US2812806A - Electrically controlled safety igniter circuit for gas burners - Google Patents

Description

-r 1957 H. E. MORRISON ELECTRICALLY CONTROLLED SAFETY IGNITER CIRCUIT FORGAS BURNERS Filed Feb. 9, 1953 In v'n L72 r f/aro/J/Vorrz $022 mzmcoqmum mm b EE 2,812,806 Patented Nov. 12, 1957 ELECTRICALLY CONTROLLED SAFETY IGNITER CIRCUIT FOR GAS BURNERS Harold E. Morrison, St. Joseph, Mich., assignor, by mesne assignments, to Whirlpool Corporation, a corporation of Delaware Application February 9, 1953, Serial No. 335,646

6 Claims. (Cl. 158-124) trolled by an electrical circuit so arranged as to instantaneously close the gas supply and prevent unburned gas from passing through the main burner upon interruption of the electric circuit.

A further object of my invention is to provide an automatic gas igniter circuit in which a master valve is opened through the cold contact of a flame detector switch and a main burner valve is opened through the hot contact of the flame detector switch, having an electrical interlock preventing opening of the master valve upon a power interruption except through the cold contact of the flame detector switch.

A further object of my invention is to provide a simplified and novel form of control for an automatic gas pilot so arranged as to render it impossible to supply gas to the main burner when the pilot is out.

Still another object of my invention is to provide an automatic igniter for gas burners having an electrical in terlock for the master valve in the gas supply line, maintaining the valve closed upon power interruption until the system is sufliciently cool to safely turn on the gas.

Still another object of my invention is to provide an igniter circuit for a main gas burner including a flame detector switch having hot and cold contacts connected to initially turn on a master burner valve when the flame detector switch is in its cold position, and to hold the main burner valve out of the circuit until the pilot burner has been ignited, and including a shut-E switch connected in the energizing circuit for the burner valves, biased to energize the solenoid for a master gas supply valve through the cold contacts of the flame detector switch and movable to connect the solenoid of the master gas supply valve to by-pass the flame detector switch upon opening of said valve, and lockingthe master gas supply valve from. opening when the supply of power has been interrupted and is again turned on, except through the cold contacts of the flame detector switch.

These and other objects of my invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawing which diagrammatically shows an automatic igniter circuit constructed in accordancewith my invention.

In the embodimentof my invention illustrated in the drawing, the igniter safety circuit of my invention is shown as being operative to ignite and control the operation of the master valve and main burner valve. of a clothes drier, although it need not be in such a circuit and may trolling the supply of gas to a main burner 16. A pilot 123,018, filed on October 22, 1949 by Peter E. Geldhof and Harold E. Morrison, and entitled Gas Heated Drier and now Patent No. 2,635,354, dated April 21, 1953 so the drier and the circuit therefor, need only be described herein in sufii-cient detail to make my present invention readily understandable.

A gas supply line 10 is shown as delivering gas to a master gas supply valve 11 operated to open upon energization of acoil 12 of a solenoid. A pipe 13 connects the master valve 11 with a main burner valve 15 conburner 17 leads from the supply side of the main burner valve 15 to a position adjacent the burner 16, for igniting said burner when the valve 15 is turned on. The pilot burner 17 is controlled by the master valve 11 and is supplied with gas when the valve 11 is, open. The pilot burner 17 is shown as being ignited by a glow coil 19 energized by the secondary 20 of a transformer 21.

While I have herein shown a glow coil for igniting the pilot burner 17, it should be understood that a glow coil need not be employed to ignite said pilot, but that the pilot may be ignited by an interrupted spark type of igniter or by any other suitable igniting means and may even be ignited by hand if desired. The glow coil 19 is positioned adjacent the pilot 17, but for convenience in illustrating the control circuit, is shown as being remote from said pilot. The main burner valve 15 is shown as being solenoid operated, and as opening upon the energization of a coil 23 of the solenoidtherefor.

