Abstract:
A compact thermoelectric safety actuator having a first body with a first cavity and a second body with a second cavity. The first and second bodies are connected so that the first and second cavities are arranged facing and open to one another. The first body has a gas outlet and the second body has a gas inlet in fluid communication with the gas outlet through the second cavity, An electromagnet of the actuator has a first end portion residing in the first cavity and a second end portion residing in the second cavity. A rotatable arm has a first end with a ferromagnetic frame adapted to engage the second portion of the electromagnet and a second end coupled to a sealing member, each of the tilting arm, ferromagnetic frame and sealing member are arranged in the second cavity. The first sealing member is configured to seat against a seating located on the first body when the arm is in a rest position, the first seating being located between the gas outlet and the second cavity.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The Present application relates to and claims the benefit and priority to PCT/EP2012/061018, filed Jun. 11, 2012 which claims the benefit and priority to Spanish Patent Application No. P201131008, filed Jun. 15, 2011. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a gas burner for a household appliance, in particular for an oven, stoves or other household appliance that are preferably supplied with natural gas or LPG. 
       BACKGROUND 
       [0003]    There are known gas burners for household appliances that include thermoelectric safety devices that close the passage of gas towards the burner in the absence of flame. Thermoelectric safety devices comprise magnetic units connected to a corresponding thermocouple, with the result that for as long as there is a flame in the burner, the corresponding flame thermocouple keeps the corresponding magnetic unit energized, and as a result, the thermoelectric device allows the passage of gas towards the burner. In the absence of flame, the thermocouple cools and is not able to maintain the delivery of power to the magnetic unit, as a result of which the magnetic unit is de-energized, closing the passage of gas towards the burner. 
         [0004]    From the moment the burner is lit until the thermocouple is able to keep the magnetic unit energized a period of time elapses, as a result of which it is necessary that the thermoelectric device comprises auxiliary means that, once the magnetic unit has been reset manually, allow the magnetic unit to be kept energized until the thermocouple is able to do so by itself. 
         [0005]    In general terms, thermoelectric safety devices are arranged removed from the burner close to the controls as described in U.S. Pat. No. 6,886,581 B2. The magnetic unit is arranged housed in a gas valve body, the magnetic unit being substantially aligned with a shaft of the valve body, with the result that the user must activate the control of the valve body coupled to the shaft so that said shaft acts on the magnetic unit, keeping it in the open or passage-of-gas position until the thermocouple, arranged close to a burner injector, is able to keep said magnetic unit energized. 
       SUMMARY OF THE DISCLOSURE 
       [0006]    According to one implementation a gas burner is provided that comprises at least one casing, at least one thermocouple, at least one injector supplied with a gas and fixed to the casing, and at least one thermoelectric safety actuator adapted to open or close the passage of gas towards the injector. The thermoelectric safety actuator is arranged fixed to the casing and comprises a body, at least one inlet gas conduit, at least one outlet gas conduit connected to the injector, at least one electromagnet housed in the inside of the body and arranged connected to the thermocouple, at least one tilting arm that is arranged fixed with a frame on one end and a sealing member on the opposite end. The arm tilts between a rest position in which the passage of gas from the inlet conduit towards the outlet conduit is closed by means of said sealing member, and an activation position, in which the electromagnet is energized and the passage of gas open, the electromagnet being energized initially by auxiliary energization means and being kept energized by said auxiliary energization means until the thermocouple is able to keep said electromagnet energized. 
         [0007]    As a result, an optimised and compact gas burner is obtained, and which comprises the thermoelectric safety actuator close to the injector and the thermocouple, thereby reducing the lengths and the number of conduits necessary. A burner with fewer load losses is also obtained. 
         [0008]    These and other advantages and characteristics will be made evident in the light of the drawings and the detailed description thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  shows a view in perspective of a burner according to one embodiment. 
           [0010]      FIG. 2  shows a sectional view of the burner shown in  FIG. 1 . 
