US1850437A - Electric control system - Google Patents

Description

March 22, 1932. w. w. WILLIAMS ELECTRIC CONTROL SYSTEM Filed July 31, 1950 a M H Y L M W n O. N TW R N 0 W yn mw L. a m

Patented Mar. 1932 UNITED STATES PATENT OFFICE WALTER w. WILLIAMS, 0] BLOOmGTON, ILLINOIS, ASSIGNOB 'I'O WILLIAMS OIL-O- IATIG HEATING- CORPORATION, IILINOIB Application filed July 81,

This invention relates to improvements in the electric control system for electrically operated and actuated domestic fluid fuel controlled either by the commercial circuit,

or one dependent upon it, including a room thermostat which may be set at the desired temperature of the ,room or portion of the building in which it is located and will act to close the circuit to the burner motor when the temperature descends below and open the circuit to theburner motor when the temperature reaches or extends above the desired degree. Fluid fuel burners of this type usually include an electric ignition system as well as such safety devices as may be required by the Fire Underwriters. The ignition system usually includes a transformer with an ignition 7 switch for closing the circuit to the trans burner mechanism to ignite the 7 after breaking the circuit to the transformer.

former and causing an electric spark when the fluid fuel is initially su plied to the uel and there- The safet devices usually include a boiler ,control w ich is normally closed and will act to breair the circuit when the degree of tempreaches the perature or pressure within the boiler aptric switch responsive to presence or absence of combustion'within the heater, which if combustion occurs will permit the burner to operate and if combustion fails to occur will cause the burner to cease operating.

It is an object of this invention to provide a. system such as above described for controlling the operation of a domestic fluid fuel burner which includes an ignition switch I which is normally ofin when the burner is idle and which will 21; redetermined time after the operation o t e automatically closed urner motor is initiated and to include in the circuit between the source and burner motor an additional safety device which will break the circuit to the motor in a-predetermined time the motor does not start the circuit to the danger limit, as well as an elecas including a casing mostat T, ,0 with a' boiler ,control B, of commercial de- Oll' BLOOMINGTON, ELIHOIS,"A CORPORATION 01' ELECTRIC CONTROL SYSTEM 1930. Serial No. 472,137.

after it opens said safety device will break I motor; and which upon normal operation of the burner and the closing of the switch responsive to combustion conditions will be shunted out and the burner will continue to operate until the room thermostat opens the motor circuit, but if the burner flame becomes extinguished for any reason after ignition the switch responsive to combustion conditions will open and the full I strength of the commercial current passing through said safety device will cause it to break the motor circuit.

With these and other objects in view refer-' ence is made to the accompanying sheet of drawing which illustrates a preferred form of this invention with the understanding that minor detail changes may be made without departing from the scope thereof.

The drawing is a diagrammatical view of this improved system as a plied to a com mercial type of domestic fluid fuel burner mechanism installed in connection with a commercial type of domestic heater.

The fluid fuel burner mechanism is shown 1 supported upon a standard 2 mounting an electric motor operating a fanwithin under pressure through a draft pipe 4 opening through the wall 5 of the domestic heater into the combustion chamber 6 thereof. As is customary in this type of burner fluid fuel is supplied through a uel pipe 7 and is discharged through a nozzle 8 into the combustion chamber 6 where it is ignited by a a housing 3 to direct air spark jumping between electrodes 9 in circuit with the transformer 10.

The wiring diagram-includes a room thercommercial, design, in circuit sign,- a switch responsive to combustion condition S, of commercial design, and an ignition switch I. As

above stated certain types of commercial burners include in their c0'n-' trol systems an ignition switch which is nor mally open and which is closed for a predetermined time by the energization of the burner motor. In this particular type illus-' trated the ignition switch I is shown in the open position. The burner motor is mounted in a casing supported 'on trunnions 11 rotatable upon bearings in the burner casing. One of these trunnions 11 is providedwith a connection 12 to the ignition switch carrier plate 13 whereby the force of reaction when the motor is energized imparts a rotative movement to the trunnion 11, causing the carrier plate 13 to close the ignition switch and thereafter release the carrier plate and allowing the dash pot 11L to return the ignition switch to open position. The applicant has seen fit to illustrate the embodiment of this invention in connection with the above described commercial ignition switch oper ating mechanism more fully illustrated and described in United States Patent 1,783,405 dated December 2, 1930. However, understood that this invention is not limited to this particular commercial construction as any means operated upon energizing the burner motor to actuate the ignition switch to first close and then open, such as the pressure created by a fan or a pump operated by the motor, may be employed.

