FR2837914A1 - Ignition block for blow torch comprises, nozzle to deliver ignited gas mixture, electrode to ignite mixture, earthed return electrode, gas supply jet and means of attachment/detachment to blowtorch - Google Patents

Abstract

The ignition block (1) is clipped into the main body of the blowtorch and receives gas from it through a jet (17) which also brings in air from a channel (42) by venturi effect. The gas/air mixture in the chamber (18) is ignited by live and earthed electrodes (13,14) and leaves through an ignition nozzle (10). The ignition block is controlled by a push button (2) seated in an insulated guide (23).

Description

3 0 between 0 and 30, preferably 5 and 25, more preferably

close to 15.

  S The invention relates to a biocharger and a torch equipped with such a

igniter block.

  The "air-gas" burners also called induced air burners, consist of a fuel gas supply duct, a nozzle injecting the fuel into a vacuum chamber pierced with orifices allowing the admission of the ambling air sucked in by venturi effect. The combustible gas and the aspirated air are led along a mixing channel to

  the nozzle to which the combustion flame of the mixture is attached.

  One of the known solutions for lighting such a burner is to burst an electrical spark in the gas stream passing through the burner. This solution implies that an electrical conductor, isolated from the earth of the appliance, is connected to the burner to form a first pole

  electric, the second pole being connected to the earth of the device.

  When fixing an internally ignited burner in its support or in its handle, when it is a hand-held burner, it is advisable to connect the gas supply and the electrical connection (s). This need for double connection with imperative of sealing and electrical insulation (because the voltages commonly used are of the order of 10kV) complicates the assembly.

and disassembly of the devices.

  Some existing devices have been designed to be more easily assembled and disassembled if they are complex and expensive. Document DE-A-197 45 487 describes a torch with snap on the gas supply and a spring-mounted contact to supply the ignition electrode by touching a supply ring protected by a rotating washer in which a window has been formed

passing through.

  However, this device can be mounted without ensuring electrical contact between the piezoelectric generator. As a result, ignition is impossible and unpleasant electrical leaks can also occur

in the operator's hand.

  There is also known a torch having a double connection to be screwed on one side and to be fitted on the other. However, it is heavy and its maintenance is delicate. In addition, the positioning of the electrode in the gas flow depends on the tightening of the screw connection on the gas supply and therefore, in the event of imperfect tightening, it is possible to fear gas leaks and poor ignition. The problem to be solved is therefore simply to ensure, in a safe way, the simultaneous connection of the gas circuit and the electrical circuit of a

  aero-gas burner with internal ignition.

  The solution of the invention is then an igniter block for a torch comprising: - a nozzle for delivering a combustion flame of a gaseous mixture, - an electrode opening into an internal chamber and serving to ignite an electric spark and ignite the mixture gas sent to the nozzle, - a counter-electrode, - a gas nozzle to supply the internal chamber with gas, and - a block hooking / release system making it possible to secure

  or, conversely, to separate the igniter block from a gas torch.

  Depending on the case, the igniter block of the invention may include one or more of the following technical characteristics: - it includes a venturi body arranged between the nozzle and the internal chamber. The electrode and the counter electrode are electrically isolated from each other. - the internal chamber is arranged in the block between the nozzle and the nozzle. the block attachment / release system includes means for

  fixing by screwing, snap-fastening or by elastic means.

  - the electrode is carried by an electrically insulating part.

  The invention relates, moreover, to a torch fitted with an igniter block according to the invention, in particular a torch comprising a torch body comprising at least one internal gas pipe and at least one internal electrical circuit, said pipe gas supplying gas to the nozzle and said electrical circuit supplying electric current to the electrode of a

igniter block according to the invention.

  Depending on the case, the torch of the invention may comprise one or more of the following technical characteristics: - an electrical contact is ensured between the electrode of the igniter block and the internal electrical circuit of the torch by means of a movable pusher

incorporated into the torch body.

  - sealing means ensure fluid sealing between the block

  igniter and nozzle or venturi body.

  - It includes an air inlet passage cooperating with the venturi block

  to ensure an air supply to the internal mixing chamber.

  - the igniter block is fixed integrally in a housing to the body of the

  torch configured to receive said igniter block.

