Bottle inspection along molder transport path

• US 5,591,462 A
• Filed: 11/21/1994
• Issued: 01/07/1997
• Est. Priority Date: 11/21/1994
• Status: Expired due to Term

• Current Assignee: Pressco Technology Inc.
• Original Assignee: Pressco Technology Inc.
• Inventors: Francis, Trent G., Wright, Paul L., Gold, Daniel B., Williams, Brad L., Sands, Peter J., Cochran, Phillip, Delater, David B., Darling, Donald T., Pentel, Jerry, Dewar, Harold L.
• Primary Examiner(s): Chiesa, Richard L.
• Application Number:
  US08/343,015
• Time in Patent Office: 778 Days
• Field of Search: 425/140, 425/169, 425/522, 425/534, 425/525, 425/162, 425/165, 425/173, 356/240, 356/237, 250/223 B, 348/127, 209/526, 209/524, 65/158, 65/165, 65/264, 65/267, 65/377
• US Class Current: 425/173
• CPC Class Codes: B29C 2949/0715 the preform having one end closed
• CPC Class Codes: B29C 49/06 Injection blow-moulding
• CPC Class Codes: B29C 49/4238 Ejecting defective preforms or products
• CPC Class Codes: B29C 49/80 Testing, e.g. for leaks
• CPC Class Codes: G01N 21/9081 Inspection especially designed for plastic containers, e.g. preforms

Abstract

Camera based inspection equipment is used in conjunction with a multiple-station forming device such as a blow molder for polyethylene terephthalate (PET) or PEN bottle manufacturing. The inspection system relies on handling devices that present successive bottles for imaging, and due to their operation with the forming device it is possible to correlate inspection data with individual forming elements and/or transfer elements. A seal surface inspection module, a base/neck fold inspection module and a finish gauge inspection module are integrated into the route of preforms and containers through the container manufacturing equipment such that the inspection system is directed to view the passing bottles as they are carried on the transfer devices needed to load and unload the molder. The base/neck fold examines the lower portion of the bottles in elevation and plan view at the predetermined angle of orientation of the bottles on their longitudinal axes, maintained from the mold cavity to the inspection system, for examining the folds in the bottoms of the bottles. The seal surface module examines the surface to be sealed against a cap, in an axial inspection view. The finish gauge inspection module examines the threads and flanged neck.

Claims

1. A container inspection system in combination with a container manufacturing system, comprising:

a molder formed with at least one cavity, the molder being coupled to a preform feed means and having at least one cavity for receiving a succession of preforms and to form the preforms to a shape of the cavity, the molder forming a container with a top seal means on a neck formed with an opening, and a base;

a transfer means positioned after the blow molder along a transport path, and being operable to remove each container from the cavity and to transport the container along the transport path toward an exit means, the transfer means maintaining a predetermined rotational position of each container received from the molder;

at least one optical inspection device disposed along the transport path between the molder and the exit means, the transfer means presenting the container to the inspection system at said predetermined rotational position for each successive container, the at least one optical inspection device being operable to capture an image of at least part of the container and being coupled to a processor for analyzing the image for defects in the container;

at least one of an additional optical inspection device and a rejection means coupled along the transport path, and being coupled to the processor, the processor having means coupled to the transport path for coordinating operation of the at least one optical inspection device and said processor correlating operation of at least one of the optical inspection device, the additional optical inspection device and the rejection means, as to individual ones of the containers, whereby defective operation of the cavity of the molder and the transfer means can be identified.

2. The combination of claim 1, wherein the molder is a blow molder and the cavity is circularly asymmetric so as to form the container with a shape having a distinct appearance at different rotational positions.

3. The combination of claim 2, wherein the molder forms bottles having folds in a base thereof, the folds being disposed at particular angles relative to the predetermined rotational position of the containers.

4. The combination of claim 2, wherein the molder is a blow molder operable to form petaloid polyethylene terephthalate bottles having folds in a base thereof, formed by the cavity.

5. The combination of claim 4, wherein the inspection system comprises a base/neck fold module operable to record an image including the folds.

6. The combination of claim 5, further comprising said additional optical inspection device, including at least one of a seal surface inspection module and a finish gauge module, each operable to record an image of the container independent of rotational position of the container.

7. The combination of claim 6, wherein the finish gauge inspection module comprises a U-shaped chassis having two downward extending legs joined by a center yoke section, a first light source, at least one reflecting mirror and a camera, the light source being positioned to illuminate an area between the downward extending legs of the U-shaped chassis, the camera being positioned to image the bottle when the bottle is positioned within the area between the downward extending legs of the U-shaped chassis while the bottle is being transported along the transport path.

8. The combination of claim 5, wherein the base/neck fold inspection module further comprises an upper module operable to inspect the base of the bottle and a lower module operable to inspect the neck area of the bottle while the bottle is being transported along the transport path.

9. The combination of claim 8, wherein the lower module comprises a U-shaped chassis having two upward extending legs joined by a center yoke section, the lower module having a first light source, at least one reflecting mirror and a camera, the first light source being positioned to illuminate the area between the upward extending legs of the U-shaped chassis, the camera being positioned to image the bottle when the bottle is positioned within the area between the upward extending legs of the U-shaped chassis.