The valves .11 and 15 may be of any well known form of solenoid operated gas control valve, one form of valve construction being illustrated in my 'joint application with .Peter E. Geldhof, Serial No. 123,018 and now Patent No. 2,635,354, dated April 21, 1953 referred to before. The structure of said valves is no part of my present invention so need not herein be shown or described in de tail.

The supply of electric power to the operative components of the clothes drier shown as being enclosed in a diagrammatic box D is eifected through a pair of conductors 26 and 27.

An indicator light 35 is also shown as: being connected in the circuit through a terminal 39 of a flame detector switch 40, and lighting when a contact arm 41 of the flame detector switch moves into position to complete a circuit through a contact 43 of said switch, which is hereinafter referred to as the hot contact thereof. The indicator light 35 thus indicates when the main burner valve is on.

A conductor 44 leads from the contact 43 of the flame detecting switch 40 and is connected with the coil 23 of the solenoid for operating the main burner valve 15. A conductor 45 connects said coil to the contact 36 of the timer switch 34. An adjustable thermostat 47, which may be manually set to control the drier temperature is connected in the conductor 45 to break the circuit therethrough and shut ofi the main burner valve when the temperature within the drier drum reaches the temperature for which said adjustable thermostat is set.

A primary coil 53 of the transform-er 21 is initially connected in the energizing circuit through the conductor 51 and a contact 54 of the flame detecting switch 40. The connection from the cold contact 54 includes a conductor 55 leading from said cold contact and having a conductor 56 connected thereto which in turn is connected to one terminal of the coil 53. The other terminal of the coil 53 is connected with the conductor 27 through a conductor 57, contacts 59 of a warp switch 60 and a conductor 61, connected to the conductor 37. A heater coil 63 is shown as being connected in parallel with the primary 53 of the transformer 21 and as being energized upon the energizing of said primary, to open the contacts of the warp switch 59 by resistor heat after a predetermined time interval, which may be from 3 to 5 minutes at normal voltages.

The coil 12 of the solenoid for opening the master valve 11 is shown as being energized through the cold Y contact 54 of the flame detector switch 40 by a conductor 63a, connected with a contact 64 of a shut-off switch 65. The shut-01f switch 65 may be a well known form of quick acting shut-off switch having a contact arm 66 normally biased to complete a circuit from the contact 64 to the coil 12. The quick shut-off switch 65 is shown as being moved to complete a circuit through a contact 67 connected with the conductor 51 by operation of an armature 69 for the solenoid operating the valve 11,

upon the energization of the coil 12 and opening of the master valve 11. Thus when the flame detector switch 40 is in position to complete a circuit through its contact arm 41 and cold contact 54, the coil 12 will be energized. This will immediately break the circuit through the contact 64 and complete a circuit to a contact 67, holding said coil energized through the conductor 51. The circuit from the coil 12 to conductors 61 and 27 is shown as comprising a conductor 70 connected with the conductor 57, the contacts 59 of the warp switch 60 when said warp switch is in a closed position, and the timer switch 34.

The warp switch 60 is provided to deenergize the coil '12 for the solenoid of the master supply valve 11 and shut off the supply of gas to the pilot burner 17 and main burner valve in the event the flame detector switch should not pass from its hot to its cold position, as when said warp switch by resistor heat in a time interval which may be from three to five minutes should the switch arm 41 fail to move out of engagement with the cold contact 54 into engagement with the hot contact 43,

as by failure of the pilot to ignite, as previously mentioned. Upon opening of the circuit through the contacts 59 of the warp switch 60 by resistor heat, the conductor 55, cold contact 54 and contact arm 41 of the flame detector switch will short circuit the coil 12 from the energizing circuit and the main or master burner 11 will go off by de-energization of the coil 12. occurs, the armature 69 of the solenoid operating said master burner valve will release an arm 71 of the quick shut-oif switch 65 and said switch will move to its biased position and complete a circuit through the contact 64 and contact arm 66 thereof. When the quick shut-off switch 65 is in this position, the coil 12 can only be energized and the master valve 11 can only be open when the flame detector switch 40 is in position to complete a circuit through its contact arm 41 and cold contact 54.

