Abstract:
A gas safety valve with a casing having a gas inlet and a gas outlet. An electromagnet disposed in the casing is situated to act on an arm within the casing that pivots to permit gas flow through between the gas inlet and outlet when the electromagnet is energized. When the electromagnet is not energized the arm closes to impede gas flow through the valve. During normal operation a thermocouple provides power to the electromagnet to hold the valve in an open position. An auxiliary power source is also electrically coupled with the electromagnet to provide power to the electromagnet when the thermocouple generates insufficient power to maintain the valve in an open position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application relates to and claims the benefit of Spanish Patent Application No. P201030440, filed Mar. 24, 2010. 
       TECHNICAL FIELD 
       [0002]    The implementations disclosed herein relate to safety gas valves. 
       BACKGROUND 
       [0003]    There are known gas burning domestic-appliances that include thermoelectric safety devices that close the passage of gas to a burner of the appliance in the absence of a flame. Thermoelectric safety devices generally include magnetic units connected to a thermocouple, with the result that as long as there is a flame in the burner the thermocouple is heated to produce sufficient power to keep the magnetic unit energized to enable the passage of gas through the thermoelectric safety device to the burner. In the absence of a flame, the thermocouple is not heated resulting in insufficient power being supplied to the magnetic unit with the result that the magnetic unit is de-energized causing a closure of the passage of gas to the burner. 
         [0004]    Known magnetic units in the prior art comprise an electromagnet, a frame that closes against the electromagnet when the magnetic unit is energized, and a sealing member that closes the passage of gas to the burner when it closes against a corresponding seating, the sealing member being attached to the frame by a shaft. From the moment the burner is lit until the thermocouple is able to keep the magnetic unit energized a period of time elapses, with the result that the thermoelectric device must have auxiliary means which, once the magnetic unit has been reset manually, enable the magnetic unit to be kept energized until the thermocouple is able to do so by itself. 
         [0005]    Known thermoelectric safety devices are disclosed in Spanish Patent Application No. ES 0420874 A1, U.S. Pat. No. 6,886,581 B2 and U.S. Pat. No. 6,234,189 B1. 
       SUMMARY 
       [0006]    According to an implementation a thermoelectric safety actuator is provided that comprises an electromagnet that is connected to a thermocouple, a frame that closes against the electromagnet when the electromagnet is energized, a sealing member operatively coupled to the frame, which in a rest position closes against a seating preventing the passage of gas to the burner. According to one implementation an auxiliary energizing means is connected to the electromagnet and adapted to keep the electromagnet energized until the thermocouple is able to keep the electromagnet energized. In one implementation the thermoelectric safety actuator comprises a swinging arm on a first end of which the frame is arranged fixed and on a second end of which the sealing member is arranged fixed, the swinging arm swinging between a rest position, wherein the passage of gas to the burner is closed and an activation position, wherein the electromagnet is energized and the passage of gas open. 
         [0007]    As a result, a thermoelectric safety actuator is provided that may initially be energized by the auxiliary energizing means, there being no need for the user, either manually or by supplying an excessive electrical current, to reset the frame against the core of the electromagnet. The thermoelectric safety actuator is thus initially energized by the auxiliary energizing means, and kept energized by the auxiliary energizing means until the thermocouple is able to keep the electromagnet energized. 
         [0008]    According to an implementation a gas safety valve is provided comprising: a casing having a gas inlet, a gas outlet and a valve seat situated between the gas inlet and the gas outlet; an electromagnet disposed in the casing and electrically coupled to an electrical connection terminal integrated with or connected to the casing; and an arm situated within the casing that pivots between a first position and a second position, the arm biased in a first rotational direction toward the first position and having at a first end a valve member and at a second end a ferromagnetic member, when the arm is in the first position the valve member contacts the valve seat to prevent gas flow between the gas inlet and the gas outlet, upon power being supplied to the electromagnet via the electrical connection terminal the ferromagnetic member is attracted and moved toward the electromagnet to cause the arm to move in a second rotational direction opposite the first rotational direction to assume the second position, upon the arm being rotated in the second rotational direction the valve member is moved away from the valve seat to permit gas flow between the gas inlet and the gas outlet. 
