WO2009079209A1

WO2009079209A1 - Inductively powered light assembly

Info

Publication number: WO2009079209A1
Application number: PCT/US2008/085368
Authority: WO
Inventors: Robert Dam; Karl S. Morgan; Michael W. Hartley; Barton C. Potter; Jeffrey L. Prunty; Marco Sclip
Original assignee: Illinois Tool Works Inc.
Priority date: 2007-12-17
Filing date: 2008-12-03
Publication date: 2009-06-25

Abstract

The present invention provides an inductively powered light assembly for use with appliances, such as refrigerators. More specifically, an embodiment of the present invention includes a light assembly (120) which attaches to the underside of the front edge of the shelf structure (110). A primary coil (122) is located within the refrigerator cabinet (100) and in close proximity to a secondary coil (124), which is located on the shelf assembly (110). As a result of inductive power transfer, power is wirelessly transferred from the primary coil (122) to the secondary (124) coil which illuminates the lights on the shelf. This inductively powered light assembly allows users to be able to remove or reposition shelving without having to activate or reactivate the power system.

Description

INDUCTIVELY POWERED LIGHT ASSEMBLY

CROSS REFERENCE TO RELATED APPLICATION

[001] This Non-Provisional Application claims benefit to United States Provisional Application Serial No. 61/014,213 on December 17, 2007.

FIELD OF THE INVENTION

[002] The present invention relates generally to a light assembly, and more particularly, to light assemblies for appliances, such as refrigerators.

BACKGROUND OF THE INVENTION

[003] Lights in a refrigerator are typically mounted to the interior back wall and/or ceiling of the refrigerator compartment. Others are installed into plastic housings that are mounted to either the back wall and/or ceiling of the refrigerator compartment. While these configurations provide ample light when the refrigerator is empty (e.g., on the showroom floor), the illumination is sub par when goods are placed on the shelves. Light is blocked and shadows are cast by the items on the shelves. An ideal location for mounting a refrigerator light would be on the underside of the front edge of a shelf. This light would illuminate the contents of the shelf below from front to back providing light in close approximation to the user's line of sight.

[004] The problem with this mounting configuration is getting electrical power to the light. Refrigerator shelves are typically adjustable in position, i.e., they can be moved either up or down by the user to create the optimal storage space. They can also be removed entirely from the refrigerator for cleaning. Since the shelves are movable and removable, hardwiring a light to the shelf is not practical.

[005] The present invention is directed at overcoming these and other known problems and disadvantages. SUMMARY OF THE INVENTION

[006] The present invention provides an inductively powered light assembly for use with appliances, such as refrigerators. More specifically, an embodiment of the present invention includes a light assembly which attaches to the underside of the front edge of the shelf structure. A primary coil is located within the refrigerator cabinet and in close proximity to a secondary coil, which is located on the shelf assembly. As a result of inductive power transfer, power is wirelessly transferred from the primary coil to the secondary coil which illuminates the lights on the shelf. This inductively powered light assembly allows users to remove or reposition shelving without having to activate or reactivate the power system.

[007] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.

BRIEF DESCRIPTION OF THE DRAWINGS

[008] Figure 1 is a perspective view of a refrigerator cabinet of an embodiment of an inductively powered light assembly.

[009] Figure 2A is an exploded perspective view of a refrigerator shelf of the light assembly in accordance with an embodiment of the invention.

[0010] Figure 2B is a top perspective view of the refrigerator shelf from Figure 2A. [0011] Figure 2C is a front plan view of the refrigerator shelf from Figure 2A.

[0012] Figure 2D is a bottom perspective view of the refrigerator shelf from Figure 2A.

[0013] Figure 3A is a top perspective view of a refrigerator shelf of the light assembly in accordance with an embodiment of the invention.

[0014] Figure 3B is a front plan view of the refrigerator shelf from Figure 3 A. [0015] Figure 3 C is a bottom perspective view of the refrigerator shelf from Figure

3A.

[0016] Figure 4 is an exploded perspective view of the light assembly in accordance with the embodiment from Figure 2A.

[0017] Figure 5A is exploded perspective view of a refrigerator shelf of the light assembly in accordance with an embodiment of the invention.

[0018] Figure 5B is a front plan view of the refrigerator shelf from Figure 5A.

[0019] Figure 5C is a bottom perspective view of the refrigerator shelf from Figure 5A.

