The present invention relates to a sorting apparatus and method and more specifically to a sorting apparatus and method for separating articles in a product stream using a mechanical diverter responsive to a machine vision system. The present invention also includes a combination of a sorting apparatus that uses an air ejector for foreign material removal and a mechanical diverter for redirecting undesirable articles from a product stream.
Sorting Methods and machines have been known and practiced for many years in the production of goods including comestible articles. The machines found in the art include types that utilize reflecting electromagnetic radiation in the form of light to determine the optical reflective characteristics of the articles in the product stream using color as a determinant followed by an ejector to successfully remove offending articles. A notable example of such a sorter is the High Speed Mass Flow Sorting Apparatus for Optically Inspection and Sorting Bulk Food Products as shown in U.S. Pat. No. 5,887,073 assigned to Key Technology, Inc.
Successful removal of offending or undesirable articles has been practiced to varying degrees of efficiency using several different approaches including air ejection and mechanical diversion. Experience has shown that air ejection techniques are suitable for a wide range of article types, but is best applied for smaller, less dense articles that can be easily influenced by a jet of fluid. Examples of articles suitable for air ejection include peas, corn, potato strips, potato crisps, and foreign material. Air ejection as commonly practiced utilizes a plurality of electrically controlled valves that are individually controlled by a machine vision system, and targeted toward offending articles in a product stream. Thus, the offending articles are dislodged from their course of travel and caused to take an alternate path, removing them from the product stream.
Alternatively, mechanical diversion is similarly suitable for a wide range of articles, however, it is best applied for larger articles that are less susceptible to influence by a jet of fluid. Examples of articles suitable for mechanical diversion include oranges, grape fruit, onions, and potatoes. Mechanical diverters are known in the art to require more frequent maintenance than air ejectors. In addition, mechanical diverters are more prone to bruise undesirable articles during diversion.
An example of a sorter using a mechanical diversion technique is found in U.S. Pat. No. 5,979,667 where a rigid paddle is taught that selectively strikes articles from the product stream forcing them onto another path. In this reference, a pulsed light sensor interrogates a product stream of articles such as tomatoes. A color comparator utilizes information from the pulsed light sensor to identify undesirable articles. A pneumatically operated and electrically controlled rigid paddle is positioned so that undesirable articles are expelled from the product stream by striking them during their path to send them to an alternate location. The reference also teaches the option of reversing the logic so that the rigid paddle is used to divert acceptable articles. Unfortunately, the striking action of the rigid paddle upon the article during its course of travel has the potential to bruise the articles, reducing their value.
Another example is found in U.S. Pat. No. 5,509,537 where a flexible finger is used to selectively strike undesirable articles from the product stream. Here, the flexible finger is presented as an alternative to the rigid paddle described above, citing an improvement in maintenance over the prior art. One might expect that the striking flexible finger might decrease adverse impact to the article. However, such a flexible finger would decrease the accuracy of the ejection operation by nature of its flexibility.
The present invention overcomes this and other limitation of the prior art. For instance, none of these examples, or other examples in the art teach a sorter that utilizes a mechanical diverter having a concave shape that can gently redirect undesirable articles to another path for further, processing. In addition, the art does not teach the combination of utilizing both air ejection and mechanical diversion in a single sorter.
One aspect of the invention is a sorting apparatus for separating articles in a product stream, including an endless belt conveyor configured to launch articles from the product stream in a first trajectory, an inspection station coupled to the product stream and operable to provide a routing signal based on inspection of the product stream, and a diverter comprising a launching block having a concave surface, and located in downstream relation to the inspection station, and controlled by the routing signal, and wherein the diverter has a retracted position where articles extend their travel in the first trajectory, and an extended position where articles interact with the diverter in a gliding manner along the concave surface to effectively launch the articles into a second trajectory.
Another aspect of the invention is a sorting apparatus for separating articles in a product stream, including a conveying means to transport and launch the articles in a product stream in a first trajectory, an inspection means coupled to the product stream to provide a first and second routing signal based on inspection of the product stream, and a diverter means having a concave member, and controlled by the first and second routing signals and located in downstream relation to the inspection station to pass articles in the first trajectory in response to the first routing signal, and to urge articles to assume a second trajectory in response to the second routing signal by urging the articles to glide along the diverter so that the articles are effectively launched into a second trajectory.
Yet another aspect of the invention is a sorting apparatus for separating articles in a product stream having acceptable articles, unacceptable articles, and foreign material, including an endless belt conveyor configured to launch the product stream in a first trajectory, an inspection station coupled to the product stream and operable to provide a plurality of routing signals based on inspection of the product stream, a first air ejection station located in downstream relation to the inspection station, and controlled by a first portion of the plurality of routing signals, and configured to expel the foreign material from the product stream product stream in a second trajectory, and a concave shaped diverter located in downstream relation to the inspection station that is controlled by a second portion of the plurality of routing signals, and operable to launch undesirable articles from the product stream so that they become separated from the desirable articles in the product stream.
