Patent Publication Number: US-2021185763-A1

Title: Control device for an oven

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application relates to and claims the benefit and priority to Spanish Utility Model Application No. 201932025, filed Dec. 11, 2019. 
     TECHNICAL FIELD 
     The present invention relates to control devices for household ovens. 
     BACKGROUND 
     Control and display devices for household ovens are known. EP291302A2 describes a household oven comprising heating elements, operating mode selection means, temperature selection means, a temperature sensor, and an electronic control system. The electronic control system is configured so that once the user has selected an operating mode and a temperature by means of using the operating mode and temperature selection means, the control system sends a signal for activating the required heating element. 
     SUMMARY 
     Disclosed is a control device for a household oven. The control device includes a control panel comprising at least one actuator configured for selecting at least one function of the oven and generating an electrical signal identifying the function of the oven selected, and a control unit in communication with the control panel configured for receiving the electrical signal generated by the actuator and identifying from the electrical signal the function of the oven selected by means of the actuator. The control device further comprises a rotary position switch configured for rotating and being positioned in a plurality of discrete positions, one of the discrete positions being a reference position, so that in each of the positions the rotary position switch activates at least one function of the oven and in the reference position the rotary position switch does not activate any function of the oven. The control device further comprises an electric motor configured for rotating the rotary position switch and positioning it in one of the discrete positions, the control unit being configured to actuate the electric motor until the rotary position switch is positioned in the position corresponding to the function selected by means of the actuator. 
     Household ovens having a control panel in which at least one rotary mechanical knob is used for selecting the function of the oven to be used capable of being positioned in a plurality of discrete positions are known in the state of the art. The rotary mechanical knob has a rotating shaft, directly attached to the rotating shaft of a rotary position switch such that they both rotate simultaneously. That is, in ovens of this type known in the state of the art, the knob and the rotary position switch are mechanically coupled to one another. Therefore, based on the final position in which a user positions the rotary mechanical knob, the rotary position switch will activate at least one function of the oven, the function corresponding to said position. 
     The control device for a household oven of the invention allows the rotary position switch of ovens known in the state of the art to be used with actuators that are not mechanically coupled to the rotary position switch. This makes it possible for the control panel of the oven to be able to comprise actuators of very different types for activating the functions of the oven, using the same rotary position switch. 
     These and other advantages and features will become apparent in view of the figures and the detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a rotary position switch, an electric motor and a position sensor for the rotary position switch connected to a control unit of a first embodiment of the control device. 
         FIG. 2  shows a front view of an oven with a second embodiment of the control device. 
         FIG. 3  shows an electrical diagram of a part of a third embodiment of the control device. 
     
    
    
     DETAILED DESCRIPTION 
     The control device for the household oven  1  comprises a control panel  20  comprising at least one actuator  21  configured for selecting at least one function of the oven  1  and generating an electrical signal identifying the function of the oven  1  selected. 
     The control device includes a control unit  30  in communication with the control panel  20  configured for receiving the electrical signal generated by the actuator  21  and identifying from the electrical signal the function of the oven  1  selected by means of the actuator  21 . 
     The control device includes a rotary position switch  10  configured for rotating and being positioned in a plurality of discrete positions, one of the discrete positions being a reference position. In each of the discrete positions, the rotary position switch  10  activates at least one function of the oven  1 , except in the reference position, where the rotary position switch  10  does not activate any function of the oven  1 . Rotary position switches, such as rotary cam switches, are known in the state of the art. The rotary position switch  10  of a first embodiment of the control device includes a plurality of cams  17  assembled on a common rotary shaft  18 , each of the cams being axially spaced with respect to the previous one on the common rotary shaft so that all the cams rotate in unison when the shaft rotates. Each of the cams is configured for acting on a switch  16  and closing a circuit associated with the switch  16 , thereby feeding a load  15  corresponding to a function of the oven  1 . In the present invention, each of the circuits will correspond with a function of the oven  1 , so that when the circuit is closed, the corresponding function of the oven  1  will be activated. Each load  15  corresponds with an element of the oven  1  configured for performing each of the functions of the oven  1 , such as the top heater, lower heater, grill, double grill, fan, light, pyrolysis, etc. When a user positions the actuator  21  in a position in which several functions of the oven  1  are being selected simultaneously, the rotary position switch  10  will be positioned in a position in which several cams will act simultaneously on their associated switches  16 , the switches  16  closing their associated circuits, the associated circuits being those corresponding to the functions of the oven  1  selected by means of the actuator  21 . 
