US2140708A

US2140708A - Fluid fuel burner ignition control

Info

Publication number: US2140708A
Application number: US136975A
Authority: US
Inventors: Ira E Mccabe
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-04-15
Filing date: 1937-04-15
Publication date: 1938-12-20
Anticipated expiration: 1955-12-20

Description

Dec. 20, 1938. E. M CABE 40,

FLUID FUEL BURNER IGNITION CONTROL Filed April 15, 1957 4 Sheets-Sheet l I NVEN TOR IRA E. M 6 C4 85 .--1 T'I'ORNEV.

E i .-.IS BY 2%, .1938 a. 5. M QAEE 291499708 FLUID FUEL BURNER IGNITION CONTROL Filed April 15, 1937 4 Sheets-Sheet 2 INVENTOR. /RA 5 M CABE A TTORNEY.

Dec. 20, 1938. v I. E. M CABE FLUID FUEL BURNER IGNITION CONTROL Filed April 15, 1937 4 Sheets-Sheet 5 INVENTOR. IRA 6- 44 CASE A TTORNE Y.

Dec. 20, 1938. E. McCABE 2,140,708

FLUID FUEL BURNER IGNITION CONTROL Filed April 15, 1937 4 Sheets-Sheet 4 INVENTOR. ma E. M c451:

A TTORNE Y.

Patented Dec. 20, 1938 UNITED STATES PATENT OFFICE 2,140,108 FLUID roar. BURNER rem'non oomon Ira E. McCabe, Ohicaxo, m. Application April,15, 1937, Serlal No. 136,975

32 Claims. (o Isa-2s) This invention relates to improvements in electrically operated and controlled fluid fuel burning devices and more particularly to a device of this character including electrical ignition means with an improved mechanism for discontinuing the ignition means after operation of the burner mechanism has been initiated and the pressure of the fluid fuel has reached a predetermined pressure.

This invention is a further development of the means for discontinuing the operation of the ignition means when the pressure of the fluid fuel has reached a predetermined degree as disclosed in the Moje and McCabe Patent No. 1,642,937 of September 20, 1927.

It is an object of thisinvention to partially operate the ignition-discontinuing means by the pressure of the fluid fuel and employ the passage of an electric current for a predetermined time thereafter to complete the operation and discontinue the ignition means.

With these and other objects in, view, refershoe is made to the-accompanying sheets of drawings which illustrate preferred forms of this invention, with the understanding that detail changes may be made in the same without departing from the scope of the invention.

In these drawlngsz- Figure 1 is a view in front elevation of one form of this invention;

Figure 2 is an enlarged detail view in section taken on the line 2-2 of Figure 1 looking in the direction of the arrows, with parts shown in front elevation;

Figures 3, 4 and 5, respectively, are diagrammatic views illustrating the respective positions of the device shown in Figure 1 when the burner is idle, after the operation of the burner has been initiated and the pressure of the fluid fuel has reached a predetermined degree to partially operate the ignition-discontinuing means and when the continued passage of the current through the ignition circuit has resulted in the discontinuance of the ignition circuit; 1

Figure 6 is a schematic diagram illustratingthe application of. this control to an oil burner of commercial form applied to a commercial domestic heating furnace, showing the wiring to the various controls in diagram;

Figure 7 is a view in central vertical section of a fluid fuel regulating valve to which ha's been applied another form of this invention;

Figures 8, 9 and 10 are fragmentary detail views illustrating in central vertical section with parts shown in front elevation of the positions assumed byvthe operating parts shown in Figure 7 when the oil burner is idle with the valve closed and ignition switch closed, when the valve is opened, and when the passage of the current through the ignition circuit has resulted in the 5 opening of the ignition circuit, respectively;

Figure 11 is a detail view, partly-in front elevation and partly in section, of another form of this invention;

Figure 12 is a detail view in end elevation of Figure 11 with parts removed; and

Figures 13, 14 and 15 are fragmentary detail views partly in front elevation and partly in section illustrating the positions assumed by the operating parts when the operation of the burner mechanism is initiated, when the pressure of the fluid fuel has reached a predetermined degree, and when the continued passage of the current through the ignition circuit has resulted in the discontinuance of the ignition circuit. 20