In order to ignite the pilot burner 17 and the main burner 16 when the solenoid 12 has been de-energized by failure of the pilot burner to ignite and the contacts 59 'of the warp switch are maintained open by the heater coil 63, the circuit to the dryer must be opened as by opening of the switch 34, to allow the time-delay warp switch 60 to cool and close the contacts 59, after which the switch 34 may again be closed and the burner circuit is in condition to ignite the pilot burner.

The flame detector switch 46 may be of a type similar to that shown and disclosed in my joint application with 'P. E. Geldhof, Serial No. 123,018 and now Patent No.

2,635,354, dated April 21, 1953 previously mentioned, wherein the heat of the pilot flame will move the contact arm 41 into position to close a circuit through the hot contact 43 of said switch and complete a circuit from the conductor 51 to the conductors 45 and 27.

When this This will energize the coil 23 and open the main burner valve 15. Thus when the pilot burner 17 has been ignited the main burner valve 16 can only open when the heat of the flame has moved the contact arm 41 into engagement with the hot contact 43.

The instant, however, a power interruption occurs, the coils 23 and 12 will be de-energized. This will shut ofl the master valve 11 and the supply of gas to the pilot burner 17 and the main burner valve 15. It will also shut off'the main burner valve 15. De-energizing of the coil 12 will also release the quick shut-off switch 65. Said switch will then move to its biased position to complete a circuit through the contact 64 and cold contact 54 of the flame detecting switch 40 to the coil 12. When the quick shut-oflf switch 65 is in the position just men tioned., the coil 12 can only be energized through the cold contact 54 of the flame detecting switch 46. The main or master supply valve, therefore, cannot be opened to supply gas to the pilot 17 and main burner 15 until the main and pilot burners have cooled sufficient- 1y to accommodate the contact arm 41 to move from its hot to its cold position.

In operation, the contacts 59 of the warp switch 60 .are normally closed and the movable contact 41 is en gaged with the cold contact 54. When the switch 34 and the door switch 29 have been closed, the solenoid coil 12, the transformer primary 53, and the coil 63 of the timed delay or warp switch 60 will all be connected in parallel between the supply lines 27 and 51. The master gas supply valve 11 will then be opened and gas will be supplied to the pilot burner 17. Upon opening of the master gas supply valve 11, the switch arm 66 of the quick shut-off switch 65 will move into engagement with the contact 67 and hold the solenoid energized through the conductor 51. In normal operation the gas issuing from the pilot burner 17 will be ignited by the glow coil 19 and the heat of the pilot burner flame will move the movable contact arm 41 of the flame detecting switch 40 out of engagement with the cold contact 54 into engagement with the hot contact 43 of said flame detecting switch. The solenoid coil 23 of the main burner valve 41, the conductor 45, the thermostat 47, the switch 34 and conductor 27. The main burner valve 15 will then open to supply gas to the main burner 16.

If, for any reason, the pilot burner should fail to ignite, the heater coil 63 of the time-delay or warp switch 60 will open its contact 59 after a predetermined time interval. When this occurs, the solenoid coil 12 as well as the primary 53 of the transformer 21 will be de-energized and the contacts 59 will be maintained in open position.

The quick shut-off switch 65 will also be released, and the contact arm 66 thereof will move to its biased position into engagement with the contact 64. The solenoid coil 12 thereof cannot again be energized until the contact arm 41 has moved into position to engage the cold contact 54, and the contacts 59 of the warp switch 60 have been closed. In order to again ignite the burner, the switch 34 must be opened to allow the time-delay or warp switch 60 to cool and close a circuit through the contacts 59 thereof. The switch 34 may then be closed.

The solenoid coil 12 may then be energized, opening the main burner 11 and engaging the contact arm 65 with the contact 67 to maintain the solenoid coil 12 energized and the main burner valve 11 open. The main burner will then be ignited and the circuit will be re-established, as previously described.

