Automatic reject unit spacer and diverter

• US 6,812,426 B1
• Filed: 07/11/2001
• Issued: 11/02/2004
• Est. Priority Date: 07/24/2000
• Status: Active Grant

• Current Assignee: Rapiscan Systems Incorporated (OSI Systems Incorporated)
• Original Assignee: Rapiscan Security Products USA Incorporated (OSI Systems Incorporated)
• Inventors: Kotowski, Andreas F., Gillard-Hickman, Douglas Roy
• Primary Examiner(s): Walsh, Donald P.
• Assistant Examiner(s): Schlak, Daniel K
• Application Number:
  US09/904,206
• Time in Patent Office: 1,210 Days
• Field of Search: 209/589, 209/942, 209/938, 209/546, 209/702, 198/460.1, 198/502.2
• US Class Current: 209/589
• CPC Class Codes: B65G 43/10 Sequence control of conveyors operating in combination
• CPC Class Codes: Y10S 209/942 Operator selects destination of item

Abstract

A method and apparatus for automatic spacing and diverting of packages on a conveyor system ensures an adequate gap between packages deposited onto a loading conveyor for subsequent inspection. A speed ratio between the loading conveyor and an inspection conveyor, a package detector disposed between the loading conveyor and the inspection conveyor, an interruption device controlling the loading conveyor and a controller to permit a signal from the package detector to command the interrupting device to temporarily halt the loading conveyor are used to ensure proper spacing between packages passed to a scanner. The apparatus may also include a package diverter for diverting a package to another area for further inspection.

Claims

1. A system for controlling a plurality of package conveyors, said system comprising:

a loading conveyor nominally operating at a first speed disposed along a conveyor path to transport a first package and a second package, wherein said first package at least initially leads said second package along said conveyor path;

a conveyor interrupter for controllably halting said loading conveyor;

an inspection conveyor operating at a second speed disposed along said conveyor path downstream of said loading conveyor to receive and transport said first and second packages, said second speed being greater than said first speed to produce a first gap between said first package and said second package;

a package detector for sequentially detecting said first and second packages, said package detector comprising a photo-electric cell having an emitter to emit a light beam and a receiver to receive said light beam, said light beam disposed across said conveyor path between said loading conveyor and said inspection conveyor;

a first controller responsive to said package detector, said first controller signaling said conveyor interrupter to halt said loading conveyor for producing a second gap between said first package and said second package, said second gap being based at least in part on measuring a length of time of a period of interruption of said light beam by said first package, said first gap and said second gap together satisfying a minimum specified gap between said first package and said second package when traveling on said inspection conveyor;

a first signal link between said package detector and said first controller;

a second signal link between said conveyor interrupter and said first controller;

an x-ray chamber to scan said first package to produce a scanned image, said x-ray chamber disposed along said conveyor path;

a viewer to display said scanned image for enabling an inspector to view said scanned image;

a third signal link commanded by said inspector for sending a divert signal for diverting said first package from a clearance destination along said conveyor path to a search destination along a search conveyor path;

a conveyor change platform for sending said first package to one of either said conveyor path or said search conveyor path, said conveyor change platform having a platform switch for receiving said divert signal; and

a second controller responsive to said third signal link, said second controller signaling said platform switch to send said first package to said search conveyor path if said divert signal is present and to said conveyor path if said divert signal is absent.

2. A system in accordance with claim 1, wherein said first controller and said second controller are replaced by a single controller.

3. A system in accordance with claim 1, further comprising a fourth signal link from said divert signal to said first controller for controllably halting said loading conveyor.

4. A system in accordance with claim 3 wherein said first controller and said second controller are replaced by a single controller.

5. A system in accordance with claim 1 wherein said receiver has sufficient sensitivity to distinguish between an uninterrupted light beam and an interrupted light beam.

6. A system in accordance with claim 5 wherein when either of said first and second packages is disposed between said loading conveyor and said inspection conveyor said first or second package interrupts said light beam from said emitter to said receiver so that said receiver receives said interrupted light beam, and absence of said first or second package disposed between said loading conveyor and said inspection conveyor permits said receiver to receive an uninterrupted light beam.

7. A method to control a plurality of package conveyors, said method comprising:

depositing a first package on a loading conveyor nominally operating at a first speed and disposed along a conveyor path to transport said first package to an inspection conveyor disposed along said conveyor path;

conveying said first package to said inspection conveyor operating at a second speed greater than said first speed;

detecting said first package by a package detector, said package detector comprising a photo-electric cell having an emitter to emit a light beam and a receiver to receive said light beam, said light beam disposed across said conveyor path between said loading conveyor and said inspection conveyor;

sending a detection signal from said package detector to a first controller, said detection signal being based at least in part on measuring a length of time of a period of interruption of said light beam by said first package;

calculating an interrupt period for controllably halting said loading conveyor in response to said detection signal, said interrupt period producing an actual gap between said first package and a second package that is subsequent to said first package, said actual gap being at least as long as a specified minimum gap;

forwarding said interrupt period to said first controller;

interrupting said loading conveyor by an interrupt command from said first controller in response to said interrupt period;

depositing said first package on said inspection conveyor nominally disposed along said conveyor path to form an inspection path;

transporting said first package to a conveyor change platform disposed along said conveyor path, said conveyor change platform sending said first package to one of either said conveyor path or a search conveyor path;

scanning said first package in an x-ray chamber, said x-ray chamber disposed along said inspection path;

producing a scanned image for enabling an inspector to view said scanned image;

sending a divert signal by said inspector to a second controller; and

commanding by said second controller for said conveyor change platform to send said first package to said search conveyor path if said divert signal is present and to said conveyor path if said divert signal is absent.

8. A method in accordance with claim 7 wherein said first controller and said second controller are replaced by a single controller.

9. A system in accordance with claim 7 further comprising commanding by said second controller for interrupting said loading conveyor.

10. An apparatus to control a plurality of package conveyors including a loading conveyor nominally operating at a first speed and disposed along a conveyor path and an inspection conveyor operating at a second speed greater than said first speed and disposed along said conveyor path, said loading conveyor to transport a first package and a second package that is subsequent to said first package to said inspection conveyor, said apparatus comprising:

means for detecting said first package by a package detector, said package detector comprising a photo-electric cell having an emitter to emit a light beam and a receiver to receive said light beam, said light beam disposed across said conveyor path between said loading conveyor and said inspection conveyor;

means for sending a detection signal from said package detector to a first controller, said detection signal being based at least in part on measuring a length of time of a period of interruption of said light beam by said first package;

means for calculating an interrupt period for controllably halting said loading conveyor in response to said detection signal, said interrupt period producing an actual gap between said first package and said second package, said actual gap being at least as long as a specified minimum gap;

means for forwarding said interrupt period to said first controller;

means for interrupting said loading conveyor by an interrupt command from said first controller in response to said interrupt period;

means for scanning said first package in an x-ray chamber, said x-ray chamber disposed along said conveyor path;

means for producing a scanned image for enabling an inspector to view said scanned image;

means for sending a divert signal by said inspector to a second controller;

means for diverting by a conveyor change platform said first package to one of either said conveyor path or a search conveyor path, said conveyor change platform disposed along said conveyor path; and

means for commanding by said second controller for said conveyor change platform to send said first package to said search conveyor path if said divert signal is present and to said conveyor path if said divert signal is absent.