US2343904A

US2343904A - Safety ignition device for gas

Info

Publication number: US2343904A
Authority: US
Publication date: 1944-03-14
Anticipated expiration: 1961-03-14

Description

March 14, 1944. HEGWE 2,343,904

SAFETY' IGNITION DEVICE FOR (ms BURNERS v Filed Feb.' 27, 1939 5 Sheets-Sheet 1 Jaye/2MP:

March 14, 1944. HEGWElN 2,343,904

SAFETY IGNiTION DEVICE FOR GAS BURNERS Filed Feb. 27. 1959 5 Sheets-Sheet 2 u: 23 f; 25 I Jarenfar:

Filed-Feb. 27; 1939 5 Sheets-Sheet 3 March 14, 1944. HEGwEm 2,343,904

SAFETY IGNITION DEVICE FOR GAS BURNERS Filed Feb. 27, 1939 5 Sheets-Sheet 4 I 23 v V 40 March 14, 1944. HEGwEjN 2,343,904

SAFETY IGNITION DEVICE FOR GAS BURNERS Filed Feb. 27, 1939 5 Sheets-Sheet 5 Patented Mar-.14, 1944 UNITED STATES PATENT oFFu:

SAFETY IGNITION DEVICE FOR GAS BURNERS Georg Hegwein, Dessau, Germany; vested in the Alien Property Custodian Application February 27, 1939, Serial No. 258,83 In Germany March 8, 1938 17 Claims.

The invention relates to a safety ignition device for gas burners in which the supply of gas to the pilot flame and main burners is controlled by a thermostat heated by the pilot flame.

In previously proposed arrangements of this kind the main gas valve and pilot flame valve have been connected with a control rod actuated by the thermostat in such a manner that on the thermostat becoming heated the main gas valve is opened and the supply of gas to the pilot flame is throttled whilst on-the-othenhand when the thermostat cools down the main gas valve is closed and the pilot flame valve opened. In

. such case, although the supply of gas to the It is an object of the invention to provide a thermostatically controlled safety ignition device for gas burners having means for controlling the supply of gas to the pilot flame and main burner.

Another object of the invention is to provide a safety ignition device wherein the pilot flame valve and the main gas valve are opened in succession after a predetermined interval.

A further object of the invention is to provide an arrangement wherein in the event of the extinction of the pilot flame the gas supply to the main burner and to the pilot flame are cut off.

It is a still further object of the inventionto provide an ignition device for a gas burner wherein a single thermally responsive device is adapted to actuate both the pilot flame valve and the main gas valve.

It is a still further object to provide a gas burner ignition device which is adapted to be set in operation by a manually operated press knob and having means whereby the gas supply to the main burner and pilot burner are thereafter automatically regulated;

Other objects of the invention willappear from the following description and appended claims when considered in connection with the accompanying drawings forming part of this specification.

According to the present inventionthe valves for supplying gas to the pilot flame and main burner are so arranged and combined with the control device actuated by the thermostat that when the thermostat is heated the valve for the' pilot flame gas and that for the main supply open in succession after a predetermined lapse of time and are closed in reverse order when the thermostat cools down.

' The result of this arrangement is that after the extinction of the pilot flame the supply of gas both to the main burner and the pilot flame is cut off. In this case the pilot flame nozzle may have acomparatively wide bore so that the troublesome choking due to gum is obviated and a rapid uninterrupted flow of gas through the pilot flame pipe accompanied by accelerated opening and thereforerapid control action of thedevice is obtained.

To enable the invention to be fully understood it will now be described with reference to the accompanying drawings in which five typical embodiments of the invention are illustrated in Figs. 1-5, which are longitudinal sectional views. in all these embodiments substantially corresponding parts are indicated by the same reference numerals.

