US1711443A - Setts - Google Patents

Description

April 30, 1929. R, F, BOGER 1,711,443

PILOT CUT-OFF FOR GAS BURNERS Filed sept. 1e, 1927 Z 55 M jg 20 jy 77M W14 vdi/M7 is intentionally that when the flow of gas to thef Patented Apr. 30, 1929.

UNITED STATES PATENT .,oFFICE... I

ROBERT E. EOGEE, oF EoSToN, MASSACHUSETTS, AsSICrNoEy To SPENCER THERMOSTAT COMPANY, E CAM-BRIDGE, MASSACHUSETTS, A CoRPoEATToN or MASSACHU-y SETTS.

:PILOT CUT-OFFv FOR GAS BURNERS.

Application leSeptember 16, 1927. Serial No. 219,939.

vThis invention relates to-.eoutrol systems for gas burners'and 'more particularly to a control System including a thermostat l0- cated in the high heat zone where the gas is burned and adapted to cut otl the flow of gas in the event that the iame is accidentally extinguished.

Heating by gas is` now very common for water heaters, stoves, furnaces and certain types of automatic krefrigerators and it is customary to vary and in some cases to lcut off the heat applied by automatic or manu-- ally controlled devices, the burners being often relatively inacessible. For the purpose of insuringthe continuous automatic action of burners of this Character, it is customary to provide a pilot to relight the main burner when necessary, although the pilot need not. be. used if the controlling means is adapted merely to regulate the height. of the 'laiue of the main burner. ,lt sometiinesfhappens in this lutter case that the flame in the main hui-ner is accidentally extinguished -or in the case where a pilot is used and' the main burner i extinguished, the pilot also goes out, so main burner but escapes to the surrounding building in which the biii'ner is located .with the attendant risks to the occupants both from tire and asphyxiation.

Among the objects of the present invention, therefore, are to provide an automatic con'- trol or safety device responsive to the temis recstablished it is not. ignited,

' l perature of the pilot, if one is used, or to the temperature in the heated zone in which the gas is burned, which will function quickly and in a certain manner to cut otlf the entire flow of gas both to the main gas burning devices and the pilot, if one is used, in the event that the flame is accidentally extinguished; to provide for religliting the devices without the necessity of first warming the thermostat; to provide in control devices of this character a cut-off valve so4 located as to be out of the high heat zone of the burner and consequently more 'durableand less likely to get out of order; and generally to improve devices of this character.

Other objects and advantages of the invention will be apparent .from the following specification and drawings, in which:

stem.

parts of the Y l o v I provide. means, appended claims when taken in conjunction with the accompanying A 1l` l i 0 i i i l4 ig. 1 isa plan view of the valve, thermostat and pilot;

Fig. isva central section taken on the line in 141g. 1 showing the valve open'; I l1 ig. 3 isa section similar to Fig. 2 showing the valve closed;

. 151g. 4 isa fragmentary lsection showing the and Figo is a fragmentary section Showing a modified form ofinanual resetting means for the valve.

, y The device comprises a valve casing gen-l erally indicated at 1 which is here shown as means of mounting the thermostatic disk;

made up of two parts 2 and Sthreaded together at 4, the lower part 2 having a wall 5 therein provided with an aperture 6 through which gas may flow from the inlet end 7 Lto the outlet end 8. The wall is provided with a centralaperture S) iu which is mounted the stem 10 of a poppet valve 11 which may be fixed thereto in any suitable manner, as for example by the nut 12 threaded on the valve At its lower end the valve stem l() is provided with an outwardly extending annular flange 13 onwhich is seated a helical compression spring 14 extending between this flange and the lower side of a boss 15 which is preferably formed integral with the wall 5 about the valve stem, this spring thus tending to force the valve 11 toward its closed position where the downwardly turned annular flange portion 16 Seats upon the upper surface of the wall 5. The lower endof the valve stein 10 is provided with a recess 17 in which is located a ball 18. A cani member 19 is fixed to a. sh aft 20 which extends through a suitable packing inthe side of the valve easing 2 and is provided at its outer end with a thumb nut 21 by which the cam 19 maybe rotated. l The cani 19 is aligned with the valve i i stem 1() and is adapted to engage the ball 18 so 4that upon rotation of the cam, the bal-l and valve stem are forced upwardly toople'n the valve, as seen in Figs. 2. and 3. i I. preferably provide a notch 22 in the highest por.- tion of the cani 19 in which theball 18 may seat in the open position of the valve, whereby to prevent accidental dislodgmentafrom openvposition. f

