EP0084495A1 - Sorting device on a horizontal conveyor - Google Patents

Abstract

Apparatus for use in an industrial operation wherein objects moving along a main path from an upstream to a downstream location are diverted to a second path for checking. The apparatus comprises an ejecting wheel for sorting objects which shall have been checked defective for some reason and preventing movement of those objects from returning to the main path.

Description

During many industrial operations, the objects handled can be transported on conveyors offering a simple horizontal support. This is particularly the case for articles such as bottles, jars or other glass containers. Their production and even more the packaging operations of the products for which these containers are intended are carried out at very high speed, in particular in the bottling and require the use of automatic machines. The machines in question, whether control, filling or capping, etc. are generally barrel machines fed by a chain of horizontal conveyors on which the articles, bottles for example, are simply placed: a wheel in star form they are taken one by one to separate them and present them in turn, continuously or step by step, at one or more work stations, before releasing them on the next section of conveyor.

At various times, it may also be necessary to refer the successive objects differently, depending on this or that criterion, to the subsequent stages of production in progress. This is particularly the case for splitting queues, grouping them on the contrary or even at the exit from checkpoints, when defective objects have to be eliminated.

We quickly thought of placing on the side of the conveyor, at a fixed position, an ejector consisting of a transverse pusher moved by a pneumatic cylinder over a distance of the order of the width or diameter of the object, or, when relatively light objects are involved, a nozzle emitting a sufficiently violent jet of air in their passage.

These devices have the advantage of a very simple construction and adapt very easily to manufacturing changes: however, they must act all the more quickly as the rate is higher, so that the action of the pusher becomes quickly too violent, even if it is only to eject defective objects.

It has already been proposed to associate with the pusher a guiding and retaining member, such as a star wheel carrying secondary cells. res locked by an elastic jaw, in which the pusher engages in passing the object to be determined, so that it is then extracted from the wheel at a point different from that where it normally emerges from the star (DE A 23 47563). However, on such a device, the action of the pusher remains extremely brutal at very high speed.

It has also been envisaged to combine the pusher with an elastic auxiliary wheel against which it applies the object to be evacuated for a sufficient time to allow the wheel to engage it on an auxiliary conveyor which deviates it towards a lateral corridor: the stroke of the pusher can be reduced, its action is made smoother and safer, but the gain in cadence is nevertheless limited.

This is why, as regards the optical control of bottles and flasks, there are incorporated sorting machines in which members such as a set of jaws or suction cups mounted on the star wheel opposite each cell and controlled by a distributor grips the necks to release the accepted bottles and the rejected bottles separately, at different times of the rotation cycle, so as to direct them towards two different conveyors. These machines are capable of operating at fairly high rates, but they are of fairly complex construction and relatively delicate to operate, and, designed for a determined angular pitch, they adapt quite poorly to changes in manufacturing corresponding to a significant change. shape or size of the articles, so that they are expensive, delicate to maintain and do not always have the desired flexibility of use.

We therefore also created separate ejection machines whose ejector device still accompanies the articles in their movement but is again placed on the side of the conveyor, downstream of the actual control station. In general, this device then consists of an endless band which carries pushers capable of gradually pushing back towards the auxiliary conveyor, when they are activated by a fault signal from the control station, the bottles or flasks that should be discarded.

These machines are, in principle, less complex to manufacture and allow operation at extremely high speeds. They are therefore of advantageous use on the bottling lines, but it should be noted that they require that the articles to be sorted are beforehand sufficiently spaced, since they pass over a considerable distance in front of the strip of pushers without that we can place guide along the conveyor to the corresponding location. There are therefore risks of shifting this or that article, all the more important since the apparatus is often wet or even greasy, and this is likely to disturb sorting. Such an incident may, in particular, occur in the event of a stop or engorgement of the downstream part of the chain if sufficient dead space is not provided at the exit of the device, or even in the event of a stop brutal. The machines in question are therefore not without drawbacks, in particular as regards their size on the chain.

