LED Lighting Fixture

Information

  • Patent Application
  • 20140104835
  • Publication Number
    20140104835
  • Date Filed
    March 15, 2013
    11 years ago
  • Date Published
    April 17, 2014
    10 years ago
Abstract
An LED lighting fixture including a housing and an LED assembly secured with respect to the housing to permit air/water-flow over the LED assembly. The LED assembly includes a plurality of LED-array modules on an equal plurality of individual heat sinks. The housing defines an air gap permitting air/water-flow to and from the heat sinks.
Description
FIELD OF THE INVENTION

This invention relates to lighting fixtures and, more particularly, to lighting fixtures using light-emitting diodes (LEDs).


BACKGROUND OF THE INVENTION

In recent years, the use of LEDs for various common lighting purposes has increased, and this trend has accelerated as advances have been made in LEDs and in LED arrays, often referred to as “LED modules.” Indeed, lighting applications which previously had been served by fixtures using what are known as high-intensity discharge (HID) lamps are now beginning to be served by fixtures using LEDs. Such lighting applications include, among a good many others, roadway lighting, factory lighting, parking lot lighting, and commercial building lighting.


Lighting fixtures using LEDs as light source for various applications present particularly challenging problems in fixture development, particularly when fixture mounting locations vary. Among other things, placement of the electronic LED power units (LED drivers) for lighting fixtures using LED arrays can be particularly problematic. In some cases, keeping such electronic LED drivers in a air/water-tight location may not be difficult, but if mounting locations and structures vary, then location and protection of such components becomes difficult and adds development costs and potential problems. Lighting-fixture adaptability is an important goal for LED lighting fixtures that are often presented.


Heat dissipation is another problem for LED lighting fixtures. And, the goals of dealing with heat dissipation and protection of electronic LED drivers can often be conflicting, contrary goals.


In short, there is a significant need in the lighting industry for improved lighting fixtures using LED units—fixtures that are adaptable for a wide variety of mountings and situations, and that satisfy the problems associated with heat dissipation and appropriate protection of electronic LED driver components. Finally, there is a need for an improved LED-based lighting fixture which is easy and inexpensive to manufacture.


SUMMARY OF THE INVENTION

The present invention is an improvement in LED lighting fixtures. The inventive LED lighting fixture includes a housing forming a substantially air/water-tight chamber, at least one electronic LED driver enclosed within the chamber, and an LED assembly secured with respect to the housing adjacent thereto in non-air/water-tight condition, the LED assembly having at least one LED-array module mounted on an LED heat sink.


The housing preferably includes substantially air/water-tight wire-access(es) for passage of wires between the LED assembly and the air/water-tight chamber.


The housing includes a first border structure forming a first border-portion of the chamber, the first border structure receiving wires from the at least one LED-array module and the LED heat sink being interlocked with the first border structure. The housing further includes a frame structure forming a frame-portion of the chamber secured to the first border structure, the frame structure extending along the LED assembly. It is preferred that the border structure be a metal extrusion.


In some preferred embodiments, the first border structure has at least one bolt-receiving border-hole through the first border structure, such border-hole being isolated from the first border-portion of the chamber. The frame structure also has at least one bolt-receiving frame-hole through the frame structure, the frame-hole being isolated from the frame-portion of the chamber. Each such one or more frame-holes are aligned with a respective border-hole(s). A bolt passes through each aligned pair of bolt-receiving holes such that the border structures and the frame structure are bolted together while maintaining the air/water-tight condition of the chamber.


In some highly preferred embodiments, the housing includes a second border structure forming a second border-portion of the chamber, the LED heat sink being interlocked with the second border structure. In such embodiments, the frame structure is secured to the first and second border structures.


The frame structure preferably includes an opening edge about the frame-portion of the chamber. A removable cover-plate is preferably in substantial wate/air-tight sealing engagement with respect to the opening edge. Such opening edge may also have a groove configured for mating air/water-tight engagement with the border structure(s). It is preferred that one or more electronic LED drivers be enclosed in the frame-portion of the chamber.


In certain preferred embodiments the frame structure preferably includes a vent permitting air flow to and from the LED assembly. Such venting facilitates cooling of the LED assembly.


In certain highly preferred embodiments of this invention, including those used for street lighting and the like, the housing is a perimetrical structure such that the substantially air/water-tight chamber substantially surrounds the LED assembly. The perimetrical structure is preferably substantially rectangular and includes the first and second border structures and a pair of opposed frame structures each secured to the first and second border structures.


