METHOD FOR CONTROLLING AN OVERHEAD CONVEYOR SYSTEM

Abstract

TITLE: METHOD FOR CONTROLLING AN OVERHEAD CONVEYOR SYSTEM The invention relates to a method for controlling an overhead conveyor system for multi-stage transport devices. The conveyor system comprises: a main conveyor (6) for moving the transport devices (7) to an inlet (51) of the processing zone (5) and from an outlet (52) of said zone (5), an auxiliary conveyor arranged in the processing zone (5), and a means for transferring the transport devices (7). The method comprises the following steps: holding the device in an injection zone (Zi) upstream and adjacent to the inlet (51), sensing the device by the transfer means, receiving information that a drive device is available to the auxiliary conveyor, and transferring the transport device to bring it into contact with said drive device. Figure 1.

Description

Title of the invention: METHOD FOR CONTROLLING AN AIR CONVEYOR SYSTEM Technical field of the invention

[0001] The present invention relates to the field of overhead load conveying. More particularly, it relates to a method for controlling a conveying system of multi-shelf transport devices capable of transporting items to be processed in a processing area. State of the art

[0002] In this field, the transport of items to be treated is usually carried out using floor conveyors, which causes problems, including wear and tear on the onboard electronic and electromechanical components that are exposed to radiation during repeated passages through the treatment area. The solution found for this problem is to use an overhead conveyor system in which the item transport devices are suspended and moved along a circuit passing through the treatment area. Such a system has the advantage that only mechanical trolleys, from which the transport devices are suspended, pass through the treatment area. The absence of floor conveyors also provides improved irradiation performance, by allowing the item to be treated to be positioned directly in front of the treatment beam.

[0003] However, known overhead conveyor systems are not suitable for installations where products require specific processing. Indeed, in such a processing area, it is necessary for all items to undergo homogeneous treatment at sufficient doses. The process therefore requires low speeds and high stability, which is incompatible with the throughput generally imposed by the processing installation.

[0004] It is therefore important that the process control be well controlled.

[0005] The invention therefore aims to provide a solution for maintaining a nominal throughput in the processing plant while controlling the movement conditions of the transport devices within the processing area, thereby ensuring proper product processing. Summary of the invention

[0006] To this end, the invention relates to a method for controlling an overhead conveying system for suspended multi-stage transport devices, capable of carrying articles to be treated in a treatment area by an ionizing beam, the conveying system comprising: - a main conveyor having first-speed drive means, configured to move the transport devices to an entrance of the processing area and from an exit of said area, - an auxiliary conveying device arranged in the processing area and carrying a plurality of drive devices capable of driving successive and adjacent transport devices, from the entrance to the exit, at a speed determined according to the articles to be processed, said speed being lower than the first speed, and - a means of transferring transport devices, arranged near the entrance,

[0007] wherein the process comprises the following steps:

[0008] - a standstill of a transport device in an upstream injection zone and adjacent to the entrance,

[0009] - a seizure of the transport device by the means of transfer in the area injection,

[0010] - receiving information that a training device is available at auxiliary conveying device, and

[0011] - a movement of the transport device by the transfer means to put it in contact with said training device.

[0012] Placing a transport device in a standby position prevents collisions with other transport devices already driven by the auxiliary device, thus allowing for the optimal timing of its movement towards the processing zone. Furthermore, it ensures that adjacent transport devices continuously move in front of the processing beam, forming a train, so that the beam is always interrupted by a transport device and does not impact the wall in the background. This reduces energy losses. Moreover, it maintains the current flow rate by preventing disruptions.

[0013] The use of the auxiliary conveying device for movement and stabilization thus allows for good control of the stability and speed of the transport devices, which guarantees homogeneous processing. For example, the movement spacing is chosen so that the transport devices are close together in the processing zone. They thus form a kind of train, which avoids any energy loss that can occur if the devices are spaced apart.

[0014] The speed of movement can also be linked to the desired treatment dose for the products; this may be the case in particular when treating the products with radiation, the speed of movement can be decisive for the radiation dose received, for example, to sterilize the products.

[0015] The radiation is for example ionizing radiation, for example with X-rays, Gamma rays or an electron beam.

[0016] The method may further include: - A transport device is placed on standby in a preparation area upstream of the injection area. - Receiving information that a location is available in the injection zone, - A transfer of a transport device from said preparation area to the injection area via the main conveyor and optionally putting it on standby.

