US1986031A

US1986031A - Oil burner control

Info

Publication number: US1986031A
Application number: US430482A
Authority: US
Inventors: George R Townsend
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1930-02-24
Filing date: 1930-02-24
Publication date: 1935-01-01
Anticipated expiration: 1952-01-01

Description

Jan. 1, 1935. G, R. TOWNSEND 1,985,031

OIL BURNER CONTROL Filed F'eb. 24, 1930 7g3 l 9 622 79 l Inventob: Geer/*ge R. Townsend,

His Attorneu Patented Jan. 1, 1935 PATEN y@FFICE incensi om BURNER ooN'rnoL George R. Townsend, Schenectady, N. Y., assigner to General Electric Company, a corporation of New York Application February 24, 19st, serian No. 430,482

23 Claims.

My invention relates to control devices, and has for its principal object a fully automatic control device for a burner for fluids.

Such an automatic oil burner is set forth in a copending application of Chester I. Hall, Serial No. 430,497, filed Feb. 24, 1930, and assigned to the same assignee as this application.

The present invention is an improvement of the device therein set forth and claimed, and of the device set forth and claimed in a copending application of Harry R. Crago, Serial No. 430,- 480, filed Feb. 24, 1930, and assigned to the same assignee.

The usual fluid fuel burner employs an electrically driven fuel supply motor for furnishing fuel to the combustion chamber of the oil burner furnace. Some means for igniting the fuel is necessary and this is usually an electrical ignition system. A control mechanism is usually provided for controlling operation of the fuel supply motor and ignition systems. A room thermostat responsive to room temperatures in turn-controls operation of the control mechanism to start and stop the burner in response to temperature variations.

The preferred embodiment of my invention consists of a synchronous motor for continuously driving a time controlled mechanism which automatically switches in the night or day thermostats which initiate operation of the apparatus. The time control mechanism does not form a part of this application but is described and claimed in my copending application, Serial No. 399,835, filed Oct. 15, 1929, and assigned to the same assignee.

The motor also drives what is termed a recycling mechanism. This device opens and closes the fuel supply motor circuit at short intervals. It may be used to open and close a valve or any ,w other device which controls the fuel supply. The

purpose of such an operation is to present several opportunities for igniting the oil spray.

Although the ignition system for igniting the oil flame may be continuously energized until flame is established, in my invention, the recycling mechanism causes the ignition system to be energized and deenergized simultaneously with the fuel supply motor.

When the flame is established a heat responsive device placed in the rebox of the furnace and operated by the name cuts out the ignition system and locks in the fuel supply motor. This flame responsive device may also be placed in the stack.

Should the flame fail during operation, the heat responsive device energzes the recycling mechanism to reignite the oil by reenergizing the ignition system. A denite time period is provided after flame failure before the ignition and fuel supply motor circuits are reestablished by the recycling device. This is accomplished by the setting of cams carried on a cam shaft, and forming part of the recycling mechanism.

In the present invention means are provided for permitting relative adjustment of the cams whereby the time intervals in energization and deenergization of the fuel supply motor` and ignition system may be varied.

The recycling operation is accomplished by means of cam actuated contacts, which contacts are rendered operative whenever a starting coil is energized by the closing of a thermostat calling for heat. The starting coil operates a pivoted member upon which relatively adjustable cams are mounted, the pivoted member also carrying circuit closing contacts. This brings the cam shaft into engagement with a driving pinion of the synchronous motor. The rotation of the cams actuates the contacts'to open and close the ignition system and fuel supply motor circuits. In the event that the recycling device fails to cause ignition of the fuel after a predetermined number of intermittent operations of the fuel supply motor and ignition system, a tripping means is provided for rendering the control apparatus inoperative, thus inviting inspection to determine the cause of the failure of the apparatus to function.

My invention will be better understood from the following description when considered in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

The drawing shows a schematic diagram of the device with the improvements thereon.

Referring to the drawing, furnace 60 has mounted adjacent thereto the fuel supply apparatus having a fuel supply motor 100, for directing fuel therein. Within the combustion chamber are mounted the ignition electrodes 103 and the thermostatic portion of the switch 104 which is responsive to combustion conditions within the furnace. A safety pressure device 107 is mounted on top of the furnace.

The control mechanism includes a synchronous motor 61 which is continuously energized from the power supply lines L3 and L; by means of

conductors

91 and 61. A time control switch designated generally -at 62 is driven through reduction gearing 110 by means of the synchronous motor 61.

y attached to the back panel (not shown).

