This invention relates to an apparatus for processing a plurality of flat articles, such as envelops and postcards, and more particularly to an apparatus for feeding flat articles, one by one.
A feed apparatus of this kind is utilized, for example, in a mail sorting system. A plurality of flat articles (such as postcards and envelopes) are arranged in a stacker and are fed one by one to an address reading section and a sorting section. There are two feeding modes, i.e., a front-aligned feeding mode, in which a plurality of flat articles are arranged with their front ends aligned are fed one by one, and a rear-aligned feeding mode, in which a plurality of flat articles are arranged with their rear ends aligned are fed one by one. The front-aligned are feeding mode is often employed in the case where a plurality of flat articles stacked in a horizontal state are fed one by one. The rear-aligned feeding mode is used in the case where a plurality of flat articles are stacked in a vertically standing state and are fed one by one.
The flat articles are preferably fed in such a manner that they are spaced from one another by the shortest possible distance, in order to make the most efficient use of a subsequent processing section. On the other hand, such flat articles, to be processed, have various sizes. In order to feed flat articles one by one at a regular pitch, in either the front-aligned feeding mode or the rear-aligned feeding mode, it is necessary to set the regular pitch to a suitable level, taking the size of the largest flat article into consideration. If the regular pitch is set in this manner, the flat articles are necessarily fed at unduly long intervals when there is a high percentage of smaller-sized flat articles.
In the front-aligned feeding mode, the flat articles are practically fed in such a manner that they are spaced from one another by the shortest permissible distance. The next subsequent flat article is delivered, for feeding when a predetermined period of time has elapsed after the detection of a rear end of a previously-fed flat article. Therefore, the flat articles can be fed easily, at the possible shortest interval. As mentioned above, the front-aligned feeding mode is used frequently when flat articles stacked in the horizontally state are fed. However, the flat articles stacked in a vertically standing state can not be fed at the possible shortest interval. In this case, i.e., in the rear-aligned mode, an interval does not become constant between each of the adjacent flat articles, even if a subsequent flat article is delivered for feeding when a predetermined period of time had elapsed, after a front end of a previously-fed flat article was detected.
Accordingly, when the plurality of flat articles are arranged in a vertically standing state and are fed in the rear-aligned mode, the capacity of a subsequent processing section cannot be fully utilized since flat articles cannot be fed as they are kept spaced at the possible shortest interval.