     The control device includes an electric motor  11  configured to rotate the rotary position switch  10  and positioning it in one of the discrete positions, the control unit  30  being configured to actuate the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21 . The electric motor  11  and the control unit  30  are electrically connected, so that once the control unit  30  has identified the function of the oven  1  selected by means of the actuator  21 , it sends an electrical signal to the electric motor  11 , which will rotate the rotary position switch  10  until positioning it in that position in which the function of the oven  1  selected is activated. 
       FIG. 1  shows the rotary position switch  10 , the electric motor  11 , and the control unit  30  of the first embodiment of the control device. 
     Household ovens having a control panel in which at least one rotary mechanical actuator is used for selecting the function of the oven to be used, capable of being positioned in a plurality of discrete positions, are known in the state of the art. The rotary mechanical actuator has a rotating shaft which is directly attached to the rotating shaft of a rotary position switch such that they both rotate simultaneously. That is, in this type of ovens known in the state of the art, the actuator and the rotary position switch are mechanically coupled to one another. Therefore, based on the final position in which the user positions the rotary mechanical actuator, the rotary position switch will activate at least one function of the oven, the one corresponding to said position. 
     The control device for a household oven  1  of the invention allows the rotary position switch  10  of the ovens  1  known in the state of the art to be used with actuators  21  which are not mechanically coupled to the rotary position switch  10 . This makes it possible for the control panel  20  of the oven  1  to be able to comprise actuators  21  of very different types for activating the functions of the oven  1 , using the same rotary position switch  10 . It is thus possible to change the aesthetics of the oven  1  to a more modern aesthetic in which the control panel  20  and the actuators  21  are more modern, without changing the manner of activating the functions of the oven  1 , which is still mechanical, by means of using the rotary position switch  10 . 
     In the control device of the first embodiment, the control unit  30  is configured for identifying the reference position from among all the discrete positions, so that each discrete position in which the rotary position switch  10  is positioned is identified based on the number of positions that the rotary position switch  10  has been rotated by the electric motor  11  with respect to the reference position. As described above, the reference position is that position of the actuator  21  in which no function of the oven  1  is activated, and it is preferably identified in the actuator  21 . The user selects the reference position in the actuator  21  when he or she does not want any function of the oven  1  to be activated. 
     The control unit  30  is configured for identifying the reference position based on the signal received from the actuator  21 . Furthermore, the control unit  30  is configured for knowing how many positions separate each discrete position from the reference position. Therefore, starting from the reference position, the control unit  30  is configured for activating the electric motor  11  until the rotary position switch  10  is rotated to the discrete position selected. Likewise, the control unit  30  is configured for calculating how many positions separate one discrete position from another, so it is also configured for activating the electric motor  11  until the rotary position switch  10  is rotated to the discrete position selected starting from any previous discrete position when, during operation of the oven  1 , the user acts on the actuator  21  by deselecting the function of the oven  1  that was previously selected, by selecting an additional function of the oven  1 , or by changing the function of the oven  1  previously selected to another function 
     In the first embodiment of the control device, the control unit  30  comprises a memory configured for storing the discrete position in which the rotary position switch  10  is positioned at all times. Therefore, when the user selects a new discrete position by means of the actuator  21 , the control unit  30  knows which is the discrete position in which the rotary position switch  10  is positioned in the moment in which the user makes the selection, and it is configured for activating the electric motor  11  until the rotary position switch  10  is rotated to the discrete position selected. 