The pivoted

members

621 and 622 are mounted on a shaft supported by the brackets 119 and 120 These members are biased in a clockwise direction by means of the springs 123 and 122. The pivoted member 621 carries contacts 111 and-112 electrically insulated from each other and pivoted member 622 carries double contacts 113. The

cams

114 and 115 with which the pivoted members have engagement operate the pivoted members so that the double contact 113 will be in contact with the lower contact 112 to place thermostat 94 in the controlling circuit or in contact with the upper contact 111 to place the thermostat 93 in the controlling circuit. These circuits will be traced below. The driving shaft 160 upon which the

cams

114 and 115 are rotatably mounted has xed thereto the dial 161. The cams are operably connected to the drive shaft 160 by mean-s of the adjusting members 117 and 118 which releasably engage the dial 161. The adjusting members 117 and 118 are connected to the cams for the purpose of shifting the position of the cams on the shaft with respect to each other to determine the time at which the contacts 113, 112, and 111 will be shifted with respect to each other. A stop mem* ber 121 connected to the back panel (not shown) and co-acting with the lug on the pivoted member 622 limits the clockwise movement of the pivoted members when the members are not in contact with the cams.

Therecycling mechanism includes a frame 68 pivotally supported in

brackets

132 and 133 attached to a back panel, not shown. This frame carries an armature 68 for rotating the frame clockwise whenever the pick-up or starting magnet 67 is energized. The arms 7l and 69' are also carried by the frame and rotate therewith. These arms rotatively support the cam shaft 124 upon which are mounted the driving gear 66 and the recycling cams 63 and 64. A spring 124' is for the purpose of returning the cam shaft to its initial position whenever the frame drops back from its operating position against the stop 67 attached to a back panel, not shown. Whenever the electromagnet 67 is energized it causes the armature 68 to rotatethe frame in a. clockwise direction to mesh the driving gear 66 with the gear 65 driven by the motor 61. This causes rotation of the cams 63 and 64 in a direction indicated by the arrow (on gear 66 to operate the pivoted members 74 and 73 for controlling the motor and ignition circuits in` a manner to be described later.. A stop 67 referred to, limits the counter-clockwise movement of the frame when the frame is permitted to return to the inoperative position.

vCarried by frame 68 is a member 69 of insulating material which carries a bridging member 69' carrying contacts. These contacts cooperate with the contacts 135 and 136 on brackets which are attached to the back panel, not shown, for completing the ignition circuit. to be described below. Bracket and contact 136 are electrically connected to pivoted member 74. The arm 71 carries a member 70 of insulating material which cooperates with a member 711 for controlling a holding circuit to be described.

The member 711 is pivotally mounted Ona bracket 125 attached to the back panel, not

- shown.. To its lower end is attached by means of an insulating member the bridging member 126 which rcarries contacts cooperating with the

contacts

137 and 138 to complete a holding circuit to be described below.

Contacts

137 and 138 are supported by brackets 139 and 140 attached to the back panel, not shown. When the frame 68 is rotated in a clockwise direction to mesh gears 65 and 66, the member 70 rotates the member 711 in a clockwise direction to close bridging member 126 on

contacts

137 and 138. When the electro-magnet 72 mounted upon the back panel, not shown, is energized, it maintains the member 711 in the closed position.

The pivoted switch members 73 and 74 carrying the contacts 75 and 76 are mounted in the brackets 128 and 127 vwhich are 'attached to the back panel, not shown. Spring members 731 and 74" bias the switch members in a counterclockwise direction so that when the frame 68 is in its inoperative position,v the lug 130 carried by pivoted member 73 contacts with the pin 130 which acts as a stop member and which is carried by bracket 128. The lug 1271 carried by the pivoted member 74 co-acts with the stop member 127 carried by the bracket 127. The pivoted member 73 has an ear 129 which pivotally supports a latch 73' which, when the pivoted member 73 is in its biased position against the pin 130,' is maintained in a raised position, as shown, by means of the pin 130 cooperating with the depending lug 129 on latch 73. When the pivoted member 73 is rotated in a clockwise direction the lug 4129 on latch 73 being moved out of engagement with the pin 130 drops behind the member 711 to engage the same for a purpose to be described below.

When the frame 68 is rotated in a clockwise.

direction, the cams 63 and 64 contact with the curved upper ends of pivoted members 74 and 73 and rotate them in a clockwise direction. The detailed operation of the cams and switch members will be described below.

An overload tripping device includes a frame pivotally mounted in the bracket 801 attached to the back panel, not shown. A spring 80 biases the frame in a clockwise direction about its pivot. The frame has pivotally mounted thereon at 77 the latch member 77 which carries the lug 79. This lug is provided with a recess 792 into which the catch 79 ts and normally holds the frame 80, as shown, against its bias. The catch is rigidly supported by the back panel, not shown. Mounted on the other end of the frame 80 and insulated therefrom is the bridging member 81 carrying contacts which cooperate with the

contacts

141 and 143 to complete a circuit, to be described later. The

contacts

141 and 143 are supported by the brackets 142 and 139 attached to the back panel, not shown.

