence of the guide bars improves the efficiency of the centring unit.

At the left, Fig. 3A further shows a graph of a sinusoidal vibration to illustrate a generated vibration having an amplitude in a transversal direction. The elongate profile 101 which generates the vibrations is connected at both ends to a framework of the vibration unit. Due to the fixation of the ends of the elongate profile, the vibrating elongate profile has a decreasing amplitude in a direction from the middle of the profile to the fixed ends. A middle region of the elongate profile will provide a stronger vibration. Herewith, the base carrier 3 is gradually vibrated when passing through the vibration unit, which amongst others reduces the amount of noise generated by the centring unit.

The rotation unit 200 is arranged downstream of the vibration unit. The working of the rotation unit 200 will be explained with reference to Fig. 4A-4D. In Fig. 3B, the vibration unit has just been engaged with the base carrier. The rotation unit 200 is not shown in Fig. 3B. The loaded products are randomly positioned at the upper surface 22 of the product carriers 2. The engagement element 4 of the base carrier 3 is received in the through slot of the elongate profile 101 of the vibration unit. Generated vibrations will be transferred to the base carrier 3 during engagement of the base carrier 3 with the vibration unit. The product carriers 2 are connected to the base carrier 3 and will also start vibrating. Due to the vibrations, the loaded products will displace to the lower situated centre position.

The product carriers 2 are each in engagement with a fixed guide bar 102 of the vibration unit. The product carrier has an outer circumference wall portion which is in contact with the guide bar 102. Due to the engagement with the guide bar, the product carrier 2 will start rotating about a centre axis. Due to the rotation, the loaded products 1 on the product carriers 2 will come in a position, wherein the products are more susceptible to generated vibrations in transversal direction. In this case, the product is at least during a certain time interval substantially aligned with the direction of the vibrations and the centre position, such that the vibrations act on the product in a direction towards the centre position.

Fig. 3C shows the base carrier 3 at a later moment when the product carriers 2 pass through the vibration unit. The products are displaced over the upper surface 22 of the product carrier 2 and are positioned at the centre position of the product carrier 2. In this centred position which represents a desired position, the products on the product carriers 2 will leave the vibration unit.

Fig. 4A-4D show a subsequent stage II after the centring stage I, wherein centred products on product carriers 2 are rotated to bring the products 2 in a desired angular orientation with respect to the base carrier. The base carrier 3 with centred products is supplied to a rotation unit 200. In the rotation unit 200, the product carriers 2 will be rotated to get the loaded products into the desired orientation, in particular to align the loaded products in a length direction of the products.

With reference to Fig. 4A, the rotation unit 200 comprises a detector 201 for observing an initial angular orientation of supplied products. The detector 201 is shown in Fig. 1 B and for simplicity reasons not in Fig. 4A. The product carrier is conveyed in a conveying direction along the detector to determine the initial orientation of the supplied products. The initial orientation may differ from the desired orientation. The desired orientation may for instance be determined by the stem of a fruit if present. An example of a desired orientation is that the stems should be positioned on the left or right side of the product as seen in conveyance direction 9. A control system, in particular a computer, is implemented to calculate a deviation angle which is defined by the difference between the desired and initial angular orientation. The deviation angle determines an angle of rotation which has to be performed by the rotation unit 200.

As shown in Fig. 4B, the rotation unit 200 comprises at least one rotation element 202 to rotate the at least one product carrier 2 about the deviation angle. The rotation unit 200 is provided with a rotation element for each product carrier 2 on the base carrier. Here, the rotation element is a movable positioned rotation element. The rotation element is elongated and extends in conveying direction 9. The rotation element is designed to get in engagement with the product carrier 2 to rotate the product carrier 2 about the

predetermined deviation angle. The rotation element 202 is movable in the transversal direction from a first position to a second position. The transversal direction is a direction transversal the conveying direction. In the first position, the rotation element 202 remains free from engagement with a passing product carrier 2. In the second position, the rotation element 202 is in engagement with the passing product carrier 2. The rotation element 202 is controllable to get in engagement with a passing product carrier 2 during a time interval. During the time interval, the product carrier 2 rotates and the product gets into the desired angular orientation. After the time interval, the rotation element is withdrawn into the first position, such that the product carrier 2 stops rotating.

