SELECTION SYSTEM FOR THE ENTRY OF A CONVEYOR BELT OF TRANSPORTED OBJECTS

Description

Field of invention

[0001] The invention relates to an installation for selecting objects moving along a transfer line consisting of an endless belt between an object inlet and an object outlet, accepted, with rejection of non-compliant objects in the ejection zone.

[0002] The objects moving along the transfer line are objects coming, for example, from a manufacturing and packaging phase to be checked and used for a new operation or to be packaged.

[0003] These objects can have very different shapes corresponding to their packaging such as a container, a tray, a bottle, a flask and the selection criterion is a criterion which the object passing through the installation must meet, that is to say for example the filling level of a flask or a bottle, the weight of the packaged object, the presence of a visible element on the object such as a label or a closing element such as a cap; the criterion can also be a quality of transparency corresponding to good or poor cleaning of a still empty container such as a bottle entering a filling station. State of the art

[0004] There are various object selection installations for checking objects on a conveyor line and removing non-compliant objects. These known installations use either mechanical or pneumatic means to remove the non-compliant object. The mechanical means generally consist of a pusher that acts transversely on the object moving in the removal zone. This pusher is controlled by a hydraulic or pneumatic means such as a cylinder, or an electromechanical means such as an electromagnetic cylinder.

[0005] For small or light objects, there are also ejectors consisting of a blower which directs a jet of air to evacuate the object which is on the scroll line into the evacuation station.

[0006] Air jet ejectors are limited to very specific objects or products that are light enough to be ejected in this manner.

[0007] The most common ejectors are mechanical ejectors controlled by a pneumatic, hydraulic, or electromagnetic actuator. These ejectors must operate very quickly so as not to hinder or disturb the next product in the flow line. This requires a relatively abrupt action to be effective and fast.

[0008] These evacuation devices are generally relatively bulky and do not spare the evacuated objects; in the case of fragile objects such as bottles, they risk breaking the bottles, which is not always appropriate because these containers, on the one hand, could be recovered and on the other hand, their breakage creates pieces which can clutter the scroll line, depending on the place where the object is encountered by the ejector and be a source of operational incidents. "It is known according to document DE 3241100 to divert packages (P) from a conveyor by a switching installation towards a direction perpendicular to the direction of the conveyor. This installation consists of a guide plate (70) and a vertical guide roller (60) as well as a horizontal drive roller (50) which takes charge of the package (P1) to lead it onto the conveyor of the diversion.The deflection movement of the switch is initiated by the contact of a roller (35) carried by a deflecting member (30) in the form of an arm which rests and rolls on the side of the package (P1) to be deflected, to direct it into the switch members (70, 60, 50a). Such an installation can only be applied to rectangular-shaped packages, offering a contact surface with the roller (35) allowing the change of direction of the package by the accompaniment provided by the deflecting member (30) and its roller (35). Such an installation does not allow an impulse to be applied to eject an object of any section transported by a conveyor. Purpose of the invention

[0009] The aim of the present invention is to develop an installation for selecting objects moving along a transfer line, which is efficient, rapid and allows non-compliant objects to be removed in a controlled manner without disrupting the movement of objects upstream and downstream and which can adapt to a wide variety of shapes and dimensions of the objects being checked. Description and advantages of the invention

[0010] To this end, the present invention relates to an installation for selecting objects moving along a transfer line consisting of an endless belt between an object inlet and an object outlet, accepted, with rejection of non-compliant objects in the evacuation zone comprising: an ejector device with pivoting arms whose trajectory overlaps the trajectory of the objects, installation characterized in that the ejector device is formed: of two pivoting, driven arms, whose rotation trajectory overlaps the line of movement of the objects in the evacuation zone, the two arms being diametrically opposed, each ending in a curved bearing surface;the direction of rotation of the arm in the evacuation zone corresponds to the direction of movement of the objects with a speed component in this direction at least equal to the movement speed and a transverse component to evacuate the object, to quickly and gently accompany the object to be evacuated without disturbing the object upstream by the thrust of the object to be evacuated nor the object downstream by its encounter with the pivoting arm, the driven arm receiving a control signal from the object to be ejected to impact this object which arrives in the evacuation zone and evacuate it from the movement line.;

[0011] This balanced shape of the ejector device allows very efficient operation since the arm only has to make a half-turn for its active stroke between the encounter with the object to be evacuated and its arrival in the rest position; this movement results in the alternating movement of the other arm which passes from the rest position to the waiting position, close to the ejection zone so that it can in turn evacuate very quickly a new object which is also defective and in particular the object which directly follows downstream the object which has just been evacuated.

[0012] This balanced ejection device, operating by rotational movements, has very little inertia and above all it saves in some way the time of returning to the rest position since at the end of the evacuation phase, the diametrically opposite arm is already in the waiting position, ready for a new evacuation movement.