It may be seen from the foregoing that a simplified igniter circuit for gas burners has been provided, instantaneously shutting off the supply of gas to the main burner upon a power failure and holding the supply of gas shut off until the flame detecting switch has passed to position to close a circuit through its cold contacts and turning on the supply of gas to the pilot burner only through the'cold contacts of the flame detecting switch; and holding the main burner valve closed until the pilot burner has been ignited a suflicient length of time to move the contact arm of the flame detector switch 40 to engage the contact 43 thereof and complete a circuit through the hot contacts of said switch.

It will be understood that various modifications and variations of the present invention may be effected without departing from the spirit and scope of the novel concepts thereof.

I claim as my invention:

1. A gas burner circuit comprising a main gas burner having a gas supply line connected thereto, master and main burner solenoid opearted valves in said supply line, a flame detector switch having hot and cold contacts, an energizing circuit to the solenoid of said master valve through the cold contact of said flame detector switch, an energizing circuit to the solenoid of said main burner valve through the hot contact of said flame detector switch, a main line energizing circuit connected with said flame detector switch, and the circuit from the cold contact of said flame detector switch including a shut-oil switch, biased to complete a circuit to the solenoid for said master valve through the cold contact of said flame detector switch and operated upon energization of said solenoid for said master valve, to break the circuit through said cold contact and connect said solenoid for said master valve directly to said main line energizing circuit until a power interruption, and moving to its biased position upon a power interruption and holding said solenoid for said master valve out of the energizing circuit except through the cold contact of said flame detector switch.

2. A gas burner circuit comprising a main gas burner having a gas supply line connected thereto, a master solenoid-operated valve in said supply line, a main burner solenoid-operated valve in said supply line, a pilot burner in said supply line on the supply side of said main burner valve, a flame detector switch having hot and cold contacts and moving from a position closing a circuit from a main line circuit through its cold contact to a position closing a circuit from the main line circuit through its hot contact by the presence of a pilot flame, an energizing circuit to the solenoid of said master valve through the cold contact of said flame detector switch, an energizing circuit to the solenoid of said burner valve through the hot contact of said flame detector switch, and the energizing circuit to said solenoid for said master valve including a shut-off switch biased to complete a circuit to said solenoid through the cold contact of said flame detector switch and moved by opening of said master valve to by-pass said cold contact and connect said solenoid for said master valve directly with the main line circuit upon energization of said solenoid for said master valve, and moving back to its biased position upon a power interruption.

3. In an automatic gas igniter, a gas supply line having a main burner valve therein and a master valve on the supply side of said main burner valve, for controlling the supply of gas to said main burner valve, a pilot burner on the supply side of said main burner valve and the downstream side of said master valve, individual solenoids for each of said valves energizable to open the same, an energizing circuit for said solenoids including a flame detector switch having hot and cold contacts, the hot contacts of said flame detector switch being connected to energize the solenoid for said main burner valve, a warp switch having contacts connected in series with the sole noid coil for said master valve to energize said coil when the contacts of said warp switch are closed and said flame detector switch is in position to close the circuit through its cold contacts, a heater coil energized through the cold contacts of said flame detector switch and opening said warp switch by resistor heat, to shunt said solenoid coil for said master valve out of the energizing circuit and shut oil the supply of gas upon the failure of said pilot burner to ignite, and the energizing circuit to saidsolenoid for said master valve also including a shutofl switch having two contacts, one connecting said solenoid coil with the cold contacts of flame detector switch and the other being connected directly in the energizing circuit and connecting said solenoid coil for said master valve in the energizing circuit upon the energization of said solenoid coil,,said shut-ofl switch being biased to hold said solenoid for said master valve out of the energizing circuit except through the cold contacts of said flame detecting switch whenever a power interruption occurs.