Carried by the gear 66 is a pin 78 which cooperates with the latch 77 to rotate the same in a clockwise direction about its pivot 77 to release the lug 79 from the catch 79. This permits the biasing spring 80 to rotate the frame 80 about its pivot in a clockwise direction and move -the bridging member 81 to an open position out of contact with the

contacts

141 and 143. This opens a circuit to be described below.

The period of time necessary for the recycling .device to cycle out, that is for the mechanism to actuate the fuel supply motor and ignition system a predetermined number of times and then be tripped out of operation is constant. The period of time during which the fuel supply motor and ignition system remain energized and deenergized may be varied however.

This is accomplished by means of the cams 63 and 64. It will be seen that cam 63 carries thereon a collar 631 provided with teeth. Cam 64 carries the collar 641 having a single tooth engaging with teeth on cam 63. By rotating cam 64 with respect to 63 in a counter-clockwise direction, and engaging different teeth on cam 63, the cam surfaces will be shifted with respect to each other due to the fact that the teeth on 63 are of different spacing than the notches on the face of the cam 64. This affects the time of opening and closing of the contacts 75 and 76 in the fuel supply. motor and ignition circuits since the pivoted members 74 and 73 are actuated according to the position of thecam surfaces.

The fuel supply motor is connected to one side of the vline La by means of conductor 101. The other side of the motor is connected to the recycling device through conductor 102. The ignition terminals 103 are connected to the ignition transformer 91 by means of

conductors

149 and 150. A thermostatically operated switch mechanism 104 responsive to heat conditions in the furnace is placed in the rebox of the furnace 60 and is provided with two contacts/for completing circuits described below through conductor or 106. This switch is described and claimed in my copending application No. 417,923, led Jan. 2, 1930, and assigned to the same assignee. A safety switch 107 connected to

conductors

147 and 148 is placed on the furnace for interrupting the circuit to the transformer 90 in case of excessive pressures.

The operation of the apparatus is as follows. The primary of transformer V90 is normally continuously energized from the supply lines La and L4 by means of conductor 146, and conductor 147, safety device 107 and conductor 148. As shown, thermostat 94 is the thermostat which controls the circuit. When the thermostat moves to the left hand contact calling for heat a circuit is completed from the upper side of the low voltage secondary of transformer 90, thermostat 94, conductor 144 the contacts 112 and 113 on the time switch 62, conductor 71', bracket 139, the contact 143, bridging member 81, contact 141, member 142, conductqr 145, starting coil 67, through conductor 105, the switch 104 which in its cold position is upon the right hand contact, conductor 104- to the lower side of the secondary of transformer 90. This energizes the coil 67 which actsupon armature 68 to rotate the frame 68 about its pivots in a clockwise direction. This operation of the frame 68 meshes thepinion 65 driven by the synchronous motor 61 and the gear 66 which results in a counter-clockwise rotation of the cam shaft carrying cams 63 and 64. At this movement of the frame the cams 63 and 64 are brought into contact with the pivoted members 74 and 73 thus placing the members 74 and 73 under the control of the cams as will be described in detail below. The insulating member 70 carried by arm 71 causes the member 711 to be moved about its pivot in a clockwise direction closing the bridging member 126 carried at its lower end on

contacts

137 and 138. Closing of these contacts locks the coil 67 across the line thereby relieving the thermostat 94 of carrying the current which might damage the thermo-A starting coil 67, from the other side of the starting coil through conductor 105, right hand contact of the switch 104, conductor 104', to the lower side of the transformer 90. The bridging member 691, carried by arm 69 closes on contacts and 136 to complete the circuit from conductor 92 to the pivoted member 74 to energize,

the ignition transformer as set forth below.

The detailed operation of the cams and pivoted switch members 73 and 74 is as follows: As the frame 68 is moved by the coil 67 in a clockwise direction the raised portion of cam 63 contacts with the curved upper end of pivoted member 74 and moves it in a clockwise direction against the bias of its spring 74. Upon further clockwise movement of the frame Y68, the curved upper end of pivoted member 73 contacts with the bottom of a depression in the cam 64. From this point on both pivoted members 73 and 74 move in a clockwise direction, the contacts 75 and 76 being open. When the gear 66 meshes with the gear 65, movement of frame 68 in a clockwise direction ceases and counterclockwise rotation of the cams 63 and 64 begins.