[0013] According to another characteristic, each arm is composed of an ejection member fixed to a support carried by the axis, the ejection member being fixed by one end to the support, the other end having a curved bearing surface.

[0014] This embodiment is particularly effective because it allows, on the one hand, to produce the ejection member in a plastic material, possibly without friction such as PTFE so as to facilitate contact with the object to be evacuated and to allow it to be accompanied in the evacuation zone.

[0015] According to another advantageous characteristic, the ejection member is a plastic part, in particular PTFE. Drawings

[0016] The present invention will be described hereinafter in more detail with the aid of an embodiment of an object selection installation shown in the accompanying drawings in which: there figure 1is a schematic top view of the selection facility, the figure 2 is a schematic top view of an embodiment of the selection installation at the rotating arm, the figure 3 , in its parts 3A, 3B, shows a detail in top view of the evacuation device, the Figure 3A shows the application of the device to three objects of different dimensions represented by circles of different sizes, the Figure 3B schematically shows the ejection movement by the contact of the arm with the object. Description of an embodiment of the invention

[0017] There figure 1 shows a selection installation 100 of objects Ni scrolling on a scroll line LD between an input 11 through which objects Ni arrive and an output 12 of objects selected because they conform to a certain criterion. Non-conforming objects N'i are ejected from the scroll line LD into the receptacle 13.

[0018] The objects represented by circles Ni are placed freely on a conveyor belt 1 driven in direction D at speed V, preferably constant in steady state, outside the start-up and slow-down phases.

[0019] Ni objects are in principle objects of a series of the same shape, for example objects of circular cylindrical shape, of revolution shape or parallelepiped or cubic such as bottles, flasks, containers, boxes, trays, transparent or opaque.

[0020] Ni objects must meet a conformity criterion which can be the shape or the content of the object if it is a container, a bottle, a flask. The conformity criterion observed on the LD scroll line is the shape (silhouette), the dimensions, the weight, the correct filling of a container or a bottle, the correct transparency of a container before its filling or the traces that it can have and which require its evacuation or the presence of accessories such as labels, a cap, a capsule as well as numerous criteria of appearance, dimensions, colors, transparency which can be the criterion or criteria to be checked to eject the object which does not meet.

[0021] Ni objects are distributed, preferably but not necessarily, at regular intervals. For the purposes of description, the figure 1highlights a group of three objects Ni-1, Ni, Ni+1 on a 2D interval between the center of the first and third objects Ni-1, Ni+1 of this triplet taken in the direction D of the scrolling. The two extreme objects of this triplet are on either side of a detected non-compliant object (this object is highlighted by cross-hatching) and for this reason has a reference with (') N'i. The object N'i must be taken out of the scrolling line LD without the two other objects Ni-1, Ni+1 which frame it being taken out.

[0022] The installation 100 comprises a sensor 2 for detecting objects Ni, an evacuation device 3 for evacuating non-compliant objects N'i and a control unit 4 for managing the operation of the installation.

[0023] The sensor 2 installed on the LD scroll line above or astride the conveyor belt 1 comprises: a detector 21 for detecting the Ni object arriving in its reference position (reference line 22) relative to the sensor, and an analyzer 25 for analyzing the characteristic of the Ni object and allowing its conformity control.

[0024] The analyzer 25 can also be combined with an upstream analyzer which will have marked the object with a marker indicating if it is not compliant. The analyzer 25 of the sensor is then limited to detecting this marking of the object N'i as it passes the sensor 2.

[0025] The analyzer 25 checks one or more conformity criteria of the object such as dimensional, shape, appearance, color, transparency parameters, analyzed as the object Ni scrolls.

[0026] Sensor 2 transmits for each Ni object an identity signal SID-Ni and a quality signal SQ-Ni.

[0027] The SID-Ni identity signal simply identifies the object by the time it passes from the reference position (line 22) into the detector 21.

[0028] The SQ-Ni signal indicates whether or not the object meets the selection criterion.

[0029] According to the design of the analyzer 25, it provides a raw signal not compared to the selection criterion or already compared to it and which is then a binary type signal.

[0030] Sensor 2 detecting the scrolling objects Ni makes it possible to know the interval between two objects (Ni, Ni+1), (Ni-1, Ni) and thus their scrolling speed if this is different from the constant speed V.

[0031] The control unit 4 manages the operation of the selection installation 100 from the signals supplied by the sensor 2 to generate the control signals SCN'i of the evacuation device 3 to control the evacuation of non-compliant objects N'i.

[0032] The evacuation device 3, installed on the scroll line LD of the objects Ni, consists of an arm 31 carried by an axis 32; it describes a circular trajectory TC which overlaps the scroll line LD and the conveyor belt 1 forming an evacuation zone 35.

