US1734095A - Apparatus for controlling oil-burner pilot flames - Google Patents

Description

A. s. MANCIB 1,734,095

APPARATUS FOR CONTROLLING O IL BURNER PILOT FLAMES Nov. 5, 1929.

2 Sheets-Sheet 1 Filed Feb. 28, 192'? m R K v \k w EEaSS NOV. 5, 1929. I s, MANCIB- 1,734,095

APPARATUS FOR CONTROLLING OIL BURNER PILOT FLAMES Filed Feb. 28, 192'? Z'Sheets-Sheet 2 Patented Nov. 5, 19 29 UNITED STATES 1 .T1-:1-rr' OFFICE I ALVIN S. CIB, OF SOMERVILLE, MASSACHUSETTS, ASSIGNOR TO HOWARD O. JONES, OF WATERTOWN, MASSACHUSETTS, AND EVERETT W. MANTER, OF TAUNTON, MASSACHUSETTS, COPARTNERS, DOING BUSINESSAS JONES & MAN TERI! OF BOSTON,

MASSACHUSETTS APPARATUS FOR CONTROLLING OIL-BURNER PILOT FLAMES Application filed February 28, 1927. Serial No. 171,559.

The object of the present invention is to provide an apparatus for thermostatically controlling the pilot flame of oil burners and,

' specifically, to provide means whereby the has been raised to the proper temperature flow of gas through the pilot flame valve is increased and the said flame enlarged when the starting switch is thrown, the oil-burner motor started at the proper interval thereafter and then the flow of gas through the pilot flame reduced to normal amount after the vaporized oil has been ignited.

' With the foregoing objects in view, my invention comprises an electrically-controlled pilot flame valve positioned with respect to its seat to permit a relatively small amount of gas to flow therethrough, and a circuit including the magnet of sa d valve whereby, upon the closure of the main switch, said valve is .raised from its seat, thereby permitting a relatively large amount of gas to flow; and a thermo-statically controlled switch "for opening the circuit of said valve and permitting the latter to resume its normal position after the oil has been ignited.

It comprises also a thermo-statically-controlled switch for closing the circuit of the oil-burner motor after the heating chamber .Jy the pilot flame, and a relay for holding said switch closed after the thermostat heating coil has been short-circuited; and it further .comprises other novel devices and circuit ar- Fig. 3 is a longitudinal section of one form of electromagnetically-controlled valve that may be employed.

Fig. 4 is a diagram showing the control by a thermostatic switch.

In the particular drawings selected for more fully disclosing the principle of my invention 1, 2 represent the mainline terminals arranged to be connected to the usual electric lighting circuit; 3, 4 are the terminals of the oil-burner motor; and 5, 6 are the terminals of the electromagnetically-controlled pilot-flame valve; said terminals being shown as binding posts mounted on the panel 7 to which are secured in any suitable manner heating coils 8, 9, each of which may have approximately 800 ohms resistance. In the present instance, the metallic cylinders 11, 12 which support the coils, are closed at their lower ends by the plugs 13, 14, each provided with a pair of upstanding cars 15, between which are pinned at their lower ends suitable oppositely-disposed bi-metal strips 16, 17, said strips being so arranged that when heated they will bend in opposite directions. Se-- cured to the upper ends of said strips, respectively, are the metallic plates 19, 20, the upper ends of which plates are connected together in any suitable manner by the insulating member 21 which, in the present instance, is shown "by the spring 28 which is coiled around the stud 29 on which said switch is mounted. The post 30 is also mounted on the panel and carries an adjustable contact screw 31 which may be held in adjusted position by the screw 32, the end of said post being shown in the present instance as split longitudinally.

A relay magnet 33 is suitably secured to the panel and provided with an armature 34 pivoted at 35 and carrying the bifurcated spring contact maker 36, the two arms 37, 38 of which are arranged to co-operate with the contact studs 39, 40, respectively. A retractile spring connected between the panel and the screw 41 adjustable by the nut 42 normally holds the arms 37, 38 away from their co-operating studs.