[0017] In this way, it is ensured that there is always a transport device ready to be transferred to the injection zone where it will be taken over by the transfer means. Thus, the pace is maintained.

[0018] The method may also include: - A holding period for one or more transport devices in an accumulation zone upstream of the preparation zone, - Receiving information that a space is available in the preparation area, - A transfer of a transport device from said accumulation area to the preparation area by the main conveyor and optionally put it on standby.

[0019] Advantageously, the method may further include at least one additional step of putting a transport device on standby in an additional accumulation zone.

[0020] The accumulation zones allow: - to always have transport devices ready to be injected into the automatic stations downstream in order to respect a certain pace imposed by the system while avoiding disrupting the flow. - to store enough transport devices to meet varying cadence requirements.

[0021] Advantageously, the process may include a step of identifying a transport device upstream of the treatment area. Identifying the transport device allows for monitoring of the treatment.

[0022] Advantageously, the method may further include a decision step to send a transport device to a rotation zone (R) in which the transport device is rotated 180° about its vertical axis. The rotation of the transport device ensures that the articles are exposed to the beam from both sides.

[0023] Advantageously, the method may further include a step of identifying a transport device downstream of the treatment area and a step of deciding whether said transport device should pass back through the treatment area or be directed to an exit.

[0024] Advantageously, the method may further include a decision step of directing a transport device to a reversing station in which articles from two levels of said device are reversed (top to bottom and vice versa) before passing again through the treatment zone. The reversal makes it possible to homogenize the treatment dose received by the articles placed on different levels.

[0025] The invention also relates to a computer program comprising instructions for executing the steps of the process as described above.

[0026] The invention also relates to a computer-readable medium comprising the computer program described above.

[0027] The invention further relates to an article processing installation in a processing area, comprising means for generating an ionizing beam and an overhead conveying system for suspended multi-stage transport devices capable of carrying articles to be processed, the conveying system comprising: - a conveyor having drive means at a first speed, configured to move the transport devices to an entrance of the processing area and from an exit of said area, - an auxiliary conveying device arranged in the processing area and carrying a plurality of drive devices capable of driving successive and adjacent transport devices, from the entrance to the exit, at a speed determined according to the articles to be processed, said speed being lower than the first speed, and - a means of transferring transport devices, arranged in the vicinity of the entrance.

[0028] The installation further includes a computer program described above.

[0029] The auxiliary conveying device may include a lower chain carrying drive means such as cleats.

[0030] Advantageously, the auxiliary conveying device may further include an upper chain comprising hooking means configured to latch onto guiding means arranged in the upper part of the loading devices, said upper chain being synchronized with the lower chain.

[0031] Having an upper chain synchronized with the lower chain allows for greater control of the position along its vertical axis of the transport devices, ensuring good stability by preventing swaying along the axis of advancement of the transport devices.

[0032] Synchronization between the upper and lower chains can be achieved by a synchronization tree or any other synchronization method, such as an additional chain. However, the synchronization tree has the advantage of being a simple synchronization method and of enhancing the stability of both the upper and lower chains. Brief description of the figures

[0033] Other features and advantages of the invention will become apparent from the following description in relation to the accompanying drawings, given by way of non-limiting examples, in which:

[0034] [Fig-1] [Fig.1] represents a partial view of an installation illustrating the operation of an aerial conveyor system according to the invention;

[0035] [Fig.2] [Fig.2] is a view of part of the conveying system showing a conveyor and a suspended transport device;

[0036] [Fig.3] [Fig.3] is a zoom on an area of ​​attachment of a transport device to a conveyor trolley;

[0037] [Fig.4] [Fig.4] is a partial view of a conveyor chain;

[0038] [Fig. 5] [Fig. 5] is a view of a set of transport devices in the area treatment.

[0039] In the following description, elements having an identical structure or analogous functions will be designated by the same references. Detailed description

[0040] Fig. 1 represents a schematic top view of a product processing installation 1 comprising a non-sensitive part I partially shown on the right of the figure and a sensitive part II on the left.

[0041] In Part I, the installation includes generally known storage and handling means; such means are not the subject of the invention and are therefore not detailed in this description.