[0020] Figure 6 is a bottom exploded perspective view of a refrigerator shelf of the light assembly in accordance with an embodiment of the invention.

[0021] Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of "including" and "comprising" and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] Exemplary aspects of an inductively powered light assembly are depicted in various views in Figures 1-6. Referring to Figure 1, a refrigerator cabinet 100 is depicted with a shelf 110. The interior space of the refrigerator cabinet 100 may be defined by a liner 101. The liner 101 may separate the interior space of the refrigerator cabinet 100 from the insulation material (not shown). The liner 101 may include an inner side 101a and an outer side 101b. The inner side of the liner 101a forms the interior wall of the refrigerator cabinet 100 and the outer side of the liner 101b faces the insulation material. A refrigerator is depicted in the figures and described throughout, however, other appliances which require lighting and may need or use shelves may be substituted in place of the refrigerator.

[0023] The shelf 110 includes two shelf supports 112, a front edge 114, a rear edge 117, and two lateral edges 116. Figure 1 also depicts a light assembly 120 of the present invention which includes a primary coil 122. The primary coil 122 may be generally flat, narrow and elongated. The primary coil 122 may be mounted to the outer side of the liner 101b in a vertical orientation. However, the primary coil 122 can be mounted to the outer side of the liner 101b in a non-vertical orientation and can be mounted to the inner side of the liner 101a as well. The primary coil 122 is electrically connected to a power supply circuit 102 as depicted in Figure 1. The power supply circuit 102 may be connected directly to an external power supply or also a power supply internal to the refrigerator cabinet 100.

[0024] Figures 2A-2D depict an embodiment of the invention wherein a light assembly 120 includes a secondary coil 124. Figure 2A depicts an exploded view of the shelf 110 and the light assembly 120. As is shown in Figure 2A, the light assembly 120 further includes the secondary coil 124 and a light tube assembly 130. The secondary coil 124 may be located within the light tube assembly 130 or may be attached directly to the shelf 110. The secondary coil 124 may be located along the front edge 114 of the shelf 110 and in close proximity to the interior wall of the refrigerator compartment 100 when the shelf 110 is installed. The primary coil's orientation and mounting will coincide closely with the position of the secondary coil 124 which is mounted to the installed shelf 110. The secondary coil 124 and primary coil 122 are in close proximity in order to help facilitate the inductive power transfer as described below.

[0025] The light tube assembly 130 may include features that allow the light tube assembly 130 to be affixed to the structure of the refrigerator shelf 110. Generally, the light tube assembly 130 may be attached to the underside of the front edge 114 of the shelf 110. However, the light tube assembly 130 may also be mounted to the underside of the lateral edges 116 or rear edges 117 of the shelf 110. The light tube assembly 130 is further explained below.

[0026] Figure 4 depicts an exploded view of the light tube assembly 130 attached to the shelf 110 As is shown in Figure 4, the light tube assembly 130 includes a tubular housing 132, an LED (or printed) circuit board 134, and a set of light emitting diodes ("LEDs") 136. The tubular housing 132 may consist of a length of clear or translucent plastic and include features that attach onto the shelf structure 110 near the front edge 114, lateral edge 116, or rear edge of the shelf 117. The tubular housing 132 may also include a hook feature 138 which can attach the light tube assembly 130 to the shelf 110. Alternatively, the shelf structure 110 may include other features for attaching the light tube assembly 130.

[0027] The LED circuit board 134 may be mounted within the tubular housing 132. The LED circuit board 134 may be narrow in order to fit within the tubular housing 132. The LED circuit board 134 may be approximately as long as the width of the shelf 110. If the light tube assembly 130 is mounted to the lateral edges 116 of the shelf 110, the LED circuit board 134 may be approximately as long as the length of the shelf 110.

[0028] Figures 3A-3C depict an alternate embodiment. Figures 3A-3C depict a light assembly 120 that includes the support circuitry on the LED circuit board 134. However, the secondary coil 124 is remotely mounted on one of the lateral edges 116 of the shelf 110.

[0029] The set of LEDs 136 may be mounted to the circuit board 134 within the tubular housing 132. The set of LEDs 136 may include a number of individual LEDs. The number of LEDs, the spacing of the LEDs, and the style of LEDs are a design choice as to providing the best light for the refrigerator or appliance. Other lighting sources, similar to LEDs may be used with this invention.

