EP0519375B1 - Loading apparatus for sorting machine for flat objects such as letters - Google Patents

Description

The present invention relates to a device for loading a machine for sorting flat objects comprising at least one antenna for inputting objects one by one and a number of buckets where the objects are loaded vertically to be transported and unloaded in outlet containers, the loading device for conveying objects one by one from the input antenna to a vertical bucket and comprising a conveyor substantially perpendicular to the trajectory of the buckets and associated with a vertical transfer device towards the down objects in a bucket.

• d'un carrousel de tri comportant un certain nombre de godets véhiculés sur des rails de guidage,
• une ou plusieurs antennes d'entrée où les objets sont alimentés, manuellement ou automatiquement, un à un après saisie du code postal, pour être chargés dans les godets grâce à un dispositif de chargement,
• un certain nombre de sorties où les plis de même destination sont déchargés et empilés dans un même bac ou équivalent.

Such a sorting machine for flat objects, in particular postal objects, consists of:

• a sorting carousel comprising a certain number of buckets carried on guide rails,
• one or more input antennas where the objects are fed, manually or automatically, one by one after entering the postal code, to be loaded into the buckets thanks to a loading device,
• a number of outlets where items of the same destination are unloaded and stacked in the same bin or equivalent.

Such a sorting machine is described in French patent FR-2 454 338 where the loading of the objects is ensured by horizontal conveyor belts alternating with rollers which can be raised by means of a jack to direct the objects in the direction of the trajectory. buckets and insert them in a corridor which can pivot thanks to a motor between a substantially horizontal position which allows it to receive the object to be loaded and a substantially vertical position which enables this object to be unloaded in the corresponding bucket. This corridor has an outlet chute closed by a pivoting gate controlled by a lever actuated by an actuating device. Loading devices for a bridge sorting machine still known from documents FR-A-1,565,292 and CH-A-311,922

The invention provides a more efficient loading device, which allows a particularly high rate while being simple, compact and suitable for a wide spectrum of mail.

This loading device is in particular intended to equip a sorting machine comprising a carousel, supplied by several input antennas, serving up to 180 sorting directions and capable of a minimum throughput of six objects per second. To limit the speed of the carousel, objects are transported in buckets in a direction normal to their surface. The pitch between buckets of the carousel being approximately 90 mm, the flow of objects is obtained with a minimum transfer speed of 0.54 m / s.

The maximum number of input antennas is such that it remains compatible with the minimum flow of six objects per second. Taking into account the practical flows of which three types of envisaged input antennas are capable (manual presentation and coding: approximately 0.7 object / second, automatic presentation and manual coding: approximately 1.1 object / second, automatic presentation and optical reading: approximately 1.8 objects / second), the antennas can be combined in number and type such that their cumulative flow does not exceed the flow of the conveyor.

Said sorting machine allows the processing of a particularly wide mail spectrum. As an indication, the surface L x h can vary between 145 mm x 250 mm and 225 mm x 353 mm, the thickness between 0.5 and 20 mm and the mass between 10 g and 500 g. In addition, the loading device must be suitable for any condition of this mail, whatever its rigidity or flexibility, regardless of its packaging (rigid cardboard or flexible plastic).

• le module convoyeur comporte au moins deux barrières d'arrêt espacées d'une distance supérieure à la longueur maximale des objets,
• un module accélérateur est disposé entre le module convoyeur et le dispositif de transfert vertical et comprend, en aval, une barrière d'arrêt,
• le dispositif d'éjection vertical est constitué d'un module injecteur,

   ces modules étant pourvus d'organes d'entraînement positif actionnés en continu et les barrières d'arrêt étant escamotables et gérant le déplacement des objets grâce à des détecteurs disposés sur la trajectoire des objets.To do this, according to the present invention,

• the conveyor module comprises at least two stop barriers spaced by a distance greater than the maximum length of the objects,
• an accelerator module is disposed between the conveyor module and the vertical transfer device and comprises, downstream, a stop barrier,
• the vertical ejection device consists of an injector module,

these modules being provided with positive drive members actuated continuously and the stop barriers being retractable and managing the movement of objects thanks to detectors placed in the path of objects.