Fig. 4C shows a particular moment during the operation of the rotation unit 200. The base carrier 3 is provided with three product carriers 2. At the illustrated moment, one of the three product carriers 2 is positioned in the desired orientation. At that moment, as indicated by the arrows, the rotation element 202.1 dedicated to the well oriented product carrier 2 is withdrawn to the first position. The other two rotation elements 202.2, 202.3 are still positioned in the second position and are still in engagement with the product carriers 2 to obtain a further rotation.

Fig. 4D shows a particular moment during the operation of the rotation unit 200, wherein all product carriers 2 are sufficient rotated to get the loaded products in the desired orientation. All rotation elements 202.1 , 202.2, 202.3 are positioned back into the first position to remain free of engagement with the product carriers 2. The product carriers 2 are further conveyed in the desired orientation. In the achieved desired orientation of the products, it may be easy to process the products further. It may e.g. be easy to pack the products on a single base carrier 3 by a single gripper to put the products together in one package.

In a further embodiment of the rotation unit 200, the conveyor system 10 may comprise an auxiliary detector 203. The auxiliary detector 203 is shown in Fig. 1 B. The auxiliary detector is positioned downstream the conveying direction after the rotational element 202. The auxiliary detector 203 is used to control the desired orientation of the product. The auxiliary detector 203 is used to generate data relating to a secondary angular deviation. The data from the auxiliary detector is used to fine tune an upstream rotation element 202 to obtain a more accurate orientation. Herewith, the rotation element may be automatically controlled in a closed loop.

In an embodiment, the auxiliary detector 203 may advantageously be used to determine whether the products are ready for handling by the operation unit 400 as shown in Fig. 1 B. For instance, if the desired orientation is a sideways extending stem from the product, but the stem is facing upwards, rotation of the product in the rotation unit will not move the product to the desired orientation. In fact, it may not be possible at all to get the product into the desired orientation. Hence, this can be detected by the auxiliary detector 203 and based on the output it may be decided to skip operation on the products by the operation unit and transport the products to a waste or storage location. Further, the auxiliary detector may be used to detect a malfunction in the detector 201 or the rotation unit 200. The auxiliary detector 203 may further be used to control the operation unit in relation to the detected position and orientation of the products. For instance, the sideways orientation of the stem on a product may be necessary in order to avoid contact between stem and grippers, which grippers may have bladders to grip the products without exerting too much pressure, and which can be damaged by the stems of the products. If in an embodiment, the grippers are rotatable about a vertical axis which allows to adapt the grippers to the orientation of the products, damage may be prevented by appropriate adjusting the orientation of the grippers to the orientation of the products. The auxiliary detector may further be used to adjust the distance between grippers of a gripping device to the size of the product to be gripped in order to ensure that the products can be gripped substantially simultaneously and/or the gripping force is kept below a predetermined value.

In Fig. 4A-4D an embodiment is illustrated of a rotation unit 200 including rotation elements 202 which has a stationary outer surface which is engageable to an outer circumference of a product carrier 2. A relative movement of a passing by product carrier is used to rotate the product carrier. The product carrier is rotated by the rotation unit during a conveying movement by using an occurring relative velocity between the rotation unit and the conveyed product carrier.

200 which comprises a moving outer surface. The shown rotation element 202 may also be integrated in the centring unit 100 to rotate a product carrier during a centring operation. The moving outer surface is positioned at the outer contour of the rotation element 202. A small arrow indicates the movement of the outer surface. The outer surface may be moved by moving the rotational element 102, 202 in the conveying direction 9.

In the shown embodiment, the rotation element 202 comprises a belt which extends along the outer circumference to provide the moving outer surface. The belt is tensioned by two pulleys which are provided at an end of the rotation element framework. The belt is drivable to move the outer surface. The outer surface can be brought in engagement with the product carrier 2 to rotate the product carrier 2. The product carrier 2 may be engaged during a conveying movement or during a standstill of the product carrier 2. The rotation element 202 with movable outer surface provides for both situations a possible rotation of the product carrier.

