US2818916A

US2818916A - Gas igniter torch

Info

Publication number: US2818916A
Application number: US476103A
Authority: US
Inventors: Cowan Frederick
Original assignee: Combustion Engineering Inc
Current assignee: Combustion Engineering Inc
Priority date: 1954-12-20
Filing date: 1954-12-20
Publication date: 1958-01-07
Anticipated expiration: 1975-01-07

Description

Jan. 7, 1958 F. COWAN (ms IGNITER TORCH 2 Sheets-Sheet 1 Filed Dec. 20, 1954 I Fig. l.

INVENTOR Frederick Cowun 52am A p/11 w ATTORNEY 2 Sheets-Sheei 2 Filed Dec. 20, 1954 lNVENTOR Frederick Cowun A! Kw ATTORNEY United GAS IGNITER TORCH Application December 20, 1954, Serial No. 476,103

15 Claims. ((-11. 158-115) This invention relates to gas. igniters. of the type employed for ignition of the main burners of a boiler or the like, and has specific relation to such an igniter having. a control means. which is semiautomatic in its operation.

In general the igniter comprises a tube or conduit means having an electrical spark. igniter positioned therewithin intermediate its ends and having a pair of inlets adjacent one of its ends for the admission of a gaseous fuel and air, respectively, with. the other. end of the igniter tube being disposed adjacent. a main burner or the like. Electro magnetically operated valves are provided to individually control the supply of gas and. air to. the igniter tube. Energization of the spark igniter and actuation of these valves is controlled through an electricalcontrol organization which includes various electrical. circuits and a manually actuatable switch associated with the circuits, with the circuits and switch being interrelated in such a manner that when the switch is moved to one of its three operating positionsthe igniter will be energized and the electro magnetically operated valve controlling the air supply will be moved to its open position. After this valve has been openeda predetermined time, electrical mechanism, which forms a part of the interrelated electrical circuits, will automatically become effective tocause this valve to close and a predetermined time thereafter to automatically cause the gas valve to open. When the gas, which will then. be supplied to the igniter tube, reaches the spark igniter combustion will be initiated in the. interface of the gas and air with this zone of combustion travelling through the tube with the gas flow until. it. reaches the end. thereof, which is positioned adjacent the main burner, and where the secondary air for the burner will continue to support combustion of the gas. After combustion. of the gas has been thus initiated the manually operaive switch is moved. to a second of its positions where theelectrical igniter is deenergized but the gas valve remains open. has been thus initiated the manually operative switch is moved to its third operating positionwhich causes the gas valve to close and the air valve to open with the inter.- related circuits being effective after a predetermined time to automatically cause the air valve to close and all the circuits to be deenergized;

It is an object of this invention to provide an improved gas igniter torch-of the typewherein the electrical spark igniter is remote from the end of'the torch with the combustion of. the gaseous fuel supplied to the igniter being initiated in the location. of the spark igniter and then transferred to the. endof the igniter and with the' operation of the igniter being semiautomatic.

It is a further object of this invention to provide a gas igniter torch of this type: which is semiautomatic in its operation and which is relatively simple and econoinical in construction and yethighly reliable in operation.

Other and further objects of the invention will'become apparent to those skilled in the art as the' description proceeds.

rates Patent With. the aforementioned objects in. view, the invention comprises an arrangement, construction and. combination of the elements of the inventive organization. in such a: manner as to attain the results desired as. hereinafter more particularly set forth in the following detailed description of an illustrative embodiment, saidembodiment being shown by the accompanying drawing wherein:

l ig. l is a horizontal sectional view through one type of burner with which the igniter may be employed and showing the manner in which the igniter may be associated with the burner.

Fig. 2 is an elevational view, somewhat diagrammatic, ofthe igniter of this invention.

Fig. 3 is a circuit diagram of the electrical controlwhich forms a part of the igniter and by which operation ofthe igniter is controlled.

Figs. 4, 5 and 6 illustrate the three operative positions of the manually operable switch forming a part of the electrical circuit.