[0030] In operation, the light assembly 120 receives power through inductive coupling or inductive power transfer. As a result of inductive power transfer, power may be wirelessly transferred from a primary coil 122 in a power circuit supply to a secondary coil 124 in a secondary circuit. The transfer of power takes place by electromagnetic coupling through a process known as mutual induction. The primary coil 122 will be positioned proximate to the secondary coil 124 in order to successfully transfer power inductively.

[0031] With this invention, the primary coil 122 resides within the refrigerator cabinet 100 and the secondary coil 124 resides with the shelf assembly 110. In one embodiment, the primary coil 122 is mounted to the outer side of the liner 101b. The power supply circuit 102 may be electrically connected to the primary coil 122. The power supply circuit 102 may be connected directly to an external power supply or also a power supply internal to the refrigerator cabinet. The primary coil 122 will coincide closely with the position of the secondary coil 124 mounted to the installed shelf 110 in order to inductively transfer power. The secondary coil 124 may be mounted and electrically connected to the LED circuit board 134. Also, the secondary coil 124 may be in close proximity to the interior wall of the refrigerator cabinet 100 in order to remain proximate to the primary coil 122. Thereby, the power is inductively transferred from the primary coil 122 to the secondary coil 124. The secondary coil 124 then transfers power to the LED circuit board 134 which in turn then powers and illuminates the LEDs 136 in order to illuminate the interior of the refrigerator 110.

[0032] Figures 5A-5C depict an alternate embodiment of the invention. Figures 5A-5C depict a light assembly 120 that includes the LED circuit board 134. In this embodiment, the secondary coil 124 and its support circuitry are mounted on an auxiliary circuit board 125 which is mounted on one of the lateral edges of the shelf 110. The secondary coil 124 may be electrically connected to the auxiliary circuit board 125 instead of the LED circuit board 134. In this embodiment, the primary coil 122 resides within the refrigerator cabinet 100 and the secondary coil 124 resides with the shelf assembly 110. In one embodiment, the primary coil 122 is mounted to the outer side of the liner 101b. The power supply circuit 102 may be electrically connected to the primary coil. The power supply circuit 102 may be connected directly to an external power supply or also a power supply internal to the refrigerator cabinet 100. The primary coil 122 will coincide closely with the position of the secondary coil 124 mounted to the installed shelf 110 in order to inductively transfer power. The secondary coil 124 may be mounted and electrically connected to the auxiliary circuit board 125 which is in close proximity to the interior wall of the refrigerator cabinet 100 in order to remain proximate to the primary coil 122. The auxiliary circuit board 125 may be electrically connected to the printed circuit board 134. Thereby, the power is inductively transferred from the primary coil 122 to the secondary coil 124. The secondary coil 124 then transfers power to the auxiliary circuit board 125 which transfer power to the LED circuit board 134. The LED circuit board 134 then powers and illuminates the LEDs 136 in order to illuminate the interior of the refrigerator 100. Regardless of the configuration, the position of the secondary coil 124 is along the lateral edge 116 of the shelf 110 and in close proximity to the interior of the wall of the refrigerator cabinet 100 when the shelf 110 is installed.

[0033] An alternate embodiment, as depicted in Figure 6, includes a shelf 110 which has an integral light assembly 220. In this embodiment, the integral light assembly 220 is part of the shelf 110. The integral light assembly- 220 may be located on the underside of the front edge 114 of the shelf 110. The integral light assembly 220 may also be located on the lateral edges 116 of the shelf 110 or the rear edge of the shelf 117. An LED circuit board 134 may be mounted within the integral light assembly 220. The LED circuit board 134 may be narrow in order to fit within the integral light assembly. The LED circuit board 134 may be approximately as long as the width of the shelf 110. If the integral light assembly 220 is mounted to the lateral edges 116 of the shelf 110, the LED circuit board 134 may be approximately as long as the length of the shelf 110.

[0034] A set of LEDs 136 may be mounted to the LED circuit board 134 within the integral light assembly 220. The set of LEDs 136 may include a number of individual LEDs. The number of LEDs, the spacing of the LEDs, and the style of LEDs are a design choice as to providing the best light for the refrigerator or appliance. Other lighting sources, similar to LEDs may be used with this invention.

