Device for conveying and separating objects

Abstract

The invention relates to a device for conveying and separating (6) objects (2) comprising a conveyor (7) designed to convey said objects in a certain conveying direction (D1), said conveyor comprising a succession of conveying sections (8) independently motorized and distributed one after the other in the conveying direction, sensors (9) designed to generate digital data representative of the detection of presence or absence of an object transported on each conveying section, and a central unit (10) configured to control the speed of the conveying sections independently of each other as a function of said digital data representative of the detection of presence or absence of an object transported so as to distribute the objects on the conveyor in predetermined steps (PP).The central unit according to the invention is configured to constantly maintain at least two adjacent conveyor sections transporting the same object at the same speed. Figure to be published: 8.

Description

Title of the invention: Device for conveying and separating objects Technical field

[0001] The invention falls within the field of sorting objects and relates more particularly to a device for conveying and separating objects.

[0002] The invention also relates to an object sorting installation comprising such an object conveying and separation device. Prior art

[0003] Today there are installations for sorting objects such as parcel sorting installations comprising a high-speed sorting conveyor designed to sort the parcels according to a certain sorting indication and parcel input lines designed to receive the parcels in bulk, put said parcels in series and then space them apart from each other while respecting determined pitches before inserting them onto the sorting conveyor.

[0004] To space the packages apart from each other while respecting determined pitches, each input line is equipped with a conveying and separation device, also called a “centering module”, such as that described in patent application US2022112034.

[0005] The distribution of the packages according to the determined steps makes it possible to guarantee the correct functioning of the weighing steps, reading of sorting information and injection onto the sorting conveyor while limiting the risk of rejection.

[0006] Conveying and separating devices typically comprise a series of independently motorized, variable-speed conveying sections that are accelerated or slowed down to position the packages in their path.

[0007] Each conveying and separating device is also equipped with an optical system responsible, for example, for analyzing the outline of each package to estimate the position of its geometric center and deduce the leading conveying section when the package straddles several conveying sections.

[0008] However, it is common for the position of the geometric center of a package to differ from the position of its center of gravity, giving an "unbalanced" effect to the object and causing the package to shift or pivot in its pitch during transitions between two conveyor sections moving at different speeds.

[0009] This “unbalanced” effect is particularly important in packages that are heterogeneous in size, material, shape or density, such as International Small Packets (IPS). Summary of the invention

[0010] The objective of the invention is therefore to solve the aforementioned problems.

[0011] To this end, the invention relates to a device for conveying and separating objects comprising a conveyor designed to convey said objects in a certain conveying direction, said conveyor comprising a succession of independently motorized conveying sections distributed one after the other in the conveying direction, sensors designed to generate digital data representative of the detection of the presence or absence of an object transported on each conveying section, and a central unit configured to control the speed of the conveying sections independently of one another as a function of said digital data representative of the detection of the presence or absence of an object transported so as to distribute the objects on the conveyor in predetermined steps,characterized in that the central unit is configured to constantly maintain at least two adjacent conveyor sections transporting the same object at the same speed.

[0012] The idea behind the invention is to force objects to cross conveyor sections at the same speed to reduce the risk of shifting or pivoting in the path of the objects.

[0013] It will therefore be understood that to accelerate or decelerate an object to put it in its place, the conveyor sections transporting this same object will be driven at isospeed.

[0014] The device for conveying and separating objects according to the invention may also have the following particularities:

[0015] - the central unit is configured to identify at least one conveyor section not transporting an object downstream in the conveying direction relative to a conveying section transporting an object upstream in the conveying direction and at a certain conveying speed, and for controlling in return the acceleration or deceleration of said at least one downstream conveying section up to said certain conveying speed of the upstream conveying section;

[0016] - the central unit is set to calculate a certain useful length of the conveyor corresponding to the cumulative length of all the conveying sections of the conveyor to which is added a length corresponding to a predetermined percentage of the total length of an object to be conveyed, then to control the stopping of the acceleration or deceleration of the most downstream conveying section of the conveyor at the latest when said length corresponding to said certain predetermined percentage of the length of the object has left the downstream conveying section;

