Patent ID: 12246357

It will be noted that throughout the appended drawings, like features are identified by like reference numerals.

DETAILED DESCRIPTION

Referring toFIG.1, there is shown a system10for sorting materials undergoing a movement, such as on a running conveyor. The system10according to an embodiment of the invention comprises a sorting apparatus20and a vacuum apparatus30in combination therewith. The sorting apparatus20comprises a conveyor210on which the materials (comprising individual items to be sorted) are transported, or any other mechanism by which the materials to be sorted are being moved for the purpose of performing selective picking during said movement, the movement permitting a high frequency for this selective picking. The sorting apparatus20is adapted to perform real-time identification of the items transported thereon in view of the selective picking.

A handling tool220, or head, is provided and is used to grab and handle selected large items on the conveyor210, or alternatively to suck up selected small items away from the conveyor210, depending on a real-time identification made immediately before the grabbing or the sucking action. The handling tool220is robotized, so that the handling tool220is directed right above the expected location of the selected items on the moving conveyor210(or any other moving mechanism), and the handling tool220can grab the item for removal from the conveyor210and displacement to another location (e.g., into a dedicated container, onto another conveyor, onto a specific location on the floor, etc.).

The sorting apparatus20comprises a mechanism to displace the handling tool220by robotized translation of the handling tool220over the conveyor210, for example arms212, which are shown inFIG.2. These arms212are expected to extend from a gantry or another static location above the conveyor, and are robotized be able to translate the handling tool220at the location where the items to be grabbed or sucked up are to be located at the end of the movement of the handling tool220(i.e., the time taken for the robotized translation and the movement of the item over the conveyor210during this time interval should be taken into account when the robotized movement is instructed). Items are identified using appropriate optical equipment214, which can comprise cameras using image recognition, or other tools involving spectrometry (i.e., with a light source where the reflected light is analyzed) and the like to identify the nature of the items to grab or suck up, in particular the nature of the object (to decide whether to act on it or not) and the position where the handling tool220should be displaced to act on it. The result is that a given item to remove will be either grabbed or sucked up, depending on its size relative to the diameter of the tubing, or not acted upon depending on the nature of the item, as described further below.

The device which controls the arms212and which receives data from the optical equipment214is generically called the sorting robot215, which can comprise a controller300for the system10, or be operatively connected to such a controller300, which receives and treats data to perform the tasks in the system10.

According to an embodiment of the invention, the handling tool220comprises a vacuum tube end222. Such a vacuum tube end222for the handling tool220is advantageous to provide a double functionality of either grabbing large items by suction, thereby acting like a suction cup, or sucking up small items away to perform vacuum cleaning. To this end, there is provided a vacuum tubing290, which extends from the handling tool220, where it has its vacuum entry point, to a decanter310, where it has its exit point. The vacuum tubing290performs the vacuum cleaning by removal of small items through the tubing, captured by the low pressure which draw them away and moves them through the vacuum tubing290toward the source of vacuum, and also performs the static suction by providing a tubing where a vacuum is made when the end (vacuum entry point) is obstructed by the large item to be sucked the large item being statically held there by suction.

In that particular case, the handling tool220is well adapted to vacuum clean (i.e., remove) the small items among the materials on the conveyor210. The implication is that small items can be identified, so that the handling tool220is directed (i.e., instructed and moved by the controller) right above the expected location of these items on the moving conveyor210(i.e., expected location by the end of the movement of the handling tool220), and the vacuum will suck up the small items away from the conveyor210, using the vacuum tubing290, to remove such small items from the conveyor210. The assumption here is that small items usually need to be removed as they are either valuable materials that need to be collected, undesirable debris that need to be removed, or materials that need to be put in a single place for any other reason, whether the materials being sorted are for recycling, construction, or other industrial processes. The expression “small items” may also refer to items which are not necessarily small, but are flexible or deformable such as to be suckable by the tubing. An example of such deformable or flexible items that fit inside the diameter of the tubing290can include consumer plastic bags.

FIG.5illustrates the materials on the conveyor210, including small and large items with a differentiated treatment (i.e., selective sorting).

