METHOD AND APPARATUS FOR IMPROVED DETECTION OF HOLES IN PLASTIC CONTAINERS

• US 20110012279A1
• Filed: 03/17/2009
• Published: 01/20/2011
• Est. Priority Date: 03/17/2008
• Status: Abandoned Application

• Current Assignee: Plastic Techniques, Inc.
• Original Assignee: Plastic Techniques, Inc.
• Inventors: Brunella, Adam E., Bogstad, David A., Teitlebaum, Aaron Raphael
• Application Number:
  US12/933,103
• Publication Number:
  US 20110012279A1
• Time in Patent Office: Days
• US Class Current: 264/40.1
• 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 49/80 Testing, e.g. for leaks
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: G01H 3/00 Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G10K 11/28 using reflection, e.g. parabolic reflectors

Abstract

A method and apparatus for monitoring the production of blow molded plastic containers is disclosed, wherein the method and apparatus utilize a sound detector assembly adapted to be positioned adjacent a mold cavity during the introduction of pressure fluid to a preform in the mold cavity to form a container, the sound detector assembly including a reflector having a substantially conic cross-sectional shape and a sound detector and being responsive to a defect sound of the pressure fluid escaping from the interior of the container for generating an output signal.

Claims

1. A method for monitoring the production of blow molded plastic containers to detect a defect in any of the containers comprising the steps of:

a. introducing pressure fluid to an interior of a preform in a mold cavity to form a blow molded plastic container;

b. providing a sound detector assembly including a reflector having a substantially conic section cross-sectional shape and a sound detector;

c. acoustically sensing a defect sound with the sound detector assembly resulting from the pressure fluid escaping from the interior of the container; and

d. generating a control signal in response to the sensed defect sound.

2. The method of claim 1, wherein the sound detector has a parabolic cross-sectional shape.

3. The method of claim 1, wherein the sound detector has a hyperbolic cross-sectional shape.

4. The method of claim 1, wherein the sound detector has an elliptical cross-sectional shape.

5. The method of claim 1, wherein the sound detector has one of a substantially rectangular opening and a substantially circular opening.

6. The method of claim 5, wherein the sound detector has a substantially rectangular opening formed from a pair of curvilinear walls joined together by a pair of rectilinear walls.

7. The method of claim 1, wherein the sound detector includes a support extending between walls thereof.

8. The method of claim 7, wherein the support forms an aperture adapted to receive the sound detector.

9. The method of claim 8, wherein the aperture is disposed at one of a focus of the reflector and along a directrix of the reflector.

10. The method of claim 9, wherein the aperture is disposed at the focus of the reflector and along the directrix of the reflector.

11. The method of claim 1, wherein the step of producing a control signal includes amplifying the control signal.

12. The method of claim 1, further including the step of rejecting the container having a hole therein.

13. The method of claim 12, wherein the step of rejecting the container includes directing pressure fluid to reject the container having a hole therein.

14. An apparatus for monitoring the production of blow molded plastic containers formed by introducing pressure fluid to an interior of a preform in a mold cavity comprising:

a sound detector assembly adapted to be positioned adjacent a mold cavity during the introduction of pressure fluid to a preform in the mold cavity to form a container, said sound detector assembly including a sound detector and a reflector having a substantially conic section cross-sectional shape and being responsive to a defect sound of the pressure fluid escaping from the interior of the container for generating an output signal; and

means for generating a control signal in response to said output signal whereby a container rejecter receiving said control signal rejects the container.

15. The apparatus of claim 14, wherein the reflector has one of a parabolic, hyperbolic, and elliptical cross-sectional shape.

16. The apparatus of claim 15, wherein the reflector has a substantially rectangular opening formed from a pair of curvilinear walls joined together by a pair of rectilinear walls.

17. The apparatus of claim 14, wherein the reflector includes a support extending between walls thereof, the support forming an aperture adapted to receive the sound detector.

18. The apparatus of claim 17, wherein the aperture is disposed at the focus of the reflector and along the directrix of the reflector.

19. An apparatus for monitoring the production of blow molded plastic containers formed by introducing pressure fluid to an interior of a preform in a mold cavity comprising:

a sound detector assembly adapted to be positioned adjacent a mold cavity during the introduction of pressure fluid to a preform in the mold cavity to form a container, said sound detector assembly including a sound detector responsive to a defect sound of the pressure fluid escaping from the interior of the container for generating an output signal and a reflector having a substantially conic section cross-sectional shape and a support extending between walls thereof, the support forming an aperture adapted to receive the sound detector; and

means for generating a control signal in response to said output signal whereby a container rejecter receiving said control signal rejects the container.

20. The apparatus of claim 19, wherein the aperture of the support is disposed at the focus of the reflector and along the directrix of the reflector.