Conveyor sortation system with parallel divert

• US 5,927,465 A
• Filed: 10/03/1997
• Issued: 07/27/1999
• Est. Priority Date: 10/08/1996
• Status: Expired due to Term

• Current Assignee: Dematic Corporation (KION GROUP AG)
• Original Assignee: Mannesmann Dematic Rapistan Corp. (Siemens AG)
• Inventors: Shearer, James T. Jr.
• Primary Examiner(s): Terrell, William E.
• Assistant Examiner(s): BOWER, KENNETH W
• Application Number:
  US08/943,422
• Time in Patent Office: 662 Days
• Field of Search: 198/890, 198/370.02, 198/890.1, 198/367.1, 198/723, 198/364, 198/717, 198/412, 198/415
• US Class Current: 198/370.02
• CPC Class Codes: B65G 2207/36 Pushing shoes on conveyors
• CPC Class Codes: B65G 47/844 the article-engaging elements being pushers transversally movable on the supporting surface, e.g. pusher-shoes

Abstract

A conveyor diverting system having an endless conveying surface and diverting shoes transversely movable across the conveying surface for diverting articles having an upstream and a downstream diverting track where the upstream diverting track is oriented parallel to the downstream diverting track for a portion of its length, and converges with the downstream diverting track along its other portion. The conveyor system further includes a controller which utilizes only the downstream diverting track if the article to be diverted is less than a first predetermined length or greater than a second predetermined length. If the article to be diverted is between the first predetermined length and the second predetermined length, then both diverting tracks are utilized.

Claims

1. In a conveyor having a longitudinally moving conveying surface defined by a plurality of interconnected generally parallel track surface members connected in spaced relation with each other in an endless web, a plurality of diverter shoes each movably mounted on one of said track surface members for lateral movement with respect to said conveying surface, a diverting system comprising:

guide pins descending from each of said diverter shoes;

a guideway located along a side of said conveyor adapted for receiving said pins and guiding said shoes as they travel with and along a side of said conveying surface;

a pair of diverting tracks adapted to guide said guide pins and located under said conveying surface, said diverting tracks oriented at an angle to said guideway and extending to the other side of said conveyor;

a pair of activatable diverting gates connecting said guideway to said diverting tracks, said diverting gates capable of being in either a diverting state where diverting shoes are diverted from said guideway into said diverting tracks, or in a non-diverting state where said diverting shoes continue to move along said guideway;

sensors located alongside said conveying surface for determining the length of articles conveyed on said conveying surface; and

a controller connected to said sensor, said controller activating both of said pair of said diverting gates when the length of said article is greater than a first predetermined length and less than a second predetermined length, and activating only a single one of said connecting gates when said length of said article is less than said first predetermined length or greater than said second predetermined length.

2. The diverting system of claim 1 wherein said pair of diverting tracks are aligned parallel to each other on the side of said conveying surface nearest to said diverting gates, but meet on the side of said conveying surface opposite to said diverting gates.

3. The diverting system of claim 1 wherein when both of said diverting gates are activated, both of said diverting gates are returned to said non-diverting state after a single diverting shoe has been diverted.

4. The diverting system of claim 1 wherein when only one of said diverting gates is activated, said activated diverting gate remains in said diverting state until a sufficient number of diverting shoes have been diverted to divert said article.

5. A method for diverting articles from a conveyor having a conveying surface defined by a series of laterally extending parallel surface members traveling in a longitudinal direction and a plurality of pushers laterally moveable on said surface members comprising the steps of:

applying a force purely perpendicular to said direction of conveyor motion to the article by engaging the article with two of said pushers;

continuing to apply said perpendicular force to said article for a predetermined period of time; and

after said predetermined period of time, altering said perpendicular force to include a rotational force component along with said perpendicular force.

6. The method of claim 5 further including terminating said rotation force after said article has been rotated a desired amount.

7. The method of claim 6 wherein said desired amount is equal to the angle formed by the intersection of said conveyor with an attached branch conveyor which receives said articles.

8. The method of claim 5 wherein said step of applying said perpendicular force is accomplished by said pushers engaging a pair of diverting tracks located underneath said conveying surface, said diverting tracks being oriented parallel to each other for a predetermined portion of their length and non-parallel to each other for the remaining portion of their length.

9. The method of claim 8 wherein said pair of diverting tracks is defined by an upstream diverting track and a downstream diverting track, said downstream track being straight for its entire length, and said upstream track having a first straight portion and a second portion, said second portion not straightly aligned with said first portion.

10. The method of claim 8 wherein said pair of diverting tracks is defined by an upstream diverting track and a downstream diverting track, said upstream track being a shorter length than said downstream diverting track.

11. A method for diverting articles from a conveyor having a conveying surface defined by a series of laterally extending parallel surface members traveling in a longitudinal direction and a plurality of pushers laterally moveable on said surface members comprising the steps of:

measuring the length of the article to be diverted;

comparing the length of the article to be diverted with a first and second predetermined length, said second predetermined length being greater than said first predetermined length;

applying a perpendicular force and a rotational force to the article by engaging the article with at least one pusher if said article is less than said first predetermined length or greater than said second predetermined force; and

applying a force solely perpendicular to said direction of conveyor motion to the article by engaging the article with two of said pushers if said article is between said first predetermined length and said second predetermined length.

12. The method of claim 11 further comprising the steps of:

continuing to apply said solely perpendicular force to said article when said article is between said first and said second predetermined lengths for a predetermined period of time; and

altering said solely perpendicular force to include a rotational force component along with said perpendicular force, said rotational force component rotating said article to a desired orientation.

