US2164417A

US2164417A - Gas burner

Info

Publication number: US2164417A
Application number: US164611A
Authority: US
Inventors: Garnet W Mckee
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-09-20
Filing date: 1937-09-20
Publication date: 1939-07-04
Anticipated expiration: 1956-07-04

Description

vJuly 4, 1939.

cms BURNER 'Filed sept. 2o. 1937 2 sheets-sheet l Gfw. MCKEE f 2,164,417

2 Sheets-Sheet 2 G. w. `MCKEE l GAS BURNER Filed Sepp. 2o, 1957 July 4, wsal melted July 4, 193s PATE-NT OFFICE Gas comme. y Garnet w. mxe, Rockford, m. Application September 20, 1937, Serial No. 164,611

SClaiml.

`'Ihe present invention relates generally to gas burners for furnaces and other heating apparatus. More particularly the invention relates to that type of. gas burner which is known as an atmospheric burner and comprises as the. main parts thereof a burned head; a Venturi type injecting tube which is connected at its large or discharge end to the burner head and is adapted to have air ilow into its other or throated end;

a 'nozzle which is connected by a pipe to receive gas under pressure and is adapted to jet the gas' through the tube to the burner and cause it to entrain and draw into the tube from the atmosphere around the throated end of the tube a certain quantity ofv air; a valve which is connected to the gas supply pipe and is adapted to control theilow of gas to the nozzle; a thermostatically controlled motor and gear mechanism for automatically opening and closingthe gas valve in response to temperature changes in the space in which the thermostat is located; and an air valve which is associated with the throated end of the injecting tube and is controlled automatically so that -when the burner is' shut oif it is closed slightly before shift of the gas valve into its closed position in order to shut oi the flow of air into the tube prior to stoppage oi the gas from the nozzle andythus prevent the formation of a combustible mixture in the tube and resultant back-rng.

One object of the inventionA is to provide an atmospheric burner of this type which is an improvement upon, and is more emcient than, the I burner which is disclosed in and forms the subi ject matter of United States Letters Patent No.

1,937,974, granted to me. December 5, 1933.

Another object of the invention is to provide an atmospheric gas burner ,of the aforementioned type in which the valve for controlling the flow of air into the throated end of the injecting tube is oi the rotary register type and is controlled automatically by way of a solenoid in circuit with the motor of the thermostatically controlled mechanism for automatically opening and closing the gas valve.

Other objects of the invention and the various advantages and characteristics of the present gas burner will b e apparent from a consideration of the following detailed description.

The invention consists in the several novel features which Vare hereinafter set forth and are more particularly defined by claims at the conclusion hereof.

In the drawings which accompany and form atmospheric type. It is air valve, that is, the

a part oi' this specification or disclosure and in which like numerals of reference denote correspending parts ,throughout the several views:

Figure 1 is a perspective o1' a gas burner em-' bodying the invention;

Figure 2is a perspective of the thermostatically controlled motor` and gear mechanism for automatically opening and closing the gas valve; Figure 3 is a vertical longitudinal sectional view of the 'motor and gear mechanism;

Figure 4 is a vertical transverse sectional view taken on the line 4 4 of Figure 3; y

Figure 5 is a vertical longitudinal sectional view of the burner head and injecting tube illustrating in detail the design and construction of the air valve for controlling the flow of air into the throated end of the tube; and

Figure 6 is a diagrammatic view of the electrical circuit for the motor of the gas valve controlling mechanism and the solenoid for actuating or shifting the air valve.,

The burner which is shown in the drawings constitutes the preferred embodiment of the invention and is essentially a gas burner of the adapted for use in connection with a furnace or heating apparatus y vhaving a combustion chamber deilning wall w and comprises a burner head 1, a Venturi type injecting tube 8, and a nozzle l.

