The present invention relates to a method of automati¬ cally sorting sheet-like objects into bundled groups, in which the objects are advanced in rows. The invention is intended for application when sorting, among other things, computer printouts, both in a folded and non- folded state, envelopes, so-called mailers, etc.

The invention also relates to arrangement for carrying out the method.

Methods and arrangement of this general kind are known to the art. According to one known technique, the ob¬ jects are delivered to a row of mutually sequential bundling or stacking stations, in which the objects are bundled on a raisable and lowerable bottom device at respective locations, and wherein bundled objects are placed on conveyors which move along the rows of bun¬ dling statitions and later removed therefrom. This known technique is encumbered with a number of serious draw¬ backs. For instance, the arrangement of rows of bundling stations and a conveyor which is common to all said stations places serious restrictions on the speed at which the objects can be sorted, while requiring the use of an intricate control system.

The present invention provides a method and an. arrange- ment which enables the objects to be sorted very quickly and which include significant simplifications in compar¬ ison with the known methods and arrangements of the kind meant here.

Thus, the invention relates to a method of sorting sheet-like objects into bundled groups, in which the

objects are advanced in rows.

The method is mainly characterized by arranging the objects in a fishscale-like configuration in which each object is partially overlapped by an immediately preced¬ ing object, as seen in the direction of advancement, and stacking the objects together from beneath.

The invention also relates to an arrangement for sorting sheet-like objects into bundled groups which include conveyor means for advancing the objects in rows.

The arrangement is mainly characterized by devices which are active in placing the objects in a fishscale-like configuration, in which each objects is partially over¬ lapped by an immediately preceding object as seen in the direction of advancement, and by devices which are active in stacking the objects from beneath.

The invention will now be described in more detail with reference to exemplifying embodiments thereof and also with reference to the accompanying drawing, in which

Figure 1 is a schematic overhead view of a first embodi- ment of an inventive arrangement, in which the objects are moved from the right to the left in the Figure, and in which Figure no objects have been shown for the sake of clarity; and

Figure 2 illustrates the arrangement shown in Figure 1 from beneath the arrangement.

Figure 1 shows sheet-like objects 1 which are intended to be sorted by the inventive arrangement into bundles 2 in a predetermined fashion. The arrangement includes primarily an object aligning and conveying section 3 and

an object grouping section 4.

The objects can be introduced into the object aligning and conveying section 3 from the front of said section, i.e. in the main object conveying direction of the arrangement, as indicated by an arrow 5 in Figure 1, or from the side of said section, as indicated by an arrow 6 in Figure 1. The objects are brought into edge- alignment with one another in the aligning section 3 against a side bar 7 with the aid of an obliquely posi¬ tioned feeder 8, such as a belt 8, and advanced in said section towards the object grouping section 4.

The grouping section 4 is constructed to orientate the objects l in a fishscale-like configuration at that end of the section which faces towards the aligning and con¬ veying section, such that the objects will be partially overlapped by a respective preceding object, as seen in the direction of advancement. According to one preferred embodiment, the arrangement includes a braking and lifting device 10 which is passed by the objects and which functions to brake respective objects and to raise the rear part 11 of said objects, so that the immediate¬ ly following object will be partially overlapped by the braked and raised preceding object, as illustrated schematically in Figure 2. In the case of the illustrat¬ ed, exemplifying embodiment, the lifting and braking device includes roller means 12, which in the Figure 1 embodiment have the form of disc-shaped rollers 12 which rotate about an axle 13 which extends transversely to the direction in which the objects are advanced such as to lift said objects, and also braking means 14 in the form of roller means 15, which in the illustrated case have the form of disc-shaped rollers 15 which rotate about an axle 16 which extends transversely to the direction in which the objects are advanced and which

functions to slow down the objects in their respective raised positions, so that the next following object will be partially inserted beneath the immediately preceding object. The brake means or object retarding means 14 can be adjusted in the conveying direction, so as to adapt to the current sizes of the objects, as indicated by the double-headed arrow 17 in Figure 1.

The illustrated arrangement also includes a stacking or bundling device 18 which functions to stop the fish- scale-configured stream of objects so as to form a bundle 2, as a result of following objects being contin¬ uously inserted beneath preceding objects which have been stopped by the stacking device 18 and therewith form a stack or bundle of objects, as shown schematical¬ ly in Figure 2. In the case of the illustrated, pre¬ ferred embodiment, the stacking device includes a forked member 19 which is provided with upwardly turned stop shoulders 20 against which the objects are intended to be stopped. The forked member 19 is pivotal about an axle 21 which extends transversely to the object convey¬ ing direction and which is intended to be held in a stop position by means of a spring force, and which is rotat¬ ed counter-clockwise in Figure 2 against said spring force by means of an electromagnetic pulling device 22, wherein the stop shoulders are intended to be lowered so that the objects/bundles that are stopped by the stop shoulders can be released for further transportation.

