US2932348A - Ignition device for gas apparatus, particularly for gas water heaters with enclosed combustion chamber - Google Patents

Description

April 12, 1960 nij 2,932,348

IGNITION DEVICE FOR GAS APPARATUS, PARTICULARLY FOR GAS WATER HEATERS WITH ENCLOSED COMBUSTION CHAMBER Filed March 28- ,1957

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I 2,932,348 IGNITION DEVICE FOR APPARATUS, PAR- TICULARLY FOR GAS WATER HEATERS ENCLOSED COMBUSTION CHAlVIBER Hans Diinges, Remscheid,,Germany, assignor to i Joh. Vaillant K.G., Remscheid, Germany "Application March as, 1957, set-i! No. 649,029 Claims priority, application Germany April ll, 19 56 7 Claims. or. 158-115) This invention relates to an ignition deviceforgas apparatusand more particularly is concerned with such a. device to be used in gas water heaters having a. comb'us tion chamber that is enclosed withrespect tothe room of installation. f. I

It is known in the art, with suchapparatus to arrange the ignition burner in a separate chamberwhich is in :It has been found advantageous to use the slide also to Y control the ignition gas supply in any suitable manner.

A preferred embodiment'of the present invention is i1- lustrated in the'accompanying drawings and more fully explained in the following detailed description.

I In'the drawings: r Fig. l:shows an ignition trap as viewed from above;

Figs. 2' and '3 are side elevations, partly in sectional view, of the ignition trap constructed cording to the invention, and

Fig. 4 shows schematically an enclosed gas apparatus and conceived ac I and the arrangement of the ignition trap at the apparatus.

communication with both the combustion chamber and' the room of installation, these communications being realized each by an opening that can be closed by means of a hinged cover. In the well known arrangement or parts and components constituting ,such a system, 'the. hinged covers are coupled with each other by means of'a control lever in such a manner that the one cover automatically closes when the'other coverzis opened. "Such an arrangement, it is true, oifers considerable advantages over. ignition devices which etfect the: ignition from the outside throughthe closed wall of the combustion'chamher, but on the other hand, there is the disadvantage during the opening and closing process of the hinged covers .that a direct communication between the combustion chamber and the room of installation is established when the hinged covers are in their intermediate position. Since normally there exists a pressure drop between the room of installation and the combustion chamber, the .pilot flame will in many cases be extinguished by the draft which isformed due to the pressure gradient existing. The invention has therefore for its object to provide a ignition trap for such apparatus with enclosed combustion chamber that is reliable in operation and thereby to eliminate the known disadvantage described above.

- The invention starts out from an ignition burner chamber provided with openings that can be closed. In accordance with the present invention, the parts and components constituting such a system are so arranged-that the one of the openings is positively closed before the passage is admitted through the other opening. Although such a trapping action may also be realized by suitably designing the coupling members, the object of the invention may be advantageously accomplished thereby that the ignition burner is located in a housing that can be attached to the apparatus and has an opening to establish communication with the housing and the room of installation and also comprises another opening offset with respect to the first one and establishing the communication between the housing and the combustion chamber. A slide to be operated from the outside is guided in the housing and opens in its one end position one of the openings and admits passage through the other of the openings when in its other end position. The slide may be movable in axial direction or can be designed as a rotary slide. If now this slide is under the influence of a spring catch and consequently snaps from the one end position into the other when operated, sufiicient precaution is taken that the pilot flame cannot extinguish due to lack of air, as it is impossible for the slide to remain for any length of time in an intermediate position where both of the openings are closed.

. Fig. 4 shows agas apparatus 25 that is enclosedwith respect to the'room of installation 26. Freshair is suppliedto the'gas. apparatus 25 through a fresh air supply duct opening up in an opening of the wall 28. This opening 28 is covered by means of a grid 30 at the outer face of the-wall. An exhaust gas channel 29 of the gas apparatus also opens up in the same opening 28 of the wall. The mouths of the fresh air duct 27 and of the exhaust gas channel 29 are arranged close to each other, so that con-.

.stant draft. conditions result within the apparatus 25 when the wind pressure acts on the grid. Enclosed gas apparatus 'of the kind. described and the arrangement of the fresh air duct 27 and the exhaust gas channel 29 are well known in the art and are only described for sake of clarification and are not intended to form part of the object of the invention. ,xThe object proper of the invention istonly the, ignition trap 31 as necessary for such enclosed gas-apparatus, a detailed illustration of which is given in Figs. 1 to 3.

. A housing 3 is attached to the wall 1 of the combustion chamber 2 of the gas apparatus, the wall 1 of the combustion chamber being enclosed with respect to the room of 7 installation. An ignition burner nozzle 5 provided with a screw thread 4 is screwed into the housing 3. An igni-. tion burner opening 6 and an air admission opening 7 arranged diagonally opposite thereto are provided above terior space of the housing 3 with the combustion chamberv 2, the opening 8 being arranged co-axially to'the ignitionburner nozzle 5.