Finally, it has therefore already been proposed to resort to an intermediate solution, in which an ejection member cooperates directly with a star-shaped distributing wheel, in particular that of a control station, by accompanying the articles to direct them at will in two different directions. Patent publication DE 29 36988 A1 describes in particular a vertical axis ejector wheel mounted opposite the star distributor wheel, synchronized with it and equipped, according to a pitch corresponding to its own, with a series of ejector fingers articulated on vertical axes placed at their upstream part. In order to eject the bottles, these fingers press against their surface to keep them in contact with the dispensing wheel. In fact, it turns out to be difficult to guide each bottle a sufficient distance to divert it from its normal path without the finger coming into contact with the next bottle or its angular movement being excessive, leading to variable slipping, factors of instability: the external face of the finger must have a concave shape, its end working alone, and each diameter of bottles requires a different ejector wheel. Finally, the structure of the fingers makes it difficult to tighten them enough so that the device lends itself to the ejection of small capacity bottles whose diameter does not exceed 50 to 60 mm.

The object of the invention is to provide a similar distributing wheel but with a more progressive action and a more compact structure. To this end, this wheel is equipped with ejector fingers articulated on axes placed at their downstream part and having a useful convex bearing which runs at rest along the periphery of the wheel. As a result, during ejection, the finger, after coming into contact with the bottle, deploys while rolling roughly without sliding along its surface and without imposing a shock on it. In addition, these fingers are not normally arranged in one, but in two peripheral rows superimposed in staggered rows or better still nested.

Preferably finally the outside diameter of the ejector wheel will be of the order of half or a third of the diameter of the circle defining the trajectory of the articles along the dispensing wheel.

The ejector wheel can itself be a star wheel meshing in a way on the distributing wheel by means of the containers but, at the high operating rates used, it is preferable, even essential, that it be synchronized independently on the latter via a mechanical transmission or an electronic synchronization device. In such a case, it is not necessary that the ejector wheel is a star wheel, it is even possible to admit between the two wheels a certain slip which makes it possible not necessarily to change the ejector wheel when one modifies, within a certain range, the pitch of the control machine with a view to a change of manufacture.

The ejector fingers are passive members permanently pushed outwards by a spring or similar elastic means but normally retained in the rest position, retracted, by a hooking member, so that their external reach runs along the periphery of the ejector wheel. The action of a jack, the operation of which is conventionally caused by an ejection signal sent by the control station when a defective article passes, releases a finger at the desired time to allow it to come to bear on the outer wall of this article and then gradually deploy, thus maintaining the article in position in its cell on the distributor wheel until it has crossed the normal exit zone towards the main conveyor and has engaged on the auxiliary elimination circuit. This jack is preferably placed at a fixed position and, likewise, the deployed fingers are then brought back into the locking position by an external resetting member arranged at a fixed position. It can again be a jack, but more simply a passive member comprising a reset roller or a cam so as to push the desired fingers back into the hooking position, one of these elements then advantageously disappearing under the action of a spring until the reset member is again urged by a deployed finger following the subsequent ejection of a new article. This element may in particular include a chin mechanism.

• - figure 1 : une vue de dessus schématique avec arraché d'une machine de contrôle équipée d'une roue éjectrice étoilée ;
• - figure 2 : une vue de détail, en coupe horizontale, de la roue éjectrice de la figure 1 ;
• - figure 3 : une coupe verticale de la roue éjectrice, selon la ligne III.III de la figure 2, montrant les deux rangées de doigts éjecteurs ;
• - figure 4 : à plus grande échelle, une section verticale correspondant à un détail de la figure 3 ;
• - figure 5 : de façon schématique, en plan, les phases de fonctionnement successives d'un doigt éjecteur ;
• - figure 6 : une vue de dessus d'une machine de contrôle à doigts imbriqués destinée à des bouteilles de petites dimensions ;
• - figure 7 : une vue latérale de cette machine.