[0033] The arm 31 is driven from a waiting position next to the scroll line LD and the conveyor belt 1 to allow the conforming objects Ni to pass freely. The arm 31 performs a semi-circular sweeping movement to pass into the discharge zone 35 and push the non-conforming object N'i to evacuate it from the scroll line LD without impacting either the upstream object Ni-1 or the downstream object Ni+1. By convention, these references of the objects in the discharge device 3 are those of the three objects which were previously in the region of the sensor 2.

[0034] The direction of rotation of the arm 31 in the evacuation zone 35 corresponds to the direction D of the movement of the objects Ni with a speed component in this direction which is at least equal to that of the movement speed and a transverse component to evacuate the object N'i. The movement of the pivoting arm 31 is controlled by the signal SCN'i of the control unit 4. This signal controls the movement of the arm 31 at the time of arrival of the object N'i in the evacuation zone 35, preferably as soon as possible, so as to reduce the necessary length of the arm 31 and its incursion in depth in the movement line LD to allow the evacuation of an object N'i between two objects Ni-1, Ni+1 close together. This allows a dense distribution of the objects Ni on the movement line LD.

[0035] The control signal SCN'i associated with the non-compliant object N'i takes into account the distance DP that the object N'i must travel between its position detected 22 by the sensor 2 and the evacuation zone 35 in the evacuation device 3, at the detected movement speed.

[0036] According to the figure 2 , the arm 31 is preferably doubled by another arm 31', diametrically opposite, balancing the pivoting assembly and making it possible to reduce the evacuation stroke to a half-turn between a waiting position facing the scroll line LD and a rest position after an ejection stroke.

[0037] By convention, in its waiting position, the arm bears the reference 31 and in its rest position, the reference 31'.

[0038] There figure 2 being a top view, the conveyor belt 1 is generally horizontal and the axis 32 of the arm 31 is a vertical axis. The controlled motor driving the axis is not shown.

[0039] The pair of rotating arms 31, 31' is formed of a support 33 carried by the axis 32 and to which are fixed two ejection members 34 of generally trapezoidal shape having a fixing end 341 and an active end with a curved bearing surface 342 for pushing the object N'i.

[0040] In order not to complicate the description of the pair of arms, the references 31, 31' have been used, as indicated above, to designate the two arms which are of identical shape. Reference 31 is attached to the arm in its waiting position and in its movement of evacuating the object N'i. Reference 31' is used for the arm in the rest position.

[0041] The arms alternate between the two positions.

[0042] The ejection members 34 are preferably elements made of plastic with a low coefficient of friction such as PTFE, also having advantageous damping characteristics for contact with the object N'i. These ejection members 34 are removably fixed to the support 33 to allow their replacement.

[0043] The curved section of the support surface 342 adapts to objects Ni, with a rounded or circular outline and of different dimensions, which can pass over the scroll line LD. This rounded shape is also advantageous if the object has a polygonal section, for example rectangular or square. The meeting of the support surface 342 with the outline of the object N'i must be as close as possible to the "vertex" of the object N'i. According to the present description, by convention, the vertex S of an object is the region of the object furthest from the scroll line LD taken as a reference and on the side of the evacuation device 3. In the case of an object with a circular or elliptical section, the geometric vertex S is the intersection of the perpendicular to the scroll line LD passing through the center of the object with its circular (or rounded) outline.In the case of a polygonal object, we will proceed by analogy using the circumscribed circle to define the vertex region.

[0044] Thus and very schematically, the direction of the ejection impulse communicated by the support surface 342 to the object N'i always remains well oriented in the evacuation zone 35 towards the receptacle 13, which prevents the object N'i to be ejected from jostling the object Ni-1 which is upstream on the scrolling line LD.

[0045] The curvature of the bearing surface 342 not only makes it possible to better adapt to different dimensions of the objects (without having to change the arm or the ejection member) but also to better accompany the movement of the object N'i in the evacuation zone 35 towards the receptacle 13 over the short contact path between the arm 31 / bearing surface 342 and the object N'i. This is all the more important since, according to the invention, the arm 31 with its bearing surface 342 must be short to allow the objects Ni to be brought together on the running line LD.

[0046] The impact region of the support surface 342 with the object N'i is fixed by the control signal SCN'i supplied by the control unit 4. This signal takes into account the shape of the object N'i, the distance DP to be covered to arrive at the evacuation zone 35 and the speed (reaction time) of the arm 31.

[0047] On the last part of the semi-circular trajectory, arm 31 is no longer in contact with object N'i and circulates in the interval between objects Ni-1, Ni+1, preceding object Ni+1 thanks to its speed component in direction D which is greater than that of object Ni+1.