The burnerhead 1 is in the form of a sleeve 30 and is adapted to receive a mixture of gas and air from the injecting tube 8. It is adapted to t against the inner face of the wall w of the heating apparatus as shown in Figure l, and embodies an internal outwardly tapered annular ange I0. 'Ihe latter is adapted to increase the velocity of the fuel mixture as it emanates from the burner head and has an annular series of holes or apertures Il which extend from the inner i'ace of the ange to the outer face and 40 cause a portioni of the fuel mixture to flow` outwards in the form of an annular series of jets around the main portion of the mixture. vAn externallythreaded pipe nipple l2 serves to connect the burner head to the discharge end of the injecting tube 8. One end of this nipple ts within an internally threaded socket I3 inthe Y inlet endof the burner head and the other end of the tube `lits in an internally threaded socket il in the discharge end of the tube. 'Ihe tube yim' end of the tube and is connected at one end thereof to an annular flange I1 on the inlet end of the tube 8 by a screw thread connection I8. The other end of the mixing sleeve I6 has a cross-wall I9 with an annular series of spaced radially extending slots 20 therein and is adapted when the burner is in operation to have air drawn into it through the slots 20.

The nozzle 9 is centrally positioned in the mixing sleeve I6 and is adapted to receive gas under pressure from any suitable source of supply by way of a hollow member 2| and a pipe 22. The hollow element 2| is disposed in and formed integrally with the mixing sleeve I6 and communicates with a gas inlet branch 2S which projects radially from and is also formed integrally with the sleeve. The pipe 22 serves to supply gas to the member 2| for delivery to the nozzle 9. It is controlled by a valve 24 and includes a pipe section 25, an elbow 26, and a pipe connection 21. The valve serves to control the flow of gas through the pipe 22 to the nozzle and embodies a casing 28 and a valve member 29. The casing 28 is provided with a gas inlet 30 and an outlet 3| and has a cross-wall 32 which serves to separate the inlet from the outlet. As shown in Figure 3 the cross wall embodies a horizontally extending part 33 with a 'vertically extending aperture 34 therethrough. The valve member embodies an upstanding stem 35 and is vertically shiftable, as hereinafter described, to open and close the valve. The stem 35 extends through an opening 36 in the top portion of the valve casing 28 and is surrounded by a diaphragm 31. The latter extends between the stem and the portion of the casing which defines the opening 36 and prevents the escape of gas via said opening. The pipe section 25 extends horizontally and is connected at one end thereof to the outlet 3| of the valve casing 28. The other endof the pipe section 25 is connected to one branch or end of the elbow 26. The other branch of the elbow extends vertically and communicates with the inlet branch 23 of the mixing sleeve I6 by way of the pipe section 21. The injecting tube is supported at its throated end by the gas pipe 22 and is supported at its discharge or outlet end by the pipe nipple I2 which, as shown in Figure 1, extends through a hole 38 in the combustion chamber forming wall w of the heating apparatus with which the burner is associated. The nozzle 9 is located in the mixing sleeve I6 and faces towards the burner head 1.

' When the valve 24 is open, gas under pressure flows through the valve casing 28, the pipe section 25, the elbow 26, and the pipe section 21 to the gas inlet branch 23 of the mixing sleeve I6. From this inlet branch the gas flows upwards into the ho1low`member 2| and then is directed in jet form longitudinally through the injecting tube 8 to the burner head 1. As the gas flows from the mixing sleeve I6 into the throat I5 of the tube it entrains air from the atmosphere surrounding the sleeve. Such air ows inwards through the slots 20 in the cross-Wall I9 of the mixing sleeve and mixes with the gas as the latter passes through the injecting tube and hence forms a fuel mixture prior to passage to the burner head 1. As soon as the fuel mixture passes through the annular flange I0 and the holes or apertures |I in the flange it unites with additional air in the combustion chamber of the heating apparatus and burns. A needle valve 39 extends horizontally through the upper portion of the hollow member 2| in the mixing sleeve I6 and serves to control the jetting of gas through the nozzle 9. This needle valve embodies apoint at one end thereof which fits within the inner end of the nozzle 9. `The other end of the needle valve ls externally threaded and fits within an linternally threaded hollow stem 40 at the back portion of the hollow element 2|. The stem 40, as shown in Figure l, extends through the central portion of the cross-wall I9 of the mixing sleeve I5. The rear or threaded end of the sleeve valve embodies a kerf 4I `whereby it may be turned with a screw driver or other turning tool for adjustment purposes.

