Low and empty product detection using load cell and load cell bracket

• US 20090151474A1
• Filed: 12/12/2007
• Published: 06/18/2009
• Est. Priority Date: 12/12/2007
• Status: Active Grant

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab, Inc.
• Inventors: Mehus, Richard J., Wiltsie, Ben J., Weber, Bruce W.
• Granted Patent: US 7,694,589 B2
• Time in Patent Office: Days
• US Class Current: 73/862.520
• CPC Class Codes: G01G 17/04 for weighing fluids, e.g. gases, pastes
• CPC Class Codes: G01G 23/01 Testing or calibrating of weighing apparatus
• CPC Class Codes: G01G 23/02 Relieving mechanisms; Arrestment mechanisms
• CPC Class Codes: G01G 3/14 measuring variations of electrical resistance G01G3/13 takes precedence

Abstract

A system and method detect when a product container from which a product is dispensed is empty or nearly empty, and provides a notification of the product status. The system includes a load cell that deflects at a first rate of distance per unit load when a load less than a critical load is positioned to be weighed by the load cell, and a load cell bracket positioned such that the free end of the load cell contacts the load cell bracket when a load substantially equal to or greater than the critical load is positioned to be weighed by the load cell. The load cell bracket may prevent the load cell from further deflection, or it may permit deflection of the load cell at a second rate of distance per unit load when the load cell is in contact with the load cell bracket. The system may generate an out-of-product notification when the amount of product dispensed is substantially equal to zero, a low product notification when the amount of the product remaining is less than a threshold weight or a proof-of-delivery notification.

Claims

1. A system comprising:

a load cell having a fixed end and a free end, wherein the free end of the load cell deflects at a first rate of distance per unit load when a load less than a critical load is positioned to be weighed by the load cell; and

a load cell bracket positioned such that the free end of the load cell contacts the load cell bracket when a load substantially equal to or greater than the critical load is positioned to be weighed by the load cell,

wherein the load cell deflects at a second rate of distance per unit load when the load cell is in contact with the load cell bracket, the second rate of distance per unit load being less than the first rate of distance per unit load.

2. The system of claim 1, wherein the load cell has a maximum rated load, and wherein the critical load is substantially equal to the maximum rated load.

3. The system of claim 1, wherein the load cell generates product weight information associated with an amount of a product remaining in a product container.

4. The system of claim 3, further including a controller that determines an amount of the product dispensed from the product container during a dispensing cycle based on the product weight information received from the load cell.

5. The system of claim 4 wherein the controller generates an out-of-product notification when the determined amount of product dispensed is substantially equal to zero.

6. The system of claim 3 further including a controller that determines the amount of product remaining in the product container after a dispensing cycle based on the product weight information received from the load cell.

7. The system of claim 6 wherein the controller further generates a low product notification when the determined amount of the product remaining is less than a threshold weight.

8. The system of claim 3 wherein the product is one of a solid, a liquid, a powder or a paste.

9. The system of claim 1 further including a controller that generates at least one of an out-of-product notification or a low product notification based on the product weight information received from the load cell.

10. The system of claim 1 wherein the load cell has a maximum rated deflection, and wherein the load cell bracket prevents the load cell from deflecting farther than the maximum deflection.

11. The system of claim 1 wherein the second rate of distance per unit load is substantially equal to 0.

12. The system of claim 1 further comprising a memory that stores calibration data concerning a relationship between the second rate of distance per unit load and the amount of product remaining in the product container.

13. A method comprising:

dispensing a product from a product container during at least one dispensing cycle;

determining whether a product weight remaining in the product container after the at least one dispensing cycle is less than a critical weight;

entering an out-of-product mode when the product weight is less than the critical weight; and

entering a proof of delivery mode when the product weight is not less than a critical weight.

14. The method of claim 13, further comprising determining an amount of product dispensed during the at least one dispensing cycle.

15. The method of claim 14 further comprising generating a notification based on the determined amount of product dispensed during dispensing cycle.

16. The method of claim 14 wherein entering an out-of-product mode includes generating a low product notification when the determined amount of product dispensed is less than a low product threshold amount.

17. The method of claim 14 wherein entering an out-of-product mode includes generating an out-of-product notification when the determined amount of product dispensed is substantially zero.

18. The method of claim 13, wherein determining an amount of product dispensed includes receiving product weight information from a load cell positioned to weigh the product container.

19. The method of claim 13 wherein entering a proof of delivery mode further comprises:

determining an amount of product dispensed during at least one dispense cycle in proof of delivery mode; and

generating a proof of delivery notification when the amount of product dispensed during the at least one dispensing cycle satisfies a proof of delivery threshold.

20. The method of claim 13 further comprising determining an amount of product dispensed during each of a plurality of dispensing cycles.