4. In a gas burner circuit, a main gas supply line, two valves connected in series in said gas supply line, one being a master valve and the other being a main burner valve and being connected in said gas supply line on the downstream side of. said master valve, a pilot burner connected in said gas supply line on the downstream side of said master valve and} the supply side of said main burner valve, individual solenoids for each of said valves, energizable to open said valves, a main line conductor and a flame detector switch connected with said main line conductor and having hot and cold contacts and a movable switch arm movable from a position in engagement with said cold contact into engagement with said hot contact to complete a circuit from said main line conductor through said hot contact to energize said solenoid for said main burner valve upon the presence of a pilot flame, a shut-off switch connected in series with the cold contact of said flame detector switch for initially energizing said solenoid for said master valve through the cold contact of said flame detector switch, said shutoff switch having two contacts, one being connected with the cold contact of said flame detector switch and the other being connected directly with said main line conductor, said shut-off switch being biased to close a circuit through the cold contact of said flame detector switch and moved by the opening of said master valve upon energization of the solenoid therefor to open the energizing circuit to said master valve through the cold contact of said flame detector switch and to maintain a holding circuit for the solenoid for said master valve through said main line conductor, said shut-off switch moving back to its biased position and deenergizing said solenoid for said master valve upon an interruption in the energizing circuit, and holding said solenoid for said master valve deenergized and maintaining said master valve closed until movement of said flame detecting switch into position to close a circuit through its cold contact.

5. In a gas burner circuit, a gas supply line, two valves connected in series in said gas supply line, one being a master valve and the other being a main burner valve, the master valve being on the supply side of said main burner valve and having a pilot burner connected therewith for igniting a main burner, individual solenoids for each of said valves energizable to open the same, a flame detector switch having hot and cold contacts and a movable switch arm engageable with the cold contact when the pilot is not lit and movable into engagement with the hot contact to close a circuit therethrough by the heat of a pilot flame, a main line conductor connected with said movable switch arm, an energizing circuit from said main line conductor to said solenoid for said master valve through said flame detector switch, the energizing circuit to said solenoid for said master valve including a quick shut-oil switch operated by actuation of said master valve and having two contacts and a contact arm connected with said solenoid for said master valve, one of said contacts being electrically connected with the cold contact of said flame detector switch to energize said solenoid for said master valve through the cold contact of said flame detector switch, the other of said contacts being connected directly with said main line conductor to energize said solenoid for said master valve directly through said main line conductor upon movement of said master valve to an open position upon energization of the solenoid therefor, and means biasing said contact arm of said shutoff switch into engagement with said one contact to close a circuit through the cold contact of said flame detector switch upon a power interruption and the deenergization of the solenoid for said master valve.

6. In a burner control system in combination, a pilot burner, a fuel control means having in serial connection with one another a normally closed inlet valve, a normally closed outlet valve, and a main burner fuel supply outlet, said fuel control means further including an outlet between said inlet and outlet valves for supplying fuel to said pilot burner, whereby said inlet valve controls the flow of fuel to both burners and said outlet valve controls the flow of fuel to the main burner only when said inlet valve is open, an electromagnetic actuator for 'said inlet valve, an electromagnetic actuator for said outlet position to a hot position in response to a flame at said 2 pilot burner, a double throw switch operatively associated with said inlet valve actuator, said double throw switch being biased to one position and being moved to its op posite position by said inlet valve actuator when it is energized, an energizing circuit for said inlet valve actuator including said double throw switch when in its biased position and said flame sensitiveswitch when in its cold position, an energizing circuit for said igniter including said flame sensitive switch when in its cold position, an energizing circuit for said outlet valve actuator including said flame sensitive switch whenin a hot position, and shunt means for maintaining an energizing circuit for said inlet valve actuator when said flame sensitive switch moves from said cold to said hot position including said double throw switch when in its opposite position.

References Cited in the file of this patent UNITED STATES PATENTS 2,269,157 Levine Jan. 6, 1942 0 2,327,690 Ackerman Aug. 24, 1943 2,456,147 Ray Dec. 14, 1948

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