Conveyor jam detection system and method

• US 9,477,220 B2
• Filed: 05/01/2015
• Issued: 10/25/2016
• Est. Priority Date: 05/13/2014
• Status: Active Grant

• Current Assignee: SICK Incorporated (Sick)
• Original Assignee: SICK Incorporated (Sick)
• Inventors: Shteinfeld, Alexander, Lydon, Richard
• Primary Examiner(s): Bidwell, James R
• Application Number:
  US14/702,131
• Publication Number:
  US 20150329296A1
• Time in Patent Office: 543 Days
• Field of Search: 198/502.1, 198/502.3
• 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 distance detector located on one side of a conveyor oriented to measure 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 distance measurements differ greater than a threshold,

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

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

2. The system of claim 1 further including means for detecting whether the conveyor is moving.

3. The system of claim 1 or 2 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.

4. A conveyor jam detection method comprising:

measuring the distance to parcels on a conveyor and outputting a distance measurement signal;

comparing distance measurement signals;

calculating differences in consecutive distance measurements;

resetting a jam count if the difference is greater than a threshold;

incrementing the jam count if the difference is less than the threshold; and

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

5. The method of claim 4 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.