Preferably, the three modules are aligned and include a support surface for the objects inclined relative to the vertical plane.

According to a preferred embodiment, each stop barrier consists of a retractable finger serving as a stop. This finger crosses the bearing surface in the active position and it is secured to a lever pivoting about a horizontal axis. It is activated by an electromagnet.

Preferably, the conveyor and accelerator modules have a support surface perpendicular to the support surface.

According to a preferred embodiment, the support surface and the support surface of the conveyor module are equipped with continuously actuated conveyor belts.

In addition, the conveyor module is equipped, near each stop barrier, with a pressure roller, free to rotate, mounted at the end of a lever pivoting about an axis perpendicular to the support surface and spring loaded.

According to a preferred embodiment, the accelerator module comprises a transfer means and an acceleration means pivoting from a rest position to an active position where the object is sandwiched between these two means which are actuated in continuous rotation.

Preferably, the transfer means consists of at least one pair of pulleys mounted respectively on two shafts parallel to the bearing surface, at least one endless belt being mounted on these pulleys.

According to a preferred embodiment, the acceleration means consists of at least one endless belt stretched over at least one pair of pulleys mounted on two integral shafts, one of which is pivotable and actuated by an electromagnet.

• le module injecteur comprend un moyen de transfert vers le bas tangentiel à la surface d'appui, un moyen de pression pivotant autour d'un axe horizontal et un volet d'obturation escamotable formant surface de support perpendiculaire à la surface d'appui.
• le moyen de transfert vers le bas est constitué d'un rouleau rotatif autour d'un axe horizontal actionné en continu.
• le moyen de pression est contitué d'au moins deux galets libres en rotation selon un axe horizontal montés sur un cadre pivotant autour d'un axe horizontal et actionné par un électro-aimant.

Preferably:

• the injector module comprises a means of transfer downward tangential to the support surface, a pressure means pivoting about a horizontal axis and a retractable shutter forming a support surface perpendicular to the support surface.
• the downward transfer means consists of a roller rotatable around a continuously actuated horizontal axis.
• the pressure means is made up of at least two free rollers in rotation about a horizontal axis mounted on a frame pivoting about a horizontal axis and actuated by an electromagnet.

• les barrières d'arrêt du module convoyeur sont normalement ouvertes et sont fermées lorsqu'un pli arrive, si un pli est présent en butée sur la barrière d'arrêt suivante,
• la barrière d'arrêt du module accélérateur est normalement fermée et est ouverte après l'arrivée d'un pli, si aucun pli n'est détecté dans le module injecteur,

   D'autres fonctions et avantages des caractéristiques de l'invention apparaîtront à la lecture de la description suivante d'un mode de réalisation préféré.The invention also relates to a method of implementing the charging device according to which photoelectric sensors are arranged on the trajectory of the objects in order to manage the displacement of these and:

• the stop barriers of the conveyor module are normally open and are closed when a fold arrives, if a fold is present in abutment on the next stop barrier,
• the stop barrier of the accelerator module is normally closed and is opened after the arrival of a fold, if no fold is detected in the injector module,

Other functions and advantages of the characteristics of the invention will appear on reading the following description of a preferred embodiment.

The invention is set out below in more detail with the aid of figures representing only a preferred embodiment.

Figure 1 is a front view of the device.

Figure 2 is a front view of the conveyor module.

FIG. 3 is a sectional view along III - III of FIG. 2.

FIG. 4 is a sectional view along IV - IV of FIG. 2.

Figure 5 is a front view of the accelerator module.

Figure 6 is a sectional view along line VI - VI of Figure .7.

Figure 7 is a top view of the accelerator module.

Figure 8 is a front view of the injector module.

Figure 9 is a top view of the injector module.

Figure 10 is a side view of the injector module.

Figure 11 is a schematic top view of the device installed in a sorting machine.

As can be seen in FIG. 1, the loading device is made up of a conveyor module 100, an accelerator module 200 and an injector module 300 aligned.

All of these modules have a bearing surface 2 inclined with respect to a vertical plane (approximately 20 °) and the conveyor and accelerator modules have a support surface 3 perpendicular to the support surface 2. The objects are therefore arranged with their longest edge placed on the surface support 3 and their surface supported on the support surface 2.