The embodiment of this invention illustrated in Figures 1 to 6, inclusive, includes a construction similar to that disclosed in said Moje and McCabe Patent 1,642,937 of September 20, 1927, and which operates in part in the same manner as disclosed in said patent. The operating parts are mounted upon the back of a cylindrical casing l and include a Bourdon tube 2 closed at one end and connected at the other end through the nipple 3 to the pipe feeding the fluid fuel from the pump of the burner mechanism, whereby increase in pressure of the fluid will cause the Bourdon tube to straighten out, imparting a movement to the closed end thereof, and upon reduction in pressure cause to Bourdon tube to contract and impart a reverse movement to the closed end thereof.

The circuit to the electrically operated ignition device passes through the mercury tube switch 4, preferably of the type disclosed in this applicant's prior Patent No. 1,757,436 of May. 6, 1930. This switch 4 may be termed the ignition switch and is opened and closed by a snap mechanism actuated by movement of the Bourdon tube 2 in the manner disclosed in this applicant's prior Patent No.-1,734,016 of October 2 9, 1929.

The snap action mechanism includes a base plate 6 mounted upon the back of the casing I and a top plate 5a, suitably held in spaced relationship from the base plate 5. Upon and between these "plates there is mounted the movement parts which operate the mercury switch 4 to open and closed position. The upper central portion of these plates pivotally supports a switch operating member 6 having two incline surfaces I 1 and 8 meeting at an apex 9, and a right-angular clip-supporting extension II for supporting a mercury switch 4. A switch operating plate I l is pivotally mounted below and to one side of the pivot of the switch-operating member 8. The pivoted switch-operating plate ll pivotally mounts one end of a switch-actuating link I2 which mounts upon its free end a roller ll adapted to.

travel over the

incline surfaces

1 and 8 of the switch-operating member 8. The roller II of the switch-operating link i2 is caused to maintain contact with one or the other of the said incline surfaces by a spring 14. The movement of the closed end of the Bourdon tube is transmitted to the switch-operating plate ll through the adjustable link 15 pivotally connected to an operating lever 16 pivoted at one end to the base plate and having a pivotal connection at its other end to an actuating link ll, one end of which is pivotally and adjustably connected to the switch-operating plate ii. The above snap action mechanism so far described is similar to that disclosed in said Patents Nos. 1,642,937 and 1,734,016, with the exception of the adjustable feature of the link l5 which is utilized in this invention to vary the relationship of the movement and Bourdon tube, by shortening or lengthening the bar, to establish the point where actuation will be accomplished, in preference to the method disclosed in Patent No. 1,734,016.

This invention contemplates connecting the operating lever i6 to the actuating link i! by a stud l8 carried upon the free end of the operating lever i6 and passing through a slot I! formed in the actuating link IT. The actuating link I! mounts a thermal actuating element,

of bi-metallic metal responsive totemperature changes, with one end secured to an extension 2i of the stud it upon the upper side of the actuating link I! and the other end secured to a stud 22 carried upon the free end of the operating link 11. It is preferableto form this thermal member 20 to embrace a spool 23 of insulating material about which is wrapped a portion of the resistance wire 24 which is connected in the ignition circuit by

wires

25 and 28, in series with switch 4. The normal cold position of the thermal member 2|! is such that the part I8 is drawn against the end of the slot I! most adjacent the stud 22. When the end of the outward movement of the Bourdon tube 2 has completed the movement transmitted through the link II to the lever is to position the roller II adjacent the apex 9 of the switch-operating member I, the expansion of the thermal member 20 caused by the passage of the current to the ignition circuit will impart an additional movement to the actuating link il in the same direction to bring the other end of the slot I 9 against the stud i8 and thereby carry the roller l3 over the apex 9. By means of the adjustable feature on link ii the device may be adjusted so that when the pressure of the fluid fuel to the burner reaches its normal operating pressure, the roller l1 will be adjacent the apex 8 and by so constructing the heating coil 24, the thermal element will cause the operation of the switch a predetermined time thereafter.

As shown diagrammatically in Figure 3, the ignition switch 4 is in its closed position and the roller i 3 is at the end of its travel upon the incline surface I of the switch-operating member 6, which is the position normally assumed when the burner is idle, and the stud I8 is at the end of its movement most adjacent the stud 22.