  The solution of the invention guarantees the simultaneity of the connections to the gas circuit and to the electrical circuit since it is the same part which ensures the electrical contact and which holds the burner in position. This does not require any tools and uses a limited number of parts for good reliability

and a low cost.

  The corrosive provisions described here are applicable to all conventional internal-ignition or parietal spark-gap air-gas burners as described in FR 99 04586, whether they are single burners or pilot lights or igniters for torches with external ignition like the blowtorch described by

document EP-A-1 113 222.

  The rapid fixing of the igniter can be envisaged in different ways, as illustrated by FIG. 1. The igniter block 1 can be mounted or dismounted according to a simple trajectory, according to a translation along a single axis X, Y or Z. or alternatively, according to a trajectory resulting from the combination of several

  movements, in translation eVou in rotation.

  Translation along a single axis is the preferred embodiment. because of its simplicity, in particular a translational movement along the Y axis can be adopted as illustrated in FIG. 2. Thanks to this system, the two connections 101, 102 can be ensured simultaneously for the gas and the electrical connection $ le blocking in position and the release of the igniter block relative to the torch can be obtained via conventional fixing / release means (clips, means of

  screw fixing or elastic means).

  A mounting system disassembly by translation along the Z axis allows the mass and volume of the igniter block 1 to be reduced to a minimum.

  embodiment which will serve to illustrate the present invention.

  In all cases, as shown diagrammatically in FIG. 2, the igniter block 1 of the invention is fixed on the torch body 4Q (partially shown) so as to allow ignition, that is to say an inflammation of the combustible / oxidant gas mixture delivered by the main nozzle 100 of the torch, thanks to the ignition flame leaving the nozzle 10 of the block

igniter 1.

  FIG. 3 represents a device with an assembly / disassembly system along the axis Z. in which the igniter block 1 consists of a nozzle 10, a cover 11, an insulator 12, an electrode 13, a counter electrode 14, a

  venturi body 15 with seal 16 and a nozzle 17.

  In the body of the valve 4Q..e.st Mén.age ua housing 41 which receives.le lighter @ ur 1. An air inlet passage 42 is also provided to allow the venturi 15 to suck air necessary for the combustion of the gas supplying the igniter block This gas is supplied by a pipe 30

  fitting into the venturi body 15 in leaktight manner thanks to the seal 16.

  An electrical circuit 22 supplies the energy necessary to ignite the spark which will in turn ignite, in the chamber 18, the mixture of air and gas coming from the venturi body 15 when the latter is supplied by the pipe 30. The electrical circuit 22 includes an electrical source (not shown) which can be a piezoelectric generator or a circuit

electronics or transformer.

  The two poles of the spark gap which constitute the tip of the electrode 13 and the tip 141 of the counter electrode 14, are supplied, respectively, by the mass for the tip 141 and by a movable pusher 2 consisting of a tip of

button 21 and an insulating guide 23.

  The clearance between the insulator 12 and the housing 41 is made greater than the clearance between the counter electrode 14 and the housing 41 so that systematically, a frank electrical contact is established between the counter electrode 14 and the body 40 of the torch. The poin cie button 21 is supplied by a cable with high insulation 22 and the pusher which slides in its housing 43 formed in the body 40 is kept in pressure against the block 1 by a spring 24. If the block 1 is absent from its housing , the insulating guide 23 comes in

  abutment against the shoulder 431 of the housing 43.

  The ignition block is installed as follows. The block 1 is introduced along the axis Z into the body 40 of the torch, and the body 15 and the seal 16 ensure the connection of the gas circuit by fitting on the pipe 30. The shape of the surface 142 of the against elerode 14 makes it possible to push the pusher 2 back without difficulty into its housing and then to pass the insulator 12. A rotation about the Z axis makes it possible to naturally find the flat 121 whose shape can alternatively be a bowl to facilitate the indexing which finally fixes block 1 and ensures contact between the point of

button 21 and electrode 13.