In some versions of the inventive LED lighting fixture, the housing is a perimetrical structure configured for wall mounting and includes the first and second border structures on opposed perimetrical sides and the frame structure secured on a perimetrical side between the border structures.


In such embodiments, each of the first and second border structures preferably has at least one bolt-receiving border-hole therethrough isolated from the first and second border-portion of the chamber, respectively. Each of the frame structures has at least one bolt-receiving frame-hole therethrough isolated from the frame-portion of the chamber, each such frame-holes aligned with respective border-holes of each of the border structures. A bolt is passing through each aligned set of bolt-receiving holes such that the border structures and the frame structures are bolted together while maintaining the air/water-tight condition of the chamber.


In certain highly preferred embodiments of the inventive LED lighting fixture, the LED assembly includes a plurality of LED-array modules each separately mounted on its corresponding LED heat sink, the LED heat sinks being interconnected to hold the LED-array modules in fixed relative positions. Each heat sink preferably includes a base with a back base-surface, an opposite base-surface, two base-ends and first and second base-sides. A female side-fin and a male side-fin each extends along one of the opposite base-sides and each protrudes from the opposite base-surface to terminate at a distal fin-edge. The female side-fin includes a flange hook positioned to engage the distal fin-edge of the male side-fin of an adjacent heat sink. At least one inner-fin projects from the opposite surface between the side-fins. One of the LED modules is against the back surface.


In some preferred embodiments, each heat sink includes a plurality of inner-fins protruding from the opposite base-surface. Each heat sink may also include first and second lateral supports protruding from the back base-surface, the lateral supports each having an inner portion and an outer portion. The inner portions of the first and second lateral supports have first and second opposed support-ledges, respectively, forming a heat-sink-passageway slidably supporting one of the LED-array modules against the back base-surface. The first and second supports of each heat sink are preferably in substantially planar alignment with the first and second side-fins, respectively. The flange hook is preferably at the distal fin-edge of the first side-fin.


It is highly preferred that each heat sink be a metal extrusion with the back base-surface being substantially flat to facilitate heat transfer from the LED-array module, which itself has a flat surface against the back-base surface.


Each heat sink also preferably includes a lateral recess at the first base-side and a lateral protrusion at the second base-side, the recesses and protrusions being positioned and configured for mating engagement of the protrusion of one heat sink with the recess of the adjacent heat sink.


In certain of the above preferred embodiments, the female and male side-fins are each a continuous wall extending along the first and second base-sides, respectively. It is further preferred that the inner-fins are also each a continuous wall extending along the base. The inner-fins can be substantially parallel to the side-fins.


In highly preferred embodiments, the LED lighting fixture further includes an interlock of the housing to the LED assembly. The interlock has a slotted cavity extending along the housing and a cavity-engaging coupler which extends from the heat sink of the LED assembly and is received within the slotted cavity.


In some of such preferred embodiments, in each heat sink, at least one of the inner-fins is a middle-fin including a fin-end forming a mounting hole receiving a coupler. In some versions of such embodiments, the coupler has a coupler-head; and the interlock is a slotted cavity engaging the coupler-head within the slotted cavity. The slotted cavity preferably extends along the border structure and the coupler-head extends from the heat sink of the LED assembly.


In preferred embodiments of this invention, the LED lighting fixture includes a restraining bracket secured to the housing. The bracket has a plurality of projections extending between adjacent pairs of fins of the heat sink, thus to secure the LED assembly. The restraining bracket preferably has a comb-like structure including an elongated body with a spine-portion from which identical side-by-side projections extend in a common plane. Such restraining bracket is configured and dimensioned for the elongated body to be fixedly secured to the housing and the projections to snugly fit in spaces between adjacent heat-sink fins, thus holding heat sink from moving.


The LED lighting fixture further includes a mounting assembly secured to the housing. The mounting assembly preferably has a pole-attachment portion and a substantially air/water-tight section enclosing electrical connections with at least one wire-aperture communicating with the air/water-tight chamber. The housing is in air/water-tight engagement with the air/water-tight section of the pole-mounting assembly.


In the aforementioned substantially rectangular versions of this invention, in which the perimetrical structure includes a pair of opposed frame structures and a first second opposed border structures, the second border structure may have two sub-portions with a gap therebetween. The sub-portions each include all of the border-structure elements.