According to an embodiment, and as shown inFIG.1and, more clearly, inFIG.3, the decanter310is a cyclonic decanter, which uses a rotary movement of the volume of air containing particles in suspension therein to filter said particles (i.e., the small items) from said volume of air by having them fall down into the container of the decanter310, while leaving the cleaned volume of air flow upwardly. The decanter310, when embodied as a cyclonic decanter, is typically a single container with an upper portion shaped as a cone in which the entering air flows in a tangential direction along the conical surface to separate particles (which fall down) and air (which flows up). After a continuous use of the system10, it should be expected that the decanter310fills up with the small items or particles accumulating therein.

Considering that the vacuum tube end222is upstream, there is defined another location downstream of the decanter310, a vacuum fan motor330(at the most downstream location in the path) that creates the necessary depression (pressure gradient) between itself and the decanter. Tubing390, extending between the decanter310and the vacuum fan motor330, connects them to perform the vacuum function by significantly decreasing the pressure in the decanter310and by keeping it low during operation. It should however be noted that the vacuum fan motor330that creates the necessary depression can be located elsewhere in the system10, for example within the tubing290(therefore, upstream of the decanter310or of any other item depository), as long as the sucked items can keep moving into the tubing290, for example using their momentum to keep moving past the vacuum fan motor330toward the decanter310, or fall within the tubing290under the force of gravity for example.

In order to achieve the double function of grabbing large items by static suction at the tube end and sucking up small items through the lumen of the tubing for vacuum cleaning, the depression created by the vacuum fan motor330(acting as a source of depression for the vacuum function) should be in the order of 40 inches of water or above, such as between 40 and 80 inches of water, preferably between 50 and 80 inches of water, and more preferably about 70 inches of water. An inch of water is the typical unit measurement in this field and it is equivalent to 248.84 Pa.

The vacuum tube end222is expected to be the end of a tube and therefore is expected to have a substantially circular opening. The diameter of this circular opening should be chosen to fit the desired threshold which defines which items are being grabbed and which items are being sucked up, and therefore depends on the application. Such a diameter can range between 0.5″ to 8″, for example about 2″. Items larger than this diameter or threshold are expected to be grabbed, while those smaller are expected to be sucked up through the tubing290, downstream toward the decanter310.

After a significant period of time of operating the system10, the decanter310will slowly fill up and the system10will become less efficient. In a typical work flow, the system10would need to be stopped completely to empty the decanter and clean it. This is a normal maintenance task, but it implies stopping the apparatus, which is not efficient.

According to an embodiment of the invention, there is provided a cleaning tool and method of operation thereof which allows emptying and purging the decanter310and avoiding turning the system10off. A compressed air source320is provided. The compressed air source320connects to a compressed air injection point370in the vacuum tubing390.

According to an embodiment of the invention, the compressed air injection point370is located between the vacuum fan motor330and the decanter310. The injection point370can otherwise be located at other places in the system10as long as the result is a significant decrease in the depression that is measured at the vacuum tube end222.

According to another exemplary embodiment, the injection point370can be replaced by a valve that shuts the tubing to effectively cease the depression from reaching the vacuum tube end222.

A valve340is located between the compressed air source320and the compressed air injection point370to act as a logical gate which lets compressed air into the tubing390to perform the purge. The valve is controlled by a controller300, such as the computer controlling the system10, which instructs the valve340to open when the purge is to be performed.

This purge can be performed periodically according to some rules. For example, it can be performed after a definite period of time operating the system10, or after a given number of items sucked up through the handling tool220, or after a given volume of material that was sucked up, or after a given height of small items in the decanter310, using in each case the appropriate detector.

The injection of compressed air has the effect of counter-balancing the vacuum from the vacuum fan motor330to reduce significantly or cancel the pressure gradient between the decanter310and the vacuum tube end222. Injected compressed air flows toward the vacuum fan motor330that created the depression and thereby stops the air flow from flowing toward the decanter310. The overall effect in the tubing290is to stop the vacuum at the level of the handling tool220and to stop inflow of materials into the decanter310.

Once the injection has started, the controller300can instruct the opening of a trap door360below the decanter310, or any other suitable means for emptying the decanter310by timing this operation with the injection of compressed air (i.e., the opening of the trap is simultaneous with the injection of compressed air which momentarily stops the vacuum mode of operation of the apparatus). This can be performed in a few seconds, for example by maintaining the injection of compressed air in the tubing for a given period of time between 2 and 4 seconds. During this time, the injection of compressed air in the tubing under vacuum operation reduces the pressure gradient, below a threshold where small items cannot be sucked up anymore, and thereby stops the flow of air and small items into the decanter310. The injection and its effect is almost instantaneous and this is why the purge can be performed so fast and easily without having to stop and restart the vacuum fan motor330, which would take longer to do. Once this is done, the trap is closed again and the purged decanted is ready for operation again. The controller300can therefore instructs the valve340to close to stop injection of compressed air and restart the normal vacuum mode of the handling tool220.