           [0011]      FIG. 3  shows a sectional view of a safety actuator comprised in the burner shown in  FIG. 1 . 
           [0012]      FIG. 4  shows a view in perspective of a safety actuator comprised in the burner shown in  FIG. 1 . 
           [0013]      FIG. 5  shows a sectional view of a safety actuator of a burner according to a second embodiment. 
           [0014]      FIG. 6  shows a view in perspective of the safety actuator shown in  FIG. 5 . 
           [0015]      FIG. 7  shows a view in perspective of a safety actuator of a burner according to a third embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]      FIG. 1  shows a first embodiment of a gas burner  1  of a cooking appliance, preferably of an oven or a gas stove, which comprises a casing  5 , a thermocouple  4 , an injector  2  supplied with a gas and fixed to the casing  5 , and a mixing conduit  6  connected to the injector  2 , wherein the gas that arrives through the injector  2  is mixed with the air, said mixture exiting through holes  6   c  arranged along a substantially flat surface  6   b  of the mixing conduit  6 . The gas burner  1  also comprises a spark plug  3 , arranged substantially parallel to the substantially flat surface  6   b  of the mixing conduit  6 , which causes the necessary spark in the gas burner  1  to cause the ignition of the gas and air mixture, the spark plug  3  being activated by auxiliary energization means. 
         [0017]    In the embodiment shown in  FIGS. 1 and 2 , the thermocouple  4  and the spark plug  3  are arranged substantially parallel to each other, being extended on the substantially flat surface  6   b  by a certain distance. Both the thermocouple  4  and the spark plug  3  are arranged fixed to the casing  5 , in particular to respective extensions  5   a,    5   c  of the casing  5  substantially in the shape of an L. 
         [0018]    The gas burner  1  also comprises a thermoelectric safety actuator  20 , shown in detail in  FIGS. 3 and 4 , adapted to open or close the passage of gas towards the injector  2 . The thermoelectric safety actuator  20  is arranged fixed to the casing  5  and comprises an inlet gas conduit  23 , an outlet gas conduit  25 , a body  21 , 22  inside which is housed an electromagnet  36  adapted to be connected to the thermocouple  4 , a tilting arm  38  on one of the ends of which is arranged fixed a frame  37  and on the other end of which is arranged fixed a sealing member  35 , the tilting arm  38  tilting between a rest position in which the passage of gas from the inlet conduit  23  towards the outlet conduit  25  is closed by means of said sealing member  35 , and an activation position in which the electromagnet  36  is energized by the thermocouple  4  and the passage of gas is open. The electromagnet  36  is energized initially by auxiliary energization means, it being kept energized by said auxiliary energization means until the thermocouple  4  is able to keep said electromagnet  36  energized by itself. 
         [0019]    In the embodiment shown in  FIGS. 1 and 2 , the injector  2  is arranged coupled to the thermoelectric safety actuator  20 . 
         [0020]    According to one implementation the electromagnet  36  includes a core  36   a,  preferably in the shape of a U, and a single coil  36   b  wound around the core  36   a.  The frame  37  is ferromagnetic and closes against free transverse surfaces  36   c  of the core  36   a  when said electromagnet  36  is energized by the thermocouple  4 . 
         [0021]    The body  21 ,  22  of the thermoelectric safety actuator  20 , shown in detail in  FIGS. 3 and 4 , comprises a first member  22  that comprises the outlet conduit  25 , and a second member  21  that comprises the inlet conduit  23 . According to one implementation both the first member  22  and the second member  21  are substantially cylindrical, each one of them comprising a substantially flat contact surface  21   a,    22   a  on which are fixed both members  21 ,  22 . According to on implementation the inlet conduit  23  and the outlet conduit  25  are arranged substantially parallel to each other. The second member  21  comprises a groove  30  that extends along a closed contour on the contact surface  21   a,  there being housed in said groove  30  a gasket  29  that seals the closure between both contact surfaces  21   a,    22   a.  The first member  22  and the second member  21  each have ears  22   b,    21   b,  shown in  FIG. 1 , with respective holes through which the first member  22  and the second member  21  are fixed to each other by means of fixing means, said fixing means comprising in the embodiment shown in  FIGS. 1 and 4 , respective screws  32 . 
