Object conveying and / or sorting system

Abstract

An object conveying system (10) is provided. The object conveying system comprises a guide plate (100) extending in a longitudinal direction (L), said guide plate (100) having at least one channel (101) for conveying an object (O) between a first end zone (102) and a second end zone (103), at least one object measurement unit (200) for conducting one or more measurements associated with a property of the object (O), and at least one ejector unit (300) arranged to eject the object (O). An object feed device (400) is arranged in the vicinity of the first end zone (102), said object feed device (400) having a central axis (A). The object feed device (400) is arranged such that the central axis (A) is positioned transversally in relation to the longitudinal direction (L) of the guide plate (100).

Description

[0001] OBJECT CONVEYING AND / OR SORTING SYSTEM

[0002] TECHNICAL FIELD

[0003] The present invention concerns a system for conveying and ejecting particular objects of a bulk of objects. More particularly, the present invention pertains to a system comprising a guide plate extending in a longitudinal direction, said guide plate having at least one channel for conveying an object between a first end zone and a second end zone, and at least one object measurement unit for conducting a measurement associated with at least one property of the object, and at least one ejector unit arranged to eject the object.

[0004] BACKGROUND

[0005] It is known to sort objects within a bulk of objects, such as grains, by means of a rotating cylinder or drum, which cylinder has pockets on the inside. This cylinder is rotating around a substantially horizontal axis, while being aligned with its longitudinal central axis coinciding with said horizontal axis. The objects, such as granules, are fed into one end of the cylinder, and as the cylinder rotates the granules will be lifted as they are captured in the pockets. The pockets are adapted in size and dimensions for receiving one object each. In the bottom of each pocket an opening is provided into the outside surface of the drum, such that for example light may be sent outside the drum, through the openings onto the objects, and being detected on the inside of the drum or reflected to be detected on the outside of the drum, or vice versa. In this way the object in the respective pocket may be illuminated with light, and reflection or transmission spectra may be obtained. From this spectra, characteristics of said objects may be obtained, which may be used to sort or fractionize said bulk of objects based on said characteristics. One or several collectors may then be placed in the vicinity of the drum, to receive - after characterization - a specified fraction based on information from a detector. A drum of this kind, and a machine comprising such drum, is disclosed in WO 2004 / 060585.

[0006] A problem associated with such a drum is that the opening may be occluded by the objects received therein, if the objects get stuck in the opening. Then this pocket will be useless for the rest of the fractionizing procedure. Another problem is that only a limited part of information from the object may be obtained. A third problem is that pocket size must be customized after the object size in three dimensions, and the drum must thus be customized after the size of the object. Another known sorting solution is to allow a bulk stream of objects to drop over a ledge, similarly to a waterfall. A camera or a set of cameras detect properties of the objects during the object’s fall, and an ejector unit is arranged to eject objects having certain detected properties in the fall. A downside of this solution is that it is rather imprecise, even with an optimized fluid jet stream, since for each ejection also several neighboring objects, e.g. up to 8 to 12 at full capacity, are ejected together with the object having the certain property. A majority of the ejected object may thus not have the certain property triggering the ejection. At the same time, many objects which should not have been ejected will be ejected by this method. This has a detrimental impact on the throughput of the system as well as the capability and degree of precisely sorting out objects.

[0007] Yet another known sorting solution, overcoming a number of the problems associated with the drum and waterfall sorting solutions is a system wherein objects are conveyed along a guide plate with a number of channels, wherein each channel comprises an aperture associated with an object measurement unit for conducting an optical measurement associated with a property of the object, and another aperture associated with an ejector unit, arranged to eject the object conveyed on the corresponding channel. Such a system is described in WO2019054932. For this sorting solution to work optimal it is of importance that objects do not travel down the channels on top of each other, which is a risk as sorting systems wherein the rate of supply of objects to the sorting system is uneven. Uneven feed also risks shooting objects over the inlet edge, such that the velocity of the object becomes unpredictable or that objects are getting jammed in the rather narrow channels during high feed. Furthermore, there is a risk that objects becomes airborne and therefore provides poor measuring and characterization results. If objects are not properly distributed, there is also a risk that two objects are measured as one, and becomes sorted based on an average value. Alternatively, one of the objects are shot erroneously. The objects should not roll or skip, they should preferably slide for an optimal result.

[0008] Hence, an improved system for sorting out objects would be advantageous.

