PATTYN, Paul (Hoge Hul 4-6-8, Brugge, B-8000, BE)
| CLAIMS 1. A device (21) for separating a pre-determined quantity of piece goods comprising a conveyor belt (25) provided for supplying the piece goods and a control device (22) provided for counting the piece goods, characterized in that the conveyor belt (25) comprises a number of zones (A, B, C) situated next to one another, in that the aforementioned device (21) comprises displacement means (23) which are provided to displace at least one of the supplied piece goods from a first zone (A) to a second (B) adjacent zone as a function of the count data from the control device (22) and the predetermined quantity of piece goods. 2. The device (21) as claimed in claim 1, characterized in that the displacement means (23) are also provided to displace at least one of the supplied piece goods from the second (B) to the first zone (A) as a function of the count data from the control device (22) and the pre-determined quantity of piece goods. 3. The device (21) as claimed in claim 1 or 2, characterized in that the aforementioned zones (A, B, C) extend in the longitudinal direction of the conveyor belt. 4. The device (21) as claimed in one of the preceding claims, characterized in that the conveyor belt (25) comprises entrainment elements (26) situated next to one another, the aforementioned zones (A, B, C) being at least partially delimited by these entrainment elements (26). 5. The device (21) as claimed in one of the preceding claims, characterized in that the control device (22) is also provided for inspecting the piece goods. 6. The device (21) as claimed in one of the preceding claims, characterized in that the displacement means (23) are also provided for removing one or more piece goods from the conveyor belt (25). 7. A method for separating a pre-determined quantity of piece goods, the piece goods being supplied via a conveyor belt (25) to a control device (21) provided for counting the piece goods, characterized in that the piece goods are positioned on the conveyor belt (25) in a number of zones (A, B, C) situated next to one another and wherein, in accordance with this method, at least one of the supplied piece goods can be displaced from a first to a second adjacent zone as a function of the number of already counted piece goods and the pre-determined quantity of piece goods. |
On the one hand, this invention relates to a device for separating a pre-determined quantity of piece goods comprising a conveyor belt provided for supplying the piece goods and a control device provided for counting the piece goods. On the other hand, this invention relates to a method for separating a pre-determined quantity of piece goods, the piece goods being supplied via a conveyor belt to a control device provided for counting the piece goods.
This invention relates in particular to a device and method for separating (sorting and grouping) bakery products, preferably industrially baked and deep-frozen bread products, such as for example baguettes, baguette halves and small bread rolls.
In the world of industrial bakeries, we are nowadays confronted with a demand for online quality control of the individual products. This increased emphasis on quality control is placed above all by the customer, i.e. the wholesale distributors. Currently, only spot checks are carried out. There is therefore a burgeoning demand for a versatile, efficient control system before the product is packaged.
A second requirement imposed by today's bread industry is a markedly increased capacity. A contemporary bread counting and filling machine must be able to package maximum capacities of 12,000 units per minute.
A third discernible trend is the huge variety of different types of breads. An industrial bakery nowadays produces a broad spectrum of different products ranging from standard baguettes to ciabattas, from small table rolls to rectangular pains paves, rustic-looking breads, baps with various types of grains, etc. Specialist breads of this type are considerably more fragile and therefore also call for gentle treatment during packaging. Hence the fourth requirement concerning gentle product treatment.
The object of this invention is to provide a device and method that will rapidly separate piece goods in combination with an efficient control system. The object of the invention is achieved by providing a device and method in accordance with the claims.
In order to further clarify the properties of this invention and in order to indicate additional advantages and special features thereof, the device and method according to the invention will now be described in greater detail. It will be clear that nothing in the following description may be interpreted as a restriction of the protection applied for in the claims for this invention.
This description refers by means of reference numerals to the appended drawings, in which:
-figure 1 is a schematic illustration of a device according to the invention;
—figure 2 represents a possible displacement of piece goods on the conveyor belt in order to be able to separate a pre-determined quantity of piece goods;
-figure 3 represents another possible displacement of piece goods on the conveyor belt in order to be able to separate a pre-determined quantity of piece goods;
-figure 4 shows the alignment of the piece goods in the top-up device, fig. 4a being a side view and fig. 4b a plan view; and
-figures 5 and 6 show schematically the exchanging of a tray in the top-up device when the pre-determined quantity of piece goods has been reached in a tray.
