GB1584375A

GB1584375A - Gas valve

Info

Publication number: GB1584375A
Application number: GB3877577A
Authority: GB
Original assignee: Joh Vaillant GmbH and Co
Current assignee: Vaillant GmbH
Priority date: 1976-09-17
Filing date: 1977-09-16
Publication date: 1981-02-11
Also published as: JPS5836223B2; NL172889B; FR2365069A1; AT383659B; FR2365069B1; ATA648277A; DE7629484U1; JPS5337917A; NL7710104A; NL172889C

Description

(54) GAS VALVE (71) We, JOH. VAILLANT KG, a Company the Federal Republic of Germany residing at 5630 Remscheid, Postfach.

10 10 20, Berghauser Strasse 40, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to a gas valve.

According to the invention we provide a gas valve comprising a housing that includes a first valve seat for a large flow of gas and a second valve seat for a small flow of gas provided with an associated valve body pretensioned by a wire snap means, said small flow valve seat and valve body being in a common sleeve that carries a hollow cylindrical body having on its outside a circumferential projection and a seal for said first valve seat and an internal safety valve seat, said hollow cylindrical body having a sealing body that cooperates with an insert body inserted in said housing, the insert body being provided with slots on the inside thereof that are progressively opened or closed by respective movement of the said sealing body.

The invention will be more fully understood from the following description given by way of example only with reference to the figures of the accompanying drawings, in which: Figure 1 is an axial cross-section through a whole gas valve; Figures 2 and 3 are cross-section and plan respectively in first angle orthographic projection of a part of the gas valve of Figure 1.

In all three figures the same reference numerals designate the same integers.

Referring now to the figures of the drawings a housing of a gas valve for a flow-through water heater is shown generally at 1 and has a lower part 2 and an upper part 4 attached thereto by means of a screw thread 3. The lower and upper parts 2, 4 have end threads respectively St, 52 by which rhe housing can be mounted in a gas line (not shown).

Inner wall 6 of the housing is of right cylindrical form and circular section and it has ribs 7. An annular shoulder 8 provides a large flow valve having a first valve seat 9 in the inner wall 6 that cooperates with a large annular seal ring 17 preceded by a guide section 10 delimited by a shoulder 11 and a groove 12.

In the interior 13 of the housing a hollow cylindrical body 14 is supported having a circumferential projection 15 guided against the ribs 7. The projection 15 is under the influence of a helical compression spring 16 which, in turn, is supported against an under surface of the upper part 4 of the housing 1.

The spring 16 presses the hollow cylindrical body 14 against the seat 9 of the large flow valve via the intermediary of the large seal 17.

In its lower area 18 the hollow cylindrical body 14 has an annular groove 19 into which is mounted a lip seal 20 in the form of a ring. This lip seal 20 cooperates with the internal wall of an insert body 21 being supported in the guide section 10 of the lower part of the housing 2 with the interposition of an 0-ring 22 and having diametral projections 231, 232 (Figure 3) which engage in the groove 12. The side 21A of the insert body 21 facing the interior 13 has slots 24 which, depending on the position of the lip seal 20, are more or less covered.

At its upper end the hollow cylindrical body 14 has an internal thread which is screwed onto the external thread of a sleeve 25 representing a bell-shaped, hollowcylindrical unit. A cover piece 28 having a gas nozzle 27 is screwed into the sleeve 25.

In the interior 29 of the sleeve 25 there is supported a wire snap 30 cooperating with a circumferential projection 31 in the sleeve 25. At an inner wall 32 of the sleeve 25 a hollow cylindrical holding body 33 carrying a supporting body 35 via a flanged connection 34 is provided. By means of the flanged connection 34 also a ring 36 is held against the body 33 which ring supports a spring 37 which has its free end abutting against a further ring 38. The ring 38 cooperates both with a projection of the holding body 33 and also with an inner shoulder of the sleeve 25 so that in a position of rest the holding body 33 is pretensioned with respect to the sleeve 25.

The supporting body 35 has a central inner recess 39 in which a plunger 40 is guided against the restoring force of a spring 41. The plunger 40 has attached thereto a valve body 42 which cooperates with a second valve seat 43 and seal ring 43A which, in turn, constitutes part of the holding body, this valve gives a small flow path for the gas and is the small flow valve.