[0017] - the central unit is configured to calculate a time shift of an object by relative to the center of the step in which it must be positioned and to order in return the acceleration or deceleration of the conveying sections in the conveying direction to center the object in its pitch;

[0018] - the central unit is configured to control the drive of the sections of conveyance transporting the same object by imposing a ceiling speed level and a floor speed level and in that the central unit is configured to modulate the duration of maintaining at least one of the ceiling or floor speed levels as a function of the cumulative length of the conveyance sections and the length of the object;

[0019] - the central unit is set to control acceleration or deceleration conveyor sections transporting the same object by imposing a minimum amplitude speed level and a maximum duration;

[0020] - each conveying section extends along a certain first length L1 in the conveying direction and along a certain second length L2 transversely to the conveying direction, said first length being less than the second length;

[0021] - each conveyor section comprises a conveyor belt equipped with a snap ring and a sliding sole for the belt comprising guides for the rods;

[0022] - the conveyor comprises an inter-junction blade arranged between each belt;

[0023] - the blades are inclined substantially upwards in the conveying direction;

[0024] - the conveyor sections are distributed in a staircase in the direction of conveying, such that each downstream conveying section extends below an upstream conveying section.

[0025] The invention also extends to an object sorting installation comprising a sorting conveyor designed to convey and sort the objects into sorting outlets according to a certain sorting indication and an input line designed to supply the sorting conveyor with objects, said input line comprising an object conveying and separation device according to the invention. Summary presentation of the drawings

[0026] The present invention will be better understood and other advantages will appear on reading the detailed description of an embodiment taken as a non-limiting example and illustrated by the appended drawings, in which:

[0027] - [Fig.l] [Fig.l] illustrates very schematically an object sorting installation according to the invention;

[0028] - [Fig.2] [Fig.2] is a graph representing the first correction cycle according to the invention in the case of correcting a significant delay of an object whose entry and exit speed on the conveyor are different;

[0029] - [Fig.3] [Fig.3] is a graph representing the first correction cycle according to the invention in the case of correction of a moderate delay of an object;

[0030] - [Fig.4] [Fig.4] is a graph representing the first or second cycle of correction according to the invention in the case of correction of a small delay of an object;

[0031] - [Fig.5] [Fig.5] is a graph representing the second correction cycle according to the invention in the case of a correction of a strong delay of an object equivalent to that of the object of [Fig.l];

[0032] - [Fig.6] [Fig.6] is a graph representing a correction cycle according to the invention aiming to advance a first delayed object 2A, followed by another correction cycle according to the invention aiming to delay an advanced object 2B;

[0033] - [Fig.7] [Fig.7] is a graphical representation of the speeds of the first three conveying sections of the conveyor for carrying out the correction cycles of two consecutive objects of [Fig.6] according to the invention;

[0034] - [Fig.8] [Fig.8] illustrates very schematically a conveying and separation according to the invention;

[0035] - [Fig.9] [Fig.9] illustrates very schematically a sliding base according to the invention;

[0036] - [Fig. 10] [Fig. 10] illustrates very schematically the upstream end and the downstream end of two adjacent conveyor sections seen from the side and separated by an inter-junction blade according to the invention. Description of an embodiment

[0037] The sorting installation 1 for objects 2 according to the invention shown in [Fig.l] is particularly well suited to equipping a postal sorting center or a logistics platform.

[0038] By objects 2, we mean all types of objects such as parcels or packages, for example PPIs (for "Small International Packets") but also letters or any other object that can be processed in postal or logistics sorting installations.

[0039] The sorting installation 1 for objects 2 according to the invention typically comprises a sorting conveyor 3 designed to convey and sort the objects 2 into sorting outlets 4 according to a certain sorting indication affixed to each object 2 and an input line 5 designed to supply the sorting conveyor 3 with objects 2.

[0040] The input line 5 will here comprise a conveying and separating device 6 according to the invention also called a “centering module” designed to convey the objects in a certain conveying direction DI and space the objects from each other according to predetermined pitches PP.

[0041] The conveying and separating device 6 typically comprises a conveyor 7 designed to convey said objects in the conveying direction D1, formed of a plurality of conveying sections 8 independently motorized and distributed one after the other in the conveying direction DL

[0042] The conveyor 7 will also comprise a plurality of sensors 9, here by way of example optical sensors, designed to generate digital data representative of the detection of presence or absence of an object 2 transported on each conveying section 8.