10. The combination of claim 8, wherein the lower module further comprises a second light source positioned in the center yoke section operable to direct light in the upward direction parallel to the direction of the upward extending legs.

11. The combination of claim 10, wherein the upper module comprises a rectangular chassis and a camera.

12. The combination of claim 11, wherein the upper module is located above the lower module such that upper module camera is directed at the second light source in the lower module, the upper module camera being operable to image the base of the bottle by viewing the base through the opening in the neck when the bottle is positioned below the camera and above the second light source.

13. The combination of claim 1, further comprising an operator interface system having a processing means in data communication with the at least one optical inspection device, the processing means being operable to analyze for defects in the container that are detected by said inspection device and to actuate the rejection means such that a defective container is diverted along the transport path.

14. The combination of claim 13, further comprising means for triggering the optical inspection device to record the image at the predetermined rotational position of the container.

15. A container inspection system in combination with a container manufacturing system, comprising:

a molding means having a plurality of cavities, the molding means being operable to form a container defined by the shape of the plurality of cavities, the container having a top seal means on a neck formed with an opening, and a base;

a transfer means having a plurality of transfer arms being positioned after the molding means along a transport path, and being operable to remove each container from the cavity and to transport the container along the transport path toward an exit means, the transfer means maintaining a predetermined rotational position of each container received from the molding means;

an optical inspection system disposed along the transport path between the molding means and the exit means, the transfer means presenting the container to the optical inspection system at said predetermined rotational position for each successive container, the optical inspection system being operable to capture an image of at least part of the container and being coupled to a processor for analyzing the image for defects in the container, the processor being operable to correlate defects detected in the container to the cavity in which the container was formed; and

,

a rejection means coupled along the transport path, and being responsive to the processor for diverting selected ones of the containers as a function of the defects.

16. The container inspection system of claim 15 wherein the processor is operable to correlate defects detected in the container to the transfer arm which removed the container from the cavity.

17. The container inspection system of claim 16 wherein the processor is operable to store defect data for each of the plurality of cavities and transfer arms.

18. The container inspection system of claim 17 wherein the processor is operable to display the defect data on a display screen.

19. The container inspection system of claim 18 wherein the processor is operable to display the detect in the form of a histogram.

20. A container inspection system in combination with a container manufacturing system, comprising:

molding means operable to form a container from a heated preform, the container having a top seal means on a neck formed with an opening, and a base;

transfer means positioned after the molding means along a transport path, and being operable to move containers away from molding means along the transport path toward an exit means, at least one of the molding means and the transfer means having a plurality of container engaging elements such that successive ones of the containers are engaged by different ones of the container engaging elements;

an optical inspection system disposed along the transport path between the molding means and the exit means, the optical inspection system being operable to capture an image of at least part of the container and being coupled to a processor for analyzing the image for defects in the container, the processor being operable to correlate defects detected in the container to particular ones of said container engaging elements.

21. The combination of claim 20, wherein the inspection system comprises a base/neck fold module disposed adjacent to the transfer means, the base/neck fold module being operable to record an image of the base and neck of the container.

22. The combination of claim 21, further comprising at least one of a seal surface inspection module disposed adjacent to the transfer means, the seal surface inspection module being operable to record an image of the seal surface of the container.

23. The combination of claim 22, further comprising an operator interface system having a processing means in data communication with the optical inspection system, the processing means being operable to analyze for defects in the container that are detected by the optical inspection system and to actuate the rejection means such that a defective container is diverted along the transport path.

24. The combination of claim 23, further comprising means for triggering the optical inspection system to record the image at the predetermined rotational position of the container.

25. The combination of claim 21, wherein the base/neck fold inspection module further comprises an upper module operable to inspect the base of the bottle and a lower module operable to inspect the neck area of the bottle while the bottle is being transported along the transport path.

26. The combination of claim 25, wherein the lower module comprises a U-shaped chassis having two upward extending legs joined by a center yoke section, the lower module having a first light source, at least one reflecting mirror and a camera, the first light source being positioned to illuminate the area between the upward extending legs of the U-shaped chassis, the camera being positioned to image the bottle when the bottle is positioned within the area between the upward extending legs of the U-shaped chassis.

27. The combination of claim 26 wherein the lower module further comprises a second light source positioned in the center yoke section operable to direct light in the upward direction parallel to the direction of the upward extending legs.

28. The combination of claim 27, wherein the upper module comprises a rectangular chassis and a camera.

29. The combination of claim 28, wherein the upper module is located above the lower module such that the upper module camera is directed at the second light source in the lower module, the upper module camera being operable to image the base of the bottle by viewing the base through the opening in the neck when the bottle is positioned below the camera and above the second light source.

30. The combination of claim 22, wherein the exit means is an exit star wheel operable to hold the container about the body such that the neck area is unobstructed.

31. The combination of claim 30, further comprising at least one final gauge module disposed adjacent to the exit star wheel, the final gauge module being operable to record an image of the container including the neck area.

32. The combination of claim 31, wherein the finish gauge module comprises a U-shaped chassis having two downward extending legs joined by a center yoke section, a first light source, at least one reflecting mirror and a camera, the light source being positioned to illuminate an area between the downward extending legs of the U-shaped chassis, the camera being positioned to image the bottle when the bottle is positioned within the area between the downward extending legs of the U-shaped chassis while the bottle is being transported along the transport path.