US 3612250 A
Description (OCR text may contain errors)
Inventors Gerald F. Thompson;
Francis J. Fitzgerald, both of Grand Rapids, Mich. App]. No. 25,945 Filed Apr. 6, 1970 Patented Oct. 12,1971 Assignee Rapistan Incorporated Grand Rapids, Mich.
RECIIRCIUILATION LIMIT SYSTEM FOR  References Cited UNITED STATES PATENTS 3,075,653 1/1963 Wales 198/38 X Primary Examiner- Edward A. Sroka Attorney-Price, Heneveld, Huizenga & Cooper ABSTRACT: A recirculation limit system particularly adapted for utilization in conjunction with recirculating conveyors which, conventionally, recirculate articles carrying a specific address code until such time as they can be diverted to the proper destination. ln accordance with the principles of this disclosure, the articles are permitted to recirculate past the various destination diversion gates two times and are then m diverted to a reject area. This is accomplished by placing a re- Elms m mg ject code on the containers or articles after their initial pass by US. Cl 1198/38 the destination diverters and then diverting them on to a reject int. Ci 365g 43/00 conveyor in accordance with the reject code if they are not Field of Search 198/38; diverted to a destination on their second. pass by the destina- 2l4/l l R; 209/74 tion diverters.
40 n l2 2m 23A 40 are 25B are 23c 2m 25D 5| 2? PICK! MG 1 AREA ADDRESS ADDREEB ADDRESS ADDRESS RE! ECT 4Q 40 CODE CQDE coca cope coca sausoa sensor: season SENSOR sensor:
22A 22B zac 22o 4o 2AA 24a 24: am
MARSHAUNG MARSHALlNG MAR$HALING MAWUKUNG as AREA A AREA B AREA C AREA D Rcraer 2n cope APPLtCATOR I nzrecr AREA RECHRCUILATIIQN LllMlT SYSTEM lFOlk CONVlEYUlRS BACKGROUND OF THE INVENTION This invention relates to recirculating conveyor systems and, more particularly, to such systems embodying a novel means for limiting the number of times a particular article may be recirculated within the system prior to being diverted to a reject area.
It is conventional in the material-handling field to provide a recirculating conveyor system whereupon articles are conveyed between their initial introduction into a given conveyor system and their diversion therefrom to a specific destination. The destination of the article, ordinarily, is coded in some fashion either upon the article itself or upon a carrier therefor and specific destination diversion means activated in accordance with that code as the articles are recirculated. If the articles are not diverted during their initial pass by the diversion means associated with their particular destination, theoretically, they merely recirculate until such time as the proper diversion is accomplished, the recirculation feature compensating, of course, for momentary malfunctions of the diversion means, destinations which are filled to capacity and the like.
A marked tendency has existed in the past for the recirculating conveyor in some types of systems to become virtually filled with constantly recirculating articles, thus preventing the introduction of new articles thereonto. This tendency has been prompted, primarily, either by slightly improper address codes on the article or prolonged malfunctions at one or more of the destination diversion means. In such a situation, as will be readily apparent to those skilled in the art, the improperly addressed or coded article or the article destined for a particular malfunctioning diversion means merely recirculates around the closed loop time and again. When enough of such articles build up, of course, the efficacy of the entire system is severely reduced and/or completely negated since there is no room on the recirculating loop for the introduction of new articles which, in fact, may be properly addressed and/or destined for operating diversion means.
SUMMARY OF THE INVENTION It is an object of this invention, therefore, to provide a novel recirculation limit system for conveyors of the type described.
It is an object of this invention, more particularly, to provide such a system wherein a particular article will be permitted to recirculate in the recirculation system only a specified number of times, thereafter being directed out of the recirculating system into a reject area.
it is an object of this invention, thus, to provide a system adapted for utilization in conjunction with recirculating conveyors which will permit optimum usage of the automatic characteristics of the system despite minor technical problems with addressing systems, diversion means and the like.
