CONVEYOR JAM DETECTION SYSTEM AND METHOD

• US 20150329296A1
• Filed: 05/01/2015
• Published: 11/19/2015
• Est. Priority Date: 05/13/2014
• Status: Active Grant

• Current Assignee: SICK Incorporated (Sick)
• Original Assignee: SICK Incorporated (Sick)
• Inventors: Shteinfeld, Alexander, Lydon, Richard
• Granted Patent: US 9,477,220 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B65G 43/08 Control devices operated by article or material being fed, conveyed or discharged and controlling the discharging devices B65G47/42
• CPC Class Codes: G05B 19/0428 Safety, monitoring G05B19/0423 takes precedence
• CPC Class Codes: G05B 19/4189 characterised by the transport system
• CPC Class Codes: G05B 2219/31272 Avoid piling up, queue of workpieces, accommodate surges
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A conveyor jam detection system and method includes a distance detector located on one side of a conveyor oriented to detect the distance from the detector to parcels on the conveyor. A controller is responsive to the distance detector and is configured to compare distance measurements, to reset a jam count if different distance measurements over time are greater than a threshold, to increment the jam count if different distance measurements over time are less than the threshold, and output a jam condition signal if the jam count exceeds a set limit.

Claims

1. A conveyor jam detection system comprising:

a detector located on one side of a conveyor configured in a jam condition to measure the distance to a stationary parcel and to output a constant distance measurement signal and, in a non jam condition, to measure the distance to a first moving parcel and then to measure the distance to a second moving parcel at a different distance from the detector than the first moving parcel and to output a varying distance measurement signal; and

a controller receiving signals from the detector and configured to determine if a jam condition exists based on the constant distance measurement signal and to determine if a non-jam condition exists based on the varying distance measurement signal.

2. The system of claim 1 in which the controller is configured to determine if a jam condition exists by incrementing a jam count when a constant distance measurement signal is received from the detector and to output a jam condition signal if the jam count exceeds a set limit.

3. The system of claim 2 in which the controller is configured to determine if a non-jam condition exists by resetting the jam count when a varying distance measurement signal is received.

4. The system of claim 2 in which a controller is configured to determine if a jam condition exists by further determining if the conveyor is moving and outputting a jam condition signal if the conveyor is moving and the jam count exceeds a set limit.

5. A conveyor jam detection method comprising:

measuring the distance to a stationary parcel and outputting a constant distance measurement signal;

measuring the distance to a first moving parcel and measuring the distance to a second moving parcel at a different distance than a first moving parcel and, in response, outputting a varying distance measurement signal;

determining if a jam condition exists based on the constant distance measurement signal; and

determining if a non-jam condition exists based on the varying distance measurement signal.

6. The method of claim 5 in which determining if a jam condition exists includes incrementing a jam count when a constant distance measurement signal is received and outputting a jam condition signal if the jam count exceeds a set limit.

7. The method of claim 6 in which determining if a non-jam exists includes resetting the jam count in response to a varying distance measurement signal.

8. The method of claim 6 in which determining if a jam condition exists includes determining if the conveyor is moving and outputting a jam condition signal only if the conveyor is moving and the jam count exceeds the set limit.

9. A conveyor jam detection system comprising:

a distance detector located on one side of a conveyor oriented to detect the distance from the detector to parcels on the conveyor;

a controller responsive to the distance detector and configured;

to compare distance measurements,

to reset a jam count if different distance measurements are greater than a threshold,

to increment the jam count if different distance measurements are less than the threshold, and

output a jam condition signal if the jam count exceeds a set limit.

10. The system of claim 9 further including means for detecting whether the conveyor is moving.

11. The system of claim 10 in which the controller is responsive to the means for detecting when the conveyor is moving and is further configured to output a jam condition signal if the jam count exceeds the set limit and the conveyor is moving.

12. A conveyor jam detection method comprising:

measuring the distance of parcels on a conveyor from a set location;

detecting whether the conveyor is moving; and

detecting a jam condition based on whether the conveyor is moving and any changes of measured distances of a parcel over time.