Patent Publication Number: US-2016227609-A1

Title: Multi function glass or glass-ceramic cooktop system and method of cooking thereon

Description:
BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure is related to a glass or glass-ceramic cooktop system and a use thereof in methods for performing multiple food cooking operations. More particularly, the present disclosure is related to a glass or glass-ceramic cooktop system having a glass or glass-ceramic cooktop with one or more cooking zones and two or more limiters or limiter settings for adapting to varying time-temperature load requirements between a standard cooking operation and a non-standard cooking operation. 
     2. Description of Related Art 
     Cooktops in residential settings are generally used for standard cooking operations. As used herein, a “standard cooking operation” refers to the use of a cooktop for cooking in pot sizes that are typically found in residential kitchens, cooking food volumes that are typically prepared in residential kitchens, and cooking at parameters (e.g., temperature, time) that are typically used in residential kitchens. 
     However, many cooktops are also used for a non-standard cooking operation. As used herein, a “non-standard cooking operation” refers to the use of a cooktop for cooking in larger pot sizes, larger food volumes, and higher cooking parameters than are typically used in residential kitchens. One such “non-standard cooking operation” is canning. Canning has larger requirements, especially with respect to time and temperature load requirements, than standard cooking operations. 
     More specifically, canning is a process used to preserve food in a sealed and airtight container. Canning increases shelf life and prevents food from spoiling. During a canning operation, food is preserved by first heating the food, and then by excluding air. Foods that are being canned are typically placed in canning jars and sealed with a lid that includes a rubber gasket or an o-ring. For canning operations, canning jars are usually heated in a water bath or in a sealed pressure canning pot to a canning temperature that is specific to the type of food being canned and are then maintained at the canning temperature for a certain period of time for sterilization. 
     Canning operations can take a very long time compared to standard cooking operations. One reason for this is that large diameter and tall pots must be used to accommodate the large amounts of cooked material, including the pot, water, jars, and food. Unfortunately, many commercially available cooktops are not suitable for use with non-standard cooking operations such as those present in canning. 
     Accordingly, it has been determined by the present disclosure that there is a need for cooktops that can effectively handle both standard and non-standard cooking operations. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     The present disclosure provides a glass or glass-ceramic cooktop system having a glass or glass-ceramic cooktop with a cooking zone and a cooking-zone regulator so that both non-standard cooking operations and standard cooking operations can interchangeably occur. 
     The present disclosure provides such a glass or glass-ceramic cooktop having one or more adapted cooking zones in which both non-standard and standard cooking operations can interchangeably occur without limiting the cooking time for the standard cooking operation. 
     The present disclosure also provides such a glass or glass-ceramic cooktop system that provides protection against overheating for both the non-standard and standard cooking operations. 
     The present disclosure further provides such a glass or glass-ceramic cooktop system in which the glass or glass-ceramic cooktop has an adapted heating area, and the system has a heating element that is thermally connected to the heating area, with the heating element also having a limiter system that adjusts for or implements a standard cooking operation and a non-standard cooking operation. 
     The present disclosure still further provides that the limiter system has a first limit suitable for a standard cooking operation and a second limit, different from the first limit, suitable for a non-standard cooking operation. 
     The present disclosure still further provides that the limiter system is a two-step limiter with a first step suitable for a standard cooking operation and a second step, different from the first step, suitable for a non-standard cooking operation. 
     The present disclosure yet further provides such a glass or glass-ceramic cooktop system that has a selector switch, which enable the user to select the desired cooking operation, or that has a sensor which automatically selects the needed operation by detecting the pot diameter. 
     A cooktop system has a glass or glass-ceramic cooktop, a control panel, a control system, and at least one heating zone. The control system, the control panel, and the at least one heating zone are operatively connected. Further, the control system has a first temperature limiter setting that is suitable for a standard cooking operation and a second temperature limiter setting that is suitable for a non-standard cooking operation. The second temperature limiter setting is different from the first temperature limiter setting. 
     The above-described and other features and advantages of the present disclosure will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  shows a glass or glass-ceramic cooktop of the cooktop system of the present disclosure with a touch sensor control panel according to an embodiment of the present disclosure. 