These objects are accomplished, briefly, in a closed-loop recirculating conveyor system for sorting articles having destination codes thereon including a closedloop conveyor, an article input conveyor communicating with the closed-loop conveyor, at least two article output conveyors communicating the closed-loop conveyor and a destination-diverting means for diverting articles from the closed-loop conveyor onto said output conveyors in accordance with the destination code thereon. The instant system utilizes a reject conveyor communicating with the closed-loop conveyor, means being provided adjacent the closed-loop conveyor for affixing a reject code to each of the articles which have passed each of the article output conveyors and have not been diverted thereonto by the destination-diverting means. Reject-diverting means are provided for diverting the articles which have the reject code affixed thereto onto said reject conveyor after they have passed each of said outputs a predetermined number of times.
DESCRIlPTlON OF THE FIGURE The FIGURE is a schematic illustration of a recirculating conveyor system constructed in accordance with the teachings of this invention.
Referring now to the FIGURE, there is illustrated what has been depicted as a picking area" it) having a conveyor means 11 running therefrom. The conveyor mechanism ill joins a recirculating conveyor loop 20 at junction 12. The picking area 10, for example, might be a warehouse picking area, such as disclosed in copendingapplication Ser. No. 811,533 filed Mar. 28, 1969, assigned to the same assignee as the instant application. In such a situation, the articles flowing from the picking area 10 along conveyor ll and, thus, onto the recirculating conveyor loop 20 would be cartons of groceries. Each such carton, in accordance with the teachings of the said copending application, would have previously affixecl thereon in the picking area a destination code which, in the present disclosure, would direct it to marshalling area A, marshalling area B, marshalling area C or marshalling area D. In the marshalling areas, of course, the goods are palletized or otherwise arranged for shipment to a specific destination from the warehouse of which the instant system forms a part.
The recirculation conveyor 20 shown in the FlGURE has a series of output conveyors 22a, 22b, 22c and 22d communicating therewith. Each of the output conveyors, as will be readily appreciated by those skilled in the art, convey the articles diverted thereon into one of the specific marshalling areas 24 described heretofore. Diversion onto a particular output conveyor 22a is accomplished by the sensing of the address upon a particular article by an address sensor 21a, 21b, Zilc or 21d and the operation, in response to such sensing, of a diverter means 23a, 23b,23c or 23d, respectively.
If, for example, the particular article placed upon the recirculating loop 20 by conveyor lll is addressed by the means of code-positioned tape for marshalling area A, this fact will be sensed by address sensor 21a and diversion of the article onto output conveyor 22a accomplished by diverter 23a acting in response to a divert signal from address sensor 2lla. Similar results are achieved at output conveyors 22b, 22c and 22d, of course, in the event that the address coded on the article indicates it to be destined for marshalling area 24b, 24c or 24d, respectively.
The address sensors 21, as will be readily apparent to those skilled in the art, may well take the form of a single sensing unit which will be operative to sense which particular output conveyor the article whose address is being read is destined for. This unit, then, will keep track of each article and activate the proper diversion gate at the proper time to divert the article onto its destined output conveyor 22. The separate address sensors, thus, provide merely one way of accomplishing the destination diversion results sought.
Difficulty is often encountered, in systems of the type under discussion, in diverting an article destined for a particular marshalling area onto the proper output conveyor during its initial pass thereby. Such difficulty is caused, ordinarily, by the tendency of the output conveyor to fill to capacity, no further room then being available for the introduction of another article thereonto. in such a situation, conventionally, the article in question merely recirculates completely around the loop w and is discharged or diverted at the proper location during its second pass through the system. if, however, there has been a malfunction at a particular output conveyor or the diverting, palletizing, etc. apparatus associated therewith, the article in question may not be diverted during its second pass through the system. in such a situation, of course, prior art systems have merely permitted the article in question to recirculate around the closed-loop conveyor 40 continually until such time as it' is either removed manually or diverted to the proper location. In a situation such as a grocery warehouse, of course, the recirculating conveyor can quickly become clogged with such articles and, thus, delay the entire order picking and marshalling operation.
Similar difficulty has been experienced with prior art systems of this type when, for one reason or another, the destination address upon the particular article is not readable by the destination sensor or sensors being utilized. In this latter situation, of course, no diversion is even attempted and the improperly addressed article will circulate indefinitely unless it is removed manually. Again, in this situation, a tendency exists for numerous such articles to build up on the recirculating loop impairing markedly the efficacy of the system by preventing the introduction of new articles from the conveyor 11 thereonto.