This invention has inter alia the following objectives: increased quality control, increased capacity, huge variety of different products which have to be able to be packaged on one and the same system, emphasis on gentle treatment of the products during the packaging process.
The device according to the invention, in particular a bread filling device (21) is constructed, as illustrated in figure 1, of three partial systems: a control system (22), an ejection and batching system (displacement means) (23) and a top-up system (24), these partial systems being combined with one another in a unique and innovative manner. Moreover, new functions are assigned to the various partial systems (22; 23; 24). The partial systems are connected to one another via conveyor means, in particular a conveyor belt (25) passing through the three partial systems. The control system (22)
The first subsystem of the bread counting and filling machine (21) consists of a control device (22) provided for counting and inspecting the supplied piece goods. The control device (22) is preferably an X-ray apparatus (X-ray detector). The X-ray apparatus is the "eye" of the displacement means (23), preferably a robot (second partial system) and performs inter alia the following functions:
Checking for contaminated products
The X-ray detector (2) allows the following contaminations to be detected:
- breads contaminated with metal, hi the case of metal, the system will operate independently of the temperature of the bread and relatively small metal particles (as small as 0.6 mm) can be identified. Conventional metal detectors have a detection range down to 2 mm and are very sensitive to the differences in temperature of the bread to be monitored;
- breads contaminated with glass, hi the case of glass, the system can operate to a depth of 2 mm;
- breads contaminated with stone.
With respect to the X-ray detector (22), the conventional metal detectors have a number of important drawbacks;
- they are very sensitive to changes in temperature of the product to be inspected. Frequent calibration is therefore also essential in a situation in which the temperature of the deep-frozen bread is not always stable;
- the conventional metal detectors, which operate based on the principle of a disturbance of the electrical field, are unable to detect contaminations of 0.6 mm;
- different metals have different sensitivities; in other words, the size of the smallest particle to be detected is dependent on the type of metal;
- the orientation of the contamination in the product also influences the sensitivity;
- metal detectors can only detect metal. Other extraneous materials, such as glass and stone, cannot be identified.
Checking for shape X-ray (22) allows each product to be checked online for length, width and shape. Tolerances of this shape check are insensitive to shadows. Compared to conventional camera systems, X-ray does not suffer from shadow formation which greatly impedes image processing.
Online weight check
The X-ray (22) is also able to verify online the weight of each separate product. The tolerance of the weight recording is accurate to within one gram. Conventional solutions require what are known as online check weighers wherein the products must be positioned sufficiently far apart to allow individual weight recording. In the system described in the present document, products can even be individually weighed back-to-back.
The counting
Because the X-ray (22) identifies each product separately, it is also able to count them. In other words, it can serve as the "eye" of the displacement means (23), in particular the robot. The robot (23) is informed of the position of each product via a matrix. In addition to the position, the necessary information concerning each product is also passed on. This information may for example be: is the product contaminated? Are the weight and shape tolerances OK?
For evaluating the information originating from the control device (22), the device according to this invention is provided with an evaluation unit. The displacement means (23) will react (for example displace piece goods on the conveyor belt (25) or displace piece goods from the conveyor belt (25) to a waste container, for example, in order in that way to remove contaminated piece goods or piece goods which do not meet the quality requirements set (imposed)) as a function of the evaluated data.
The displacement device (the robot) (23)
The second subsystem of the bread counting and filling machine (21) consists of a robot (23) equipped with a suction path in order to handle the breads. The displacement device (the robot) has three important functions:
Ejection of products
If a bread is not satisfactory, it is removed. A distinction is drawn between contaminated products and products that do not satisfy shape or weight conditions. Contaminated products are deposited in a special, locked ejection bin. A different ejection bin is used for products displaying shape and weight deviations.
Compared to the conventional ejection systems currently used in the bread industry, the use of a robot has the major advantage that only rejected products are removed. A conventional ejection system uses a retractable belt (or sheeting belt). In this system, it is inevitable that good products are also removed. The problem of false ejection is therefore solved.
Grouping in accordance with the required number
On the basis of the information originating from the X-ray, the robot (23) can take the necessary action to ensure that the products are grouped in accordance with their pre-set numbers.
The following clarificatory example will distinguish between the following product groups: a. baguettes, b. baguette halves, c. small bread rolls.
