Conveyor system for grouping products issuing from different sources
The invention relates to a method presented in the preamble of the ap- pended claim 1 for grouping products issuing from different sources. The invention relates also to a conveyor system which is of the type presented in the preamble of the appended claim 12.
A central problem in handling products originated in connection with production or located in a storage is their transfer from their original sources, for example production locations or a storage area, to transportation to customers. There can be several types of products, which are used to form delivery packages containing one product or such delivery packages which contain several different products.
In practice, this product control during the transfer has taken place in such a way that products different from each other are brought from different sources to a grouping section, in the beginning of which there is a conveyor transferring the products forward towards several group- ing or accumulator conveyors. At the end of the conveyor, the products are distributed on these accumulator conveyors in such a way that one accumulator conveyor always contains identical products one after the other. The grouping section is followed by a station for forming product packages, where the product groups issuing from the accumulator con- veyors can be handled to form the desired packages. At the end of the accumulator conveyors, there can be for example a transverse conveyor, which receives a product batch issuing from a particular accumulator conveyor and conveys it to the packaging device.
At the beginning of the grouping section, it is possible to bring products in random order onto one conveyor, from which they are sorted out to several parallel accumulator conveyors, which contain identical products one after the other in quite long lines ready to be packaged. Due to the several parallel conveyors, such a system has a good capacity, the system is considered practical and it is well-established. Until now, however, attention has not been paid to the space occupied by the grouping section horizontally in premises where products are being handled.
The need for space results in particular from the space occupied by several parallel accumulator conveyors. The increase in the capacity produced by several accumulator conveyors is also seeming, because the speed of handling the products depends primarily on their packaging rate. Therefore, it could be said that the products often tend to lie a long time on the accumulator conveyors, and in fact, the conveyors provide a kind of an intermediate storage in the product handling premises, from which storage products are picked up according to the rate of forming product packages. A kind of an intermediate storage idea is presented for instance in Finnish patent 73647.
European patent publication 527542 presents a system comprising several feed conveyors having a common collector conveyor, at the end of which there is a grouping station for individual products. With this system, it is possible to handle individual packages issuing in random order.
Furthermore, a conveyor system is known, in which products are car- ried on one conveyor individually parallelly to each other, wherein at the feed point a product is always transferred to a respective lane of a particular palletizer, in other words it is also basically a system with parallel conveyors.
When moving products onto the conveyor, their location in the lateral direction i.e. the "lane" has to be selected according to the point of further handling (palletizer).
The purpose of the invention is to eliminate the aforementioned draw- backs and to present a method and a conveyor system with which especially the space required in the grouping of products is reduced without affecting the capacity, which can be even increased. To attain this purpose, the method according to the invention is primarily characterized in what will be presented in the characterizing part of the ap- pended claim 1. In a grouping section, different products are carried in batches consisting of identical products one after the other, along one and the same transfer path to a packaging station, in which product packages to be sent forward are formed of these batches. In the
method, the accumulation of products is conducted already in the beginning of the grouping section, by forming batches of desired size from identical products issuing from one source. Batches coming from different sources and being different from each other, are carried one after the other along a common transfer path to the packaging station.
As for the other preferred embodiments of the method, reference is made to the enclosed dependent claims 2 to 11 , and to the specification hereinbelow.
Furthermore, the purpose of the invention is to present a conveyor system which does not take much space, but by means of which it is possible to group products for packaging with a capacity which is as good as, or even better than before. To attain this purpose, the con- veyor system according to the invention is primarily characterized in what will be presented in the characterizing part of the appended claim 12. In a grouping section, there is a group conveyor common to all different product batches and arranged to collect the products issuing from different sources in different groups containing each identical products and to carry them one after the other to the packaging station. As for the other preferred embodiments of the conveyor system, reference is made to the enclosed dependent claims 13 to 16, and to the specification hereinbelow.
By transferring different products in "bursts" of predetermined size one after the other along the same transfer path, a new idea is now being applied in the handling of goods for the first time. According to the idea the aim is to group the products into these "bursts" as early as possible, wherein it is possible to handle them in a kind of a serial transfer mode, in which different products can be kept apart from each other sufficiently well when they are travelling along the same transfer path and in which they can also be separated from each other to form packages. In the following, the invention will be described in more detail with reference to the appended drawings, in which
Fig. 1 shows a schematic view of the principle of the conveyor system and of the method as well, as seen from above, and
Fig. 2 shows an alternative embodiment of a detail of the conveyor system.