         FIG. 2  is a schematic of a control panel circuit for the glass or glass-ceramic cooktop of  FIG. 1 . 
         FIG. 3  is a top view of a dual ribbon heater with a two temperature limiter for the glass or glass-ceramic cooktop of  FIG. 1 . 
         FIG. 4  is a cross sectional view taken along lines  4 - 4  of the dual ribbon heater of  FIG. 1 . 
         FIG. 5  is a flow diagram of a cooking operation performed on the glass or glass-ceramic cooktop of  FIG. 1 . 
         FIG. 6  is a schematic of a second control circuit for the glass or glass-ceramic cooktop system of the present disclosure. 
         FIG. 7  shows a glass or glass-ceramic cooktop with selector elements according to a second cooktop embodiment of the present disclosure. 
         FIG. 8  shows a glass or glass-ceramic cooktop with touch sensors according to a third cooktop embodiment of the present disclosure. 
         FIG. 9  shows a glass or glass-ceramic cooktop having cooking zones or cooking areas according to a fourth cooktop embodiment of the present disclosure. 
         FIG. 10  shows the glass or glass-ceramic cooktop and control panel according to the present disclosure incorporated into a stove or oven with the control unit in the front. 
         FIG. 11  shows the glass or glass-ceramic cooktop and control panel according to the present disclosure incorporated into a stove or oven with the control unit in the back. 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Referring to the drawings and in particular to  FIG. 1 , there is shown a glass or glass-ceramic cooktop system having a glass or glass-ceramic cooktop according to the present disclosure generally referenced by numeral  100 . Cooktop  100  has a control panel  110 , multiple cooking zones  120  and selector switch  130 . In the embodiment shown in  FIG. 1 , cooking zones  120  are four discrete cooking zones, namely zone  122 , zone  124 , zone  126 , and zone  128 . As shown in the embodiment of  FIG. 1 , each cooking zone of cooktop  100  is a different size. Size, as used in the present disclosure, means the area receiving heat from a heating element and within which heat is transferred to any article placed thereon. In other embodiments of the present disclosure, cooking zones  120  can be the same size, or combinations of the same and different sizes. Although illustrated as four zones, there can be any number of zones including just one zone  120  and, if more than one zone, any combination of sizes feasible in the surface area of the cooktop  100 . Also, cooking zones  120  on a cooktop  100  can have different configurations, although the same configuration, such as circular, is preferred. 
     In an exemplary embodiment, at least one cooking zone, such as, for example, cooking zone  122  can be a combination cooking zone in which a standard cooking operation or a non-standard cooking operation, such as canning, can be carried out. For such a cooking zone  122 , the user will need to specify which of the two operations is to be used prior to commencement of the cooking process. This selection will be discussed in detail with respect to  FIG. 5 . 
     Each cooking zone  120  is heated by a radiant heating element  225  shown in  FIG. 2 . The radiant heating element(s)  225  are situated beneath cooktop  100 . Preferably, one heating element  225  is located under each cooking zone  122 ,  124 ,  126 , and  128 , and all heating elements  225  are thermally connected to cooktop  120 . 
     Control panel  110  is, in the embodiment of  FIG. 1 , a touch sensor control panel. Control panel  110  has controls  112 ,  114 ,  116  and  118  for energizing and de-energizing, i.e., turning on and off, and for selecting the power level of the selected cooking zones and corresponding radiant heating elements. As shown in  FIG. 1 , cooking zones  122 ,  124 ,  126  and  128  are energized or deenergized by power controls  112 ,  1114 ,  116  and  118 , respectively. As an example, the control for the power level for cooking zone  128  can be on a scale of 1 to 10, low to medium to high, or some other power differentiating scale setting, by actuating power control  118 . Control panel  110  has an on/off or power switch  130  for turning on and off cooktop  100 . Controls  112 ,  114 ,  116 , and  118  can be used for selecting which type of cooking operation is to be undertaken, such as a standard operation or a non-standard cooking operation. Alternatively, it is envisioned that an additional switch or series of switches in control panel  110  can be used for selecting which type of cooking operation is to be undertaken. The non-standard cooking operation is, for example, a canning operation that normally has the time and temperature concerns noted above. Selector switch  112  is operatively connected to the radiant heating elements via relay switch  220 , and can vary the time-temperature load requirements for different cooking operations. 
