US1703854A - fonseca - Google Patents

Description

Feb. 26, 1929. 1,703,854

E. L. FONSECA PILOT LIGHT CQNTROL Filed Feb. 20, 192.6 2 sheets-sheet 1 5 5 I I I I I J MMM ATTORNEYS Feb. 26, 1929. A 1,703,854

5* E. L. FONSECA PILOT LIGHT CONTROL Filed Feb. 20,:1926 2 Sheets-Sheet 2 l TOR Z1144 m,

ATTORN EYS Patented Feb. 26, 1929.

UNITED STATES PATENT OFFICE.

EDW'ARD L. FONSEOA, OF NEWARK, NEW JERSEY, ASSIGNOR TO THE WILGOLATOR GOMIANY, OF NEVJARK, NEW JERSEY, A CORPORATION OF DELAWARE.

PILOT-LIGHT CONTROL.

Application filed February This invention relates to thermostatic control devices and has to do more particularly with the thermostatic controller which governs the supply of fuel to a'main burner in accordance with conditions which prevail at a pilot burner by which the gas flowing from the mainburner is ignited. As the inven ticn is of special utility in automatic gas heaters, that adaptation of it will be described, but it is to be understood that such use is merely typical.

In gas heaters of the automatic type, such, for example, as those commonly used in resi dences for supplying hot water, the supply of gas to the main burners is under the control of a thermostatic mechanism which is responsive to changesin temperature in the body of liquid being heated. This mechanism actuate-s a valve in the gas supply main, and when the liquid cools to a predetermined low temperature. the mechanism opens the valve and flows to the burners. Similarly, when a .predetermined high temperature is reached, the valve isclosed and the burners are extinguished. In order that the burners may again be lighted when occasion arises, is necessary to maintain a pilot light which is constantly burning, at some point adjacent the burners. This is a small iiame and it sometimes accidentally extinguished, as, for instance, by drafts. If the temperature of the liquid should fall to the point at which the main valve is opened, while the pilot light is out, gas will escape free y from the main burners, and this may lead to serious accidents. It is therefore desirable inheaters of this type to provide a control mechanism to govern the supply of to the main heater burners which is responsive to the heat'generated by the burning of the pilot light so that no gas can flow 20, 1926. Serial No. 89,641.

placed near the other end of the line. The element includes a bi-metallic strip which is arranged to have a free end which moves in accordance with temperature changes, and this moving'end of the strip is connected to the movable member of the valve. The valve opens and closes against the gas pressure in the main, and the arrangement is such that when the pilot burner is lighted the end of the strip moves to raise the movable part of the valve from its seat. Such movement ofthe valve part is opposed by the gas pressure in the main acting upon the upper surface of the part, and an appreciable stress is put upon the strip before the gas pressure is overcome. lVhen this occurs, the movable part of the valve suddenly snaps open so that the full opening of the valve is accomplished, and as a result the entire main beyond the valve is at once filled with gas andno explosive mixture of gas and air is produced. Similarl if the pilot light burner is to be extinguished, the movable part of the valve is again closed with a snap action. A pressure is exerted on the movable part of the valve, due to the friction of the gas flowing past it, and also to the velocity head pressure of the gas impinging on the part. As the movable part approaches its seat, the sum of these pressures builds up rapidly and overcomes the cantilever spring resistance of the thermostatic element until, when the part closely approaches its seat, is is suddenly seated with a snap action, so that the valve is thus completely closed and again an explosive mix ture is prevented from being delivered to the burner.

The new pilot light controller may be used with either a blue or a yellow flame pilot, and both types of burner will be described.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which Fig. 1 is a side view, partly in section, showing the new control mechanism in its relation to the gas supply main, and the heater burner,

Fig. 2 is a view largely diagrammatic, showing the, complete installation including the controller responsive to temperature changes in the body of liquid or chamber to be heated,

. controller, and

Fig. 3 is a View in perspective, showing the mounting of the thermostatic controller inrelation to the pilot light burner, L

Fig. 4 is a side view .ofa slightly modified mounting,

Fig. 5 is a view of a modified type of burner which may be used with the con-' troller,

'Fig. 6 partly insection, of a modified form of the Figs. 7 and 8 are diagrammatic views showing the piping arrangements.