Referring now to the drawings wherein like reference characters are used throughout to designate like elements, the invention is illustratively disclosed as applied to a well known type of main burner mounted in the corner of a furnace of a boiler and including an oil supply pipe lt) extending through wind box 12; to the tip member 1'4 located intermediate the vertically extending furnace cooling tube 16. The wind box is suppliedwith secondary combustion supporting airwhich passes'through the. vaned. nozzle member 18 with this nozzle member being mounted for adjustable movement about the axis 20 in order that the direction at. which the combustion supporting air is projected into the furnace and accordingly the zone of combustion in the furnacemay bevaried longitudinally of the furnace with this adjustment being effected through the operating mechanism 221 Also extending through wind box 12 is the igniter'tube 24" which has its tip 26 located adjacent the end of the main burner within and axially parallel of the stream of combustion supporting air and in such a position that the flame from the igniter is effective to light the burner during starting-up operation.

The combustion supporting air supplied to the main burner thus supports combustion of the gaseous fuel of the igniter attip 26 and in order to prevent the high velocity of this secondary air from extinguishing the flame of the igniter, tip 26, which includes secondary nozzle 19 concentrically disposed Within perforate fire tube 21, is provided with a radial baffle 23" at the end of. tube 21 to at least partially prevent or eliminatethe venturi or aspirator effect that would prevail because of'the axial flow of air over the tube 21'. Withoutbaffie 23 this aspirator effect would result in a substantially reduced pressure at the end of tip 26 causing'extinguish ment of the igniter.

In accordance with the present invention the igniter is lit by an electrical spark ignition means 27 which is located remote from the tip 26 and includes a live electrode 28 mounted in a suitable spark plug 30 so as to be electrically insulated from igniter tube 24 with this electrode extending well into tube 24 and adjacent to but spaced from the ground electrode 32 electrically connected to the wall of the tube.

A gaseous fuel and air are supplied to the igniter tube bymeans of supply conduits 3:4 and 36, respectively, with this supply being controlled by the normally closed electro' magnetically operated valves 38 and4ll.

Operation of these valves as well as energization and deenergization of the spark igniter are controlled through an electrical control mechanism disposed within housing 42. This electrical control is diagrammaticallyillustrated in Figs: 3 through 6 and includes a manually operable switch'44 having three operating positions; a-first wherein 25 the igniter is lit or ignited, a second wherein the igniter is continued in operation after being lit, and a third wherein the igniter is shut off or extinguished with these positions being disclosed respectively in Figs. 4, and 6.

The switch has a movable sweep contact 43 and three

stationary contacts

45, 47 and 49 and when the switch is in its ignite position contact 43 is in engagement with both of the

contacts

45 and 47 thereby completing the electrical circuit between the electrical supply lines 46 through igniter 27 by means of conductor 48 and through the solenoid of valve 46 by means of conductor 50 and contact 52 of relay 54. Also when switch 44 is in its ignite position the circuit which includes the electrical heater 56 is completed with this circuit being in series with contact 45 of the switch. Associated with this heater is the normally open thermal actuated switch 58 which is in series with the solenoids of relays 54 and 60 which are connected across power lines 46 by means of conductors 53 and 55. After heater 56 has been energized for a short time the temperature of the temperature responsive elements of switch 58 is increased sufiiciently to cause this switch to move to the closed position thereby energizing the

relays

54 and 66. Energization of relay 54 causes the pick up of the relay to move away from or open the contact 52 and move into engagement with or close the contact 62 resulting in breaking the circuit of the solenoid of valve 46 through conductor 50 and contact 45 causing the valve to close while energization of relay 60 causes the normally open contacts 64 thereof to close thereby completing the circuit of the electrical heating element 66 which includes

conductors

57 and 59. Positioned adjacent this heating element 66 is the normally open thermally operated switch 68 which is connected in series with contact 45 of switch 44 and with the solenoid of the gas valve 38. After heater 66 has been energized for a short time the temperature sensitive element of switch 68 is heated sufiiciently to cause this switch to close thereby completing the circuit through the solenoid of gas valve 38 through conductors 61 and 63 and causing this valve to open whereupon the igniter is lit since upon the gas reaching spark igniter 27 it will become ignited with the combustion taking place at the interface of the gas and air and with the zone of combustion being moved by the gas flow from the location of spark igniter 27 to the tip 26.