[0043] The conveying and separating device 6 according to the invention will also comprise a central unit 10 configured to control the speed of the conveying sections 8 independently of each other as a function of said digital data representative of the detection of presence or absence of transported object 2, so as to distribute the objects on the conveyor 7 in the predetermined steps PP.

[0044] By predetermined steps, we mean a certain spacing between two successive objects 2, guaranteeing in particular good injection onto the sorting conveyor 3, reliable detection of certain data such as the weight and the destination address, and a reduction in the risks of collision between objects 2 which follow one another.

[0045] If the predetermined steps PP can have a physical step which fluctuates during the conveying of the objects 2 on the conveying sections 8 in response to the modification of speed of the conveying sections 8, the predetermined steps PP will always have a constant time step.

[0046] Now, each object 2 is at one time or another during its transport on the conveyor 7, straddling several conveyor sections 8.

[0047] Thus, another function of the central unit 10 is to constantly maintain at isospeed at least two adjacent conveyor sections 8 transporting the same object 8.

[0048] This makes it possible to reduce the risk of shifting or pivoting in the predetermined pitch PP of the objects 2 while the objects 2 are crossing two or more conveyor sections 8.

[0049] Preferably, but not necessarily, the central unit 10 will be able to constantly maintain at the same speed all of the conveyor sections 8 transporting the same object 2.

[0050] The central unit 10 may also be configured to identify at least one conveying section 8 not transporting an object 2 downstream in the conveying direction DI relative to a conveying section transporting an object upstream relative to the conveying direction DI and according to a certain conveying speed.

[0051] In response, the central unit is then configured to control the acceleration or deceleration of said at least one downstream conveying section 8 to said certain conveying speed of the upstream conveying section 8.

[0052] This setting makes it possible to accelerate or slow down the conveyor sections 8 as quickly as possible to the desired speed when they are not transporting objects 2.

[0053] This also makes it possible to avoid having significant speed changes applied to the conveyor sections 8 transporting an object 2 and therefore to reduce the risk of slipping and pivoting of the objects 2.

[0054] The central unit 10 may also be configured to, from the digital data representative of the detection of presence or absence of an object 2 on a conveying section 8, calculate a time offset of the object 2 inserted on the conveyor 7 relative to the center of the predetermined pitch PP in which it must be positioned and to control in return the acceleration or deceleration of the conveying sections 8 in the conveying direction DI to center the object 2 in its pitch.

[0055] For this, the central unit 10 includes in memory data representative of the time step to be imposed on the objects 2 on the conveying and separation device 6 according to the invention.

[0056] The time step may vary depending on the type of objects to be conveyed.

[0057] The idea here is to center each object 2 in its pitch so as to optimize the weighing, the detection of sorting indication and injection on the sorting conveyor 3.

[0058] To ensure the insertion of the objects 2 in their pitch and / or their centering in their pitch, the central unit 10 can be configured to vary the speed of the conveyor sections 8 by following correction cycles.

[0059] The acceleration and deceleration amplitude of the conveyor sections 8 may in particular be set at the maximum tolerable value without risk of slipping of the objects 2 (here for example 5 m / s2).

[0060] In order to preserve the stability of the object 2 during its insertion onto the conveying and separation device 6, the central unit 10 may be configured to command the start of a correction cycle only when the object 2 has completely entered the conveying and separation device 6 and to command the stopping of the correction cycle at the latest when a certain percentage of the length L of the object 2 has left it.

[0061] When an object 2 arrives at the entrance of the conveying and separation device 6, its leading edge and its trailing edge are detected by the sensors and a time shift Dt of the center of the predetermined step PP relative to the center of the object 2 is calculated (Dt<0 if the object 2 is ahead in its step, Dt>0 if the object 2 is behind).