The conveyor module 100 is equipped with three barrier barriers BA1, BA2 and BA3, while the accelerator module is equipped with a barrier BA4. The conveyor module therefore allows buffer storage of three objects 1. Near each stop barrier, the conveyor module 100 is provided with a pressure roller 110.

The conveyor module 100 is provided with two conveyor belts 102, 103 on its support surface 2 and a conveyor belt 104 on its support surface 3. Upstream of each barrier and between the conveyor belts 102, 103 flexible blades 105 are arranged which reduce the contact force of the fold on the strips 102, 103 when the barriers BA1, BA2, BA3 are closed.

The accelerator module is provided with a transfer means and an acceleration means 210, 220.

The injector module is provided with a downward transfer means (not visible), a pressure means 320 and a retractable shutter 330.

The positive drive members that are the strips 102, 103, 104, the transfer means 210 and acceleration 220 and the transfer means downwards from the injector module are actuated continuously. The movement of the objects 1 is managed by the stop barriers BA1 to BA4 thanks to detectors placed on the trajectory of the objects 1 as will be seen more precisely below.

The conveyor module will now be described more precisely with reference to FIGS. 2, 3 and 4.

Each pressure roller 110 is free to rotate about an axis 111 perpendicular to the support surface 3 and mounted on an arm 112 pivoting around an axis 113 secured to a fixed support piece 114. Springs 115 urge the lever so that the roller 110 is pressing against the bearing surface 2. The support piece 114 also carries a photoelectric emitting cell C1 not shown on FIG. 4 associated with a receiver 155 fixed on the support surface 2.

The front edge of the conveyor belt 104 is covered with a stop band 116.

The BA1 stop barrier is particularly visible in Figure 4. The BA2 and BA3 barriers are identical.

The BA1 stop barrier consists of an abutment finger 120 fixed on a lever 121 articulated in pivoting around a horizontal axis 122. The lever 121 is actuated by an electromagnet 123 with single effect, its return being carried out by a spring 124. The stopping barrier BA1 is shown in the retracted position. In the active position, the finger 120 comes to form a stop crossing the orifice 125 and pushes the pressure roller 110 by pivoting the arm 112 around the axis 113.

The accelerator module 200 is described below with reference to FIGS. 5, 6 and 7.

Figure 5 is a front view where the bearing and support surfaces 2 and 3 have been removed for better visibility.

This module 200 comprises a means of tangential transfer to the support surface 2 and an acceleration means supported by the support surface 3.

The transfer means consists of two endless belts 201 and 202, tensioned on pulleys 203, 204, 205 and 206, mounted in pairs on two axes 207, 208 parallel to the support surface 2 and perpendicular to the surface of support 3. The axis 208 is driven in continuous rotation by a motor 209 by means of a belt 210. The belts 201 and 202 come to tangent the bearing surface 2 by slots 211, 212.

The accelerating means also consists of two endless belts 213, 214 tensioned on pulleys 215, 216, 217 and 218 mounted in pairs on two axes 219, 230 parallel to the support surface 2 and perpendicular to the surface of support 3. The axis 230 is driven in continuous rotation by the motor 209 by means of the belt 210.

Note that this same motor 209 can also drive the conveyor belts 102, 103, 104 of the conveyor module 100.

The active pulleys 203 to 206 and 215 to 217 are of the same diameter. The drive pulleys 213, 214 are of smaller diameter.

The acceleration means is pivoted from a rest position shown in broken lines in FIG. 7 to an active position where it encloses the object which is then accelerated by the cooperation of the belts 201, 202 of the transfer means and belts 213, 214 of the acceleration means, the stop barrier BA4 then being retracted.

To do this, the axis 219 is secured to the axis 230 by an arm 231. This arm 231 is moreover held by a rod 232 articulated by a rotary articulation 233 and a ball joint 234 connected to an electromagnet 235 which activates the pivoting.

The injector module 300 will now be described with reference to FIGS. 8, 9 and 10.

This module comprises a means of downward transfer, a pressure means and a retractable shutter forming a support surface perpendicular to the support surface 2.

