US2362011A

US2362011A - Safety control fob gaseous fuel

Info

Publication number: US2362011A
Authority: US
Publication date: 1944-11-07
Anticipated expiration: 1961-11-07

Description

T. H. JEFF ERS SAFETY CONTROL FOR GASEOUS FUEL BURNERS Filed oct. 31. 1941 s sheets-sheet 1 INVENTOR. Thoma H JfrrfRs.

Nov. 7., 1944.

Nov. 7, 1944.

T. H. JEFFERs 2,362,011

SAFETY CONTROL FOR GASEOUS FUEL BURNERS yFiled Oct. 3l, 1941 3 Sheets-Sheet 2 16 6o a1 1 J2 6210 J4 77? l a4 4s 40 4Z 63 6 54 7d 10a .92 7706 106 124 20 32 3415 28 v 31 90 Y@ 122 11 ZM INLET' INVENTOR. Tnorms l1. JEFFERS.

` 4ATTORNEY Nov. 7', 1944. l T. H. JEFFERs 2,362,011

SAFETY CONTROL FOR GASEOUS FUEL BURNERS Filed Oct. 3l, 1941 5 Sheets-Sheet 3 INVENTOR. 7710MA5 I1.JEFFER\S.

Elm/M A TTORNEY.

Patented New '1, l

OFFICE SAFETY CONTBOL'FGR GASEOUS FUEL i BUBNERS ThomasH. JeffersyLywood, Calif., assignor to Grayson Heat Control, Ltd., Lynwood a corporation of California Appunti@ october s1, 1941, serial Nu. 417,304

12 claims. (ci. 15s-117.1)

This invention relates to safety'devices for gaseous fuel burners and, more particularly, to safety controls intended to shut off the supply offuel to a gas appliance should the pilot burner become accidentally extinguished.

`An objectof the invention is to cause complete and automatic shut-on of all fuel to both the main and pilot burners when the pilot burner becomes extinguished.

Another object of 'the invention is to permit fuel to ilow tothe pilot burner during starting operation while preventing any flow to the main burner. 4

Another object iiow `of fuel to either the main or pilot-burners when theapplianceis unattended unless `the safety device is operative.

Another objectof the inventionis to maintain the pilotV burner in continuous operation, regardless 'of whether or not fuel is flowing to the main burner. 'f

' Another object of the"'invention is to reduce 1 the number of parts by controlling both the main burner and the pilot burner fuel supply by a single valve.

Another object of the-invention is to utilize positive snap-acting means for accomplishing the Another object of` the'invention is to arrange.

the control in compact form as a unitary construction which is adapted for manufacture at lowcost and which will occupy .the minimum of space when installed in the gas appliance.

Other objects and advantages will become apparent from the following description taken in connection .withA the accompanying drawings,

wherein: v a

Fig. l is mend elevation of the safety control; Fig. 2 .is a section taken on the line 2`2 of Fig. 1 looking in ther-direction indicatedv by the arrows;

Fig. c is a' sectional but semi-developed vviw illustrating the location' of the various parts vin relation to the pathof travel of the fuel through the control; Y s

Fig. .f4 is a partial section'taken on the line l-l -of Fig. 1 looking in the direction indicated lliig.'lisapartialsectionc :orrespondingto'll'il. s beof the rod-and-tube-type having atube Il of the inventionA is to prevent I section taken on the line 4 but showing the main control valve ina different position; f

Fig. 8 is a. partial section corresponding to Fig. 5 but showing the main control valve in a different 5 positiom. Fig. 9 is a partial section corresponding to Fig.

6 but showing the main control valve in a diierent position;

Fig. 10 is a cross-section through the controlv 1 0 showninFlg. 1;

. Fig. 11 is a plan view of the dial;

Figs. 12 and 13 are geometrical developments of the seating surfaces of the main control valve.

Referring more particularly to the drawings, the control device comprises a casing Il) having an inlet I2 in one side thereof communicating with a centrally disposed chamberl Il extending 'substantially perpendicular 'to the inlet. The upper'portion of the chamber Il'is threaded for the reception of a cap I6 which serves to close the'. open enduit the chamber.