As the camsrotate, the upper end of pivoted member 73 engages the beginning of the iirst raised portion of the cam 64, and begins rotating the member 73 further in a clockwise direction. Just as the upper end of member 73 reaches the topI of the raised portion of cam 64 during this clockwise movement of member 73, the upper end of member 74 drops into the rst depression of the cam 63 rotating in a counterclockwise direction closing contact 76 on 75 with a snap action. The member 73 then acts as a stop member for the member 74. This closes the ignition and the motor circuits.

The circuit through the fuel supply motor 100 may be traced from the line L3, conductor 146, conductor 101, motor 100, conductor 102, pivoted member 74, contacts 76 and 75, pivoted member 73, conductor 131, conductor 147, safety device 107, conductor 148, to the other side of the line L1.

The circuit through the primary of the ignition transformer may be traced from line La, conductor 91, primary of transformer 91, conductor 92, bracket and contact 135, bridging member 691, contact and bracket 136, pivoted member 74, contacts 76 and 75, pivoted member 73, conductor 131, conductor 147, safety device 107, conductor l48, back to the other side of the 1`ne L4.

This causes the motor 100 to supply a fine spray of oil to the re box. At the same time an arc will be produced across the terminals 103 connected to the secondary of transformer 91 by means of

conductors

149 and 150 for igniting the oil. When a ame is established the switch 104 `due to the heat of the flame operates to close on the left hand contact. This results in the opening of the circuit through the starting coil 67, permitting the frame 68 to pivot in a counterclockwise direction to its normally opened position thus opening the ignition transformer circuit through bridging member 691. Before the circuit through coil 67 is broken, a circuit for energizing coil 72 is completed from the lower side of the secondary of transformer 90, through the conductor 104', switch 104, which momentarily bridges both contacts, the left hand contact, conductor 106, to one side of the holding coil 72, from the other side of coil 72 to bracket 142, contact 141, bridging member 81, contact 143, bracket 139, contact 137, bridging member 126, contact 138, bracket 140, conductor to the upper side of secondary of transformer 90. Coil 72 thus energized retains the pivoted member 711 in its attracted position. This keeps the bridging member 126 closed on

contacts

137 and 138 locking the coil 72 across the secondary of transformer until the secondary of transformer 90 is shorted vby thermostat 94. The latch member 73 mounted on pivoted member 73 and in contact with the member 711, retains the pivoted members 73 and 74 in a position to keep the contacts 75 and 76 closed, thus keeping the motor circuit closed across the lines L3, L4. Thus until a change is called for by the thermostat, the fuel supply motor operates to supply a spray of oil to the nre box of the furnace 60.

If the flame is not established while the ignition and motor circuits are closed the frame will remain in operating position and the cams will continue to rotate since the cam shaft is in driving relation with the gear 65. As the cams rotate, the upper end of pivoted member 73 rides along the top part of the rst raised portion of cam 64, the contacts 75 and 76 being maintained in the closed position. The beginning of the rst raised portion of cam 63 comes opposite the upper curved end of member 74 just as the second depression on the cam 64 reaches the upper end of member 73. This permits the member 73 to drop into the second depression and be rotated in a counter-clockwise direction by biasing spring 731. Pivoted member 74 is also rotated in a counterclockwise direction by means of its spring 74', the contacts 75 and 76 being maintained closed. However, when the upper end of pivoted member 74 contacts with the cam 63, further counterclockwise movement of the member 74 is prevented and since the member 73 continues to rotate in a counter-clockwise direction until the upper end of this member contacts with the bottom of the second depression on cam 64, contacts 75 and 76 open with a snap action. This opens the motor and ignition circuits.

The cams continue to rotate, the upper end of member 74 reaching the top part of the first raised portion of cam 63 and riding along the same. The upper end of member 73 starts up the incline of the second raised portion of cam 64 just as the upper end of member 74 drops into the second depression on cam 63 rotating in a counter-clockwise direction and again closing the contacts 76 and 75, thus reenergizing the motor and ignition circuits. If a flame is not established after a predetermined number of such operations, pin 78 mounted upon the gear 66 will contact with the upper end of latch member 77 rotating this member about its pivot 77 in a clockwise direction to release lug 79 by moving the recess 792 from the catch 79. This permits the spring 80 attached to the pivoted frame member 80 which carries latch 77 to rotate the frame 80 in a clockwise direction about its pivot 801 moving the bridging member 81 and away from

contacts

141 and 143 and opening the circuit through the starting coil 67. The apparatus cannot again beset into operation until the latch member 77 is manually reset.