-The safety ignition device according to Fig. 1 comprises a casing I, with .a branch 2 for connection with a gas-supply pipe and a branch 3' ror connection with the main burner. Arranged on the casing I is a thermostat 4 composed of a bimetallic strip, the free end of which is connected with a control rod 5 axially displaceable I in the casing I. Said rod 5 rests on the head 6 or a coaxially arranged thrust rod 1 adapted to slide in a valveplate 8. The plate 8 is held in the closed position by a spring 9 and is provided on its lower end with a tubular extension H provided with transverse bores l0 and is slidably guided on a tube I2 adapted to be axially displaced by means of a push knob l3 (against the action of a spring M) in a guide member l5 which is screwed into the casing I. At the same I time the stroke of the tube I2 is preferably restricted by suitable means. At the end facing the knob l3 the tube I2 'is fitted with a gastight packing and is provided at its upper end with an opening l6 below which is located inside the tube a ball valve I! held in the closing position by a spring l8. The ball valve ll faces the lower end of the thrust rod I through the opening IS with or without a predetermined amount of lost motion. Below the tubular extension ll of the valve plate 8 the guide member I is provided with a valve'seating IQ for the tube I2. The guide member I5 is provided with a horizontal bore 20 extending right through and communicating with the valve seating 19 through a widened bore 2| and with the interior of the tube I2 through bores 22. A tube 23 leading to the pilot flame nozzle 24 also communicates with the bore 20.

The arrangement according to Fig. 1 functions in the following manner: When the various parts are set in the positions shewn in Fig. 1 the arrangement is in the inoperative position. To set it in operation an upward pressure is applied to the knob l3. By this means the tube [2 is correspondingly raised from the valve seating I9 so that the gas entering through the branch 2 can flow past the valve seating I9, bores 2| and 20 and the tube 23 of the pilot flame nozzle 24. Raising the tube l2 by means of the knob l3 also causes the ball valve I! to be opened but ince the tub 12 also closes the bores H) the opening of the valve I1 is inoperative for admitting the gas to the pilot flame nozzle. Consequently the supply of gas to the pilot flame burner 24 takes place at first only by way of the valve seating 19 in the manner already described.

If the gas issuing from the nozzle 24 be now ignited the pilot flame heats the bimetallic strip 4, the free end of which then depresses the con trol rod 5 and therewith the thrust rod 1 which opens the ball valve ll more fully against the action of the spring l8. After a short interval the knob l3 may be released whereupon it is returned to its original position by the spring l4. At the same time the tube I2 also is returned into its original position to seat on the valve seating 19. However, since the tub l2 has again uncovered the transverse bores I0 in the tubular extension ll of the valve plate 8 and the thrust rod 1, correspondingly depressed by the thermostat 4 keeps the ball valve I! open, gas is now supplied to the pilot burner nozzle 24 through the bores ID, the ball valve l1 and the bores 22 of the tube l2 and the bore 20 communicating with the tube 23 so that the pilot flameis not interrupted.

The continued heating of the thermostat 4 by the pilot flame depresses the control rod 5 still further so that the head 8 of the thrust rod 1 bears against the valve plate 8 and moves it from; its seating against the action of the spring 9. In this'way gas is also admitted to the main burner connected with the branch 3 and this gas is then ignited by the pilot flame in known manner.

when the valve plate 8 is depressed by the head 6 the'bores I0 provided in the tubular extension l I of the valve plate also occupy a correspondin ly lower level and thus become more or less covered by the upper end of the tube 12.,

The supply of gas to the pilot flame nozzle 24 is thus throttled in such a manner that the pilot flame continues to burn with only just suflicient power to keep the valve plate I in the openposition. It the gas supply to the nozzle 24 be insufllcient to enable this condition to be maintained the valve opening action of the thermostat 4 will diminish and the valveplate 8 will be lifted by the spring 8. Thefree aperture otthe bores ll will thus increase accordingly so that the supply of caste the pilot flame male 24 is increased and the more highly heated thermostat will depress the valve plate 8 accordingly against the action of the spring 9. Consequently the supply of gas to the nozzle 24 and the main burner is regulated automatically.