Referring now to the drawings, the gas heater is generally designated 10, and consists of a casing 11 in which is a coil 12, heated by burners 13. The coil is in communicati'on with a tank 14, so that liquid from the tanl: continually circulates through the coil. The burners 13' are of any standard type, and are supplied with gas from a manifold15 connected to a main 16. In this main is a valve 17 which is controlled by a thermostatic controller generally designated 18 and having a temperature-responsive element 19 projecting into the tank 14. The valve 1'? is opened and closed by the thermostatic controller in accordance with variations in temperature in the body of liquid. The supply -main 16 is also provided with a manually. operated valve 20' and bet-ween these valvesis a third valve'21, actuated by a thermostatic mechanism generally designated 22, which operates in response to heat generated by the burning of gas inthe pilot light burner23.

'Asshown more clearly in Fig. 1, the valve 21 is, in general, of standard construction, having a seat 24 on which lies a ball 25. As the ball is raised from its seat, gas from the main may pass through the valve to the main heater burners, under the control of the device 18. On the top or" the body of the valve is a bushing 26 threaded in position and terminating-at its lower end in a tubular extension 27, through which are orifices 28. In the upper end of the bushing is threaded a 1 pipe 29,11eld in place by an adjusting locl: nut 30, bearing against the upper end of the bushing 26. The interior oi the tube 29 is in communication with the main in front of the valve, in part through the orifices 28. The ball 25 of the valve 21. is movable up and down in-the tubular extension, which acts as a guide for the ball. Mounted in the side of the tube 29 at some distance above the valve 21. is a fitting 31, having a passage 32 inconnnunication with the interior of the tube 29. This fitting has a passage 33 having an opening at its lower end controlled by a needle valve 34 which has a shank'35 threaded into the lower end of the fitting and held in adjusted position by a nut 36. Threaded on the fitting 31 is a burner tube 37, having a plurality of air inlet openings is aview partly in elevation and 38, a short distance above the end of the passage 33, and at its upper end the burner tube'has a series of burner orifices 39 arranged in' a line. The line of orifices partially encircles the tube, as indicated at 40, and then extends up in a straight line along one side, as indicated at 41.

The valve 21 and the tubes 29 and 37 are so positioned that the orifices at the top of the tube 37 lie close to the upper end of the burners 13 so that when the pilot light burner is lighted, its flames will cause any gas flowing from the burner 18 to be ig nited.

Threaded on the end of the tube 29 is an elbow 42, provided with a split extension 43 which clamps the tube 37. W'ithin the elbow, secured in any convenient manner, as by rivets 44, is an L-shaped bracket 45, to which is secured one end 46 of a U-shapcd thermostatic element 47 This element is made of two metals in the ordinary manner, and its free end 48 is placed above the tube 29. The element is so arranged that when exposed to heat the free end 48 moves toward the fixed end secured to the bracket. The element is partially enclosed in a closed tube 49, threaded in the fitting 42.

Disposed within the tube 29 is a rod 50 secured by means of a nut 51 to the ball 25. This rod extends through an opening in the upper end of the element and carries a washer 52, held in place by a cotter-pin 53, above the end of the element. Below the element is a washer 54, against which bears one end of a light spring 55, encircling the rod 50. The lower end of this spring bears against a washer 56 held in place by a cotter-pin 57. It will be seen that with this arrangement, when the element is heated so that the bow contracts, the end of the element will engage the upper washer 52 and lift the rod, thus causing the ball 25 to be freed from the seat 24. When the element is cold so that its two legs are sprung apart, it will exert a downward pressure which will be transmitted through the spring 55 to the washer 56, thus causing the ball to seat. It, after the ball is seated, there is any further tendency of the element to expand, this is taken up by the collapse of the spring 55.

It will be seen that the ball is exposed to the pressure of the gas in the main 16 and consequently when the thermostatic element is heated and its free end begins to rise, tending to lift the ball from its seat, such movement will be opposed by the gas pressure acting upon the upper side of the ball. This pressure will resist the movement oi? the element and tend to hold the ball on its seat until the element is placed under a considerable tension. hen the tension slightly exceeds the pressure of the gas, the ball is lifted from its seat and the gas pressure becoming substantially equalized on both sides of the ball, the latter is free to be moved by the element. As the element is still under some tension, this results in the ball being lifted quickly a substantial distance from the seat so that the valve has a snap action in opening. Similarly in closing, the free end of the element tends to force the ball downwardly on its seat, and this movement is assisted by pressure derived from the impingement of the gas upon the top of the ball, and also by the friction of the gas past the ball. The forces acting on the ball build up r. idly as the ball approaches its seat and .inally overcome the cantilever-spring resistance of the thermostatic strip and cause the ball to seat with a snap action. By this arrangement, therefore, the snap action of the valve in opening andclosing insures that that part of the main 16 beyond the valve is either in full communication with the gas supply, or else completely out off from it, and thus small amounts of gas are not permitted to How to the burner, resulting in mixture with the air in the burner and producing an explosion.

