US1673404A - Controlling means for burners - Google Patents

Description

June 12, 1928.

O. E. D'ARCHE CONTROLLING MEANS FOR BURNERS Patented .une- 12, 1928.

'UNITED' A,STATES 1,673,404 PATENT, OFFICE.

. OSWALD E. '.DARCHE,v OF WEST HARTFORD, CONNECTICUT, ASSIGNOR TO THE HART MANUFACTURING COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

CONTROLLING MEANS FOR BURNERS.

Application filed May v13, 1925-. Serial No. 30,074.

This invention relates generally to burners or heating plants, and has particular reference to means for controlling the same. As an instance of one use toWhich the improvements forming the subject matter of this invention maybe applied, reference may be had to an oil burner of the type wherein a mixture of air and oil is forced, under pressure, into a combustion chamber. While my invention is particularly applicable to such use, I wish it to be understood that it is not limited thereto, the present showin being by way of exempliication only, an the invention being susceptible of various modifications and changes in construction, arrangement and application. It has been proposed to provide oil and other types of burners with gas pilot lights, but pilot lights of this sort are open to many objections, particularly in that there is an element of danger in their use. It has also been proposed to employ, in connection with an oil burner, an igniting device having the form of an electrical unit, such as a spark plug or an element heated to incandescence by a current of electricity, but such arrangements have not met with the approval ofthe underwriters because Spark plugs are not reliable and, in the case of incandescent heating elements, these elements are quickly burned out by the heat generated within the fire pot or chamber in which the elements are located.

^ The aim of the present invention is to provide an improved controlling mechanism for burners having various features of novelty and advantage and wherein the above'and other objections tovigniting devices, as heretofore made and operated, are eliminated.

In accordance with the present illustrative disclosure of the embodiment, the arrangement is such that the igniting device, which is preferably in the form of an electrical element adapted vto be `heated to incandescence, is automatically -moved into and. out

i of igniting relation'to the burner so that damage to', and burning out of, the igniting `element is guarded against. By preference, the igniting element is raised into igniting relation to the burner before the burner is vthrown .into operation so as to insure that the igniting vdevice is in proper position before the fuel, such as oil or gas, Ais supplled to the burner. The igniting element is .with- A further object of the invention is to i y provide acontrolling means of the character described which may be very economically manufactured and easily installed, and which is sure and effective in operation.

A further object of thel invention is to provide an improved mercury switch having various features of novelty and advantage.

l Other objects will be in art obvious and 1n part pointed out more 1n detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction herein-` after set forth, and the scope of the applica- Vtion of which will be indicatedin the appended claims.

In the accompanying drawings, wherein I have show-n, more or less dlagrammatically, one of the many embodiments which .the present invention may take;

incorporated in, a heating plant or heater of any suitable construction or type, but, in the present instance, they are shown as being applied to an voil burner having a fire pot or combustion chamber 20; a blower or air pump 2l. connected'to the combustion chamber by a pipe 22; a motor 23 for driving the blower; and a nozzle 24in the discharge end of the pipe 22; oilbeing fed to this nozzle througha'pipe 25.

The pilot or igniting element may be of any suitable shape and kconstructed of any i suitable material, but, by preference, it is in the form of a resistance element which will.

1 flange or rib 30 arising about the edge of the openinnf 28. The flange 30 serves the purpose olfj preventing any oil which may collect in the bottom of the fire pan from fiowing down through the hole 28, and the cap 29, when in the position shown in Fig. 3, serves the purpose of closing the opening 23 and protecting the igniting element.

The means for moving the pilot element into and out of operative igniting position may be of any suitable construction and may be, in whole or in part, mechanically, electrically, or otherwise operated. By way of example, I have shown, in the present instance, a solenoid 33 having an armature 34 connected by a link 35 to lazy tongs 36 connected at their opposite ends to the frame k27 and a bracket 37 below or depending from the fire pot. It may be assumed that, when the solenoid 33 is energized, the armature 34 is drawn to the right, referring .to Fig. 3, whereupon the lazy tongs are extended to raise the pilot element into operative relation to the nozzle 24, and the pilot element is held in this position until the solenoid is de-energized, whereupon the armature 34 will move to the left and the pilotvelement will move down to the position shown in Fig. 3.

