FR2644761A1 - Device for conveying small boxes - Google Patents

Abstract

Device for conveying small boxes between an entry station and an exit station. According to the invention, this device is characterised in that it includes a conveying track 13, formed from two spaced slideways 14, 15, on which the base 17 of the small boxes 1 rests, at least one permanently controlled drive belt 21 extending parallel to the base of the small boxes, this belt being adapted to bear temporarily against this base through the effect of at least one movable bearing roller 36, producing the entrainment of the small boxes individually and slightly raising the belt, this roller being integral with a swing tray composed of an arm 26 tilting about a fixed transverse shaft 27, the arm being equipped at one end with a counterweight 28 and at the other with an inclined lever 31 projecting upwards between the slideways in front of the bearing roller relative to the direction 30 of displacement of the small boxes over these slideways such that any small box, entrained by the belt, is displaced over the slideways until it gives rise to the tilting of the inclined lever, causing the swing tray to pivot downwards in order to retract the bearing roller and eliminate the contact of the belt on the base of the next small box, stopping its entrainment over the conveying track.

Description

 The present invention relates to a device which makes it possible to ensure the step-by-step conveying of boxes or similar receptacles, intended to contain envelopes, letters or other flat objects of the same kind, of various sizes and placed in a stack in these boxes without having necessarily undergone a preliminary sorting, these letters being, in a first station, extracted from the boxes to be sorted in a separate installation according to their destinations then, once these operations carried out and in a second station, replaced in these box seines , the device being arranged to transfer the boxes from the first station where they are emptied to the second station where they are again folded by the sorted letters.

 The subject of the invention is an automatic transfer device for such empty boxes (or not) between the two stations, making it possible to convey, store and finally deliver these boxes according to a new intermittent advance such as a box, once emptied in the first station or entry station, i.e. iDoédiaterent resumption and sent to the second station or exit station in a waiting position and prior storage, before entering on demand in this second station to be then folded by the sorted letters.

 According to the invention, the device considered is characterized in that it cosports a conveying track, drilled with two spaced slides on which the bottom of the boxes rests, in the poins a drive belt permanently controlled and extending parallel to the bottom of the boxes, this belt being adapted to come to bear temporarily against this bottom under the effect of monks a movable support roller, carrying out the training of the boxes individually, by slightly lifting the belt, this roller being integral with a swing made up of an arm rocking around a fixed transverse axis, the arm being provided at one end with a counterweight and at the other with an inclined lever, projecting upwards between the slides forward support roller relative to the direction of movement of the boxes thereon so that any box, driven by the belt, moves on the slides to the xosent where it causes the tilting lever to tilt by pivoting the swing down to clear the support roller and remove the contact of the belt on the bottom of the next box, stopping its drive on the conveyor track.

 Advantageously, the successive boxes in movement on the conveyor track are guided laterally by reievés edges provided on each side of the slides. Furthermore and according to a characteristic of the device considered, the conveying track has at the end a stop on which the first box rests at the end of the track, said stop being retractable on demand, to release the box towards the station. outlet where it is associated with filling means, by letters or other similar flat objects.

 According to another characteristic of the device considered, the conveyor track comprises a plurality of rollers, each spaced along the following by a distance substantially equal to the length of a box in order to allow step by step the advance of the boxes on the track úsuntil the stop at the end of the track, following the erasure step by step of the successive swings as the boxes advance.

 The conveying device according to the invention thus allows a set of boxes arranged in a line, to be one to one supported on the slides1 the successive swings arranged under the boxes, disappearing as the advance of the latter and the addition on the track each time of an additional box, which is added behind the boxes already in place, the first of these in the direction of movement acting on the next swing and so on, step by step, until this first box comes to bear against the stop at the end of the conveying track.

 The request for a box by the exit station causes in the line of boxes a hole (the length of a box) and a loosening of the swing. Simultaneously, it is raised by engaging the advance of the previous box which progresses to the next step and so on throughout the conveyor.

 In a preferred embodiment of the invention, the inclined lever of each swing has a U-shape, the two branches of which are secured to the rocking arm, the central part of the lever also being slightly folded down to allow free movement sliding of the boxes on the slides.

Other characteristics of a device for conveying boxes, suitable in particular for being used in a postal sorting installation, will become more apparent from the following description of an exemplary embodiment, given by way of non-limiting indication, with reference to the accompanying drawings in which
- Figure 1 is a schematic view of a sorting installation, implementing a device according to the invention.

 - Figures 2 and 3 are elevation views on a larger scale, illustrating a swing of the conveying device respectively in two positions, depending on whether a box driven by the device acts or not on its inclined lever.

 - Figure 4 is a top view corresponding to Figures 2 and 3, illustrating in particular the shape of the inclined lever of the swing.

 - Figure 5 is a detail view å even larger scale, schematically the device for driving boxes on the conveyor track.

 - Figure 6 is a sectional view on a smaller scale, contrent input is carried out the lateral guidance of the boxes.

