Abstract:
A temperature sensing system for a cooking appliance having an upper housing having a first heating surface and a lower housing having a second heating surface includes a temperature sensing probe, a control panel and a control unit in electrical communication with the temperature sensing probe and the control panel. The temperature sensing probe is removably received by the upper housing and extends through said first heating surface. The control panel has one or more input buttons for allowing a user to select at least one input parameter including a desired internal temperature of a food item.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to cooking appliances and, more particularly, to an temperature sensing system for a cooking appliance. 
       BACKGROUND OF THE INVENTION 
       [0002]    Cooking appliances, and in particular electric cooking/grilling devices such as griddles, are known. These grilling devices typically have a lower housing having a lower cooking surface and an upper housing having an upper cooking surface, wherein the cooking surfaces are typically heated by an electrical resistance heater. A handle attached to the upper housing allows a user to raise and lower the upper housing relative to the lower housing to accommodate a food item therebetween to be heated. 
         [0003]    While existing grilling devices are generally suitable for what is regarded as ordinary performance, there is room for improvement in terms of convenience, ease of use and increased functionality. As will be readily appreciated, to determine the temperature or doneness of food items, typical grills require a user to open the grill and pause cooking in order to insert a thermometer. In view the tedious nature of this process, there is a need for a cooking appliance that includes a means for measuring the doneness of food items during cooking. 
       SUMMARY OF THE INVENTION 
       [0004]    It is an object of the present invention to provide a cooking appliance having a temperature sensing system. 
         [0005]    It is another object of the present invention to provide a temperature sensing system for a cooking appliance for detecting the internal temperature of a food item during cooking. 
         [0006]    These and other objects are achieved by the present invention. 
         [0007]    According to an embodiment of the present invention, a temperature sensing system for a cooking appliance having an upper housing having a first heating surface and a lower housing having a second heating surface includes a temperature sensing probe, a control panel and a control unit in electrical communication with the temperature sensing probe and the control panel. The temperature sensing probe is removably received by the upper housing and extends through said first heating surface. The control panel has one or more input buttons for allowing a user to select at least one input parameter including a desired internal temperature of a food item. 
         [0008]    According to another embodiment of the present invention a cooking appliance is provided. The cooking appliance includes an upper housing having an upper heating surface and a lower housing having a lower heating surface, a temperature sensing probe received by the upper housing and extending through the upper heating surface, a control panel having one or more input buttons for allowing a user to select at least one input parameter, and a control unit in electrical communication with the temperature sensing probe and the control panel. The at least one input parameter includes a desired internal temperature or doneness of a food item. 
         [0009]    According to yet another embodiment of the present invention, a method of operating a cooking appliance having an upper heating surface and a lower heating surface is provided. The method includes the steps of equipping the cooking appliance with a control unit and a temperature sensing probe, and operating the upper heating surface and the lower heating surface in dependence upon data from the temperature sensing probe. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below: 
           [0011]      FIG. 1  is a perspective view of a cooking appliance having a temperature sensing probe according to another embodiment of the present invention. 
           [0012]      FIG. 2  is another perspective view of the cooking appliance of  FIG. 1 . 
           [0013]      FIG. 3  is a side-cross sectional view of the cooking appliance of  FIG. 1 . 
           [0014]      FIGS. 4-7  are various view of the temperature sensing probe of the cooking appliance of  FIG. 1 . 
           [0015]      FIG. 8  is an exploded view of the temperature sensing probe of the cooking appliance of  FIG. 1 . 
           [0016]      FIGS. 9-15  are various views illustrating operation of the temperature sensing probe of the cooking appliance of  FIG. 1 . 
           [0017]      FIG. 16  is a perspective view of a temperature sensing probe locking mechanism of the cooking appliance of  FIG. 1 . 
           [0018]      FIG. 17  is an exploded view of the temperature sensing probe locking mechanism of  FIG. 16 . 
           [0019]      FIG. 18  is a bottom plan view of the locking mechanism of  FIG. 16  in a locked position. 