     In the first embodiment of the control device, the control unit  30  is configured for actuating the electric motor  11  until the rotary position switch  10  is positioned in the reference position, and then for actuating the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21  when power supply is restored after an interruption in the power supply. The control device comprises a power supply unit connected with the power supply. The control unit  30  is configured for detecting the interruption in the power supply, so that after the power supply has been interrupted, when power supply has been restored, the control unit  30  is configured for actuating the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21 , by first actuating the electric motor  11  until the rotary position switch  10  is positioned in the reference position, and then by actuating the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21 . 
     In the first embodiment, the control device comprises a position sensor  12  for the rotary position switch  10  in communication with the control unit  30 . The position sensor  12  shown in  FIG. 1  is configured for providing to the control unit  30  an initial position of the rotary position switch  10 , which is the position in which the rotary position switch  10  is located. The control unit  30  is configured for actuating the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function of the oven  1  selected by means of the actuator  21  from the initial position, i.e., taking into account that the starting initial position is the position provided by the position sensor  12 . 
     During the operation of the oven  1 , the user may act on the actuator  21  by deselecting the function of the oven  1  that was previously selected, by selecting an additional function of the oven  1  or by changing the function of the oven  1  previously selected to another function. The control unit  30  and the position sensor  12  for the rotary position switch  10  are electrically connected, so that when the control unit  30  receives from the actuator  21  a change in the functions of the oven  1  selected, the control unit  30  identifies the initial position in which the rotary position switch  10  is located based on the initial position provided by the position sensor  12 . The control unit  30  then identifies a final position, which is the position in which the rotary position switch  10  must be positioned for activating the function or functions of the oven  1  selected by means of the actuator  21  or actuators  21 , and based on that it calculates the signal to be sent to the electric motor  11  for it to rotate the rotary position switch  10  from the initial position to the final position. 
     In the first embodiment of the control device, the position sensor  12  is integrated in the rotary position switch  10 . However, in another embodiment the position sensor  12  is integrated in the electric motor  11 . 
     As is shown in  FIG. 1 , in the first embodiment the position sensor  12  is a potentiometer. However, in another embodiment the position sensor  12  is a rotary encoder. 
     In the first embodiment of the control device, the electric motor  11  is directly attached to the rotary position switch  10 . As is shown in  FIG. 1 , the shaft of the electric motor  11  and the shaft of the rotary position switch  10  are coaxially attached, so that the rotation of the shaft of the electric motor  11  causes the rotation of the shaft of the rotary position switch  10 . 
     The control panel  20  of the control device of the first embodiment is an electronic control panel  20 . The control device of the first embodiment allows the rotary position switch  10  used in the ovens  1  known in the state of the art to be used with the electronic control panel  20 . This makes it possible for the aesthetics of the oven  1  to be more modern than the aesthetics of the ovens  1  known in the state of the art, maintaining the use of the same rotary position switch  10 . 
     In the control device of the first embodiment, the function of the oven  1  is selected by pushing on the actuator  21 . 
     In the first embodiment of the control device, at least one actuator  21  is a button. 
     In another embodiment of the control device, at least one actuator  21  is a capacitive touch sensor. 
     In another additional embodiment of the control device, at least one actuator  21  is a rotary knob. 
     In a second embodiment of the control device shown in  FIG. 2 , the control panel  20  comprises a display screen and a touch screen, the actuator  21  being an area of the touch screen. 
     In the first embodiment of the control device, the control unit  30  is configured for receiving an electrical signal identifying a temperature inside a cavity of the oven  1  generated by a temperature sensor, and identifying from the electrical signal the temperature inside the cavity of the oven  1 . The temperature sensor is configured for detecting the temperature inside the cavity of the oven  1  and generating the electrical signal identifying the temperature inside the cavity of the oven  1 . When the control unit  30  receives the electrical signal generated by the temperature sensor, it is capable of identifying the temperature inside the cavity of the oven  1  from the electrical signal. 