The speed of the movable outer surface may be varied to adapt the total amount of rotation of the product carrier during engagement. Fig. 4E shows three steps of rotation of a product. In a first step, the product carrier starts rotating. In the second step, the amount of rotation of the product satisfies a desired rotation. In the third step, the amount of rotation is not changed with respect to the second step by maintaining the speed of the outer surface of the rotation element equal to the speed of the conveyed product 1 .

Fig. 5 shows in a top view and in an above that view depicted cross sectional view an embodiment of a product carrier 2 which allows a displacement of a product to a centre position or so called target area of the product carrier 2. The product carrier 2 has an upper surface 22 which is initially flat shaped. The product carrier 2 has an at least partially upstanding edge to prevent products falling off the upper surface 22. The upper surface 22 is deformable. The upper surface 22 is made of a flexible material, in particular an elastomer material like rubber. The upper surface 22 may comprise an elastic material. An agitator unit which may also called an excitation unit is arranged to agitate the upper surface 22. In the shown embodiment, the upper surface 22 comprises an engagement element 4 which can be engaged by the agitator unit. The engagement element 4 is connected to the product carrier 2. The engagement element 4 is connected at an underside of the upper surface 22. The agitator unit may engage the upper surface 22 from underneath. The agitator unit may vibrate, press or pull the upper surface 22 downwards which will deform the upper surface 22. The upper surface 22 will obtain temporary an inclined wall portion which will force the product to the centre position of the product carrier 2.

Fig. 6 depicts a side view of a product carrier 2 supported by a base carrier 3 for use in a conveyor system according to an embodiment of the invention. The base carrier 3 may support multiple product carriers independently from each other at the same time, but for simplicity reasons only one product carrier is shown.

At the underside of the base carrier, i.e. the side of the base carrier facing away from an upper part of the product carrier, a support is arranged for the product carrier. Said support comprises two leaf springs 601 which extend between a base 603 and a support member 605 in conveyance direction 9. In fig. 6 only one leaf spring is shown, the other leaf spring is arranged parallel to the shown leaf spring and is therefore hidden behind the shown leaf spring. The parallel arrangement provides a linear guide for the support member, so that the support member is only able to move in a translational direction perpendicular to the plane of the drawing, i.e. perpendicular to the conveyance direction.

The support member 605 in turn rotatably supports the product carrier 2 about a rotation axis 607 which runs through a centre position 21 of an upper surface 22 of the product carrier, and which upper surface is configured to receive products in random orientation and random position. The product carrier 2 is mounted on an axle 609 extending from the product carrier through the base carrier to below the support member. The support member comprises a bearing, preferably a play-free bearing, to play-free guide the rotation of the axle 609. The support member further preferably comprises a damping element to damp rotation of the product carrier, which has the advantage that in absence of

engagement with a rotation element, the product carrier maintains its angular rotation, and that after engagement with a rotation element any residual rotational movement is stopped.

Rigidly connected to the axle is a disc 61 1 for engagement with respective rotation elements of a centring unit or a rotation unit, such as a guide bar or the rotation element of Fig. 4E. The disc 61 1 is provided at a lower part of the product carrier, which lower part extends below the base carrier, so that the rotation elements of the centring unit and the rotation unit can also be placed below the base carrier, which may be advantageous for a compact and safe conveyor system. Rotating the disc 61 1 will automatically rotate the upper surface 22 and thus move the product carried by the upper surface.

Below the disc 61 1 , an engagement element 4 is provided which is configured to engage with an agitator unit of the centring unit. This agitator unit is able to vibrate the engagement element 4 in a direction perpendicular to the plane of drawing, so that the entire product carrier will start to vibrate along with the agitator unit. The vibrations in combination with the concave shape of the upper surface 22 will move a product carried by the upper surface towards the centre position 21 . While vibrating, a rotation element may engage with the disc 61 1 to rotate the product carrier to aid in the centring operation of the centring unit.

As shown in Fig. 6, the engagement element has at least partially a spherical shape. This shape allows to statically determinate engage with the agitator unit, thereby preventing the product carrier from vibrating in another direction as well.

