Patent Application
20100193508
Embodiments are generally related to microwave devices. Embodiments are also related to interlock switch module for use with microwave devices.
Microwave devices generally include a microwave energy-generating source such as, for example, a magnetron for delivering energy into a cavity defined by a cabinet having a front opening selectively enclosed by a door. Such microwave devices can be utilized as an energy source for cooking food. The magnetron generates microwaves at a particular frequency to interact with molecules in the food, thereby heating the food directly. In such microwave devices, if the cabinet door does not completely close, microwave radiation may leak from the device through a narrow air gap located around the periphery of the door to the microwave device. Leakage of such microwave radiation can adversely affect nearby electronic devices (e.g., a television receiver) and may also be harmful to individuals located near the microwave device. Radiation of such energy beyond the enclosure in certain instances may constitute harmful exposure. Thus, safety standards have been established by regulatory agencies governing the use of such microwave devices.
To prevent the leakage of microwave energy from the cavity during operation of a microwave oven, it is important to positively prevent access to the device cavity when the microwave energy generating means is energized. Thus, an interlocking component for assuring that the cabinet door is in a closed and latched position before the microwave energy generating means is energized is typically utilized in conventional microwave devices.
A number of different interlocking switch assemblies have been developed to provide such functionality. Additionally, such switch assemblies for use with microwave device doors can prevent serious damage to expensive equipment associated with the microwave device, including for example, high voltage supplies. Such switch assemblies are often utilized with particular electrical circuitry to substantially reduce hazards associated with the high voltage supplies. The majority of prior art switch assemblies for microwave device doors that continually carry currents of substantial magnitude may fail in a closed position and thereby render such switch assemblies completely ineffectual as a safety device.
Based on the foregoing, it is believed that a need exists for an improved microwave door interlock switch system capable of preventing the escape and leakage of microwave radiation, as described in greater detail herein.
The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed and is not intended to be a full description. A full appreciation of the various aspects of the embodiments can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
It is, therefore, one aspect of the present invention to provide for an improved interlock switch system for use with a heating appliance in order to assure proper door locking for the confinement of generated heating energy while the heating appliance is energized.
It is another aspect of the present invention to provide for an improved adjustment mechanism capable of setting a switch point precisely when a microwave door is closed.
It is a further aspect of the present invention to provide for a method of manufacturing and/or configuring such a switch system.
The aforementioned aspects and other objectives and advantages can now be achieved as described herein. A microwave door interlock switch system and method of making the same is disclosed, which includes a primary switch and a monitor switch that are actuated in sequence via an actuating lever (e.g., plastic). The primary switch is generally associated with a primary control circuit that controls the operation of a magnetron associated with a microwave device. The monitor switch can function as a monitor to verify the correct state of the primary switch. The interlock switch system further includes a mounting bracket, a base mounting bracket, a compression spring and an adjustment screw. The compression spring adjustment mechanism allows an assembler of the microwave device to fine-tune the location of the interlock switch system during assembly of the microwave device. The switch actuation can be set to occur at a precise point of door closure.
The shape of the actuating lever and the position of the switches ensure that each switch is always operated in a proper sequence. The interlock switch system can be mounted to the side of the microwave door and mounted with screws, when opened, can provide access to the cooking chamber. The contact with the interlock switch system is broken and the interlock switch system deactivates when the door is removed or opened. When the door is closed and contact resumed, the switch system is reactivated. The adjustment mechanism can be utilized to set the switch point precisely when the door is closed, thereby providing an improved door interlock switch system in complying with national and international safety standards while preventing the escape of stray radiation from the microwave device.
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the embodiments disclosed herein.
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
The primary switch 150 is associated with a primary control circuit, such as that depicted in
The primary switch 150 and the monitor switch 140 can be actuated in sequence via the actuating lever 120. Note that the actuating lever 120 may be configured from a material such as, for example, plastic, or another suitable material. The actuating lever 120 can further interface with a door of the microwave device 300, and when opened, provide access to the cooking chamber of the device 300. The contact with the interlock switch system 100 can be broken and the interlock switch system 100 deactivated when the door cover is removed or opened. When the door is closed and contact resumed, the switch system 100 is reactivated.
The compression spring adjustment mechanism 190 accomplished via the adjustment screw 160 and the compression spring 170 can be utilized to set the switch point precisely when the door is closed. The compression spring adjustment mechanism 190 can be utilized to adjust the position of the subassembly 125 comprising the actuating lever 120, the main mounting bracket 130, the primary switch 150 and the monitor switch 140. The compression spring adjustment mechanism 190 maintains the position of the primary switch 150 and the monitor switch 140 relative to the actuating lever 120 after adjustment in order to actuate each switch 140 and 150 in a proper sequence.
Note that the embodiments discussed herein should not be construed in any limited sense. It can be appreciated, however, that such embodiments can be implemented in the context of other devices and designs, and are not limited to the microwave device and may be subject to change by skilled persons within the scope of the invention without departing from the concept thereof.
The independent safety switches 140 and 150 can interrupt power to the magnetron 240 by two separate mechanical means when the microwave device door is opened. In the preferred embodiment, the primary switch 150 associated with appropriate electrical control means such as shown in
The primary switch 150 associated with the primary control circuit 200 of
The current line 250 can be provided with a fuse 220 that prevents an over current from being supplied to the magnetron 240 if the primary switch 150 fails. The monitor switch 140 and the primary switch 150 of the door switch assembly 100 can be connected in series to the power supply part 210 within the commercial current line 250. On the closed loop, the primary switch 150 can be connected and closed when the door of the microwave device 300 is closed. Also, the monitor switch 140 can be operated in reverse relative to the operation of the primary switch 150. With this configuration, while the door of the microwave device 300 is closed, the primary switch 150 can be maintained in a closed state.
A secondary switch 230 can be in a closed state if external closing signals are provided (i.e., when the primary switch 150 is closed). At this instance, the monitor switch 140 can be in an open state, thereby permitting the electric power from the power supply part 210 to be supplied to the magnetron 240. The electromagnetic waves generated by the magnetron 240 based on the supplied electric power can be supplied into the chamber of the microwave device 300. When the door of the microwave device 300 is opened, however, the primary switch 150 is maintained in an open state. Thus, irrespective of whether the secondary switch 230 is opened or closed, the electric power to be supplied to the magnetron 240 can be terminated. Consequently, the number of necessary switches may be decreased and the circuit structure 200 simplified. With such a configuration, the cost of production can be lowered and the stability of circuit 200 improved.
Note that there are many different types of microwave devices, which can be utilized to implement microwave device 300. For example, one type of microwave device that may be modified for use as microwave device 300 is disclosed in U.S. Pat. No. 7,091,458, entitled “Door Assembly for Microwave Oven,” which issued to Lee et al on Aug. 15, 2006. U.S. Pat. No. 7,091,458 is incorporated herein by reference. Another type of microwave device, which may be modified for use as microwave device 300, is disclosed in U.S. Patent Application Publication No. US20050194380 entitled “Microwave Oven,” which published on Sep. 8, 2005 and was invented by inventors Ho Kim et al. U.S. Patent Application Publication No. US20050194380 is also incorporated herein by reference. A further example of a microwave device that may be modified for use as microwave device 300 is disclosed in U.S. Pat. No. 7,053,348, entitled “Microwave Oven,” which issued to Tereda et al on May 30, 2006. U.S. Pat. No. 7,053,348 is incorporated herein by reference. It is understood that such microwave devices represent merely non-limiting examples of some types of devices that may be modified for use with alternative embodiments.
It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