A valve seat memlber Il is positioned within the chamber I4. The valve seat member is genof the chamber Il below the cap I6 and an unthreaded portion closely fitted withinthe lower portion of .the chamber Il with its bottom face `seated upon the bottom portion 20 of the chamber.l

A recess 22 is provided in the bottom face of the valve seat member I8 and an annular knife-- edge portion 24 projects inwardly thereof to form a seat for .a snap disc`26. The snap disc is smaller in diameter than `the recess 22 and as- 'sumes a convex form, as in Fig. 3, when free. 'Ihe disc is supported in the recess 22 by a. thrust element 28 provided on one face with an annular lmife-edgeportion 3 0 similar to the portion 24.

40 In this embodiment, the knife-edge 24 is smaller in diameter than the knife-edge 3|! and is thus positioned inwardly thereof with respect to thedisc 28 to provide the necessary leverage for operation. When pressure of the thrust element 28 is relieved the snap disc tends to force its center portion away fromthe thrust element to form the convex curve mentioned, `ths being inthe opposite positiontothatahown inFig.2., Thedisc 28 andthmstmember 2l areslidably 50. supportedwithintheuece'ssnandreceiveaxial ,I

thrust from the rounded end I I of the rod por--Vv tion l2 of a thermally responsive element, causing the disc 2t to assume'the psition strown'in 113.2. Thethermally ve element may erally cylindrical in form having a n upperv threaded portion engaging the threaded pcrtion of material having a high coefficient of expansion and the rod 32 having a. relatively lower coeicient of expansion. The rod 32 is supported at each end in recesses formed in the thrust element 28 and tube 34. The element is supported from the casing I by the tube portion which threadedly engages a projection 36 thereon and is secured by means of the lock nut 38.

The valve seat member I8 is provided with an annular opening 48 therein extending from the upper e d thereof and terminating adjacent the recess 2. A plurality of apertures 42 extend transversely through the wall of the valve seat member I8 intermediate its ends and ailord communication between the annular passage 48 and the chamber I4. A pair of oppositely disposed holes 45 may -be formed in the end wall between the opening 48 and the recess 22 for the reception of a tool for inserting the valve seat member I8 in position.

An annular projection is formed on the upper surface of the valve seat member I8 and serves as a valve seat 44 for a safety valve member 48. The safety valve 46 is adapted to control the passage of fuel between the chamber` I4 and the apertures 42 in the valve seat member by movement toward and away from its seat 44. To this end, the safety valve 46 is provided with a valve stem 48 slidably engaging an axial opening 48 in the valve seat member I8 and carrying a threaded projection 58. The projection 58 engages the snap disc 25 at its central portion on the side opposite the thrust element 32 and is adjustable with respect thereto 'due to its threaded engagement with-the valve stem. A coil spring 52 extends between the safety valve 46 and the underside of the cap I8 and assists the valve member 46 in returning to its seat when the snap disc 28 permits. It will be understood that the snap disc 26 is capable of opening the safety valve 48 against the force of the fuel pressure isn the chamber I4 and the force of the spring A tapered valve seat 54 is formed in the casing I8 substantially perpendicular to the chamber I4 with which it communicates at its smaller end by means of a passage 58 between the valve seat member I8 and the smaller end. Intersectingr the tapered valve seat 54 intermediate its ends is an outlet 58 which extends through the casing on the side opposite the inlet I2. `its will be clear from Fig. 10 the inlet I2 andv outlet 58 are in different horizontal planes and there is no communication between the inlet and the passage 56 except by way of the safety valve chamber I4. Engaging with the tapered valve seat 54 is a tapered plug cock or main control valve 68 having an axial opening 62 extending from the smaller end thereof and communicating. with a transverse port 84 extending through one side thereof intermediate the ends. 'I'he axial opening 52 is in communication with the passage 58 in the casing I8 and the port 84 is adapted to establish communication between the opening-52 and the outlet 58- when the plug cock is rotated to certain position in its seat 54.

The plug cock or main control valve 88 is held yieldably against its seat by,a spring $8 housed within a recess in the upper end thereof and en Saging with a retainer plate 88 secured to the casing lII as by means of the screws 18. An operating stem 'I2 projects from the upper end of the main `control valve 88 and is provided with an operating handle in the form of a dial 14 xedly secured thereto and providing means by which the valve 68 may be rotated in its seat 54.