 - Figure 7 illustrates more specifically the stop provided at the end of the conveying track and the means which allow its erasure for the extraction of the first box from the device.

 The diagram in FIG. 1 very generally illustrates a sorting installation for boxes such as 1, previously filled with flat objects of the type of letter envelopes or the like 2. The boxes 1 move on a conveyor belt 3 according to the direction of the arrow 4, this mat being associated with means which, as required, make it possible to come and take a given box from the mat and bring it to a first station or entry station 5 in which the box 1 considered can be emptied of its letters 2. These are taken one by one in a drive device 6 to be routed to a processing and sorting unit 7, the detail of which is of little importance to the present invention. This assembly 7 can thus include a device for stacking and unstacking the letters 8, making it possible to distribute them with a given speed and spacing in front of one or more indexing heads 9, the letters 2 thus indexed then being routed and distributed in a series of receiving bins 10, where they are grouped according to their destinations and possibly their formats. Once any one of the trays 10 has thus been filled, the sorting device 7 is provided so that the driving device 6 ensures the evacuation of the letters 2 contained in this tray and their successive recovery in order to send them back to a second or exit station 11, in which an empty box 1 has previously been disposed. Once the letters thus sorted collected in the box, once full is returned to the conveyor belt 3 which routes it to a appropriate distribution center, not shown here.

 The boxes 1, received full at station 5 and emptied of their letters therein, are then forwarded to station 11 to be filled there again in the manner mentioned above, by means of a conveying device 12, more specifically forming the subject of the present invention and the detail of which will now be explained with reference to FIGS. 2 to 7.

The boxes 1 are introduced one by one onto this device from station 5, this device being designed so that the arrival on it of a new box pushes the box or boxes already in place and so on until 'At the end of the conveyor close to station 11, into which these same boxes can then be introduced one by one as the installation requires.

 As can be seen more particularly in FIGS. 2 to 4, the device 12 mainly consists of a conveying track 13, comprising two horizontal and parallel slides 14 and 15, spaced from one another and extending along the entire length of the device between stations 5 and 11. These slides are provided to support the boxes 1, engaging in grooves 16 (FIG. 5>, formed under the bottom 17 of these boxes. The slides 14 and 15 are themselves fixed on a rigid support casing 18, comprising two lateral vertical edges 19 and 20 respectively (FIG. 6), so as to allow the guidance of the boxes 1 during their movement on the conveyor track 13.

 The driving of the boxes on the slides 14 and 15 is carried out by means of a belt 21, (in reality by means of two parallel belts 21a and 21b) disposed between these slides under and parallel to the bottom 17 of the boxes, these belts being stretched between return pulleys 22 Cfigure 7) and permanently driven by a drive pulley 23, connected by a 20toréducteur 24 fixed on the chasies 18.

 At rest, the upper strand of the belt 21 is, by construction, located at a level very slightly lower than that of the plane materialized by the slides 14 and 15. Under these conditions, the drive of any box 1 put in place on these slides, requires that the belt 21 be properly lifted to come into contact with its bottom 17, the material of the belt being chosen so that it allows, by simple friction on this bottom, the displacement of the box1 carried out as long as this contact is maintained.

 To this end, the device 12 comprises a step-by-step advance mechanism of the boxes 1 on the track 13, constituted by a plurality of successive swings 25, each of which is arranged so as to limit the movement of the boxes one by one. given distance, corresponding substantially to the length of each of these boxes.

 For this purpose, each swing 25 consists of a tilting arm 26, articulated around a transverse axis 27 carried by the blackcurrant 18, this arm supporting at its posterior end a counterweight 28, itself articulated on the arm around an axis 29, parallel to the axis 27. At its rear end, in the direction of movement of the boxes on the track 13 shown diagrammatically in FIGS. 2 b 4 by the arrows 30, the arm 26 comprises a lever 31, consisting of a first part 32 connected to the arm and extending substantially in the extension thereof, then of a second part 33 inclined upwards, forming an elbow with the first and directed between the slides 14 and 15.

Advantageously, the second inclined part 33 has one end 34 curved downward so as not to hinder the movement of the boxes.

 More specifically against FIG. 4, each swing 25 is thus capable of oscillating around the axis 27 in the region 35 left free between the two slides 14 and 15, the counterweight 28 being determined so that, in the absence of boxes on these slides, the inclined portion 33 of the lever 31 extends above these slides beyond the horizontal plane in which they are mounted. Each tilting arm 26 also includes a support roller 36 provided on this arm opposite the counterweight 28, preferably in the region where the lever 31 is connected to the arm. This roller 36 (in reality consisting of two parallel rollers 36a and 86b mounted at the ends of a transverse support 37) is provided to cooperate with the belt 21 (the rollers 36a and 36b applying under the strands respectively 21a and 21b of this belt) in order to cause, depending on the position of the lever 31, the limited lifting of the belt or on the contrary its reldchelrent, with -in the first of these positions, the displacement of the corresponding box and in the second its isobillation.

