CONTAINER INSPECTION UTILIZING LINEAR FORCE ACTUATOR

• US 20110056275A1
• Filed: 09/01/2010
• Published: 03/10/2011
• Est. Priority Date: 09/08/2009
• Status: Active Grant

• Current Assignee: Industrial Dynamics Company, Ltd. (Kestrel Vision)
• Original Assignee: Industrial Dynamics Company, Ltd. (Kestrel Vision)
• Inventors: Kriebel, David, Calhoun, Steve, Barmeyer, Andrew
• Granted Patent: US 8,578,760 B2
• Time in Patent Office: Days
• US Class Current: 73/41
• CPC Class Codes: G01M 3/32 for containers, e.g. radiators

Abstract

Container inspection utilizing a linear actuator. A linear actuator shaft is movable such that the shaft end temporarily contacts the container. A feedback parameter resulting from or related to a change of an electrical property of the linear actuator, is detected or determined by a controller, which determines whether the container satisfies pre-determined inspection criteria, e.g., whether the container is properly sealed, satisfies pressure criteria and/or has unacceptable vacuum. These determinations are made based at least in part upon one or more detected feedback parameters including or related to at least one of a change of position of the shaft, a change of velocity of the shaft and a force or torque exerted by the container to the shaft. In this manner, high speed leak detection is performed without a load cell or force transducer, without squeezing or compressing bottles and without determining fill level changes.

Claims

1. A method of inspecting a container, the method comprising:

transporting a container on a conveyor to an inspection area, the container being positioned between a support member in the inspection area and a distal end of a translatable member of an electronically controlled linear actuator operably coupled to a controller;

activating the electronically controlled linear actuator in response to an output of the controller to move the translatable member from an initial position at which a distal end of the translatable member does not engage a portion of the container to an extended position at which the distal end temporarily engages the portion of the container and pushes the container against the support member;

detecting, without a load cell or force transducer, an electrical feedback parameter resulting from the translatable member contacting the portion of the container, the electrical feedback parameter comprising an electrical attribute of the linear actuator;

providing the detected electrical feedback controller as an input to the controller; and

determining, with the controller, whether the container satisfies pre-determined inspection criteria based at least in part upon the detected electrical feedback parameter.

2. The method of claim 1, the distal end of the translatable member contacting a flexible sidewall of the container.

3. The method of claim 1, the distal end of the translatable member contacting a portion of a flexible first container made of plastic, aluminum, paperboard, a flexible metals or a foil.

4. The method of claim 1, the distal end of the translatable member contacting a flexible cap or lid of the container.

5. The method of claim 1, the controller and the electronically controlled linear actuator forming a closed loop feedback system for controlling the translatable member and detecting the electrical feedback parameter.

6. The method of claim 1, the pre-determined inspection criteria comprising whether the container is properly sealed, and determining whether the container is properly sealed being performed without compressing the container between belts and without determining a fill level of the container.

7. The method of claim 1, the controller determining a torque or force exerted by the container when the distal end of the translatable member contacts the container, the torque or force being determined based at least in part upon the detected electrical feedback parameter.

8. The method of claim 7, the torque or force being determined based at least in part upon a detected current of the linear actuator.

9. The method of claim 7, further comprising rejecting or sorting the container if the torque or force does not satisfy pre-determined torque or force criteria.

10. The method of claim 7, the detected electrical feedback being parameter being related to a component upstream of the linear actuator.

11. The method of claim 1, the detected electrical feedback parameter being related to a change of velocity of the translatable member.

12. The method of claim 11, the change of velocity comprising a difference between a first velocity of the translatable member prior to contacting the portion of the container and a second velocity of the translatable member when the translatable member contacts the container.

13. The method of claim 12, further comprising rejecting or sorting the container if the change of velocity or a force related to the change of velocity satisfies pre-determined velocity or force criteria.

14. The method of claim 1, the detected electrical feedback parameter being related to a change of position of the translatable member, the change of position being based at least in part upon a first, extended position of the translatable member resulting from the distal end of the translatable member moving freely and being unencumbered by the container, and a second position at which the translatable member contacts the portion of the container.