In addition to the burner head 1, the injecting tube 8, and the nozzle 9, the burner comprises a motor and gear mechanism 42 for opening and closing the gas valve 24, a thermostat 43 for controlling the gas valve automatically in response to temperature changes, a valve 44 for controll ling the flow of air into the throated end of the injecting tube 8, and a solenoid 45 for actuating' or shifting the air valve.

The mechanism 42 is mounted on and positioned above the casing 28 of the valve 24 and comprises a frame 46, an electric motor 41, and

speed reducing gearing between the motor and the stem 35 of the valve member 29. Thejrame comprises a base plate 48, a pair of upstanding sides 49 and 50, and a sheet metal housing 5|.

The base plate 48 is rectangular and embodies at the under side thereof a depending annular ange 52. The latter corresponds in shape to the portion of the valve casing which defines the opening 36 and serves to hold the marginal portion of the diaphragm 31 in clamped relation with said portion of the casing. The central portion of the base plate 48 has an aperture o r hole through which the upper end of the stem 35 projects. The sides 49 and 50 rest upon the side margins of the base plate 48 and are secured in laterally spaced relation by spacers 53. The housing 5I surrounds .the frame sides and serves as a closure or protective medium for the motor 41 and the speed reducing gearing between the motor and the stem 35. The electric motor 41 is disposed between the frame sides 49 and 50 and comprises an armature 54 and field coils 55 around the armature. The armature extends transversely of the frame and embodies a shaft 56 which is journaled in bearings on the sides 49 and 50 of the frame 46. The speed reducing gearing between the motor and the stem 35 comprises a pinion 51 on one end of the armature shaft, a gear 58 in mesh with the pinion 51 and on a transversely extending shaft 59, a pinion 60 on the shaft 59, a gear 6I in meshlwith the pinion 60 and on a. shaft 62, and a pinion 63 on the shaft 62 and in mesh with a rack 35a on the upper end of the stem 35 of the valve member 29. The shafts 59 and 62 extend transversely of the frame 46 of the motor and gear mechanism 42 and are journaled in bearings on the frame sides 49 and 50. When current is supplied to the motor 41 the armature shaft 54 operates'through the medium of the speed reducing gearing between it and the stem 35 to raise the `valve member 29 into its open position. A coil spring 64 is mounted on the shaft 62 and serves when current to the motor 41 is cut oi to drive the speed reducing gearing in the reverse direction so as to lower the valve member 29 into its closed position. This spring is connected at one end thereof to the frame side 50 and at its other end to the shaft 62 and is adapted to be wound or placed under tension when the shaft 62 is rotated by the motor 41 in order to open the valve. The electric motor 75 the speed reducing gearing 41 is supplied with current by way of a pair of line conductors 65 and 66 and is subject to c ontrol by the thermostat 43 and a linut switch 61.

The thermostat 43 is located in, or subject to the temperature of, the space to be heated by the burner and is in the form of a switch. It is associated with the line conductor 65 and comprises a bimetallic element 68 and a pair of contacts 69 and 10. The contact 69 is connected to one end of the bimetallic element 68 and is adapted in response to lowering of the temperature in the so as to disengage the contact 69 from the contact 10 and thus open the conductor ss and the motor circuiti when the thermostat is closed current is supplied to the motor 41 and the latter through the medium of opens the valve member 49 and thus causes gas to start the burner. The limit switch 61 is included in the line conductor 68 between the thermostat 43 and the motor 41 and operates to break the motor circuit when the valve member 29 is raised by the motor into its .fully opened posi tion. It is controlled by a pin 1I and comprises a pair of