If the knob l3 be held too long in the upward position the pilot flame burner 24 will receive an undiminished supply of gas owing to the tube i2 being maintained above the valve seating IS. The thermostat 4 will therefore be intensely heated and thus exert a powerful downward pressure on the valve plate 8. The opening stroke of the plate 8, however, is limited by the tubular attachment H, the lower end of which seats itself on a corresponding flat surface of the guide member I5 and thus interrupts the supply of gas past the valve seating l9 so that the pilot flame goes out. This arrangement prevents, therefore, the thermostat 4 from becoming damaged.

If the pilot flame be extinguished and the heating of the thermostat thus ceases the free arm of the thermostat 4 returns to its original position, the valve plate 8 being returned to its original closing position by the spring 9 and the ball valve I'I similarly closed by the spring I8 so that the supply of gas is shut' off from the main burner and also the pilot burner nozzle 24.

The arrangement of the transverse bores I0 for supplying gas to the pilot burner nozzle is noteworthy. These bores are comparatively wide and are arranged in such a manner as to be partially covered by the upper part of the'tube l2 even when in the inoperative position. The result of this arrangement is that a sufilcient aperture for the supply of gas is normally available whilst even a comparatively slight lowering of the valve plate 8 from its seat is enough to throttle the supply of gas to the nozzle 24 considerably. The possibility is also afforded of providing the pilot burner nozzle with a comparatively wide aperture which as already mentioned is of advantage in many respects.

Owing to the relatively slidable telescopic tubular members i l and i2 for controlling the sup- .ply of gas the structural height of the entire arrangement can be kept low and the design as a whole made comparatively simple.

The arrangement according to Fig. 2 differs from that described with reference to Fig. 1 flrstly in that the ball valve l7 and its closing pring iii are located in a fixed (and not slidable) tube 25 which for example is integral with a closure member 25 adapted to be screwed into the casing I. The free space in which the spring I8 is situated communicates with the tube 23 supplying gas to the pilotburner nozzle 24 by way of a bore 21 in the member 26 and a passage 28 in the casing i. In this case the gas is supplied to the main burner by a branch 3 attached to the space above the valve plate 8." To make the arrangement ready for lighting up, the casing I is provided with a press knob 29 adapted to be depressed against the action of an inte riorly housed spring (not shown). Said knob has a widened rim 30 which when the knob is depressed depresses the control rod 5 and therefore the thrust rod 1 accordingly. In this'way the ball valve I1 is opened so that in contrast prolonged actuation of the knob will not affect the functioning of the arrangement.

When made ready for lighting. up, the arrangement according to Fig. 2 functions in precisely the same manner as that according to Fig.1.

The arrangement according to Fig. 3 corresponds with that according to Fig. 2 in so far that in this case also a press knob 29 is provided on the casing for preparing the conditionsfor lighting up.

According to Fig. 3 the gas is supplied through a branch 2 arranged on the rear side of the example shewn. The main'burner is connected with the branch 3. The ball valve l1 and its closing spring I8 are housed in a fixed tube 3| which is integral with a diaphragm housing 32 screwed into the lower end of the casing cated in the lower end of the tube 3| is a second ball valve 33 whilst similarly to the case of Fig. 2 the interior space of the tube 3| communicates with the tube 23 supplying gas to the pilot burner 11 zzle 24 through bores 34 in the diaphragm hens and a passage 35 in the casing i. The housing 32 is provided with a diaphragm 36 which when in the inoperative position is pressed upwards by a spring 31 and thus keeps 4| and thus controls the supply of gas passing in the first place through the

passages

44, 45, 46 and tube 23 to the pilot-bumer nozzle 24. Also branching from the tube 4| is a passage 41 to which is attached a tube 48 the other end of which communicates with the passage 45. A known instrument 49 for automatically controlling the supply of gas through the tube 48 in accordance with the room temperature is located at a suitable point in said tube 48.