         [0009]    According to an implementation a gas valve assembly adapted to supply a gas to a burner of a domestic appliance is provided, the gas valve comprising: a first flow control valve assembly comprising a first valve body having a first gas inlet, a first gas outlet and a regulatory organ situated in the valve body between the first gas inlet and the first gas outlet, the regulatory organ rotatable within the first valve body by a hand operated drive shaft to vary the flow of gas through the first flow control valve; and a second flow control valve assembly coupled to the first flow control valve assembly comprising: a second valve body having a second gas inlet coupled to the first gas outlet, a second gas outlet and a valve seat situated between the second gas inlet and the second gas outlet; an electromagnet disposed in the second valve body and electrically coupled to an electrical connection terminal integrated with or connected to the second valve body; and an arm situated within the second valve body that pivots between a first position and a second position, the arm biased in a first rotational direction toward the first position and having at a first end a valve member and at a second end a ferromagnetic member, when the arm is in the first position the valve member contacts the valve seat to prevent gas flow between the second gas inlet and the second gas outlet, upon power being supplied to the electromagnet via the electrical connection terminal the ferromagnetic member is attracted and moved toward the electromagnet to cause the arm to move in a second rotational direction opposite the first rotational direction to assume the second position, upon the arm being rotated in the second rotational direction the valve member is moved away from the valve seat to permit gas flow between the second gas inlet and the second gas outlet. 
         [0010]    In accordance with another implementation an appliance having a gas burner is provided comprising: a first flow control valve assembly comprising a first valve body having a first gas inlet, a first gas outlet and a regulatory organ situated in the valve body between the first gas inlet and the first gas outlet, the regulatory organ rotatable within the first valve body by a hand operated drive shaft to vary the flow of gas through the first flow control valve, the regulatory organ rotatable between a closed position to obstruct the flow of gas through the first flow control valve and one or more open positions to permit the flow of gas through the first flow control valve; a second flow control valve assembly comprising: a second valve body having a second gas inlet coupled to the first gas outlet, a second gas outlet and a valve seat situated between the second gas inlet and the second gas outlet; an electromagnet disposed in the second valve body and electrically coupled to an electrical connection terminal integrated with or connected to the second valve body; an arm situated within the second valve body that pivots between a first position and a second position, the arm biased in a first rotational direction toward the first position and having at a first end a valve member and at a second end a ferromagnetic member, when the arm is in the first position the valve member contacts the valve seat to prevent gas flow between the second gas inlet and the second gas outlet, upon power being supplied to the electromagnet via the electrical connection terminal the electromagnet is energized and the ferromagnetic member is attracted and moved toward the electromagnet to cause the arm to move in a second rotational direction opposite the first rotational direction to assume the second position, upon the arm being rotated in the second rotational direction the valve member is moved away from the valve seat to permit gas flow between the second gas inlet and the second gas outlet; a thermocouple situated near the burner and electrically coupled with the electrical connection terminal, the thermocouple configured to generate electrical power to energize the electromagnet upon being heated by the burner; and an auxiliary power source coupled with the electrical connection terminal. 
         [0011]    In accordance with another implementation an automatic ignition system for a gas burner in a domestic appliance is provided comprising: a thermoelectric safety valve having a valve body with a gas inlet, a gas outlet and a valve seat situated between the gas inlet and the gas outlet, an electromagnet disposed in the valve body and electrically coupled to an electrical connection terminal integrated with or connected to the valve body, the electromagnet having an upper transverse surface, an arm situated within the valve body that pivots between a first position and a second position, the arm biased in a first rotational direction toward the first position and having at a first end a valve member and at a second end a ferromagnetic member, when the arm is in the first position the valve member contacts the valve seat to prevent gas flow between the gas inlet and the gas outlet, upon power being supplied to the electromagnet via the electrical connection terminal the ferromagnetic member is attracted and moved toward the upper transverse surface of the electromagnet to cause the arm to move in a second rotational direction opposite the first rotational direction to assume the second position, upon the arm being rotated in the second rotational direction the valve member is moved away from the valve seat to permit gas flow between the second gas inlet and the second gas outlet; a thermocouple situated near the burner and electrically coupled with the electrical connection terminal, the thermocouple configured to generate electrical power to energize the electromagnet upon being heated by the burner; an auxiliary power source coupled with the electrical connection terminal; an electrical flame ignition device situated near the burner, the flame ignition device electrically coupled to the auxiliary power source and configured to produce a flame in the burner upon gas being supplied to the burner; and a switch coupled with the auxiliary power source and when acted upon by a user causes the auxiliary power source to supply power to the electromagnet and to the electrical flame ignition device for a pre-set period of time, the pre-set period of time being sufficient for the thermocouple, under normal operating conditions, to energize the electromagnet upon being heated by the burner. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  shows a perspective view of a gas valve assembly according to an implementation. 