[0062] A lead or lag correction cycle is therefore calculated by the central unit 10 by choosing the stage speed Vm between a minimum stage speed Vmin and a maximum stage speed Vmax to be reached and by calculating its holding time Tm to compensate for the difference Dt completely if possible. • If the object is ahead (Dt<0), object 2 is delayed, i.e. its speed is reduced to increase the travel time of the conveying and separation device 6 by -Dt, • If the object is late (Dt>0), object 2 is advanced, i.e. its speed is increased to reduce the travel time of the conveying and separation device 6 by +Dt.

[0063] Thus, if the object 2 is shifted by a certain time shift Dt, the duration of the crossing of the conveying and separation device 6 must be: T0 - Dt.

[0064] T0 being the reference duration and corresponding to the travel time of the conveying and separation device 6 from end to end by an object 2 of any length, centered in its pitch on arrival and which therefore does not have to be corrected.

[0065] As an example, two correction cycles are described here:

[0066] A first correction cycle consists of controlling the drive of the conveyor sections 8 transporting the same object 2 by imposing a ceiling speed level and a floor speed level.

[0067] The central unit 10 is then configured to modulate the duration of maintenance of at least one of the ceiling or floor speed levels as a function of the cumulative length of the conveying sections 8, the length of the object and the desired correction.

[0068] Ceiling speed thresholds V+ and floor speed thresholds V- will for example be chosen between the minimum landing speed Vmin and the maximum landing speed Vmax to best cover the target correction range (determined as a function of the length of the conveyor 7 and the length range of the objects 2).

[0069] For a strong correction of a delay or an advance of an object 2 in relation to its pitch, the speed level Vm retained will be V+ (or V-), here V- in [Fig.2].

[0070] For a moderate correction of a delay or an advance of an object 2 in relation to its pitch, the speed level Vm retained will be less than V+ or greater than V-, here greater than V- in [Fig.3].

[0071] For a small correction of a delay or an advance of an object 2 with respect to its pitch, the cycle can be limited to passing from its entry speed Ve on the conveyor 7 to its exit speed Vs from the conveyor 7 at the right time. The speed level Vm will therefore be Ve, as visible in [Fig.4]. This avoids shaking an object unnecessarily by applying a double speed variation to it.

[0072] A second correction cycle consists of controlling the acceleration or deceleration of the conveyor sections 8 transporting the same object 2 by imposing a speed level of minimum amplitude and maximum duration.

[0073] This correction cycle consists of applying a speed level Vm which is maintained throughout the crossing of the conveying and separation device 6.

[0074] For a strong correction of a delay or an advance of an object 2 in relation to its pitch, the speed level Vm retained will be lower than V+ or higher than V-, here higher than V- in [Fig.5] and maintained as long as possible before the object is brought up to speed at the output speed Vs.

[0075] The interest of the second correction cycle is to minimize the duration of the acceleration and deceleration phases which risk destabilizing the objects 2.

[0076] The variations in idle speed of the conveyor sections 8 will also be shortened.

[0077] As an example, the strong correction of a delay via the first correction cycle requires a plateau speed of 0.6 m / s while via the second correction cycle only 0.98 m / s is necessary, as visible in [Fig.5].

[0078] As an example, [Fig.6] describes the case of a first object 2A that is late requiring a correction cycle to advance it followed by an object 2B that is ahead requiring a correction cycle to delay it. The dotted arrow here represents the gap E between object 2A and object 2B.

[0079] The central unit 10 may also be configured to favor a correction of the object furthest downstream on the conveyor 7 in the conveying direction DI to the object furthest upstream on the conveyor 7.

[0080] [Fig.7] represents the speeds of the first three conveying sections 8 of the conveyor 7.

[0081] The conveying sections 8A, 8B and 8C are first based on the correction cycle of the most downstream object 2, then on the one which follows it upstream in the conveying direction DI by adapting the conveying speed of each conveying section 8 to the conveying speed determined for the following object 2 as soon as it is released from the first object 2.

[0082] The central unit 10 may also be configured to optimize the correction cycles by considering a “useful” length of the conveyor 7 greater than the actual length of the conveyor 7 and corresponding to the cumulative length of all the conveying sections 8 of the conveyor 7 to which is added a length corresponding to a certain percentage of the total length of an object 2 being conveyed on the conveyor 7.