The arrangement according to Fig. 4 functions 1 in the following manner. After making ready for lighting up by depressing the knob 29 the gas supply to the pilot burner nozzle 24v proceeds by way of the bores |0, the opened ball valve H, the tube 4| and the

passages

43, 44, 45 and 43. After the thermostat 4 has become hot enough to cause the head 6 of the thrust rod 1 to move the valve plate 8 from its seating, the volume control pin is also depressed sufllciently to close the bore 43. The supply of gas to the pilot burner nozzle 24 now takes place by way of the passage 41, tube 48 and

passages

45, 45 The control instrument 49 which is set to act at a predetermined temperature now controls the supply of gas to the pilot burner nozzle in known manner, the supply the ball valve 33 open by means of a pin 38 adapted to slide axially in the diaphragmhousing.

Beyond the main valve plate 8 the conduit sup-' plying gas to the main burner is placed in communication with the space above the diaphragm 36 through a passage 39.

The arrangement according to Fig. 3 functions in the following manner: Making ready for,

38 shares the movement of the diaphragm thus more or less lowering the ball valve 33 so that under the action of the spring |8 the supply of gas to the pilot burner is correspondingly throttled by the valve 33. The resulting lowering of the pilot flame and the consequently diminished heating of the thermostat 4 adjusts the valve plate 3 in such a manner that the gas pressure in the supply pipe for the main burner is main-.

tained at a predetermined constant level that v is to say the supply of gas to the main burner is automatically controlled in accordance with the 888 DI'GSSIIIB.

Fig. 4 represents an arrangementin which the gas supply is controlled in accordance with a predetermined temperature such as room temof gas to the main burner being thus controlled by the corresponding adjustment, already described with reference to Fig. 2, of the valve plate 8 by the thermostat 4'. I I

The arrangement according to Fig. 5 differs in the first place from that according to Fig. 2 in I that the tubular extension of the valve plate 3 is perature. By comparison with the arrangement according to Fig. 2 that shewn in- Fig. 4 differs in respect of the design of the lower portion- In the case of Fig. 4 this portion comprises an attachment 40 which is screwed into the casing and is integral with a tube 4| housing the ball valve II. In this case the ball valve-l1 rests on a volume control pin '42 which, when the arrange-.

ment is out of. action. is lifted bythe spring IS in such amanner as to hold the ball valve I! in the closed position. The lower end of the pin 42 of the tube 50 communicates with the nozzle 24 in a similar way to the arrangement according to Fig. 2.

The arrangement according to Fig. 5 functions in the following manner. a The arrangement is made ready as in the case of Fig. 2. If now, as

theresult of the thermostat becoming too inbe automatically controlled in a manner otherwise corresponding with Fig. 2.

I In its manner of operating, the device for controlling the supply of gas to the pilot burner in the arrangement according to Fig. '5, corresponds with the volume'control pin 42 actuated by the pilot flame valve l1 and coacting with a bore 43, according to Fig. 4. Consequently in the "case also of the arrangement according to Fig. ,4,

the tubular extension l| employed in connection with the main gas 'valve 8 for controlling the gas supply to the pilot flame could be, omitted I claim: g 1. A safety ignition device .for gas burners comprising a pilot-flame valve, a main gas valve,'a thermostat adapted to be heated by the pilot flame, a control device actuated by said thermostat, said control device directly engaging and operating said valves so that, when the thermowith means for progressively throttling of the pilot gas when the main gas valve is moved by the thermostat beyond its completely open position.

2.-A device according to claim 1 wherein the main gas valve comprises a valve plate which is retained in the closed position by a spring whilst the pilot-flame gas valve consists of a ball valve which is retained in the closing position by a spring, the two valves being independently slidable in the same axial direction and opened or closed by movement in the same direction.

