EP0644120A1

EP0644120A1 - Apparatus and method for packing substantially spherical articles in boxes or cases

Info

Publication number: EP0644120A1
Application number: EP94202689A
Authority: EP
Inventors: Adrianus Wilhelmus Tas
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-09-20
Filing date: 1994-09-19
Publication date: 1995-03-22
Also published as: NL9301625A

Abstract

A method and apparatus for filling boxes or cases with layers stacked on top of each other and formed from substantially spherical articles arranged in a desired pattern. The apparatus comprises feed means, pattern forming means (2) for forming an article layer arranged in a desired pattern, pick-up means (4) for picking up the article layer as a whole and placing it in a box or case (5), the pattern forming means comprising a plurality of parallel paths (2a-2e), each path, adjacent to the in-feed side of the pattern forming means, comprising a conveyor track (6a-6e) whose discharge side connects to a series of rotatable, hourglass-shaped rollers (7), arranged behind each other and spaced apart at a pitch distance such that between two successive rollers a nest is present capable of receiving one article, the conveyor tracks and the hourglass-shaped rollers of each path being drivable independently of the conveyor tracks and rollers located in the other paths.

Description

The invention relates to an apparatus for filling boxes or cases with layers stacked on top of each other and formed from substantially spherical articles, such as for instance fruits, arranged in a desired pattern, the apparatus comprising feed means, an outlet of which connects to an inlet of pattern forming means for forming an article layer arranged in a desired pattern in a pick-up area, and pick-up means, movable in a horizontal and vertical plane, for picking up the article layer as a whole from the pick-up area and placing it in a box, for instance made of cardboard, or case.
Such an apparatus is known for packing oranges from Dutch patent application 8103567. In the known apparatus, the pattern forming means are formed by a plurality of parallel chutes in an inclined plane, with a retaining element arranged in each chute. The articles are guided into the chutes and roll down in the inclined chute and run into the retaining element. A drawback of the known apparatus is that it only functions properly if the articles to be packed are substantially spherical and approximately of the same size. Another drawback of the known apparatus is that the articles may get damaged when they run into the retaining elements. In the case of oranges, which have rather a thick peel, this damage will not quickly occur. In the case of other fruits, such as for instance tomatoes, aubergines, apples and the like, the peel is much more vulnerable, so that the processing of these fruits by means of the known apparatus would inevitably lead to damage. A further drawback of the known apparatus is that it cannot exert any influence over the orientation of the fruits before they are picked up to be placed in the box or case.
The object of the invention is to provide an apparatus without the above-mentioned drawbacks.
To that end, the apparatus is characterized in that the pattern forming means comprise a plurality of parallel paths, each path having, adjacent to the in-feed side of the pattern forming means, a conveyor track whose discharge side connects to a series of rotatable, hourglass-shaped rollers, arranged behind each other and spaced apart at a pitch distance such that between two successive rollers a nest is present capable of receiving one article, the conveyor tracks and the hourglass-shaped rollers of each path being drivable independently of the conveyor tracks and rollers located in the other paths.
The operation of the thus constructed apparatus is as follows. The articles are supplied in an unorderly manner on the feed means, which may for instance be designed as a conveyor belt, an inclined slide plate or the like. At the discharge end of the feed means, the articles are transferred to the conveyor tracks, driven independently of each other and forming the in-feed side of the pattern forming means. The conveyor track of a path conveys the article in the direction of the hourglass-shaped rollers of that path and the article is received in the first nest, located closest to the discharge side of the conveyor track and formed between two hourglass-shaped rollers. The article remains rotating in the nest until the conveyor track associated with the relevant path feeds a second article. When the second article touches the first article, the rotation of the first article is braked or stopped and the first article is moved into the following, second nest through the thrust of the second article and the rotation of the foremost hourglass-shaped roller which bounds the first nest. The second article