13. A conveyor diverting system comprising:

a main conveyor moving in a particular direction;

at least one branch conveyor coupled to said main conveyor such that articles traveling on said main conveyor can be diverted onto said at least one branch conveyor;

a plurality of diver shoes movably mounted on said main conveyor, said diverting shoes movable in a direction generally transverse to the direction of motion of said main conveyor;

a diverting system that selectively moves at least one of said diverting shoes for diverting an article from said main conveyor to said at least one branch conveyor; and

said diverting system adapted to move at least one of said diverting shoes in a manner such that said article initially moves an initial distance in an orientation parallel to said main conveyor and subsequently moves a distance during which said article is rotated.

14. The conveyor diverting system of claim 13 wherein said diverting system includes an upstream and a downstream diverting track.

15. The conveyor diverting system of claim 14 wherein upstream diverting track has a straight portion and a curved portion.

16. The conveyor diverting system of claim 14 wherein said upstream diverting track is comprised of two portions meeting at an angle, one of said portions oriented parallel to said downstream diverting track, and the other of said portions converging with said downstream diverting track.

17. A conveyor diverting system comprising:

an array of movable surface members defining a conveying surface, said conveying surface further defining two sides;

diverting shoes mounted on said surface members and adapted to move transversely across said conveying surface from one of said sides to the other of said sides;

a guide pin extending from below each of said diverting shoes;

a guide track disposed below said array of movable surface member, said guide track adapted to guide said guide pins;

upstream and downstream shoe diverters positioned along and interrupting said guide track, said shoe diverters assuming one of a non-diverting state in which guide pins are guided by said guide track and a diverting state in which said guide pins are diverted from said guide track; and

an upstream and a downstream diverting track positioned underneath said conveying surface and aligned with said upstream and downstream shoe diverters, respectively, said upstream and downstream diverting tracks configured to initially divert articles in an orientation parallel to the direction of movement of said conveying surface and subsequently to rotate the articles being diverted.

18. The conveyor system of claim 17 wherein said upstream diverting track has a straight portion and a curved portion.

19. The conveyor system of claim 17 wherein said upstream diverting track is comprised of two portions meeting at an angle one of said portions oriented parallel to said downstream track, and the other of said portions converging with said downstream diverting track.

20. The conveyor system of claim 17 further comprising:

at least one sensor located along said conveying surface and a controller;

said at least one sensor connected to said controller and providing readings used by said controller to determine the length of an article on said conveying surface; and

said controller connected to said shoe diverters, said controller activating both said shoe diverters when said controller determines that an article is greater than a first predetermined length and less than a second predetermined length that is greater than said first predetermined length, said controller activating only said downstream diverter when said controller determines that the article is less said first predetermined length or is greater than said second predetermined length.

21. A conveyor diverting system comprising:

a main conveyor moving in a particular direction;

at least one branch conveyor coupled to said main conveyor such that articles traveling on said main conveyor can be diverted onto said at least one branch conveyor;

a plurality of divert shoes movably mounted on said main conveyor, said diverting shoes movable in a direction generally transverse to the direction of motion of said main conveyor;

a plurality of shoe diverts capable of being in either a diverting state wherein diverting shoes are diverted transversely across said main conveyor or a non-diverting state wherein diverting shoes are not diverted transversely across said main conveyor;

a control system that activates at least two of said plurality of shoe diverters into a diverting state when an article to be diverted is greater than a first predetermined length and less than a second predetermined length, and activates only a single one of said shoe diverters into a diverting state when said article to be diverted is less than said first predetermined length or greater than said second predetermined length.

22. The conveyor diverting system of claim 21 wherein said control system includes diverting tracks adapted to divert an article across said conveyor initially without rotation of the article and subsequently with rotation of the article when at least two of said shoe diverters are activated into the diverting state.

23. The conveyor diverting system of claim 21 wherein when only one of said shoe diverters is activated into said diverting state, said activated diverting gate remains in said diverting state until a sufficient number of diverting shoes have been diverted to divert said article.

24. The conveyor diverting system of claim 21 wherein when both of said shoe diverters are activated into said diverting state, both of said shoe diverters are returned to said non-diverting state after a single diverting shoe has been diverted by each said shoe diverter.

25. A method for diverting articles from a conveyor having a conveying surface defined by a series of laterally extending parallel surface members traveling in a longitudinal direction and a plurality of pushers laterally moveable on said surface members comprising:

applying a perpendicular force component that is substantially perpendicular to the direction of conveyor motion to an article by engaging the article with at least two of said pushers during an initial portion of a diverting motion; and

altering said perpendicular force component by including a rotational force component with said substantially perpendicular component during a subsequent portion of the diverting motion.

26. The method of claim 25 wherein the applying a perpendicular force component includes moving at least two diverting shoes across said main conveyor.

27. The method of claim 25 further including terminating said rotational force component after the article has been rotated a desired amounted.

28. The method of claim 27 wherein said desired amount of rotation is substantially equal to the angle formed by the intersection of said main conveyor and said branch conveyor.

29. A method of diverting articles from a main conveyor onto a branch conveyor comprising:

providing a plurality of movable pushers which are movable across said main conveyor;

providing a plurality of diverters which cause said pushers to move across said main conveyor when said diverters are activated to a diverting state;

measuring the length of the article to be diverted;

activating at least two of said plurality of diverters when the length of said articles is greater than a first predetermined length and less than a second predetermined length; and

activating only one of said plurality of diverters when the length of said article is less than said first predetermined length or greater than said second predetermined length.

30. The method of claim 29 wherein said activating of at least two of said plurality of diverters occurs only long enough to allow a single pusher to be diverted by each of said diverters.

31. The method of claim 30 wherein said activating of only a single one of said plurality of diverting gates occurs long enough to allow sufficient pushers to be diverted for diverting the article onto the branch conveyor.