3. A device according to claim 1 wherein a control rod actuated by the thermostat acts on a thrust rod, one end of which passes through the main gas valve and actuates the pilot-flame valve, whilst its other end is provided with means adapted to actuate the main gas valve.

4.-A device according to claim 1 whereinthe pilot-flame valve is housed in a tube and the tubular means is slidably mounted by said tube.

5. A device according to claim 1 wherein the pilot-flame valve is housed in a tube and said tubula means is slidably mounted by said tube, said openings being arranged so as to be correspondingly more or less covered by the tube as themain gas valve is opened.

6. A device according to claim 1 wherein the pilot-flame valve is housed in a tube and said tubular means is slidably mounted on said tube, said openings being of comparatively large cross section and being arranged in such a manner as to be partially covered by the tube even when the device is in the inoperative position.

7. A device according to claim 1 wherein a press knob device is provided which is operated to open a supplemental supply of gas' to the pilot flame in order to set the device in operation.

8. A device according to claim 1 wherein the pilot-flame valve is housed in a tube and said tubular means is slidably mounted on said tube, the tube housing the pilot flame valve being mounted so as to be axially displaceable by means of a press knob against the action of a spring, an auxiliary valve being provided for a supplemental supply of gas to the pilot flame, this latter valve being against the control device actuated by the thermostat in such a manner as to open the pilotflame valve. 1

10. A device according to claim 1 wherein the pilot-flame valve is housed .in-a tube and said tubular means is slidably mounted on said tube, a second valve being located in the tube housing the pilot-flame valve and by means of 2. diaphragm pressure regulator attached to the casin controls the supply of gas to the pilot-flame burner in accordance with the gas pressure prevailing in'the'gas supply pipe to the main burner.

valve in the tube housing the latter by means of which the pilot-flame valve is adapted to throttle the supply of gas to the pilot flame when in the fully open position.

12. A device as set out in claim 1 including an auxiliary valve controlling a supplemental supply of gas to the pilot flame, and a manually operated device for actuating said auxiliary valve.

13. A safety ignition device for gas burners having a pilot flame valve, a main gas valve, a thermostat adapted to be heated by said pilot flame, both valves being operable by said thermostat, a rod connected to said thermostat for actuating said valves, said rod being in constant positive connection with said pilot flame valve and having means which are brought in positive connection with said main gas valve to actuate it after the rod has opened the pilot flame valve and a tubular means connected with said main gas valve and operable thereby, said tubular means surrounding the pilot valve and being provided with openings for the passage of the pilot gas and being further provided with means for progressively throttling the passage of the pilot gas when the main gas valve is moved by the thermostat beyond its completely open position.

14. A device according to claim'13 wherein the rod actuated by the thermostat comprises a thrust rod, one end of which passes through the main gas valve and actuates the pilot-flame valve, while its other end is provided with a head adapted to actuate the main gas valve.

15. A safety ignition device for gas burners comprising a thermostat heated by a pilot flame, a pilot-flame valve and a main gas valve which are opened and closed in succession by said thermostat, and additional valve means arranged c0- axially of and operatively connected to said main valve and controlling the supply of gas to the pilot flame whereby the supply of gas to the pilot flame is progressively throttled by said valve means when said main gas valve is moved beyond its completely open position.

17. A safety ignition device for gas burners comprising a thermostat heated by a pilot flame, a pilot-flame valve, a main gas valve, a control device actuated by said thermostat, said control device directly engaging and operating said valves so that, when the thermostat is heated, first the pilot flame valve and then after a predetermined lapse of time the main gas valve are opened in succession by said thermostatically actuated contrbl device, said valves being closed in reverse order when the thermostat cools down, and valve means arranged coaxially of and operatively associated with said main gas valve, said control device operat ng said valve means to control the supply of gas to the pilot flame whereby, the supply of gas to the pilot flame is progressively throttled by said valve means when said main gas valve is moved beyond its completely open position.

GEORG HEGWEIN.