Fig. 7 shows a top view of an agitator unit for use in a conveyor system or method according to an embodiment of the invention. The agitator unit comprises three portions. A middle portion 701 and two outer portions 703 mounted to a respective end of the middle portion 701 . The middle portion 701 is moveably supported in a direction perpendicular to a conveyance direction 9 and can be actuated by an appropriate actuator (not shown), e.g. an electromagnetic, pneumatic or hydraulic actuator to vibrate in said direction. The frequency of said vibrations may be in the order of 500 - 1500 Hz, more particularly in the order of 800 - 1000 Hz. The outer portions are with one end connected to the middle portion and with another end to a framework 705. To illustrate the moveability of the agitator unit, the middle and outer portions are shown in one extreme position by solid lines and in another extreme position by dashed lines. Not shown is that the middle and outer portions of the agitator unit can also take any position in between the extreme positions. While vibrating, the amplitude may be less than the maximum amplitude corresponding to the extreme positions, as for instance each product carried by a product carrier may have its own optimum amplitude and frequency in order to centre the product on an upper surface of the product carrier.

The framework and the middle and outer portions of the agitator unit each comprise two parallel guide members 707 and 708 to define a path for an engagement element of a product carrier to follow when the engagement element is received in between the guide members and the product carrier moves in the conveyance direction . The guide members 707 and 708 of the outer portions 703 are hingably mounted to the respective guide members of the middle portion and the framework to allow movement of the middle portion in the transverse direction perpendicular to the conveyance direction without having to deform the agitator unit as in the case of a single profile as shown in relation to figs. 3A-3C and figs. 4A-4D.

When a product carrier passes the agitator unit, the engagement element, for instance the engagement element 4 of fig. 6 will be received in between the guide members 707,708 of the framework 705 on the left of Fig. 7. As the product carrier is moved in the conveyance direction, the engagement element will enter the left outer portion and will start to vibrate. Upon arrival at the middle portion, the amplitude of the vibration has reached a maximum until the right outer portion is entered. While running in between the guide members of the right outer portion, the amplitude of the vibration reduces to zero and subsequently the right framework will guide the engagement element thereby damping any residual vibration in the product carrier.

In the embodiment of fig. 7, the framework only guides the engagement element for a predetermined distance. However, this principle may also be applied at other positions of the product carrier within the conveyor system, for instance when the product carrier passes a rotation unit, in which rotation unit it is undesired for the product carrier to vibrate. Similar framework sections with guide members as the framework section 705 may then be applied there as well in order to suppress any motion in the transverse direction and only allowing a rotation of the product carrier.

Preferably, the engagement of the engagement element between the guide members is a play-free engagement, which may be provided by using resilient guide members having a relatively high stiffness to apply contact at any time during vibration of the product carrier. Fig. 8 depicts a practical embodiment of a detector 201 or 203 already described in relation to Fig. 1 B. Shown are a product carrier 2 carrying a product 1 . The product carrier including product are positioned in detector 201 , 203, which detector comprises a laser source 801 and a camera 803. The laser source emits a laser beam 805 towards the product carrier 2 and product 1 . The detector is configured to obtain 3D data, in particular the height profile of the product 1 . The laser beam 805 is thus preferably oriented parallel to the vertical to reduce the chance of obstructions of the laser beam as much as possible. The laser beam is further emitted in the form of a laser line covering the entire width of the product carrier, so that independent of the position of the product on the product carrier, the laser line is incident to the passing product.

The laser beam 805 is reflected of the outer surface of the product, wherein the reflected beams usually diverge in all kind of directions.

The camera 803 is arranged as close to the laser source as possible. The camera comprises a detection unit 807, e.g. a CCD camera, and optical components 809 to image the reflected laser beams on the detection unit 807. The optical components define a collection cone bounded by dashed lines 81 1 , which collection cone defines what the camera is able to see/detect. The collection cone comprises a central optical axis 813, which optical axis 813 is arranged parallel to the emitted laser beam 805 due to the close arrangement of the camera next to the laser source.

The detector is able to gather 3D information about the product, because the height at which the laser beam reflects of the product determines where the image of the laser line is formed on the detection unit, so that from the position of the formed image, information can be obtained about the height. This is called laser beam triangulation.