In the mounting assembly of such embodiments, the pole-attachment portion preferably receives and secures a pole. Each wire-aperture communicates with the border-portion chamber of a respective one of the second border-structure sub-portions. The gap between the second border-structure sub-portions accommodates the pole-mounting assembly secured to the LED assembly between the border sub-portions. The second border-structure sub-portion(s) are in air/water-tight engagement with the air/water-tight section of the pole-mounting assembly. The pole-attachment portion preferably includes grooves on its opposite sides, the grooves being configured for mating engagement with end edges of the border-structure sub-portions.


Preferably, the pole-mounting assembly has a mounting plate abutting the LED assembly, and at least one fastener/coupler extends from the mounting plate for engagement with the mounting hole of the middle-fin(s).


In some LED lighting fixtures of this invention, the frame-portion of the chamber has a chamber-divider across the chamber, such chamber-divider having a divider-edge. The chamber-divider divides the frame-portion of the chamber into an end part and a main part that encloses the electronic LED driver(s). The chamber-divider preferably includes a substantially air/water-tight wire-passage therethrough. The wire-passage is preferably a notch having spaced notch-wall ends that terminate at the divider-edge. A notch-bridge spans the notch to maintain the air/water-tight condition of the chamber. The notch-bridge preferably includes a bridge-portion and a pair of gripping-portions configured for spring-grip attachment to the notch-wall ends. Preferably, the removable cover-plate seals the main part of the frame-portion of the chamber in substantially air/water-tight condition.


In certain embodiments of this invention, including those used for parking-structure lighting and the like, the frame structure is a sole frame structure, and the housing is a substantially H-shaped structure with the sole frame structure secured between mid-length positions of the pair of opposed border structures.


Some of the inventive LED lighting fixtures include a protective cover extending over the LED assembly and secured with respect to the housing. Such protective cover preferably has perforations permitting air/water-flow therethrough for access to and from the LED assembly.


It is most highly preferred that the LED lighting fixture has a venting gap between the housing and the LED assembly to permit air/water-flow from the heat sink. The venting gap may be formed by the interlock of the housing to the LED assembly.


The improved LED lighting fixture of this invention overcomes the problems discussed above. Among other things, the invention provides substantially air/water-tight enclosure of electronic LED drivers inside the fixture, while still accommodating heat-dissipation requirements. And, the fixture of this invention is both adaptable for varying applications and mountings, and relatively inexpensive to manufacture.


The term “perimetrical structure” as used herein means an outer portion of the fixture which completely or partially surrounds remaining portions of the fixture. In certain preferred embodiments, such as those most useful for road-way lighting and the like, the perimetrical structure preferably completely surrounds remaining portions of the fixture. In certain other cases, such as certain wall-mounted lighting fixtures, the perimetrical structure partially surrounds the remaining portions of the fixture.


The term “ambient fluid” as used herein means air and/or water surrounding the lighting fixture.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a perspective view of a preferred LED lighting fixture in accordance with this invention, including a cut-away portion showing an LED assembly.



FIG. 2 is a perspective view of the LED lighting fixture configured for wall mounting.



FIG. 3 is a perspective view of another LED lighting fixture including a pole-mounting assembly on a pole of square cross-section.



FIG. 4 is a side perspective view of the LED lighting of FIG. 1 broken away at a middle portion to show interior structure.



FIG. 5 is a front perspective view of the LED lighting of FIG. 1 broken away at a middle portion to show interior structure.



FIG. 6 is a fragmentary view of the right portion of FIG. 4.



FIG. 7 is another fragmentary perspective view showing the frame structure partially cut-away view to illustrate its being bolted together with the border structure.



FIG. 8 is another fragmentary perspective view showing the border structure partially cut-away view to illustrate its engagement with the frame structure.



FIG. 9 is a greatly enlarged fragmentary perspective view showing a portion of the chamber-divider wall, the notch therein and the notch-bridge thereover.



FIG. 10 is a perspective view of one LED-array module LED and its related LED heat sink of the LED assembly of the illustrated LED lighting fixtures.



FIG. 11 is a perspective view of two interconnected LED heat sinks of the LED assembly of the illustrated LED lighting fixtures.



FIG. 12 is a fragmentary perspective view from below of the pole-mounting assembly engaged with a pole-attachment portion, with the cover of the pole-mounting assembly removed to show internal parts.



