US2353464A - Control device for liquid fuel burners - Google Patents

Description

July 11, 1944. B. HAYTER EIAL CONTROL DEVICE FOR LI EQUID FUEL BURNERS Filed May 8, 1941 Patented July 11, 1944 Bruce Hayter, Santa F N. Men, and smiley Perry, Chicago, Ill., assignors to Oil Devices, Santa Fe, N. Mex., a limited partnership of Illinois Application May 8, 1941, Serial No. 392,50!

8-0laims. (CL ass-ca) The invention relates to an improvement in control means ior liquid iuel burners and has for one purpose the provision of improved means for causing or permitting a liquid fuel control valve to move sharply from a closed or minimum flow position to an intermediate fiow position, for example upon the actuation of a room thermostat, for thereafter to maintain a generally constant intermediate fiow, and at the end of a predetermined period to advance rather sharpshutofl means for sharply terminating the fuel fiow on cessation of operation, in order to eliminate the after fire, smoke and lazy combustion usually associated with pot type burners when the oilsupply is gradually reduced.

Other purposes will appear from time to time in the course of the specification and claims.

The invention is illustrated more or less diagrammatically'in the accompanying drawing wherein:

Fig. 1 is a vertical section through an embodiment of, the invention, illustrating the valve in minimum or closed position; and

Fig. 2 is a section on the line 2- -2 of Fig. 1.

Like parts are indicated by like symbols throughout the specification and drawing.

Referring to the drawing, I generally indicates the valve chamber or housing, having a cover plate 2, a valve element 3, a valve stem 4, and an upper valve control portion 5. I indicates the valve portion proper, provided with any suitable metering slot 8.

A indicates a, fuel supply line extending from the valve housing I, and it will be understood that any suitable means, not herein shown, may be provided for delivering to and maintaining in the chamber l a. suitable supply of fuel.

Assuming that the parts are in the cold or starting position, a springs tends to raise the valve to a top or full fiow position, which may be adjustably controlled by a stop in. In order to limit the initial upward movement of the valve 3 at the pilot stage, and to provide for a subsequent sharp upward movement, we provide theicllowing structure:

We provide a stem ll'mounted on the cover plate 2 and adjustable as to height, for example, by means of its upper screw. threaded end I2 and a cooperating manually adjustable nut 13. I3 is a heating or resistance element, herein shown as a coil resting in a cup of insulating material l5, s

, which may be adjusted on the stem H, as by the collar l6 and screw ll. Positioned abovegthe coil I4 is the bimetal disc l3, which when cold takes the full line position of Fig. l. The spring is, compressed between the disc l8 and the bottom of the cover 2, is of suflicient strength to resist the upward thrust of the light spring 9, which normally tends to open the valve 3 and is, therefore, effective to cause the disc I8, when in the full line position, to serve as a stop limiting the upward movement of the valve and thus providing a setting for minimum flow or pilot position of the valve.

A circuit for the coil is provided by the conductive lines 20 and II. The line H extends to the normally fixed contact 22 of a thermostat, the movable or bimetallic member of which is shown as at 23. The line 20 extends to the transformer VT and thence to the thermostatic member 23; It will be'understood that electrical current may be supplied to the circuit in any other suitable way, but this is a convenient circuit, which is closed in response to a drop in room temperature, which causes the member 23 to flex into circuit closing position. When this takes place and the resistance I4 is heated after a predetermined lag, the disc ll snaps sharply from the full line to the dotted line position of Fig. 1, and allows the light spring 8 to lift the valve 3. Its upward movement, however, is limited by the bimetallic disc 30, which is mounted on the stem 3i, normally upwardly thrust by the spring 32 and adjustable, as by the adjustable stop 33, in the ,cover plate 2.

When the abutment 5 of the valve stem 4 strikes the disc 33, it will be understood that it is cold and in the full line position of Fig. l, and stops the upward movement of the valve short at an intermediate position below the maximum fire position which would otherwise be permitted the disc 30 snaps sharply from the full line to the dotted line position and permits the spring.

9;to lift the valve as high as the stop iIB will permit.

It -will be noted that the speedpf heating of the disc 30 may be controlled by adjusting the coil 31 toward and away from it. If the coil 3'! is close to the bottom of the disc 30, it is effec-' tive to heat the disc directly, in addition tothe heat conducted along the preferably metallic stem 3i. If, on the other hand, thecoiLis moved a substantial distance clown away from the disc }30, then the time lag isincreased, and theheat of "the coil 3'! reaches the disc 30 primarily by conduction along-the stem 3|.