This invention contemplates the insertion in the control. circuit of a thermal circuit breaker C, of commercial design, which may be adjusted so that when the commercial current has passed through the thermal member thereof for a predetermined time the said member will release a spring pressed switch to break the circuit and which switch maybe reset manually and be held in closed position by the cooled thermal member. This circuit breaker G is placed in the circuit to normally conduct. the incoming commercial current about the switch S to the motor and when the ignition I switch is closed to shunt out the secondary circuit breaker C.

In accordance with this invention when the room thermostat calls for heat byclosing, the incoming current from the commercial line follows through the wire 15, passing through the closed thermostat T, the normally closed boiler control B, through wire 16, circuit breaker C to the motor, and back by the way of wire 17 to the source, whereby the circuit to the motor is completed and should the motor through any defect therein fail to operate, the circuit breaker will automatically break the circuit after a predetermined time, thereby preventing further inf jury by the continued passage of the current through the motor, The normal operation of the motor when started closes the ignition switch I which is a three terminal switch-of the mercury tubefltype, as shown, whereby a it is/to be circuit is completed by a wire 18 from-wire 15, through the closed ignition switch I and by wire 19 through the transformer '10 back to wire 17, and at the same time a cir'- cuit is closed by wire 18- fromthe wire 15 through'the ignition switch I, through wire 20 and through wire 16 to the motor and then back to wire 17. This allows the motor to continue to operate while reducing the strength of the current passing through the circuit breaker and at the same time energizes the ignition transformer. Should the fluid fuel fail to ignite, as the ignition switch is normally opened after a predetermined time, thereafter the 'full strength of the current Will pass through the circuit breaker and cause it to open the circuit to the motor. When the fluid fuel is ignited, the switch S, normally open and responsive to combustion, closes a circuit, through wire 21 to wire 16 on each side of the circuit breaker C, thereby shunting out the circuit breaker and connecting the motor circuit directly to the commercial line and causing the motor to operate as long as the switch S, boiler control B and room thermostat T remain closed. What I claim is:

1. An electric control system for an electrically operated and actuated domestic fluid fuel burner including a burner motor in a motor circuit, an ignition device in an ignition circuit having an ignition switch therein normally open, means actuated upon m1- .tiating the operation of the motor to close the ignition switch, and a circuit breaker in the motor circuit adapted to break the motor circuit upon failure of the motor to operate, and means to shunt out the circuit break 81 upon the closing of the ignition switch.

2. An electric control'system for an electrically operated and actuated domestic fluid fuel burner including a burner motor in a motor circuit, an ignition device in an ignition circuit having an ignition switch therein normally open, means actuated upon initiating the operation of the motor to close the i nition switch for a predetermined time and fliereafter'open the ignition switch, a circuit breaker in the motor circuit, and a shunt circuit including the ignition switch for shunting out the circuit breaker while the igcuit breaker in the motor circuit, and a shunt circuit including the ignition switch for shunting out the circuit breaker while the ignition switch is closed, and an additional shunt circuit including a normally open switch responsive to combustion conditions adapted to close upon ignition of the fuel and shunt out the circuit breaker before the opening of the ignition switch.

4. An electric control system for an electrically operated and actuated domestic fluid fuel burner including a burner motor in a motor circuit, an ignition device in an ignition circuit having an ignition switch therein normally open, means actuated upon initiating the operation of the motor to close the ignition switch for a predetermined time and thereafter open the ignition switch, a circuit breaker in the motor circuit, two shunt circuits each adapted to shunt out the circuit breaker, one shunt circuit including the ignition switch, a normally open switch in the other shunt circuit adapted to close upon establishment of combustion, whereby the closing of the motor circuit and initiation of the operation of the motor shunts out the circuit breaker while the ignition switch is closed and ignition of the fuel shunts out the circuit breaker before the ignition switch is opened.

5. An electric control system for an electrically operated and actuated domestic fluid fuel burner including a burner motor in a motor circuit, av circuit breaker in the motor circuit, two normally open shunt circuits each adapted to shunt out the circuit breaker, means actuated by the operation of the motor to close one shunt circuit for a pre-determined time only and means actuated upon establishment of combustion to close the other shunt circuit.

6. An electric control system for an electrically operated and actuated domestic fluid fuel burner including a burner motor in a motor circuit, a circuitcbreaker in the motor circuit, two normally open circuits each adapted to shunt out the circuit breaker, means actuated by the operation of the motor to close one shunt circuit for a predetermined time and thereafter open the said shunt circut, and means actuated upon establishment of combustion to close the other shunt circuit.

7. An electric control system for an electrically operated and actuated domestic fluid fuel burner including a burner motor in a motor circuit, a circuit breaker in the motor circuit, two normally open circuits each adapted to shunt out the circuit breaker,

- means actuated by the operation of the motor to close one shunt circuit for a predetermined time and thereafter open the said shunt circult, and means actuated upon establishment of combustion to close the other shunt circuit before the first shunt circuit is opened.

WALTER W. WILLEAMS.

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