And yet another aspect of the invention is a method of separating articles from a product stream into a plurality of routes, including conveying the product stream, launching the product stream in a first trajectory, inspecting the product stream, providing a first and second routing signal based on inspection of the product stream, providing a diverter having a concave surface that is responsive to the first and second routing signals so that the diverter is configured in a retracted position in response to the first routing signal, and configured in an extended position in response to the second routing signal, passing articles from the product stream so that they continue to travel in the first trajectory when the diverter is configured in the retracted position, and launching articles from the product stream by urging the articles to glide along a portion of a surface of the diverter so that they assume a second trajectory when the diverter is configured in the extended position.
These and other aspects of the present invention will be described in greater detail hereinafter.
Preferred embodiments of the invention are described below with reference to the following accompanying drawings.
a is a perspective view of a launching block from the diverter.
b is an inverted perspective view of a launching block from the diverter.
This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8).
Referring now to
A stream of articles or incoming product stream 12 is introduced at an infeed end of the sorter 10. In practice, the product stream 12 may be composed of any article of manufacture or production, and often includes both desirable articles which meet the specification of quality and undesirable articles which fall outside the specification of quality. Further, the incoming product stream 12 may contain other materials which have a different nature than the articles and will herein be referred to as foreign material. The product stream 12 is composed of individual articles traveling in a direction generally depicted by the flow arrow 14. The product stream 12 may include individual articles that are moving in concert at a generally uniform speed and traveling in the product flow direction 14.
Articles in the product stream 12 are introduced to an endless belt conveyor 16 that is integrated into the sorter 10 for transporting the articles through the sorter 10. The conveyor 16 includes an endless belt selected to provide a sufficient force of friction for stabilizing articles in the product stream 12 as they are transported in the flow direction 14.
The sorter 10 includes a user interface 18 that enables an operator (not shown) to observe and control various operational aspects of the sorter 10. From the user interface 18, an operator can view representations of the articles in the product stream 12 as they are processed in the sorter 10. In addition, the user interface 18 provides a means for the operator to configure the operation of the sorter 10 to enable the sorter to make a determination between acceptable articles, undesirable articles, and foreign material.
Articles in the product stream 12 are transported along a path to the end of the conveyor 16 where they are launched in a trajectory. The product stream 12 is composed of articles that are scattered across both a width and length of the conveyor 16, and are illustrated in a single-file manner in
A routing assembly 22 is positioned in downstream relation to the inspection station 20 and is configured to respond to directives provided by the inspection station 20. The routing assembly 22 includes a plurality of active diverters that are capable to urge articles and foreign material in the product stream 12 to follow predefined paths. One such path is a foreign material path 24 which is established as a path for foreign material in the product stream 12 to follow. A second path is an acceptable article path 26 provided for acceptable articles in the product stream 12 to follow. Another such path is an unacceptable article path 28 maintained for unacceptable articles in the product stream 12.
Now referring to
The inspection station 20 includes a first camera 36 positioned to view the product stream 12 as it is transported by the endless belt conveyor 16. A second camera 38 is positioned to provide a downward looking view of the product stream 12 after it has been launched by the endless belt conveyor 16. A third camera 40 is positioned to provide an upward looking view of the product stream 12 and after it has been launched by the endless belt conveyor 16. It should be understood that the inspection station 20 may include fewer or a greater number of cameras or other types of sensors including photodiodes, photomultiplier tubes, or other types of imaging devices known in the art without departing from the scope of this invention.
The inspection station 20 also includes a sorting processor 42 that is connected to each of the cameras 36, 38, and 40 and is operable to process signals provided by each of the cameras to provide data indicative of physical characteristics of articles and foreign material in the product stream 12. The sorting processor 42 compares these signals with guidance provided by an operator (via the user interface 18 (
The routing assembly 22 includes an ejector 46 positioned above and directed toward the product stream 12 and is connected to one of the routing signals 44. The ejector 42 is composed of a plurality of solenoid valves and jets arranged across the width of the sorter 10 that operate to direct a pulse of air toward the product stream 12 to dislodge from the product stream 12 an article or foreign material targeted by the sorting processor in response to the routing signal 44. Each of the plurality of jets in the ejector 42 is associated with one virtual lane 21 (
The routing assembly 22 also includes a mechanical diverter assembly 50 that is operably connected to the routing signals 44 composed of commands provided by the sorting processor 42. The diverter assembly 50 is positioned beneath the product stream 12 and in a manner so that it can interact with the product stream 12 to efficiently route articles in the product stream 12 to a lower slide 52 and an upper slide 54. An upper guide 56 is provided and positioned above the upper slide 54 whose operation will be discussed in further detail below.