Figure 4 illustrates the position assumed by the parts when the fluid fuel has reached its normal operating pressure and has expanded the Bourdon tube 2 to cause the roller It to assume a position upon the incline surface 1 adjacent the apex 9 of the switch-operating member I with the stud l8 still at the end of its travel most adjacent the stud 22. Figure 5 illustrates the positionrassumed by the parts after the heating element 24 has expanded the thermal element 20 to extend the link H to cause the end of the slot I! to bring its end most distant from the stud 22 into engagement with the stud l8 and thereby cause the roller 13 to travel over the apex 9 and ride down upon the incline surface 8 of the switch-operating member 6 to throw the mercury switch 4 to its open position to break the ignition circuit.

In the disclosure of this invention just described the relationship between the Bourdon tube and thermal element is such that the greater part of the movement imparted to the actuator for operating the switch-tilting mechanism is obtained from the Bourdon tube, leaving the thermal element to provide but little movement in order to complete the switch-tilting process.

, It therefore follows that by proper arrangement I of the switch mechanism for tilting the switch the cooling of the thermal member can be rendered insufllcient to return the switch to closed position and on the other hand the arrangement can also provide for reclosing the switch upon a drop in pressure above that point where fuel is cut off at the burner nozzle, regardless of whether the thermal member is in a heated or to the fuel pressure being delivered at the burner nozzle and the cut-oi! completed by a timed thermal actuator and further provides for the restoration of the ignition circuit prior to fuel cut-off at the burner nozzle upon flame extinguishment.

The diagram shown in Figure 6 illustrates an application of this improved ignition control to a domestic heating system in which an oil burner O of commercial design is shown applied to a domestic heating furnace F having a stack S leading to the chimney. The wires L and L from the source of commercial electricity pass through a hand switch H, and the incoming current of line L passes through a boiler control B of commercial construction to a stack control SC of commercial construction responsive to the stack temperature, and from thence by wires LL and LL to the burner motor M. From wire LL 9. wire 25 branches of! to the ignition switch 4 and heating element 24 of the ignition control and fromthence by wire 26 to the ignition transeformer I and thence by wire 26a to the return line LL which in turn is connected to line L within the stack control SC. .A room thermostat -T of commercial construction is connected to the mechanism of the stack control SC which responds to a call for heat in the building to initiate the operation of the oil burner. The nipple 3 of the Bourdon tube 2 is connected to the casing 2! of a regulating valve through which the fuel passes to the burner mechanism from the fuel pump 29 which is connected by the pipe 29 to a source of fuel supply, and it is preferable to provide a pressure gauge between the nipple 3 and casing 21 to indicate the pressure of the fluid fuel before it enters the burner mechanism.

The oil burner illustrated diagrammatically in Figure 6 may be fed from a tank of fluid fuel located in the basement and so arranged that the fuel will flow by ravity from the tank to the burner mechanism; or, the fuel may be stored in a tank at a distance from the oil burner and at a lower level requiring a pump to pump the fuel from the tank to the oil burning mechanism as by the pump 23 of .Figure 6. Where the fuel is to be delivered in an atomized condition it is customary to employ a fluid pressure pump as a part of the oil burning mechanism, and,- in many instances, the oil burning mechanism is suppliedwith a regulating valve as at 21 for insuring a constant flow of fuel from the pump to the oil burning mechanism.

Figures '7 to 10, inclusive, illustrate the application of this invention in which the switch in the ignition circuit is partially actuated by the movement of the oil-regulating valve usually interposed between the pump and the burner mechanism.

Figure "7 depicts a commercial type of regulating valve in which the side of the casing 3i opposite the inlet 32 is enlarged to form a chamber 33. As is customary in valves of this type, the outlet port 34 is controlled by a needle valve 35 normally held in closed position by a reciprocating plunger 36 mounted in line therewith and held thereag-ainst by a coiled spring 31, the tension of which is adjusted by the adjustable abutment 38. When the pressure of the incoming oil through the inlet 32 is sufficient to overcome the resistance of the spring 31, the plunger is forced upwardly allowing the spring 39 to act upon the needle valve 36 to open the port 34, as shown in Figure 9. The commercial types of valves of this character are usually providedwith a by-pass so that when the pressure of the incoming oil becomes greater than the amount at which the valve is set it causes the plunger 36 to continue its upward movement to uncover a port 40 in the plunger 36 whereby the excess pressure is relieved through the by-pass outlet 4| and the excess oil returned to the storage tank.

