US2077297A - Automatic control and electric ignition for gas burners - Google Patents

Description

p il 3, 1937- J. B. WHLLHAMS I AUTOMATIC CONTROL AND ELECTRIC IGNITION FOR GAS BURNERS' Filed Oct. 1.. 1954 James 15. MY/z'azms ATTORNEY Patented Apr. 13, 1937 PATENT OFFICE AUTOMATIC CONTROL .AN'D ELECTRIC IGNITION FOB GAS BUBNEBS James Bernard Williams, Minden, 1..

Application October 1, 1984, Serial No. 748,477

The object of the invention is to provide a control for gas burners, as well as an electric ignition for the same, the two being so coordinated that there may be no chance of the escape at '5 any time of unburned gas in the event 01 failure either through the gas supply or through the ignition equipment; and generally, to provide an automatic gas burner control and ignition which is of simple form, susceptible of cheap manuiac- 'ture, of a character that is not practically subject to disarrangement or failure of its parts, and oi a form which will permit its installation without the necessity of skill on the part of the person making the installation.

With this object in view, the invention consists of a construction and combination of parts 01- which a preferred embodiment is illustrated in the accompanying drawing, wherein Theiigureisavlewpartlyindiagramand partly in section 01 an appliance constructed in accordance with the invention.

The burner I0 is not directly i nited from the ignition equipment but from a pilot burner ii which is ignited by the ignition equipment. The main burner I0 is fed from the gas supply con- -ductor I! through a gas pressure chamber ll defined by a diaphragm II and certain walls oi the casing II, the latter being formed in two parts consisting of the lower section Ila and the upper section "a which are bolted together by means of fasteners I. passed through the flanges II, with which both sections oi the casing are formed. The diaphragm is marginally interposedbetweentheconnectingedgesoi'thecas--v ing,andatitscenteriseonnectedwithapcst 4o ilpassingslidablythmughacentral guideopeningin the uppersection its oi thecasing and throughanopeningintheguldearm2lwith which-the upper section or the casing is formed; Interior to the casing, the post carries a lateral 5 arm 2i terminally provided with a contact 22,

the latter being insulated from the am but positioned to engage a complement'ai contact 23 car riedat the extremity of a lever 24 the latter beingpivotallymountedonabaseplate lloiinso misting material, on which an L-shaped abutment member 20 is also mounted. The-contact end 0! the lever 24 is yieldingly toned downwardly intoengagement with the end of the short leg oi the abutment member 20, a compression sispdngflbeingemployediorthispurposeand being telescoped over projections at the extremities oi the lever and the abutment member.

'Thus downward movement 01' the lever carrying contact is limited by the abutment member, but the lever may yield in an upward direction, when the contact 23 is engaged by the contact 22, as will be the case when the post is elevated, due to the pressure of gas in the chamber i4 acting on the underside of the diaphragm IS.

The supply pipe, in which at a remote point from the burner is positioned the control valve 2|, is in communication with the gas pressure chamber, but the burner III is in communication with said chamber only when the valve 29 is in open position, this valve being interposed bechamber. The valve 29 is formed with a stem II which extends through a guide opening in the bottom of the casing section lia and is terminally provided with a plunger ll, which acts as the core of a solenoid 32, the latter being wound on a bobbin 33 of brass or other non-magnetic mate 20 to, iacilitate the assembling operation. The

bobbin as is extended below the lower end of the solenoid winding and is closed with a removable cap I, suiiiciently tight fitting to prevent the escape or any gas that-might find its way out of the outlet channel 01' the casing around the hole or guide opening through which the stem ill. passes. Buiilcient guide clearance is provided between the plunger and the wall of the bobbin to permitthereadytransieroiairiromonetothe other in the movement or the plunger, so as to prevent sluggish operation or the latter.

'lhepilotburnerilisfedthroughabranchtubular conductor 31 tapped into the main supply pipe it between the control valve ll and the gas pressure chamber ll, the conductor 31 being provided with a manually adjustable valve II to regulate the supply of gas to be admitted to the pilot burner; A valve 3! is interposed in the pilot supply pipe or conductor 31, being housed in a valve case ll andhaving a stem 4| terminating in a solenoid plunger core 42. The core It moves within the bobbin 3, which is also of non-magnetie material, irictionally or otherwise secured tween the inlet and outlet or the gas pressure to a pendent boss 44 on thebottom of the case 40. The solenoid winding 45 is wound upon the bobbin, the latter at its lower end being closed with a movable gas tight cap 46 of the same form as the cap 36.

The solenoids 32 and 46 which constitute the actuating means for the valves 23 and 33 are actuated from the secondary of a transformer 41, whose primary is fed from the line conductors 43, in series with the switch comprising the contacts 22 and 23. The ignition coil 49 is also fed from the secondary of the transformer 41 in one position of the thermostatically operated singlepole double-throw switch, which comprises the fixed contacts 50 and ii and the movable contact 62, the fixed contacts being carried on a bracket 53 and the movable contact being carried on a strip of thermo-metal 54, also carried upon the bracket. The thermo-metal and flxed contacts are insulated from the bracket and the fixed contact 5| is electrically connected with one of the primary terminals of the spark or ignition coil 49, the common terminal of which is grounded. The fixed contact 50 is electrically connected with the solenoid 32 so that when the movable contact 52 engages the contact 53 the solenoid 32 will be energized.

