US1874501A - of lynwood - Google Patents

Description

Filed Jan. 24. 1931 Patented Aug. 30, 1932 UNITED STATES PATENT? OFFICE JOI-IN H. GRAYSON, OF LYNWOOD, CALIFORNIA, ASSIGNOR TO GRAYSON HEAT CONTROL, INC., OF LYNWOOD, CALIFORNIA, A CORPORATION OF CALIFORNIA SAFETY PILOT Ges cocx Application led January 24, 1931.

This invention relates to gas appliances generally, and is particularly concerned with a safety pilot gas cock.

Safety devices for gas appliances have invariably been of extremely complicated and expensive construction and more or less impractical for most purposes. Frequently, too, such devices have not been as positive in operation as desired and would not, therefore, meet with the approval of underwriters. There was also the objection that in many cases the safety device took care of the shutting olf of the gas only to the main burner in the event the pilot burner was extinguished. It is, therefore, the principal object of my invention to provide a simple and inexpensive safety device which is absolutely positive in its operation and affords a complete shut-oif of the gas to the main burner and its pilot burner in the event of extinguishment of the pilot light.

Another object is to construct the safety device as part of a unitary assembly with the manually operable gas shut-off cock. More specifically stated, I provide a tube slidable in a longitudinal bore in the turn plug of the cock carrying the pilot burner thereon. the tube serving normally to conduct gas from the cock to the burner, but being movable by a thermostat to a' position where it closes the hole. in the plug when the pilot light is eX- tinguished, thus shutting off the gas to both burners simultaneously. The thermostat is supported on a bracket on the body of the cock in juxtaposition to the pilot burner and so long as it is heated by the pilot light serves to hold the tube in retracted position with reference to the hole in the plug. The thermostat also has such an operating connection with the tube to hold it against turning with the plug, so that the pilot burner is maintained in a predetermined position in proper relation to the thermostat and burner with which it is supposed to cooperate.

The invention will be better understood as reference is made in the following specification to the accompanying. drawing, in Whi-ch- Figure 1 is a fragmentary vertical sectio 50 through a water heater equipped with a Serial No. 510,886.

safety pilot gas cock made in accordance with my invention;

Figs. 2 and 3 are vertical and horizontal sections, respectively, on the correspondingly numered lines of Figure 1;

Fig. 4 is a fragmentary vertical sectional detail of a portion of Fig. 2;

Fig. 5 is a vertical sectional detail on the l1ne5--5 of Fig. 2 on an enlarged scale, and

Fig. 6 is a vertical sectional detail illustrating another feature of the gas cock.

The same reference numerals are applied to corresponding parts throughout the views. The invention is herein illustrated as applied to a water heater, but it should be understood that it is applicable to various gas appliances wherever a pilot burner is used in connection with a main burner. In Figure 1, the numeral 10 is applied to the tank of a water heater in the lower end of which is the usual heating or combustion chamber 11 below the bottom 12. A flue, the lower end of which appears at 13, serves to carry off the waste products of combustion. A plate 14 closes the bottom of the chamber 11 except for a central opening 15 through which air is admitted to support combustion, and, of course, theusual legs 16 are provided to support the heater at the proper elevation with respect to the floor. The burner shown at 17 is like that illustrated in my copending application, Serial No. 510,075 led January 21, 1931 and has a valve 18 and thermostat 19 constructed as parts of a unitary assembly therewith, as described in said application. The valve 18 is of a snap-action type, and' when opened, establishes direct communication with the burner 17 for the delivery of gas thereto, the gas being supplied through pipe 20. The valve 18, in accordance with said application, is opened and closed under v the control of the thermostat 19 for the purloo generally by the reference numeral 22, which cooperates with thc burner 17 and the valve 18 provided in connection therewith.