  To disassemble the igniter block 17, it suffices to rotate the latter around the Z axis, which has the effect of releasing the pusher 2 from the flat 121 and authorizes the extraction of the block 1 along the Z axis. variant, illustrated in FIG. 4, the electrode 14 bis is made up of a coil making it possible to establish contact according to all the angular positions of the igniter block 1. The isolator 12 can then be a single piece overmolded on the electrode or be made up of two parts 12a and 12b assembled by bonding or simple interlocking. In this case, the materials may be dissimilar, namely a part 12a made of ceramic for example to withstand the temperature and a part 12b made of polymer to give

  flexibility and a better resistance to shock as a whole.

  In another variant, the angle formed by the igniter block 1 and the movable pusher 2 can vary for reasons of space or ease of arrangement, it is for example 90 on the figure 5, and the shape of the movable pusher can be adapted with an insulating guide 23 'which largely covers the test tip to facilitate in particular sliding, when

  - the insertion of the igniter block in the body 40.

  The advantage of this snap-fastening of an electric ignition burner also lies in the versatility of this burner which can, depending on the needs (flow rate and nature of the combustible gas, characteristics of carburation, attachment of the flame for example), receive blocks whose external dimensions are constant for mounting in the body but whose geometry of the nozzle, of the venturi of the mixing chamber or of the chamber

  are adapted to the application.

  Thus, for the torches described in EP-A-1 113 222, a standard body can be used to constitute different versions of torches suitable for different fuels, such as acetylene, propane or hydrogen for example

  simply by receiving the igniter block suitable for the fuel.

  On the other hand, a torch equipped to operate with a specific gas can very quickly be modified to operate with a different gas or

  a different application by simply replacing its igniter block.

  The present invention can also be applied to burners fed with mixtures of fuel and oxidizer (air or oxygen) as described in document EP-A-687,859. In this case, the duct gas supply receives the fuel and oxidant mixture instead of receiving the only fuel, the venturi, which no longer has any reason for being, is - removed, the mixing and combustion chambers are adapted to

  required combustion characteristics.

  The ignition module of the in \ / ention can equip the cutting torches,

welding or the like.

Claims (12)

  2. Igniter block (1) for a torch comprising: - a nozzle (10) for delivering a combustion flame of a gaseous mixture, - an electrode (13) opening into an internal chamber (18) and serving to ignite an electric spark and ignite the gas mixture sent to the nozzle (10), - a counter-electrode (14,141), - a gas nozzle (17) for supplying the internal chamber (18) with gas, and - a system for hanging the block allowing to join   or, conversely, to separate the igniter block (1) from a gas torch.   2. Block according to claim 1, characterized in that it comprises a   venturi body (15) arranged between the nozzle (17) and the internal chamber (18).   3. Block according to claim 1 or 2, characterized in that the electrode   (13) and the counter electrode (14, 141) are electrically isolated from each other.   4. Block according to claims 1 to 3, characterized in that the chamber   internal (18) is arranged in the block (1) between the nozzle (17) and the nozzle (10).   5. Block according to one of claims 1 to 4, characterized in that the   hanging system Block release includes fixing means by   screwing, snap-fastening or by elastic means.   6. Block according to one of claims 1 to 5, characterized in that   the electrode (13) is carried by an electrically insulating part (12).   7. Torch equipped with an igniter block (1) according to one of claims 1 to 6.   8. Torch comprising a torch body (40) comprising at least one internal gas pipe (3û) and at least one internal electrical circuit (22), said gas pipe (30) supplying gas to the nozzle (17) and said electric circuit (22) supplying electric current to the electrode (13) of a block   igniter (1) according to one of claims 1 to 6.   9. Torch according to claim 8, characterized in that an electrical contact is ensured between the electrode (13) of the igniter block (1) and the internal electrical circuit (22) of the torch by means of a movable pusher (2 )   incorporated into the torch body (40).   10. Torch according to the urea of claims 8 or 9, characterized in   that sealing means (16) provide a fluid seal between the   igniter block (1) and the nozzle (17) or the venturi body (15). .   11. Torch according to one of claims 8 to 10, characterized in   which it comprises an air inlet passage (42) cooperating with the venturi block (15) to ensure an air supply to the internal mixing chamber (18).   12. Gbalumeau seion i'une of claims 8 to 11, characterized in   that the igniter block (1) according to one of claims 1 to 6 is fixed   in solidarity with housing (41) body - (40-) of the configured torch