[0009] SUMMARY

[0010] Accordingly, the present invention preferably seeks to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solves at least the above mentioned problems by providing an object conveying system comprising; a guide plate extending in a longitudinal direction, said guide plate having at least one channel for conveying an object between a first end zone and a second end zone; at least one object measurement unit for conducting one or more measurements associated with a property of the object; at least one ejector unit arranged to eject the object; wherein an object feed device is arranged in the vicinity of the first end zone, said object feed device having a central axis, and the object feed device is arranged such that the central axis is positioned transversally in relation to the longitudinal direction of the guide plate.

[0011] Advantageous embodiments are envisioned in the dependent claims below.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] These and other aspects, features and advantages of which the invention is capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which

[0014] Fig. 1 is a schematic view of an object conveying system according to one embodiment of the present invention;

[0015] Fig. 2 is schematic view of channels according to one embodiment of the present invention;

[0016] Fig. 3 is a perspective view of a top part of an object conveying system according to one embodiment of the present invention;

[0017] Fig. 4 is a cross-sectional view of an object conveying system according to one embodiment of the present invention; and

[0018] Fig. 5 is a perspective view of a top part of an object conveying system according to one embodiment of the present invention.

[0019] DESCRIPTION

[0020] The following description is dedicated to an object conveying system, used to sort out objects having certain measured properties from a bulk of objects. Such objects may be organic or inorganic, such as e.g. grains, granules, lentils, nuts, tree nuts, beans, recyclables, minerals, metals, plastics, etc.

[0021] Figure 1 shows a perspective view of an object conveying system 10. The object conveying system 10 comprises guide plate 100. The guide plate 100 has a longitudinal extension L. The guide plate 100 has at least one channel 101 for conveying an object O between a first end zone 102 and second end zone 103 of the corresponding channel 101. Preferably, the at least one channel 101 is configured to convey the object O by gravity, or mechanically, for instance using a conveyor belt.

[0022] In Fig. 2 there is disclosed a schematic close up on a number of channels 101. However, it should be appreciated that any number of adjacently provided channels could be used. Each channel 101 comprises a first aperture 108 provided at a first longitudinal position thereof Pl.

[0023] An object measurement unit 200 is provided to conduct a measurement, such as an optical measurement associated with a property of the object O via the first aperture 108 when said object passes the first aperture 108 towards the second end 103. The measurement may alternatively be a magnetic measurement, an ultrasound measurement or a weight measurement associated with a property of the object O.

[0024] The first aperture 108 may optionally be provided with a mesh, grid, or transparent material, such as glass, adapted not to interfere with the measurement, preferably being an optical measurement, over the object O, such that the aperture 108 not necessarily is adapted in size to the size of the object, which in turn gives the opportunity to measure in the axial plane over the entire length of the object O.

[0025] At least one ejector unit 300 is arranged to eject the object conveyed on the corresponding channel 101 when reaching a corresponding second aperture 109 downstream of the first aperture 108 based on the measured property of the object and a timing signal corresponding to a conveying velocity, i.e. the relevant velocity for the movement of the object O towards its corresponding ejector unit 300, of the object being conveyed along the channel 101. When more than one fraction is to be separated from the bulk of objects, each channel 101 may be provided with more than one ejector aperture, such as 2, 3, 4, or 5, each additional aperture having its corresponding ejector unit 300 to separate a corresponding fraction, based on at least one property of the object O.

[0026] The second aperture 109 may be provided within the boundaries of each channel 101, as indicated in Fig. 2, or the ejector units may be provided downstream the second end zone 103 of each channel 101.

[0027] The timing signal may be arranged to activate any one of the corresponding ejector units, such as eject the corresponding object having the property being measured. In order to achieve this it is important to know when said object will pass said second aperture 109, such as to activate corresponding ejector unit 300 at the correct time to eject the object when the corresponding object reaches the second longitudinal position. The timing signal is thus corresponding to the conveying velocity of the object between the first aperture and the second longitudinal position. Preferably, the object conveying system 10 is operated at a constant predetermined velocity, and therefore the speed of the objects O is predetermined. In this way, the ejector unit 300 knows when it is time to eject an object. Alternatively, the time instant at which an ejector unit 300 should be activated may be calculated in different ways.

[0028] Here, the object measurement unit 200 may be arranged to optically detect the object O passing the first aperture 108 at an associated first time instant Tl, and the object O passing the second aperture 109 at an associated second time instant T2.