[0042] In Part II, the installation comprises protective walls 2 enclosing an emission zone including means 3 for generating radiation used in the treatment of articles. The radiation-generating means 3 may be means for generating any type of radiation usable in the treatment of articles, for example, sterilizing radiation. Such radiation may be, for example, ionizing radiation by X-rays, gamma rays, or an electron beam.

[0043] In other embodiments not shown, the treatment may be different, such as surface treatment, paint spraying or any other reactive or aesthetic agent.

[0044] The beam 4 produced by the means 3 arrives at a treatment zone 5, the products which are in this zone at the time of impact receive a dose from the beam.

[0045] The protective walls are known per se and may comprise external walls 2 and an internal wall 21 to stop the beam 4 if it hits between two products or between two transport devices 7. It is not necessary here to give more details of such walls which are known per se for such applications.

[0046] To move the articles to be processed, the conveying system includes transport devices 7, an example of which is shown in [Fig.2] and [Fig.5]. Such devices may include several levels into which the articles to be processed are loaded.

[0047] To circulate the products to be treated with the beam 4, the installation includes an overhead conveyor 6 forming a circuit which goes from part I to part II. The products are loaded upstream of the inlet 60 and carried by the conveyor 6 to part II to pass through the treatment zone 5 to receive one or more doses from the beam, for example by making rotations in the internal loop 61. At the end of treatment the products exit through the outlet 62 to go to other stations of the installation in part I, for example to be unloaded and stored.

[0048] The conveyor 6, in the example of Figure 2, comprises a lower part including a running track 64 on which trolleys 8 move, each carrying a suspended transport device 7.

[0049] As shown in [Fig.3], a trolley 8 includes wheels 81 for rolling on the track 64 and a transport device 83 to which the transport device 7 is suspended. The trolley 8 further includes a hooking means 82 which can move from an upper hooking position, allowing the trolley 8 to be driven with the transport device 7, to a lower position to stop the trolley 8 and the transport device 7.

[0050] In the illustrated example, the conveyor is a double-rail conveyor, the upper rail 63 of which, as shown in [Fig.4], includes rolling means 91 of a traction chain 9. The traction chain rotates continuously and includes drive devices 92. When a drive device 92 meets the hooking device 82 in the upper position, the carriage is driven along a path predefined by the control system.

[0051] In other embodiments not shown, the conveyor may be monorail or of another type used in overhead conveyor systems.

[0052] In installation 1, the conveying of the transport devices 7 takes place outside the treatment zone 5 at a certain speed defined by the treatment process to maintain a certain rate. This speed is relatively high (typically 10 to 20 m / minute) compared to the speed of movement within the treatment zone 5. Within the treatment zone, this allows each product to receive the dose. To define the processing method and ensure homogeneous treatment of all products, it is necessary to ensure movement at a much slower speed (from only a few dm / minute to a few m / min) than in the rest of the circuit defined by the conveyor system. It is also necessary to guarantee the stability of the transport devices, each of which may have multiple shelves and a significant height, thus creating a risk of tipping.

[0053] To ensure proper processing of the products carried by the transport devices 7, the latter can be moved by moving the trolleys 8 by the traction chain 9 to the entrance 51 of the processing area 5, then the hooking device 82 can be moved to the lower position so that the drive of the trolley by the traction chain 9 stops.

[0054] To ensure the drive and stability of the transport devices 7 in the processing zone 5, the system includes an auxiliary conveying device arranged in said processing zone 5. According to the illustrated example, this device has drive means in its lower part configured to cooperate with lashing means 71 which are provided in the lower part of each transport device 7.

[0055] The auxiliary conveying device allows the movement of the transport devices 7 within the processing zone 5 to be controlled at a speed determined according to the items being processed and to ensure good stability. In fact, the drive means, for example in the form of cleats, prevent the transport devices from tipping over during their movement at the low speed defined by the travel increment.

[0056] As shown in the example of [Fig.5], the auxiliary conveying device may include a lower chain 13 composed of links 131 and carrying drive means 132 in the form of cleats.

[0057] It may also include an upper chain 12 composed of links 121 and carrying additional drive means 122, also in the form of cleats. The additional cleats are configured to cooperate with additional guiding means arranged in the upper part of the transport devices.

[0058] Advantageously, the upper chain 12 is synchronized with the lower chain 13. The synchronization between the upper chain 12 and the lower chain 13 can, for example, be carried out by a synchronization tree 14. Alternatively, the synchronization can be done by an additional chain.