In applying this invention to a regulating valve, it is preferable to employ a mercury tube switch 42 of the type disclosed in the allowed application of Karl Hunciker, Serial No. 865,628, filed April 12, 1933, which became Patent No.

2,085,316 on June 29, 1937; in which the tubular container of-the switch 42 is normally mounted with its axis in a vertical plane. As seen from Figures '7, 8, 9, and 10, the lead-in

wires

43 and 44 enter the upper end of the container 42 and are connectedto the electrodes therein,- one of which, 46, is stationary and terminates in a pool of mercury 46 in the lower end of the container 42. The other electrode 41 is movable into and out of contact with the pool of mercury 46 and includes a resilient coil 43 which will normally maintain the electrode 41 out of contact with the mercury pool 46, as shown in Figure 10. The movable electrode 41 also includes intermediate its length an armature 49 of magnetic metal which will respond to an exterior magnetic force when brought within the field thereof to close the circuit to the switch by causing the electrode 41 to engage the mercury pool 46.

As shown in Figure 7, a switch of this type is mounted exteriorly of the wall 3! of the chamber 33 of the regulating valve. A permanent magnet 60 is adjustably mounted within the chamber 33 upon a bracket 6| pivotally mounted upon a stud 62 secured to the side walls of the chamber 33. The bracket 6i is provided with a finger 63 extending from the pivotal point 62 on the side opposite the magnet 60. The end of the finger 63 is engaged by the under side of the reciprocating plunger 36 of the regulating valve. The magnet 60 is adiustably mounted upon the bracket 6| and is so arranged that when the regulating valve is closed and the plunger 36 is at the end of its downward movement it will engage the flnger 63 to cause the magnet to approach in close proximity to the side wall 31 of the chamber 33. The switch 42 is positioned on the opposite side of the wall 31 with its armature 49 in line with the magnet 60 so that when the -magnet is in the position shown in Figures 7 and 8, the magnetic field of the magnet will act upon the armature 49 to cause the electrode 41 to close the circuit through the switch. Upon initiation of the operation of the burner mechanism the fuel pump will deliver fuel through the regulating valve causing the plunger 36 to travel upwardly. A spring 64 is carried by the bracket H to engage the side wall 3i of the chamber 33 and cause the finger 63 to follow the upward movement of the plunger 36 and thereby rotate the magnet bracket 6l, moving the magnet 60 away from the armature 49 as shown in Figure 9. It is preferable to provide a stationary abutment 66 in the valve casing within the chamber 33 which will be engaged by the bracket 6! to limit the rotation of the magnet 60. If desired, the bracket 61 may be providedwith an adjustable stop to be engaged by the abutment 66. The movement of the magnet away from the armature 49 when in the closed circuit position is adjusted so that when the abutment 66 is engaged the armature 49 will be within the outer limits of the magnetic field suiilciently to maintain the circuit closed in the switch 42.

In order to open the ignition circuit the mercury tube switch 42 is adapted to be moved away from the influence of the magnet as shown in Figure 9 to the position shown in Figure 10, whereby the circuit is broken through the switch. The switch is carried by a switch carrier 66 having a. depending portion for embracing and supporting the switch and adapted to rotate about a pivot 66a supported by brackets mounted upon the base 69 secured to the outer wall 3| of the casing 33. The switch carrier normally holds the switch tube 42 with its axis in a vertical .plane, and the side of the switch adjacent the armature 49 against the wall opposite the magnet 69 when the regulating valve is normally' closed. Adjacent the switch carrier, an actuator therefor is located consisting of a thermal member 61 of bi-metallic metal. The thermal actuator is secured at one endto a stud 66 mounted on the plate 69 with its free end adapted to engage an adjustable pin 62 carried upon the switch carrier 66. The intermediate portion of the thermal member 61 embraces aspool 60, similar in construction to the spool 23 shown in Figure 2, about which a-section of resistance wire is coiled, one end of which is connected to the ignition'circuit by lead 6| and the other end of which is connected by lead 44 to the electrode 41 of the switch 42. When the circuit to the burner motor is established, the operation of. the oil pump will cause the magnet 50 to move away from the armature 49 until it strikes the abutment Bl, as