A belt (25) with entrainers (26) (entrainment elements) is used for conveying the breads through the X-ray (22) and robot station (23). The breads are thus positioned, as illustrated inter alia in figures 2 and 3, between the entrainers (26). The entrainment elements (26) may be regarded as elevations extending over the length of the conveyor belt (25) at regular distances from one another transversely to the direction of movement of the conveyor belt (25). An entrainment element (26) can be formed by a continuous elevation (edge) extending over almost the entire width of the conveyor belt (25) but can also be formed by an elevation which is interrupted at a number of locations.
Zones (indicated by reference symbols A, B, C) which are situated next to one another on the conveyor belt (25) are formed by placing one or more entrainment elements (26) over the length of the conveyor belt (25) at regular distances next to one another, the various zones being demarcated (delineated) by the entrainment elements (26) positioned next to one another.
Once the robot station (23) has been passed, an entrainer (26) must in each case form the dividing line between two successive groups of breads of the stated number.
In the case of baguettes, this is not a problem because these products are positioned one-by-one between the entrainers (26).
For baguette halves, the robot (23) must ensure that two breads are in each case positioned one next to the other between the entrainers (26). That means that the robot (23) will occasionally have to carry out corrections in order to achieve this.
For small products positioned at random between the entrainers, the correct batch number is obtained by moving products in accordance with a defined algorithm of the entrainer (26) in order in this way to obtain the correct number of products within a total number of entrainers.
In other words, the surplus number is transferred to the following batch. The deficit number is added to the preceding batch.
The illustration in figure 2 represents a snapshot from before and after the correction in order to obtain a batch number of 20 items. It demonstrates how the deficit number of one item (namely bread roll no. 20) is added to the preceding batch (B). The displacement from the first zone (A) to a second adjacent zone (B) takes place with the aid of the displacement means (23); for this purpose, the displacement means (23) preferably comprise a gripping device provided to displace in each case one piece good (bread roll) from a first zone (A) to a second zone (B).
Another possible displacement is represented in figure 3 which shows how an excess of two breads (namely bread rolls 1 and 2) is added to the following batch (A).
The advantage of a batching system (sorting system) of this type over the existing systems is that even back-to-back products can be individualized. Moreover, the predetermined quantity of piece goods can be delivered at all times to the top-up device (24). The displacement means (23) will also ensure that sites that are empty (for example as a consequence of the removal of a contaminated bread roll) are resupplied with a piece good; this helps to increase the capacity of the device (1). An additional advantage of the displacement means (robot) is the fact that products can be sampled at preprogrammed moments; that is to say that products can be removed at random from the product flow for analysis purposes.
The top-up system (24)
The third subsystem relates to the top-up station (top-up device) (24). In this station a tray is filled that will afterwards carefully deposit the breads in the packaging (for example a cardboard box). In order to limit the height from which the products fall into the tray, the tray will slowly descend during the filling. Once the tray contains the correct number of breads, it descends down to the bottom of the cardboard box and opens up in order in this way to carefully deposit the products in the box.
For product groups a and b (as described hereinbefore), the products are topped up in the tray in "marshaled" form; for product group c, the breads are topped up in bulk form.
Alignment of the products
In order to neatly align the first two product groups, these products are lined up (as illustrated in Figure 4) via a lateral guide during the upward movement of the entrainers (26). In the case of baguette halves, a guide device, which presses the breads together so that they fit into the tray, is even provided on both sides.
Exchanging a tray when the desired number has been reached
The topping-up of the trays is a continuous process; in other words, the supply belt (25) continues to supply bread to the two trays. When the correct number has been reached in one tray, then the other tray must be filled straight away. During filling of the second tray, the first tray can then deposit the breads in the box and carry out a box exchange. An empty box is then available again. The same procedure applies when the second tray is full. When the correct number has been reached in one tray, then the flow of bread must be rerouted at the correct moment to the other tray. For this purpose, use is made of a triangular plate (27) which can move horizontally back and forth between two falling breads. Because it is very important that the breads fall at a constant and identical rate, a downward kink is provided in the supply belt (25). As a result, the breads slide downward between the entrainers (26) and are in this way aligned against the back of the preceding entrainer. At a constant speed of the supply belt (25), this ensures that the breads fall at a constant rate. This allows the triangle to react at the correct moment. Figures 5 and 6 represent this.
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