[0083] This function here makes it possible to take advantage of the heterogeneity of the distribution of the weight of the object 2, generally greater towards the center of the object 2 and less significant towards the edges, in order to continue the correction cycle of the object 2 even if the object 2 is straddling the conveyor 7 and an output conveyor CS downstream of the conveyor 7.

[0084] The mass at the front of the object 2 is considered here as an example as negligible compared to the central mass of the object 2 which makes it possible to maintain a certain change of speed between the last conveying section 8 of the conveyor 7 furthest downstream in the conveying direction and the output conveyor CS without risking rotating the object 2.

[0085] For this, the central unit 10 includes in memory at least a certain percentage of the length of a type of object corresponding to a negligible mass compared to the rest of the length of the object 2, for example 20% of the length of the object 2 within the framework of the PPIs.

[0086] Thus in this example, the central unit 10 will be configured to recover length data of the object 2, for example from the data representative of the detection of the presence of an object 2 transported on the conveying section 8 furthest upstream in the conveying direction or else by a detection process upstream of the conveying and separation device 6, then to control in return the maintenance of the correction cycle over the entire “useful” length of the conveyor 7.

[0087] Also, in the case where an object 2 cannot be correctly recentered in its pitch, a third correction cycle may aim to avoid its overflowing from the predetermined pitch PP without seeking to center it as best as possible in its pitch so as to favor the correction of the following object 2 by maximizing the capacity of the conveying and separation device 6 to process it without risk of speed conflict.

[0088] To perfect the centering of unstable objects 2 which could gradually move out of their position during conveying, the correction cycles can be recalculated during the travel of the object 2 on the conveying and separation device 6 (for example at the exit of the first three conveying sections 8) taking into account the actual position of the object 2 in relation to its theoretical position.

[0089] The advantage provided by the specific parameter(s) of the central unit 10 is here optimized by conveyor sections 8 according to the invention, visible in [Fig.8], designed to be compact and efficient.

[0090] Indeed, it may be provided that each conveying section 8 extends along a certain first length L1 in the conveying direction DI and along a certain second length L2 transversely to the conveying direction D1, said first length L1 being less than the second length L2.

[0091] The conveyor sections 8 are therefore wider than they are long.

[0092] Thus, for a certain length of conveyor 7, many sections of conveyance 8 can be arranged one after the other, which allows control adapted to a large heterogeneity of objects 2, in length, weight and density.

[0093] More particularly and as shown in Figures 8 and 9, each conveying section 8 may comprise a transport belt 11 equipped with a rod 12 and a sliding base 13 for the belt 11 comprising a guide 13A for the rods, here for example a guide groove.

[0094] Indeed, the shorter the conveying sections 8, the more difficult it is to guide the belts 11 in the conveying direction D1.

[0095] It may also be provided that each belt 11 is mounted on a downstream idler roller 14A and an upstream idler roller 14B in the conveying direction D1 and that each conveying section 8 comprises a device 15 for adjusting the parallelism of its belt 11.

[0096] More specifically, the parallelism adjustment device 15 is designed to maintain the eccentric located on the downstream idler roller 14A in the conveying direction D1, also called the output roller.

[0097] The parallelism adjustment device 15 here makes it possible to limit the forces on the ring 12 and therefore to reduce the risks of breakage but also to avoid the appearance of a bump on the top of the belt 11 when the ring 12 rests a little too much on its guide 13 A.

[0098] The parallelism adjustment device 15 will comprise for example an eccentric with an axis integrated on bearings accepting this potential offset.

[0099] Thus, thanks to the presence of the rod 12 and its guide 13A and the parallelism adjustment device 15, the conveying sections 8 can have a first length L1 as small as possible, here of the order of 175mm and a second length L2 equivalent to the width of the conveyor 7, here of the order of 550mm.

[0100] The conveyor 7 of the conveying and separation device 6 according to the invention may also comprise an inter-junction blade 16, visible in FIGS. 8, 9 and 10, arranged between each belt 11 and more specifically between the downstream idler roller 14A of an upstream conveying section 8 and an upstream idler roller 14B of a downstream conveying section 8 in the conveying direction DL.

[0101] The inter-junction blades 16 will therefore be arranged so as to be as close as possible to the conveying sections 8, so as to reduce the space between two adjacent conveying sections 8.