contacts

12 and 13 and a exible element 14. The contact 12 is mounted on the element` l 14 and is normally held by said element in con- 50 of the frame tact or engagement with the contact 13. 4When the contacts 69 and 10 of the thermostat 43 are engagedwith one another and the

contacts

12 and 13 of the limit switch 61 are in contact current ows through the motor 41 and the latter, as h ereinbefore described, operates through the medium of speed reducing gearing of the mechanism 42 to open the valve 24. The limit switch, as shownv in Figure 2, is mounted on a panel 15 on the side 49 of the frame 46. The pin 1I is formed of any suitable insulating material and collar 16 which 15 and is xed pin 1I rotates is carried by and radiates from a is disposed adjacent to the panel to one end of the shaft 62. Said with the shaft 62 and is so arranged that when the valve member 29 of the valve 24 approaches or reachesv its fully opened position it strikes against the Ilexible element 14 and forces the latter `in suchmanner as to disengage the contact 12 from the contact 13 abcd thus open the limit switch 61. As soon as this switch is opened the circuit `for the motor is broken and the motor hence stops. In orderto hold the valve member 29 inits raised or open position after opening of the limit switch 69 and while the thermostat 43 isin its closed` position an electromagnet 11 and an armaturef18 are provided. The magnet and armatureare located between the sides 49 and 46 and arepositioned in opposed relation with the motor". The armature 'I8 is pivotally supported on a shaft 19 and is adapted to swing towards the core piece of the electromagne't when the magnet is energized and to be swung away from said core piece by a spring 88 when the magnet is deenergized. A dog`8I is connected to the distal end of the armature 18 and is adapted when the'armature is swung toward the magnet as the result of the latter being energized' to swing into engagement with thel gear 58 and lock the latter together with the other parts of the speed reducing gearing against rotation. 'I'he magnet 11 is supplied with current from 'the line conductors by way of a pair oi to flow to the nozzle 9 -spring 64 rotates into the mixing sleeve vclosing of the air valve conductors 82 and 83 and is controlled by a switch 84 on the panel 16 so that it is automatically energized when the limit switch I1 is broken. The switch 84 comprises a pair of

contacts

85 and 86 and is disposed between the exible element 16 and one end of the conductor l2. The other end of the conductor is connected to one end of the coil of the magnet. The conductor 83 leads from core piece of the magnet and brings into locked relation with`the gear 58. When the thermostat 43 opens the

contacts

69 and 18 as the result of the temperature of the space to be heated reaching the proper .point or degree the line conductor 65 is, broken and as a result the ow of currentthrough the electromagnet 11 ceases. As soon as the magnet becomes deenergized the armature 18 yswings from. the polepiece of the magnet as the result` of the action of the spring 60 and releasesthey dog 8| from the gear 58. Upon release of the dog the coil the speed reducing gearing so as to lower the valve member 29 to its closed po'- sition. During reverse rotation of the gearing the pin 1I swings away from the exible element 14 and the latter is permitted to swing back to its normal position wherein it serves to close the thek dog 8l limit switch 61 and maintains the switch 84 open. As a result of theA action ofthe electric motor 41 and the electromagnet 11 with their respective control switches (61, 84) the valve 24 is opened when the thermostat 43 closes and remains open as long as the thermostat is closed. Upon opening of the thermostat as the result of a. rise in temperature of the space to be heated, the gear 62 is released as a result of the magnet becoming deenergized and the valve` member 29 is lowered automatically into its closed position by the action of the coil spring 64. Because of the speed reducing gearing between the electricvmotor 41 and the stem 35 of the valve member 29 the valve 24 opens and closes slowly.