FIG. 13 is a perspective view of the LED lighting fixture of the type having the housing being a substantially H-shaped structure.



FIG. 14 is a top perspective view of another embodiment of the LED lighting fixture including a restraining bracket seen through a cut-away in the protective cover.



FIG. 15 is a perspective view of the restraining bracket of FIG. 14.





DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS


FIGS. 1-15 illustrate preferred LED lighting fixtures 10A-10D in accordance with this invention. Common or similar parts are given the same numbers in the drawings of both embodiments, and the lighting fixtures are often referred to by the numeral 10, without the A or D lettering used in the drawings, and in the singular for convenience.


Lighting fixture 10 includes a housing 12 that forms a substantially air/water-tight chamber 14, at least one electronic LED driver 16 enclosed within chamber 14 and an LED assembly 18 secured with respect to housing 12 adjacent thereto in non-air/water-tight condition. LED assembly 18 has a plurality of LED-array modules 19 each secured to an LED heat sink 20.


As seen in FIGS. 1-4, 7 and 8, housing 12 includes a frame structure 30 forming a frame-portion 32 of chamber 14 with an opening edge 34 thereabout and a border structure 40 (sometimes referred to as a nose structure 40) secured to frame structure 30 and forming a border-portion 42 (sometimes referred to as nose-portion 42) of chamber 14. As best seen in FIG. 8, opening edge 34 of frame-portion 30 of chamber 14 includes a groove 35 configured for mating air/water-tight engagement with border structure 40. Border structure 40 is an extrusion, preferably of aluminum. FIG. 5 shows electronic LED drivers 16 enclosed in frame-portion 32 of chamber 14.


As best seen in FIG. 6, border structure 40 includes substantially air/water-tight wire-accesses 44 for passage of wires 17 between LED assembly 18 and water/air-tight chamber 14.



FIGS. 2, 3, 5 and 7 show that frame structure 30 includes a vent 36 permitting air flow to and from LED assembly 18. Vent 36 facilitates cooling of LED assembly 18.


As best illustrated in FIGS. 6 and 7, border structure 40 has bolt-receiving border-hole 47 therethrough which is isolated from border-portion 42 of chamber 14. And, frame structure 30 has bolt-receiving frame-holes 37 therethrough which are isolated from frame-portion 32 of chamber 14; frame-hole 37 is aligned with a respective border-hole 47. A bolt 13 passes through aligned pair of bolt-receiving holes 37 and 47 such that border structure 40 and frame structure 30 are bolted together while maintaining the air/water-tight condition of chamber 14.



FIGS. 1 and 3 best illustrate certain highly preferred embodiments of this invention in which housing 12 is a perimetrical structure which includes a pair of opposed frame structures 30 and a pair of opposed nose structures 40, making perimetrical structure 12 of lighting fixture 10A substantially rectangular. FIGS. 1, 4-8 and 11 illustrate aspects of inventive LED lighting fixture 10A.


In LED lighting fixtures 10, LED assembly 18 includes a plurality of LED-array modules 19 each separately mounted on its corresponding LED heat sink 20, such LED heat sinks 20 being interconnected to hold LED-array modules 19 in fixed relative positions. Each heat sink 20 includes: a base 22 with a back base-surface 223, an opposite base-surface 224, two base-ends 225 and first and second base-sides 221 and 222; a plurality of inner-fins 24 protruding from opposite base-surface 224; first and second side-fins 25 and 26 protruding from opposite base-surface 224 and terminating at distal fin-edges 251 and 261, first side-fin 25 including a flange hook 252 positioned to engage distal fin-edge 261 of second side-fin 26 of adjacent heat sink 20; and first and second lateral supports 27 and 28 protruding from back base-surface 223, lateral supports 27 and 28 each having inner portions 271 and 281, respectively, and outer portion 272 and 282, respectively. Inner portions 271 and 281 of first and second lateral supports 27 and 28 have first and second opposed support-ledges 273 and 283, respectively, that form a heat-sink-passageway 23 which slidably supports an LED-array module 19 against back base-surface 223. First and second supports 27 and 28 of each heat sink 20 are in substantially planar alignment with first and second side-fins 25 and 26, respectively. As seen in FIGS. 10 and 11, the flange hook is at 251 distal fin-edge of first side-fin 25.