Fig. 1 presents a conveyor system according to the invention viewed from above, i.e. in the plane of the floor level of the product handling premises. The handling premises comprise several sources A — I, from which products M marked with a corresponding letter are issuing. The products are brought along their own product-specific feed conveyors, which form product-specific transfer paths 1A — 11. The feed conveyors are directed from both sides towards the group conveyor in the middle forming a common transfer path 1 for the various products. The product-specific feed conveyors connect to the group conveyor in such a way that the transfer of products M to be carried further by the group conveyor is possible.
In the case presented in the figure, the feed conveyors from different sources and the group conveyor constitute a grouping section, which is marked with a dashed line R. From the grouping section, the group conveyor transfers the products to a packaging station illustrated with the dashed line P. In the packaging station, product packages which are sent to the customers are formed of the product. The group conveyor can continue as the same transfer path 1 all the way to the packaging station P, wherein its end forms a part of the packaging station P. This end contains outlets for discharging the products M into the de- vices for forming product packages.
As can be seen in Fig. 1 , the products M are conveyed from different sources already on product-specific feed conveyors in batches SA — SI, in which identical products are one after the other in groups formed of two or more products M. There is a space between the batches on the conveyors. Thus, the products are already pre-grouped on feed conveyors coming from different sources.
Feed conveyors terminate in the group conveyor on both sides trans- versely with respect to the transfer direction of the transfer path 1 formed by the group conveyor. On this group conveyor, the product batches SA — SI are transferred in similar batches. The same group conveyor receives thus different product batches moving towards the
packaging station one after the other and being separate from each other in the transfer direction. The transfer speed of the group conveyor and its start-up and stopping can be arranged in such a way that a product batch is capable of moving from the product-specific conveyor to the group conveyor, into a free space left in it between the batches. Different transfer possibilities will be described in more detail below.
Thus, the products are in separate lines one after the other, each containing a particular product. The lines travel one after the other along the same transfer path 1 , i.e. in its longitudinal direction the same group conveyor carries, along approximately the same line or lane, successive lines following each other, which are transferred at the end to the package forming.
The group conveyor ends in the packaging station P, in which the product batches are moved away from the group conveyor sideways with respect to the transfer direction of the transfer path 1. There can be two or more points of further handling, in which the final package to be transported is formed. Fig. 1 shows how there can be two successive outlets in the transfer direction of the transfer path 1 , in addition to which it is possible to perform the removal optionally on either side of the transfer path as shown by arrows. By means of two or more successive transfer points and/or transfer to both sides, it is possible to increase the handling capacity via the two or more points of further han- dling so obtained. The movement of the group conveyor is controlled advantageously automatically in such way that its pace will be set according to the pace of the product batches issuing from the product- specific feed conveyors. Automatic control means can comprise a sensor in connection with the product-specific feed conveyor, indicating the size of the product batch issuing from the product-specific feed conveyor to the group conveyor, and in connection with the group conveyor, sensors indicating the sizes and locations of the product batches along the transfer path 1 of the group conveyor, as well as a data processing unit which, on the basis of the aforementioned data, computes the space required on the transfer path 1 in the longitudinal direction and locates the free spaces on the transfer path 1 on the basis of the locations of the product batches and moves the group conveyor so that
the free spot will be situated in the junction of the product-specific feed conveyor in which the transfer can be performed.
This is most preferable especially when using a group conveyor in which the distances between different product batches remain constant when they are moved along the transfer path 1.
Furthermore, it is profitable to take a longer view when placing different product batches on the group conveyor, wherein the batches are deliv- ered on the group conveyor in such a way that they are arranged on the group conveyor in a desired order according to the previously known contents of product packages to be formed.
In the following, some separate phases in the method according to the invention and the structures of the conveyor system therein will be discussed.
Fig. 1 illustrates the transfer of products M marked with the letter C in product batches SC from their own conveyor to the group conveyor. The transfer takes place in such a way that the conveyors move simultaneously at certain speeds and the successive products M move one by one on the group conveyor so that one after the other they form a product batch SC thereon.