By interchanging the conductors connected to pivoted members 73 and 74, the ignition transformer can be continuously energized during the intermittent operation of the motor. The circuit through the primary of the ignition transformer would then be from line La, conductor 91' to one side of ignition transformer 91, from the other side of ignition transformer 91, conductor 92, bracket and contact 135, bridging member 691, contact and bracket 136, pivoted member 74, conductor 131, conductor 147, safety device 107, con-I ductor 148, to the other side of the line L4. Thus while frame 68 is in closed position placing the bridging member across contacts 135 and 136, the ignition transformer will be continuously energized.

Should the fiame for any reason fail during operation of the furnace, the recycling mecha- 'nism as described above, will again be set into operation to establish a flame when the switch 104 on cooling closes on the right hand contact and makes a circuit through the conductor 105 to energize coil 67. Due to the setting of the cams 63 and 64 a definite time period elapses before the fuel supply motor and ignition system are re-energized as has been described above in detail, thus permitting accumulated gases to be expelled from the furnace.

Upon failure of voltage after ame is established, the holding coil 72 becomes deenergized. There is no force to then hold the pivoted member 711 in its attracted position to maintain the bridging member 126 in contact with

contacts

137 and 138. The latch 73 holding pivoted members 73 and.74 with the contacts 75 and 76 closed, is released as the pivoted member 711 rotates in a counter-clockwise direction to the open position. Pivoted members 73 and 74 rotate in a counter-clockwise direction opening the contacts 75 and 76 and return to their biased positions with the lugs 1271 and against the stop member 127 and pin 130. Operation of the apparatus is again established when the voltage comes back upon the lines and the recycling is again brought into operation.

If suicient time has not elapsed for the switch 104 to return to its cool position due to only a momentary failure of voltage, if the thermostat 94 is still calling for heat, coil 72 will be reenergized and attract the pivoted member 711 to its closed position. This places the coil 72 across the transformer and relieves the thermostat of the duty of carrying current. Since the latch member 73 is in the raised position, the pivoted member 73 will not be operated to close contacts 75 and 76 and hence the fuel supply motor will not be energized until the switch 104 returns to the cold position and the recycling apparatus is again set into operation.

With the ame established and a proper room temperature attained, the thermostat 94 will move to the right hand position. The closing of the right hand contact shorts the secondary of the transformer 90. The short-oircuiting circuit can be traced from the lower side of transformer 90, right hand contact of thermostat 94, conductor 144, contacts 112 and 113, conductor 71', bracket 139, contact 137, bridging member 126, contact 138, bracket 140, conductor to the upper side of the transformer 90. This deenergizes the holding coil 72 and permits the pivoted member 711 to return to its open position. Contacts 75 and 76 are also moved tothe open position when the members 73 and 74 are rotated in a counter-clockwise direction against stops 130 and 127 by their biasing springs 731 and 74 deenergizing the motor 100. This is because member 711 and latch 73 are released from latching position when stop pin 130 reengages lug 129' on latch 73. When the room temperature has cooled to the lower limit, the thermostat again operates to call the apparatus into operation to furnish more heat.

Mounted on top of the furnace 60 is a safety device 107 which may be thermostatically operated or operated by an excessive boiler pressure. This device normally closed, upon dangerous heat conditions, opens one side of the circuit made by

conductors

147 and 148 to the primary of the transformer 90, thus deenergizing the holding coil 72 and shutting down the apparatus. When normal conditions are again obtained the device 107 closes and should the thermostat call for more heat the recycling operation again takes place.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the purpose involved. It will be apparent h Wever, that the invention is susceptible of being odified to meet the different conditions encountered in its use and I therefore aim to .cover by the appended claims all modifications Within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. In an oil burner control device, a driving means, a fuel supply motor, circuit making and breaking means for controlling said fuel supply motor, a cam shaft carrying circuit making and\ breaking\cams cooperating therewith, movable means supporting said cam shaft, electroresponsive means for moving said last means to permit said driving means to rotate said cam shaft to energize said motor, a pivoted circuit closing and opening member which is moved to the closed position by said movable camshaft supporting means upon movement of said cam shaft supporting means to driving position, latching means associated With said first circuit making and breaking means cooperating with said member to retain said first circuit-making and breaking means in circuit making position to maintain said motor energized under certain conditions, a second electro-responsive means for holding said member in the closed position upon return of said cam supporting means to initial position, and means for deenergizing said first electro responsive means and energizing said second electro-responsive means under said certain conditions.

