Apparatus and method for formation of multi-region articles

• US 10,207,440 B2
• Filed: 10/07/2014
• Issued: 02/19/2019
• Est. Priority Date: 10/07/2014
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Raleigh, Craig, Balles, Michael G., Hubertz, Craig S., Wilcox, Kurt
• Primary Examiner(s): Thrower, Larry W
• Application Number:
  US14/508,915
• Publication Number:
  US 20160096296A1
• Time in Patent Office: 1,596 Days
• CPC Class Codes: B29C 2045/0027 Gate or gate mark locations
• CPC Class Codes: B29C 45/162 using means, e.g. mould parts, for transferring an injected part between moulding stations
• CPC Class Codes: B29C 45/2673 with exchangeable mould parts, e.g. cassette moulds B29C45/1756 takes precedence
• CPC Class Codes: B29C 45/2681 with rotatable mould parts
• CPC Class Codes: B29C 45/2735 for non-coaxial gates, e.g. for edge gates
• CPC Class Codes: B29L 2011/0016 Lenses

Abstract

An injection-molding apparatus for article formation. The injection-molding apparatus includes a single mold base supporting at least one grouping of a plurality of shape-forming configuration sets. Each set is shaped for forming one layer of a multilayered article comprising an asymmetric surface. Each set may include at least one cavity which retains each article region formed by the preceding injection-molding shot(s). The single mold base includes an internal movable part which moves within the single mold base with respect to a stationary part such that relative positions of the shape-forming configurations are advanced for each set to form a subsequent article region in the cavities. Each subsequent shot may be prior to full cooling of the article region formed in the previous shot.

Claims

1. An injection-molding apparatus comprising a single mold base supporting at least one grouping of shape-forming configuration sets, each set being shaped for forming one layer of a multilayered article comprising an asymmetric surface with two radial sides, one of the shape-forming configuration sets having a shape of one of the radial sides, at least one other shape-forming configuration set having a shape of the other radial side, the formed article layers being retained in the single mold base at least until completion of the last-formed layer of the article.

2. The injection-molding apparatus of claim 1 wherein:

each shape-forming configuration set includes at least one cavity, the formed article layers being retained within the cavity; and

the single mold base comprises an internal movable part which moves within the single mold base with respect to a stationary part such that relative positions of the shape-forming configurations are advanced for each set to form a subsequent article layer in each of the cavities.

3. The injection-molding apparatus of claim 2 wherein:

the single mold base defines an axis;

the movable part supports the cavities and is rotatable about the axis to form subsequent article layers in each cavity.

4. The injection-molding apparatus of claim 2 wherein all of the cavities supported by the movable part are identical.

5. The injection-molding apparatus of claim 1 comprising at least three shape-forming configuration sets.

6. The injection-molding apparatus of claim 1 wherein each shape-forming configuration set is a pair of shape-forming configurations.

7. The injection-molding apparatus of claim 6 wherein one of the shape-forming configurations of each pair is a cavity supported by a stationary part of the single mold base and retaining formed article layers.

8. The injection-molding apparatus of claim 1 wherein each of the formed layers of the article includes at least a portion of one of final surfaces of the article.

9. The injection-molding apparatus of claim 1 being configured such that each subsequent shot is prior to full cooling of the article region formed in the previous shot.

10. The injection-molding apparatus of claim 1 further comprising barrels configured for delivering injection-molding shots to the single mold base, one of the barrels being configured and positioned for delivering thermoplastic material for forming the last-formed article layer, the other of the barrels being configured and positioned for forming article layers prior to the last-formed.

11. The injection-molding apparatus of claim 10 wherein the barrel for the last-formed article layer configured for delivery of thermoplastic material for the corresponding injection-molding shot at a higher pressure than the injection-molding shots delivered by the other barrels.

12. The injection-molding apparatus of claim 1 further comprising at least one grouping of nozzles each corresponding to a particular one of shape-forming configurations, one nozzle of the at least one grouping corresponding to the shape-forming configuration for forming the last-formed article layer and being positioned for delivering the corresponding injection-molding shot at a lateral edge of the finished article.

13. The injection-molding apparatus of claim 12 wherein the other of the nozzles corresponds to shape-forming configurations for forming first-formed and at least one intermediate-formed article layers, each of these nozzles being positioned for delivering thermoplastic material to such position which is over-molded with at least one of the subsequently-formed article layers.