Moreover, this injection of compressed air can advantageously clean the filter at the exit of the tubing/entry of the decanter310because the injected compressed air is directed toward the entry of the decanter310, that it reaches with high pressure and velocity against the normal flow direction (being normally from the decanter310to the vacuum fan motor330while the compressed air being injected within the same tubing travels to the decanter310) and can perform a mechanical action of cleaning the filter by flowing therethrough in the reverse direction.

In order to actuate the opening of the trap door360, there may be provided a pneumatic cylinder, a hydraulic cylinder, or any other type of servomotor which can actuate a hinge or a similar device that opens a door, as instructed by the controller in synchronicity with the injection of compressed air.

This process ensures that the purge of the decanter310is performed in about 3 seconds. This procedure is almost seamless and does not hamper the operation of the system10.

According to another embodiment, the decanter310can be replaced by a chopper-blower to separate the small items, or flexible items (e.g., plastic bags) from the air that has been drawn thereinto.

According to another embodiment, the decanter310can be replaced by, or comprise therein, a screw compactor to separate the small items, or flexible items from the air that has been drawn thereinto, or to compact or withdraw materials. An endless screw compactor inside the decanter310would therefore act as a purge system therefor, and can be operated continuously to provide a continuous purge.

According to another embodiment, the decanter310can have no bottom (i.e., no cyclonic decanter in the system10) such that the sucked up small items fall onto the floor at a dedicated location. This alternative embodiment removes the requirement of a trap and of the injection of compressed air. In that case, it is likely that the vacuum fan motor330that creates the necessary depression will be located upstream of that dedicated location. In this case, as already mentioned above, the sucked items should keep moving into the tubing290, for example using their momentum to keep moving past the vacuum fan motor330toward their final destination, or fall within the remaining parts of the tubing290under the force of gravity for example. This case in which there is no decanter, and having the vacuum fan motor330upstream of the final destination of the sucked items, can be referred to as an automatic, continuous purge system. Advantageously, there is no constrained limit on the volume of those items that can be captured (i.e., as large as the facility can allow, but not constrained by a container size).

According to an embodiment, there is provided another injection point270closer to the handling tool220, i.e., between the handling tool220and the decanter310. This compressed air, when injected, has the effect of cancelling the depression directly at the level of the handling tool220. This is useful to release a large item that was grabbed by the handling tool220using suction, the release being performed instantaneously as the compressed air is injected in tubing close to the handling tool.

As mentioned above with respect to the injection point370, a valve or any other suitable mechanism that shuts the tubing to effectively cease the depression from reaching the vacuum tube end222can be added between the decanter310and the injection point270, to reduce flow or, equivalently, pressure at the injection point270.

Indeed, when a large item is grabbed by the handling tool220, it is not sucked up away through the tubing290as described with respect to the small items. It is instead captured, under the effect of static suction provided by the pressure gradient, by the handling tool220, which can lift up the item as long as the depression generated by the vacuum fan motor is sufficient for the weight of the large item (and taking into account that the shape of the object may not fit perfectly the vacuum tube end222, as described below, in which case higher pressure gradients may be necessary to keep holding the large item). According to an embodiment, the tubing290comprises a flexible portion291which can adapt to the robotized movement of the handling tool220. Moreover, when a large item is grabbed, a larger depression (i.e., pressure difference) is temporarily created within the tubing290as the vacuum fan motor330keeps running while there is no more air inflow from the vacuum tube end222, and the handling tool220deforms and contracts on itself, which has the effect of naturally lifting the end of the handling tool220and the grabbed item altogether along with the deformation of the handling tool220as a consequent result of the pressure gradient buildup following the grabbing action. The handling tool220can therefore be provided advantageously with a resilient material forming a bellow, as shown inFIG.2, or any other shape the deforms such as to be contracted longitudinally. This lift movement brings the grabbed item up, away from the other materials on the conveyor, the handling tool220can therefore be translated horizontally to bring the item elsewhere. To release the large item, injection of air in the injection point270, for example immediately downstream of the flexible portion291, cancels the depression, thereby eliminating the suction by which the item is grabbed and effectively releasing it under gravity. To avoid the whole tubing290to undergo deformations, the tubing290can be rigid, but for the flexible portion close to the handling tool220, and the handling tool220should be deformable in longitudinal compression to undergo the contraction movement due to the pressure gradient buildup during grabbing. For a proper lift, the contraction of the bellow at the end of the tubing290should be at least as high as the height of the large objects on the conveyor for lateral displacement and release of the object being grabbed,