[0059] Furthermore, to ensure the centering of the transport device 7, the system may also include a lower guide rail 11 arranged to receive a centering element, arranged in the lower part of the transport devices 7.

[0060] The system also includes a transfer device 10 as shown in [Fig. 2]. The device 10 is arranged to move the transport devices 7 from the waiting position, in the injection zone to put it in contact with the auxiliary conveying device.

[0061] The installation also includes a computer program which controls the operation of the installation. Example of operation:

[0062] Preparatory operations are carried out in the unshown portion of Part I; such operations may include: - the removal of items from stock, for example, placed on a customer's pallet - a transfer onto a secondary pallet bearing a means of identification, such as that a QR code engraved on said secondary pallet, to track the pallet, - a transfer of secondary pallets, each carrying a pallet containing items to be processed, into transport devices (7), for example on two or three floors.

[0063] The loaded transport devices 7 can undergo one or more identifications SI in part I, the system identifies each device 7 moved by the main conveyor 6 before arriving at the entrance 60, it then undergoes further identifications S2, S3 before the processing zone 5 and further S4, S5 after this zone 5. In this way, the system can individually track the transport devices 7 and determine the next destination.

[0064] The transport devices 7 arriving at the inlet 60 continue along the incoming circuit, passing through accumulation zones Za8, Za6, and Za4. Depending on the required throughput, the control process may include accumulation steps in each of these zones, releasing them one by one by activating an open / close (O / F) means. Upon exiting Za4, the devices 7 are sent one by one into the internal loop 61, passing through the processing zone 5, when the number of devices already present in this zone is less than the maximum capacity that the internal loop 61 can accept. They then arrive in an accumulation zone Za2 upstream of a rotation device R. Each transport device 7 exiting the accumulation zone Za2 is thus identified by the means S3, which can decide whether or not it needs to undergo a rotation step by the device R, which rotates it 180° to change the side exposed to the beam 4.Transport devices 7 that have already made one or more passes through the treatment zone 5 and been redirected to Za2 and exit the accumulation zone Za3 may also arrive at the accumulation zone. If rotation is not required, the devices 7 continue towards the downstream zone Zal.

[0065] The transport devices arriving at the accumulation zone Zal are systematically stopped to ensure proper control of the flow of devices 7 passing through the treatment zone 5 and exposed to beam 4. This first accumulation zone Zal allows to systematically have a reserve of transport devices 7 to send to zone 5 while avoiding forming holes in the train of devices 7 passing in front of the treatment zone 5.

[0066] To ensure proper flow control, a transport device 7 is sent to the preparation zone Zp as soon as a space becomes available in that zone. Then, if a space is free in the introduction zone Zi, said device is transferred from the preparation zone Zp to the introduction zone Zi. In this zone, the transport device 7 is prepared by being introduced into the processing zone 5, where the speed of movement is reduced. Furthermore, the auxiliary conveyor system is configured to allow the transport devices arriving at zone 5 to form a kind of train by remaining adjacent to one another as they move past the processing beam 4.When a space is available in the processing zone 5 (i.e., a means of driving the auxiliary conveyor device 2, 13 is available), the transfer device 10 moves the transport device present in the introduction zone Zi to the processing zone 5 to bring it into contact with the auxiliary conveyor device 2, 13 which ensures its drive between the inlet 51 and the outlet 52 of the processing zone 5. Then, the main conveyor 6 continues the conveyance of said device once it has reached the outlet 52 to pass it through the accumulation zone Za3 in which it can accumulate with other devices 7 if this is determined by the system.

[0067] Upon exiting zone Za3, an identification is performed by means S4, which allows the control program to determine a destination from among: - a new passage through the Za2 accumulation zone, to go through the steps described above again, or - directed to an exit 62, 63. A new identification by means S5 allows to decide whether the device has had a complete processing and should therefore be directed to the exit 62 to be unloaded and the items put back in stock, or the processing is partial and therefore it is sent to a reversing station (not shown) via the exit 63, then arrive again at the entrance 60 after reversing the lower pallets with the upper pallet.

[0068] Optionally, accumulations can be carried out in the Za5 and Za7 accumulation zones.

Claims

1.