[0029] Alternatively or in combination the conveying velocity could be calculated by using measurements only from the first aperture 108. Here, the object measurement unit 200 is arranged to optically detect the object O passing the first aperture 108 at an associated first time instant Tl, and the object exiting the first aperture 108 at an associated second time instant T2. Using that distance=velocity*time, the conveying velocity of the object may be calculated utilizing a time duration, defined by the difference between the second time instant T2 and the first time instant Tl, and a known size of the first aperture 108. Here it should be appreciated that the object measurement unit 200 could detect the first time instant Tl when the front end of the object passes the upstream end of the first aperture 108 and the second time instant T2 when the front end of the object O reaches the downstream end of the first aperture 108.

[0030] As seen with reference to Fig. 2, each channel 101 may comprise a longitudinally extending base 110 and a pair of sidewalls 111, 112 arranged along either lateral side of the base 110 for limiting the movement of the object O in a lateral direction when being conveyed longitudinally along the base 110. This lateral confinement drastically improves calculations and moreover, aligns the respective object O to the downstream second longitudinal position at which the object will optionally be ejected by the ejector unit 300 by the use of a fluid jet stream through the second aperture 109. The first aperture 108 and / or second aperture 109 may be provided straight through the base 101. Each channel 101 may have a width dimensioned to accommodate a single object.

[0031] Although the channels in the drawings have a rectangular shape, other shapes are also possible. For example, the side walls 111, 112 need not be parallel, so as to self-center the object O in the channel 101. In such case, at least one of the side walls 111, 112, such as both side walls 111, 112, are inclined in relation to a vertical, in use, or in relation to a general normal to the guide plate 100. The ejector unit 300 may be a fluid jet stream unit, an electromagnetically activated membrane, or piezoelectric punch / thrust.

[0032] The object conveying system 10 may comprise a control unit operatively coupled to the ejector unit 300 and / or object measurement unit 200. Hence, the control unit may be arranged to activate each ejector unit 300 based on the timing signal being associated with the calculated time for each object that has been positively identified to have the property measured by the object measurement unit 200. Accordingly, the control unit may be arranged to eject a particular object O based on information of said object O being obtained from the object measuring unit 200.

[0033] In Fig. 3 the upper part of the object conveying system 10 is disclosed. In the vicinity of the first end zone 102 an object feed device 400 is arranged. The object feed device 400 has a central axis A. The object feed device 400 is arranged such that the central axis A is positioned transversally in relation to the longitudinal direction L of the guide plate 100. The object feed device 400 is rotatable around the central axis A to allow the object O onto the guide plate 100. The object feed device 400 may also be a screen that is configured to move perpendicular to the central axis A to close or open the flow of objects O passed the object feed device 400. In Fig. 3, the object feed device 400 is an object feed roller 400A.

[0034] The guide plate 100 has a first curvature 104, as disclosed in Fig. 4, being a longitudinal cross-sectional view of the object conveying system 10, at the first end zone 102. The first curvature 104 curves around the central axis A of the object feed roller 400 A. The relationship between the curve of the first curvature 104 and the central axis A does not need to be constant. Rather, the curve of the first curvature 104 has a focal point up-streams the object feed roller 400 A, such that the object feed roller 400A and its central axis is positioned such that the distance between the first curvature 104 and the central axis A decreases when moving down-streams the guide plate 100.

[0035] The first end zone 102 has a second curvature 105 down-streams the object feed roller 400A. The second curvature 105 curves around a back axis B. The back axis B is parallel with the central axis A of the object feed roller 400A. The back axis B is on the other side of the guide plate 100, i.e. the back side of the guide plate 100, compared to the central axis A of the object feed roller 400A.

[0036] The first curvature 104 transition into the second curvature 105, to form an S- shape, such that there is no ledge or planar section between the first curvature 104 and the second curvature 105. At the transition point between the first curvature 104 and the second curvature 105 the distance from the central axis A of the object feed roller 400A to the guide plate 100 is substantially at its smallest.