           [0013]      FIG. 2  shows a perspective view of a thermoelectric safety actuator according to an implementation. 
           [0014]      FIG. 3  is a top view of the thermoelectric safety actuator shown in  FIG. 2 . 
           [0015]      FIG. 4  is a cross-section side view of the thermoelectric safety actuator shown in  FIG. 3  taken along the IV-IV line. 
           [0016]      FIG. 5  shows a diagram of an automatic ignition system of a burner according to an implementation. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]      FIG. 1  shows a gas valve assembly according to one implementation. The gas valve assembly includes a valve body  1  adapted to be attached to a gas burning domestic gas appliance (e.g., ovens, heaters, etc.) not shown in the figures. The gas valve assembly may comprise a drive shaft  2  adapted to connect a control device (not shown in the figures) to, for example, a conical regulation member (not visible in  FIG. 1 ) which regulates the flow of gas through the valve body  1  to the burner. The valve body  1  comprises other elements known in the art which are not described herein. The gas valve assembly also comprises a thermoelectric safety actuator  10  that prevents the passage of gas through an outlet conduit  12  and to the burner  6  in the absence of flame in the burner. 
         [0018]    According to one implementation, as shown in  FIG. 1  and also schematically in  FIG. 5 , ignition means  3  is arranged connected to the valve body  1  and functions to ignite gas in the burner  6 . In one implementation the ignition means is a spark generator. The ignition means  3  is electrically coupled to and activated by an auxiliary energizing means/power source  4 . A flame thermocouple  7  is arranged near the burner  6  and electrically coupled to the thermoelectric safety actuator  10 . 
         [0019]    The thermoelectric safety actuator  10  shown in  FIGS. 2 to 4  comprises a casing  11 , a gas outlet conduit  12  built into the casing  11 , and an electromagnet  21 . In one implementation the electromagnet  21  comprises a core  21   a , preferably U-shaped with a single coil  21   b  wound around the core  21   a . A swinging arm  22  located within the casing having a first end  22   a  with a ferromagnetic frame  20  fixed thereto, and a second end  22   b  of which a sealing member  23  is fixed. The frame  20  closes against transverse free surfaces  19  of the electromagnet  21  when the electromagnet  21  is energized. In a rest position of the thermoelectric safety actuator the sealing member  23  closes against a seating  13   a  of the gas outlet conduit  12 . The thermoelectric safety actuator  10  also comprises means  27  of returning the swinging arm  22  from an activation position, in which the electromagnet  21  is energized and the sealing member  23  is separated from the seating  13   a , to the rest position in which the sealing member  23  closes against the seating  13   a  to close the passage of gas to the burner. 
         [0020]    In one implementation the thermoelectric safety actuator  10  also comprises a metal sleeve  17  providing an electrical connection to the mass, on which is fixed the electromagnet  21 , a connection terminal  18  being arranged connected on the end opposite to the electromagnet  21 , through which the thermocouple  7  and the auxiliary energizing means  4 , shown schematically in  FIG. 5 , are connected to the thermoelectric safety actuator  10 . 
         [0021]    In one implementation the casing  11  comprises a housing  13  inside which is tightly housed the electromagnet  21 , the frame  20 , the sealing member  23  and the swinging arm  22 . In one implementation the housing  13  is delimited by a bottom surface  13   b  that includes an opening  16  passed through at least partially by the sleeve  17 , which acts as a seating of the electromagnet  21 , and by the electromagnet  21  itself, the sleeve  17  being fixed to the casing  11  through the opening  16 . In one implementation seating  13   a  is located a first distance from the bottom surface  13   b  of the housing  13  and the upper transverse surface  19  of the electromagnet  21  is spaced a second distance from the bottom surface  13   b  of the housing  13  with the second distance being greater than the first distance. According to one implementation the first distance and second distance are selected so that when the electromagnet  21  is energized a first gap between the seating  13   a  and the sealing member  23  is established to permit the passage of gas to the burner  6  and so that when the electromagnet  21  is de-energized the sealing member  23  comes against the seating  13   a  and a second gap is established between the frame  20  and the upper transverse surface  19  of the electromagnet  21 , the second gap being sufficiently small to cause the frame  20  to be drawn against the upper transverse surface  19  of the electromagnet  21  when the electromagnet  21  is energized by the auxiliary power source  4 . 