including a thermostat, for .moving the cani to close the valve when such action is necessary, such means taking the form` of a tube 23 threaded into the lower portion 2 of the valve casing, as shown at 24, a jam nut being provided if it is desired to hold the ytube more lirmly to the valve casing. The tube 23 is provided with an enlargement 26 which cooperates with a similar enlargement 27 which may beintegral with the pilot member 28, the latter having a suitable opening for the egress of gas to sustain a pilot frame. Enlargements 26 and 27 are provided with suitable interengaging flanges 29, as seen in detail in Fig. Il, and are provided with an annular spacing ring 30 for a vpurpose later to be described. A bimetallicdisk 31 is mounted between the enlargements 26 and 27 with its periphery in heat conducting relation therewith. In order that the disk 31 will not be so tightly gripped between the members 26 and 27 as to prevent its efficient operation the spacer ring 3() is made slightly (e. g. .005 inches) thicker than the disk. The inner diameter of this spacing ring may also be slightly greater than the diameter of the disk 31, as indicated in Fig. 4, to prevent binding.

The disk 31 is preferably bi-metallic, being formed of two component disks welded together, the materials such as iron and brass of the respective disks havingdiiferent coefficients of expansion. The disk 31 is normally cupped (as by swaging) in such direction that the component part having the higher coefiicient of expansion is on the concave side. Consequently upon raising the temperature of the disk the unequal expansion or' the materials formingthe disk will cause a tendency to flatten the cupped surface until at a predetermined temperature a sudden curving in the opposite direction occurs, which reversal of shape will be maintained until the temperature has been substantially lowered. Thereafter upon reaching a substantially lower temperature, the disk will suddenly return to its initial shape. The materials and thickness of the component parts and the degree of curvature are so chosen that the disk will snap in one direction when heated to the desired temperature (e. g. 120o F.) and will snap back at a lower temperature (e. g. 100o F.). Suitable materials are sheet brass and nickel steel having a thickness of .005 and .005 inches respectively and suitable cupping for in diameter is .02 inches.

It will be understood however that the present invention is not limited to any particular combination of materials having different thermal coeilicients of expansion but is intended to embrace in its scope any combination of materials having dissimilar thermal coeticients of expansion sufficient to cause the reversal of curvature. Furthermore, the two materials comprising the composite thermostatic disk mav be secured together in any desired manner y riveting, soldering, brazing, or otherwise although it is preferred to unite a disk S inches the materials comprising the disk by welding or 'similar means to secure a substantially indivisible sheet.

A rod 32 is rigidly fixed-to the center of the disk 31 in any suitable manner as by a nut 33 engaging a reduced threaded portion of the rod which protrudes through a central aperture in the disk. The rod 32 extends axially' through the tube 23 into the interior of the valve casing and is aligned with the cani 19.

From the above description, the operation of the device will be obvious. Starting with the parts in the position shown in Fig. 2 when the burner and pilot are both lit, the thermostat will be cupped to the right, thus keeping the rod 32 at its right-hand position. It' for any reason the pilot and the main burner are extinguished, the thermostat will cool until its critical temperature is reached, at which time it will snap abruptly to the left, as seen in Fig. 3, thus pushing the rod 32 to the left and rotating the cam 19 in a counterclockwise direction to permit the spring 14 to close the valve. lnasmueh as the gas feed to the pilot is from the outlet side of the valve and thence through the annular space between the tube 23 and the rod 32 and through the perforations 34 in the disk 31, it is obvious that when the valve 1l is closed,` not only the main burner, but lthe pilot as well, will be completely turned ott', thus entirely preventing the escape of gas. When it is desired to relight the burner, the thumb screw 2l is rotated to. open the valve and the burner is lighted in any suitable manner.

of gland packings in connection with gas devices, so that a manual resetting device such as is shown in Fig. 5 must be resorted to, that is, in which the rod 20 extends through the side of the valve casing 1 and through a suitable boss 35 without the use of packing and is provided with a squaredend 36 which may be engaged by any suitable tool, the whole being normally covered by a cap 37 which may be threaded to the outside of the boss 3 5 as shown at 36.