2. In a control for a heating device, electrically driven heating means, an electrical circuit therefor, circuit opening and closing means for controlling said circuit, a movable member carrying means adapted to ,control said circuit opening and closing means, driving means for said last control means, electro-responsive means for moving said movable member and control means carried thereby to control said circuit opening andclosing means for energizing said heating means, a second electro-responsive means, a movable armature therefor, and vlatching means on' said circuit opening and closing means for cooperating with said armature to hold" said circuit opening and closing means in a circuit closing position to maintain said heating means energized when said first electro-responsive means is deenergized allowing said movable member and control means to return to initial position, and thermostatic means for controlling operation of both of said electro-responsive means. y

3. In a control device for an oil burner, a fuel supply motor, circuit controlling members for controlling said fuel supply motor, a cam shaft v carrying cams adapted to cooperate therewith,

driving means for said camshaft, a movable member supporting said cam shaft, a movable circuit opening and closing member biased to open position, electro-responsive means for moving said cam shaft supporting member to render said cam shaft operative, and means on said cam shaft supporting member whereby movement of the same to operative position will move the movable circuit-opening and closing member for retaining said first members in circuit controlling position to maintain said fuel supply motor energized when the cam shaft supporting member and cams return to initial position and said second electro-responsive means is energized to hold said last member in circuit controlling position, and thermostatic means for controlling operation of both of said electro-responsive means.

4. In a control device for an oil burner, a fuel supply motor, an ignition system, electrical circuits therefor, a plurality of electro-responsive means, pivoted circuit opening and closing means for controlling said circuits, one of said pivoted means being provided with a latch by means of which said pivoted means can be kept in circuit closing position to maintain said fuel supply motor energized, a pivoted member'actuated by one of said electro-responsive means supporting cams for engaging with said pivoted circuit opening and closing means to control the same, driving means for said cams, a second pivoted member adjacent another of said electro-responsive means provided with a latch engaging portion, means on said first pivoted member to actuate said second pivoted member upon energization of the electro-responsive means actuating the rst pivoted member to cause said cams to engage said circuit opening and closing means, said latch and latch engaging portion of said second pivoted member cooperating to keep said circuit opening and closing means in a closed position When said second electro-responsive device is energized and said first electro-responsive means is deenergized to permit said first pivoted member to return to its initial position, and means for controlling energization of both of said electro-responsive means.

5. In a control device for an oil burner, a fuel Supply motor, an ignition system, electrical circuits therefor, a plurality of electro-responsive means, pivoted circuit opening and closing means for controlling said circuits, one of said pivoted means being provided with a latch by means of which said pivoted means can be kept in circuit closing position to maintain said fuel supply motor energized, a pivoted member actuated by one of said electro-responsive means supporting cams for engaging with said; pivoted circuit opening and closing means to control the same, driving means for said cams, a stationary pin cooperating with said latch to retain said latch in a raised position until said pivoted member is actuated by one of said electro-responsive means, a second pivoted member adjacent another of said electro-responsive means provided with a latch engaging portion, means on said first pivoted member to actuate said second pivoted member upon energization of the electro-responsive means actuating the first pivoted member to cause said cams to engage said circuit opening and closing means, said latch and the latch engaging portion of said second pivoted member cooperating to keep said circuit opening and closing means in a closed position when said second electro-responsive device is energized and said rst electro-responsive meansi's deenergized to permit said first pivoted member to return to its initial position.

6. In a control device for an oil burner, a fuel supply motor, a circuit therefor, a pair of pivoted members having a cam engaging portion at one end and carrying an electrical contact at thel other end, said contacts cooperating with each other to open and close the circuit to energize said motor, said contacts being initially in the open' position, individual cams mounted adjacent the cam engaging portion of said pivoted members and cooperating therewith to move said pivoted members to open and close said contacts with a snap action, means for driving said cams, said cams being formed to permit several operations of said contacts to intermittently energize said motor and means for thereafter rendering said cams ineffective whereby said contacts will remain in the open position, and means permitting relative adjustment of said cams to vary the time said contacts remain in the open and closed positions during the above operation.

7. In an oil burner control means, a fuel supply motor, an ignition system therefor, a plurality of cam actuated circuit controlling members for controlling said motor and ignition system, cams mounted on a movable shaft and adapted to intermittently actuate said circuit controlling members, driving means for said cams, said cams being relatively adjustable to permit the periods said circuit controlling members-are opened and closed to be varied, electro-responsive means to move said shaft and cams to an operating position to actuate said circuit controlling members to energize said motor and ignition system for initiating combustion, a second electro-responsive device operative only after heating conditions are established and means cooperating therewith and with said circuit controlling members for maintaining said fuel supply motorv energized to maintain combustion, a means responsive to said combustion for deenergizing said first electro-responsive means to permit said camshaft and cams to return to initial position and to energize said second electro-responsive means to maintain combustion and thermostatic means for deenergizing said second electro-responsive means when a suffcient amount of heat is furnished.