.shown in Figure 9, and the continued passage of 10, and the circuit through the ignition device,

will be broken. It is preferable to provide the adjustable pin 62 in order to predetermine the length of the ignition period following the establishment of the ignition circuit. When the ignition circuit is broken by action of the thermal actuator 51 the thermal element will cool andreturn the mercury switch, in open circuit position, to the position shown in Figure 9, but so long as the burner continues to operate and the fuel pressure is maintained the power of the magnet will not be suflicient from its removed position to attract the armature 49. With the stopping of the burner and resulting drop in pressure the plunger 36 descends to advance the magnetic field of the magnet to embrace the armature 49 and restore the switch circuit as shown in Figure 7.

The disclosure of this invention represented by Figures '7 to 10, inclusive, incorporates the same method of ignition control as that shown by Figures 1 to 6, inclusive, only in modified form.

In this last-discussed form the power of the magnet is such that it will attract the magnetic switch armature to close the switch circuit, upon an abnormal fuel pressure drop, prior to the cutofl of fuel at the burner nozzle whether the switch is in the position it normally assumes upon burner starting, or in the removed position in which it is sometimes placed bythe thermal actuator. It is further preferable in normal operation that the movement of the magnet away from the switch be such as to render it ineffective to close the switch when, upon the opening oiv the switch by the thermal actuator, the switch is returned to its normal starting position, upon cooling of the actuator.

Figures 11 to 15, inclusive, illustrate another I form of this invention controlled by the pressure the thermally-operated of fluid delivered to the burner nozzle by the fuel burning mechanism in which the ignition switch 42 is normally open and requiresan initial pressure to be created by the operation of the burner mechanism after the establishment of the motor circuit to close the ignition circuit, prior to the establishment of delivered to the burner nozzle, and thereafter when or before the fluid pressure reaches the normal operating pressure the device will move; member into operative position and a predetermined time thereafter will allow the thermal mechanism to break the igni tion circuit.

In the course of burner operation the fuel Dump may lose its prime, or air or water may be present in the fuel'line whereupon a delay will occur in establishing. the normal fuel operating pressures, whereby if the thermal member is energized at the initiation of the burner operation it may cut ofl ignition prematurely after normal operating pressures have been attained.

In this third form an additional modification is disclosed which provides for the measurement the pressure at which. fuel is of the ignition period from the point at which fuel pressure suitable for normal burner operation is established, insuring a full period of ignition in which to establish normal burner operation.

Another advantage offered by this form is the separation of the ignition circuit, if desired, from all other circuits, made possible by the fact that the ignition circuit is open when the burner is idle, eliminating the need of control of ignition by any of the other burner control switches. thus reducing the total load carried by some of the switches.

As shown in Fig. 11, the mercury switch tube 42 is of the same type as thatillustrated in Figure 7. The device is mounted on the back of a casing not shown, with the switch 4! in the position shown. The device includes an expansible and contractible capsule 03 mounted upon the bottom 84 of the casing. The interior of the capsule is connected by the nipple II to the pipe convey-- ing the fuel under pressure to the fuel burning mechanism. The back 80 of the casing mounts spaced-apart plates 01 and I! which support between them a pivotal stud it upon which an arm 10 is mounted with one end mounting, the magnet 50. An inverted U-shaped bracket II having slots 12 on its opposite sides to allow the bracket to reciprocate between the plates 1 "and II and over the stud I9 is provided with a depending central post 13 secured to the upper central portion of the capsule I so that the bracket II will move upwardly as the capsule expands and downwardIy as the capsule contracts.