The electrode 55, by means of which the pilot burner I i is ignited, is electrically connected with the secondary terminal of ignition coil 49. The ignition coil is of the vibrator type, which has been found to give the most intense spark.

To provide for remote control through the ignition apparatus, a switch 53 is interposed in the supply line 43.

In the operation of the invention, the burner is absolutely precluded from being ignited if the switch 56 be open or if the valve 23 be closed. The latter must be open and the former closed for the apparatus to operate. If gas be present in the supply pipe II, it will enter the pressure chamber l4, and exerting the pressure on the diaphragm IE, will bulge the latter upwardly, thereby elevating the post It to engage the contact 22 with the contact 23; Then a circuit is established in the primary of the transformer 41 over the supply conductors 43. With the primary of the transformer energized, the secondary will one terminal of the transformer secondary. En-

ergizing of the solenoid will result in the elevation of its core 42 and the opening of the valve 43, so that gas may flow through the conductor 31 to the pilot burner, such gas being ignited by the sparking at the electrode II, since, when the thermo strip 54 is cool, the contact 52 will be in engagement with the contact ii and current from the secondary of the transformer may fiow from the latter over the engaged contacts to the primary of the ignition coil, thence to the ground andback to the transformer. But upon the pilot burner being lighted, the thermo strip will beheated, with theresult thatthe unequaled expansion of its constituent laminae will result in engaging the contact II with thacontact ll, thus breaking the circuit on the primary of the ignition coil, and therefore rendering it inert, so thattherewiilbeno sparkingatitselectrode.

of the contacts l2 and II will place the solenoid u m circuitwith the sec- 52 and 33, thence through the solenoid winding and the ground back to the secondary. By energizing the solenoid 32, the resultant elevation of the plunger 3| will move the valve" to open position, so that gas may flow to the main burner ill to be ignited by the previously ignited pilot burner.

Should the gas supply fall, the pressure in the pressure chamber i4 will drop and the diaphragm I5 will resume its normal position, separating the contacts 22 and 23, thus depriving the transformer 41 of current, and therefore depriving both the solenoids 32 and 45 of current, so that their cores will drop and their valves be moved to closed position. Thus communication between the supply and both the main and pilot burners will be cut off. On the resumption of the gas supply, the pressure again obtaining in the gas pressure chamber i4, will result in the re-engagement of the contacts 22 and 23, and thus the establishment of former conditions, resulting first in the re-ignition of the pilot burner and thereafter the main burner.

If the switch 56 be open during the failure of the gas supply, or if the ignition circuit be affected, so that the pilot burner cannot be ignited, the gas supply to the main burner cannot be established, since that is wholly dependent on the engagement of the contacts 52 and III, which can only be maintained when the pilot burner has been ignited.

The valve 33 is not an absolute necessity to the proper functioning of the device, but is only included as an extra precaution against gas escape.

It may, therefore, be omitted where the escape tion between the-pressure chamber and the burner, a pilot burner having a conduit feeding it from the 'gas supply source from a point ahead of the pressure chamber, a valve interposed in the pilot conduit, an electrical actuating means for the burner valve, an electrical actuating means for said pilot valve, an energizing circuit across which the pilot valve actuating means is connected, electrical ignition apparatus for the pilot burner, a double-throw single-pole thermostatically operated switch normally in one of its circuit closing positions to connect the ignition 1 apparatus in the energizing circuit 'andheat actu; ated from the pilot burner to its other circuit closing position to connect the burnervalve actuatingvmeans inthe energizing-circuit, and a normally open "circuit closer the energizing circuit and v operatively 7 related with the gas pressure chamber for movement closed position on the attainment of a mined pressure in the pressure chamber.

2.Anapplianceofthekind ing,'in combination with a gasburner and a gas conduit feeding the same from, if! supply source, a burner .valve interposed in said; combat and controlling. the admission of gas to the indicated com bu e meansfor normally retaining:

in closed position, electrical means for said valve.a pilot burner having'aconduit from I 2,017,201 3 ahead-oi the burner valve. a valve interposed in opening means and to the ignition apparatus, the pilot conduit, means for normally retaining and means responsive to combustion at the pilot the pilot valve in closed position, electrical means burner and operatively connected with the igni- Ior opening said pilot valve, ignition apparatus tion apparatus to tie-energize the latter and admit 5 for the pilot burner, means responsive to a preenergizing current to the burner valve opening I determined pressure oi as in the first said eonmeans only after ignition oi. the pilot burner. duit to admit energizing current to the pilot valve JAMES BERNARD WILLIAMS.

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