In the form shown in Fig. 1, the burner tube. 37 is clamped in position relative to the tube 29, by a clamp 13 which forms a part of the elbow 42. l/Vith this arrangement the thermostatic element 47 is directly con nected through. metal to the tube 37, from which the gas is supplied to the pilot light flames. When the heater is to be ut in operation the main valve 20 is manually opened and a sufiicient quantity of gas will flow from the main through the tubes 29 and 37 to the pilot light orifices. As the gas burns it heats the upper end of the tube 37 and the heat is conducted through the metal parts directly to the element so that in a short time, the free end of the element moves to open the valve 21 and thus admit fuel to the burners 13, these burners being ignited by the flames at the end of the tube 37. The arrangement of the parts is such, however, that although a good i nition of the main burners lii is provided for, the thermostatic element is placed a considerable distance from these burners so that the action of the thermostatic strip in it is not materially affected by the main burners. Similarly, by altering the length of the tubes 29 and 37, the valve 21 can beplaced at any convenient distance relative to the burners 13, and the opening of the valve 21 may easily be regulated by screwing the tube 29 111 or out of the bushing 26. The tube 29 has a fine thread at its lower end to provide for an exact adjustment of the lift of the ball 25.

Another advantage of the present construction is that the thermostatic controller for the pilot light burner may be placed either vertical, horizontal, or at any inter mediate angle. In some installations, it is desirable that the pilot burner should extend vertically, while in others the most convenient arrangement is to have the pilot burner lie horizontal in the chamber in which the main heater burners are placed. The present device is capable of installation in any desired way, and furthermore the line of fiames 39 can be varied in any way that may be required by the peculiarity of the installation. The pilot light burner burns with a blue flame which may be conveniently adjusted by means of the needle valve without reference to the other parts of the device, and the burner is so arranged-that it will operate on as low as three-quarters to one cubic foot of gas per hour. Since this burner is burning at all times that the heater is in use, it is essential that it should censume only a small quantity of gas, and that the control mechanism should be sensitive under such conditions. It is also essential that the controller should operate quickly when the pilot light goes out so as to prevent loss of gas. The present construction affords both advantages, and the amount of gas consumed is so small that even though the burner should be extinguished, can escape from it for a long time before a quantity has collected in the heater which would be dangerous.

In the construction illustrated in Fig. 4, the upper end of the burner tube 37 is clamped to the tube 29 by an ordinary twopart clamp 58. In this type of construction the line of orifices 39 extends dowmvardly as at 59, so that these flames impinge directly upon the end of the elbow 4.2. This construction is alternative to that previously described, and either one may be employed as desired. The first constructionis preferred, however, as it insures a direct con-' impinging upon the element housing.

In Fig. 5 there is shown a slightly modified mounting for the burner and controller, and in this type the burner tube 37 is disposed in a bracket 43, extending from the housing of the thermostatic strip, as shown in 1. Extending from the lower part of this housing is a bracket 60 carrying a nozzle tube 61 which may be connected at its lower end to a pipe leading to the supply. The end of the nozzle is spaced from the lower end of the tube 37, and thus gas flowing from the nozzle into the tube induces air with it and by proper regulation of the height of the nozzle with reference to the lower end of the tube, a flame of the desired character may be obtained. In other respects this construction is similar to that previously described. I

In Fig. 6 there is shown a modified form of construction which is designed for great compactness. In this form of controller the valve housing 21 has an opening in its upper end in which is threaded a tube 62. .The

tube terminates at its upper end in a smaller tube 63, the tube 63 terminating atits upper end in a burner of the usual construction, including a row of outlets (i l and a disc 65 above the outlet. Within the tube 62 is a bowed thermostatic element 66, one end of which may be secured in any convenient rigid manner, as by being riveted as at 67, to the valve housing. The free end 68 of the element extends down into the valve chamber and directly attached to it is the ball 69 cooperating with the seat 70. The operationof this form of the controller-is similarto that previously described. hen the pilot light is burning the valve is oil? its seat and permits the flow of gas therethrough. As soon as the pilot light is eX- tinguished, the cooling or" the thermostatic element causes the valve to seat and prevent further flow of gas to the main burner.