The depression ranges described above are chosen to be sufficient to provide the necessary suction airflow to be able to grab items which have an irregular surface. For example, items with a large surface are grabbed by having the vacuum tube end222enter in contact with the surface and form a suction grabber. If the surface is irregular, the contact may not be good, and air may still pass through interstices between the vacuum tube end222and the item's surface. Having a large depression in the vacuum system30ensures that the item will still be grabbed despite the imperfect contact of the vacuum tube end222with its surface. Otherwise, providing the vacuum tube end222with a resilient material such as rubber or an equivalent thereof may help in providing an efficient suction cup effect for grabbing.

The injection of compressed air at the injection point270further provides a mean for unclogging the tubing, should there be any materials stuck therein, especially close to the handling tool220, due to a misclassification of an item as being a small item where it should not have entered the tubing in the first place.

According to an embodiment, the injection points270or370comprise a specific internal shape of the tubing which ensures that the injection of compressed air is efficient to compensate for the depression and thereby cancel the vacuum. For example, the tube may be shaped as a sequence of two consecutive elbows (e.g., 45° elbows) in the tubing, creating an obstacle for the airflow in the tubing290or390, with the point of injection270or370being a nozzle ending at the center of the lumen of the tube between these elbows. This geometry improves the effectiveness of vacuum cancelation, whether for the release of the grabbed item at the handling tool220or for purging the decanter310.

According to an embodiment, the handling tool220, or head, can comprise more than one vacuum tube end222, for example two tube ends, one being for grabbing items and the other being for sucking items away. The tubing290can comprise a corresponding number of tubes, or the tube can split to form the more than one vacuum tube end222. In other words, if the moving the head comprises more than one end, the plurality of ends can have their vacuum generated by the same blower (i.e., the same vacuum fan motor330) or by a corresponding plurality of motors, or any combination. The pressure can be set to be the same in all ends of the head, or an be set at different pressures, which would imply a selective removal of small items and grabbing of large items depending on the size and weight, i.e., each tube end does not suck or grab the same things due to different pressures in their tubing (only a large depression can be used on heavier items). The controller300may then decide which tube end among the plurality is the most appropriate for a specific sucking or grabbing task to be performed. The robot215can move all the tube ends or, alternatively, different robots may be used for the plurality of tube ends.

FIG.4illustrates that the material on the conveyor210are selected or not. Those not selected remain on the conveyor. Those which are selected by the optical equipment214are classified as a large or small (or hard or flexible), and are grabbed or sucked accordingly, these operations being controlled by the sorting robot215. Sucking small or flexible items (or any other type which fits inside the tubing290or deforms to fit thereinto) results in them ending up in the decanter310or other free repository, and are purged. The purge can be operated manually by the operator, or automatically by the controller300. The purge can involve opening the decanter310using a door, or can instead involve having the vacuum fan motor330located upstream of the repository of small items such that the vacuum operation on those small items also includes a continuous and automatic purge. The purge system can therefore comprise either the trap door360along with the injection point370and other associated equipment, or it can relate to the arrangement (vacuum motor fan upstream of the final destination of the small items) that makes possible the continuous purge, or to any other device described herein such as an endless screw or a chopper-blower, for example.

FIG.6is a flowchart which summarizes the method for sorting materials and comprises the following steps.

Step610—conveying materials among which an item is to be sorted;

Step620—selecting the item for removal from the conveyed materials;

Step630—displacing a handling tool onto the item;

Step640—performing a vacuum at a vacuum tube end within the handling tool, thereby grabbing said item by suction if the item is larger than the vacuum tube end or sucking up the item through the vacuum tube end if the item is smaller than the vacuum tube end;

Step650—injecting air into the vacuum tube to pause the vacuum; and

Step660—purging the item sucked up through the vacuum tube.

While preferred embodiments have been described above and illustrated in the accompanying drawings, it will be evident to those skilled in the art that modifications may be made without departing from this disclosure. Such modifications are considered as possible variants comprised in the scope of the disclosure.