         [0022]    According to one implementation the first member  22  comprises a substantially cylindrical first housing  27 , in which is partially housed the electromagnet  36  projecting out partially in relation to the support surface  22   a,  and a seating  28  that projects out in relation to the support surface  22   a,  from one end of the outlet conduit  25 . According to one implementation the first housing  27  and the outlet conduit  25  are arranged substantially parallel to each other. The injector  2  is arranged coupled to the outlet conduit  25  of said thermoelectric safety actuator  20 . 
         [0023]    According to one implementation the first housing  27  includes a first part  27   a  with a smaller cross-section in which is housed supported one end of the core  36   a  of the electromagnet  36 . Additionally, the first member  22  comprises a second housing  26 , substantially coaxially to the first housing  27 , which extends from a base  22   c,  substantially parallel and opposite to the support surface  22   a,  the first housing  27  being connected to the outside of the first member  22 . In said second housing  26  is arranged inserted a connection terminal  31  connected to one end  36   d  of the coil  36   b  and a gasket  33  that seals said second housing  26 . The connection terminal  31  projects out in relation to the base  22   c,  it being adapted to be connected by a connection terminal  7   b  of a cable  7  to the thermocouple  4  as shown in  FIG. 1 . 
         [0024]    In addition, the second member  21  comprises a housing  24  in which is partially housed the tilting arm  38  along with the frame  37  and the sealing member  35 . The tilting arm  38  is arranged fixed to the first member  22  by fixing means. In the embodiment shown, the fixing means comprise screws  34 , shown in  FIG. 3 , although in other embodiments they may comprise another type of known fixing means. The tilting arm  38  has a fixed first part  38   a  and a second part  38   b  that is movable in relation to said first part  38   a,  there being arranged on the second part  38   b,  which is substantially flat, the frame  37  and the sealing member  35 . 
         [0025]    The tilting arm  38  also comprises elastic means arranged between the first part  38   a  and the second part  38   b,  which allows the tilting arm  38  to be returned from the activation position, in which the frame  37  is in contact with the core  36   a  of the electromagnet  36 , to the rest position in which a substantially flat surface  35   b  of the sealing member  35  closes, against the seating  28  to prevent the passage of gas towards the outlet conduit  25 . The elastic means comprise a compression spring  39 , the spring  39  being arranged coupled to the first part  38   a  by a projection  38   f  and to the second part  38   b  by the corresponding projection  38   e,  shown in  FIG. 3 . Furthermore, the second part  38   b  has tabs  38   c,  shown in  FIG. 3 , each one of which cooperates with a corresponding groove  38   d  that extends along the first part  38   a,  in a direction substantially orthogonal to the second part  38   b,  guiding the movement and the rotation of the second part  38   b  in relation to the first part  38   a.    
         [0026]    When the user activates a control to light the corresponding burner  6 , the control sends the corresponding command to an electronic driver so that it provides the necessary electrical energy to the electromagnet  36  for it to be energized, attracting the frame  37  without the need for the user to act directly on the electromagnet by having to move the frame  37  against the electromagnet  36  manually. The electronic driver provides the electrical energy necessary to attract the frame  37  towards the electromagnet  36  and keep it energized for a specific period of time while it acts on the spark plug  3  so that the necessary sparks are generated. If the flame has been lit, the thermocouple  4  is heated, generating in turn electrical energy with which the electromagnet  36  is supplied so that it remains energized while there is a flame. As soon as there is no flame or when the flame is insufficient for the thermocouple  4  to generate enough electrical energy to keep the electromagnet  36  energized, the tilting arm  38  of the actuator  20  moves into the rest position, closing the passage of gas towards the burner  6 . 