The safety pilot gas cock 22 comprises a body 23 connected at one end with the gas supply pipe 20, as at 24, and suitably threaded at its other end in the body of the valve 18. A turn plug 25 has a close working fit in the tapered bore 26 in the body 23 and is arranged to be turned by hand by means of the handle 27 to bring the transverse hole 28 in the plug into and out of communication with the passage 29 provided in the body. The plug 25 is, therefore, a means for shutting off the gas, as for example, when it is desired to dispensewith the heating of water for acertain period of time. A coiled comression spring 30 compressed between the ody 23 and lock nuts 31 threaded on the projecting end of the plug 25 holds the plug under the desired tension to prevent leakage of gas about the same. The plug 25 has a longitudinal bore 32 drilled therein from the small end thereof and intersecting the hole 28 and terminating at a pointslightly beyond said hole, as clearly appears in the drawing. The bore 32 is at least as large in diameter as the hole 28 and preferably a little larger so that the tube 33, which has a close working fit in said bore, is brought to the positionl shown in Fig. 3 to close the hole and reventI the low of gas through the cock from t e pipe- 20 to the valve 18. A ring 34 is suitably se- 4cured on the outer end of the tube 33, as by sweat soldering the same thereon, and a tube 35 is threaded in this ring and projects upwardly therefrom and carries a pilot burner tip 36 on its upper end. A small hole 37 is drilled radially through the wall of the tube 33 nearit-s outer end to establish communication between the longitudinal bore 38 in the tube 33 and the longitudinal bore in the tube 35. Thus, when the tube 33 is retracted with reference to the hole 28, the pilot burnerA isl supplied with gas through the tubes 33 and 35. The tube 33 occupies a retracted position, so lon as the pilot light is not extinguished, as wil soon appear. A scre w 39 is threaded in the outer end of the bore 38 of the tube 33 to regulate the flow of gas to the pilot burner, as desired, so as to conserve in the use of gas for the pilot light. A cap 40 is removably threaded on the end of the tube 33 and covers up the head of the screw. Now, a bimetallic thermostat 41 is supported in juxtaposition to the burner 36 by means of a bracket 42 fastened on the body 23 of the cock 22, as appears at 43. The thermostat is suitably secured at its upper end to the upper end of the bracket 42 by screws 44, and has the free lower end thereof forked, as appears at 45, for reception in slots 46 formed in the opposite sides" of the tube 33. The bottoms of the slots afford flats 47 on the tube, and the forked end of the thermostat cooperates with these flats,

as appears in Fig. 5, to hold the tube 33 against turning in the plug 25, thus keeping the pilot burner 36 in a predetermined position with relation to the burner 17 with which it is supposed to cooperate, and allowing the 7 plug 25 to be turned with respect to it. The thermostat 41 is made in two portions 48 and 49, the former being of invar or some other metal showing little or no expansion or contraction with temperature change, and the latter of any suitable expansible alloy. It will be observed that the portion 48 is on the side toward the burner 36 so that when the thermostat is heated by the pilot light, the expansion of the portion 49 causes the deiecso tion of the thermostat, as indicated in dotted lines inlFig. 2, thereby moving the tube 33 to retracted position with respect to the hole 28 in the plug 25.

In operation, when the pilot burner is to be lit, the thermostat 41 has to be flexed by hand to the dotted line position shown in Fig. 2, so as to take care of the delivery of gas to the pilot burner by Way of the tube 33. The pilot light heats the thermostat and keeps it 9 flexed. In that way it is obvious that the/ heating of the thermostat by the pilot light is the thing that controls the delivery of gas through the cock 22 to the burner 17 and pilot burner 36. Should the pilot light be extin- 95 guished, as for example, yby a sudden gust of air striking the -water heater, or due to any other causes, such as air in the gas line, the thermostat 41 cools off and changes from the v condition indicated in dotted lines in Fig. 2 1' to the condition shown in full lines. That is, it straightens out from its flexed condition thereby movin the tube 33 inwardly and finally, when t e tube reaches the position shown in Fig. 3, shutting off the flow of gas to both burners simultaneously. The heater can then be thrown into operation again only by the-relighting of the pilot burner in the manner described. If the heater is to be shut oif for a certain len th of time, the plug n. 25 can be turned by han to bring the hole -28 out of register with the passage 29 in the cock 22. This, of course, shuts oif the gas to both burners simultaneously.

It should be evident from the foregoing description that I have provided a safety device of an extremely simple and inexpensive construction, and one which isvery compact, being constructed as part of a unitary assembly with the shut-off cock 22 and, moreover, 12

" as part of a unitary assembly with the burner 17 and its control valve 18 and thermostat 19. It requires very little work to install the unit, there being but a single pipe connection to take care of, that being t-he connection of the pipe 20 with the cock 22.