The downward transfer means consists of a roller 301 driven in continuous rotation by a motor 302 by means of a belt 303. This roller 301 is tangent to the bearing surface 2 by an opening 304.

The pressure means consists of three rollers 305 mounted free to rotate about a common horizontal axis 306 itself mounted on a frame 307 pivoting about a horizontal axis 308. This frame 307 is actuated by an electromagnet 309 single acting through a double ball joint 310 and returned by a spring 314.

The shutter comprises a profile 311 articulated around a horizontal axis 312. In the active position, it extends the support surface 3. This shutter is actuated by an electromagnet 313. In the retracted position, it frees passage downwards for fold 1.

The injector module is also provided with a deflector 315 intended to correctly orient the objects having a trajectory. curve. This deflector is retractable and activates, during its movement, a detector which controls the immediate stop of the carousel if an object gets crooked during its descent.

The method of implementing the loading device described above will now be specified with reference to FIG. 11. The latter is a schematic top view of the device installed on a loading machine.

An input antenna 4 is arranged perpendicular to the carousel of vertical buckets 6, 7. It is connected to the device by an auxiliary conveyor 5 provided with a stop barrier BA0 and a sensor C0, such as a photoelectric cell .

Sensors C1 to C3 are also located near the stop barriers BA1 to BA3.

Barrier BA0 is normally closed, barriers BA1, BA2, BA3 normally open.

In the presence of a flat object, in particular a mail fold in abutment on the barrier BA0 detected by C0, this barrier is open and the fold is transferred to the accelerator module.

If other objects are brought before the evacuation of this fold of the accelerator module, the barriers BA3, then BA2, then BA1 are closed.

This is an important function of the conveyor module. Each input antenna must ensure the arrhythmia of the entry of the postal code of the mail when it is carried out by an operator, whether the presentation of the folds is ensured by the operator or by an automatic destacker. This arrhythmia, which characterizes the inflow of objects, requires the interposition of means allowing a buffer stock of objects to be produced before transferring them into the carousel animated with a uniform movement.

For input antennas equipped with an automatic recognition and indexing system, the residual arrhythmia is located at the destacker for which the rate of two objects per second is an average value liable to fluctuate, making it useful to existence of a buffer stock.

Finally, when the portion of the conveyor near the antennas input is occasionally and temporarily saturated, the existence of a buffer stock allows operators to overcome this saturation.

• le capteur C4 détecte un pli sur le module accélérateur , autorise l'ouverture de la barrière BA4 si le capteur C6 est désocculté, actionne l'électro-aimant 235 et donne l'ordre de fermeture de la barrière BA4 après désoccultation.
• le capteur C5 détecte le front arrière de l'objet et autorise la commande d'injection après temporisation (en actionnant les électro-aimants 309 et 313) ; il faut et il suffit que la cellule C5 soit désoccultée une fois pour autoriser l'injection ; si elle est réoccultée suite à un rebond, l'ordre est déjà transmis.
• le capteur C6 détecte la présence d'un pli dans le module injecteur.
• le capteur C7 détecte le front arrière d'un pli dans le module injecteur et donc le transfert de ce pli et donne alors l'autorisation de mise en condition initiale du module injecteur ; si l'occultation est trop longue (par rapport à une temporisation), un coincement du pli est détecté et la machine de tri est arrêtée ; si un retard de l'occultation est détecté (il peut détecter le front avant du pli), l'information que l'objet est ralenti est donnée ; si l'occultation est intempestive, il détecte une fausse direction.
• le capteur C8, sur la trajectoire des godets, permet la synchronisation et détecte la position correcte du godet pour son chargement.

