FR2745066A1 - PROTECTIVE DEVICE FOR GAS COOKING OR HEATING APPARATUS - Google Patents

Abstract

The device reinforces the safety of a gas cooking or heating appliance (1), connected to a gas distribution network (3), to a tank or to a gas cylinder, via a pipe gas supply hose (5). On the device (1) is provided at least one flame presence detector (12) associated with at least one burner (2). An electrically controlled safety valve (13) is placed upstream of the appliance (1), in particular at the start of the gas supply pipe (5), at the connection (4) to the gas distribution network ( 3), to the gas tank or cylinder. If there is no flame detected by the detector (12), an electronic control unit (9) closes the safety valve (13). Special application: gas stove.

Description

The present invention relates to a protection device, intended for

  reinforce the safety of a cooking or heating appliance, in particular a domestic appliance, using gas supplied by a distribution network, a tank or a gas cylinder as an energy source. This protective device makes it possible in particular to cut off the gas supply to the appliance, in the event of detection of a gas leak or other malfunction of the appliance or of a set of appliances,

thanks to full automation.

  A gas cooking or heating appliance is usually supplied with gas, from a fixed gas supply fitting located in the place where the appliance is installed, by means of a flexible hose. In known manner, such an appliance may comprise, associated with its gas burner (s), means capable of detecting the presence of a flame, and of controlling the closing of a safety valve integrated into the appliance, in the event when there is no flame when the appliance is placed in the on position. Such a device provides suitable security in the event of a fault occurring inside the device itself, for example if the igniter is defective. On the other hand, as is easily understood, this type of safety device is unable to provide protection in the event of faults occurring upstream of the appliance, in particular faults affecting the flexible gas supply pipe of the appliance, for example when this gas pipe has accidentally left the supply pipe of the appliance; in such a case, in fact, closing the safety valve incorporated in the device cannot prevent

  the gas outlet through the pipe which is "disconnected".

  Quite a number of accidents result, and often

very serious.

  The present invention aims to eliminate these drawbacks by providing an improved protection device for a cooking or heating & gas appliance, the proposed device ensuring total security by effectively cutting off the gas supply, whatever the location. o the fault is located, including in the case of a fault external to the device, in particular a

  fault affecting the flexible gas supply hose.

  To this end, the protective device according to the invention for a gas cooking or heating appliance, connected to a gas distribution network, to a tank or to a gas cylinder via a flexible hose d gas supply, essentially comprises in combination: - on the appliance itself, at least one flame presence detector associated with at least one burner, - upstream of the appliance, in particular from the supply pipe in gas, at the connection to the gas distribution network, to the gas tank or cylinder, an electrically operated safety valve, and - control electronics functionally connected on the one hand to or to each presence detector flame, and on the other hand to the safety valve placed upstream of the device, to control the closing

  of this safety valve in the absence of flame.

  Preferably, the control electronics are designed so as to attempt to relight the burner a predefined number of times N in the event of a flame observed by the detector, and to control the closing of the safety valve, placed upstream. of the appliance, if the flame remains absent after the N ignition attempts. Advantageously, the control electronics integrated into the device is connected to the safety valve, placed upstream of this device, in particular at the start of the gas supply pipe, by electrically conductive wires supplying and controlling this valve which pass in a space situated between the gas supply pipe proper and a protective sheath surrounding said gas supply pipe. The safety valve is thus supplied electrically, and controlled, from the cooking appliance or from

gas heater itself.

  In a variant, this safety valve, placed at the point of connection to the gas distribution network, to the tank or to the gas cylinder, may also have an electrical supply separate from that of the appliance, which may in particular be advantageous in the case of a safety valve common to several gas appliances. The safety valve can be optionally remote-controlled, the connection by electrical wires from the appliance along the gas supply pipe being replaceable by a transmission of control signals using the existing electrical supply network at the place where the device is installed, and thus superimposed on the current of the sector, or even by a

  wireless transmission (wireless or infrared).

  In all cases, a protection device is obtained, which automatically closes a safety valve placed on the gas supply connection in the place where the appliance is installed, when an absence of persistent flame is observed. , and this whatever the cause: absence of gas, defective igniter, gas pipe accidentally taken out of the supply pipe of the device. In particular, in the latter case, the position of the safety valve allows it to prevent any gas from entering the supply pipe, so that the fault (gas leak) having caused the intervention of the protective device is radically removed. It is therefore understood that the device object of the invention ensures, in such a

assumption, total security.

  In any case, the invention will be better understood at

  using the following description, with reference to the drawing

  attached schematic showing, by way of example, an embodiment of this protective device for gas cooking or heating apparatus. The only figure in the drawing shows, in perspective, a gas cooking appliance equipped with the

  protection according to the present invention.