         [0027]    In a second embodiment of the gas burner, not shown as a whole in the figures, the gas burner is adapted to a household oven with grill for its operation as a conventional oven or with the grill function, comprising a casing, a thermocouple, a spark plug, an injector for supplying a gas and fixed to the casing, and a mixing conduit connected to the injector, wherein the gas that arrives through the injector is mixed with the air, of similar characteristics to the gas burner  1  described in the first embodiment and shown in  FIGS. 1 and 2 . The gas burner of the second embodiment also comprises the following additional members: a thermocouple, an injector, a spark plug, a mixing conduit and a support similar to the one described above, as a result of which they will not be described in detail. Said additional members will be used when the oven operates with the grill function. The gas burner of this second embodiment comprises a single thermoelectric safety actuator  40 , shown in  FIGS. 5 and 6 , which supplies both injectors, and is described below. 
         [0028]    The thermoelectric safety actuator  40  comprises a body  41 , 42  that has two first members  42 , similar to the first member  22  described in the first embodiment, and shown in detail in  FIG. 4 , and an intermediate member  41  arranged between both first members  42 . 
         [0029]    Each first member  42  comprises an outlet conduit  45 , while the intermediate member  41  comprises an inlet conduit  43 . According to one implementation the inlet conduit  43  is substantially orthogonal to the outlet conduits  45 . According to one implementation both the first members  42  and the intermediate member  41  are substantially cylindrical, each one of them comprising, on one end, a substantially flat contact surface  41   a,   42   a  on which first members  42  are fixed to each other by the intermediate member  41 . The intermediate member  41  comprises a groove  50  that extends along a closed contour in each of the two contact surfaces  41   a,  there being housed in said groove  50  a respective gasket  49  that seals the closure between both contact surfaces  41   a,   42   a.  The intermediate member  41  and the first members  42  each have ears  41   b,   42   b,  shown in  FIG. 6 , with respective holes through which the first members  42  are fixed to the intermediate member  41  by respective screws  52 . 
         [0030]    According to one implementation each first member  42  comprises a substantially cylindrical first housing  47  in which is partially housed an electromagnet  56  projecting out partially in relation to the support surface  42   a,  and a seating  48  that projects out in relation to the support surface  42   a  from one end of the outlet conduit  45 . According to one implementation the first housing  47  and the outlet conduit  45  are arranged substantially parallel to each other. Each injector is coupled to the outlet conduit  45  of the corresponding first member  42  of said thermoelectric safety actuator  40 . 
         [0031]    Additionally, the first housing  47  includes a first part  47   a  with a smaller cross-section in which is housed supported one end of a core  56   a  of the electromagnet  56 . In addition, the first member  42  comprises a second housing  46 , substantially coaxially to the first housing  47 , which extends from a base  42   c,  substantially parallel and opposite to the support surface  42   a,  and which is connected to the outside of the first member  42 . In said second housing  46  a connection terminal  51  is arranged inserted, connected to one end  56   d  of a coil  56   b  of the electromagnet  56 , and a gasket  53  that seals said second housing  46 . The connection terminal  51  projects out in relation to the base  42   c,  it being adapted to be connected by a respective connection terminal to the respective thermocouple. 
         [0032]    Furthermore, the intermediate member  41  comprises a housing  44  in which tilting arms  58  along with frames  57  and respective sealing members  55  are partially housed. 
         [0033]    Each tilting arm  58 , similar to the arm  38  of the first embodiment, is arranged fixed to the first member  42  by means of fixing means that comprise, in the embodiment shown in  FIG. 5 , screws  54 . Each tilting arm  58  has a fixed first part  58   a  and a second part  58   b  that is movable in relation to said first part  58   a,  the frame  57  and the sealing member  55  being arranged fixed on each end of the second part  58   b,  which, according to one implementation, is substantially flat. 