As will be seen from the drawing, the arrangement in¬ cludes a grouping device 23 which is located upstream of the stacking device and which functions to stop the flow of mutually overlapping objects so as to create an interruption in the flow upstream of said stacking device, this interruption being intended to delimit two mutually sequential groups of objects, as shown schemat-

ically in Figure 2.

The grouping device includes a forked member 19 of the same kind as that included in the stacking device for s ^h opping and releasing objects.

T- illustrated arrangement also includes a first sensor 24 -iich detects the last object 1' that is allowed through by the grouping device prior to an interruption and which also sends to the grouping device a signal in¬ structing the device to release the stream of objects. The arrangement also includes a second sensor which detects the last object 1' to be allowed to pass through and also functions to send to the stacking device a signal instructing said device to release the bundle 2 ' in which the object 1' is at the bottom ofthe bundle. The arrangement also includes a third sensor 26 which detects when the bundle 2 ' has been released from the stacking device and has left the device, and functions to send to the stacking device a signal which causes the stream of objects to be stopped and a further bundle formed.

The grouping device is constructed to be activated in a manner to cause an interruption in the stream of objects in receipt of a signal sent from a sign reader 27 which is located upstream of the grouping device and which functions to distinguish between the different objects in the object stream by means of distinguishing marks on said objects and/or by means of a height detecting means 28 which functions to detect the height of a bundle formed in the vicinity of the stacking device.

The aforesaid last object 1' which is allowed to pass through is drawn past the grouping device by means of rollers 29.

A fourth sensor 30 is provided in the vicinity of the object braking and lifting device and functions to detect errors in the fishscale-like configuration of the objects and to send a signal to the grouping device instructing said device to stop the stream of objects when such a fault is detected.

The reference numeral 31 identifies belts which form part of a grouping section conveyor 32, which is active to draw, convey, the objects through the grouping sec¬ tion.

The method according to the present invention and also the manner of operation of the inventive arrangement will be understood in all essentials from the afore¬ going. Thus, subsequent to the objects being brought into edge-alignment, the objects are arranged in a fishscale-like configuration and stacked together from beneath in the stacking device, in which the objects are stopped. The stream of mutually overlapping objects is divided by the grouping device into bundles which corre¬ spond to different groups or classes of objects.

It will also be understood that the invention enables objects to be sorted quickly and reliably. The invention has been described in the aforegoing with reference to mainly one embodiment thereof. It will be understood, however, that other embodiments and minor modifications are conceivable, without departing from the inventive concept.

The devices 24, 25, 30, 26, 27, 28 for detecting ob¬ jects, bundles, distinguishing between the different objects and for detecting the heights of the bundles are suitably of a known kind.

According to one preferred embodiment of the invention, the sign reader 27 is an optical reader, for instance a black/white reader, for contactless detection and iden¬ tification of signs or markings on the objects and/or for counting the objects.

Similarly, according to one preferred embodiment of the invention, the sensors 24, 25, 26 and 30 include photo- readers which detect reflected light and therewith detect whether or not an object is located in the posi¬ tion monitored by a respective sensor.

The height detector 28 will preferably include level sensors which function to detect bundle height, and particularly when a predetermined bundle height has been reached, said level sensors being arranged essentially transversely to the height direction of the bundle 2 ' . The level sensor 28 may also be of a kind which includes distance measuring means active in measuring the dis- tance to the upper surface of the bundle 2 ' .

The inventive arrangement may include a more or less intricate control system, not shown. In the case of the aforedescribed embodiment, it is possible to avoid the need for a main or supervisory control system, since the different sensors are able to control the process of sorting the objects into respective bundles and groups in an unequivocal manner. The control system may, in the present respect, include devices which enable the divi- sion of the objects into groups in response to a signal delivered by a level sensor 28 or a sign reader 27, or by both in combination. A more active control system can also be envisaged, in which the conveying speed of the conveyor 32 is detected by means of a pulse disc or in some other suitable known manner, and in which, among other things, predetermined delays are introduced while

taking the conveyor speed into account, so as to achieve the aforedescribed working method of the arrangement.

As will be understood from the aforegoing, one sorting criterion with regard to the division of bundled groups can be the type of object concerned, so that different types of objects will be sorted into respective differ¬ ent bundles and/or the division can be effected in accordance with the height of the bundles, so that the objects will be sorted into bundles of predetermined heights. Another sorting criterion which can be used separately or in combination with one or more of the other criteria may be the number of objects concerned.

The invention is thus not restricted to the described and illustrated embodiments, since variations can be made within the scope of the following Claims.