The controlling means for the burner and igniting device may be varied to suit requirements and is susceptible of various embodiments. This controlling means may include a mercury switch A having a tube 40 provided at one end with a pair of contacts 41 located in a circuit which includes the motor 23. The tube 40, at its other end, carries a pair of contacts 42 which are in series with a thermostatic switch B. the iguiting element 26 and the solenoid 33. The tube 40 is carried by a bracket or clip 43 fixed to a shaft or rotatable pin 44 mounted in a suitable bearing, such as may be provided in a post 45 arising from a base 46. In accordance with the present invention, I provide the switch A with means for preventing all of the mercury from prematurely flowing from one end of the tube to the other end when the tube reaches a substantially horizontal position. This means is herein shown as taking the form of a barrier, dam or hump 47 in the bottom of the tube intermediate its ends and extending up into the tube. This hump may be formed by making a curve in th/e bottom of the tube, as shown most clearly in Figs, 2 and 3. With this construction, it will be seen that, when the tube reaches a substantially horizontal position, mercury will be retained at both ends of the tube so that neither pair of the contacts 41 or 42 can be prematurely uncovered.

The means for operating the mercury switch A is of such construction that current is thrown onto the pilot element and the latter is raised into operative relation to the burner or nozzle 24 a predetermined perlod o time before the motor 23 is thrown on, and the pilot element is lowered a predetermined period of time after the burner is in operation. These results may be obtained in various ways, but I have herein shown, by way of exemplification, the following arrangement: Provided on one end of the shaft 44, to which the mercury switch is fixed, is an eccentric pin 50 adapted to be engaged by the turned over end or arm 51 of a pin 52 to which is connected one end of a torsional or thermostatic member 53 adapted to be heated by' an electrical heater, such as a resistance rod 54. The pin 52 may he rotatably mounted in a post 55. One end of thc torsional member 53, which is preferably in the form of a helix, may be fixed to a post 56. The heating unit 54 is in series with the switch constituting the contacts 42 and with the pilot element 26.

The mercury switch A is normally urged or rocked into an inclined position in which the contacts 42 are immersed. To this end, the bracket or clip 43 may be provided with an arm 60 carrying an adjustable weight 61. Vhen the torsional element 53 is heated, it is adapted to very slowly turn the pin 52 in such a direction that the mercury switch is rocked to a position in which the contacts 41 are immersed. For the purpose of holding the switch in this latter position, after the circuit through the heating unit 54 is broken, there may be provided on the shaft 44 a cam 62 having a tooth 63. Adapted to cooperate with this cam is the armature 64 of a solenoid 65 which is in series with the thermostatic switch B. When the solenoid is energized, the armature 64 is advanced towards the cam, and when the solenoid is deenergized, the armature is withdrawn from the cam, as by means of a spring 66. The mercury switch A and the parts associated therewith are, of course, primarily under the control of a suitable ,instrumentality which is to be affected by the heating effects of the heating plant. For example, this instrumen tality or regulator may be in the form of the thermostatic switch B located in a room, the temperature of which is to be regulated. The switch B may consist of a thermostatic bar adapted to flex into and out of engagement with a contact 68.

The operation of my improved arran e' ment is briefly as follows: Assuming that t e temperature of the room, within which the thermostatic switch B is located, is at or above the desired degree, and, in which case the burner would be off the parts will have the positions shown by full lines in Fig. 3. Assuming now that the temperature of the room falls below a redetermined degree, the thermostatic swltch B will close, whereupon a current will flow through the contacts 42, the heating unit 54,. the pilot element 26, and the solenoid 33, resulting in the unit 54 and pilot element being heated and the raising of the latter to igniting position. At the same time, the solenoid is energized, whereupon the armature 64 is advanced to bear against the pel'ipher of the cam 62. The heating unit 54 will eat the torsional member 53 with the result that the pin 52 will be rotated in a direction to rock the shaft 44. l/Vhen the mercury switch is brought to substant-ially horizontal position, some of the mercury will flow over the barrier 47 thereby closing the contacts 41 and energizing the motor 23, resulting in a discharge of air and fuel into the fire pot. It will be understood that the switch B is slowly turned so that the current is thrown onto the pilot element 26 and the solenoid 33 is energized an appreciableiperiod of time before the motor is thrown on, such being of advantage as it insures that the pilot elel ment is heated to incandescence and is in raised position before the fuel is discharged into the frebox. After the mercury switch passes its horizontal position and reaches that shown in Fig. 2, the contacts 42 are uncovered, whereupon the current, through the heating unit 54, solenoid 33 and pilot element 267 is broken, with the results that the pilot element is lowered to the position shown in Fig. 3, the pilot element is no longer heated, and the torsional member 53 will cool oft'. Before the member 53 cools off, however, the armature 64 will have engaged behind the abutment or tooth 63 of the cam 62, `thereby holding the mercury switch in the extreme position' shown in Fig. 2. It will 'b observed that there is an appreciable delay between the time the mercury closes the circuit between the switch contacts 41, and the time the circuit, through the contacts 42, is broken, which means that the pilot element is not rendered inoperative until after the burner has been on for a predetermined period of time', thus insuring against failure of ignition of the fuel discharged into the irebox. Now, when the temperature within the room to be controlled rises about a predetermined degree, the thermostatic switch B will open, thereby breaking the current through thesolenoid 65, with the result that the spring 66 will disengage thearmature 64 from the cam 62 permitting the weight 61 to move the mercury switch to the position shown in Fig. 3, and in which position the circuit between the contacts 4l is opened. As these contacts are opened, the motor is thrown out of operation. It willt'urther be observed that', in the event the igniter should be out of order or the element 26 should be burned out, the motor 23 will not be thrown into operation when the thermostatic switch B closes, because no current will flow through the heating unit 54 and, therefore, the mercury switch A is not moved from its normal position shown in Fig. 3.. Thus, over-flooding of the burner, together with the resultant nuisance and danger of fire, is avoided.