Each heat sink 20 is a metal (preferably aluminum) extrusion with back base-surface 223 of heat sink 20 being substantially flat to facilitate heat transfer from LED-array module 19, which itself has a flat surface 191 against back-base surface 223. Each heat sink 20 also includes a lateral recess 21 at first base-side 221 and a lateral protrusion 29 at second base-side 222, recesses 21 and protrusions 29 being positioned and configured for mating engagement of protrusion 29 of one heat sink 20 with recess 21 of adjacent heat sink 20.


As best seen in FIGS. 1, 4, 5, 6, 10 and 11, first and second side-fins 25 and 26 are each a continuous wall extending along first and second base-sides 221 and 222, respectively. Inner-fins 24 are also each a continuous wall extending along base 22. Inner-fins 24 are substantially parallel to side-fins 25 and 26.



FIGS. 4 and 6 show an interlock of housing 12 to LED assembly 18. As best seen in FIGS. 10 and 11, in each heat sink 20 inner-fins 24 include two middle-fins 241 each of which includes a fin-end 242 forming a mounting hole 243. A coupler 52 in the form of a screw is engaged in mounting hole 243, and extends from heat sink 20 to terminate in a coupler-head 521. Housing 12 has a slotted cavity 54 which extends along, and is integrally formed with, each of border structures 40 forms the interlock by receiving and engaging coupler-heads 521 therein.



FIG. 2 illustrates a version of the invention which is LED lighting fixture 10B. In lighting fixture 10B, perimetrical structure 12 includes a pair of nose structures 40 configured for wall mounting and one frame structure 30 in substantially perpendicular relationship to each of the two nose structures 40.


The substantially rectangular lighting fixture 10A which is best illustrated in FIGS. 1, 3 and 4, perimetrical structure 12 includes a pair of opposed frame structures 30 and a pair of opposed first nose structure 40 and second nose structure 41. The second nose structure 41 has two spaced sub-portions 41A and 41B with a gap 412 therebetween. Sub-portions 41A and 41B each include all of the nose-portion elements. Gap 412 accommodates a pole-mounting assembly 60, one embodiment of which is shown in FIGS. 1, 3, 4 and 12, that is secured to LED assembly 18 between nose sub-portions 41A and 41B.


Pole-mounting assembly 60 includes a pole-attachment portion 61 that receives and secures a pole 15 and a substantially air/water-tight section 62 that encloses electrical connections and has wire-apertures 64. Each wire-aperture 64 communicates with nose-portion 42 chamber of a respective one of nose-structure sub-portions 41A and 41B. Nose-structure sub-portions 41A and 41B are in air/water-tight engagement with air/water-tight section 62 of pole-mounting assembly 60. Air/water-tight section 62 includes grooves 621 on its opposite sides 622; grooves 621 are configured for mating engagement with end edges 413 of nose-structure sub-portions 41A and 41B.


As best seen in FIG. 12, pole-mounting assembly 60 has a mounting plate 65 abutting LED assembly 18, and fastener/couplers 66 extend from mounting plate 65 into engagement with mounting hole 243 of middle-fins 241.



FIGS. 8 and 9 show that frame-portion 32 of chamber 14 has a chamber-divider 33 across chamber 32 that divides frame-portion 32 of chamber 14 into an end part 321 and a main part 322, which encloses electronic LED driver(s) 16. Chamber-divider 33 has a divider-edge 331. Chamber-divider 33 includes a substantially air/water-tight wire-passage therethrough in the form of a notch 332 having spaced notch-wall ends 334 that terminate at divider-edge 331. A notch-bridge 38 spans notch 332 to maintain the air/water-tight condition of chamber 32. Notch-bridge 38 includes a bridge-portion 381 and a pair of gripping-portions 382 which are configured for spring-grip attachment to notch-wall ends 334. A removable cover-plate 31 seals main part 322 of frame-portion 32 of chamber 14 in substantially air/water-tight condition.



FIGS. 2-6 show that inventive LED lighting fixtures 10 include a protective cover 11 that extends over LED assembly 18 and is secured with respect to housing 12. Protective cover 11 has perforations 111 to permit air and water flow therethrough for access to and from LED assembly 18.


As best seen in FIGS. 5 and 6, LED lighting fixture 10 has a venting gap 56 between housing 12 and LED assembly 18, to permit air and water flow from heat sink 20. Venting gap 56 is formed by the interlock of housing 12 to LED assembly 18 or is a space along outer side-fins of the LED assembly.