The valve 44 for controlling` the ow of air I6 of the injecting tube is of ther'otar-y register type and is controlled, as

towards the hereinafter described,V so thatf'it is-'ope'red when the thermostat 43 is closed and is closed slightly before the valve 24 upon opening of the thermostat. By controlling the air valve 44 so that it closes before the gas valve, air cannot ow into the mixingL sleeve I 6-and dilute the gas and air mixture in the -`injecting tube to the point where it becomes arcombustible mixture and ignites with explosivefviolence. The small amount of gas which iows into the injecting tube after 44 and the gas valve 28 so enriches the gas and airmixture that such mixture becomes non-explosive andv hence the flame at the end of the burner head 1 dies out gradually and Without an;7 back ring within the tube. The valve 44 ts against the cross-wall I9 ci the mixing sleeve I6 and has a lcentrally disposed hub 81. The latter, as shown in Figure 5, is mounted on the outer end of the hollow stem 40 and permits the valve to rotate. 'I'he portion of the valve 44 which ts against the cross-wall is provided with an annular series nf lim-muv .coil is suitably mounted between spaced slots 88. These slots are adapted in response to rotation of the valve to be broughtI into and out of registry with the slots 28 of the cross-wall. When the valve 44 is rotated so that the slots 88 thereof are in registry with the slots 20 of the cross-wall the valve is in its open position and air is permitted to flow into the mixing sleeve I6 for mixture with the gas. When the valve is rotated so as to bring the slots 88 thereof out of registry with the slots 28 the valve becomes closed and precludes inflow of air into the mixing sleeve. n

The solenoid 45 constitutes the actuating medium for the air valve 44 and comprises a coil 89. The latter is' located a small distance outwards and beneath the mixing sleeve I6 and is mounted\4 on a base plate 90 which is fixedly secured by way of a screw 9I to a laterally extending lug 92 on the central portion of the elbow 26. The inner and outer concentrically arranged walls and has an arma- .ture 93 associated therewith, This armature is mounted for vertical sliding movement in the coil 89 of the solenoid and is connected at its upper .end by a link 94 to a stud 95 on the register type air valve 44. The stud is fixed to and projects outwardly from the valve 44 and constitutes a crank. The link 94 extends between and is pivotally connected to the outer end of the crank forming stud 95 and the upper end of the armature 93. The armature is adapted when the solenoid is energized to slide upwards and operates through the medium of the link 94 and the `stud 95 to rotate the valve 44 into its open position. When the solenoid is deenergized the armature is adapted to slide downwards in re spouse to the action of gravity and effects closing of the air valve. The coil 88 of the solenoid is adapted to be energized upon closing of the thermostat 43 and is connected to receive current from the line conductors 65 and 66 by a pair of

conductors

96 and 91. The conductor 96 is connected to one end of the coil 89 of the solenoid and is attached at its other end to the line conductor 65 at a point between thecontact 10 of the thermostat 43 and the flexible element 14. of Ythe limit switch 61. The other conductor, that is the conductor 91, extends between and is connected to the line conductor 66 and the other end ofthe coil 89. When the thermostat 43 isclosed for burner operating purposes, current flows through the conductor 96. the coil 89, the conductor 91, and the line conductor 66 and hence the solenoid becomes energized and effects opening of the air valve 44 through the medium of the armature 9 3, the link 94, and' the stud 95. When the thermostat 43 opens, the circuit through the solenoid is broken and the solenoid becomes deenergized with the result that the armature 93 slides downward in response to the action of gravity as hereinbefore pointed out. and effects closing of the valve 44. By reason of the fact that the armature 93 slides downwards in response to the action of gravity as soon as the solenoid 45 becomesdeenergized there is a substantially instantaneous closing of the air valve 44 upon opening of the thermostat 43. Since upon opening of the thermostat there is a substantially instantaneous closing of the air valve and a slow closing of the gas valve, the burner is not likely to back-fire due to an over supply of air in the injecting tube.

Assuming that there is a pilot light or other starting means at the inner end of the burner head 1, the operation ofthe burner is as follows:

Y soon as the valve When the space to be heated is at the proper temperature and the thermostat 43 is in its open position the line conductor 65 is thus broken against the passage of current therethrough.

