Patent Publication Number: US-6335518-B1

Title: Microwave oven with temperature sensor assembly

Description:
CLAIM OF PRIORITY 
     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from my application entitled MICROWAVE OVEN filed with the Korean Industrial Property Office on Oct. 26, 2000 and there duly assigned Serial No. 2000-63222. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates in general to microwave ovens, and more particularly, to a microwave oven having a sensor holder in a duct member, holding a temperature sensor. 
     2. Description of Related Art 
     The present invention will be described by applying it to a wall-mounted type of microwave oven. Generally, the wall-mounted microwave oven is installed over cookers such as a gas range, is etc., which functions as a hood to draw in smoke and smell generated in the gas range and discharge them. 
     FIG. 5 is an exploded perspective view of a conventional wall-mounted microwave oven. As shown therein, the conventional wall-mounted microwave oven is comprised of a main casing  101  having a cooking compartment  110  and a component chamber  115 , an outer casing  105  taking a shape of an inverse “U,” surrounding the main casing  101  and defining an outer appearance of the microwave oven, and a lower casing  103  coupled to the lower part of the main casing  101 . 
     On top of the outer casing  105  is formed an exhaust port  107 , and on the planar surface of the lower casing  103  are formed a pair of suction ports  106 . 
     The main casing  101  is comprised of a front plate  117  and a rear plate  118  which are coupled to the outer casing  105 , and a cavity casing  165  interposed between the front plate  117  and the rear plate  118 , taking a shape of a rectangular box and forming a cooking compartment  110  inside thereof. On top of the cavity casing  165  is provided a duct member  125  guiding flow of an air. 
     On the top face of the cavity casing  165  is provided a sensor bracket  127  for installing a temperature sensor  150  therein, sensing a temperature of the cooking compartment  110 . The temperature sensor  150  is comprised of a flange  151  provided at one end of the temperature sensor  150  for coupling with the sensor bracket  127 , and a pair of terminals provided in the other end of the temperature sensor  150 , supplying an external power to the temperature sensor  150 . 
     The sensor bracket  127  takes a shape of “⊂,” the closed side of which is fixed to the cavity casing  165  by welding, and the open side of which is separated from the top face of the cavity casing  165  with a predetermined space so that the flange  151  of the temperature sensor  150  is inserted thereinto. 
     Duct member  125  has recess  126  accommodating therein temperature sensor  105  inserted into sensor bracket  127 . An electrical lead (not shown) for power supply is connected to terminals  152  of temperature sensor  150  and is drawn out through recess  126 . 
     In the conventional microwave oven, to install the temperature sensor  150  on the top face of the cavity casing  165 , one side of the sensor bracket  127  has to be welded, and thereafter, the temperature sensor  150  has to be inserted into the other side of the sensor bracket  127  spaced therefrom, thereby making it cumbersome to prepare the installment of the temperature sensor  150  therein. Additionally, the conventional microwave oven lowers the efficiency of operational processes and increases the cost of production, due to the welding operation of the sensor bracket  127 . 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made in view of the above-described shortcomings, and it is an object of the present invention to provide a microwave oven having a sensor holder in a duct member, holding a temperature sensor. 
     This and other objects of the present invention may be achieved by a provision of a microwave oven having a cavity casing forming a cooking compartment, comprising a temperature sensor sensing a temperature of the cooking compartment; a duct member installed on the top face of the cavity casing, guiding a flow of air, having an opening toward the cavity casing at one side thereof; and a holder sensor provided on an inner wall of the duct member, holding the temperature sensor. 
     The sensor holder includes a pair of arms surrounding the outside of the temperature sensor, and a detent disposed between the pair of arms preventing the temperature sensor from being removed therefrom. 
     The temperature sensor has a flange radially extended from one end thereof, and the pressing means includes a spring disposed between the detent and the flange. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
     FIG. 1 is an exploded perspective view of a wall-mounted microwave oven according to the present invention; 
     FIG. 2 is an enlarged perspective view of a duct member and a temperature sensor of FIG. 1; 
     FIG. 3 is a view showing an assembly of the temperature sensor and the sensor holder of FIG. 2; 
     FIG. 4 is an exploded view of the temperature sensor and the sensor holder of FIG. 2 according to another embodiment of the present invention; and 
     FIG. 5 is an exploded perspective view of a conventional wall-mounted microwave oven. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1 which is an exploded perspective view of a wall-mounted microwave oven according to the present invention, the wall-mounted microwave oven is comprised of a main casing  1  forming a main body, an outer casing  5  surrounding the main casing  1 , defining an outer appearance of the microwave oven, and a lower casing  3  coupled to the lower part of the main casing  1 . 