FIG. 13 shows an embodiment of the inventive lighting fixture 10C in which frame structure 30C is a sole frame structure, and housing 12C is a substantially H-shaped structure with sole frame structure 30C secured between mid-length positions of the pair of opposed border structures 40C.



FIG. 14 shows another embodiment of the inventive LED lighting fixture 10D with housing 12D formed by a pair of opposed border structures 40 and LED assembly 18 secured between border structures 40. Lighting fixture 10D, as shown on FIG. 14, includes a restraining-bracket 80 secured to housing 12D by screws 85 through screw-holes 87. Bracket 80 has a plurality of projections 82 each of which extends between adjacent fins of two of heat sinks 20. Restraining bracket 80, best shown on FIG. 15, is a comb-like structure with an elongated body 84 including a spine-portion 86 from which the plurality of projections 82 extend. Restraining-bracket 80 is configured and dimensioned for elongated body 84 to be fixedly secured to housing 12 and for projections 82 to snugly fit in spaces between adjacent heat-sink fins.


While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting.

Claims
  • 1. An LED lighting fixture comprising a housing and an LED assembly secured with respect to the housing such that the LED assembly is open to air and water, the LED assembly including a plurality of LED-array modules on an equal plurality of individual heat sinks, the housing defining an air gap permitting air/water-flow to and from the heat sinks.
  • 2. The LED lighting fixture of claim 1 wherein the heat sinks are separate structures connected with respect to the housing.
  • 3. The LED lighting fixture of claim 2 further including at least one connection device holding adjacent pairs of the individual heat sinks with respect to one another.
  • 4. The LED lighting fixture of claim 3 wherein the connection device is integral with at least one of the adjacent heat sinks.
  • 5. The LED lighting fixture of claim 4 wherein the connection device holds the adjacent heat sinks in side-by-side relationship to one another.
  • 6. The LED lighting fixture of claim 1 wherein: the housing defines a closed chamber; andat least one electronic driver is within the chamber.
  • 7. The LED lighting fixture of claim 1 further including a protective cover extending over the LED assembly and secured with respect to the housing, the protective cover having perforations permitting air/water-flow therethrough.
  • 8. The LED lighting fixture of claim 1 wherein the housing is a perimetrical structure with first and second border structures being on opposed perimetrical sides of the LED assembly and a frame structure is secured on a perimetrical side between the border structures.
  • 9. The LED lighting fixture of claim 8 wherein the perimetrical structure is substantially rectangular and includes a pair of opposed frame structures each connected to the first and second border structures.
  • 10. The LED lighting fixture of claim 8 wherein each heat sink has two heat-sink ends, one heat-sink end being at the first border structure and the other heat-sink end being at the second border structure.
  • 11. The LED lighting fixture of claim 10 wherein the venting gap is between at least one of the heat-sink ends and the corresponding border structure.
  • 12. The LED lighting fixture of claim 1 wherein each heat sink is an extrusion having a module-engaging surface and a heat-dissipating surface.
  • 13. The LED lighting fixture of claim 12 wherein, in each heat sink, the heat-dissipating surface includes at least one fin protruding therefrom.
  • 14. The LED lighting fixture of claim 13 further including at least one connection device holding adjacent pairs of the individual heat sinks with respect to one another.
  • 15. The LED lighting fixture of claim 14 wherein the connection device is integral with at least one of the adjacent heat sinks.
  • 16. The LED lighting fixture of claim 14 wherein the connection device holds the adjacent heat sinks in side-by-side relationship to one another.
RELATED APPLICATION

This application is a continuation of patent application Ser. No. 13/294,459, filed Nov. 11, 2011, which is a continuation of patent application Ser. No. 12/629,986, filed Dec. 3, 2009, now U.S. Pat. No. 8,070,306, issued Dec. 6, 2011, which is a continuation of patent application Ser. No. 11/860,887, filed Sep. 25, 2007, now U.S. Pat. No. 7,686,469, issued Mar. 30, 2010, which is a continuation-in-part of now abandoned patent application Ser. No. 11/541,908, filed Sep. 30, 2006. The entire contents of each of the parent applications are incorporated herein by reference.

Continuations (3)
Number Date Country
Parent 13294459 Nov 2011 US
Child 13834525 US
Parent 12629986 Dec 2009 US
Child 13294459 US
Parent 11860887 Sep 2007 US
Child 12629986 US
Continuation in Parts (1)
Number Date Country
Parent 11541908 Sep 2006 US
Child 11860887 US