WO1993015006A1

WO1993015006A1 - Method of and apparatus for automatic sorting of sheetformed objects

Info

Publication number: WO1993015006A1
Application number: PCT/SE1993/000051
Authority: WO
Inventors: Nils Jonny Mejdahl; Per Gunnar Swartz
Original assignee: Nils Jonny Mejdahl; Per Gunnar Swartz
Priority date: 1992-01-29
Filing date: 1993-01-25
Publication date: 1993-08-05
Also published as: EP0624144A1; SE9200249L; EP0624144B1; SE9200249D0; DE69318544D1; AU3465993A; SE469798B

Abstract

The invention relates to sorting sheet-like objects (1) into bundled groups (2) in which the objects are advanced in rows. The method is mainly characterized by orientating the objects into a fishscale-like configuration in which the objects are inserted partially beneath a respective immediately preceding object, as seen in the direction of advancement, and stacking or bundling the objects (1) from beneath. The invention also relates to arrangement for carrying out the method.

Description

Method of and apparatus for automatic sorting of sheetformed objects

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^hopping 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.

Claims

1. A method for sorting sheet-like objects into bundled groups, in which the objects are advanced in rows, c h a r a c t e r i z e d by arranging the objects in a fishscale-like configuration in which a following object is partially inserted beneath a respec¬ tive preceding object as seen in the direction of ad¬ vancement, and by stacking the thus orientated objects from beneath.

2. A method according to Claim 1, c h a r a c ¬ t e r i z e d by passing the row of objects through a lifting device (12, 13) which functions to hold the rear part (11) of respective objects in a raised position while the next following object is inserted partially beneath the lifted part of the immediately preceding object.

3. A method according to Claim 1 or 2, c h a r a c ¬ t e r i z e d by halting the stream of mutually over¬ lapping objects with the aid of a stacking device (18), and forming a bundle of objects (2, 2') by continuously inserting objects beneath preceding stationary objects, to form a bundle or stack.

4. A method according to Claim 1, 2 or 3, c h a r a c t e r i z e d by releasing a bundle (2, 2') containing a predetermined number of objects through the agency of the stacking device, and transporting said bundle away.

5. A method according to Claim 1, 2, 3 or 4, c h a r a c t e r i z e d by halting the flow of par- tially overlapping objects with the aid of a grouping device (23), such as to interrupt the flow of objects, this interruption mutually separating two mutually sequential groups of objects.

6. A method according to Claim 5, c h a r a c - t e r i z e d by detecting the last object (1') that the grouping device allows to pass through prior to an interruption, wherein the stream of objects is released by means of the grouping device when said last object has passed a predetermined position between the stacking device and the grouping device; and by releasing the bundle (2') in which said object forms the bottommost object, through the agency of the stacking device, whereafter the object stream is again halted by means of the stacking device.

7. A method according to Claim 1, 2 , 3, 4, 5 or 6, c h a r a c t e r i z e d by activating the grouping device to cause an interruption in the object stream in response to a signal delivered by a sign reader (27) which is located upstream of the grouping device and which functions to detect the nature of the objects in the object stream and/or count said objects (1), and/or delivered by a height detector (28) which functions to detect the height of a bundle formed in the vicinity of the stacking device.

8. A method according to Claim 1, 2, 3, 4, 5, 6 or 7, c h a r a c t e r i z e d by halting the stream of objects to the grouping device when a fault is detected in the fishscale-like configuration of the objects.

9. A method according to Claim 1, 2, 3, 4, 5, 6, 7 or 8, c h a r a c t e r i z e d by bringing the objects into edge-alignment against a side bar (7) with the aid of an obliquely positioned feeder (8) prior to arranging the objects in said fishscale-like configuration.

10. An arrangement for sorting sheet-like objects into bundled groups, comprising conveyor means for advancing the objects in rows, c h a r a c t e r i z e d by devices (10, 14, 18) which are active in arranging the objects (1) into a fishscale-like configuration in which an object is partially inserted beneath an immediately preceding object as seen in the direction of advancement and thereafter stacking the objects from beneath.

11. An arrangement according to Claim 10, c h a r a c t e r i z e d by a braking and lifting device (10) which is intended to be passed by said objects and which is active in holding the rear part (11) of respective objects in a raised position while part of an immediately following object is inserted beneath the raised preceding object.

12. An arrangement according to Claim 11, c h a r a c t e r i z e d in that the braking and lifting device (10) includes roller means (12) which are rotatable about an axle (13) which extends transversely to the direction in which the objects are advanced, so as to raise said objects.

13. An arrangement according to Claim 10 or 11, c h a r a c t e r i z e d in that the braking and lifting device (10) includes braking means (15) prefera¬ bly in the form of roller means (15) which are rotatable about an axle (16) which extends transversely to the direction of advancement of the objects and which func¬ tions to halt objects in a partially raised position effected by said lifting device, so that the next arriv¬ ing object will be inserted partially beneath the imme¬ diately preceding object.

14. An arrangement according to Claim 10, 11, 12 or 13, c h a r a c t e r i z e d by a stacking device (18) which is active to halt the stream of fishscale-like configured objects, such that a continuous stream of objects will be inserted beneath the preceding, station¬ ary objects to form a bundle (2, 2').

15. An arrangement according to Claim 14, c h a r a c t e r i z e d by devices (19, 20, 21, 22) which function to release a bundle of predetermined size formed by said stacking device (18), and to carry away said bundle.

16. An arrangement according to Claim 14 or 15, c h a r a c t e r i z e d by a grouping device (23) which is active to halt the stream of fishscale-like configured objects so as to create an interruption in said stream upstream of the stacking device (18) , said interruption being intended to delimit two mutually sequential groups of objects.

17. An arrangement according to Claim 16, c h a r a c t e r i z e d by sensor means (24, 25, 26) which function to detect the last object (1') which is allowed to pass by the grouping device prior to an interruption and to deliver a signal to the stacking device for releasing the bundle (2') in which the last object (1') forms the bottommost object, and to deliver a signal to the grouping device to release the stream of objects when said last object has passed a predetermined position between the stacking device and the grouping device, and to deliver a signal to the stacking device instructing said device to again halt the flow of ob¬ jects so as to form a new bundle.

18. An arrangement according to Claim 16 or 17, c h a r a c t e r i z e d in that the grouping device is intended to be activated to create an interruption in the object stream in response to a signal from a sign reader. (27) located upstream of the grouping device and functioning to detect the nature of the objects in said stream and/or to count said objects with the aid of signs or markings on the objects and/or in response to a signal delivered by a height sensor (28) which functions to detect the height of a bundle formed in the vicinity of the stacking device.

19. An arrangement according to Claim 16, 17 or 18, c h a r a c t e r i z e d by devices (30) which func- tion to detect a fault in the fishscale-like configura¬ tion of the objects and to stop the stream of objects to the grouping device when such a fault is detected.

20. An arrangement according to Claim 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19, c h a r a c t e r i z e d by an obliquely positioned feeder (8) which functions to bring the objects into edge-alignment against a side bar (7) prior to orientating said objects in said fishscale- like configuration.