Fig. 9 shows the passage of a product carrier 2 carrying a product 1 with a stem 901 through a detector 201 ,203 of Fig. 8 having a laser line 903 in four steps, in the first step, the product carrier is about to enter the detector. In the second step, the product carrier has entered the detector such that the laser line is about to scan the product. In step 3, the product has been fully scanned, and in step 4, the product carrier has left the detector. From the obtained data, the control unit of the detector is able to determine the position of the stem 901 and thus what the angular orientation is of the product 1.

Although the invention has been disclosed with reference to particular embodiments, from reading this description those of skilled in the art may appreciate changes and modification that may be possible from a technical point of view but which do not depart from the scope of the invention as described above and claimed hereafter. It will be understood by those of skilled in the art that equivalents may be substituted for elements thereof without departing from the scope of the invention. Modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1 . Method for processing at least one product in a conveyor system, wherein at least one product (1 ) is conveyed in a conveying direction (9), wherein the method comprises the steps of:

• providing a product carrier (2), wherein the product carrier (2) has an upper surface (22) for carrying the product (1 ), wherein the carried product (1 ) is freely movable over the upper surface (22) and wherein the upper surface (22) has a centre position (21 );

• supplying the product to the upper surface (22) of the product carrier (2);

• providing a centring unit (100) for positioning a product (1 ) on the product carrier (2) at the centre position (21 ); and

• operating the centring unit (10) to displace the product (1 ) to the centre position (21 ) of the product carrier (2).

2. Method according to claim 1 , wherein the provided centring unit (100) comprises a vibration unit and wherein the product carrier is vibrated by the vibration unit to force the carried product to the centre position (21 ).

3. Method according to claim 1 or 2, wherein the product carrier is vibrated and rotated about a vertical axis to force the carried product to the centre position (21 ), which vertical axis is positioned at the centre position (21 ).

4. Method according to any of the preceding claims, wherein the vibration unit generates during a first time interval vibrations with a large amplitude and during a second time interval vibrations with a small amplitude.

5. Method according to any of the preceding claims, wherein the conveyor system is of a continuous type, wherein products are conveyed continuously at a substantially constant velocity.

6. Method according to any of the preceding claims, wherein the product carrier is vibrated by a vibrating elongated profile (101 ) which generates vibrations in a transversal direction.

7. Method according to any of the preceding claims, wherein the method further comprises a step of: • providing a rotation unit (200) for rotating the product carrier;

• determining an initial angular orientation of the product on the product carrier;

• determining a deviation angle which is defined by a deviation of the initial angular orientation from a desired angular orientation;

5 · operating the rotation unit (200) to rotate the product carrier (2) about the deviation angle.

8. Method according to any of the preceding claims, wherein the product carrier (2) is rotated by the rotation unit during a conveying movement by using an occurring relative

10 velocity between the rotation unit (200) and the conveyed product carrier (2).

9. Method according to any of the preceding claims, wherein the method comprises the step of providing a base carrier (3) which carries at least two product carriers (2) which are arranged in an array, wherein the product carriers (2) are rotatable connected to the base

15 carrier (3), wherein the base carrier (3) is conveyed together with the product carriers (2) for processing multiple products (1 ) as a group, e.g. to grip the multiple products together with a single gripper.

10. Method according to any of the preceding claims, wherein the at least two product 20 carriers (2) are arranged side by side in a direction transversal the conveying direction (9).

1 1 . Method according to any of the preceding claims, wherein the method comprises the step of aligning side by side arranged products (1 ).

25 12. Conveyor system (10), in particular a multiple track conveyor system, for processing products (1 ), wherein the conveyor system comprises:

• a product carrier (2), wherein the product carrier has an upper surface (22) for

carrying the product (1 ), wherein the carried product (1 ) is freely movable over the upper surface (22) and wherein the upper surface (22) has a centre position (21 );

30 and

• a centring unit (100) for centring the carried product (1 ) on the product carrier (2) such that the product is positioned at the centre position (21 ).

13. Conveyor system according to claim 12, wherein the upper surface (22) of the 35 product carrier comprises at least one inclined wall portion and wherein the centre position (21 ) is positioned at a lower region of the upper surface.