In order to limit rotation of the valve 68 to substantially the retainer 68 is provided with a projection 'I8 extending perpendicular thereto and received within a groove 'I8 of arcuate form in the underside of the dial 'I4. The arcuate groove 'I8 is lmade of sufcient length to permit the specified amount of rotation of the valve 68 and the projection 16 forms a stop which will engage with either end of the groove to limit such rotation. The face of the dial 'I4 is provided with suitable indicia for fon, pilot only" and off" positions which are adapted to be aligned with a n'otch I5 for-med in the casing I8 adjacent the retainer. The groove 'I8 is arranged to limit the rotation of the valve 68 between the on and off positions by engagement with the stop 16. At the pilot only" position a non-positive stop is provided. This stop is in the form of a plunger 8| yieldably mounted within the dial 'I4 and projecting from the underside thereof into engagement with the retainer 88. At the pilot only" position the end of the plunger 8| drops into a depression formed in the retainer 68 with an audible click. Furthermore, the plunger 8| adds a noticeable resistance to the rotation of the dial when moved from the pilot only position.

'The safety valve of this invention not only prov vides control of the fuel passing through the outlet 58 to themain burner but also provides control -ofthe passage of fuel to a pilot burner incorporated in the control. Accordingly, a passage 88 is formed in the casing communicating with the tapered valve seat 54 of the main control valve or plug cock 68. At the junction of the passage 88 with the valve seat 54 is an elongated slot 82 formed in the casing and extending partly on each side of the passage 88 around the valve seat 54 for a short distance. The slot 82 is adapted to register with a groove 84 in the valve 68 extending tangentially from one end of the port 84 through the wall of the valve and affording communication between the slot 84 and the passage The other end of the passage 88 in the casing I0 communicates with a bore 86 formed in the casing and within which a pilot adjusting member 88 is rotatably mounted'. 'I'he upper end of the pilot adjusting member 88 projects into an enlarged portion of the bore 86 at the exterior of the housing I0 and is provided with a slot 88 by means of which the member may be rotated in the bore. The enlargement may be threaded for the reception of a closure capv 82 whichis removable for obtaining access to the pilot adjusting member 88 when required. A T-shaped opening 94 is formed in the lower end of the pilot adjusting member 88 and establishes communication between the passage 88 and a passage 88 in the housing leading to a threaded connection 98 for a pilot burner |88. The pilot burner I88 extends from the housing I8v substantially p arallel with and adjacentv to the thermally responsive element .34 so that the terminal end of this element will be heated by the pilot flame.

It will be observed that passage of fuel to the pilot burner |88 can Ibe obtained. from the 'inlet I2 when the groove 84 registers with the passage 3 0. and the safety valve 48 is opened. In orde'r to provide for passage of fuel to the pilot burner |88 when the safety valve 46 is closed, such as for starting purposes, a by-pass is provided in this asseoir.

to valve `seat I4' of the main control valve orplug cockv C. The Junction af fthe passage |02 with the valve seat 54 is in longitudinal alignment with the junction of the passage l therewith and these passages are spaced in suchrelationship that both are within the margin of thel port 04 when in registry therewith.

is controlled by a manually operated pilotcontrol c valve carried .by the casing. The pilot control valve may comprise a valve head |04 provided with a stem |00 projecting from the casing |0 move the outer end thereofslightly toward the right as viewed in Fig. 2. Due to the lower coeilicient of expansion of the rod portion 02 the pres- 'I'he passage of fuel through the by-Dss |02 y and carrying a button |00 by means of which it valve head |04 and the closure cap||4 and serves v.

pered valveseat 54 of the main control valve .or plug cock 00. Upon release of manual pressure upon the button |08 the spring |8 will return the valve head |04 to its seat and close the by-pass passage. y

The operation of the device is` as follows: Fuel from the inlet |2 is contained in the safety valve chamber I4l above the safety valve 46 which is in closed position in engagement with the seat 44.

the fuel yline ahead of the control described herein which is normally left open and forms no part of the present invention. However, should itbe Vdesired to remove the closure cap I6 to clean or repair the safety valve assembly then the fuel line shut-,off cock would be closed as a preliminary operation.

Assuming that the fuel is flowing through the inlet as described, the dial 'i4 of the main control valve'is rotated to pilot onlyf@ position yand the button |00 is depressed to operate the pilot control valve. This permits fuelto. flow from the inlet |2 through passage |02 and past the pilot control valve head |04 to the main control valve ,seat 54. As the main control valve` is inl ilot only position the port B4 therein. is in registry .with the-passage |02 aswell as the passage 00, as shown .in Figs. 4-6 inclusive. As the outlet 58 to the main" burner is not in registry at thios time with the passage 82 there'isno exit for the fuel entering the: passage 02 except through-the passage' 80. V Fuel then flows `through the latter passage 00 to passage 90 in an amount controlled.

by the adjustment of the pilot adjustment member 80'. The fuel flowing from the pilot burner tip is then ignited with a match or other suitable means.' The flame is arranged to impinge properly on the outer endof the tube element 34,

as familiar to those skilled in the art, byadjustment. of the pilot adjustment member 0'8.