[0102] The inter-junction blades 16 make it possible on the one hand to avoid jamming of objects 2 between two adjacent belts 11 and on the other hand to minimize the shaking of the objects 2 when crossing the conveyor sections 8 by minimizing the amplitude and duration of the instability of the objects 2 during the transitions.

[0103] More particularly and advantageously, the inter-junction blades 16 may be inclined substantially upwards in the conveying direction D1 so as to achieve the transitions as smoothly as possible.

[0104] The conveying sections 8 may also be distributed in a staircase fashion in the conveying direction D1, so that each downstream conveying section 8 extends below an upstream conveying section 8, in order to improve the transitions of object 2 from one conveying section 8 to another.

Claims

Claims

1. Device for conveying and separating (6) objects (2) comprising a conveyor (7) designed to convey said objects in a certain conveying direction (Dl), said conveyor comprising a succession of conveying sections (8) independently motorized and distributed one after the other in the conveying direction, sensors (9) designed to generate digital data representative of the detection of presence or absence of an object transported on each conveying section, and a central unit (10) configured to control the speed of the conveying sections independently of each other as a function of said digital data representative of the detection of presence or absence of an object transported, the central unit being configured to constantly maintain at iso-speed at least two adjacent conveying sections transporting the same object,characterized in that the central unit is configured to control said speed of the conveying sections so that the objects are distributed on the conveyor in predetermined steps (PP) and in that the central unit is configured to calculate a time offset of an object relative to the center of the step in which it must be positioned and to control in return the acceleration or deceleration of the conveying sections in the conveying direction to center the object in its step.,

2. Device for conveying and separating objects according to claim 1, characterized in that the central unit is configured to identify at least one conveying section not transporting an object downstream in the conveying direction with respect to a conveying section transporting an object upstream in the conveying direction and according to a certain conveying speed, and to control in return the acceleration or deceleration of said at least one downstream conveying section up to said certain conveying speed of the upstream conveying section.

3. Device for conveying and separating objects according to claim 1 or 2, characterized in that the central unit is configured to calculate a certain useful length of the conveyor corresponding to the cumulative length of all the conveying sections of the conveyor to which is added a length corresponding to a predetermined percentage of the total length of an object to be conveyed, then to control the stopping of the acceleration or deceleration of the most downstream conveying section of the conveyor at the latest when said length corresponding to said certain predetermined percentage of the length of the object has left the downstream conveying section.

4. Device for conveying and separating objects according to any one of the preceding claims, characterized in that the central unit is configured to control the driving of the conveying sections transporting the same object by imposing a ceiling speed level and a floor speed level and in that the central unit is configured to modulate the duration of maintenance of at least one of the ceiling or floor speed levels as a function of the cumulative length of the conveying sections and the length of the object.

5. Device for conveying and separating objects according to any one of claims 1 to 3, characterized in that the central unit is configured to control the acceleration or deceleration of the conveying sections transporting the same object by imposing a speed level of minimum amplitude and maximum duration.

6. Device for conveying and separating objects according to any one of the preceding claims, characterized in that each conveying section extends along a certain first length L1 in the conveying direction and along a certain second length L2 transversely to the conveying direction, said first length being less than the second length.

7. Device for conveying and separating objects according to any one of the preceding claims, characterized in that each conveying section comprises a transport belt (11) equipped with a rod (12) and a sliding base (13) for the belt comprising guides (13A) for the rods (12).

8. Device for conveying and separating objects according to any one of the preceding claims, characterized in that the conveyor comprises an inter-junction blade (16) arranged between each belt.

9. Device for conveying and separating objects according to claim 8, characterized in that the blades are inclined substantially upwards in the conveying direction.

10. Device for conveying and separating objects according to any one of the preceding claims, characterized in that the conveying sections are distributed in a staircase fashion in the conveying direction, so that each downstream conveying section extends below an upstream conveying section.

11. An object sorting installation comprising a sorting conveyor (3) designed to convey and sort objects into sorting outlets (4) according to a certain sorting indication and an input line (5) designed to supply the sorting conveyor with objects, said input line comprising an object conveying and separating device according to any one of the preceding claims.

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