Once at the accelerator module, the object is stopped by the BA4 barrier, which is normally closed. The implementation process is then as follows:

• the sensor C4 detects a fold on the accelerator module, authorizes the opening of the barrier BA4 if the sensor C6 is deactivated, actuates the electromagnet 235 and gives the order to close the barrier BA4 after deactivation.
• the sensor C5 detects the rear edge of the object and authorizes the injection control after delay (by actuating the electromagnets 309 and 313); cell C5 must be deactivated once and is sufficient to authorize injection; if it is concealed following a rebound, the order is already transmitted.
• sensor C6 detects the presence of a fold in the injector module.
• the sensor C7 detects the trailing edge of a fold in the injector module and therefore the transfer of this fold and then gives the authorization for initial conditioning of the injector module; if the occultation is too long (in relation to a time delay), a fold jam is detected and the sorting machine is stopped; if a delay in occultation is detected (it can detect the front edge of the fold), the information that the object is slowed down is given; if the occultation is untimely, it detects a false direction.
• sensor C8, in the bucket path, allows synchronization and detects the correct position of the bucket for loading.

As an indication for a carousel conveying a flow rate of six objects per second, the period of passage of a bucket under the injector module is T substantially equal to 0.166 seconds. Objects must be transferred to the injector module at a maximum rate compatible with their insertion into the cups. This transfer must therefore take place with a period equal to T or a multiple of T.

Thus, if all the successive buckets are fed by the same input, this must ensure a supply frequency of 166 ms; if one bucket in two is fed by input, the feeding period is 333 ms: and 500 ms, if one bucket in three is fed.

The latter rate of two objects per second was chosen to ensure in particular the reliability of the injection, a satisfactory lifetime and a sound level. This 500 ms cycle starts from the instant of the triggering of the command making it possible to create the pulse which will propel the object contained in the accelerator module and ends at the moment when its complete exit from the injector module is detected. We can then authorize the following object to enter the injector module.

Upstream of the accelerator module, objects move at a speed of 1.3 m / s. This value is a compromise ensuring their correct behavior and the rate of 2 objects / s.

• le module injecteur étant libre, la pénétration est réalisée par l'impulsion communiquée à l'objet déjà en mouvement (barrière d'arrêt escamotée à la sortie du module accélérateur).
• le module injecteur étant occupé par l'objet précédent, l'objet à transférer est provisoirement immobilisé par la barrière d'arrêt BA4 en sortie du module accélérateur puis subira l'impulsion au moment où celle-ci s'effacera.

To enter the injector module, there are two solutions:

• the injector module being free, penetration is achieved by the impulse communicated to the object already in motion (stopping barrier retracted at the output of the accelerator module).
• the injector module being occupied by the preceding object, the object to be transferred is temporarily immobilized by the stop barrier BA4 at the output of the accelerator module and will then undergo the impulse when it disappears.

To avoid an additional cause of dispersion of the law of movement of objects, the same speed setting conditions are systematically applied to all objects.

The solution where these are accelerated from an initial state of rest imposed by the closing of the stop barrier BA4 was therefore adopted.

So that the transfer of the object into the injector module is satisfactory whatever its type (included in the spectrum of mail to be processed) the transfer and acceleration means of the accelerator module are driven at a speed 1.8 m / s. This speed ensures complete penetration into the injector module, the possible rebounds that can be absorbed, for example, by a shock absorber that the front edge of the object strikes.

• du temps de réponse après cet ordre d'injection (ouverture du volet d'obturation et mise en action du moyen de pression du module injecteur),
• du temps de parcours des 50 mm environ qui séparent le le bord inférieur du module injecteur du bord d'entrée du godet.

The instant of arrival of the lower edge of the object at the level of the entry of a bucket presents a delay with respect to the instant of the injection order, due to:

• response time after this injection order (opening of the shutter and actuation of the pressure means of the injector module),
• travel time of approximately 50 mm separating the lower edge of the injector module from the inlet edge of the bucket.

This time is variable because it depends on the mass of the object: it increases the injection time the more it is higher.

It is therefore necessary to give the injection order when the recipient bucket has not arrived directly above the injector module. This distance must be such that the fastest object will not come up against the front face (in the direction of movement) of the bucket.

But it is also necessary that the slowest and thickest object (in general the heaviest) can still penetrate the bucket and that, this being achieved, the friction of the object on the internal face of the rear wall of the bucket concerns only a small fraction of its height.

The delay taken by a heavy object compared to a light object has the consequence that, for the maximum thickness, the filling of the bucket must take place while the latter is moving about 35 mm or for a period of about 85 ms.