 Gr b these provisions, we understand that the advance of any box on the slides 14 and 15, caused by the introduction on track 13 of a new box from station 5, determines the lowering of the corresponding swing 25 as soon as the front part of the first box abuts on the inclined part 33 of the lever.

Simultaneously, the support roller 36 is lowered due to the tilting of the arm 26, causing the loss of contact of the belt 21 vis-à-vis the bottom 17, the box 1 then being immobilized by a motorized nano due å the presence of a previous box. When a new new box is added to the previous ones, then immobilized, this advances as long as the belt 21, then in the raised position, bears against the bottom 17 of this small box to drive it one step on the runway. conveying 13 the isobilisation of the box then intervenes immediately after.

 Gradually, the boxes 1, in continuous file on the conveyor track 13, thus advance step by step as they are introduced from station 5 to the immediate vicinity of station 11 and stopped in this position by a retractable stop 38 whose Figure 7 illustrates more particularly the embodiment. This stop 38 includes in particular a hook 39, joined to a support 40 articulated around an axis 41, this support 40 being provided with a roller 42 suitable for coming to cooperate with the belt 21 in a similar manner to the rollers 36 seen previously. The support 40 is itself articulated at its opposite end about an axis 43 on the rod 44 of a jack 45 carried by the blackcurrant 18.

 When the stop 38 is in the raised position, it thus immobilizes the first box 1 and behind it all the boxes present on the conveyor. In this position, the roller 42 is lowered and does not apply the belt 21 under the bottom 17 of this first box. On the other hand, when ~ when it is necessary to penetrate the box into the station 11, the actuator 45 is controlled in the direction where its rod 41 swings the support 40 around the axis 41, here in the opposite direction of Clockwise. In this movement, the roller 42 lifts the belt 21, at the same time that the hook 39 is tilted down. The box 1 driven by the belt can in these conditions leave the track 13 and come to be placed in the station 11, the second box following the first being simultaneously controlled by the raising of the corresponding swing 25 until taking the place of the previous, pressing against the stop 38 previously raised.

 This produces a device for conveying boxes allowing, thrush to successive swings distributed along the length of the track, a continuous step-by-step advance of these boxes, each of them being driven by the belts carrying under its bottom as and measure that it lowers a swing, causing the limited support of the belt support roller to be raised simultaneously. This device avoids permanent friction of the belts under the bottom of the boxes once they have been stored and moved on the conveyor track, boxes being awaiting their call one by one on the exit station provided at the end of the conveyor thanks to the appropriate control of a retractable stop. The swings are arranged in such a way that they automatically rearrange the support rollers once the box concerned has passed each of these swings successively, allowing the next box to be driven until it stops on the line of boxes two in waiting on the conveyor track.

 Of course, it goes without saying that the invention is not limited to the single embodiment described and shown above; on the contrary, it embraces all its variants.

Claims (6)

 1 - Device for conveying boxes between an entry station and an exit station, characterized in that it comprises a conveying track (13), formed of two spaced slides (14, 15) on which the bottom rests ( 17) of boxes <1), at least one drive belt (21) permanently cown and extending parallel to the bottom of the boxes, this belt being adapted to come to bear temporarily against this bottom under the effect of at least a movable support roller (36), carrying out the driving of the boxes individually by slightly lifting the belt, this roller being integral with a swing composed of a rocking arm Q6) around a fixed transverse axis t27), the arm being provided at one end with a counterweight Q8) and at the other with an inclined lever (31) projecting upwards between the slides in front of the support roller with respect to the direction (30> of displacement of the boxes thereon so that a box Any one, driven by the belt, moves on the slides until it causes the tilted lever to tilt by pivoting the swing down to clear the support roller and remove the contact of the belt on the bottom. from the next box, stopping its drive on the conveyor track.  2 - Conveying device according to claim 1, characterized in that the successive boxes moving on the conveying track are guided laterally by raised edges (19, 20), provided on each side of the slides.  3 - Conveying device according to one of claims 1 or 2, characterized in that the conveying track has at its end a stop <38) on which the first box rests at the end of the track, said stop being retractable on demand to free the box towards the exit station <11).  4 - Conveying device according to any one of claims 1 to 3, characterized in that the conveying track comprises a plurality of support rollers <26) each spaced along the following by a distance substantially equal to the length of a box.  5 - Conveying device according to any one of claims 1 b 4, characterized in that the inclined lever (31) of each swing has a U-shape whose two branches are secured to the rocking arm, the central part (34) of the lever being slightly folded down.  6 - Conveying device according to claim 3, characterized in that the stop (38) comprises a stop hook (39) of the first box secured to a support (40) articulated around a fixed axis <41) , the tilting of the support being achieved by the rod (44) of a jack (45) causing the erasing of the hook siiultanêment with the raising of a support roller (42) on the belt (21) determining the advance from the first box to the exit station.