  More particularly, this figure represents, very schematically, the hob 1 of a gas or electric / gas cooker, comprising in

  the example considered at least two gas burners 2.

  The stove is supplied with gas supplied here by a gas distribution network 3, comprising a gas supply connection 4 located at the place where the cooking appliance is installed. In a generally known manner, a flexible gas supply pipe 5 connects the connector 4 to the appliance itself. The supply of gas to the various burners 2 takes place via internal conduits 6 and is controlled by means of regulating solenoid valves 7, which

  are notably cycled solenoid valves.

  The cooking appliance also comprises keys 8, or other similar control buttons, connected to control electronics 9, itself electrically connected by conductive wires 10 and 11 to the regulating solenoid valves 7, as well as to igniters. 12 associated with the different gas burners 2. In each

  igniter 12 is incorporated a flame detector.

  According to the invention, an electrically operated safety valve 13 is placed inside a housing

  14, from the gas supply pipe 5, that is to say

  say at the gas supply connection 4. The safety valve 13 is electrically connected to the control electronics 9 by conductive wires 15 which pass into a space 16 situated between the gas supply pipe 5 proper and a protective sheath 17 surrounding this supply pipe 5, over its entire length from the housing 14 to the cooking appliance. As regards the safety valve 13, it may be a normally closed solenoid valve, comprising a needle pointed by a spring towards an annular seat, the electrical supply of the coil of this solenoid valve being necessary to control and

keep it open.

  During normal operation of this cooking appliance, the safety valve 13 is kept in the open position. The normal operating condition is noted, for the or each gas burner 2 put into service, by the associated flame detector located at 12, cooperating with

the control electronics 9.

  If a flame detector located at 12 detects an absence of flame, while the corresponding burner 2 has been placed in the on position by pressing the corresponding control button 8, the system attempts to relight this burner 2 a number of times N predefined. If after N re-ignition attempts, the detector located at 12 observes the persistence of the absence of flame, the control electronics 9 causes, through the electrical wires 15, the closing of the safety valve 13. Any arrival gas to the stove is

thus interrupted.

  In particular, in the case of an absence of flame resulting from a gas leak at the flexible gas supply pipe 5, the closing of the safety valve 13 located at the starting point of this pipe 5 makes it possible to immediately remove this leak, and ensure

thus total protection.

  In view of the above, the invention is more particularly applicable to a gas cooking or heating appliance, the entire operation of which is managed automatically, by control electronics 9 combined with the use of solenoid valves. of

regulation 7.

  It goes without saying that the invention is not limited to the only embodiment of this protective device for a gas cooking or heating appliance which has been described above, by way of example; it embraces, in content, all variants of implementation and application respecting the same principle. In particular, one would not depart from the scope of the invention by modifying the internal structure of the safety valve, or by applying the same device to any apparatus for

  gas, regardless of the number of gas burners, and regardless of the source of gas: supply network, tank or gas cylinder.

Claims (4)

  1. Protective device for a gas cooking or heating appliance (1), connected to a gas distribution network (3), to a gas tank or cylinder by means of a flexible hose. gas supply (5), characterized in that it essentially comprises, in combination: - on the appliance (1) itself, at least one flame presence detector (12) associated with at least one burner (2 ), - upstream of the appliance (1), in particular from the gas supply pipe (5), at the connection (4) to the gas distribution network (3), to the tank or to the bottle gas, an electrically controlled safety valve (13), and - control electronics (9) functionally connected on the one hand (at 11) to or each flame detector (12), and on the other part (in) to the safety valve (13) placed upstream of the device (1), to control the closing of this valve   safety (13) in the absence of flame.   2. Protection device for a gas cooking or heating appliance, according to claim 1, characterized in that the control electronics (9) is designed so as to attempt to relight the burner (2) a number of times N predefined in the absence of flame observed by the detector (12), and to command the closing of the safety valve (13), placed upstream of the device (1), if the flame remains absent at the end N ignition attempts.   3. Protection device for a gas cooking or heating appliance, according to claim 1 or 2, characterized in that the control electronics (9) integrated into the appliance (1) is connected to the safety valve ( 13), placed upstream of this device (1) in particular from the gas supply pipe (5), by electrically conductive wires (15) supplying and controlling this valve (13) which pass through a space (16) located between the gas supply pipe (5) proper and a protective sheath (17) surrounding said supply pipe gas (5).   4. Protection device for a gas cooking or heating appliance, according to claim i or 2, characterized in that the safety valve (13) has an electrical supply separate from that of the appliance (1).