In Figs. 7 and 8 are shown piping installations showing the device diagrammatically as it is actually used. In the installation shown in Fig. 7, the main 16 contains the manually operated. shut-oil valve 20, beyond which is a T 71. Beyond this T is the valve operated by the thermostatic elementrwhich enters the tank 1 Beyond the valveli' is the valve 21 from which the line .16 extents to the burner manifold 15. The pilot burner 23 is supplied with gas by a line 72connected at its upper end to the T 71 so that with this arrangement the pilot burner controls the flow of gas by means of a valve placed directly in front of the main burner, but the pilot burner itself receives gas from the main in front of the valve controlled by the thermostatic element exposed to the temperature within the tank, Vith this arrangement the piping is greatly simplified because the line 72 may be of small size and it is not necessary to lead the main supply pipe back upon itself in the manner illustrated in Fig. 2. The installation shownin Fig. 7 may be usedwhen the gas is supplied to the main burner from a main which runs overhead. 7 r

In the construction shown in Fi 8 the 1 t) 7 piping installation is one which may be con- I veniently used when the heater is above the operated valve 20 and the valve controlled by the main thermostatic mechanism, and with the arrangement shown either in Figs. 2, 7, or 8, it will be observed that the pilot burner receives gas from the supply main moaeaa at a point in advance of the valve controlled by the thermostatic element Within the tank. In the constructions shown in 2 and 7, the pilot control mechanism includes a valve which cuts oil the supply of gas prior to its passing through the thermostatically controlled valve 1?, while in the construction shown in Fig. 8, the pilot light controller cuts oil? the gas at a point between the burner and the thermostatically controlled valve 1?. Either arrangementis satisfactory, so long as the pilot burner receives a supply of gas which is in no way fllTQCtGQl by the adjustment-of the valve 17.

it will be observed that in any oi the forms of controller illustrated, the valve actuated by the pilot light controller is moved by a direct connection with the thermostrtic element. This arrangement permits a considerable valve movement which aii'ords easy adjustment and therefore extreme sensitivity of operation. Furthcrn'iorc, the olilicts oi large teinljicrature changes on the element are llflllllll'llZQd. The adjustment of the controller is a simple operation and merely involves the loosening ol. the nut 30 and the turning of the burner and housing as a unit, one or more revolutions. The housing is threaded into the bushing 26 with a line thread. so that a com ilcte revolution of the burner and housing results in only a slight movement of the valve toward its scat, thus permitting close and accurate adjusti'ncnt to be made. The controller is also adaptable for a. wide variety of uses, and it may be arrai'iged For use in any installation, regardless of the direction in which the pilot burner tube is to extend. from the si as main. The burners may be placed in a vertical, horizontal, or inclined position, and by altering the length of the tubes and the llamc track, the requirements of any particular installation may easily be met. lVith this construction the'main burner is so placed that it does not n'iaterially affect the temperature of the thermostatic element, and at. the same time good ignition is provided. liurlhcrmorc, the adjustment oi the blue flame from the pilot is readily made. The valve employed isone in which there is a inclal-to-mclal contact between the seat and the moving part, and the valve is entirely scaled so that the escape o'l. is prevented. There are no joints or connections in which friction will develop, and furthermore no com plicated lever system, such as ordinarily employed in devices ol this cluiractcr, is necessary, owing to the fact that the movable part of the valve is directly connected and moved by the thermostatic element. The spring take-up in the connection bctween the element and the ball of the valve prevents injury of the delicate thermostatic element, and by reason of the absence of the connecting links or pivoted levers,

the parts cannot corrode and thus stick valve, comprising a housing adjustably mounted in the casing of the valve and extending therefrom to a point adjacent the pilot burner, a thermostatic element mounted within the housing and movable therewith as the housing is adjusted with reference to the valve casing, this element being continuously exposed to the temperature developed by the pilot burner flame but outside the zone of temperature produced by the main burnenand a positive connection Within the housing between the element and the valve whereby the element maintains the valve open while the pilot burner is burning and shuts the valve when the pilot burner is extinguished.