After the igniter is lit switch 44 is moved to its second or operate position where sweep contact 43 is moved out of engagement with contact 47 but remains in engagement with contact 45 thereby being effective to break the circuit of electrical spark igniter 2'7 and accordingly deenergize the same but otherwise leave the electrical control unaffected. By decnergizing the spark igniter the electrodes of this igniter are prevented from becoming carbonized whereupon the operating life of the electrodes are greatly increased, it being essential for this reason that the spark igniter be energized as short a time as possible.

When it is desired to extinguish the igniter, switch 44 is moved to its third or off position with sweep contact 43 moving out of engagement with contact 45 and into engagement with contact 49 thereby being effective to break the circuit to solenoid 38 of the gas valve and the circuit of electrical heater 56 causing this valve to close and the heater to be deenergized. When moved to this 0115 position switch 44 is effective to energize the solenoid of air valve 4% through the circuit which includes contact 49 of the switch, conductor 70 and contact 62 of relay 54. This energization of the solenoid of air valve 40 will cause the valve to move to the open position and the solenoid will continue to be energized so long as relay 54 remains energized. However, since energization of relay 54 is controlled by the thermally operated switch 58 and since heater 56 which etfectively controls the operation of this thermally operated switch is deenergized when the manually operable switch 44 is 4 moved from its operate to its off position the relay 54 will remain energized only the short time required for the electrical heater 56 and the temperature responsive member of switch 58 to cool sufliciently for the switch to move to its open position breaking the circuit through relay 54 and causing the relay to move away from contact 62 which in turn results in deenergization of the solenoid of air valve 40 causing the valve to close.

In the operation of the igniter of this invention when it is desired to light the igniter preparatory to initiating operation of the main burners of a boiler or the like, switch 44 is moved from its ofi to its ignite position where it is in closed relationship with both of the

contacts

45 and 47 and immediately energizes spark igniter 27, heater 56 and the solenoid of air valve 40 establishing a flow of purge air through igniter tube 24. After a short time the heater 56 causes switch 58 to move to the closed position energizing relays 60 and 54 which causes the electrical heater 66 to be energized and air valve 40 to be closed resulting in cutting oif the flow of purge air. After a further short time heater 66 causes the thermally actuated switch 68 to move to its closed position thereby energizing the solenoid of gas valve 38 causing the same to move to the open position establishing a flow of gas into tube 24. As the interface between the gas now supplied to igniter tube 24 and the air previously supplied to the tube reaches the spark igniter 27 the gas commences to burn with this zone of combustion travelling along the tube to the tip thereof where the secondary air supplied to the main burner and in the stream of which the tip of the igniter is positioned thereafter supports combustion of the gas passing through the igniter tube.

After the igniter is thus lit switch 44 is moved to its second or operate position wherein contact 47 is disengaged but contact 45 remains engaged by sweep contact 43 thereby deenergizing electrical igniter 27 but retaining gas valve 38 in the open position.

In order to insure that switch 44 will not be left in the ignite position and thus damage the electrical igniter 27 spring 51 is provided and is eifective to bias the switch from the ignite to the operate position thus requiring the operator to hold the switch in the ignite position during the period of lighting the igniter with the switch moving to operate position when the operator ceases to hold it.

When it is desired to extinguish the igniter, as may be the case after the main burners are in operation and producing a stable flame condition, manual operable switch 44 is moved to its third or oft position where sweep contact 43 is out of engagement with contact 45 and in engagement with contact 43 resulting in closing gas valve 38 and deenergizing heater 56 but opening air valve 40 through the medium of conductor 70 and contact 62 of relay 54. After a short time, however, the temperature responsive element of switch 58 will cool sufficiently to cause switch 58 to open which will deenergize relays 54 and 60 resulting in breaking the circuit to the solenoid of air valve 40 which was closed when switch 44 was moved to the oif position thereby causing the air valve to close. The electrical control is then completely deenergized and the igniter is extinguished.

Thus with the igniter of this invention by merely moving switch 44 to the ignite position the electrical igniter 27 is energized and purge air is supplied to igniter tube 24; after a predetermined time the supply of purge air is shut oft; and after. a further predetermined time a gaseous fuel is supplied to igniter tube 24. With this automatic operation proper lighting of the igniter is assured. It is important that there be a definite time delay between the shutting off of the air supply to the igniter tube and the initiating of the gas supply to this tube. This is necessary in order that there will be a sharp interface between the gas and air and there will not be a zone of substantial length where there will be a mixture of the ass-sets gas andwair. which may cause a puff or explosion. With the present invention this delay is insured and in no way can be varied by any manipuiation by the operator.