[0035] The light assembly 220 will operate properly regardless of the shelf s position within the interior of the refrigerator 100. Refrigerator shelves are typically adjustable in position. The shelf 100 can be moved either up or down by the user in order to create the optimal storage space within the refrigerator cabinet 100. The vertical orientation of the primary coil 122 within the refrigerator compartment 100 allows the primary coil 122 to couple with the secondary coil 124 near the lateral edge 116 of the shelf 110 even as the secondary coil 124 moves up or down depending on the shelf s position in the refrigerator 100.

[0036] The wireless, inductively powered, light assembly 120 provides a number of advantages over conventional hardwired lighting connections. The inductively powered light assembly 120 can reduce the chance of shock and can provide a relatively high level of electrical isolation between the power supply circuit 102 and the secondary coil or circuit 124. Inductively powered lighting also makes it easy for the user to move or remove the shelf 110 and avoid the need to make direct electrical connections, thus limiting the risk of exposure to electrical shock. The inductively powered light assembly 120 may also be more reliable since there is no mechanical interconnection to fail due to physical damage, oxidation, or contamination.

[0037] It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It is also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.

[0038] Various features of the invention are set forth in the following claims.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A light assembly for a shelf structure of an appliance, comprising: a primary coil connected to a power source; a secondary coil located within proximity to the primary coil; a light tube assembly, comprising: a tubular housing; a circuit board mounted in the tubular housing; a plurality of light emitting diodes mounted to the circuit board; and wherein the primary coil receives power from the power source and the primary coil transfers power to the secondary coil through inductive power transfer, the secondary coil is electrically connected to the circuit board which in turn powers and illuminates the light emitting diodes.

2. The light assembly of claim 1, wherein the primary coil is mounted to the outer side of an inner wall of the appliance in a substantially vertical orientation.

3. The light assembly of claim 1, wherein the primary coil is mounted to the inner side of an inner wall of the appliance in a substantially vertical orientation.

4. The light assembly of claim 1, wherein a vertical axis of the primary coil coincides with the position of the secondary coil.

5. The light assembly of claim 1, wherein the secondary coil is located along a lateral edge of the shelf structure.

6. The light assembly of claim 1, wherein the secondary coil is located along a rear edge of the shelf structure.

7. The light assembly of claim 1, wherein the secondary coil is located within the light tube assembly.

8. The light assembly of claim 1 , wherein the appliance is a refrigerator.

9. A light assembly for an adjustable position shelf structure of an appliance, comprising: a primary coil connected to a power source; a secondary coil positioned proximate to the primary coil wherein the secondary coil is mounted to an auxiliary circuit board; a light tube assembly mounted to the shelf, comprising: a tubular housing; a printed circuit board mounted in the tubular housing; a plurality of light emitting diodes mounted to the printed circuit board; and wherein the primary coil receives power from the power source and the primary coil transfers power to the secondary coil through inductive power transfer, the secondary coil is electrically connected to the auxiliary circuit board, and the auxiliary circuit board is electrically connected to the printed circuit board which in turn powers and illuminates the light emitting diodes.

10. The light assembly of claim 9, wherein the primary coil is mounted to the outer side of an inner wall of the appliance in a vertical position.

11. The light assembly of claim 9, wherein a substantially vertical axis of the primary coil coincides with the position of the secondary coil.

12. The light assembly of claim 9, wherein the secondary coil is located along a lateral edge of the shelf structure.

13. The light assembly of claim 9, wherein the tubular housing is mounted on the underside of a front edge of the shelf structure.

14. The light assembly of claim 9, wherein the circuit board is approximately as long as the width of the shelf structure.

15. The light assembly of claim 9, wherein the appliance is a refrigerator.

16. The light assembly of claim 9, wherein the tubular housing is mounted on the underside of a lateral edge of the shelf structure.

17. The light assembly of claim 9, wherein the tubular housing is mounted on the underside of a rear edge of the shelf structure.

18. A light assembly for a shelf structure of an appliance, comprising: a primary coil connected to a power source; a secondary coil located within proximity to the primary coil; a light tube integral to the shelf, comprising: a circuit board mounted in the shelf; a plurality of light emitting diodes mounted to the printed circuit board; and wherein the primary coil receives power from the power source and the primary coil transfers power to the secondary coil through inductive power transfer, the secondary coil is electrically connected to the circuit board which in turn powers and illuminates the light emitting diodes.

19. The light assembly of claim 18, wherein the primary coil is mounted to the outer side of an inner wall of the appliance in a substantially vertical position.

20. The light assembly of claim 18, wherein a substantially vertical axis of the primary coil coincides with the position of the secondary coil.