2. In a gas heater, a gas supply main,

a main burner receiving gas therefrom, a valve in the main controlling the flow of gas to the main burner and including a casing and seat and a movable part cooperating with the seat, a tube having flame orifices serving as a pilot for the main burner, a housing mounted in the casing of the valve vand having a portion at its end extending at right angles to the axis or the housing, the said portion being conductively connected to the pilot burner tube, a temperature-responsive element within the said portion of the housing and having a part movable to difierent positions in accordance with temperature variations, this element being out of the zone of tempera ture developed by the main burner but receiving heat from the pilot burner, and a connection within the housing extending from the said movable part of the element to the movable part of the valve, the ele ment and the connection being such that the valve is held open while the pilot light is burning and is closed when the pilot burner is extinguished.

3. In a gas heater, a gas supply main, a main burner receiving gas therefrom, a valve for controlling the flow of gas to the main. burner, ahousing connected to the valve, a temperattire-responsive element in the housing, a pilot burner tube lying outside the housing and having flame orifices for directing flames to ignite the main burner, the temperature-responsive element lying outside the zone of temperature de veloped by the main burner, a connection between :the housing and the burner tube for supporting the tube in relation to the housing and also for conducting heat from the burner tube to the housing and element, and a connection between the element and the valve whereby the valve is opened when the pilot burner is-lighted and closed when the pilot burner is extinguished.

a. In gas heater, the combination of a supply main, a heater burner connected to the main, a valve in the main for controlling the flow of gas to the said burner, a pilot burner tube having flame orifices for igniting the main burner, a housing connected to the valve, the pilot burner tube lying outside the housing and being secured thereto and support-ed thereby, a temperature-responsive element Within the housing having a part movable to different positions in accordance with temperature variations, this element being exposed to the temperature developed by the pilot burner but out of the zone of temperature developed by the main burner, a connection between the movable part of this element and the valve such that the valve is open when the pilot burner is lighted and closed when the pilot burner is extinguished, and means for regulating the action of the element on the valve by moving the housing and pilot burner bodily with reference to the valve. I

5. The combination of a gas supply line, a main burner receiving gas therefrom, a valve for controlling the flow of gas to the main burner, a pilot burner for the main burner, and means by which the pilot burner thermostatically controls the operation of said valve, comprising a housing connected to the casing of the valve and also connected to the pilot burner at a point near the flame thereof, the housing serving as a mounting for the pilot burner and receiving heat therefrom conduetively through the connection, a thermostatic element within the housing receiving heat from the pilot burnor but out of the zone of temperature de veloped by the main burner, and a direct connection within the housing between the thermostatieelement and the valve whereby the element acts to hold the valve open while the pilot burner is burning and to close the valve when the pilot burner is extinguished.

6. The combination of a gas supply line, a main burner receiving gas therefrom, a valve for controlling the flow of gas to the main burner, a pilot burner tube receiving gas from the line and having a flame adjacent the main burner to ignite the latter, 7

static element within the housing exposed to the temperature developed by the pilot burner, but out of the zone of temperature "developed by the main burner, anda con- H nection within the housing between the element and the valve, such that the element holds the valve open when the pilot burner is burning but closesthe valve when the pilot burner is extinguished.

7. The combination of a gas supply line,

a main burner receiving gas therefrom, a

valve for controlling the flow of gas to the main burner, a pilot burner tube'receiving gas from the line and having flame orifices adjacent the main burner, and means by which the pilot thermostatically controls'the operation cit the valve, comprising a housing connected to the valve casing, this housing having an angularly disposed end portion, a connection between the burner tube and the housing'by which the housing supports the burner tube, the support providing means for conducting heat developed by the pilot burner to the housing, a thermostatic element within the said end portion of -;the housing having a part movable to different positions in accordance with temperaturevariatiens, this element receiving heat developed by the pilot burner conductively but lying out of the zone of temperature developed by the main burner, and a direct connection within the housing between the valve and the movable part of said element whereby said element maintains the valve open while the pilot burner is lighted, but closes the valve when the pilot burner is extinguished.

8. In combination with a gas heater having a main burner and a pilot burner adapted to thermostatically control the operation of a valve in the gas supply main;

a housing comprising two connected per-'- tions extending at an angle to each other, one of said portions containing the temperature-responsive element and the other portion connecting the first named portion with the casing containing the thermostatiezzily' controlled valve and enclosing the connecting member between the temporalure-responsive element and the valve, said first named portion having a part connecting it to the pilot burner.

9. In a gas heater, the combination of a pilot burner tube, a housing enclosing a temperature-responsive element and a mechaniical connection leading therefrom to a fuel valve of the heater, said element being disposed near the pilot flame issuing from said tube but at :1V distance suflicient to prevent EDXVARD L. F ONSECA.

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