The invention relates to a method for storing and afterwards collecting orders, consisting of articles packed in crates or plastic baskets.
Particularly in the United States of America there are many companies which pack their products in crates or baskets, which are formed to stacks, which stacks are then placed for transport on e.g. dolly's, i.e. low carts having two or more swivelling wheels, or further conveyed over driven conveyor tracks recessed into the floor.
These stacks, which will be called full stacks from now on, as a rule have a height corresponding to the available height in the trucks, with which these stacks are transported to the buyers. In dairy factories, these stacks generally comprise six crates, but in bread factories and the like they comprise a larger number of baskets, often sixteen.
Since these stacks are formed shortly after the packing line, they consist of crates, boxes or baskets containing only one type of article, e.g. only whole milk. However, a buyer often orders a great variety of articles. The number of crates containing one type of article that has to be delivered, is generally smaller than the number of crates in a full stack.
Therefore the stacks formed after the packing line have to be conveyed to a spot where a large part of these full stacks has to be destacked in order to form full stacks again together with numbers of crates containing another article on the basis of the order forms.
Would the stacks have been smaller, then it would more often occur that a once-formed stack does not have to be destacked because the smaller number of crates of these lower stacks, which contain the article in question, does not exceed the number of crates ordered. At the most, a few crates have to be added. It is very useful to choose such a height for these smaller stacks, which will be called partial stacks from now on, that two or more partial stacks together form a full stack.
The partial stacks could have the drawback that if large quantities of one type of article have to be delivered, these partial stacks have to be stacked to form full stacks. This is not necessary if the crates are stacked to full stacks at once. However, internal conveyance of full stacks often causes damage due to toppling over. Now it is an important advantage that the partial stacks are far more stable and cannot cause damage due to toppling over.
The invention relates to a method for storing and then collecting orders, consisting of products packed in crates or baskets and the like, with the aid of a staging, comprising storage conveyors positioned in rows adjacent to and in layers above each other, on the one side of the staging at least one supply conveyor and at least one entry elevating device, being movable along the staging and comprising an introducing device and a driving means for the conveyance over the storage conveyors and on the other side of the staging at least one discharge conveyor and at least one exit elevating device, also being movable along the staging and comprising a removing device and a driving means for the storage conveyors.
Such a method is known from Dutch application Nos. 80,01352 and 80,04549, now European Patent No. 00 35818, and now U.S. Pat. No. 4,712,964; which is incorporated herein by reference, in which only single crates are stored and from which all the orders are compiled. Although very suitable in those cases in which the orders consist for the greater part of one or a few crates or baskets, this installation is expensive due to the manner of storing and the large number of storage tracks required especially in those cases, in which the orders substantially comprise a plurality of crates per article.
The invention aims to remove the drawbacks of this known method.