itself is received in the first nest. When a path already contains several articles, this displacement phenomenon successively occurs for all articles located in the path. This process is repeated until all nests of the relevant path of the pattern forming means have been filled, which may for instance be observed by an electric eye arranged at the final nest, remotest from the conveyor track. After all nests of the path have been filled, the drive of the conveyor track and of the hourglass-shaped rollers of that path is stopped. Such filling process takes place simultaneously in all paths of the pattern forming means. When all paths of the pattern forming means have been filled, at least a plurality of the articles can be picked up from the pattern forming means by the pick-up means and placed in a box or case. Such a method to which the invention also relates is described in claim 12. Optionally, as described in claim 14, the hourglass-shaped rollers may be driven in the opposite direction for a while before the pick-up means pick up the articles from the pattern forming means. It can thus be provided that the articles come to lie in the nests in an optimum and central position and, moreover, the possibility of two articles being located in one nest is ruled out. After the articles have been picked up by the pick-up means, it is observed that not all nests of the pattern forming means are filled anymore and the drive of the conveyor tracks and the hourglass-shaped rollers is started again, so that the filling process is repeated.
With the apparatus according to the invention, the artices are arranged in a pattern without colliding in an uncontrolled manner. This enables relatively vulnerable articles such as, for instance, tomatoes, to be processed without damage. Moreover, the apparatus does not require that the articles are practically spherical, but articles having a shape other than spherical, such as for instance paprikas, aubergines or the like, may be processed as well.
In accordance with a further elaboration of the invention, the apparatus is characterized in that the hourglass-shaped rollers of two adjoining paths are staggered in longitudinal direction relative to each other, so that a center line of an hourglass-shaped roller in one path is in line with the center of a nest in the adjoining path. Pattern forming means of such design permit the formation of a layer having a greatest possible degree of filling, because the articles therein are disposed in a zigzag pattern.
In a further elaboration in accordance with the invention, the pick-up means comprise at least a pick-up head capable of moving upward and downward and attached to a travelling trolley arranged for movement in a horizontal direction, which pick-up head comprises a plurality of suction cups arranged in a pattern corresponding to the pattern of the nests in the pick-up area of the pattern forming means.
For pick-up means comprising such a pick-up head, a suction cup is present for each article arranged in the pattern forming means. Hence, the articles are each picked up separately, which offers the advantage that the articles can be transferred from the pattern forming means to the case or box in a very controlled manner and without damage.
In this connection, it is particularly favorable if the suction cups are arranged for movement from and toward each other at least in a direction perpendicular to the path direction of the pattern forming means. With a pick-up head of such design it is possible to move the articles, which are still spaced apart at some distance on the pattern forming means, against one another, so that an optimum filling of the box or case can be realized.
In order to optimize the filling of the box even further, it is particularly favorable if the pick-up head is rotatable around a vertical axis through at least 180°. It is thus provided that the layers in the box or case are alternately staggered relative to each other, as a result of which the articles of a superjacent layer is placed in the nests between the articles of the subjacent layer, yielding the densest possible stacking.
In order to minimize the damage to the articles in the box or case, it is particularly favorable if the travelling trolley comprises a carrying plate gripper capable of moving upward and downward and mounted on the travelling trolley at a distance from the pick-up head such that it is located above the box or case if the pick-up head is located above the pick-up area of the pattern forming means. At the same time when a layer of articles is placed in the box or case, the carrying plate gripper picks up a carrying plate from the carrying plate storage bin. Subsequently, the pick-up head is moved above the pattern forming means again for picking up a next layer of articles. The carrying plate gripper will then be located above the box or case and the carrying plate can be placed in the box or case. Generally, such a carrying plate is of a slightly curved design and provided with receiving curves or nests for receiving articles. The carrying plates provide that the articles are accommodated in the case or box in a stable manner, while the chance of damage to the articles is minimized.