A detailed description of two advantageous versions of the machine according to the invention is given below with reference to the figures who show :

• - Figure 1: a schematic top view with cutaway of a control machine equipped with a star ejector wheel;
• - Figure 2: a detail view, in horizontal section, of the ejector wheel of Figure 1;
• - Figure 3: a vertical section of the ejector wheel, along line III.III of Figure 2, showing the two rows of ejector fingers;
• - Figure 4: on a larger scale, a vertical section corresponding to a detail of Figure 3;
• - Figure 5: schematically, in plan, the successive operating phases of an ejector finger;
• - Figure 6: a top view of a nested finger control machine intended for small bottles;
• - Figure 7: a side view of this machine.

The machine shown as a whole in FIG. 1 is placed along a conveyor 1, at the outlet of a system of lateral guides 2. It mainly comprises a barrel carrying a star-shaped distributing wheel 3, having two superimposed plates whose teeth 4 grasp one by one, at the height of the barrel, the bottles 5 waiting on the conveyor, spacing them slightly apart, then present them in turn, on a circle D, in front of a control station shown diagrammatically at 6, while 'An endless band 7, circulating on pulleys 8 in front of the wheel 3, rotates them inside the cells of the latter. The diameter of the circle C of contact with the strip 7 will preferably be approximately constant from one manufacture to another and, for example, of the order of 750 mm. In the case shown in the figure, there are 24 of these cells, spaced 15 ° apart.

At the exit of the machine, the bottles are normally taken up by the conveyor 1, but a system of two guides 9a and 9b acting first on the level of the barrel of the bottles, the second on the level of the neck to obtain better stability, also draws a branch towards a branch 10. Opposite this branch and facing the distributing wheel is placed the throwing wheel 11. The periphery of this wheel carries a succession of throwing fingers 12, each of which is articulated on an axis 13 , and pushed outwards by a spring 14, but carries a lug 15, which allows a trigger 16 to retain it in the retracted position along a circle E defining the periphery of the ejector wheel, at a distance from the axis of the distributing wheel corresponding, apart from the clearances, to the radius of the contact circle C. If necessary, a pusher 17 will release one of the fingers opposite one of the bottles to cause the ejection of the latter by pushing it towards the bypass 10. In the figure two bottles are thus being ejected.

The device also includes a member 18 for resetting the ejector fingers, the operation of which will be described later.

The ejector wheel can have, for example, twelve ejector fingers distributed in two superimposed series of six fingers 12a, 12b spaced 60 °, themselves offset from each other by 30 °. Its center will then be placed at a distance from circle D equal, apart from play, to half of its radius, and its angular speed will be twice that of the distributor wheel.

The two wheels thus rotate without slipping, a finger appearing regularly in front of each cell; it is therefore possible to equip the ejector wheel with a star 19, in particular to facilitate evacuation on the downstream strand of the conveyor 1 if the latter makes with the direction of outlet of the bottles a more pronounced angle than that shown. Under these conditions, although the wheels mesh to a certain extent by means of the bottles which they trap, and because of the essential games it remains necessary in practice, to ensure its synchronization, to provide a separate drive of the ejector wheel , to allow very high operating rates and to avoid any incident in the event of an interruption in the supply of the machine.

On condition that the star 19 is omitted, it is however possible to admit a deliberate sliding between the deflections of the ejector wheel and the distributing wheel, so that the pitch of the latter could, for example, be reduced and the number of positions increased to thirty without the need to change the ejector wheel, provided, of course, that the movement of the latter is accelerated, so that the two wheels remain synchronized so that the presentation and the exhaust of each finger still occur at the desired times.

As best seen in Figure 2, the ejector fingers 12 have a length of the order of one and a half times the diameter of the bottles and a curved shape, which moreover gives them an outer reach 20 more convex than the periphery of the ejector wheel. By its action, the spring 14, wound around the axis 13 of each finger and trapped between the bearing 21 thereof and a pin 22, tends to push it outwards until its bearing 23 comes in stop on the pin 22. The hooking lug 15 of each of the fingers is formed of a bolt which is screwed onto the finger and that a lock nut 24 makes it possible to block in the suitable position.

The reset member 18 essentially comprises a cam 25, pushed back towards the ejector wheel 11 by a force limiting spring 26 and carrying one or two reset rollers 27.