[0037] This configuration of the object conveying system 10 allows for moving the bulk of objects O into a position where it exceeds the angle of repose, without pushing the objects O onto the guide plate 100. This avoids the objects O from being shot over the edge with too much speed, nor to get squeezed or crushed by the object feed roller 400 A. The S-shape of the first end zone 102 allows for avoiding to have objects O in the upper part, i.e. the first end zone 102, when the object conveying system 10 stops receiving objects. There is no point at which an object O can be at an angle where it is allowed to rest. Furthermore, the arrangement with an object feed roller 400 A allows for stacking a plurality of guide plates 100 on top of each other, without consuming additional space, and without adding vibrations etc.

[0038] Up-streams the first curvature 104 of the guide plate 100 may have a planar retardation part 106. At the retardation part 106 and the first curvature 104, objects O will be retarded / choked by the object feed roller 400A. The retardation part 106 of the guide plate 100 may be parallel with an object flow part 107 of the guide plate 100, said object flow part 107 being located down-streams the object feed roller 400 A. In this way the object conveying system 10 may operate at a constant supply of objects irrespective of if the supply of objects O to the object conveying system is irregular and changes over time.

[0039] The object feed roller 400 A may be provided with a surface friction pattern. For example, the object feed roller 400A may be provided with a corrugated pattern. The corrugations of such corrugated pattern may extend substantially parallel to the central axis A. In this way, objects may be fed synchronously into the channels 101.

[0040] The object feed device 400 is motor driven to feed objects into the channels 101. Hence, when the object feed device 400 is an object feed roller 400A, it is not the weight of the objects that make the object feed roller 400 A to rotate, but instead the rotation of the object feed roller 400A is controlled to feed objects O in a controlled manner into the channels 101.

[0041] The object feed roller 400 A provides an object feed device 400 having a very precise feeding velocity of the objects O. Further, the object feed roller 400 A may vary the feeding velocity within a broad range.

[0042] Fig. 5 shows an object feed device 400 in the form of an object feed gate 400B. The object feed gate 400B may be motor driven to feed objects O into the channels 101 and / or it may be set at a force resistance value, such that the weight of the bulk of objects opens the object feed gate 400B. The object feed gate 400B may also be manually driven. Hence, the object feed gate 400B will operate between an opened state, where objects O are fed into the channels 101, and a closed state, where objects O are maintained in the area of the first curvature 104. The feed gate 400B may be operated to be opened to different degrees to regulate the flow of objects through the feed gate 400B. Hence, the feed gate 400B may be opened gradually from the closed state into a fully opened state. The flow of objects through the feed gate 400B may be measured down streams the feed gate 400B and may be fed back to the feed gate 400B to adjust the degree of openness. The object feed gate 400B provides an object feed device 400 with an improved sealing / closure function. The feed gate 400B may also be provided with a closure return spring, such that the feed gate 400B closes the flow of objects through the feed gate 400B if for example a power failure to the drive motor occurs.

[0043] In Fig. 5, the upper part of the object conveying system 10 is disclosed. The object feed gate 400B is arranged in the vicinity of the first end zone 102. The object feed gate 400B has a central axis A. The object feed gate 400B is arranged such that the central axis A is positioned transversally in relation to the longitudinal direction L of the guide plate 100.

[0044] Similarly to what is shown in Fig. 4, the guide plate 100 has a first curvature 104 at the first end zone 102. The first curvature 104 curves around the central axis A of the object feed gate 400B. The relationship between the curve of the first curvature 104 and the central axis A does not need to be constant. Rather, the curve of the first curvature 104 has a focal point up-streams the object feed gate 400B, such that the object feed gate 400B and its central axis A is positioned such that the distance between the first curvature 104 and the central axis A decreases when moving down-streams the guide plate 100.

[0045] The first end zone 102 has a second curvature 105 down-streams the object feed gate 400B. The second curvature 105 curves around a back axis B. The back axis B is parallel with the central axis A of the object feed gate 400B. The back axis B is on the other side of the guide plate 100, i.e. the backside of the guide plate 100, compared to the central axis A of the object feed gate 400B.

[0046] The object feed gate 400B comprises main body 410 mounted on and engaging a core 412. The core 412 extends along the central axis A. The main body 410 further comprises a flange 415 extending radially, outwardly from the main body 410. The first curvature 104 transition into the second curvature 105, to form an S-shape, such that there is no ledge or planar section between the first curvature 104 and the second curvature 105. The flange 415 extends towards the transition point between the first curvature 104 and the second curvature 105.