15. The method of claim 1, the container being moved in a first direction by a conveyor, and the translatable member being moved in a linear manner in a second direction that is substantially perpendicular to the first direction.

16. The method of claim 15, the linear actuator being positioned above the container, and the second direction being substantially parallel to an axis defined by the container.

17. The method of claim 1, the support member being rotatable to support the container on the conveyor while the container is transported on the conveyor.

18. The method of claim 17, the support member comprising a star wheel or a worm gear.

19. The method of claim 1, further comprising detecting at least one additional feedback parameter, wherein determining whether the container satisfies pre-determined criteria is based at least in part upon at least two detected electrical feedback parameters.

20. The method of claim 19, determining whether the container satisfies pre-determined inspection criteria being based at least in part upon electrical feedback parameters related to a change of velocity of the translatable member, a change of position of the translatable member, and a torque or force exerted by the container on the translatable member.

21. The method of claim 1, the pre-determined inspection criteria comprising whether the container is properly sealed, has excessive pressure, insufficient pressure, or inadequate vacuum.

22. The method of claim 1, further comprising:

transporting the container past the inspection area and transporting a second container to the inspection area, the second container being positioned between the support member in the inspection area and the distal end of the translatable member;

activating the electronically controlled linear actuator in response to an output of the controller to move the translatable member from the an initial position at which a distal end of the translatable member does not engage a portion of the second container to an extended position at which the distal end temporarily engages the portion of the second container and pushes the second container against the support member;

detecting, without a load cell or force transducer, a second electrical feedback parameter resulting from the translatable member contacting the portion of the second container, the second electrical feedback parameter comprising a second electrical attribute of the linear actuator;

providing the detected second electrical feedback controller as an input to the controller;

determining, with the controller, whether the second container satisfies pre-determined inspection criteria based at least in part upon the detected second electrical feedback parameter.

23. The method of claim 22, the conveyor being in continuous motion while the linear actuator engages the first container and the second container.

24. The method of claim 1, the translatable member being moved at a fixed velocity against the container while measuring the position of the translatable member using an encoder attached directly to the translatable member.

25. A container inspection system, comprising:

a conveyor for transporting a container to an inspection area including a support member;

a linear actuator comprising a translatable member, the container being positionable between the support member and a distal end of the translatable member;

a controller operably coupled to the linear actuator, the controller being configured to cause movement of the translatable member from an initial position at which the distal end of the translatable member does not engage a portion of the container to an extended position at which the distal end temporarily engages the portion of the container and pushes the container against the support member, and to detect, without a load cell or force transducer, an electrical feedback parameter resulting from the translatable member contacting the portion of the container, the electrical feedback parameter comprising an electrical attribute of the linear actuator, the controller being further configured to determine whether the container satisfies pre-determined inspection criteria based at least in part upon the detected electrical feedback parameter.

26. The system of claim 25, the container and the linear actuator being arranged such that the linear actuator contacts a flexible sidewall of the container when the linear actuator is in the extended position.

27. The system of claim 25, the container and the linear actuator being arranged such that the linear actuator contacts a flexible cap or lid of a substantially rigid container when the linear actuator is in the extended position.

28. The system of claim 25, the controller and the electronically controlled linear actuator forming a closed loop feedback system for controlling the translatable member and detecting the electrical feedback parameter.

29. The system of claim 25, the controller being configured to determine whether the container satisfies pre-determined inspection criteria without the container being compressed with belts and without determining or sensing a fill level of the container.

30. The system of claim 25, the controller being configured to determine a torque or force exerted by the container when the distal end of the translatable member contacts the container, the torque or force being determined based at least in part upon the detected electrical feedback parameter.

31. The system of claim 30, the torque or force being determined based at least in part upon a detected current of the linear actuator.

32. The system of claim 25, the detected electrical feedback parameter being related to a change of velocity of the translatable member.

33. The system of claim 32, the change of velocity comprising a difference between a first velocity of the translatable member prior to contacting the portion of the container and a second velocity of the translatable member when the translatable member contacts the container.

34. The system of claim 25, the controller being configured to detect at least two electrical feedback parameters and to determine whether the container satisfies pre-determined inspection criteria based at least in part upon the at least two electrical feedback parameters.