On the other hand, it is generally useful, as the figures show, to equip the outlet branch with a semi-positive switching member 28 resiliently biased in the direction of the ejector wheel, in position 28 '. When it is at rest, this member positively directs the articles in the direction of the main outlet, corresponding to the downstream strand of the conveyor 1 ensuring them continuous guidance, but, if the force which it exerts, taking into account the arms respective levers, is less powerful than that of the ejector fingers 12, when one of these fingers is deployed in front of a bottle to be ejected, it maintains it in its cell on the dispensing wheel and this bottle repels the switch 28, the gradually moving away to engage towards the diversion 10.

The switch 28 advantageously consists of two or more independent blades 28a, 28b of different lengths, hinged here on the same axis 29 located upstream and capable of returning to rest independently of each other under the action of separate springs 30a, 30b as soon as the bottle being ejected has passed them, so as to be ready to guide the next bottle towards the main conveyor, unless it is necessary to eject it in turn .

As shown in FIG. 3, the ejector wheel comprises a hub 31 carried by a shaft 32 and integral with a drive pinion 33 synchronized by a suitable transmission, not shown, with the device for driving the barrel of the distributor wheel . The hub 31 carries a web 34 and also receives two flanges 35a and 35b. On these three elements are mounted on the one hand the axes, or 13a and 13b, which respectively receive the pushers or 12a and 12b, on the other hand the pins 22a, 22b.

It can be seen more clearly in FIG. 4 that the head of the lug 15 has a conical front part 151 and forms in its part posterior tie a shoulder 152.

On either side of the hub 31 are also mounted two series of triggers, namely 16a, 16b, resiliently biased upwards so as to retain the ejector fingers 12a, 12b respectively. In the example shown, these triggers consist of a plate 161 carrying upward, at its end, a tenon 162 and mounted on a spring leaf 163. At rest, the tenon 162 comes to hang behind the shoulder 152 formed by the rear face of the head of the lug 15, and thus retains the erased finger along the periphery of the ejector wheel.

Two sets of detent plungers, 17a and 17b, are alternately supported by the triggers 16a and 16b, which they are capable of pushing down, thereby releasing the lug 15 and consequently the corresponding ejector finger 12.

It is a jack 36, fixed on the shaft 32 of the ejector wheel, which causes the possible lowering of the pushers. When its rod 37, carrying a roller 38 is lowered, the latter comes to press while rolling on the head of that of the pushers 17 which is present at this time; he therefore pushes it in, which releases the ejector finger, after which the rod of the actuator rises, releasing the trigger which in turn repels the pusher. The usually very high operating rate of the machine leads to the use of a double action pneumatic cylinder.

The action of the ejector finger appears in FIG. 5: in the event of the passage of a defective bottle, the fault signal emitted by the receiver 6 triggers the operation of the jack 36 with a suitable delay and thus releases the ejector finger which appeared in front of the bottle in question. The convex outer surface 20 of the latter presses against the barrel of the bottle, in the manner indicated in phantom, in 1, in the figure then, gradually unfolding in the manner of an elastic cam, maintains the bottle in its cell, as already seen in Figure 1, pushing the two blades of the switch 28. The finger 12 finally escapes to come into abutment on the pin 22 (position 2) while the bottle, - already engaged by him on the bypass, it is now retained there at the neck by the guide 9b and also comes into contact, at the barrel, with the guide 9a.

The deployed finger finally arrives, as seen in 3 in the figure, in contact with the rearming member 18, the cam 25 of which forces it to gradually fold back; the ramp formed by the conical bearing 151 of the head of the lug 15 finally comes into contact with the lug 161 and begins to push the trigger 16 down. The finger then reaches the roller 27; the latter pushes it further inward (position 4) so that the ramp 151 of the lug 15 passes beyond the lug 162 which then rises behind the shoulder 152, again locking the finger 12 which then escapes to return to the position of complete rest, that is to say a slight projection on the position of the roller 27.