It is to be understood of course that the and waste of oil.

sentations of the same in Fig. 2, 43 represents a switch for connecting the terminals 1 and 2 to the lighting cificui't 44. Upon such connec-, tion being made, the current passes from the binding post 1 to the gas valve magnet 45 by way of the point a, binding-post 6, thence through said magnet to binding-post 5, to the contact member 27, its co-operating switch blade 26 and thence back to the main line by way of the binding-post, 2. Upon the resulting energization of said magnet 45, the flow of gas through the pilot flame valve is increased and the flame enlarged, and said flame is kept in this condition a suitable time, for example, five minutes, to thoroughly heat the combustion chamber and its associated parts, so that-the oil pumped into said chamber by the usual motor 46, with which certain oil-burner systems are provided, will immediately ignite, thereby preventing flooding While any suitable electromagneticallycontrolled pilot flame valve may be used, I

have shown in Fig. 3, and indicated in Fig. 1,

avalve which has been found in practice to be suitable for the purpose, such valve consisting of a block 47 provided with a longitudinal bore ,48 in one end of which .is

threaded a regulating pin 49 and the opposite end of which is enlarged to receive the sleeve 5.0 Which houses the valve member 51 of magnetic material and the spring 52 whereby said valve is maintained normally on its seat 53 so shaped that when said valve is seated, there will be a small by-pass around the same for the flow of gas to maintain the pilot flame. Said block is bored transversely at 54 for attachment of the gas inlet pipe and also at 55 for attachment of the outlet pipe leading to the pilot flame. When the valve 51 is raised by the energi zation of the magnet 45, the flow, of gas through the inlet 54and outlet 55 will be substantially increased and the pilot flame enlarged for the purpose above set forth:

It is to be understood, however, that the particular form of gas valve herein illustrated constitutes no part of my invention. Simultaneously with the closure of the switch 43 and the energization of the gas valve magnet 45 by way of the path above indicated, current flows fromthebinding-post 1 to the point a, through the heating coil 8 to the point 5, and thence through the motor 46 by way of the binding-post 4 and then back to the main line by way of the binding posts 8 and 2. I Y

The heating coil 8 being of high resistan e, r

such for example as 800 ohms, the motor will not operate. It will be noted that said motor constitutes a short circuit around the heating coil 9, one terminal b of said coil 9 being connected to the terminal 4 of the motor, and the other terminal 0 thereof being connected to the terminal 2. Current therefore will not flow through the coil 9 'while the motor is at rest. In like manner, the said motor, while stationary, constitutes a short circuit around the winding 56 of the relay 33, one terminal 2) of'said winding being connectedto the terminal 4 of said motor, and the other terminal at to the terminal 3 of said motor by way of the binding-post 2.

Current,,therefore, will not flow through said relay while the motor is stationary.

After the gas valve has been actuated a sufficient length of time to raise the combustion chamber to the desired temperature, for eX- ample, about three minutes, the coil 8 has raised the bi-metal strip 16 to the necessary temperature to'cause the same to move to the right and thereby bring the plate 19 into electrical contact with the post 31, whereupon the coil 8 is short-circuited, the coil 9 is effectively connected to the main circuit, the motor is operated, and the relay 33 is energized all in the'followingmanner: The lower en of the coil 8 is electrically connected by the jumper 57 to the strip 16 in any suitable manner, such as indicated at Fig. 2, by grounding the short wire 57 to the metallic tube 11 which, through the plug-'13, is in electrical connection with the strip 16. Therefore, when the plate 19 makes contact with the post 31, the coil 8 is short-circuited, thereby cutting out of the motor circuit the resistance of said coil, so that the motor circuit will now be closed through the following path, viz, binding-post 1, a, e, strip 16, plate 19, post 31, I), post 4, motor 46, post 3, main-line terminal 2.

The back electromotive force of said motor will break the short-circuit placed, as aforesaid, by said motor when stationary around the coil 9 and relay winding 56, so that the current will now flow through the heating coil 9 by the following path, viz, main-line terminal 1, a, e, strip 16, plate 19, post 31, b, coil 9, and thence to main-line terminal 2 by way of c, f and d. Simultaneously with the effective connection of the coil 9 to the energizing circuit, there will be a flow of current through. the relay winding 56 from the post 1 to a, e, strip 16, post 31 b, b, conductor 58, winding 56 and thence back to the post 2 by way of d.