An injection speed of 3.8 m / s satisfies this objective given that an object travels a distance of the order of 250 mm at this speed, which corresponds to the maximum height of the objects to be treated.

The speed of 1.8 m / s communicated by the accelerator module and the speed of 3.8 m / s communicated by the injector module satisfy a cycle of 500 ms.

Claims (14)

1. A feed device for feeding a sorting machine for sorting flat objects and including at least one input feeder (4) for the objects and pockets (6, 7) to which the objects are fed vertically for transport and discharge into output containers, the feed device allowing the objects to be conveyed one by one from the input feeder towards a vertical pocket and comprising a conveyor module substantially perpendicular to the path of the pockets and associated with a vertically downwards transfer device for transferring the objects into the pockets, the device being characterized in that:
      the conveyor module (100) comprises at least two stop gates (BA1, BA2, BA3) spaced by a distance greater than the maximum length of the objects (1),
      an accelerator module (200) is located between the conveyor module (100) and the vertical transfer device and comprises a downstream stop gate (BA4),
      the vertical transfer device is formed by an injecting module (300),
      these modules (100, 200, 300) being provided with continuously operating positive entrainment devices and the stop gates being retractable and controlling the movements of the objects in response to detectors located in the path of the objects.
2. A device according to claim 1, characterized in that the three modules (100, 200, 300) are in line and comprise a backing surface (2) for objects (1) inclined relative to the vertical plane.
3. A device according to claim 2, characterized in that each stop gate is formed by a retractable pin (120, 220) passing through the backing surface (2) in operative position and being fixed to a lever (121, 221) pivoting about a horizontal axis (122, 222) and actuated by an electromagnet (123, 223).
4. A device according to claim 2, characterized in that the conveyor module (100) and the accelerator module (200) comprise a support surface (3) perpendicular to the backing surface (2).
5. A device according to claim 4, characterized in that the backing surface (2) and the support surface (2) of the conveyor module (100) are provided with continuously operating conveyor belts (102, 103, 104).
6. A device according to claim 5, characterized in that the conveyor module (100) is provided with a freely rotating pressure wheel (111) near to each stop gate and mounted at the end of a lever (112) pivoting about an axis (113) perpendicular to the support surface (3) and biased by a spring (115).
7. A device according to claim 4, characterized in that the accelerator module (200) includes transfer means and accelerating means pivoting between a rest position and an active position in which the object (1) is held between these two means, which are rotated continuously.
8. A device according to claim 7, characterized in that the transfer means is formed by at least one pair of pulleys (203 to 206) mounted respectively on two shafts (207, 208) parallel to the backing surface (2), at least one endless belt (201, 202) being fitted on the pulleys.
9. A device according to claim 7 or 8, characterized in that the accelerating means is formed by at least one endless belt (213, 214) in tension over at least one pair of pulleys (215 to 218) mounted on two shafts (219, 230) which are fixed together and of which one is pivoted and actuated by an electromagnet (235).
10. A device according to claim 2, characterized in that the injecting module comprises transfer means acting downwards, tangentially with respect to the backing surface (2), pressure means pivoting about a horizontal axis and a retractable blocking shutter forming a support surface perpendicular to the backing surface (2).
11. A device according to claim 10, characterized in that the downwardly acting transfer means is formed by a continuously driven roller (301) rotating about a horizontal axis.
12. A device according to claim 10, characterized in that the pressure means is formed by at least two wheels (305) rotating freely about a horizontal shaft (306) mounted on a frame (307) which pivots about a horizontal axis (308) and is actuated by an electromagnet.
13. A device according to claim 10, characterized in that the blocking shutter (311) pivots about a horizontal axis (312) and is operated by an electromagnet (313).
14. A method of operating a feed device according to any one of the preceding claims, characterized in that photoelectric sensors are located in the path of the objects in order to control the movements thereof, and in that:
       the stop gates (BA1, BA2, BA3) of the conveyor module (100) are normally open and are closed when a letter arrives, if a letter (1) is present and arrested at the following stop gate (BA2, BA3, BA4); and
       the stop gate (BA4) of the accelerator module (200) is normally closed and is opened after arrival of a letter if no letter is detected in the injecting module (300).

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