8. In an oil burner control, a fuel supply motor and ignition system therefor, a pair of cooperating cam actuated circuit controlling members for intermittently energizing said motor and ignition system, cams relatively adjustable to vary theI peri-ods said circuit controlling members are in the open and closed position, means adapted to drive said cams, an electro-responsive means controlling operation of said cams by saiddriving means to cause intermittent operation of said fuel supply motor to initiate heating conditions, a second electro-responsive means having latching mechanism cooperating with one of said cam actuated circuit controlling members to maintain said fuel supply motor energized after heating conditions have been established, heat responsive means operatively associated with both of said electro-responsive means for preventing energization of said electro-responsive initiating means after a combustion failure until initial conditions are obtained, and thermostatic means menacer than a sufficient amount of heat is furnished to maintain heating conditions.

9. In a heat control apparatus, an electrically operated fuel projecting means, circuit making and breaking devices for controlling the fuel projecting means, electrically operated means for intermittently actuating said devices, a trip mechanism provided with a circuit opening and closing member for controlling said electrically operated fuel projecting means, means actuated by said intermittent actuating means to actuate said trip mechanism after a predetermined number of intermittent operations' to render said actuating means ineffective to actuate said circuit making and breaking devices, and means on said trip mechanism for manually operating said trip mechanism to deenergize said electrically operated fuel projecting means after it has been once energized and for resetting said trip mechanism to permit said fuel projecting means to be again intermittently operated.

l0. A control for a burner, including electrically driven fuel projecting means, circuit-making and breaking means for controlling said fuel projecting means, an electrically driven cam mechanism for intermittently operating said circuit-making and breakingY means to energize said fuel projecting means, and a trip switch mechanism `operated by said electrically driven cam mechanism to render said cam mechanism ineffective after a predetermined number of intermittent operations.'

11. A control apparatus for a burner, including electrically driven fuel projecting means, circuitmaking and breaking means for controlling energization of said fuel projecting means, electrically driven cam mechanism for operating said circuit-making and breaking means, and a trip mechanism provided with a circuit-making and breaking member actuated by said cam mechanism after a predetermined number of intermittent operations to render said cam mechanism ineifective.

12. A control device for a burner having an y electrically driven fuel projecting motor, including circuit controlling mechanism for said motor, electro-responsive means for operating said circuit controlling mechanism to intermittently energize said fuel projecting motor to initiate combustion, a second electro-responsive means associated with said circuit controlling mechanism for maintaining said fuel projecting motor energized when combustion is established, means responsive to combustion for deenergizing said second electro-responsive means and thereafter energizing said first electro-responsive means in response to failure of combustion and athermostat for causing energization of said rst electro-responsive means to initiate combuston and for causing deenergization of said second electro-responsive means to stop operation of said fuel supply motor when sufficient heat has been' furnished.

13. A control apparatus for a burner having an electrically driven fuel projecting means including an electro-responsive cam-operated circuit-making and breaking mechanism for intermittently energizing said fuel supply means to establish combustion, a second electro-responsive mechanism operably associated with said circuit-making and breaking mechanism and adapted to maintain said fuel projecting means energized after combustion is established, and a double circuit thermostatic means for deenergizing said second electro-responsive mechanism and energizing said first electro-responsive mechanism when combustion fails.

14. A combustion heating device having in combination, an electrically driven fuel projecting means; electrically driven cam-operated intermittent circuit-making and breaking mechanism adapted to control said fuel-projecting means, an electro-responsive device for rendering said circuit-making and breaking mechanism operative to intermittently energize said fuel projecting means to establish combustion, a second electroresponsive device operatively associated with said circuit-making and breaking mechanism to maintain said electrically driven fuel projecting means energized independently of the first electro-responsive device after combustion is established, and means responsive to combustion for deenergizing said second electro-responsive device and energizing said first electro-responsive device when combustion fails.

15. A control device for a burner having an electrically driven fuel projecting means, including circuit controlling mechanism therefor, electro-responsive means associated with said circuit controlling mechanism for energizing said electrically driven fuel projecting means to initiate combustion, a second electro-responsive means associated with said circuit controlling mechanism for maintaining said electrically driven fuel projecting means energized, a transformer operatively associated with both of said electro-responsive means, a thermostat in the secondary of said transformer for causing energization of said first electro-responsive means to initiate combustion, and means for deenergizing said second electroresponsive means and energizing said first electro-responsive means when combustion fails, said thermostat shortcircuiting the secondary of said transformer when sufficient heat has been furnished for deenergizing said second electro-responsive means to stop operation of said electrically driven fuel projecting means.

