APPARATUS AND METHOD FOR SENSING CONDITIONS LOCAL TO A MODULAR CONVEYOR BELT

• US 20090194391A1
• Filed: 02/06/2008
• Published: 08/06/2009
• Est. Priority Date: 02/06/2008
• Status: Active Grant

• Current Assignee: Laitram LLC
• Original Assignee: Laitram LLC
• Inventors: Lagneaux, Jason M.
• Granted Patent: US 7,635,060 B2
• Time in Patent Office: Days
• US Class Current: 198/810.04
• CPC Class Codes: B65G 17/086 specially adapted to follow a curved path for individual load carriers B65G17/22
• CPC Class Codes: B65G 2203/042 Sensors
• CPC Class Codes: B65G 2207/30 Modular constructions
• CPC Class Codes: B65G 43/02 detecting dangerous physical condition of load carriers, e.g. for interrupting the drive in the event of overheating
• CPC Class Codes: G01L 5/101 using sensors inserted into the flexible member

Abstract

Apparatus and method for sensing conditions local to a modular conveyor belt and wirelessly transmitting signals representing those conditions to an off-belt belt monitoring system. In a preferred version, a load cell pin installed in a clevis formed at a hinge joint between adjacent rows of a modular conveyor belt serves as a clevis pin to interconnect the rows and as a sensor sensitive to belt tension transmitted through the clevis. A special load-sensing belt module forms the clevis and holds electronic circuitry that takes the measurements made by the sensor, logs them in a memory element, and transmits them wirelessly to the belt monitoring system. The measurements may also be used as part of a closed-loop control system to control the speed or other operating characteristics of the conveyor system. Furthermore, a variety of sensors housed in sensor modules similar to standard conveyor belt modules may be installed in the belt as drop-in replacements for standard modules.

Claims

1. A modular conveyor belt comprising:

a series of rows of one or more belt modules linked together at hinge joints by hinge rods received in lateral passageways formed in interleaved hinge elements of adjacent rows of belt modules;

wherein at least one of the belt modules is a load-sensing belt module that includes a load sensor making measurements of belt tension in at least a portion of the load-sensing belt module.

2. A modular conveyor belt as in claim 1 wherein the load-sensing belt module further includes a transmitter to wirelessly transmit signals representative of the measurements of belt tension made by the load sensor.

3. A modular conveyor belt as in claim 1 wherein the load-sensing belt module further includes a memory element for storing a series of measurements of belt tension made by the load sensor.

4. A modular conveyor belt as in claim 1 wherein the load-sensing belt module further includes one or more electrical cells to power the load sensor.

5. A modular conveyor belt as in claim 1 wherein the load sensor includes a pin portion that is received in a portion of one of the lateral passageways at a hinge joint and is subjected to shear stress caused by belt tension.

6. A modular conveyor belt as in claim 5 wherein the load-sensing belt module and an adjacent belt module form a clevis at the hinge joint and wherein the pin portion of the load sensor serves as a clevis pin for the clevis connecting the load-sensing belt module to the adjacent belt module.

7. A modular conveyor belt as in claim 1 wherein the load-sensing belt module further includes:

electronic components for storing the measurements of belt tension and for transmitting signals representative of the measurements;

a cavity housing the electronic components; and

a cover over the cavity to retain the electronic components.

8. A modular conveyor belt as in claim 1 wherein the load-sensing belt module includes a clevis at one end and wherein the load sensor includes a pin portion that serves as a clevis pin for the clevis and wherein a conveyor belt module adjacent the load-sensing belt module includes a projection rotatable about the pin portion.

9. A modular conveyor belt as in claim 8 further comprising a bearing rotatable about the axis of the pin portion within the clevis and rotatably received by the projection of the adjacent belt module to allow the adjacent belt module to pivot about the bearing about an axis radial to the axis of the pin portion.

10. A modular conveyor belt as in claim 1 wherein the load-sensing belt module is positioned at an outside edge of the modular conveyor belt.

11. A modular conveyor belt as in claim 1 wherein the load-sensing module includes a plurality of laterally spaced apart hinge elements along one end and fewer laterally spaced hinge elements along the other end.

12. A modular conveyor belt as in claim 1 wherein the load-sensing belt module has a hinge element structure similar to that of another belt module in a position in the belt to allow for drop-in replacement of the belt module in the position by the load-sensing module.

13. A modular conveyor belt as in claim 1 further comprising a controller producing a motor-control signal from the sensor measurement to control the operation of the belt.

14. A modular plastic conveyor belt comprising:

a series of rows of one or more standard belt modules linked together at hinge joints by hinge rods received in lateral passageways formed in interleaved hinge elements of adjacent rows of belt modules;

at least one sensor module including;

a sensor making measurements of a local condition;

a memory element for storing the measurements; and

a transmitter for wirelessly transmitting signals representing the measurements.

15. A modular plastic conveyor belt as in claim 14 wherein the at least one belt module has a cavity in which the memory element and the transmitter are embedded.

16. A modular plastic conveyor belt as in claim 14wherein the sensor is a load cell measuring tension in the modular conveyor belt.

17. A modular conveyor belt comprising:

a series of rows of one or more standard belt modules having hinge element structure at opposite ends, the belt modules linked together at hinge joints by hinge rods received in lateral passageways formed in interleaved hinge elements of adjacent rows of belt modules;

a sensor module that includes;

a sensor making measurements of a local condition;

a transmitter for transmitting signals representing the measurements; and

hinge element structure similar to the hinge element structure of at least one of the standard belt modules so as to make the sensor module capable of replacing one of the standard modules without changing the length of the modular conveyor belt.

18. A method for measuring tension in a modular conveyor belt constructed of a series of rows of one or more belt modules hingedly linked together by hinge rods in lateral passageways forming hinge joints between adjacent rows of belt modules, the method comprising:

installing a load cell having a pin portion in a portion of a lateral passageway at a hinge joint to serve as a hinge pin linking adjacent rows together and to make measurements of tension in the modular conveyor belt.

19. The method of claim 18 further comprising wirelessly transmitting signals representing the measurements from one of the modules in the modular conveyor belt.

20. The method of claim 18 further comprising logging the measurements in a memory element disposed in one of the modules in the modular conveyor belt.

21. The method of claim 20 further comprising wirelessly transmitting a signal representing a series of the measurements logged in the memory element.

22. The method of claim 18 further comprising installing the load cell in an edge portion of the modular conveyor belt.

23. A method for measuring a local condition in a modular conveyor belt constructed of a series of rows of one or more standard belt modules having hinge element structure at opposite ends, the belt modules linked together at hinge joints by hinge rods received in lateral passageways formed in interleaved hinge elements of adjacent rows of belt modules, the method comprising:

removing or omitting a standard belt module from a row of the modular conveyor belt;

replacing the standard belt module in the row with a first sensor module having hinge element structure like that of the removed or omitted module and further having a sensor sensing a local condition and making a measurement representing the local condition.

24. The method of claim 23 further comprising:

maintaining an inventory of sensor modules, each including a sensor sensitive to a different local condition and each having hinge element structure like that of the removed or omitted module; and

replacing a standard belt module or the first sensor module with another sensor module selected from the inventory of sensor modules.

25. The method of claim 23 further comprising:

transmitting the measurement from the modular conveyor belt to a controller; and

using the controller to adjust the local condition sensed by the sensor.