LED light fixture including optical member with in-situ-formed gasket and method of manufacture

• US 9,470,394 B2
• Filed: 11/24/2014
• Issued: 10/18/2016
• Est. Priority Date: 11/24/2014
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Kinnune, Brian, Goelz, Dave
• Primary Examiner(s): Landau, Matthew
• Assistant Examiner(s): WITHERS, GRANT S
• Application Number:
  US14/551,656
• Publication Number:
  US 20160146425A1
• Time in Patent Office: 694 Days
• US Class Current: 1/1
• CPC Class Codes: B29C 45/14336 Coating a portion of the article, e.g. the edge of the article B29C45/14573 and B29C45/14598 take precedence
• CPC Class Codes: B29D 11/0073 Optical laminates
• CPC Class Codes: B29K 2021/003 Thermoplastic elastomers
• CPC Class Codes: B29K 2101/12 Thermoplastic materials
• CPC Class Codes: B29K 2105/253 Preform
• CPC Class Codes: B29K 2995/0003 having particular electrical or magnetic properties, e.g. piezoelectric
• CPC Class Codes: B29K 2995/0036 Electroluminescent
• CPC Class Codes: B29L 2011/00 Optical elements, e.g. lenses, prisms
• CPC Class Codes: B29L 2031/265 Packings, Gaskets
• CPC Class Codes: F21K 9/90 Methods of manufacture
• CPC Class Codes: F21V 19/001 the light sources being semiconductors devices, e.g. LEDs
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 31/005 Sealing arrangements therefor
• CPC Class Codes: F21V 5/007 Array of lenses or refractors for a cluster of light sources, e.g. for arrangement of multiple light sources in one plane combination of two or more refractors F21V5/008
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An LED light fixture including a mounting surface which supports a circuit board with at least one LED light source spaced thereon, and an optical member which has a back side having a groove facing the mounting surface and surrounding the circuit board. The groove is filled with a resilient in-situ-formed compressible gasket material sealingly engaged with the mounting surface to environmentally seal the circuit board. The mounting surface may be of a heat-sink structure. The in-situ-formed gasket has an inner edge and a plurality of inward projections spaced therealong. Each inward projection extends inwardly to a position facing the circuit board and presses the circuit board against the mounting surface, thereby facilitating heat transfer away from the circuit board.

Claims

1. An LED light fixture comprising:

a mounting surface supporting a plurality of LED light sources; and

an optical member having a back side facing the mounting surface and having a groove with an inward edge surrounding the LED light sources and a plurality of spur-grooves, the groove and the spur-grooves being filled with a resilient compressible gasket sealingly engaged with the mounting surface, thereby environmentally sealing the LED light sources.

2. The LED light fixture of claim 1 further comprising:

a heat-sink structure including the mounting surface; and

a circuit board with the plurality of LED light sources thereon and supported by the mounting surface.

3. The LED light fixture of claim 2 wherein each spur-groove connects the groove to an injection gate spaced from an inward edge of the groove such that the gasket has an inner edge and a plurality of inward projections spaced therealong, each inward projection extending inwardly to a position facing the circuit board and pressing the circuit board against the mounting surface, thereby facilitating heat transfer away from the circuit board.

4. The LED light fixture of claim 3 wherein the inward projections are configured for enhanced pressing of the circuit board against the mounting surface of the heat-sink structure.

5. The LED light fixture of claim 4 wherein:

the circuit board has a front surface;

each of the inward projections faces the circuit-board front surface and has an enlarged mass which is spaced from the inner edge of the gasket and extends away from the optical-member back surface.

6. The LED light fixture of claim 3 wherein the inward projections are configured for enhanced pressing of the circuit board against the heat-sink structure.

7. The LED light fixture of claim 6 wherein:

the circuit board has a front surface;

each of the inward projections faces the circuit-board front surface and has an enlarged mass which is spaced from the inner edge of the gasket and extends away from the optical-member back side.

8. The LED light fixture of claim 1 wherein each spur-groove connects the groove to an injection gate spaced from an inward edge of the groove such that the gasket has an inner edge and a plurality of inward projections spaced therealong.

9. The LED light fixture of claim 1 wherein the gasket material is a thermoplastic elastomer (TPE).

10. A method for manufacturing an optical member for an LED light fixture of the type including a mounting surface supporting at least one LED light source and the optical member, the method comprising the steps of:

providing an optical-member carrier piece with a back side for facing the mounting surface, the back side having a groove positioned to surround the at least one LED light source, the groove including a plurality of spur-grooves extending inwardly from an inner edge of the groove; and

forming a resilient compressible gasket with a plurality of inward projections therealong by injecting a thermoplastic elastomer (TPE) into the groove and the spur-grooves.

11. The method of claim 10 wherein the light fixture further includes a circuit board with the at least one LED light source thereon and supported by the mounting surface.

12. The method of claim 11 wherein the inward projections extend inwardly to be positioned facing the circuit board.

13. The method of claim 11 wherein:

each spur-groove terminates with a distal end which is spaced from an inner edge of the gasket; and

injection gates are at the distal ends of the spur-grooves.

14. A method for manufacturing an optical member for at least one LED light source supported with respect to a mounting surface, the method comprising:

providing a groove and a plurality of spur-grooves formed in an optical-member back side positionable to face the mounting surface, the groove being configured to surround the at least one LED light source and the spur-grooves which extend inwardly from the groove to terminate with a distal end which is spaced from an inner edge of the groove; and

injecting a thermoplastic elastomer (TPE) into the groove through injection gates which are at the distal ends of the spur-grooves.

15. The method of claim 14 further including a step of forming an enlarged mass at each of the injection gates, the formed mass extending away from the optical-member back side.

16. An LED light fixture comprising:

a mounting surface supporting at least one LED light source; and

an optical member having a back side facing the mounting surface and having a lens corresponding to the at least one light source, the back side having a groove surrounding the at least one LED light source and at least one spur-groove extending inwardly from an inner edge of the groove, the groove and the at least one spur-groove being filled with a resilient compressible gasket.

17. The LED light fixture of claim 16 further comprising:

a heat-sink structure including the mounting surface; and

a circuit board with the at least one LED light source thereon and supported by the mounting surface.

18. The LED light fixture of claim 17 wherein the gasket has an inner edge and a plurality of inward projections spaced therealong, each inward projection extending inwardly to a position facing the circuit board and pressing the circuit board against the mounting surface, thereby facilitating heat transfer away from the circuit board.

19. The LED light fixture of claim 18 wherein the inward projections are configured for enhanced pressing of the circuit board against the mounting surface of the heat-sink structure.

20. The LED light fixture of claim 19 wherein:

the circuit board has a front surface;

the at least one inward projection faces the circuit-board front surface and has an enlarged mass which is spaced from the inner edge of the gasket and extends away from the optical-member back surface.

21. The LED light fixture of claim 16 wherein each spur-groove connects the groove to an injection gate spaced from an inward edge of the groove.

22. The LED light fixture of claim 16 wherein the gasket material is a thermoplastic elastomer (TPE).