     The rotary position switch  10  comprises a plurality of switches  16 , each switch  16  being associated with a circuit into which a load  15  corresponding to a function of the oven  1  is fed. The control device comprises at least one input relay  13  arranged in series with at least one switch  16  of the rotary position switch  10  and before the switch  16 . The control unit  30  is configured for opening the input relay  13  when the temperature inside the cavity of the oven  1  is greater than a maximum temperature and for closing the input relay  13  when the temperature inside the cavity of the oven  1  is less than a minimum temperature, the maximum temperature being equal to a target temperature selected through a temperature actuator plus a higher differential, and the minimum temperature being equal to the target temperature minus a lower differential. 
     The input relay  13  of the first embodiment of the control device works like a cycling switch, i.e., once the user has selected the temperature at which he or she wants the inside of the cavity of the oven  1  to be, the control unit  30  maintains the temperature by establishing on/off cycles of the circuit associated with the function of the oven  1  selected, by means of opening and closing the input relay  13  associated with the circuit in question. The higher differential and the lower differential define the hysteresis between the maximum temperature causing the input relay  13  to open and the minimum temperature causing the input relay  13  to close. 
     In a third embodiment of the control device shown in  FIG. 3 , the control device comprises only one input relay  13  connected in series with all the switches  16  of the rotary position switch  10 , so that when the temperature inside the cavity of the oven  1  is greater than the maximum temperature, the input relay  13  opens, such that all the circuits associated with all the functions of the oven  1  would be open. 
     In the first embodiment, the control device comprises at least one output relay  14  arranged in series with at least one switch  16  of the rotary position switch  10  and after the switch  16 , the control unit  30  being configured for opening the output relay  14  when it detects an anomalous operation of the control device. 
     The control unit  30  is configured for detecting malfunctions in the operation of the control device, so that if any of the elements of the control device were to fail, the control unit  30  opens the output relay  14 , so that the output relay  14  works like a safety switch. 
     In another embodiment of the control device, the control unit  30  is configured for actuating the electric motor  11  until the rotary position switch  10  is positioned in a position other than the position corresponding to the function selected by means of the actuator  21  when the temperature inside the cavity of the oven  1  is far from the target temperature, and for actuating again the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21  when the temperature inside the cavity of the oven  1  is close to the target temperature. Therefore, the thermal response of the oven  1  is improved. When switching on the oven  1 , for example, at which time the temperature inside the cavity of the oven  1  is far from the target temperature, and until the temperature inside the cavity of the oven  1  is close to the target temperature, if the function selected is the grill, the control unit  30  would actuate the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the double grill function until the temperature inside the cavity of the oven  1  is close to the target temperature, thereby improving the thermal response of the oven  1  given that the target temperature would be reached more quickly. Once the temperature inside the cavity of the oven  1  is close to the target temperature, the control unit  30  would again actuate the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the grill function. The control unit  30  works in this way in other situations in which the thermal response can also be improved, such as when the door of the oven  1  is opened, or when a large quantity of food is introduced in the cavity of the oven  1 , thus causing the temperature therein to drop. 
     The following clauses disclose in an unlimited way additional embodiments. 
     Clause 1: Control device for a household oven  1 , comprising
         a control panel  20  comprising
           at least one actuator  21  configured for selecting at least one function of the oven  1  and generating an electrical signal identifying the function of the oven  1  selected, and   
           a control unit  30  in communication with the control panel  20  configured for receiving the electrical signal generated by the actuator  21  and identifying from said electrical signal the function of the oven  1  selected by means of the actuator  21 , the control unit including a rotary position switch  10  configured for rotating and being positioned in a plurality of discrete positions, one of said discrete positions being a reference position, so that in each of said positions the rotary position switch  10  activates at least one function of the oven  1  and in the reference position the rotary position switch  10  does not activate any function of the oven  1 , and an electric motor  11  configured for rotating the rotary position switch  10  and positioning it in one of said discrete positions, the control unit  30  being configured for actuating the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21 .       