         [0022]    In one implementation fixed supports  24  are provided within the casing to support swinging arm  22 . In one implementation the fixed supports  24  are connected by means of a plate  25 , the fixed supports  24  arranged substantially orthogonal to the swinging arm  22 , as shown in  FIG. 2 . The plate  25 , which in one implementation is substantially rectangular, includes a projection  25   b  that projects out axially, on which the return means  27  is coupled. The swinging arm  22  also includes a projection  22   f  that projects out axially from a surface  22   c  of the swinging arm  22  that is arranged facing the plate  25 , the return means  27  of the swinging arm  22  being coupled with the projection  22   f . The projection  22   f  of the swinging arm  22  is arranged displaced in relation to one of the axes of symmetry of the swinging arm  22 . In one implementation the return means  27  comprises a spring, with the result that by means of the spring  27  the swinging arm  22  is arranged coupled to the plate  25 , it being capable of swinging between the rest position and the activation position. 
         [0023]    In one implementation the casing  11  of thermoelectric safety actuator  10  is fixed to the valve body  1 , for the purposes of which the casing  11  comprises on the end opposite the gas outlet conduit  12  and the opening  16 , a base  14 , the base  14  including external tabs  15 , or other means, by which the thermoelectric actuator  10  is fixed to the valve body  1 . In one implementation a seal washer (not shown) is situated within a recess  14   a  in the base  14  to provide a gas tight seal between a gas outlet in valve body  1  and the casing inlet. In various implementations the thermoelectric safety actuator  10  is configured to be fitted to the valve body  1  quickly and easily. In some implementations the thermoelectric safety actuator  10  is capable of being fitted to different types of valve bodies. The modular design also facilitates maintenance, as elements forming part of the safety actuator  10  may be easily replaced. 
         [0024]      FIG. 5  shows an automatic ignition system of a gas burning domestic appliance, which comprises the thermoelectric safety actuator  10 , the auxiliary energizing means  4  (comprising an electronic driver) connected to the thermoelectric safety actuator  10  by means of the connection terminal  18 , the thermocouple  7  connected to the thermoelectric safety actuator  10  by means of the connection terminal  18  and arranged close to the corresponding burner  6 , and ignition means  3  connected to the auxiliary energizing means  4  and arranged close to the burner  6 . 
         [0025]    According to one implementation when the user activates a control switch  5  to light the burner  6 , the control switch  5  sends the corresponding command to the auxiliary energizing means  4  so that it provides the necessary electric power to the electromagnet  21  in order to energize it, attracting the frame  20  without the need for the user to act directly on the electromagnet  21  and position the frame  20  against the electromagnet  21  manually. The auxiliary energizing means  4  provides the necessary electric power to attract the frame  20  to the electromagnet  21  and to keep the electromagnet energized for a certain period of time at the same time it acts on the ignition means  3 . If the flame has been lit, the thermocouple  7  heats up and also generates electric power with which the electromagnet  21  is supplied so that it can continue to be energized without consuming energy. The ignition system may thus be supplied initially by standard batteries. 
         [0026]    Following an initial pre-set time, the supply of electric power from the auxiliary energizing means  4  to the actuator  10  is terminated, with the result that if there is no flame or insufficient flame in the burner the swinging arm  22  of the actuator  10  is moved to the rest position, closing the passage of gas to the burner as a result of the thermocouple  7  generating insufficient electric power to keep the electromagnet  21  energized. 
         [0027]    In one implementation, in the event that the flame has gone out, the auxiliary energizing means  4  activates the ignition means  3  again in an attempt to relight the flame. If the gas in the burner does not reignite to produce a flame, the actuator  10  closes the passage of gas as a result of the thermocouple  7  producing insufficient energy to power the electromagnet  21 .