It will thus be understood that, when heat is first called for by the room thermostat, the disc l8, which normally holds the valve 3 at pilot flow if a. pilot' flame is used, or at full closure if no oil pilot is used, remains in the full line position. It will be understood that, if an oil pilot is used, the valve 3 is so related to the valve seat and is so formed o'r'adjusted that there will always be a; minimum or pilot flow of fuel, and for purpose of illustration it will be 'assumed that the structure herein shown is provided for a' burner with anoil pilot. When the room'thermostat is closed bya demand for more heat, the circuit for the coil [4 is closed, and after a short lapse of time the disc i8 snaps into the dotted line position, and since the snapping oi the disc'is almost instantaneous, the light'spring 9 canisharply raisethe valve 3 from pilot or minimurn'se'tting'to the interme-,

'diatestting,'asjdetermined" by the position of the disc. It is desirableto have an intermediate setting ,for a reasonably controlled length of time,.and this time'can be accurately'con trolled by adjusting the position of the heater 31." Ina'ny event the .eilect'of the snapping oi the disc l 8 t'o the ,dotted line'position is tolclose the circuit through. the ,heater 31, and thereafter,falter a'prdeterminedl 1ag, the disc 3! snaps from the full'linefto thedotted line. position,and the valve is againsharply moved upwardly by the spring 9 as high as the stop ll willpermit. l v

After heat is no longer calledforby the room thermostat, and thecircuit for both heaters is simultaneously broken, both the discs l8 and warp back into the fullline position. Preferably the disc is made to operate more rapidly than the disc 30, so that it 'willsharply move the valve 3 cleardown to the minimumsetting. It willbe realized that, whereas;a:practical and operative device is described and .illustrated, nevertheless many changes maybe made in the size, shape, number and disposition of parts'without departingfifrom the spirit of the invention. We therefore wish the description and drawing to be taken' as in abroad sense illustrative or diagrammatic, rather than as limitingus'to our preciseshowing. V

We claim:

1. In valve control means for use with liquid fuel burners. a valve housing, a valve member movably mounted in said housing, means for normally holding the valve member in closed or minimum flow position, including a bimetallic warping disc, means for causing said valve member to move sharply toward open position, including means for heating said warping disc, means for maintaining said valve member at a subsequent intermediate flow position for a pre-' determined period, including a second bimetallic warping disc, and means for thereafter causing movement of the valve member to full flow posi-,

tion, including means for heating said second warping disc.

2. In valve control means for use with liquid fuel burneraa valve housing, a valve member movably mounted in said housing, means for normally holding the valve member in closed or minimum flow position, including a bimetallic warping disc, means for adjusting the'minimum flow position of the valve, including meansfor bodily moving said warping disc, means for causing said valve member to move sharply toward open position, including means for heating said warping disc, means for maintaining said valve member at a subsequent intermediate flow position for a'predeterrnined period, including a second bimetallic warping disc, and means for thereafter causing movement of the valve memdetermined period, including a second bimetallic warping disc, means for adjusting the intermediate setting of said valve, including means for bodily moving' said second warping disc, and means for thereafter causing movement of the valve member to full flow position, including means for heating said second warping disc.

4. In valve control means for use with liquid fuel burners, a valve housing, a valve member movably mounted in said housing, means for normally holding the valve'member in closed or minimum flow position, including a bimetallic warping disc, means for causing said valve member to move sharply toward open position, including resistance means for heating said warping disc, means for maintaining said valve member at a subsequent intermediate flow position for a predetermined period, including a second bimetallic warping disc, and means for thereafter causing movement of the valve member to full flow position, including resistance means for heating said second warping disc, and circuits for said resistance means, and a. source of electric power therefor, and a, room thermostat in circuit with said electrical power source.

5. In valve control means for use with liquid fuel burners, a valve housing, a valve member movably mounted in said housing, means for normally holding the valve member in closed or minimum fiow position, including a bimetallic warping disc, means for causing said valve member to move sharpl toward open position, in-

" moving the resistance means for the second disc toward and away from said disc.

6. In valve control means for use with liquid fuel burners, a valve housing, a valve member movabiy mounted in said housing, means for normally holding said valve member in closed or minimum flow position, including a bimetallic warping disc opposed thereto, means for causing said valve member to move sharply toward open position, including resistance means for heating said warping disc, means for maintaining said valve member at a subsequent intermediate flow position for a predetermined period, including a second bimetallic warping disc in the line of movement of said valve member when the valve member is released by the warping 0f the first mentioned warping disc, and means for thereopen position, including resistance means for heating said warping disc, means for maintaining said valve member at a, subsequent intermediate flow position for a predetermined period, including a second bimetallic warping disc in the line of movement of said valve member when the valve member'is released by the warping of the first mentioned warping disc, means for thereafter causing movement of the valve from full flow position, including resistance means for heating'said second warping disc, and means for closing the circuit for said last mentioned resistance means in response to the upwarping of the first mentioned warping disc.

8. In valve control means for use with liquid fuel burners, a valve housing, a valve member movably mounted in said housing, means for normally holding said valve member in closed or minimum flow position, including a bimetallic warping disc opposed thereto, means for causing said-valve member to move sharply toward, open position, including resistance means for heating said warping disc, means for maintaining said valve member at a subsequent intermediate flow position for a predetermined period, including a second bimetallic warping disc in the line of movement of said valve member when the valve member is released by the warping of the first mentioned warping disc, means for thereafter causing movement of the valve from full flow position, including resistance means for heating said second warping disc, means for closing the circuit for said last mentioned resistance means in response to the upwarping of the first mentioned warping disc, and means for varying the time lag between the closure or such circuit and the upwar ing oi the second warping disc.

BRUCE HAY'I'ER.

QTA I B R Y.

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