In practice, it appears that if the articles are fruits, customers are more stimulated to buy the fruits if these fruits are all arranged in the same orientation. In the case of apples, this means that they should all be positioned with their bloom facing upward and the stalks pointing to one direction.
To realize this, according to a further elaboration of the invention, the apparatus is characterized in that the hourglass-shaped rollers bounding the nests that form the pick-up area can be driven independently of the hourglass-shaped rollers disposed upstream, an article carrier being provided under each nest of at least the pick-up area, which article carriers are movable upward and downward independently of each other, the apparatus comprising a vision device designed to determine the orientation of each article in the pick-up area and the article carriers being controllable for lifting the article from the relevant nest, depending on the orientation of the article observed by the vision device.
When all nests in the pick-up area of the pattern forming means have been filled, the drives of the conveyor tracks and of the hourglass-shaped rollers which do not bound the nests of the pick-up area are stopped, thereby thus discontinuing the supply of further articles in the direction of the pick-up area. The drives of the hourglass-shaped rollers bounding the nests of the pick-up area remain switched on. Consequently, the articles located in the pick-up area mainly rotate around a horizontally oriented principal axis thereof. The vision device observes for instance the color of each separate article. If, for instance, the apparatus processes apples and has been programmed for placing the apples in the box or case with their red sides facing upward, the control will provide a signal for moving the article carrier upward at the moment when the vision device observes that the apple, rotating in the nest under which the relevant carrier is located, has its red side facing upward.
Thus, it can be provided that for instance apples are placed in the box or case with their red bloom all facing upward.
In accordance with a further elaboration of the invention, it is particularly favorable if article carriers, movable upward and downward, are also located under the row of nests located directly upstream of the pick-up area. These additional article carriers prevent frictional forces from being exerted on the articles located in the relevant row of nests during the orientation process, as the articles are on the one hand supported by a rotating hourglass-shaped roller and on the other by a stationary hourglass-shaped roller.
In accordance with a further elaboration of the invention, at least each article carrier located under the pick-up area is rotatable around the vertical center line thereof.
In accordance with an alternative further elaboration of the invention, the pick-up head comprises a suction cup for each article located in the pick-up area, the suction cup being rotatable around a vertical center line.
With article carriers or pick-up head suction cups of such design, it is also possible to orient the article around a vertically directed principal axis thereof. In the case of apples, it can for instance be observed by means of the vision device where the stalks of the apples are located. Depending on the view observed by the vision device, the article carrier can be rotated around the vertical center line until the center line through the stalk and the crown of the apple points toward a particular, desired direction. When the apples are all oriented in the same direction, the apples can be placed in the box or case by means of the pick-up head.
In accordance with a further elaboration of the invention, it is particularly favorable if the travelling trolley carries the vision device, the vision device being mounted at such a distance from the pick-up head that the vision device is located above the pick-up area when the pick-up head is located above the box or case. Hence, with an apparatus of such design it is possible to move the carrying plate gripper above the box or case and the carrying plate storage bin, the pick-up head above the box or case and the pick-up area, and the vision device above the pick-up area by means of one horizontal displacement mechanism. As such a construction requires a minimum of parts, it can be manufactured in an economical manner.
To explain the invention, two exemplary embodiments of the apparatus will be described with reference to the accompanying drawings. In these drawings:

Fig. 1 is a side elevation of a first exemplary embodiment;
Fig. 2 is a detail of the side elevation of Fig. 1 in a different processing state;
Fig. 3 is a sectional view taken on line III-III of Fig. 1;
Fig. 4 is a sectional view taken on line IV-IV of Fig. 1;
Fig. 5 is a sectional view taken on line V-V of Fig. 4;
Fig. 6 is a side elevation of another exemplary embodiment of the apparatus, wherein the pick-up head is located above the pick-up area;
Fig. 7 is a side elevation as shown in Fig. 6, wherein the pick-up head is located above the box or case and the vision device is located above the pick-up area;
Fig. 8 is a detail of the pick-up area of the pattern forming means of the apparatus of Fig. 6; and
Fig. 9 is a top plan view of the detail shown in Fig. 8.

Fig. 1 shows an exemplary embodiment of the apparatus in side elevation. The exemplary embodiment shown comprises feed means, constructed in the form of a slide plate 1, pattern forming means 2 for forming an article layer arranged in a desired pattern in a pick-up area 3, and pick-up means 4 for placing the article layer in a box or case 5. The pattern forming means shown in top plan view in Fig. 3 comprise a number of parallel paths 2a-2e. Each path 2a-2e comprises, adjacent to the in-feed side thereof, a conveyor track constructed as a conveyor belt 6a-6e. The discharge side of the conveyor track connects to a series of rotatable, hourglass-shaped rollers 7, arranged behind each other and spaced apart at a pitch distance such that between two successive rollers 7 a nest 8 is present capable of receiving one article. The conveyor tracks 6a-6e and the hourglass-shaped rollers 7 of each path 2a-2e can be driven independently of the conveyor tracks 6a-6e and rollers 7 located in the other paths 2a-2e. In the exemplary embodiment shown, the rollers of each path are driven by a drive belt 9a-9e engaging the bottom side of the rollers. The drive belts 9a-9e are each connected, via a coupling 10a-10e, to a single drive shaft 11, driven, for instance, by an electric motor (not shown). Via the same couplings 10a-10e and a drive belt 12a-12e, the drive shaft 11, driven by the electric motor, also drives the conveyor tracks 6a-6e.
Fig. 1 shows the situation that an article on the conveyor track 6 just touches the article lying in the first nest 8, located closest to the conveyor track 6. As a result, all articles located in the nests 8 of that path 2 shift one position further in the manner wherein each falling domino in a row of dominoes arranged behind each other causes the fall of a next domino. Fig. 2 shows the situation that the articles V rotate around their own axes in the nest 8 wherein they are located. To enable observation whether the pattern forming means 2 are completely filled with articles, an electronic eye 36 is arranged at the last nest of each path 2a-2e of the pattern forming means.
As is clearly shown in Fig. 3, the hourglass-shaped rollers 7 of two adjoining paths 2, 2' are staggered, so that a center line of an hourglass-shaped roller 7 in one path 2 is in line with the center of a nest in the adjoining path 2'.
The pick-up means 4 comprise a pick-up head 13, capable of moving upward and downward by means of a piston 14 and attached to a travelling trolley 15, displacable in horizontal direction. The pick-up head comprises a number of suction cups 16, which number of suction cups 16 corresponds to the number of nests 8 in the pick-up area 3 of the pattern forming means 2. By means of the piston/cylinder assemblies 20, the suction cups 16, located perpendicularly above the paths 2a-2e, can be moved from and toward each other in a direction perpendicular to the direction of the paths 2a-2e, as a result of which the layer of articles that is formed in the box or case 5 has indeed the maximum degree of filling. Moreover, the pick-up head 13 is rotatable around the piston rod 17 of the piston/cylinder assembly 14 by means of the rotatably drivable catch cam 18 connected to the catch 19. As a result, the layers can also be mutually accommodated in the case or box 5 with the densest stacking possible, because the articles of a superjacent layer are placed in the nests between the articles of the subjacent layer.