At the underside of the sleeve 25 is a ring 44 which acts as a spring plate for helical compression spring 45 against another spring plate 46A integral with safety valve body 46. Seat 47 cooperates with the saftey valve body 46 and this seat 47 is constituted by the inner wall of the hollow cylindrical body 14 and coacts with a seal ring 46B.

The upper side 48 of the safety valve body corresponds in diameter to the underside diameter of the supporting body 35, normally in use there is a spacing 49 between the facing sides of 48 and 35.

An internal through-bore 50 contains a screw 51 which has an inner recess that engages an actuating rod 52 of a water safety device (not shown) provided with a sensor (not shown). The rod 52 has first to overcome an idling distance 53 before contacting the screw 51.

The modus operand of the gas valve is as follows: In the state of rest illustrated in Figure 1 all valves are closed.

Now, if a water valve (not shown) is opened, water current flows through the heat exchanger of the heat source (not shown).

The water current is detected by a water safety device and depending on the volume of water, so the actuating rod 52 is moved in the bore 50 of the screw 51. After having overcome the idle stroke distance 53 the rod 52 contacts the screw 51 and the safety valve body 46 is lifted from its seat 47 against spring 45. Consequently, the interior 29 internally of the sleeve 25 is in connection with the lower opening in the housing 1 of the gas valve and the gas supply entering at arrow A. However, no gas can yet pass to the burner connected to the upper outlet 4A of the top part 4 of the housing 1 since the gas valve 42, 43, 43A is still closed. After opening of the safety valve, i.e. lifting of the valve body 46, the upper side thereof 48 contacts the underside of the supporting body 35 after having overcome the distance 49.Together with the supporting body 35 also the holding body 33 is lifted. This lifting is accomplished against spring 37. The holding body 33 forces the wire snap 30 against the projection 31 until the wire snap 30 is reversed when the free ends of the wire snap 30 force the plunger 40 downwardly, the valve body 42 of the wire snap being carried along and thus lifted from its seat 43. Now, the small flow path to the gas burner is open and the gas of the small flow path flows through the interior 29 and out of the gas nozzle 27 (arrow B). During further lifting of the rod 52 the hollow cylindrical body 14 is lifted against spring 16 in such a manner that the large flow valve 15, 9 opens. The further path of the rod 52 is proportional to an increase in the flow of the water and the gas stream is increased accordingly to give a constant temperature of the discharged water.When the hollow cylindrical body 14 is lifted, the lip seal 20 moves over the insert body 21 and releases the slots 24 more or less so that during the upward rise of the hollow cylinder body 14 an increasing gas stream is supplied to the heat source. This process is terminated at a specific rate of water flow to which a specific rate of gas is proportional.

The closing movement of the described gas valve is effected in reverse sequence, mutatis mutants.

From Figures 2 and 3 it is clear that the individual slots 24 of the insert body 21 can have differently inclined parts (angle ez) with different width xo and heights h.

These different slot arrangements serve for individual adaption of the insert body 21 to the respectively required conditions of the individual heat sources. By the projections 23 on the insert body 21 it is ensured that the whole body 21 is mounted in the housing 1 and can be withdrawn downwardly of the housing, removed and exchanged after the projections 231, 232 have been pressed diametrally inwardly.

WHAT WE CLAIM IS: 1. A gas valve comprising a housing that includes a first valve seat for a large flow of gas and a second valve seat for a small flow of gas provided with an associated valve body pretensioned by a wire snap means, said small flow valve seat and valve body being in a common sleeve that carries a hollow cylindrical body having on its outside a circumferential projection and a seal for said first valve seat and an internal safety valve seat, sated hollow cylindrical body having a sealing body that cooperates with an insert body inserted in said housing, the insert body being provided with slots on the inside thereof that are progressively opened or closed by respective movement of the said sealing body.