The machine of FIG. 6 has a structure very similar to that of the previous machine and the corresponding references have been kept for the homologous members. However, it is particularly intended for bottles of small dimensions circulating at very high rates; this is why the distributing wheel 3, the external diameter of which is unchanged, is equipped with thirty-six stations. Half the size of the ejector wheel 11, which is mechanically synchronized, carries eighteen ejector fingers and rotates at double angular speed. The above data results in a significantly more compact ejector wheel than in previous versions. On the other hand, the design of the machine is designed so that all the fingers can act under identical conditions, the active part 20 ′ of their convex surfaces 20a, 20b being placed at the same height, in this case located opposite the area of larger diameter of the bottles so as to form a single band; to this end, the hinge pins 13a, 13b of the fingers and all of their attachment and ejection mechanisms are alternately offset on either side of this strip, which makes it possible to accommodate them more easily. Thus, as shown in Figure 7, the hub 31 carries two separate webs 34a, 34b; the axes 13a of the fingers 12a, their springs 14a as well as the pins 22a are carried by the cheeks 34a, 35a, the corresponding members of the fingers 12b by the cheeks 34b, 35b. The fingers have the shape of L-shaped paddles, two to two symmetrical, and the two webs 34a, 34b are cut alternately at 39a and 39b to let their ends pass, whose outer surfaces 20a, 20b are thus aligned in one ejection strip 40 between the two adjacent cheeks. The attachment members, pins 15 (a and b) and triggers 16 (a and b) similar to those of the previous versions, are visible from place to place in FIG. 7.

There is still a double switch flap 28a, 28b but the structure of the reset member 18 is somewhat different; the cam 25 is indeed carrying two studs 41a, 41b returned to rest by respective springs 42a, 42b.

When a finger 12 deployed but already folded towards the wheel 11 by the cam 25 meets the corresponding chin 41, it tilts it downstream, thus advancing towards the wheel; the chin therefore pushes the finger inward again, causing it to be re-attached but, once released by it, it returns to rest, which then prevents it from constantly coming into contact, during the rotation of the ejector wheel, with each of the fingers 12 remained in the locked position. We could also in the same way, for example use an eccentric cam.

As an indication, it is possible to provide the characteristics indicated in the following table, where it will be noted that column 4 corresponds to the joint use of the distributing wheel of column 3 and of an ejector wheel according to column 2, devoid of drive star 19, the speed of which has been increased to introduce a slip of the order of 7% which allows the respective stations to remain face to face during operation.

Claims (7)

1. Device for sorting articles on a chain of horizontal conveyors, comprising an ejection assembly consisting of an ejector wheel (11) with a vertical axis mounted opposite a star-shaped distributing wheel (3), synchronized with it and equipped, according to a step corresponding to its own, with a series of ejector fingers (12) articulated on vertical axes (13), which accompany these articles in their movement and are thus capable of pushing them out of their normal path , characterized in that these fingers (12) have a useful convex bearing length at rest along the periphery of the wheel and that their axes are placed at their downstream part. 2. Device according to claim 1, the fingers of which are mounted nested on axes which are offset relative to their useful external bearing surfaces, characterized in that these fingers (12a, 12b) are arranged symmetrically in two offset rows, said axes (13a, 13b) located alternately on either side of the ejection line (40) formed by these useful bearing surfaces (20 '). 3. Device according to claim 1, characterized in that the fingers (12a, 12b) are arranged in two superimposed peripheral rows, offset between them by half a step. 4. Device according to one of claims 1 to 3, characterized in that the ejector fingers are passive members elastically pushed outwards but normally retained in the retracted position by a hooking member (15). 5. Device according to claim 4, whose deployed fingers are returned to the hooking position by a passive external reset member with fixed station (18), characterized in that one of the elements (41) which then come into play pivots when the finger to be reset meets, then disappears under the action of a spring (42). 6. Device according to claim 5, characterized in that the resetting member comprises a cam (25) associated with a chin mechanism (41,42) urged by a deployed finger following the ejection of an article . 7. Device according to one of the preceding claims, characterized in that the ejection assembly is opposite to a passive switch (28) that the fingers repel through the articles when they are deployed.

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