         [0034]    Each tilting arm  58  also comprises elastic means arranged between the first part  58   a  and the second part  58   b,  which allow the tilting arm  58  to be returned from the activation position, in which the corresponding frame  57  is in contact with the core  56   a  of the corresponding electromagnet  56 , to the rest position in which a substantially flat surface  55   b  of the sealing member  55  closes against a seating  48  of the first member  42  to prevent the passage of gas towards the corresponding outlet conduit  45 . The elastic means comprise a compression spring  59 , the spring  59  being arranged coupled to the first part  58   a  by a projection  58   e  and to the second part  58   b  by the corresponding projection  58   f,  as shown in  FIG. 5 . In addition, the second part  58   b  has tabs, not shown in the figures, similar to those described in the first embodiment, each one of which cooperates with a corresponding groove  58   d  that extends in the first part  58   a  in a direction substantially orthogonal to the second part  58   b,  guiding the movement and the rotation of the second part  58   b  in relation to the first part  58   a.    
         [0035]    The thermoelectric safety actuator  40  is arranged coupled to a ramp through which the gas is supplied, the gas being supplied from the respective inlet conduit  43  to the respective injector. 
         [0036]    In a third embodiment of the invention, the gas burner is similar to the one shown in  FIG. 1 , comprising the members described in the first embodiment, the thermoelectric safety actuator  20  shown in  FIGS. 1 to 4  being replaced by the thermoelectric safety actuator  60  shown in  FIG. 7  and which is described below. 
         [0037]    The thermoelectric safety actuator  60  is arranged fixed to the casing  5  and comprises an inlet gas conduit  63 , an outlet gas conduit  65 , a body  61 , 62  inside which is housed an electromagnet  76  adapted to be connected to the thermocouple  4 , a tilting arm  78  on one of the ends of which is arranged fixed a frame  77  and on the other end of which is arranged fixed a sealing member  75 , the tilting arm  78  tilting between a rest position in which the passage of gas from the inlet conduit  63  towards the outlet conduit  65  is closed by means of said sealing member  75  and an activation position, in which the electromagnet  76  is energized by the thermocouple  4  and the passage of gas is open. The electromagnet  76  is energized initially by auxiliary energization means, it being kept energized by said auxiliary energization means until the thermocouple  4  is able to keep said electromagnet  76  energized. 
         [0038]    According to one implementation the electromagnet  76  includes a core  76   a,  preferably in the shape of a U, and a single coil  76   b  wound around the core  76   a.  The frame  77  is ferromagnetic and closes against free transverse surfaces  76   c  of the core  76   a  when said electromagnet  76  is energized by the thermocouple  4 . 
         [0039]    Furthermore, the body  61 , 62  of the thermoelectric safety actuator  60  comprises a first member  62  that comprises the outlet conduit  65 , and a second member  61  that comprises the inlet conduit  63 . According to one implementation both the first member  62  and the second member  61  are substantially cylindrical, each one of them comprising a substantially flat contact surface  61   a,   62   a  on which are fixed both members  61 , 62 . The second member  61  comprises a groove  70  that extends along a closed contour on the contact surface  61   a,  there being housed in said groove  70  a gasket  69  that seals the closure between both contact surfaces  61   a,   62   a.  According to one implementation the first member  61  and the second member  62  each have ears, not shown in the figures and similar to those of the safety actuator  20  of the first embodiment, by means of which the first member  62  and the second member  61  are fixed to each other. 
         [0040]    According to one implementation the first member  62  comprises a substantially cylindrical first housing  67  in which is partially housed the electromagnet  76  projecting out partially in relation to the support surface  62   a,  and a seating  68  that projects out in relation to the support surface  62   a  from one end of the outlet conduit  65 . According to one implementation the first housing  67  and the outlet conduit  65  are arranged substantially parallel to each other. The injector  2  is arranged coupled to the outlet conduit  65  of said thermoelectric safety actuator  60 . 