The preferred embodiment herein disclosed of the instant invention obviates this difiiculty by the provision of a reject conveyor 26 which communicates with the closed-loop conveyor 20 by means of a reject diverting means or gate 27. Articles which are diverted onto the reject conveyor 26 by the reject diverter 27 are routed to a reject area 28 where they may be manually sorted without hindering the operation of the remainder of the system. Diversion onto the reject conveyor 26 is accomplished by means of a reject label applicator 30 and a reject label sensor 31, the latter unit operating the reject diverter 27 in response to sensing of an article with a reject code applied thereto.
Reject label applicator 30 is positioned, as illustrated, downstream (or in the direction of travel 40 of the article along recirculation conveyor 20) from the input conveyor 11 junction 12 and the output conveyor diversion gates 23. An article passing onto the recirculating conveyor 20, thus, passes initially the various output or destination diversion gates 23 and then the reject label applicator 30. The reject label or code applicator 30 is designed and positioned with respect to and/or in conjunction with the recirculating conveyor 20 such that it will automatically place a reject code in a prescribed location on all articles passing thereby. Such a code may, for example, be a piece of retroreflective tape spaced a prescribed distance from the lead edge of the article in question. The position should be chosen, of course, so as not to interfere with the destination address codes which were placed upon the articles in another part of the system nor with the reading thereof by the address sensor or sensors 21.
The article with the reject code applied thereto is then routed past the address sensors 21 one final time. In the event that destination diversion is not achieved at one of the gates 23 during the article's second pass through the system, the reject code which has been applied thereto by applicator 30 is sensed by reject code sensor 31 and diversion gate 27 activated to divert the article in question onto the reject conveyor 26. The article then is routed to the reject area 28 where it is disposed of manually or otherwise.
The instant invention, thus, permits the article to pass by the diversion gates 23 and their associated code sensors 21 on two separate occasions. lf diversion is not accomplished the second time through, the article is diverted into the reject area, preventing the undesirable buildup of constantly recirculating articles noted on the closed-loop or recirculating conveyor 20. The function is achieved through the means of relatively simple, well-known code applicator, code-sensing and conveyor diversion means and can be incorporated into either new or existing systems with little difficulty.
The preferred embodiment of this invention discloses a system wherein articles are permitted to pass by the diversion gates to the marshalling areas two times. Should it be desirable to increase or decrease the number of chances for diversion, it is necessary merely to relocate the position of the reject label applicator and/or provide means for coding the article in accordance with the number of revolutions it has made through the system. If, for example, it were desirable to permit the article to pass by the diversion gates three times prior to being routed onto the reject conveyor 26, a first code could be placed on the article after having passed the destination diverters 23 initially and a second code placed on the articles in response to the presence of the first code after a second pass.
In such a situation, of course, the diverter 27 would be activated upon the sensing by the re ect code sensor 31 of the second code and, thus, without altering the position of the various components the articles in question would recirculate past the destination diverters 23 three separate times before being diverted onto the reject conveyor 26.
While a preferred embodiment of this invention has been described in detail, it will be readily apparent to those skilled in the art that other embodiments may be conceived and fabricated without departing from the spirit thereof. Such other embodiments are to be deemed as included within the scope of the following claims unless these claims, by their language, expressly state otherwise.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: I
1. In a closed-loop recirculating conveyor system for sorting articles having destination codes associated therewith including a closed-loop conveyor; an article input conveyor communicating with said closed-loop conveyor; at least two article output conveyors communicating with said closed-loop conveyor, and destination diverting means for diverting articles from said closed-loop conveyor onto said output conveyors in accordance with the destination codes associated therewith,
the improvement comprising: a reject conveyor communicating with said closed-loop conveyor; means adjacent said closed-loop conveyor for affixing a reject code to each of said articles which have passed each of said article output conveyors and have not been diverted thereonto by said destination-diverting means; and, reject-diverting means for diverting the articles which have said reject code affixed thereto onto said reject conveyor after it has passed each of said outputs a predetermined number of times.
2. The apparatus as set forth in claim 1 wherein said articles pass said affixing means initially after they have passed said reject-diverting means.
3. The apparatus as set forth in claim 2 wherein said reject diverting means is positioned between the last said of said destination diverting means and said affixing means.
4. The apparatus as set forth in claim 1 wherein said articles pass said affixing means initially after they pass said destination-diverting means.