16. A control device for a burner having an electrically driven fuel'projecting means, including circuit-controlling means therefor, a transformer having a low-voltage secondary, an electro-responsive device operatively associated with said circuit-controlling means and cooperating therewith to initiate combustion and adapted to be energized from said low-voltage secondary, a second electro-responsive device adapted to be energized from the secondary of said transformer and associated with said circuit-controlling means for maintaining said electrically driven fuel projecting means energized, a thermostat associated with said transformer for establishing a circuit through said first electro-responsive device to initiate combustion, a device responsive to the combustion conditions for causing deenergization of said second electro-responsive device and for causing energization of said first electro-responsive device When lcombustion* fails, said thermostat short-circuiting the secondary of said transformer to cause deenergization of said second A electro-responsive device to stop operation of said said fuel supply motor and ignition system to initiate combustion, electro-responsive means operatively associated with said circuit controlling mechanism for rendering said circuit controlling mechanism operative to initiate combustion, a second electro-responsive means operably associated with said circuit controlling mechanism for maintaining said fuel supply motor energized when combustion is established, means responsive to combustion conditions for deenergizing said second electro-responsive means to cause deenergization of said fuel supply motor and for re`- energizing said rst electro-responsive means to reenergize said fuel supply motor when combustion fails, means for maintaining said ignition system deenergized after fiame failure until said combustion responsive means reenergizes said first electro-responsive device to operate said intermittent circuit controlling mechanism, and a master control thermostat for energizing said first electro-responsive means to initiate combustion and to deenergize said second electro-responsive means to stop operation of said motor when sufiicient heat has been furnished.

18. In a combustion heating device, electrically driven combustion heating means, an energizing circuit therefor having relatively movable contacts therein biased to open the circuit, cam means for intermittently closing said contacts, electroresponsive means for rendering said cam means effective to close said contacts intermittently to energize said heating means, and a second electroresponsive means dependent upon energization of said first electroresponsive means for holding said contacts closed against their bias, and switching means controlled in accordance with combustion conditions for deenergizing said first electroresponsive means to render said cam means ineffective and for maintaining said second electroresponsive means energized to maintain said electrically driven combustion heating means energized.

19. In a heat control apparatus, the combination of an electric motor driven fuel feeding means, switch mechanism for intermittently energizing said means, electroresponsive means for controlling the operation of said mechanism, latch mechanism provided with a circuit controlling member connected to control the energization of said electroresponsive means, and means actuated by said intermittent switch mechanism for tripping said latch mechanism after a predetermined number of successive intermittent operations to deenergize said electrically operated means.

20. in a combustion heating device the combination of an electrically driven fuel feeding means, circuit controlling means therefor, means for intermittently operating said circuit controlling means, electroresponsive means for rendering said intermittent operating means operative to initiate combustion, a second electroresponsive means for maintaining said electrically driven fuel feeding means energized after combustion is established, and switching means responsive to combustion for preventing energization of said first electroresponsive means until after deenergization of said second electroresponsive means upon failure of combustion.

21. A control for a burner having a fuel feeding motor and an ignition system therefor including circuit controlling means for energizing said motor and ignition system. a first electroresponsive means operatively associated with said circuit controlling means for rendering said means operative to initiate combustion, a second electroresponsive means rendered operative upon operation of said first electroresponsive means and operatively associated with said circuit controlling means for maintaining said fuel feeding motor energized when combustion is established, switching means responsive to combustion conditions for deenergizing said second electroresponsive means and for reenergizing said rst electroresponsive means when combustion fails, the said second electroresponsive means being responsive to voltage failure for maintaining said ignition system and fuel supply motor deenergized until said combustion responsive means reenergizes said iirst electroresponsive means.

22. An oil burner control device including, an electrically operated oil burner, a circuit making and breaking device for intermittently energizing said burner, an electric timing means therefor, an ignition system for said burner, a movable frame carrying a cam shaft movable through a series of positions in timed sequence for intermittently actuating said circuit making and breaking device and a contact for closing a circuit to said timing means and said ignition system, electroresponsive means for moving said frame to an operative position to initiate heating conditions, a heat responsive circuit controlling device in series with said contact for deenergizing said ignition system and said timing means with said cam shaft in one of said positions to maintain heating conditions upon establishing heating conditions, and a tripping device for deenergizing said electroresponsive means if no ame is estabmessbar means and said ignition system, electroresponsive means for moving .said frame to an operative position to initiate heating conditions, a thermostat for energizing said electroresponsive means, a second member on said frame for short circuiting said thermostat when said frame moves to said operative position, a heat responsive circuit controlling device in series With said timing motor and ignition system circuit controlling member for deenergizing said ignition system and said timing means with said circuit making and breaking device in energizing position to maintain heating conditions upon establishing heating conditions, and a tripping device for deenergizing said yelectroresponsive means if no flame is established after a predetermined number of intermittent operations.

GEORGE R. TOWNSEND.