           [0020]      FIG. 19  is a bottom plan view of the locking mechanism of  FIG. 16  in an unlocked position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Referring to  FIGS. 1 and 2 , a cooking appliance  10  according to an embodiment of the present invention is shown. As shown therein, the cooking appliance  10  generally takes the form of a countertop grill and includes a lower housing  12  having a lower heating/cooking plate  14  and an upper housing  16  having an upper heating/cooking plate  18 . The upper housing  16  is operatively connected to the lower housing  12  via opposed frame members  20  extending from the lower housing  16 . In particular, as shown therein, the upper housing  16  rides in a guide track  22  in the frame members  20 . A handle  24  attached to the upper housing  16  allows a user to raise and lower the upper housing  16  in the guide track  22  in order to selectively position the upper housing  16  in various positions in relation to the lower housing  12 . 
         [0022]    As best shown in  FIGS. 1-3 , the cooking appliance  10  also includes a temperature sensing probe  26  that is configured to extend through the upper housing  16  and upper heating plate  18  to selectively penetrate and pierce a food item  28  positioned between the upper and lower heating plates  14 ,  18 . In particular, the temperature sensing probe  26  can be inserted into an aperture  48  formed in the upper housing  16  and upper heating plate  18  in order to pierce a food item  28 . The probe  26  may also be locked in place, once inserted, by a lock button  50 , as discussed in detail below. 
         [0023]    As shown in  FIGS. 4-8 , the temperature sensing probe  26  includes a probe housing  30  having a piercing shaft  32 , a rotatable knob  34  that is substantially cylindrical in shape, and a guide cylinder  36 . A temperature sensor  38  is housed within a distal tip of the shaft  32  for sensing the internal temperature of food items. A conductive wire  44  connects the temperature sensor  38  to a pair of terminals  46  in the housing  30 . 
         [0024]    As also shown in  FIGS. 4-8 , the probe housing  30  is operatively connected to the guide cylinder  36  via protrusions  40  on the probe housing  30  that are received in angled slots  42  formed in the guide cylinder  36 . The guide cylinder  36 , in turn, is housed within the rotatable knob  34 . The protrusions  40  on the probe housing  30  are also received in substantially vertical grooves  47  formed in the interior of the rotatable knob  34 , as best shown in  FIG. 8 . Importantly, this engagement of the protrusions  40  with knob  34  serves to translate rotation of the knob  34  into corresponding rotation of the probe housing  30 . 
         [0025]    In operation, as the knob  34  is rotated, the probe housing  30  also rotates therewith, due to the engagement of the protrusions  40  on the probe housing with the vertical grooves  47  formed in the knob  34 . More specifically, as the knob  34  rotates, the protrusions  40  slide up or down within the vertical groove  47  of the knob  34 , and within the angled slots  42  of the guide cylinder  36 . This arrangement allows for the selective extension or retraction (depending on the direction of rotation of the knob  34 ) of the probe housing  30 , and thus the piercing shaft  32 .  FIGS. 4 and 5  illustrate the piercing shaft  32  in a retracted position, while  FIGS. 6 and 7  illustrate the piercing shaft  34  in an extended position. In this manner, a user can control the piercing depth of the probe  26  in order to orient the temperature sensor  38  most closely to the middle of the food item  28  being heated. 
         [0026]    With reference to  FIG. 9 , when the temperature sensing probe  26  is positioned in the upper housing  16 , a temperature signal is transmitted from the temperature sensor  38  to the printed circuit board (PCB) of a control unit (not shown) housed within the cooking appliance  10 . In particular, the temperature sensor  38  is electrically connected to the two terminals  46  via wire  44 . These terminals  46  are themselves in contact with a slim conductive strip  52  of the guide cylinder  36 . As also shown therein, the slim conductive strip  52  is in contact with a conductive plate  54  of the upper housing  16 , which is in contact with terminals  56  in the housing  16 . These terminals  56  are electrically coupled to the PCB by conductive wire  58 . By way of this conductive pathway, the temperature of a food item is detected by the temperature sensor  38  and is transmitted to the control unit of the cooking appliance  10 . 
