Patent Application
20120152226
The present invention provides a heat sink for LEDs or other electronic elements in a kitchen appliance.
Modern kitchen appliances are frequently provided with various features that rely upon electronics for operation. For example, a range hood or oven may include a processing device mounted on a printed circuit board (PCB) and connected with a touch panel or other device whereby the user may select various options for operation of the appliance. For an oven, such PCB might include different, user selectable cooking algorithms based on the food and/or mode of cooking desired. The PCB typically associated with such features is electrically-powered and generates heat during operation. If the PCB becomes too hot, the electronics may cease to operate properly or even become permanently damaged.
Some appliances may also be equipped with lighting features that rely upon light emitting diodes (LEDs) to provide illumination. For example, a range hood or an over the range microwave oven may include various LED bulbs to light up a cook top. Such lighting may be important to the user as the cook top will typically have several heating elements positioned on a horizontal surface for cooking food contained in pots and pans.
For these applications, LED lighting has certain advantages as compared to incandescent or other types of lights. These advantages can include e.g., resistance to vibration, long life expectancy, relatively low energy use, durability for repeated on-off switching, and compactness. In addition, where more light is needed, LED bulbs can be grouped together to increase the intensity of the light output.
However, there are certain challenges to using LED lamps in a kitchen appliance. As with a PCB, LED lamps can produce a significant amount of heat and are susceptible to poor operation if their temperature rises too high. More particularly, there is generally a narrow range of temperatures at which LED lamps can efficiently produce their maximum light output or most efficient light output. In addition, if the temperature elevates above a certain range, the LEDs can be damaged or even destroyed.
As such, an appliance must provide for properly cooling electronics and LED lamps during operation. Such can be a difficult task with a kitchen appliance because of the heat that is generated from cooking. For example, LED lamps are sometimes provided in a range hood to provide lighting above the cook top. Heat coming from the cook top and/or an associated oven will rise up and through the range hood. Depending upon the placement of the LED lamps, this heat can provide further temperature problems for LED lamps by advancing the temperature increase. Similar problems can be created for a PCB or other electronics if positioned where they can be affected by heat from cooking.
Accordingly, a system for the effective cooling of LED lamps or other electronics in a kitchen appliance would be useful. A system that can use structural and other features of the appliance to facilitate such cooling would be beneficial. Such a system that can be readily incorporated within the overall design of an appliance would also be very useful.
Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
In one exemplary aspect of the present invention, a method for cooling an electronic component in a kitchen appliance is provided. The method includes the steps of selecting a position on the kitchen appliance that will facilitate the conduction of heat away from the electronic component; placing the electronic component in thermal contact with the kitchen appliance at such position; and conducting heat from the electronic component to the appliance.
In another exemplary embodiment, the present invention provides a kitchen appliance. The appliance includes an electronic component providing one or more features for the appliance and a heat conducting element that forms part of the kitchen appliance. The electronic component is thermally connected with the heat conducting element such that heat generated by the electronic component is conducted to the heat conducting element.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
The present invention provides a heat sink for LEDs or other electronic elements in a kitchen appliance. The chassis or other heat conducting components of the appliance are used as a heat sink to conduct away heat. The LEDs or other electronic features may be connected directly to the heat sink or may be connected by e.g., a bracket.
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
During operation of oven 18, heat and cooking fumes are generated from heating elements 16 and/or the baking or broiling in the cavity. This heat will rise upwardly, towards range hood 10. As such, at least some of the heat from cooking operations will heat range hood 10 and its associated lighting and other electronic features.
In the configuration shown, LED lamp 30 provides light for the illumination of cook-top surface 14 on range 12. More specifically, LED lamp 30 provides light through an opening 44 in an upper appearance panel 32. Additional openings can be provided for other LED lamps positioned in range hood 10 as desired.
A typical LED lamp can provide more light, and is more efficient at producing light, as temperature decreases. During operation of LED lamp 30, it will generate a significant amount of heat that can be deleterious to its proper functioning. In addition, the heat generated from cooking with oven 18 further exacerbates the problem by providing additional heat that can adversely affect LED lamp 30.
Accordingly, LED lamp 30 is in thermal contact with a mounting panel 34, which forms part of the frame or chassis 46 of range hood 10. As shown in
Mounting panel 34 is positioned behind upper appearance panel 32. More particularly, with respect to the flow of heat rising upwardly from oven 18, panel 34 is shielded from such heat by upper appearance panel 32. As such, mount panel 34 is protected from the heat generated by cooking so as to improve its ability to conduct heat away from LED lamp 30.
In addition, range hood 10 is constructed in a manner that uses natural convection to help further cool LED lamp 30. Chassis 46 and vent duct 24 form a chamber 48. As LED lamp 30 heats up during operation and, in turn, conducts heat to mounting panel 34, air within chamber 48 near the surface of mounting panel 34 will be heated. The heated air will then rise within chamber 48 to be displaced by cooler air falling down to replace the heated air. This process of natural convection further contributes to the cooling of LED lamp 30.
Additionally, the placement of LED lamp 30 can be controlled to further improve the cooling effects of mounting it to panel 34. More specifically, the placement of LED lamp 30 along upper appearance panel 32 can be selected such that lamp 30 is not directly over a heat source from oven 18 such as one of the heating elements 16. The size of range hood 10, i.e., the extent to which hood 10 projects out and over appliance 18 can also be increased in order to move LED lamp 30 further away from a position directly above heat sources in oven 18.
By positioning LED lamp 30 directly into contact with vent duct 24, heat generated during operation of lamp 30 can be conducted directly to vent duct 24. By constructing vent duct 24 from a conductive material such as a metal, heat conducted from LED lamp 30 is turn conducted along vent duct 24, which in turn helps cool lamp 30. In addition, during operation of range 12, the user may activate fan 26 to draw heat and cooking fumes away from range 12 and to an exhaust as shown by arrows A. The movement of air through vent duct 24 will also help cool vent duct 24 and improve its efficiency as a heat sink for LED lamp 30. As previously described, chamber 48 will also contribute to the cooling of LED lamp 30 through natural convection.
The above exemplary embodiments of the present invention were described using LED lamp 30. As will be understood by one of ordinary skill in the art using the teachings disclosed herein, the same principles can be used to provide for the cooling of a PCB or other electronics that need protection from heat. For example, the PCB could be attached to mounting panel 34 or other parts of the chassis 46 of range hood 10 for the conduction of heat away from the PCB. Similarly, the PCB could be attached to vent duct 24 to conduct heat away from the PCB in a manner as described above with regard to LED lamp 30. With both a PCB or LED lamp 30, it should be understood that such may be directly connected to a heat sink such as chassis 46 as shown in
As will be understood by one of skill in the art using the teachings herein, the present invention may be used with other appliances as well and is not limited to a range hood. For example, similar constructions may be used to provide cooling for the electronics found in an oven, a microwave mounted over cook-top surface, and still other appliances as well. In addition, the LED or PCB can be connected to other parts of the appliance that can operate as a heat sink, and the present invention is not limited to the configurations shown in the figures. As such, it should be understood that this written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