14. The injection-molding apparatus of claim 1 wherein:

the single mold base comprises a stationary part and a movable part which moves internally within the single mold base with respect to the stationary part;

one of the movable and stationary parts supports identical shape-forming configurations of each set; and

the other of the movable and stationary parts supports shape-forming configurations each shaped for one of the article layers.

15. The injection-molding apparatus of claim 14 wherein each shape-forming configuration set is a pair of cavities.

16. The injection-molding apparatus of claim 1 wherein the article is a lens member for transmitting LED light therethrough, the lens member comprising a lens portion and a flange thereabout, the lens portion having the asymmetric surface which is one of inner and outer surfaces.

17. The injection-molding apparatus of claim 16 wherein the shape of each shape-forming configuration set includes at least a portion of one of the inner and outer surfaces of the lens member.

18. The injection-molding apparatus of claim 16 wherein the shape of the shape-forming configuration set for the last injection-molding shot includes the shape of the flange of the lens member for engagement by an ejection system.

19. The injection-molding apparatus of claim 1 wherein the single mold base supports a plurality of the groupings for simultaneous formation of first-formed, at least one of the intermediate-formed and last-formed article layers each for one of a plurality of the articles.

20. The injection-molding apparatus of claim 19 wherein each set includes at least one cavity retaining each article layer formed by at least one preceding injection-molding shot.

21. The injection-molding apparatus of claim 20 further comprising a valve-gate system for balancing each injection-molding shot for equal filling of the cavities, the plurality of the groupings being an even number of the groupings.

22. The injection-molding apparatus of claim 19 wherein the plurality of the groupings comprises eight of the grouping of at least three shape-forming configuration pairs for simultaneously forming eight of each of at least three article layers, thereby simultaneously forming one of the layers for each of at least twenty-four articles.

23. The injection-molding apparatus of claim 19 wherein each of the articles is a lens member for transmitting LED light therethrough, each lens member comprising a lens portion and a flange thereabout, the lens portion having inner and outer surfaces.

24. A method for article formation, the method comprising the steps of:

providing an injection-molding apparatus comprising a single mold base supporting at least one grouping of a plurality of shape-forming configuration sets, each being shaped according to one layer of a multilayered article comprising an asymmetric surface with two radial sides, one of the shape-forming configuration sets having a shape of one of the radial sides, at least one other shape-forming configuration set having a shape of the other radial side;

forming a first-formed region of the article by delivering an injection-molding shot to the respective shape-forming configuration set;

advancing a movable part of the single mold base such that the shape-forming configuration, which retains the first-formed article region, is paired with the shape-forming configuration shaped for the subsequent intermediate-formed region of the article;

delivering an injection-molding shot which forms the intermediate-formed article region at least partially over-molding the article region formed in the preceding injection-molding shot;

further advancing the movable part within the single base such that the shape-forming configuration, which retains the first-formed and the at least one intermediate-formed article region, is paired with the shape-forming configuration corresponding to a subsequent one of the article regions; and

at least partially over-molding the at least one formed intermediate-formed article region with the subsequent one of the article regions by delivering a subsequent injection-molding shot.

25. The method of claim 24 wherein each injection-molding shot is delivered to a corresponding shape-forming configuration pair prior to full cooling of the article region formed in a preceding injection-molding shot.

26. The method of claim 24 wherein the subsequent one of the article regions includes a last-formed article region.

27. The method of claim 24 wherein:

the injection-molding apparatus further comprises at least one grouping of nozzles, each nozzle for delivering an injection-molding shot forming one of the first-formed region, at least one intermediate-formed region and the last-formed region of the article;

the nozzles for forming first-formed and at least one intermediate-formed article regions are each positioned for delivering a corresponding injection-molding shot at a position which is over-molded with at least one of the subsequently-formed article regions; and

the nozzle for forming the last-formed article region is positioned for delivering the corresponding injection-molding shot at a lateral edge of the finished article.

28. The method of claim 24 wherein the step of forming a first-formed region of the article, the step of delivering a subsequent injection-molding shot and the step of at least partially over-molding the at least one intermediate-formed article region are performed simultaneously.

29. The method of claim 28 wherein each injection-molding shot for over-molding at least one formed article region is delivered prior to full cooling of the article region formed in the preceding injection-molding shot.