14. Conveyor system according to claim 12 or 13, wherein the upper surface (22) of the product carrier is at least partially deformable (Fig. 5) to obtain a temporary inclined wall portion when the upper surface (22) is agitated for forcing the product to the centre position (21 ).

5

15. Conveyor system according to any of the claims 12-14, wherein the product carrier (2) has at least partially an upstanding outer edge (23) for preventing a product from falling off the product carrier.

10 16. Conveyor system according to any of the claims 12-15, wherein at least the upper surface (22) of the product carrier (2) is rotatable with respect to the conveying direction (9) about a centre axis of the product carrier (2), wherein the centre axis passes through the centre position (21 ).

15 17. Conveyor system according to any of the claims 12-16, wherein the centring unit (100) comprises a vibration unit for vibrating a product carrier.

18. Conveyor system according to claim 17, wherein the vibration unit is arranged to generate vibrations in a direction transversal the direction of conveyance (9).

20

19. Conveyor system according to any of the claims 12-18, wherein the centre unit comprises a capture element (101 ) to engage with the product carrier (2) to vibrate the product carrier.

25 20. Conveyor system according to any of the claims 12-19, wherein the capture element is an elongated profile (101 ), wherein the elongated profile is fixedly connected at both ends to a framework.

21 . Conveyor system according to any of the claims 12-20, wherein the centring unit

30 (100) comprises at least one rotation element (102, 202) for engaging and rotating a product carrier during a centring operation.

22. Conveyor system according to claim 21 , wherein the rotating element is a guide bar, which guide bar (102) is stationary disposed, such that an engaging product carrier (2)

35 rotates when passing by.

23. Conveyor system according to any of the claims 12-21 , wherein the centring unit (100) comprises push means to push a product on a product carrier towards the centre position.

24. Conveyor system according to any of the claims 12-22, wherein the conveyor system 5 comprises a base carrier (3) for carrying multiple products which base carrier (3) carries at least two product carriers for processing multiple products as a group, wherein the product carriers are rotatable connected to the base carrier (3).

25. Conveyor system according to claim 24, wherein the at least two product carriers are 10 disposed in a linear array on top of the base carrier.

26. Conveyor system according to claim 24 or 25, wherein the base carrier or product carrier comprises an engagement element (4) to obtain an engagement with the centring unit.

15

27. Conveyor system according to any of the claims 12-26, wherein the conveyor system further comprises a rotation unit (200) for rotating a product carrier (2), which rotation unit (200) is disposed downstream the conveying direction after the centring unit (100).

20 28. Conveyor system according to claim 27, wherein the rotation unit (200) comprises a detector (201 ) for detecting an initial orientation including an initial angle of the product carried by the product carrier (2).

29. Conveyor system according to claim 27 or 28, wherein the rotation unit (200)

25 comprises a control unit to determine a deviation angle defined by the difference between the initial angle and a desired angle of a desired orientation.

30. Conveyor system according to any of the claims 27-29, wherein the rotation unit (200) comprises a rotation element (202) to rotate at least one product carrier about the

30 deviation angle.

31 . Conveyor system according to any of the claims 27-30, wherein the rotation unit of the conveyor system comprises an auxiliary detector (203) which is positioned downstream the conveying direction (9) after the rotational element (202) of the rotation unit to calibrate

35 an upstream positioned rotation element (202).

32. Conveyor system according to claim 30 or 31 , wherein the rotation element (202) is an elongated rotation element which extends in the conveying direction (9), which elongated rotation element has a stationary outer surface which is engageable with a passing product carrier to rotate the product carrier.

33. Conveyor system according to claim 30 or 31 , wherein the rotation element comprises a movable belt which forms a movable outer surface along an outer contour to get in engagement with an outer edge of a product carrier (2) to rotate the product carrier during a time interval of engagement.

34. Conveyor system according to any of the claims 30-33, wherein the rotation element (202) is movable from a first position, wherein the rotation element (202) remains free from engagement with a conveyed product carrier to a second position, wherein the rotation element (202) is in engagement with the conveyed product carrier (2).