2. Demands Method for controlling an overhead conveyor system for suspended multi-stage transport devices (7) carrying articles to be treated in a treatment area (5) by an ionizing beam, the conveyor system comprising: - a conveyor (6) having first speed drive means (VI), configured to move the transport devices (7) to an entrance (51) of the processing zone (5) and from an exit (52) of said zone (5), - an auxiliary conveying device (12, 13, 14) arranged in the processing zone (5) and carrying a plurality of drive devices (122, 132) capable of driving successive and adjacent transport devices (7), from the inlet (51) to the outlet (52), according to a through speed (V2) determined according to the articles to be processed, said through speed (V2) being lower than the first speed, and - a means of transferring (10) transport devices (7), arranged in the vicinity of the entrance (51), in which the process includes the following steps: - a standstill of a transport device (7) in an injection zone (Zi) upstream and adjacent to the inlet (51), - seizure of the transport device (7) by the transfer means (10) in the injection zone (Zi), - receiving information that a drive device (122, 123) is available to the auxiliary conveying device (12, 12, 14), and - a movement of the transport device (7) by the transfer means (10) to bring it into contact with said drive device (122, 123). A method according to the preceding claim, further comprising: - A transport device being put on hold in a preparation zone (Zp) upstream of the injection zone (Zi), - A receipt of information that a location is available in the injection zone (Zi), - A transfer of a transport device (7) from said preparation zone (Zp) to the injection zone (Zi) by the main conveyor (6).

3. A method according to the preceding claim, further comprising: - A standby of one or more transport devices in an accumulation zone (Zal) upstream of the preparation zone (Zp), - A receipt of information that a location is available in the preparation zone (Zp), - A transfer of a transport device (7) from said accumulation zone (Zal) to the preparation zone (Zp) by the main conveyor (6).

4. Method according to the preceding claim, further comprising at least one additional step of holding one or more transport devices (7) in an additional accumulation zone (Za2, Za3, Za4, Za5, Za6, Za7, Za8).

5. A method according to any one of the preceding claims comprising a step of identifying a transport device upstream of the treatment area (5).

6. Method according to the preceding claim further comprising a decision step to send a transport device to a rotation zone (R) in which the transport device (7) is rotated by 180°.

7. A method according to any one of claims 5 or 6, comprising a step of identifying a transport device (7) downstream of the treatment zone (5) and a step of deciding whether said transport device (7) should pass back through the treatment zone (5) or be directed to an exit (62).

8. A method according to any one of claims 4 to 7 further comprising a decision step to direct a transport device to a reversing station in which two-story articles of said device devices are reversed before a new pass through the treatment zone (5).

9. A computer program comprising instructions for executing the steps of the process according to any one of claims 1 to 8, in an article processing installation in a processing zone (5), comprising means for generating an ionizing beam (4), and an overhead conveying system for suspended multi-stage transport devices (7) carrying articles to be processed, the conveying system comprising: - a conveyor (6) having first-speed drive means (VI), configured to move the transport devices (7) to an inlet (51) of the processing zone (5) and from an outlet (52) of said zone (5), - an auxiliary conveying device (12, 13, 14) arranged in the processing zone (5) and carrying a plurality of drive devices (122, 132) capable of driving successive and adjacent transport devices (7) from the inlet (51) at exit (52),according to a scrolling speed (V2) determined according to the articles to be processed, said scrolling speed (V2) being lower than the first speed, and a transfer means (10) for transport devices (7), arranged in the vicinity of the entrance (51).

10. Computer-readable medium comprising the computer program according to the preceding claim.

11. Article processing installation in a processing area (5), comprising means for generating an ionizing beam (4) (3), and an overhead conveying system for suspended multi-stage transport devices (7) carrying articles to be processed, the conveying system comprising: - a conveyor (6) having first speed drive means (VI), configured to move the transport devices (7) to an entrance (51) of the processing zone (5) and from an exit (52) of said zone (5), - an auxiliary conveying device (12, 13, 14) arranged in the processing zone (5) and carrying a plurality of drive devices (122, 132) capable of driving successive and adjacent transport devices (7), from the inlet (51) to the outlet (52), according to a through speed (V2) determined according to the articles to be processed, said through speed (V2) being lower than the first speed, and - a means of transferring (10) transport devices (7), arranged in the vicinity of the entrance (51), the installation further comprising a computer program including instructions for executing the steps of the process according to any one of claims 1 to 8.

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