In some cases the use of a pilot 28 may be dispensed with, in which case the enlargement 27 is merely provided with a closed end and the thermostat may be iniperforate. In this event the thermostat is responsive solely to the heat of the main burner, the other parts being exactly the same as in the form above described.

As 'many changes might be made in the de- In some places the laws prohibit the usel vice as shown and described without departing from the spirit of my invention, I do not wish to be limited except by the scope of the appended claims.

I claim:

1 A gas burner control device comprising a gas supply line, a poppet valve therein, resilient means tending to hold said valve closed, a cam pivoted to the valve casing and' closed, a cam pivoted to the valve casing and `aligned with the valve stem to open-the valve,

pilot, and means connecting said disk With the interior of the valve casing and adapted torotate said cam to permit the closing' of the valve when the disk cools to a predeter- 'mined temperature due to the pilot being extinguished. v

2. A gas burner control device comprising a gas supply line, a poppet valve therein, resilient means tending to hold said valve aligned with the valve stem to open the valve and hold it open against the action of said resilient means, a gas pilot, means for con` ducting gas from the outlet side of said valve to said pllot, a thermostat associated with and adapted to be heated by said pilot, means operatively connecting the thermostat with said cam so arranged that when the thermostat cools to a predetermined temperature due to the pilot being extinguished it will move the cam out of line with the valve stem and permit the valve to close undcr the actionvof said resilient means, and manual means for resetting the valve to its open position.

3. A gas burner control device comprising a gas supply line, a poppet valve therein, resilient means tending to hold said valve closed, a cam pivoted to the valve casing and aligned with the valve stem to openthe valve and hold it open against the action of said resilient means, a tube mounted in the valve casing and communicating With the outlet side of the valve, the tube having a pilot-opening at the end remote from the valve, an enlargement in the tube adjacent tothe pilot opening, a snap action thermostat in said enlargement in heat conducting relation with thekwalls thereof, and a rod rigid with the thermostatic element and extending through said tube to contact with and rotatesaid cam to permit the valve to close when the thermostat is cooled to a predetermined temperature due to the pilot being extinguished, whereby the valve' may be located out of the hot zone in which the gas is burned.

4. A gas burner control device comprising a gas supply line, a poppet valve therein, resilient means tending to hold said valve closed, a cam pivoted to the valve casing and aligned with the valve stem to open the valve, the cam having a notch ye'n,f:,1'ageable with the end ofthe valve stem at the full open position of the 'valve to revent accidental closing thereof, a gas pilot aving a gas supply tube connected to the outlet side of said valve casing, a bi-metallic disk thermostat associated With said pilot, a rod extending from said disk to said valve and cooperable with said cam to move the latter and permit said resilient means to close the valve when said disk has cooled to a predetermined temperature.

5. A gas burner control device comprising a gas supply line, a poppet valve therein, resilient means tending to hold Said valve closed, a cam pivoted to the valve casing andA aligned With the valve stem to open the valve, the Vcam having a notch engageable with the end of the valve stem at the full open position of the valve to prevent accidental closing thereof, a gas pilot having a gas supply tube .connected to the outlet side of said valve casing` an enlargen'ient in said tube adjacent to said pilot, a perforated bi-mctallic disk thermostat in said enlargement with its periphery in heat conductingrelation with the walls thereof, a rod rigid With the center of said disk and extending axially through said tube to the interior of said valve casing, the inner end of said rod adapted to engage said cam abruptly and positively to rotate it to permit the valve to 'be closed by the action of said resilient means when the thermostatic disk has cooled to-a predetermined temperature, and manually operable means to resetthe cam to open the valve independently of the thermostat, whereby the valve may be located out of the high heat zone Where the gas is burned.

Signed by me at Cambridge, Mass., this 14th day ofSeptember,1927.

- ROBERT F. BOGER.

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