Asl many changes could be made in theabove construction and many apparently widely different embodiments of this invention could be made without departin from the scope thereof, it is intended that a l matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that (the language usedin the following claims is in tended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.`

I claim as my invention:

1. In combination, an oil burner having a motor, an electrical resistance unit constituting igniting means and arranged to be moved into and out of igniting position, operating means for so moving said unit, and switch means for controlling said motor, operat-ing means and unit, said switch means constituting a pivoted tube having at each end a pair of contacts, one pair being Vin series with said motor and the other pair in series with said operating means and unit.

2. In combinatlon, a burner having a molos tor, an igniting device comprising an elecl trlcal reslstance unit, operating means for moving sa'id'unit into and out of igniting position, switch means including a pair of contacts in series with said motor, a pair of contacts 1n series with said operating means and unit, and circult closing means for said contacts; and athermostatic device controlling said switch means.

3. In comblnatlon, a. burner havlngl a motor, a-resistance element constituting a piiot device and arranged to be moved into and out of igniting osition, operating means for so moving saidJ resistance element, a switch having a pair of contacts in series with saidy motor and a pair of contacts in series with said operating means and resistance element, a thermostatic 'device in series with said last mentioned contacts, actuating means for said switch, means for heating said actuating means and in series with said resistance element, and means controlled by said thermostatic means for temporarily holding said switch in motor Contact closing position.

4. In comblnation, a burner having a fire pot provided with an opening having a fiange extending into the fire pot, an igniting device mounted for movement in said opening and having an electrical resistance element, and a cap movable with said element and adapted to engage said flange and close said opening when said element is in withdrawn position.

5. In a system for automatically controlling oil burners, an oil burner having an electric motor, an electric resistance element adapted to be heated to ineandencence and mounted for movement into and out of igniting relation to said burner, electrical operating means for automatically--effecting movement of said resistance element into and out of igniting relation to said burner, and means for automatically controllingthe current n said element, said motor and said operating means; said automatic controlling means being arranged to cause the current to be thrown onto said element and said operating means to move said element into igniting relation before said motor is started, and also arranged to throw the current off of said element and cause said element to move out of igniting relation to said burner after the motor is started.

6. In an automatic system for controlling oil burners, a tire chamber, an oil burner having an electrical motor, an electrical igniting resistance element adapted to be heatedft incandescence land mounted for movement into and out of said fire chamber, electrical operating means for effecting movement of said element into and out of said chamber; electrical switch means for automatically controlling said motor, said operating means and the current through said element; and thermostatic means for controllin said switch means; said switch means eing arranged to cause the current t'o be thrownvonto said element and to cause said operating means to move said element into the fire chamber a redetermined period of time before said oil urner is started and to throw the current oi said element and result in thesame being moved out of ignitmcnt of said element into and out of said chamber, electrical switch means for automatically controlling said motor, said electro-magnetic means and the current through said element; and thermostatic means for controlling said switch means; said switch means being arranged to cause current to be thrown onto said element and said magnet to move said element into the fire chamber a predetermined period of time before the motor is started, said switch also being arranged to cause the current to be thrown off the element and said' element to move out of igniting position a predetermined time after the oil burner motor is started, and automatic means for interrupting the cycle of the system in the event of failure.

8. In an automatic system for controlling oil burners, a fire chamber, an oil burner having an electrical motor, an electrical igniting element adapted to be heated to incandescence and mounted for movement into and out of said fire chamber, electrical means for moving said element into and out of said chamber; electrical switch means automatically controlling said motor, said moving means and the current through said element; and thermostatic means for controlling said 'switch means, said switch means when in one position closing the circuit through said operating means and ignition device, and when in another position closing said circuit through said mot/or.

9. In combination, a burner having a motor, an igniting device comprising an electrical resistance unit, `operating means for moving said unit into and out of igniting position, switch meansV including a pair of contacts in series with said motor, a pair of contacts in series with said operating means and unit, and circuit closing means for said contacts acting to 'close said motor contacts after the movement of said unit into igniting osition; and a thermostatic ,device controlhng said switch means.

OSWALD E. DARCHE.

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