     The outer casing  5  takes a form of inverse “U,” having an exhaust port  7  at the top face of the outer casing  5 . The lower casing  3  is of rectangular plate type, having a pair of suction ports  6 . 
     The main casing  1  is comprised of a front plate  17  and a rear plate  18  coupled to the front and the rear of the outer casing  5 , and a cavity casing  65  disposed between the front plate  17  and the rear plate  18 , functioning as a partition to partition a cooking compartment  10  and a component chamber  15 . On the top of the cavity casing  65  is installed a duct member  25  guiding a flow of air. 
     The wall-mounted microwave oven according to the present invention will be described in more detail with respect to FIGS. 1,  2  and  3 . 
     As shown in FIG. 2, duct member  25  is formed with recess  26  having an upper and a lower openings through which temperature sensor  50  is installed, and lamp accommodating part  56  in which lamp  57  is installed, to illuminate the inside of cooking compartment  10 . 
     A flange  51  extends radially from one end of temperature sensor  50 . A terminal  52  supplying electric power to the temperature sensor  50  is located at the other end of temperature sensor  50 . An electrical lead (not shown) for the power supply is connected to terminal  52  of temperature sensor  50 , and the electrical lead is drawn through recess  26 . 
     A sensor holder  30  is positioned on the inner wall of the recess  26  to allow the temperature sensor  50  to be fixed on the top face of the cavity casing  65 . 
     Sensor holder  30 , as shown in FIG. 3, includes a pair of arms  31  taking a shape of arc, being opposed to each other, and detent  37  disposed between the pair of arms  31  to prevent temperature sensor  50  from being removed therefrom. Each of the arms  31  includes intermediate section  33  surrounding an outer surface of temperature sensor  50 , and end section  35  inclined oppositely to temperature sensor  50 , so that temperature sensor  50  is smoothly inserted between free ends of arms  31 . Detent  37  takes a shape of rod which is elastically deformable, by pressing the upper of the temperature sensor  50  so that temperature sensor  50  cannot be removed therefrom. Detent  37  has protrusion  38  for preventing temperature sensor  50  from moving vertically. 
     With this configuration, temperature sensor  50  is installed in sensor holder  30  formed on the inner wall of recess  26 . Temperature sensor  50  is guided into intermediate section  33  through end section  35  of arms  31  to hold therein when temperature sensor  50  is moved horizontally relative to arms  31 . If temperature sensor  50  is held by arms  31  and protrusion  38  of detent  37  is engaged with the top of temperature sensor  50 , temperature sensor  50  is pressed downwardly so as to be closely contacted with the top face of cavity casing  65 . 
     With sensor holder  30  to allow temperature sensor  50  to be fixed in the inner wall of recess  26  located in duct member  25 , temperature sensor  50  can be closely contacted with the top face of cavity casing  65 , without performing a welding process to fix the sensor holder to the top face of cavity casing  65 , thereby decreasing the number of operations and further the cost of production. 
     Temperature sensor  50  can be installed on the top face of cavity casing  65  by coupling temperature sensor  50  to the sensor holder, and then fixing duct member  25  to the top face of cavity casing  65 . Alternatively, the temperature sensor  50  can be installed on the top face of cavity casing  65  by first fixing duct member  25  to the top face of cavity casing  65 , and then coupling temperature sensor  50  to the sensor holder through recess  26 . 
     Referring to FIG. 4, a spring  40  is disposed between the temperature sensor  50  and the sensor holder  30 , the spring  40  being a pressing means to press the temperature sensor  50 . 
     After the spring  40  is inserted so that it surrounds the outer surface of temperature sensor  50 , temperature sensor  50  is inserted horizontally relative to sensor holder  30 , and then detent  37  presses spring  40  downwardly. If detent  37  presses spring  40  downwardly, temperature sensor  50  is correctly contacted with the top face of the cavity casing. 
     In the present embodiment, it has been described that the spring  40  as a pressing means is disposed between the temperature sensor  50  and the sensor holder  30 . However, the pressing means may be comprised of any means capable of elastically pressing the temperature sensor  50  downwardly. 
     Sensor holder  30  of the present invention may be produced in a single body by an injection molding with duct member  25 . Alternatively, sensor holder  30  may be provided separately from duct member  25 , and sensor holder  30  and duct member  25  can be assembled by means of a screw or any screwed coupling, to allow sensor holder  30  to be installed in recess  26 . Shape of sensor holder  30  is of variety, depending upon the shape of temperature sensor  50 . 
     Height of sensor holder  30  is variable, differently from the installation height of detent  37 . 
     As described above, according to the present invention, a sensor holder holding the temperature sensor in the duct member is provided, thereby simplifying an operational process of the temperature sensor and decreasing the cost of production. 
     Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.