     Cooktop  100  is operated, as shown in  FIG. 2 , by a control circuit  200  of heating element  225  of the present disclosure. To facilitate the explanation of the cooktop system, control panel  110  is reproduced in  FIG. 2  along with control circuit  200  of heating element  225 . Control circuit  200  includes a relay switch  220  connected to control panel  110 , and a limiter system. As shown in  FIG. 2 , the limiter system has a first limiter  230  connected to one pole or contact setting  223  of relay switch  220  and a second limiter  240  connected to a second pole or contact setting  224  of relay switch  220 . However, the present disclosure provides, in another embodiment, that the limiter system can be a two-step limiter. Selector switch  112  of control panel  110  is used by the user to select the cooking operations. Relay switch  220  controls which of contact setting  223  and contact setting  224  is engaged. First limiter  230  and second limiter  240  are each selectable for limiting a temperature and power load of heating element  225 . Further, first limiter  230  and second limiter  240 , along with a junction  232 , complete the circuit  234 . Control circuit  200  is electrically connected to a power source, such as line power  250 . In the embodiment shown, control circuit  200  is analog. However, control circuit  200  can be digital. 
     Contact setting  223  enables first limiter  230 . First limiter  230  is set for non-standard cooking operation, such as canning. Setting  224  enables second limiter  240  that is set for standard cooking operations. First limiter  230  and second limiter  240  control heating element  225 , which heats the cooking surface of cooktop  100 . Heating element  225  is preferably a radiant heating element. First limiter  230  and second limiter  240  can be electromechanical limiters, such as, for example, thermocouplers or resistance elements. 
     Relay switch  220  is activated by selector switch  112  to switch between different electric circuits or different portions of an electric circuit and thus activate first limiter  230  or second limiter  240 . Due to relay switch  220 , first limiter  230  and second limiter  240  cannot be activated at the same time. This is important to protect against thermal overload. Relay switch  220  can be a remote-controlled switch and thus remotely control by selector switch  112 . More preferably, relay switch  220  can be an electromechanical relay, a semiconductor relay, a mechanical limit selector switch, an electronic limit selector switch, or an electromechanical selector switch. 
     Referring to  FIG. 3 , first limiter  230  is operatively connected to a rod  235  beneath a glass or glass-ceramic plate  410 . Likewise, second limiter  240  is operatively connected to a rod  245  beneath glass or glass-ceramic plate  410 . 
     An inner heating circuit  420  and an outer heating circuit  415  for delivering electricity to the heating element are also shown. Heating ribbon  425  and heating ribbon  430 , which comprise heating element  225 , generate heat when electricity flows therethrough. Heating ribbon  425  and heating ribbon  430  are electrically connected to inner circuit  415  and outer circuit  420 , respectively. An insulating material  450  is positioned under to protect any structure beneath cooktop  100  from heat damage. 
     Referring to  FIG. 5 , a cooking operation  500  of the glass or glass-ceramic cooktop system according to the present disclosure is illustrated. At step  510 , switch  130  on control panel  110  switches on cooktop  100 . At step  520 , a cooking zone  120  is selected. Cooking zone  120  can be either a standard cooking zone, such as cooking zone  126 , or a combination cooking zone, such as cooking zone  122 . If a combination cooking zone  122  is selected, the appropriate setting, control  112  on control panel  110 , is also selected. 
     If a combination cooking zone, such as cooking zone  122 , is selected, then a type of cooking process must be selected at step  530 , namely a standard cooking operation  540  or a non-standard cooking operation  550 , such as canning. 
     If a standard cooking operation is selected at step  540 , then a standard or single heating element  225  and first limiter  230  and standard thermal limiter setting is selected at  545 . The standard thermal limiter setting is higher than the non-standard thermal limiter setting since the canning load, for example, is not taken into consideration. 