         [0027]    As further shown in  FIG. 9 , a resilient seal  59  is positioned in the upper housing  16  and surrounds the aperture  48 . The seal  59  prevents grease and food from entering the upper housing  106 , thereby providing for a degree of cleanliness. 
         [0028]    As alluded to above, the cooking appliance  10  also includes a locking mechanism  60  for selectively locking the temperature sensing probe  26  in place. As shown in  FIGS. 16 and 17 , the locking mechanism  60  includes the lock button  50 , a substantially U-shaped actuating member  62  connected to the lock button  50 , and a pair of sliders  64  each having a spring  66 . 
         [0029]      FIGS. 10 and 11  illustrate the temperature probe  26  in a locked position. As shown, the probe  26  is locked in place by the sliders  64 . Importantly, as the sliders  64  are spring-biased by springs  66  towards the temperature probe  26 , the probe  26  is automatically locked into place when the probe  26  is inserted into the upper housing  16 . 
         [0030]      FIGS. 12-15 , conversely, illustrate unlocking and removal of the temperature sensing probe  26  from the upper housing. As shown therein, movement of the lock button  50  causes the sliders  64  to move against the bias of springs  66  and away from the temperature sensing probe  26 . In this position, the temperature sensing probe  26  may be removed from the housing  16 , as the sliders  64  are no longer engaged with a retaining plate  68  of the probe  26 . 
         [0031]      FIGS. 18 and 19  are bottom views of the upper housing  16  illustrating the locking mechanism  60  in a locked position and unlocked position, respectively. 
         [0032]    In the preferred embodiment, the cooking appliance  10  includes a control system that allows a user to precisely control the degree of doneness or temperature of food items. In particular, the control system includes the temperature sensing probe  26  and the control unit, as described above, as well as a control panel  70  on the face of the cooking appliance  10 . The control panel  70  includes an array of buttons that allow a user to select and set a variety of cooking or heating parameters. For example, a user can select a desired internal temperature of the food item to be cooked, or a desired degree of doneness. The control unit is configured to control operation of the one or both of the heating plates  14 ,  18  in dependence upon the preset cooking or heating parameters, and in dependence upon the temperature of a food item detected by the temperature sensing probe  26 . 
         [0033]    In particular, in operation, a user can select a desired degree of doneness (e.g., rare, medium, well done) utilizing the control panel  70  on the lower housing  12 . Throughout the cooking or heating process, the temperature sensing probe  26  continuously or intermittently monitors the internal temperature of the food item and sends a signal to the control unit that is indicative of the detected temperature. When the temperature sensing probe  26  detects the pre-set temperature, or a temperature corresponding to the desired degree of doneness as set by a user, the control unit automatically turns off the heating plates  14 ,  18  to prevent overcooking. In addition, after the desired temperature is reached, the control unit is configured to generate an audible alert, such as a beep, to indicate to a user that the food item is cooked to the desired doneness. 
         [0034]    As will be readily appreciated, the cooking appliance  10  of the present invention therefore provides a level of control over the cooking or heating operations that has heretofore not been possible with existing devices. In particular, the configuration of existing cooking appliances typically requires that a user manually insert a meat thermometer into a food item and manually monitor the temperature of the food item. By automatically monitoring the internal temperature of the food throughout cooking, without having to open the appliance  10  or pause cooking, and by controlling operation of the cooking appliance  10  in dependence upon pre-set and detected temperatures, more precise cooking, and therefore better tasting food, is realized. 
         [0035]    In addition, the cooking appliance  10  of the present invention provides a greater level of convenience by automatically monitoring the internal temperature of a food item without requiring constant attention by a user. Moreover, the ability to remove the temperature sensing probe  26  from the cooking appliance  10  allows for more convenient use and makes the probe  26  easier to clean. 
         [0036]    Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of this disclosure.