When the temperature of the space drops so that through the motor 41 of the gas valve controlling mechanism 42: thermostat 43; line conductor 65; flexible element 14;

contacts

12 and 13 of limit switch 61; motor 41; and line conductor 66. As soon as this circuit is completed the electric motor 41 operates to drive the speed reducing gearing between it and the stem 35 of the valve member 29 and effects opening of the valve. As member 29 approaches or reaches its fully opened position the pin 1I on the collar 15 swings into engagement with the flexible element 14 and breaks the aforementioned lcircuit and establishes the following circuit through the electromagnet 11: thermostat 43; line conductor 65; flexible element 14;

contacts

85 and 86 of switch 84; electromagnet 11; conductor 83; and line conductor 66. Upon completion of this circuit the armature 18 is swung towards the core piece of the magnet 11 and brings the dog 8l into locked relation with th gear 58 so as to hold the valve member against closing as a result of the action of the coil spring 64. As long as the thermostat 43 remains closed the gas valve 24 and the air valve 44 are held in their open position. As soon as the gas valve is opened gas flows through the nozzle 9 and passes in jet form through the tube I5. As the gas flows through the tube in jet form it entrains air from the atmosphere surrounding the mixing sleeve I6 and unites with the entrained air to form a fuel mixture which burns as it passes from the burner head 1. By reason of the fact that when the thermostat closes the air valve opens instantaneously whereas the gas valve 24, opens slowly the valve 44 is in its open position when the gas passing through the pipe 22 reaches the nozzle 9. When the thermostat opens as a result of the space to be heated reaching its proper or predetermined temperature the circuit through the solenoid and the circuit through the electro magnet both become broken. As soon as the flow of current through the solenoid ceases the valve 44 is swung into its closed position, as hereinbefore pointed out, and cuts off any additional inflow of a-ir into the mixing sleeve I6`. As soon as the circuit through the electromagnet 11 is broken the armature 18 swings away from the core piece of the magnet 11 as the result of the action of the spring and causes the dog 8| to move out of engagement with the gear 58. Upon release of the dog the spring 64 operates to close the valve member 29 and thus effects stoppage of the flow of gas through the pipe 22 to the nozzle 9. As soon as the flow of gas stops the action of the burner ceases.

The herein described gas burner consists oi.'

that Vbacklring is eiectivelyprevented as' the result of instantaneous closing of the air valve 4Q and gradual closing of the gas valve 2l.

Whereas the burner has been described as comprising but.a single injecting tubel 8 it is to be understood that a battery or series of injecting tubes may be employed with individual solenoid controlled air valves and'but a sin- 'prising in combination an injecting tube having a burner head at one end thereof and adapted to A have air flow into form through the its other end, a nozzle connected to receive gas under pressure andv arranged to direct thegas so that it flows in Jet tube to the burner head and entrains air into said other end of the tube for mixture therewith, a valve for controlling the supply of gas to the nozzle, a valve for Vcontrolling the flow of air into said other end oi' the tube, a switch controlled source of electric current, mechanism, including a source supplied electric motor and adapted upon closing of the switch" slowly to open the gas valve and upon opening of such switch slowly to close said gas valve, and electric means independent of said mechanism connected to receive current from said source and adapted upon closing of the switch substantially instantaneously to open the air valve and upon opening of said switch substantially instantaneously to close the air valve.

2. An atmospheric burner of the character described comprising in combination a Venturi type injecting tube having a burner head at its large end and adapted to have air flow into its throated end, a nozzle connected to receive gas under pressure and arranged to direct the gas so that y it flows in jet form through the tube of the burner head and entrains vair into the throated end of the tube for mixture therewith, a valve for controlhng the supply of gas to the nozzle, a valve for controlling the flow of air into the throated end of the tube, a switch controlled source of electric current, mechanism for controlling the gas valve including an electric motor connected to said source and speedlreducing gearing between the motor and the gas valve, and adapted upon closing of the switch slowly to open the gas valve and upon opening of the switch slowly to close the valve, and an electncal device independent of vsaid mechanism,

connected to receive current from said source, and adapted upon closing of the switch substantially instantaneously to open the air valve and upon opening of said switch substantially instantaneously to close the air valve.