In the exemplary embodiment shown, the travelling trolley 15 further comprises a carrying plate gripper 22, capable of being moved upward and downward by means of a piston/cylinder assembly 21 and designed to pick up carrying plates 24 from a carrying plate storage bin 23 and place these carrying plates 24 on the layers of articles accommodated in the case or box 5. In general, the carrying plates are provided with curves adjusted to the uneven surface of a layer of articles. Hence, the carrying plate gripper 22 is also rotatable, by means of a catch cam 25 and a catch 26, through at least 180° around the piston rod 27 of the piston/cylinder assembly 21.
Figs 6-9 relate to another exemplary embodiment of the apparatus wherein the parts that correspond to parts of the exemplary embodiment shown in Figs 1-5 have been designated by the same reference numerals. The exemplary embodiment shown in Figs 6-9 comprises additional means for placing articles in the box or case 5 in a specific, desired orientation. Especially when the articles are fruits, this is of particular importance, as a uniform orientation of the fruits in the box or case stirs up the customers' buying interest.
For this purpose, the apparatus shown comprises a separate driving mechanism for the hourglass-shaped rollers 7 which bound the pick-up area 3. Here, too, the drive in each path is effected by a belt 28, per path engaging the bottom side of the hourglass-shaped rollers 7, which belts 28 are each driven, via a coupling 29, by a shaft 30 that is of a single construction and driven via a chain by a motor 31. Moreover, provided under each nest 8 of the pick-up area 3 is an article carrier 32, capable of moving upward and downward. Under the row of nests 8 directly upstream of the pick-up area 3, there are also provided article carriers 32, capable of moving upward and downward. The travelling trolley 15 carries, next to the pick-up head 13 and the carrying plate gripper 22, a vision device 33 composed of a number of cameras 34, providing a camera 34 for each nest 8 in the pick-up area 3. When the pick-up head 13 is located above the box or case 5, the cameras 34 of the vision device 33 are above the pick-up area 3 of the pattern forming means 2. The drive mechanism 31 of the hourglass-shaped rollers 7 bounding the nests 8 of the pick-up area 3 remains switched on when the pattern forming means 2 have already been filled completely. The vision device 33 located above the pick-up area 3 observes the orientation of each article within the pick-up area 3 and, depending on the observed orientation of an article, provides via a control (not shown) a signal for moving upward to the article carriers 32. This involves the article being lifted from the nest 8 in the desired orientation. For the purpose of orienting the articles around a vertical axis, the article carriers 32 themselves are rotatable around a vertical axis. In an alternative embodiment, the suction cups 16 of the pick-up head 13 may be rotatable around a vertical axis, instead of the article carriers 32. Fig. 6 shows the situation wherein the pick-up head 13 is located above the pick-up area 3, while Fig. 7 shows the situation that the pick-up head 13 is located above the box or case 5 and the vision device is located above the pick-up area 3 for observing the orientation of the articles V. Figs 8 and 9 respectively show a side and top plan view of the article carriers 32 in detail. The article carriers 32 can be moved upward and downward in vertical direction by means of piston/cylinder assemblies 35. It is clear that Figs 8 and 9 show two possible embodiments of the article carriers 32 and the hourglass-shaped rollers 7.
It is readily understood that the invention is not limited to the above-described exemplary embodiment, but that various modifications are possible within the scope of the invention.