The energlzation of the relay closes a motor-holding circuit, thereby rendering the circuit of the motor independent of the strip 16, so thatafter thecoil 8 coolsand plate 19 breaks contact with post 3 1,.the motor will the heating coil 8.

r The gas valve\wi1l remain open for a suitable length of time after the motor has started, say, for example, two or three minutes, or five or six minutes after said valve was openedin the first instance. The de-energization of the gas valve magnet 45 is effected through the cooling of the coil 8 and the heat ing of the coil 9 inthe following manner, viz., about two or three minutes after the motor has started and the coil 9 is effectively connectedtothe energizingcircuit in the man- -'ner above pointed out, the b-i-metal strip 17 has moved suificiently to the left to overcome the movement to the right of the strip 16 which, as soon as the coil 8 becameshort-circuited by the contact of the plate 19 with the post 31, began to cool, and slowly move to the left. The strips being connected by the rod 21, move together, and it has been found that while the strip 17 is not absolutely essential, a much more positive action and better timing is secured by employing said strip acting in opposition to the strip 16, the reason for this being that the strip 8 cools rather slowly, and its movement to the left to regain its normal centralposition is slower than the movement in the same direction of the strip 17 when its temperature is raised. As the thermostatic system moves to the left, the finger 25 causes the gas valve switch member 26 to break contact with its post 27, whereupon the magnet is de-energized and the valve 51 is forced on its seat by the spring 52, thereby reducing the pilot flame to its normal size.

It will be noted that after the cycle of operations'above cited has been effected, the

current will not again flow through the heating coil 8 for the reason that the conducting plate 36 carried by the relay armature has put a shunt around said coil, the terminal 6 of said coil being connected to the post 39 and the terminal e to the post 40, said posts being conductively connected, when the armature.

34 is attracted, through the metallic member 36. Upon the re-opening of the main switch 43 the parts resume their normal positions and the cycle .of bperations above set forth must be repeated before the oil burner can again be started.

It will be understood of course that systems such as disclosed herein are usually actuated by the room thermostat indicated at T in Fig. 4, by means of which thermostat the oil burner is started when the room temperature falls to a given degree, and stopped when it rises to the temperature to which the pilot-flame valve, a motor,

times broken accidentally.

It will be obvious that the closure of the circuit of the thermostat T will result in the identical 'operations performed when the switch 43 is closed. If the switch 43 be opened or the connection of the apparatus to the main line be broken by tampering with the thermostat T, the circuit of the relay magnet 33 instantly is broken, and the motor 46 comes to rest, the retractile spring governing the armature 34 and connected between the latter and the pin 41, being fairly strong. As soon as the connection of the system to the main line is broken and the motor comes to rest as aforesaid, there is of course no further pumping of fuel to the oil burner. When the connection of the system to the main line is again made, either by closing the switch 43 or the circuit of the thermostat T, the cycle of operations above set forth must be repeated before the oil is again ignited,in other words, the pilot flame is enlarged to the proper degree and the combustion chamber Having thus described an illustrative embodiment of my invention and a circuit arrangement in which the same may be employed, what I claim and desire to secure by Letters Patent is 1. An apparatus of the class described comprising in combination, a switch, a pilot-flame valve, an electromagnet for actuating the same, a source'of electricalenergy, a circuit connecting said electromagnet, switch and source, two heating coils, means for normally energizing one of said coils upon closure of the circuit, two bi-metal strips, each mounted at one end within one of said coils, means connecting the other ends of said strips together and to one member of said switch, said bi-metal strips being constructed and arranged to move in opposite directions when heated, and means for short-circuiting'the energized coil and simultaneously energizing the other coil.

.2. An apparatus of the class described, a a pair of heating coils, a bi-metal strip mounted in each of said coils, a circuit for said motor controlled by one of said bi-metal strips means whereb one of said heating coils is short-circuited ruary, 1927;

after the strip enclosed therein has reached a certain temperature, connections whereby the second heating coil is energized upon the short-circuiting of the first, and means for preventing the energiz'ation of the first coil after the energization of the second.

In testimony whereof, I have hereunto subscribed my name this 21st day of Feb- I ALVIN s. MANoIB.

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