3. A burner of the character described corn-` prising in combination an injecting tube having a burner head at one end thereof and adapted to have air flow into its other end, a nozzle connected to receive gas -under pressure and` arranged to direct the gas so that it flows in jet form through the tube to the burner head and entrains air into said other end of the tube for mixture therewith, a valve for controlling positions slowly to open the the supply 01,- gas to thenozzle, a valve i'or con.- trolling the flow oi' air into said other `,end of the tube, a switch controlled source oi' electric current, mechanism for controlling the gas valve including a source supplied electric motor and adapted upon shift of the switch into one of its shift ofthe switch into its other position slowly to close said gas valve, and solenoidin the same circut as the electric motor, and adapted upon closing of the switch sub- 4 stantia'lly instantaneously to Vopen the air valve and upon opening of the switch substantially instantaneously to close the air valve.

4. An atmospheric burner oi the character described comprising in combination a Venturi type injecting tube having a burner head at its large end and adapted to have air ow into its throated end, a nozzle connected to receive gas under source of current supply, gear-type mechanism for shifting the gas valve including an electric motor connected to said closing of the switch slowly to open said gas valve,

Vand also including spring means adapted upon slowly to close the gas solenoid deenergized and substantially instantaneously to close said air valve.

5. A burner of the character described comprising in combination an injecting tube having a. burner head at one end thereof and 4adapted ing the gas valve, and automatic means including a solenoid in the same 'circuit as the motor of said mechanism' and adapted the mechanism to open the gas valve substantially instantaneously to open upon starting of the mechanism to closethe gas valve substantially instaneously to close said air valve.

6. A burner of the character described comprising in combination an injecting tube having a burner head at one end thereof and adapted to have air flow into its other end, a nozzle connected said other end of the tube for mixture therewith, a valve for controlling the supply of lgas to the nozzle, a valve for controlling the iiow of air into said other end of the tube, a thermostatically controlled mechanism for slowly opening the gas valve when the temperature of the space heated by the burner drops to a predetermined point and for slowly opening the gas valve when the temperature of said space rises to a predetermined gas valve and upon` means including av source and adapted upon l point, and automatic electric means independent of said mechanism adapted substantially instantaneously to open the air valve when the mechanism starts to open the gas valve and substantially instantaneously to close said air valve when the mechanism starts to close said gas valve.

7. An atmospheric burner o! the character described comprising in combination a Venturi type injecting tube large end and adapted to have air flow into its throated end, a nozzle connected to receive gas under pressure and arranged to direct the gas so that it flows in jet form through the tube to the burner head and entrains air into the throated end ot the tube for mixture therewith, a valve for controlling the supply of gas to the nozzle, a-valve for controlling the flow of air into the throated end of the tube, power mechanism for slowly opening and closing the gas valve, means for controlling the air valve including a solenoid and adapted when the solenoid is energized substantially instantaneously to open the air valve and when said solenoid is deenergized substantially instantaneously to open the air valve, and current means for the solenoid controlled so that the solenoid is energized as soon as the mechanism starts to open the gas valve and is dehaving a burner head at itsl 'to the burner head Aautism' energized as soon as the mechanism starts to close said gas valve.

8. A burner of the character described comprising in combination a Venturi type injecting tube and provided with a burner head at its large end and having a cross-wall at its throated end with slots therein for permitting air to flow into said throated end, a nozzle connected to receive gas under pressure and arranged'to direct the gas so that it ows in iet form through the tube and entrains air into the throated end o! the tube via certain slots -for mixture therewith, a valve for controlling the supply of gas to the nozzle, a rotary register type valve iltting against said cross-wall and adapted to control the iiow of air into the throated end of the tube, mechanism for slowly opening and closing the gas valve, and automatic means including a solenoid and an armature between the solenoid and register type valve for substantially instantaneously shifting said last mentioned valve into its open position as soon as the mechanism starts to open the gas valve and for substantially instantaneously shifting said register type valve into its closed position as soon as said mechanism starts to close said gas valve.

GARNET W. MCKEE.