The bracket 'II is provided with an adjustable abutment stud 14 on the side of the slot I2- adiacent the magnet 50 to engage the arm 1|, upon a predetermined decrease in pressure, and move the magnet away from the switch 42 to open the circuit. 0n the opposite side of the slot the bracket 1| isprovided with a leaf spring ll bent back upon itself within the bracket and normally tending to urge the magnet toward the tube as the pressure increases and the force exerted through the stud H is relieved. The arm II and magnet 50 are such that upon closing the circuit in switch 42 the magnetic force of the magnet is sumcient to maintain the circuit closed without the aid of the spring 1!. The members I! and 18 are so adjusted that when the fuel burner mechanism is idle and the capsule l3 contracted with the bracket 'llv at the lowest end of its travel, the ad- Justable abutment 14 will contact the upper portion of the pivoted arm II and rotate it about its pivot against the tension of the spring 1! to withdraw the magnet and its magnetic held from the armature 0 of the switch 42, as 'shownin Figure 11, whereby the'circuit through the switch 42 is opened. Upon the'establishment of operation ofthefuelburningmechanismthecapsulellwill changing the relation of the positions of the 'rnagnet II and switch 4 2. r

In carrying out this invention a thermal mem= ber ll of bi-metallic metal is secured at one end to the post II preferably adjacent the under side of the bracket 1|. The thermal member ll is bent bsckuponitselfto embrace aspool 8|, with its free end 82 extending upon the other side of the post It, terminating below the arm II.- and opposite the end 11 01 the spring 15, as shown in Figures 11 to 15, inclusive. The spool 8| mounts a heating element of resistance wire similar to the spool 23 of Figure 1. One end of the resistance wire of the heating element is connected by lead 44 in series with the switch 42. The switch 42 is connected by lead 43 to one line of the ignition circuit from the source of current while the other end of the resistance wire is connected by lead 6| to an ignition transformer interposed in the return line to the source of current. The free end 82 of the thermal member 80 is provided with an adjustable abutment 83. To permit actuation of the arm 10 by the thermal member 80 as well as to provide a positive action in breaking the switch circuit an adjusting member 16 mounted upon the bracket H passes through an aperture 18 in the leaf of the spring 15 and is provided with an enlarged head on the underside thereof whereby the spring may be flexed, after the ignition switch has been closed, to remove the end 11 from contact with the arm 10.

A predeterminedtime after the ignition circuit has been closed through the switch 42 by the expansion of capsule 63 and after the bracket 13 has assumed the position shown in Figure 14, the continued passage of the current of the motor circuit through the heating element on the spool 8i will cause the free end 83 of the thermal element to move upwardly and contact the underside of the arm 10, and then cause the rotation thereof about the pivot 69 until the magnetic force of the magnet upon the armature is broken whereupon the magnet will fall away until stopped by the engagement of the far end of the arm with the free end 11 of the spring I5, as shown in Figure 15.

When the fuelburning mechanism again becomes idle, the capsule 63 will contract, causing the bracket "Ii to move downwardly, whereupon the device assumes the position shown in Figure 11 with the ignition switch open.

What I claim is:

1. In an electrically operated and controlled fluid pressure burner mechanism including an electrical igniter, an ignition circuit, a switch in the ignition circuit, and means for operating the switch, includng a pressure-responsve means, and an electrically operated thermal means co-acting therewith and arranged upon initiation of operation of the burner mechanism to operate the switch a predetermined time thereafter.

. 2. In an electrically operated and controlled fluid fuel pressure burner mechanism including anelectrical igniter, an ignition circuit, a normally closed ignition switch therein for establishing said circuit upon operation of the burner mechanism, means to open the ignition switch actuated a predetermined time after establish-' ment of the ignition circuit including means to render the opening means partly eifectivedethe burner is idle, means to open the ignition switch actuated a predetermined time after energization of the ignition circuit including means to render the opening means partly effective dependent upon the establishment of the normal fluid fuel operating pressure and additional operative upon the establishment of the normal fluid fuel operating pressure upon operation of the burner followed by the action of an electrically operated time actuator operative upon the energization of the ignition circuit. 1

6. The structure of claim 5 wherein said pressure operated means is adapted to maintain the ignition circuit open when opened by said time actuator.