A hollow slide 9 guided in the housing 3 comprises a slot9" arranged inlonfgitudinal direction and provided to admit Axially arranged keys 10,110 are provided on either end of the slide and project laterally beyond the housing 3.

A spring borne click-stopball internal surface 12 of the part 13 of the housing is built into the key 10. Slide 9 has openings 14, 15 which correspond to the openings 6 and 7 of the housing 3 when 11 sliding on a double-cone the slide 9 is in its one end position as illustrated in the drawing. An axially ofiset opening 16 of the'slide 9 coincides with the opening 8 provided in the housing 3 when the slide 9 is in its other end position. Gas is supplied to the ignition burner nozzle 5 through an ignition gas channel 17 of the housing 3 in which two ignition gas valves 18, 19 are arranged that can be pushed open successively by means of an edge 20 of the slide 9. The quantity of ignition gas is adjusted by means of the throttle screws 21, 22, so that a reduced quantity of gas is admitted to the ignition burner nozzle 5 when opening the valve 18, while the normal quantity of ignition gas is supplied when the valve 19 is opened. First of all, the key 10 is only depressed slightly until the ignition gas valve 18 is opened by the edge 20. The pilot flame can now be lit up on the ignition burner nozzle 5 through the coinciding openings 6, 14. There is only a small pilot flame 23 that 0 burns inside the hollow slide 9 and receives a sufiicient Patented Apr. 12, 1960 the pa ssage of theignition burner nozzle 5..

I deepens causes ,the slide 9 to snap into itsother end position bythe covered by the slide 9 whenfin an intermediate position in which the slide cannot remain due to the clickestop device 11, 12. Simultaneously with freeing the opening 8, the ignition gas valve 19 is pushed open by the edge 20 of slide 9, so that now a greater pilot flame 24 results which protrudes through the openings 8,116 into the combustion chamber 2 and ensures a safe ignition of the burner.

I claim: s s

1. An ignition device for a gas water heater having a combustion chamber enclosed from the installation room atmosphere, comprising a housing adapted for attachment to the wall of the combustion chamber andarranged to form an ignition chamber and having a gas-fueled ignition burner fixedly positioned therein, said housing being pro vided with a passage for connection with the combustion chamber at an opening in a wall thereof and with a passage for connection with the installation room atmos-' phere; and a slide valve comprising a hollow elongated s slide member guided in said ignition chamber andcapable of being operated from the exterior of the housing, said slide member having transverse passages therein positioned to connect the ignition chamber to the combustion chamber when the slide member isat one of its terminal positions, and to connect the ignitionchamber with the installation room atmosphere 'when'the slide member-is at the other of its terminal positions, said slide valve completely closing each housing passage before 'theother' is opened, whereby a continuous passage from the installation room atmosphere through the ignition chamber to the combustion chamber is prevented.

2. An ignition device according to claim -1 wherein said ignition chamber housing is provided with an additional passage for communication with the installationroom atmosphere andsaid slide member is provided with saidslide valve is mounted non-rotatably and axially movable in said housing and is provided on either end with keys projecting axially beyond said housing.

5. An ignition device according to claim 1 and including an ignition burner gas valve mounted in the ignition chamber housing and having avalve operating member projecting into the interior of the ignition chamber and-sopositioned that movement of the slide member a small distance away from its terminal position wherein said ignition chamber is open to the room atmosphere causes said slide member to engage and depress said valve oper ating member and open said ignition burner gas valve.

6. An ignition device according to claim 1 wherein said ignition ,burner is directed to throw a flame toward said combustion chamber opening, and including a secondary ignition burner gas valve mounted in the ignition chamber housing and having a valve operating member projecting into'the interior of the ignition chamber for supplying a supplemental gas flow to the ignition burner,

said valve operating member being so positioned that when said slide member reaches its terminal position wherein said ignition chamber is open to said combustion chamber said slide member engages and depresses said valve operating member .to open said secondary ignition burner :gas valve, whereby an enlarged flame is'directed from the ignition burner into the combustion chamber.

7. ;An-ignition device according to claim 1 wherein said ignition burner is directed to throw a flame toward said combustion chamber opening and including a pair of ignition burner gas valves mounted in the ignition chamber housing, each valve having-a valve operating member projecting into the interior of the ignition chamber housing, said 'valve operating members being spaced and an additional transverse passage for cooperating withsaidadditional ignition chamber housing passage, all of saidpassages being so arranged that said ignition chamber housing passages are closed by said slide valve prior to the:

opening of the passage connecting said ignition chamber with said combustion chamber;

3. An ignition device according to claim 1 wherein a.

click-stop device is provided for maintaining said ,slide' valve normally at 'rest at either one of-its terminal so positioned that a small movement of said slide memher away from :its terminal position wherein said ignition chamber is open to the room atmosphere causes said slide member to engage'and depress one of said valve operating members to open one of said ignition burner gas valves and continued movement of said slide member to its opposite terminal position causes said slide member to'engage and depress the other valve operating member to open the other valve whereby an enlarged flame is directed from the ignition burner into the combustion chamber.

Blizard Jan. 9, 1940 FOREIGN PATENTS Great Britain Sept. 11, 1940

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