In addition to the foregoing automatic operating sequence, when manual switch 44 is moved to the closed position the air purge for purging the igniter tube of unburned gas continues fora predetermined time and then is automatically shut off. This insures that there will be sufficient air purgelto completely clear the igniter tube of any gaseous fuel and fumes, with this air purge being automatic and also not subject to any variations by any manipulations of the operator;

The time during which electrical igniter 27 is energized is. maintained at a minimum, since it is energized only during the ignition cycle of igniter operation and it is impossible to energize the same during the final air purge cycle or in any cycle of operation but the ignition cycle thus greatly prolonging the useful life ofthe electrical igniter.

Because of the specific construction of tip 26 of the igniter the very high. velocity stream of secondary air, which may be 80 feet per second, does not cause the flame to be sucked from tip 26 and thus extinguished. The radial ring baffle 23 breaks up the flow of the axially moving stream of secondary air preventing the forming of a substantially reduced pressure at the end of tip 26 and creating sufficient turbulence for eflicient combustion of the fuel at the tip of the igniter.

While the relays and thermally responsive switches have been illustratively disclosed in the circuit diagram for accomplishing the desired results the invention is not limited to the use of such apparatus but includes the use of other conventional electrical apparatus which will produce the same operative results. Moreover, a single relay may be employed in lieu of the two illustratively disclosed.

With the electrical control organization of this invention remote and simplified operation of the igniter is provided in a most simple and expeditious manner.

While I have illustrated and described a preferred embodiment of my novel organization it is to be understood that such is merely illustrative and not restrictive and that variations and modifications may be made therein without departing from the spirit and scope of the invention. I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes as fall within the purview of my invention.

What I claim is:

I. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an. electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed air and gas valve means for controlling the admission of air and gas to said condui-t, electrical means operative to control said valve means and said igniter including a manually controllable switch means operative when moved to one position to activate said electrical igniter and cause said air valve means toopen, a first electrical timer activated bysuch positioning of said switch means to cause said air valve means: to close after it has been opened a predetermined time, a. second electrical timer operative after a further predetermined time to cause said gas valve means to open, said switch means having another operative position wherein it is effective to prevent energization of the igniter and cause the gas valve means to close but cause the air valve means to open.

2. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valve means for controlling the admission of air and gas to said conduit, eleo trical means operative to control said valve means and said igniter including manually controllable switch operative when moved to one position to activate said electrical igniter and cause said air valve means to open, electrical timer mechanism activated by such positioning of said switch means to cause said air valve means to close after it has been opened a predetermined time and after a further predetermined time to cause said gas valve meanstoopen, said switch means having another position wherein it is effective to cause said gas valve means to remain open but prevent activation of said igniter, and said switch having a third position wherein it. is effective to prevent activation of the igniter and cause the gas valve means to close but cause the air valve means to open.

3. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical. igniter provided in said conduit downstream of the admission of said gas and air but remote from said otherend, individual normally closed valves for controlling the admission of air and gasto said conduit, electrical means operative to control said valves and said igniter including a manually controllable switch operative when moved to one position to cause activation of said: igniter and to cause said air valve to open, electrical timer mechanism activated by such positioning of said switch means to cause said air valve to close after it has been opened a predetermined time and after a further predetermined time to cause said gas valve to open, said switch having another operative position wherein it is effective to cause the gas valve to close and prevent activation of the igniter but cause the air valve to open, the aforementioned electrical timer mechanism activated by the positioning of said switch being operative to cause the air valve to close a predetermined time after said switch is moved from said one to said other position.

4. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valve means for controlling the admission of air and gas to said conduit, electrical means operative to control said valve means and said igniter including a manually controllable switch operative when moved to one position to activate said electrical igniter and cause said air valve means to open, electrical timer mechaism activated by such positioning of said switch means to cause said air valve means to close after it has been opened a predetermined time and after a further predetermined time to cause said gas valve means to open, said switch means having another position wherein it is eifective to cause said gas valve means toremain open but prevent activation of said igniter, and said switch having a third position wherein it is effective to cause the gas valve means to close and prevent activation of the igniter but is effective to cause opening of the air valve means, the aforementioned timer mechanism activated by the positioning of the switch means in its first mentioned position being operative to cause the air valve means to close a predetermined time after said switch is moved to said third position.

5. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valve means for controlling the admission of air and gas to said conduit, electrical means operative to regulate both of said valve means and also said igniter including a pair of parallel circuits one of which is associated with the valve means for the gas and the other with the valve means for the air, with said circuits being operative when energized to cause the normally closed valve means associated therewith to move to the open position, each of said circuits having means therein to control current flow therethrough with said means being normally conditioned to prevent current flow through said one circuit and permit current flow through said other circuit, a switch means in series with the circuits of said valve means and having a common closed position with respect thereto, electrical timing mechanism associated with said switch and operative to automatically condition the control means in the other circuit to prevent current flow therethrough a predetermined time after said switch has been moved to its said closed position and to automatically condition the control means in said one circuit to permit current flow therethrough a still further predetermined time after this positioning of said switch.

6. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valve means for controlling the admission of air and gas to said conduit, electrical means operative to regulate both of said valve means and also said igniter including a pair of parallel circuits one of which is associate-d with the valve means for the gas and the other with the valve means for the air, with said circuits being operative when energized to cause the normally closed valve means associated there- With to move to the open position, control means associated with said circuits and etfectively electrically activated to control current flow through said circuits with said means being normally conditioned to prevent current flow through said one circuit and permit current flow through said other circuit, switch means in series with the circuits of said valve means and having a common closed position with respect thereto, said control means being associated with said switch and being automatically conditioned to prevent current flow through the other circuit a predetermined time after said switch has been moved to its said closed position and being automatically conditioned to permit current flow through said one circuit a still further predetermined time after this positioning of said switch, said switch having another position where it is efiective to prevent energization of either of said circuits but permit energization of a third circuit which is associated with said air valve means and the energization of which causes said valve means to move to the open position, and means in said third circuit effective to prevent current flow there through a predetermined time after said switch is moved from said common closed position to said other position.

7. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electri cal igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valve means for controlling the admission of air and gas to said conduit, electrical means operative to regulate both of said valve means and also said igniter including a pair of parallel circuits one of which is associated with the valve means for the gas and the other with the valve means for the air, with said circuits being operative when energized to cause the normally closed valve means associated therewith to move to the open position, control means associated with each circuit and eifectively electrically actuated to control current flow therethrough with said control means being normally conditioned to prevent current flow through said other and permit current flow through said one circuit, a switch in each of said circuits and the circuit of said electrical igniter, said switch having a common closed position with respect to these circuits, said control means being associated with said switch with the control means being automatically conditioned to prevent current flow through said other circuit a predetermined time after said switch has been moved to its said closed position and the control means being automatically conditioned to permit current flow through said one circuit a still further predetermined time after this positioning of said switch, said switch having another position where it is effective to prevent energization of said electrical igniter but remains in the closed position with respect to said one and said other circuit, said switch having still another position where it is effective to prevent energization of either said one or said other circuit but permitting energization of a third circuit which is associated with said air valve means and the energization of which causes said air valve means to move to the open position, and means in said third circuit effective to prevent current flow therethrough a predetermined time after said switch is moved from either of the first two mentioned positions to the last mentioned position.

8. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted at one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valves for controlling the admission of air and gas to said conduit, electrically actuated valve operating means for etfecting operation of each of said valves, means for controlling energization and deenergization of said valve operating means and said electrical igniter comprising a switch means in series with both of said operating means and occupying a closed position with respect to the circuits thereof and the circuit of the igniter when in one of its positions, means in the circuit of the operator means of the gas valve normally occupying a current blocking position, means effective after said switch has been in said one position for a predetermined time to prevent current flow through the circuit of the air valve and a predetermined time thereafter to condition said means in the circuit of the gas valve to permit current flow therethrough, said switch means being movable to another position where it is efiective to open said circuits to said valve operating means and said igniter and complete a second circuit which includes the operating means of the air valve, means forming a part of said second circuit effective to prevent current flow therethrough after said switch has been moved from said one to said other position a predetermined time.

9. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted at one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission ofsaid gas and air but remote from said other end, indi vidual normally closed valves for controlling the admis sion of air and gas to said conduit, electrically controlled actuating means for each valve, one circuit associated with both actuating means and another circuit associated with only the actuating means for the air valve; 2. manually operable switch means effective to control said valves and said igniter and operative in one position to activate said igniter and to permit energization of the actuating means for the gas valve and energization of the actuating means for the air valve through said one circuit but preventing energization of the actuating means for the air valve through another circuit and in said other position to prevent energization of the actuating means for the gas valve and energization of the actuating means for the air valve through said one circuit but permit energization of the actuating means for the air valve through said other circuit, additional means normally preventing energization of the actuating means for the gas valve and additional means normally permitting energization of the actuating means of the air valve through said one circuit but preventing energization thereof through said other circuit, said additional means being effectively controlled by said manually operable switch and being constructed and arranged so the additional means associated with the air valve is conditioned to preasraere vent energization of the actuating means thereof through said one circuit and permit energization thereof through said other circuit a predetermined time after said switch is moved to said one position and after a further time delay the additional means associated with said gas valve is conditioned to permit energization of the actuating means thereof and said additional means associated with the air valve remains so conditioned a predetermined time after said switch is moved from said one position.

10. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closedvalves for controlling the admission of air and gas to said conduit, electrical means for actuating each of said valves, means operative to control actuation of said actuating means and accordingly said valves and energization of said igniter includ ing a first and second circuit containing the actuator of the air valve, a third circuit containing the actuator of the gas valve, a fourth circuit, a circuit breaker in each of said first three circuits effectively electrically actuated with that in the first circuit normally closing said circuit while those in the second and third normally break the circuits, means responsive to energization of said fourth circuit and effectivev after the same has been energized for a predetermined time to effect actuation of said circuit breakers causing that associated with said first circuit to break said circuit and those associated with said second and third circuits to close said circuits, said last named means being effective to retain the circuit breakers in this condition a predetermined time after deenergization of said fourth circuit, means effective to delay this actuation of the circuit breaker in the third circuit a predetermined time after actuation of that in the first circuit, and manually controllable switch means effectively disposed in each of said four circuits.

11. The organization of claim 10 wherein the means responsive to energization of the fourth circuit is normally open thermal actuated switch adapted to move to the closed position upon an increase in temperature and having an electrical resistance disposed in said fourth circuit adapted to become heated upon energization of the same and after a predetermined time effective to heat said thermal actuated switch sufficiently to cause it to move to the closed position.

12. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valves for controlling the admission of air and gas to said conduit, electrical means for actuating each of said valves, means operative to control actuation of said actuating means and accordingly said valves and energization of said igniter including a first and second circuit containing the actuator of the air valve, a third circuit containing the actuator of the gas valve, a fourth circuit, a circuit breaker in each of said first three circuits effectively electrically actuated with that in the first circuit normally closing said circuit while those in the second and third normally breaking said circuits, means responsive to energization of said fourth circuit and effective after the same has been energized for a predetermined time to effect actuation of said circuit breakers causing that associated with said first circuit to break said circuit and those associated with said second and third circuits to close said circuits, said last named means being effective to retain the circuit breakers in this condition a predetermined time after deenergization of said fourth circuit, means effective to delay this actuation of the circuit breaker in the third circuit a predetermined time after actuation of that in the first circuit, and manually controllable switch means effectively disposed in each of said four circuits, said switch means having a common actuator and being operative when in one position to close the switch means with respect to said first, third and fourth circuits and open the switch with respect to said second circuit and in another position to close the switch means with respect to said second circuit and open the switch means with respect to said first, third and fourth circuits.

13. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream ofthe admission of said gas and air but remote from said other end, individual normally closed valves for controlling the admission of'air and gas to said conduit, electrical means for actuating each of said valves, means operative to control actuation of said actuating means and accordingl=y said valves and energization of said igniter including a first and second circuit containing the actuator of the air valve, a third circuit containing the actuator of the gas valve, a fourth circuit containing said igniter, a fifth circuit, a circuit-breaker in each of said first, second and third circuits effectively electrically actuated with that in the first circuit normally occupying a closed position: with respect to said circuit while those in the second and third circuitsnnormally' occupying: an open: or circuit breaking position with respect to said circuits, means responsive to? energization of said fifth circuit and effective after the same: has been energized a predetermined time. to effect actuation of said. circuit breakers causing that associated with said first circuit to occupy an open or breaking; position withlrespect to" said circuit and those associated with said second and third circuits to occupy a closed position with respect to said circuits, said last named means being effective to retain the circuit breakers in this condition a predetermined time after deenergization of said fifth circuit, means effective to delay this actuation of the circuit breaker in the third circuit a predetermined time after actuation of that in the first circuit, and manually controllable switch means effectively disposed in each of said five circuits.

14. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical igniter provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valves for controlling the admission of air and gas to said conduit, electrical means for actuating each of said valves, means operative to control actuation of said actuating means and accordingly said valves and energization of said igniter including a first and second circuit containing the actuator of the air valve, a third circuit containing the actuator of the gas valve, a fourth circuit containing said igniter, a fifth circuit, a circuit breaker in each of said first second and third circuits effectively electrically actuated with that in the first circuit normally occupying a closed position with respect to said circuit while those in the second and third circuits normally occupying an open or circuit breaking position with respect to said circuits, means responsive to energization of said fifth circuit and effective after the same has been energized a predetermined time to effect actuation of said circuit breakers causing that associated with said first circuit to occupy an open or breaking position with respect to said circuit and those associated with said second and third circuits to occupy a closed position with respect to said circuits, said last named means being effective to retain the circuit breakers in this condition a predetermined time after the energization of said fifth circuit, means effective to delay this actuation of the circuit breaker in the third circuit a predetermined time after actuation of that in the first circuit, and manually controllable switch means, said switch means having a common actuating means and being operative when in a first position to close the switch means with respect to said first, third, fourth and fifth circuits but 0136111 means with respect to the first, third and fifth circuits and open the switch means with respect to the remaining circuits, and in a third position operative to close the switch means with respect to said second circuit and open the switch means with respect to said first, third, fourth and fifth circuits.

15. A gas igniter torch of the type described comprising a conduit into which gas and air are admitted adjacent one of its ends for passage to said other end, an electrical ignitcr provided in said conduit downstream of the admission of said gas and air but remote from said other end, individual normally closed valves for controlling the admission of air and gas to said conduit, electrical means for actuating each of said valves, means operative to control actuation of said actuating means and accordingly said valves and energization of said igniter including a first and second circuit containing the actuator of the air valve, a third circuit containing the actuator of the gas valve, a fourth circuit containing said electrical igniter, a fifth circuit, a circuit breaker in each of said first, second and third circuits effectively electrically actuated with that in the first circuit normally closing said circuit while those in the second and third circuits normally breaking said circuits, a normally open thermal actuated switch controlling actuation of said circuit breakers and effective when closed to cause the circuit breaker associated with said first circuit to break said circuit and those associated with said second and third circuits to close said circuits, an

12 electrical resistance forming a part of said fifth circuit and disposed in juxtaposition with said thermal actuated switch, said resistance being heated upon energization of said fifth circuit and after a predetermined time being effective to heat said thermal actuating switch to cause it to move to the closed position, means effective to delay the aforesaid actuation of the circuit breaker in the third circuit a predetermined time after actuation of that in the first circuit, manually controllable switch means effectively disposed in each of said five circuits with said switch means having a common actuator operative to position said switch means in any one of three positions with said switch means occupying a closed'position with respect to said first, third, fourth and fifth circuits and an open position with respect to said second circuit when in one of its positions, occupying a closed position with respect to said first, third and fifth circuits and an open position with respect to said second and fourth circuits when in a second position, and occupying a closed circuit with respect to said second position and an open position with respect to said first, third, fourth and fifth when in a third position.

References Cited in the file of this patent UNITED STATES PATENTS 2,161,248 Denison et a1 June 6, 1939 r 2,401,393 Wakefield June 4, 1946 2,591,626 Sloan Apr. 1, 1952 2,622,669 Caracristi et a1 Dec. 23, 1952 2,768,676 Deubel Oct. 30, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,818,916 January '7, 1958 Frederick Cowan It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 53, strike out "has been thus initiated. the manually operative switch is and insert instead me When it is desired to extinguish the igniter this switch is ,1 column 12, line 20, for "circuit" read position line 21, for "position" read. circuit Signed and sealed this 26th day of August 1958o (SEAL) Attest:

KARL AXLINE ROBERT C. WATSON Commissioner of Patents Attesting Ofiicer