In a preferred embodiment, acceptable articles 30 are routed through the region defined between the lower slide 52 and the upper slide 54 and follow the normal trajectory 100 until encountering the lower slide 52. Also in a preferred embodiment, unacceptable articles 32 are routed through the region defined between the upper slide 54 and the upper guide 56 and follow either a gentle trajectory 106 or an aggressive trajectory 108. The diverter assembly 50 is shown in a retracted position 102 in
Now referring to
A plurality of actuators 66 are connected in fluid transmission relation to the plurality of solenoid valves in the valve assembly 64 and are each borne by the mounting frame 62 on a plurality of actuator pivot pins 68. Each actuator has a rod 70 operable to positionally respond to fluid pressure. A bracket 72 is fastened to each rod 70.
A plurality of launching blocks 76 are pivotally positioned in juxtaposed relation between a plurality of pivot pins 70 that are located on the mounting frame 62, and between the bracket 72. A block pin 74 retains the launching block 76 to the bracket 72. Each launching block 76 is fastened in such a manner that an extension of the rod 70 of the actuator 66 effectively raises a portion of the launching block 76 enabling a controllable interaction with the product stream 12 which is effective in routing articles in response to commands from the sorting processor 42 (
In a preferred embodiment, the actuator 66 is a pneumatic cylinder having sufficient piston area to accurately position the launching block 76 in response to commands from the sorting processor 42.
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The calculation step 122 is followed by a distance, threshold decision 124 where the distance is compared with a predefined minimum distance value referred herein as dmin. If the distance threshold decision 124 is true, then a type decision 126 is made based on review of the tag of each of An and An-1. If the type decision 126 is true, then a delay step 128 is performed followed by an aggressive reject step 130.
If the distance threshold decision 124 or the type decision 126 is false, then a reject decision 132 is made. If the reject decision 132 is true, then a gentle reject step 134 is performed. If the reject decision 132 is false, then a pass step 136 is performed.
The operation of the present invention is believed to be readily apparent and is briefly summarized in the paragraphs which follow.
In operation, and referring to
Cameras 36, 38, and 40 provide a means to measure physical characteristics of objects in the product stream 12, and this measurement data is provided to the sorting processor 20 where it is compared with the sorting parameters discussed above to render a series of sorting decisions which are manifested as the plurality of routing signals 44.
Now referring to
Also, in a preferred embodiment, a substantial portion of acceptable articles 30 are detected and tagged by the sorting processor 42 by the diverter control routine 110 in the tag step 120 as ACCEPT and allowed to travel in the normal trajectory 100, uninfluenced by the ejector 46. Yet further, the sorting processor 42 in the pass step 136 provides routing signals 44 to the diverter assembly 50 to move or maintain it in a retracted position as shown in
Now referring to
Now, if An-1 is ACCEPT and An is REJECT then the type decision 126 is true and the delay step 128 will be performed. Here, the routing signal 44 will be delayed, holding the diverter assembly 50 in the retracted position 102 to allow An-1 to pass. Then, after the delay step 128 is complete, the aggressive step 130 is performed, so the diverter assembly 50 is moved to launch An in the aggressive trajectory 108 because the sorting processor 42 issues a routing signal 44 which causes the valve assembly 64 to port fluid to the actuator 66 to cause the rod 70 to control the position of the launching block 76. In this action, the unacceptable article 32 encounters the launching block 76 proximate to the contact surface 88 as it is moved from the retracted position 102 to the extended position 104, imparting an upward force on the article, and causing it to deviate from the normal trajectory 100, and follow a path approximately similar to the aggressive trajectory 108. The unacceptable article 32 may encounter the upper guide 56 and/or the upper slide 54 where it is discharged for further processing. This aspect of the operation of the sorter 10 enables efficient diversion of unacceptable articles 32 that are in the proximity of acceptable articles 30 in the same or adjacent virtual lanes 21, allowing the acceptable articles 30 to pass in the normal trajectory 100.
Alternatively, if the type decision 126 is false or if the distance threshold decision 124 is true, then the reject decision 132 is performed by the sorting processor 42. If the reject decision 132 is true, meaning that An is tagged as REJECT, then the diverter assembly 50 is moved to the extended position 104 in a manner similar to that discussed above. If the diverter assembly 50 was already in the extended position 104, then it is maintained in that position. In either case, the unacceptable article 32 will encounter the launching block 76 when it is already at the extended position 104, so that it is encounters the contact surface 88. Here it will slide on the contact surface 88, traveling to the launching surface 90 which will redirect the motion, providing a smooth translation so that it is launched in the gentle trajectory 108, having minimal upward motion, and traveling until it encounters the upper slide where it is discharged for further processing.
In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and describe, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.