[0048] There Figure 3A shows the application of the device to three objects of different dimensions represented by circles of different sizes, C1, C2, C3 showing that the curved support surface 342 impacts the object N'i for its evacuation without risking pushing it against the object Ni-1 directly upstream. Thanks to its curvature, the support surface 342 always meets the contour of the object whatever its diameter C1-C3, ranging from a small diameter C1 to a large diameter C3, always near the "top" and which applies to it a thrust component strongly oriented in the transverse direction.

[0049] There Figure 3Bschematically shows the ejection movement by the contact of the arm 31 with the object N'i, highlighting the transverse trajectory of the object N'i towards the receptacle 13.

[0050] Very schematically, at the instant of contact of the support surface 342 with the object N'i, the direction of the thrust P is more strongly inclined relative to the running line LD constituting a reference line than the tangency line TG common to the contours of the objects Ni-1, N'i so that the object N'i does not risk being pushed against the object Ni-1 upstream. This drawing assumes that the running of the strip 1 is stopped at this moment of contact. In reality, the strip 1 is running (direction D) and the contact between the object N'i and the support surface 342 approaches the "top" S of the object and the direction of thrust P becomes more and more perpendicular to the running line LD so that the trajectory TR of the object N'i curves even more. NOMENCLATURE

[0051] 100Object selection facility 1Conveyor belt 11Inlet 12Outlet 13Receptacle 2Sensor 21Detector 22Detection line 25Analyzer 3Discharge device 31,31'Swivel arm / other arm 32Axis 33Support 34Ejector 341Attachment end 342Support surface 35Discharge area 4Control unit LD Scrolling line D Scrolling direction V Scrolling speed 2 DEpitch DP Distance to travel TC Circular path Ni Object N'i Object to be evacuated SID-Ni Identity signal SQ-Ni Quality signal SCN'i Control signal TR Trajectory of the evacuated object

Claims

1. Installation for selecting objects moving on a transfer line which is constituted by a continuous belt (1) between an inlet (11) for objects and an outlet (12) for objects which are accepted with non-compliant objects (N'i) being rejected in the discharge zone (35) comprising: - an ejection device (3) with pivoting arms, the trajectory of which overlaps the trajectory of the objects, which installation is characterised in that - the ejection device (3) is formed: - by two driven pivoting arms (31), the rotational trajectory of which overlaps the movement line (LD) of the objects (Ni) in the discharge zone (35), the two arms being diametrically opposed, each one being terminated by a curved abutment surface (342), - the rotation direction of the arm (31) in the discharge zone (35) corresponds to the movement direction of the objects (Ni) with a speed component in this direction at least equal to the movement speed and a transverse component for discharging the object, in order to accompany rapidly and carefully the object to be discharged without disturbing the object upstream by pushing the object to be discharged, nor the object downstream as a result of it being touched by the pivoting arm, - the driven arm (31) receiving a control signal (SCN'i) of the object (N'i) to be ejected in order to impact this object which arrives in the discharge zone (35) and to discharge it from the movement line (LD).

2. Installation according to claim 1, characterised in that the transport belt (1) is horizontal and the axle (32) of the arm (31) is a vertical axis.

3. Installation according to claim 1 and claim 2, characterised in that the arm (31) is driven from a waiting position beside the movement line (LD) and the transport belt (1) in order to allow compliant objects (Ni) to pass freely, the arm (31) carrying out a scanning movement in a semi-circle in order to pass into the discharge zone (35) and to push the non-compliant object (N'i) in order to discharge it from the movement line (LD) without impacting either the upstream object (Ni-1) or the downstream object (Ni+1).

4. Installation according to claim 1, characterised in that the ejection device (3) comprises two arms (31, 31') which are diametrically opposed and which are carried by an axle (32) and which are each terminated by a curved abutment surface (342) in order to come into contact with the object (N'i) to be discharged.

5. Installation according to claims 1 to 4, characterised in that each arm (31, 31') is composed of an ejection member (34) which is fixed by one end (341) to a support (33) which is carried by the axle (32), the other end having the curved abutment surface (342).

6. Installation according to claim 5, characterised in that the ejection member (34) is a component made of plastics material, in particular of PTFE.

7. Installation according to claim 1, characterised in that it comprises: - a sensor (2) * which is installed on the movement line (LD) of the objects (Ni), * and which generates an identity signal (SID-Ni) of the object (NI) at the time at which the object (Ni) moves into the detection zone (22) of the sensor (2), and * a quality signal (SQ-Ni) of the object (Ni) resulting from the analysis of the object (Ni), - a control unit (4) * which receives the identity signal (SID-Ni) and quality signal (SQ-Ni) of each object (Ni), - generating a control signal (SCN'i) if the quality signal (SQ-Ni) of the object (Ni) is not compliant with the criterion imposed, ** this control signal (SCN'i) taking into account the travel speed of the object as far as the discharge zone (35).