     Clause 2: Control device according to clause 1, wherein the control unit  30  is configured for identifying the reference position from among all the discrete positions, so that each discrete position in which the rotary position switch  10  is positioned is identified based on the number of positions the rotary position switch  10  has been rotated by the electric motor  11  with respect to the reference position. 
     Clause 3: Control device according to clause 2, wherein the control unit  30  comprises a memory configured for storing the discrete position in which the rotary position switch  10  is positioned. 
     Clause 4: Control device according to clause 2 or 3, wherein the control unit  30  is configured for actuating the electric motor  11  until the rotary position switch  10  is positioned in the reference position, and then for actuating the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21  after an interruption in the power supply. 
     Clause 5: Control device according to any of the preceding clauses, comprising a position sensor  12  for the rotary position switch  10  in communication with the control unit  30 , configured for providing to the control unit  30  an initial position of the rotary position switch  10 , which is the position in which the rotary position switch  10  is located, the control unit  30  being configured for actuating the electric motor  11  until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21  from the initial position. 
     Clause 6: Control device according to clause 5, wherein the position sensor  12  is integrated in the rotary position switch  10 . 
     Clause 7: Control device according to clause 5, wherein the position sensor  12  is integrated in the electric motor  11 . 
     Clause 8: Control device according to any of clauses 5 to 7, wherein the position sensor  12  is a potentiometer. 
     Clause 9: Control device according to any of clauses 5 to 7, wherein the position sensor  12  is a rotary encoder. 
     Clause 10: Control device according to any of the preceding clauses, wherein the electric motor  11  is directly attached to the rotary position switch  10 . 
     Clause 11: Control device according to clause  10 , wherein the electric motor  11  is coaxially attached to the rotary position switch  10 . 
     Clause 12: Control device according to any of the preceding clauses, wherein the control panel  20  is an electronic panel. 
     Clause 13: Control device according to any of the preceding clauses, wherein the function of the oven  1  is selected by pushing on the actuator  21 . 
     Clause 14: Control device according to clause  13 , wherein the actuator  21  is a button. 
     Clause 15: Control device according to clause  13 , wherein the actuator  21  is a capacitive touch sensor. 
     Clause 16: Control device according to any of clauses 1 to 12, wherein the actuator  21  is a rotary knob. 
     Clause 17: Control device according to any of clauses 1 to 13, wherein the control panel  20  comprises at least one touch screen, the actuator  21  being an area of said touch screen. 
     Clause 18: Control device according to any of the preceding clauses, wherein the control unit  30  is configured for receiving an electrical signal identifying a temperature inside a cavity of the oven  1  generated by a temperature sensor, and identifying from said electrical signal the temperature inside the cavity of the oven  1 , the rotary position switch  10  comprising a plurality of switches  16 , each switch  16  being associated with a circuit into which a load  15  corresponding to a function of the oven  1  is fed, the control device comprising at least one input relay  13  arranged in series with at least one switch  16  of the rotary position switch  10  and before said switch  16 , the control unit  30  being configured for opening the input relay  13  when the temperature inside the cavity of the oven  1  is greater than a maximum temperature and for closing the input relay  13  when the temperature inside the cavity of the oven  1  is less than a minimum temperature, the maximum temperature being equal to a target temperature selected through a temperature actuator plus a higher differential, and the minimum temperature being equal to the target temperature minus a lower differential. 
     Clause 19: Control device according to clause 18, wherein the control device comprises at least one output relay  14  arranged in series with at least one switch  16  of the rotary position switch  10  and after said switch  16 , the control unit  30  being configured for opening the output relay  14  when it detects an anomalous operation of the control device. 
     Clause 20: Control device according to clause 18 or 19, wherein the control unit  30  is configured for actuating the electric motor  11  until the rotary position switch  10  is positioned in a position other than the position corresponding to the function selected by means of the actuator  21 , and for actuating the electric motor  11  again until the rotary position switch  10  is positioned in the position corresponding to the function selected by means of the actuator  21  when the temperature inside the cavity of the oven  1  is close to the target temperature.