7. In an electrically operated and controlled fluid fuel pressure burner mechanism including an electrical ignition, an ignition circuit and a normally closed ignition switch therein when the burner mechanism is idle, means for tilting the switch to, open the ignition circuit, means responsive to the pressure of the fluid fuel, a connection between the tilting means and pressure responsive means arranged upon an increase in fluidiuel pressure upon initiation oi. operation of the burner mechanism to partially operate the tilting means, and thermally operated means actuated by the passage of current through the normally closed ignition circuit to complete the tilting of the switch'to open the ignition circuit.

8. The structure of claim '7 wherein said tilting means is responsive only to said pressure responsive means to close said switch.

9. The structure of claim '7 whereimthe connection between thetilting and pressure means includes a link having a lost motion connection to one of said means rendered operative to complete the operation of the tilting means upon operation of the thermally operated means.

10. The structure of claim 7 wherein the thermally operated means includes a heating element in the ignition circuit and a thermal member arranged to be actuated thereby to impart additional movement to the said connection.

'11. The structure of claim '7 wherein the thermally operated means is mounted upon said connection.

12. The structure of claim 'I wherein the connectionv between the tilting and pressure means includes a link having a lost motion connection to one of said means rendered operative to complete theoperation of the tilting means upon operation of the thermally ope ated means, and wherein the thermally operated eans includes a heating element in the ignition circuit and a thermal member mounted upon said connection adapted to be actuated by the heating element to impart additional movement to the-said con nectlon.

.13. In an electrically operated and controlled fluid fuel pressure-burner mechanism including an electrical ignition device, an ignition circuit and a magnetically operated switch therein, a magnetic actuator therefor normally closing the ignition switch when the burner mechanism is idle, means responsive to the pressure of the fluid fuel arranged to engage said magnetic actuator and arranged upon an increase in fluid fuel pres.-

sure upon initiation of operation or the burner mechanism to change the relation of the actuator to the switch, and thermally operated means actuated by the continued passage of the current through the normally closed ignition circuit to continue the change of the relation of the magnetic actuator to open the ignition switch.

14. The structure of claim 13, wherein the said magnetic switch includes a flexible electrode mounting an armature, and the magnetic actuator includes a source of magnetic energy ar-" ranged to close the switch when the relation of the actuator to the switch brings the armature within the operative field oi the magnetic actuator.

15. The structure or claim 13, wherein the thermally operated means includes a heating element in the ignition circuit and a thermal member adapted to be actuated thereby to move the sfitch out 0! the operative influence of the actua r.

16. The structure of claim 13, wherein the magnetic actuator includes a source of magnetic energy mounted upon a' bracket engaged by the said pressure responsive member and a stop to limit its movement upon an increase in fluid fuel pressure.

17. The structure of claim 13, wherein the magnetic actuator includes a source of magnetic energy mounted upon-a swinging bracket engaged by the said pressure ve member anda stopto limit its movement upon an increase in fluid fuel pressure, and wherein the thermally operated means includes a heating element in the ignition circuit and a thermal member responsive thereto actuated by the heating element to move the switch out of the operative influence oi the magnetic actuator.

18. In an electrically operated and controlled fluid fuel pressure burner mechaninn having an electrical ignition device, an ignition circuit therefor including a normally open ignition switch when the burner is idle, an electrically operated means included in the ignition circuit, and means actuated'by the establishment of a predetermined fluid iuel pressure upon-operation oi the burner to close the ignition switch and upon a predetermined increase in pressure therebeyond to render eflective said electrically operated means to open the ignition switch, actuated a predetermined time after energisation oi the ignition circuit.

19. In an electrically operated and controlled erated time actuator included in the ignition cir-V cuit andvmeans to open the switch made operative by the conjoint action of the pressure responsive means and the said electrically operated time actuator, the operation or the latter a predetermined time after energisation of the ignition circuit rendered eii'ective to operate the switch opening means by the supplementary actuation of the switching means by the pressure means responding to the fluid incl reachingthe normal burner operating pressure. 7

20; In an electrically operated and controlled fluid fuel pressure burner mechanism having an electrical ignition device, an ignition circuit and a jmagnetically operated switch'therein, a magtuator a predetermined time after the closing of the ignition switch to open said switch, said pressure actuated means including additional adjustable means limiting the opening of the ignition switch by said thermal means until the fluid iuel has attained normal operating pressure.