Claims

An apparatus for filling boxes or cases with layers stacked on top of each other and formed from substantially spherical articles, such as for instance fruits, arranged in a desired pattern, the apparatus comprising feed means, an outlet of which connects to an inlet of pattern forming means for forming an article layer arranged in a desired pattern in a pick-up area, and pick-up means, movable in a horizontal and vertical plane, for picking up the article layer as a whole from the pick-up area and placing it in a box or case, characterized in that the pattern forming means (2) comprise a plurality of parallel paths (2a-2e), each path having, adjacent to the in-feed side of the pattern forming means, a conveyor track (6a-6e) whose discharge side connects to a series of rotatable, hourglass-shaped rollers (7), arranged behind each other and spaced apart at a pitch distance such that between two successive rollers (7) a nest (8) is present capable of receiving one article (V), the conveyor tracks (6a-6e) and the hourglass-shaped rollers (7) of each path (2a-2e) being drivable independently of the conveyor tracks (6a-6e) and rollers (7) located in the other paths (2a-2e).
An apparatus according to claim 1, characterized in that the hourglass-shaped rollers (7) of two adjoining paths (2a-2e) are staggered in longitudinal direction relative to each other, so that a center line of an hourglass-shaped roller (7) in one path (2a-2e) is in line with the center of a nest (8) in the adjoining path (2a-2e).
An apparatus according to claim 1 or 2, characterized in that the pick-up means (4) comprise at least a pick-up head (13) capable of moving upward and downward and attached to a travelling trolley (15) arranged for movement in a horizontal direction, said pick-up head (13) comprising a plurality of suction cups (16) arranged in a pattern corresponding to the pattern of the nests (8) in the pick-up area (3) of the pattern forming means (2).
An apparatus according to claim 3, characterized in that the suction cups (16) are arranged for movement from and toward each other at least in a direction perpendicular to the path direction (2a-2e) of the pattern forming means (2).
An apparatus according to claim 3 or 4, characterized in that the pick-up head (13) is rotatable around a vertical axis through at least 180°.
An apparatus according to claim 3, characterized in that the travelling trolley (15) comprises a carrying plate gripper (22) capable of moving upward and downward and mounted on the travelling trolley (15) at a distance from the pick-up head (13) such that it is located above the box or case (5) if the pick-up head (13) is located above the pick-up area (3) of the pattern forming means (2).
An apparatus according to any one of the preceding claims, characterized in that the hourglass-shaped rollers (7) bounding the nests (8) that form the pick-up area (3) can be driven independently of the hourglass-shaped rollers (7) disposed upstream, an article carrier (32) being provided under each nest (8) of at least the pick-up area (3), said article carriers being movable upward and downward independently of each other, the apparatus comprising a vision device (33) designed to determine the orientation of each article (V) in the pick-up area (3) and the article carriers (32) being controllable for lifting the article (V) from the relevant nest (8), depending on the orientation of the article (V) observed by the vision device (33).
An apparatus according to claim 7, characterized in that article carriers (32), movable upward and downward, are also located under the row of nests (8) located directly upstream of the pick-up area (3).
An apparatus according to claim 7 or 8, characterized in that at least each article carrier (32) located under the pick-up area (3) is rotatable around the vertical center line thereof.
An apparatus according to claim 7 or 8, characterized in that the pick-up head (13) comprises a suction cup (16) for each article (V) located in the pick-up area (3), the suction cup (16) being rotatable around a vertical center line.
An apparatus according to any one of claims 7-10, characterized in that the travelling trolley (15) carries the vision device (33), the vision device (33) being mounted at such a distance from the pick-up head (13) that the vision device (33) is located above the pick-up area (3) when the pick-up head (13) is located above the box or case (5).
A method for placing substantially spherical articles in cases or boxes (5) wherein the articles are fed to pattern forming means (2) in an unorderly manner via feed means (1); the unordered flow of articles, during feeding, is divided at an inlet of the pattern forming means (2) between a plurality of paths (2a-2e), each having a width of one article, the paths (2a-2e) comprising a plurality of nests (8) located behind one another and capable of receiving one article per nest; an article, after having entered a path (2a-2e), is accommodated in the nest (8) located most upstream and displaces an article that is already lodged therein, if any, to the nest (8) located downstream, in such a manner that the entry of a new article in a path (2a-2e) of the pattern forming means (2) results in the moving up of all articles located in said path (2a-2e) to a nest (8) located downstream; the feed of articles to a particular path (2a-2e) is stopped as soon as all nests (8) of said path (2a-2e) have been filled; if all paths (2a-2e) have been completely filled with articles, at least a part of the articles are picked up in batches from the pattern forming means (2) and placed in a box or case (5).
A method according to claim 12, characterized in that for carrying out the method, an apparatus according to any one of claims 1-11 is used.
A method according to claim 12 or 13, characterized in that the articles in the nests (8), rotating around a horizontal body axis of the articles directed perpendicularly to the path direction, are supported by rotating rollers (7), the direction of rotation of the articles being such that the sides of the articles facing upward have a speed directed in the conveying direction, the direction of rotation of the rollers (7) being reversed when all nests (8) of a path (2a-2e) have been filled.