2. The gas valve according to Claim 1 wherein the insert body is provided with

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. against the body 33 which ring supports a spring 37 which has its free end abutting against a further ring 38. The ring 38 cooperates both with a projection of the holding body 33 and also with an inner shoulder of the sleeve 25 so that in a position of rest the holding body 33 is pretensioned with respect to the sleeve 25. The supporting body 35 has a central inner recess 39 in which a plunger 40 is guided against the restoring force of a spring 41. The plunger 40 has attached thereto a valve body 42 which cooperates with a second valve seat 43 and seal ring 43A which, in turn, constitutes part of the holding body, this valve gives a small flow path for the gas and is the small flow valve. At the underside of the sleeve 25 is a ring 44 which acts as a spring plate for helical compression spring 45 against another spring plate 46A integral with safety valve body 46. Seat 47 cooperates with the saftey valve body 46 and this seat 47 is constituted by the inner wall of the hollow cylindrical body 14 and coacts with a seal ring 46B. The upper side 48 of the safety valve body corresponds in diameter to the underside diameter of the supporting body 35, normally in use there is a spacing 49 between the facing sides of 48 and 35. An internal through-bore 50 contains a screw 51 which has an inner recess that engages an actuating rod 52 of a water safety device (not shown) provided with a sensor (not shown). The rod 52 has first to overcome an idling distance 53 before contacting the screw 51. The modus operand of the gas valve is as follows: In the state of rest illustrated in Figure 1 all valves are closed. Now, if a water valve (not shown) is opened, water current flows through the heat exchanger of the heat source (not shown). The water current is detected by a water safety device and depending on the volume of water, so the actuating rod 52 is moved in the bore 50 of the screw 51. After having overcome the idle stroke distance 53 the rod 52 contacts the screw 51 and the safety valve body 46 is lifted from its seat 47 against spring 45. Consequently, the interior 29 internally of the sleeve 25 is in connection with the lower opening in the housing 1 of the gas valve and the gas supply entering at arrow A. However, no gas can yet pass to the burner connected to the upper outlet 4A of the top part 4 of the housing 1 since the gas valve 42, 43, 43A is still closed. After opening of the safety valve, i.e. lifting of the valve body 46, the upper side thereof 48 contacts the underside of the supporting body 35 after having overcome the distance 49.Together with the supporting body 35 also the holding body 33 is lifted. This lifting is accomplished against spring 37. The holding body 33 forces the wire snap 30 against the projection 31 until the wire snap 30 is reversed when the free ends of the wire snap 30 force the plunger 40 downwardly, the valve body 42 of the wire snap being carried along and thus lifted from its seat 43. Now, the small flow path to the gas burner is open and the gas of the small flow path flows through the interior 29 and out of the gas nozzle 27 (arrow B). During further lifting of the rod 52 the hollow cylindrical body 14 is lifted against spring 16 in such a manner that the large flow valve 15, 9 opens. The further path of the rod 52 is proportional to an increase in the flow of the water and the gas stream is increased accordingly to give a constant temperature of the discharged water.When the hollow cylindrical body 14 is lifted, the lip seal 20 moves over the insert body 21 and releases the slots 24 more or less so that during the upward rise of the hollow cylinder body 14 an increasing gas stream is supplied to the heat source. This process is terminated at a specific rate of water flow to which a specific rate of gas is proportional. The closing movement of the described gas valve is effected in reverse sequence, mutatis mutants. From Figures 2 and 3 it is clear that the individual slots 24 of the insert body 21 can have differently inclined parts (angle ez) with different width xo and heights h. These different slot arrangements serve for individual adaption of the insert body 21 to the respectively required conditions of the individual heat sources. By the projections 23 on the insert body 21 it is ensured that the whole body 21 is mounted in the housing

1 and can be withdrawn downwardly of the housing, removed and exchanged after the projections 231, 232 have been pressed diametrally inwardly.

2. The gas valve according to Claim 1 wherein the insert body is provided with

a projection that engages in a groove in the housing releasably pretain the insert therein.

3. The gas valve according to Claim 1 or Claim 2, wherein the slots have any suitable form to give a progressively larger or smaller opening with the opening and closing respectively of the slot by means of the movement of the sealing body.

4. A gas valve constructed and arranged substantially as herein described and as shown in the figures of the accompanying drawings.