         [0041]    Additionally, the first housing  67  includes a first part  67   a  with a smaller cross-section in which is housed supported one end of the core  76   a  of the electromagnet  76 . In addition, the first member  62  comprises a second housing  66 , substantially coaxially to the first housing  67 , which extends from a base  67   b  arranged on the opposite end to the support surface  62   a,  and which is connected to the outside of the first member  62 . In said second housing  66  is arranged inserted a connection terminal  71  connected to one end  76   d  of the coil  76   b  and a gasket  73  that seals said second housing  66 . According to one implementation the connection terminal  71  projects out in relation to the base  67   b,  the connection terminal  71  being adapted to be connected by a connection terminal  7   b  of a cable  7  to the thermocouple  4 , as shown in  FIG. 1 . 
         [0042]    Furthermore, the second member  61  comprises a housing  64  in which is at least partially housed the tilting arm  78  along with the frame  77  and the sealing member  75 . 
         [0043]    The tilting arm  78  is arranged fixed to the first member  62  in a similar way to that described in the first embodiment. The tilting arm  78  has a fixed first part  78   a  and a second part  78   b  that is movable in relation to said first part  78   a,  there being arranged fixed on the second part  78   b,  which is, according to one implementation, substantially flat, the frame  77  and the sealing member  75 . 
         [0044]    The tilting arm  78  also comprises elastic means arranged between the first part  78   a  and the second part  78   b,  which allow the tilting arm  78  to be returned from the activation position in which the frame  77  is in contact with the core  76   a  of the electromagnet  76  to the rest position in which a substantially flat surface  75   a  of the sealing member closes, against the seating  68  to prevent the passage of gas towards the outlet conduit  65 . According to one implementation the elastic means comprise a compression spring  79 , the spring  79  being arranged coupled to the first part  78   a  by a projection  78   e  and to the second part  78   b  by the corresponding projection  78   f.  In addition, the second part  78   b  has tabs, not shown in  FIG. 7 , similar to the tabs shown in  FIG. 3 , described in the first embodiment, each one of which cooperates with a corresponding groove  78   d  that extends in the first part  78   a,  the grooves  78   d  extending in a direction substantially orthogonal to the second part  78   b  guiding the movement and the rotation of the second part  78   b  in relation to the first part  78   a.    
         [0045]    The thermostatic safety actuator  60  also comprises an electromagnetic unit  81 , which is known in the art and will not therefore be described in detail. The electromagnetic unit  81  is arranged housed at least partially in a second housing  85  of the second member  61  of the body  61 , 62 . According to one implementation said second housing  85  is arranged substantially coaxially to the first housing  64 , the second housing  85  including a seating  84  against which it closes a sealing member  82  of electromagnetic unit  81  in a disconnection position when said electromagnetic unit  81  is not supplied with electrical energy. The electromagnetic unit  81  is arranged inserted in the second member  61 , the thermostatic safety actuator  60  including a closure member  83  that is arranged threaded to an outer surface of the second housing  85  and which keeps the magnetic unit  81  inside said second housing  85 . In this embodiment, the inlet gas conduit  63  connects to the second housing  85  of the second member  61 . According to one implementation the inlet conduit  63  is arranged substantially orthogonal to the outlet conduit  65 . 
         [0046]    The thermostatic safety actuator  60  described in this embodiment provides a double safety aspect, as firstly, when there is no flame or when the flame is not sufficient for the thermocouple  4  to generate enough energy to keep the electromagnet  76  energized, the sealing member  75  closes against the seating  68  the outlet conduit  65 , with no gas being supplied to the injector  2 , which is arranged inserted partially in the outlet conduit  65 . Secondly, in the event of a power cut, the electromagnetic unit  81  ensures the supply of gas to the injector  2  is cut, as the sealing member  82  of the electromagnetic unit  81  closes, against the seating  84 , the passage of gas towards the outlet conduit  65 . 
         [0047]    Finally, although in the embodiments shown it is the spark plug that causes the spark, in other embodiments not shown in the figures other ignition means may be used.