[0047] To open the object feed gate 400B, the object feed gate 400B is rotated about the central axis A such that the flange 415 allows objects O to pass from the area of the first curvature 104 to the second curvature 105. The objects O are allowed to be conveyed in the channels 101, as shown in Fig. 2.

[0048] This configuration of the object conveying system 10 allows for a decreased energy consumption. Further, the object feed gate 400B is simple to regulate and is gentle on the objects O. Also, the object feed gate 400B is less sensitive for larger objects. If a larger object is trapped at the object feed gate 400B it will only cover the channel 101 where the object is present.

[0049] Although the present invention has been described above with reference to specific illustrative embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and other embodiments than the specific embodiments described above are equally possible within the scope of these appended claims.

[0050] In the claims, the term “comprises / comprising” does not exclude the presence of other elements or steps. Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and / or advantageous. In addition, singular references do not exclude a plurality. The terms “a”, “an”, “first”, “second” etc. do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.

Claims

CLAIMS1. An object conveying system (10) comprising; a guide plate (100) extending in a longitudinal direction (L), said guide plate (100) having at least one channel (101) for conveying an object (O) between a first end zone (102) and a second end zone (103); at least one object measurement unit (200) for conducting one or more measurements associated with a property of the object (O); at least one ejector unit (300) arranged to eject the object (O); wherein an object feed device (400) is arranged in the vicinity of the first end zone (102), said object feed device (400) having a central axis (A), and the object feed device (400) is arranged such that the central axis (A) is positioned transversally in relation to the longitudinal direction (L) of the guide plate (100), said object feed device (400) being configured to regulate the flow of the object (O) onto the guide plate (100).

2. The object conveying system (10) according to claim 1, said object feed device (400) being rotatable around the central axis (A) to allow the object (O) onto the guide plate (100).

3. The object conveying system (10) according to claim 1 or 2, wherein the at least one channel (101) is configured to convey the object (O) by gravity or mechanically, such as with a conveyor belt.

4. The object conveying system (10) according to any one of the preceding claims, wherein the at least one object measurement unit (200) is configured to conduct an optical measurement associated with a property of the object (O).

5. The object conveying system (10) according to any one of the preceding claims, wherein the first end zone (102) having a first curvature (104) around the central axis (A).

6. The object conveying system (10) according to claim 5, wherein the first end zone (102) having a second curvature (105) around a back axis (B), said back axis (B) being parallel with central axis (A) and being positioned on the other side of the guide plate (100) compared to the central axis (A).

7. The object conveying system (10) according to claim 6, wherein an object retardation part (106) of the first end zone (102) up-streams from the first curvature (104) is parallel to an object flow part (107) of the first end zone (102) down-streams the second curvature (105).

8. The object conveying system (10) according to any of the preceding claims, wherein the object feed device (400) is motor driven to feed objects (O) into the at least one channel (101).

9. The object conveying system (10) according to any of the preceding claims, wherein the object measurement unit (200) is arranged in association with a first aperture (108).

10. The object conveying system (10) according to any of the preceding claims, wherein the ejector unit (300) is arranged in association with a second aperture (109) down-streams the first aperture (108).

11. The object conveying system (10) according to any of the preceding claims, wherein the guide plate (100) having a plurality of channels (101), wherein each channel (101) comprises a longitudinally extending base (110) and a pair of sidewalls (111, 112) arranged along either of the base (100) for limiting the movement of the object (O) in a lateral direction when being conveyed longitudinally along the base (110), and that each channel (101) has an associated object measurement unit (200) and an associated ejector unit (300).

12. The object conveying system (10) according to claim 11, wherein the first aperture (108) and / or second aperture (109) is provided through the base (110).

13. The object conveying system (10) according to any one of the previous claims, wherein each channel (101) has a width dimensioned to accommodate a single object (O).

14. The object conveying system (10) according to any of the previous claims, further comprising a control unit arranged to control the operation of the ejector unit (300) and / or object measurement unit (200).

15. The object conveying system (10) according to claim 14, wherein the control unit is further arranged to eject a particular object based on information of said object being obtained from the object measuring unit (200).

16. The object conveying system (10) according to any of the previous claims, wherein the object feed device (400) is an object feed roller (400 A).

17. The object conveying system (10) according to any of the preceding claims, wherein the object feed roller (400A) is provided with a surface friction pattern on its outer surface.

18. The object conveying system (10) according to any one of claims 1 to 17, wherein the object feed device (400) is an object feed gate (400B).

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