     If instead, a non-standard cooking operation, such as canning, is selected at step  550 , then all heating circuits of heating element  225 , i.e., all zones, will be actuated and a canning thermal limiter setting will be selected. The canning thermal limiter setting is lower than the standard thermal limiter setting. 
     Once the limiter setting is set, then there is a selection of the power level at step  560 . Thereafter, at step  570 , the food products are prepared and cooked on the cooktop. The process ends at step  580  with the cooktop system being switched off. 
     The limiter setting, which is defined by way of the temperature of the top surface of the glass or glass-ceramics, determines the cooking time, which is important for the user. The higher the temperature on the top surface of the glass or glass-ceramics, the shorter the cooking time. However, the temperature of the top surface of the glass or glass-ceramics is limited, in turn, by the temperature resistance of the glass or glass-ceramics used. In practical use, different cooking characteristics and different pot qualities lead to greatly different temperature loads on the cooking surface over different load times. 
     These temperature-time loads may not exceed the temperature-time load capacity limits of the respectively used glass or glass-ceramics, because, otherwise, thermal overload of the glass or glass-ceramics and hence the destruction of the cooking surface results. 
     In cooktop  100  of the present disclosure, electronic temperature regulation or several temperature switching points, can be implemented through the temperature sensor. 
     While described herein as two limiter settings, there can be three, four, or more limiter settings. Also, a limiter setting can be set to a predetermined threshold. 
     Heating element  225  can be designed as single-coil heating element or a multiple-zone heating element with heating diameters corresponding to its cooking zone  120 . As stated above, each heating element  225  is equipped with two electromechanical limiters, or a two-step limiter with a switching contact, and/or at least one electronic temperature limiter or a thermocouple or a resistance element. The limiter allows implementation of the differing heating element settings as are required for the different cooking operations, i.e., standard and non-standard. 
     Heating elements  225  can be tubular heating elements, solid heating plates, and any heating systems covered with a glass or glass-ceramic. Heating elements  225  are preferably radiant heating elements, composed essentially of heating ribbon introduced onto thermal insulation. An insulation ring serves as edge insulation and, at the same time, as a spacer between the heating ribbon and the glass or glass-ceramics of cooktop  100 . For example, when a voltage is applied, the heating ribbon is heated to approximately 1050° C. and emits the heat as IR radiation. 
     To protect the glass or glass-ceramics of cooktop  100  from overheating, an electromechanical thermal cutoff (TCO) can be installed between the heating ribbon and the glass or glass-ceramics of cooktop  100 . Cutoffs are known in the art. The cutoff is composed of a rod and a head. The rod comprises two materials with different thermal expansions, which undergo different expansion in length relative to each other when they are heated. This different expansion in length serves as a trigger for a switching contact in the head. The switching temperature of the cutoff can be adjusted by way of variable spacing of the rod. Cut-offs can also have a two-step switching contact. In a two-step system, it is possible to adjust two different switching temperatures. 
     In addition to the electromechanical temperature cutoffs described, the cut-off can also use a thermocouple such as a type K. A type K thermocouple for example is made of nickel alloy having chrome, aluminum, manganese, and silicon. A type K thermocouple has a sensitivity of approximately 41 pV/° C., useful for temperature ranges such as −200 through −1350° C. (−330 through 2460° F.). Further, there are Type J thermocouples, Type N thermocouples, Type R thermocouples, Type S thermocouples, Type T thermocouples, Type B thermocouples, Type E thermocouples, platinum/rhodium alloy thermocouples, Iridium/rhodium alloy thermocouples, platinum/molybdenum alloy thermocouples, gold/iron alloy thermocouples, and the like. 
     The cut-off can also be a temperature-dependent resistor, such as a PT100 or PT1000. A PT100, for example, has the sensitivity of a standard 100 ohm sensor, a nominal 0.385 ohm/° C., but can have sensitivity between about 0.375 and 0.392 ohm/° C. Further, the use of electrically conductive print on the backside of the glass or glass-ceramic cooktop to measure changes in electrical resistance of the glass or glass ceramic material itself is contemplated. Resistance is a direct function of the glass or glass-ceramic temperature. 
