Patent GB-292257-A (GB)
Title: Improvements in oil burning devices
IPC: F23D11/36
Filed: 1927-03-18
Abstract: 292,257. Marks, E. C. R., (Williams Oil-o-Matic Heating Corporation). March 18, 1927. Electrically controlling fuel and air supplies; spray burners; liquid fuel supply.-A liquid fuel burning apparatus for a domestic heating system is provided with a safety control device operating in the event of non-ignition of the fuel or cessation of combustion comprising an electric heating device arranged in a circuit including a spring switch, which is closed manually when the apparatus is set for operation, and a. break, which is closed when a heat-sensitive element arranged near to the burner flame is cold, the electric heating device being disposed in proximity to another heat-sensitive element, which, on prolonged heating, closes a circuit through an electromagnet which operates the spring switch and stops the fuel projecting mechanism. The burner apparatus comprises an electric motor 12 operating a metering pump 15 to supply fuel through an atomizing chamber 14 to a burner nozzle 27 and a fan 23 to supply air through a housing 25 to the burner nozzle 27. The air is whirled bv vanes 28 in a direction opposite to that of the fuel issuing from the nozzle. A counterweighted closure member 29 opened by the air blast against the resistance of a dash-pot 32 is pivoted in the housing 25. The apparatus is put into operation on closing the main switch 82 and moving the armature 51 of an electromagnet 50 to the position shown in Fig. 2 so as to complete at 56 a connection from one terminal on the low tension side of a transformer C to the movable, arm 77 of the room thermostat A. The armature 51 which forms the spring switch referred to above consists of two parts connected by a spring 52 and pivoted to a terminal 53. When the room temperature falls to its lower limit, the movable arm 77 engages a contact 79 and completes the low tension circuit from the transformer through an electromagnet 63 thereby moving a pivoted armature 64 to complete at 70, 71 the high tension circuit to the motor 12. On the motor starting the pressure in the atomizing chamber 14 is communicated through a pipe 21 to a, pressure diaphragm 20 which operates the fuel control valve 19 and also to diaphragm 34 which lifts a lever 35 against the resistance of a dashpot 39. During its movement, the lever 35 opens for a time a valve 31<1> allowing gas to pass to a pilot burner 36 adjacent the nozzle 27 and also completes temporarily at 36<1> the primary circuit of a spark coil D for causing sparking between a rod 37 and the pilot burner to ignite the gas at the pilot burner and thereby to effect the ignition of the main burner. On the room temperature rising to its upper limit, the arm 77 engages a contact 78 and completes the low tension circuit from the transformer C through an electromagnet 62 thereby moving the armature 64 to break at 70, 71 the motor circuit and stop the fuel projecting mechanism. When. the armature 64 moves to complete the circuit to the motor 12, it also completes at 66, 68, a circuit including a bimetallic strip 38 at the burner nozzle and a coil 108 about an asbestos strip 49 on the spark coil D. If ignition of the burner is effected, the heat of the flame causes the strip 38 to bend and so breaks this circuit, but if ignition is not effected or the burner flame becomes extinguished, the heat generated at the coil 108 causes a bimetalliic strip 47 to bend and close at 46 a circuit from the transformer through the electromagnet 50, a binding post 58, and the armature 51. The electromagnet 50 then causes the armature to move into a position in which its own circuit is broken at the binding post 58 and it makes at 55 the circuit through the electromagnet 62 thereby stopping the fuelprojecting mechanism until the armature 51 is manually reset.