21. The structure of claim 20, wherein said magnetic switch includes a flexible electrode mounting an armature and the magnetic actuator includes a source of magnetic energy mounted upon a pivoted arm having 'suflicient magnetic intensity to normally hold the actuator when said armature is brought within the operative magnetic held to maintain the ignition switch closed.

22. The structure of claim 20, wherein the means interposed between the pressure responsive device and the actuator includes a recipro cable bracket operated by the pressure responsive means to engage the actuator when the burner mechanism is idle to open the switch.

23. The structure of claim 20, wherein the means interposed between the pressure responsive device and the actuator; includes a reciprocable bracket operated by the pressure responsive means to engage the actuator when the burner mechanism is idle to open the switch, and yielding means opposing the action oi the bracket to open the switch operable to operate the actuator to close the switch when the bracket trees the actuator.

24. The structure of claim 20, wherein said magnetic switch includes a flexible electrode mounting an armature, and the magnetic actuator includes a source of magnetic energy mounted upon a pivoted arm to normally hold the actuator when said armature is brought within the magnetic field, and wherein the thermally operated means includes a heating element in the ignition circuit and a thermal element provided with an abutment adapted to engage the said arm, said element actuated by the heating element to rotate the-actuator arm to open the ignitlon switch.

magnetic switch includes a flexible electrodemounting an armature, and the magnetic actuator includes a source of magnetic energy mounted upon a pivoted arm having an arm to normally hold the actuator when the said armature is brought within the magnetic fleld, wherein the means interposed between the pressure responsive device and the actuator includes a reciprocable bracket operated by the pressure responsive means to engage the actuator Jvhen the burner mechanism is idle to open the switch and to free the actuator upon an increase in fluid fuel pressure, and wherein-the thermally operated means includes a heating element in the ignition circuit and a thermal element provided with an abutment adapted to engage the said arm, said element actuated by the heating element to rotate the actuator arm to open the ignition switch.

26. In an electrically operated and controlled fluid pressure burner mechanism including an electrical igniter, an ignition circuit, a switch in the ignition circuit, and means for operating the switch including a pressure-responsivemeans, and an electrically operated thermal means coacting therewith and arranged for the pressureresponsive means, upon initiation of the operation of the burner mechanism to permit, a predetermined time thereafter, the operation of the thermal means to open the switch,

2'1. In an electrically operated and controlled fluid fuel pressure burner mechanism including an electrical igniter, an ignition circuit, an ignition switch therein for establishing said circuit upon operation of the burner mechansm, means to actuate the ignition switch, a timed actuator therefor operative upon establishment of the burner circuit, and of such limited action when operative as to normally have no effect upon said means, means responsive to the-fluid fuel pressure delivered to the burner nozzle operating upon the establishment of the normal operating pressure to render the action of the timed actuator effective to open the switch.

28. In an electrically operated and controlled fluid fuel pressure burner mechanism including an electrical igniter, an ignition circuit, including therein a closed ignition switch when the burner is idle, means to actuate the ignition switch, a timed actuator therefor operative upon establishment of the burner circuit, and of such 5 limited action when operative as to normally have no eflect upon said means, means responsive to the fluid fuel pressure delivered to the burner nozzle operating upon the establishment of the normal operating pressure to render the action of timed actuator eifective to open the switch, said pressure responsive means upon a loss of said normal pressure acting to close said switch.

29. The structure of claim 26 wherein said pressure responsive means upon a predetermined ing said circuit upon operation of the pressure mechanism, operating means for said switch, electrically operated means to partly actuate the switch operating means a predetermined time after the establishment of the ignition circuit, and means actuated by the establishment of the normal fluid fuel operating pressure to render the action of the first means, when operative, effective to open the switch. v

32. In an electrically operated and controlled fluid fuel pressure burner mechanism including an electrical igniter, an ignition circuit, including a normally closed ignition switch when the burner is idle, operating means for said switch, electrically operated means to partly actuate the switch operating means a predetermined time after the establishment of the ignition circuit, and means actuated by the establishment of the normal fluid fuel operating pressureto render the action of the first means, when operative, eifective to open the switch.

me E. MCCABE.