Fig. 2 presents another structural alternative for the junction. A transfer path 1 C carrying products turns at the end to be parallel to the transfer path 1 formed by the group conveyor, so that the junction is formed of adjacent conveyors. The product batch SC is at the end of its own transfer path already parallel to the transfer path 1 of the group con- veyor, and the batch is transferred to the group conveyor with a sideways movement, for example by pushing it from its side with a pusher, in one step. The conveyors are standing still during the transfer phase. It is also possible that the conveyor bringing the products is in motion, if the quality of the products M allows the conveyor to be running, and products are being held in the right location with a stopper situated at the end of the transfer path 1C. Thus, products M can also be accumulated to form a longer line from which a certain number of products is transferred to the group conveyor. The size of the product batch to be
transferred can be determined by means of a transfer device, for example by means of a working width of a pusher included therein, which working width can be variable.
The product batches in the packaging station P, which are brought with the group conveyor, are packaged with a suitable packaging device. In the beginning of the packaging process, the product batches are transferred in sideways direction away from the conveyor. The transfer can take place in one group with a suitable transfer means, such as a pusher which pushes from the side of the product batch. The product batches can be arranged one after the other on a grouping base, which can be located immediately next to the group conveyor or at the end of a special conveyor. In this connection, it is also possible to turn individual products to produce a desired grouping pattern. From the grouping base the products can be moved to the final package forming, for example to a palletizer, in which the products are placed on a pallet on top of each other in layers. The resulting product packages can consist of one and the same product, wherein they are formed of product batches of the same product, or they can also be mixed packages formed of different product batches.
In the packaging station P, it is also possible to form other kinds of packages than the ones described above, and in it it is possible to use known forming devices for product packages, which form the package to be sent further according to a predetermined pattern from several similar or different product batches. Another feasible case is that the entire product package is formed of one single product batch after possible re-grouping of products.
As mentioned above, the packaging station can contain several outlets successive in the direction of the transfer path 1. Furthermore, product batches can be removed on both sides of the transfer path 1 from the same spot, by providing it with two transfer means, for example pushers, or one transfer means capable of moving the product batch on either side of the transfer path 1.
For implementing the conveyors belonging to the system, it is possible to use various known structures. The conveyors are typically conveyors
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with a fixed position which produce a determined transfer path in the handling premises of products. It is possible to use for example conveyors functioning on the basis of a continuous support, such as belt or rubber plates attached to each other, or roller conveyors, all of which can be arranged to be motor-operated and controlled with solutions of prior art. One conveyor structure can be a chute, and such inclined chutes sloping towards the group conveyor could be used for example as feed conveyors, wherein the chutes have to contain controllers for allowing a product batch of a predetermined size to pass towards the group conveyor. The conveyor can also consist of several successive conveyor sections.
The transfer paths of the conveyor system can form a certain track pattern in the floor plane of the handling room, but the conveyors do not necessarily have to travel in the horizontal plane, and there can be inclined sections or even falls, as well as ascents, between the conveyors or conveyor sections.
It is, of course, possible that there are two parallel group conveyors. Also in that case, however, they function according to the invention, in other words they contain different product batches travelling one after the other along the same transfer path, i.e. along a common longitudinally directed transfer path.
There are also other alternatives for the locations of the products along different transfer paths. Fig. 1 illustrates how the products M are located closely one after the other in different batches SA, SB, SC..., and the batches are located apart from each other. It is, however, possible that the products are apart from each other in the batches, wherein they can be grouped into a more closely connected group in the packaging station P. It is also possible that the batches are attached to each other, wherein one has to able to separate them from each other at the packaging station.
Furthermore, Fig. 1 illustrates that the batches SA, SB, SC... are formed to be separate batches already on the feed conveyors. An idea also within the scope of the invention is, however, that the batches are not formed until the products are transferred from the feed conveyors to
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the group conveyor. The products can in this case be collected in a longer line of either fixed or continuously growing size. A batch of desired size is then transferred to the group conveyor from this line.
Finally, the feed conveyors do not have to be product-specific, but different product batches can be issuing on a particular feed conveyor, which does not alter the basic idea of the invention.
The handling premises in which the transfer system is located can be a production plant, wherein the sources A, B, C are different production or intermediate storage locations, or a storage, wherein the sources A, B, C can be different parts of the storage. The products M can basically be any movable units, such as individually packaged products or packages containing several products.