     The electrical resistances or thermoelectric voltages of a thermocouple change in proportion to the applied temperature and, therefore, can be used for the control of different limiter settings. To regulate the temperature, an additional electronic control receives a signal from the limiter, such as first limiter  230 , further processes the signal, and transmits a signal to switch via a relay  220  to heating element  225 . 
     Referring to  FIG. 6 , there is shown a control circuit  600  that is a digital circuit, but has the same functionality as control circuit  200 . Radiant heating element  620  is analogous to radiant heating element  225 . Radiant heating element  620  employs a sensor  630  as a limiter. Sensor  630  controls radiant heating element  620  based on a user input from control panel  110  via control  610  which regulates line power  650  and neutral line  660 . 
     A control circuit according to the present disclosure can also be a combination of analog and digital. For example, the control circuit can have some combination of analog components as found in control circuit  200 , digital components as found in control circuit  600 , and similar analog or digital components. 
       FIGS. 7 to 9  show other embodiments of cooktop  100  of the present disclosure. 
       FIG. 7  shows cooktop  100  with a control unit  710 . Control unit  710  uses mechanical selector knobs  712 ,  714 ,  716  and  718  for controlling cooktop  100  and a power button  730  for energizing cooktop  100 . Selector knobs  712 ,  714 ,  716 , and  718  can be turned to select a type of cooking operation and a desired power level. For example, a right turn can be used to set the standard cooking operation and a left turn can be used to set the non-standard cooking operation, such as canning. Alternatively, a left turn can be used to set the standard cooking operation and a right turn can be used to set the non-standard cooking operation, such as canning. Further, some combination of a portion of knobs  712 ,  714 ,  716 , and  718  can set the standard cooking operation by left turn and the non-standard cooking operation, such as canning, by right turn, while the remainder can set the standard cooking operation by right turn and non-standard cooking operation, such as canning, by left turn. In other embodiments, cooking zones  720  can be the same size, or combinations of the same and different sizes. Although illustrated as four zones, namely  722 ,  724 ,  726 , and  728 , there can be any number of zones and any combination of sizes. 
     Referring to  FIG. 8 , cooktop  100  has a control unit that is a touch display  810 . Touch display  810  presents a user with the various control settings for selecting which type of cooking operation is to be undertaken, such as a standard cooking operation or a non-standard cooking operation, for controlling the power level of the selected radiant heating elements, and for selecting which of cooking zones  822 ,  824 ,  826 , and  828  are to be energized. Touch display  810  augments or implements a control mechanism for cooktop  100  that allows control by gesture, tablet coupling, computer coupling, or smartphone coupling using wired or wireless communication media. In other embodiments, cooking zones  822 ,  824 ,  826 , and  828  can be the same size, or combinations of the same and different sizes. Although illustrated as four zones, there can be any number of zones and any combination of sizes. 
     In  FIG. 9 , cooktop  100  has a control unit  910  and a cooking surface  920 . Cooking surface  920  has several discrete cooking zones, but they are unmarked on cooking surface  920 . The cooking zones can be any shape, size, or combination thereof. Although shown with control unit  910 , any of control units  110 ,  710 ,  810 , or the like can be used. 
     Referring to  FIGS. 10 and 11 , there are shown two embodiments of cooktop  100  incorporated into a standard range, oven, or stove  1000  and  1100 , respectively. Stoves  1000  and  1100  have a control unit  1010  and  1110 , respectively. Control units  1010  and  1110  can be any of control units  110 ,  710 ,  810  or  910 , used to select the type of cooking operation, i.e., standard or non-standard, to select the desired the power levels of the heating elements, to select the cooking zones or number of cooking elements that are engaged, and/or to turn the power on and off. 
     In stove  1000 , control unit  1010  is located in front of cooktop  100 . In stove  1100 , control unit  1110  is located behind cooktop  100 . 
     The terms “first”, “second”, “third”, “upper”, “lower”, and the like can be used herein to modify various elements. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated. Also, when ranges are used herein, the ranges further include all subranges therebetween. 
     While the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment(s) disclosed as the best mode contemplated, but that the present disclosure will include all embodiments falling within the scope of the appended claims.