In conclusion, attention is called to Fig. 6, disclosing the adjustable plug 50 threaded in a boss 5l formed integral with the body 23 4of the cock at an intermediate point of the 130 ture change,

l and serving invasor passage 29 between the plug 25 and the burner 17. This plug is arranged to be adjusted according to the available gas pressure so that the burner 17 will operate most eiiiciently. A cap 52 threading on the boss 51 seals the plug 50 to keep it from being tampered with. Obviously, once the plug is adjusted, there is usually no need for making a change 4in the setting.

lt is believed the foregoing description conveys a good understanding of all of the objects and advantages of my invention. Obviously, various changes might be made without departing 'from the spirit and scope of the invention. Thus, the tube 33, while not so designated in the foregoing description, should naturally be looked upon as a valve or plug whose movement with reference to the gas supply passage 28-29 controls the gas dow. The appended claims have been drawn with a view to covering all legitimate modiications and adaptations.

l claim:

1. ln a gas iow controlling device, the combination oiI a valve body having a passage therein for the iiow of gas therethrough, a plug slidable in a transverse bore in said body toward and away from said passage and operable to close the latter to stop gas flow through the body, a gas burner mounted on the outer end of said plug, said plug having a passage therein normally establising communicatipn between the aforesaid passage in the body and the burner, a bracket rigid with said body, and an elongated thermostat fixed at one end to said bracket in juxtaposition to the burner whereby to be heated in the operation thereof, the other end of said thermostat being free to move in the deflection of the thermostat with temperathe movable end of said thermostat being directly connected with said plug to hold the plug in retracted position relative to the passage in said body so long as the thermostat remains heated, but operable to move the plug into a position closing said passage in the event of cooling of the thermostat.

2. A device as set forth in claim l wherein the thermostat is so connected with the plug that the latter is held against turning out of a predetermined position, whereby to hold the burner in a predetermined position relative to the thermostat.

3. A device as set forth in claim l including means for regulating the flow of gas through the passage in the plug.

4. A device as set forth in claim 1 including a turn plug rotatably received in the valve body concentric with the slidable plug and providing a bore therein for reception of said plug, said turn plug having a transverse hole therein positioned to register with the passage in the valve body, said turn plu being operable to be turned to stop gas ow t ough said passage independently of the slidable plug, whereby to shut oli gas dow to said burner through the slidable plug.

5. A device as set forth in claim l including a turn plug body concentric with the slidable plug and providing a bore therein for reception of said plug, said turn plug having a transverse hole therein positioned to register with the passage in the valve body, being operable to be turned to stop gas dow through said passage independently of the slidable plug, whereby to shut od' gas dow to said burner through the slidable plug, and

j wherein the thermostat is so connected with the slidable plug as to hold the latter against turning with the turn plug whereby to keep the burner in a predetermined position relative to the thermostat. v

G. A safety pilot gas cock comprising a body member having a passage therein for the iow ol' gas therethrough, a tube slidable in a transverse bore in said body toward and away from the passage and operable to close the latter, a pilot burner mounted on and project-ing vertically Jirom the outer end of said tube, the said burner being normally placed in communication with said passage through said tube, a bracket rigid with said body member and projecting upwardly therefrom, and an elongated thermostat rigid at its upper end with the bracket and extending downwardly in juxtaposition to the pilot burner and having its lower end free to move in the deflection of the thermostat with temperature change, the lower end of said thermostat being connected with the tube and serving to hold the latter against turning whereby to maintain the pilot burner in proper relation to the thermostat, said thermostat being operable while heated to hold the tube in retracted position relative to the passage in said body but being operable when cooled to move the tube inwardly to a position closingn said passage.

7. i safety pilot gas cock as set forth in claim 6 including a turn plug rotatably mounted in the body in concentric relation to the slidable tube and providing a bore therein for reception of the tube, said turn plug having a transverse hole therein positioned to register with the passage in the body but belng operable to be turned to close the passage independently of the tube whereby to also shut oft' gas iiow to the pilot burner through said tube.

8. A safety pilot gas cock as set forth in claim G'including a pressure regulating plug mounted in the body for adjustment toward and away from the passage therein, said plug serving when adjustedto allowonly a. predetermined ow of gas through the passage.

In witness of the foregoing I aiix my signature.

JOHN H. p GRAYSON.

rotatably received in the valve said turn plug

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