After the button |08 has been depressed for burner flame heats the thermal element 'sufficiently 'to expand the tube portion 34 thereof and 75 extinguished. It gnu be apparent'tha't even if other leg of the angular passage |02 to the ta- Ordinarily,..there is provided a shut-off cock in sure thereof on the thrust element -20 -is relieved.'

thus removing the thrust exerted by the latter upon the snap disc 20. Hence, the snap disc!! finally snaps over center to its normal position as shown inFig. 3. The movement of the snap disc 20 actuates the threaded element l0 to move the safety valve 40 oif the valve seat 44 against the pressure' of the 'fuel in chamber I4 and the spring' 02.

Upon opening of the safety valve 40 fuel may flow through the passage I0 into the axial open-` ing 02 of the main control valve l0. Puel also passes through the port. and the passage Il f- Vto the pilot burner instead of being by-passed from the inlet I2 around the safety valve 4l as was the c'ase before this valve was opened. Thus, the release of the button |00 to close thev pilot control valve after the safety opens does not cut oif the flow of fuel to the pilot burner but merely closes the by-pass passage from the inlet I2. The main control valve is then rotated to the on" position shown on the dial :14 as limited by the stop 16. Inl'this position the port 64 registers with .the outlet 50, as shown in Figs. 7-9 inclusive, and permits fuel to dow to the main burner to be ignited at that point. 'Ihe supply of fuel, however, is not cut offV to the pilot-burner due to the provision of thel groove 04 in the main control valve 00 which connects the axial opening 020 therein with the elongated slot l2 of the passage00. It will be' observed that the passage |02 is at this time closed offV by the surface of the main control valve 00.

Should the pilot burner flame become extin-` A guished when the main burner is operating under control of the safety valve as described. the cooling of'the thermally responsive unit 24 would cause reversal of the position of the snap disc 26 and immediate closing of the safety valve 40. As both the main and pilot burners are at auch time being supplied with fuel by way of the "passage 56 under control of the safety-valve, no

further fuel would flow to either burner. Thus, a complete shut-off of fuel is obtained'iipon operation of the safety valve'.

The main burner may be turned off and the pilot flame .left burning by rotation of the main control valve dial from, the on" toAthe "pilot only position. Both burners mayf be extinguished and the appliance rendered inoperative by rotating the dial to the "oi'f" position. In

this position', theport 84 is diametrically op-` posite the outlet which is thus closed and the by-pass passages 02 and 80 are also closed of! by the surface of the maincontrol valve l0.

In the on position of the main control valve dial the 'oy-pass passage |02is closed and manual pressure on the button |00 could not by-pass fuell around the safety'valve in this position. Thus, no fuel can be made to flow to the main burner until the pilot burner has been lighted a short period, usually two minutes,` the pilot.

a sufllcient time to cause opening of the safety 'valve as described` When theappliance is left unattended no fuel can ow to either burner unless` the safety valve has previously 'been brought into operation to shut oil' the fuel supply should the pilot burner beeome' extinguished.

yL'l'he pilot `control valve provides means.- for preventing supply of fuel to the pilotbsurner in the event that the main control valve is left in "pilot onlybposition and the pilot flame becomes burners, a main control valve having a port adapted to communicate with said passage, separate outlets for fuel to the burners under control of said main control valve, said main control valve being adjustable to a position permitting flow ofi-fuel through said port and one of said `outlets to the pilot burner when the safety valve is in closed position and preventing flow of fuel.

to the main burner in said position, means communicating with said port and said one outlet for by-passing fuel around said safety valve to the pilot burner when the main control valve is in said position, and means responsive to the presence of a ame at the pilot burner for opening the safety valve for flow of fuel through f said common passage and through said port and said one outlet to the pilot burner instead of by way of the by-pass while said main control valve remains in said position.

-2.A safety control 'for gaseous fuel burners having main and pilot burners, comprising in combination, a safety valve controlling a common passage for fuel to both the main and pilot burners, a main control valve having a port adapted to communicate with said passage, separate outlets for fuel to the burners under control of said main control valve, said main control valve'being adjustable to a position permitting 'flow of fuel through said port and one of said outlets to the pilot burner when the safety valve is in closed position and preventing` flow of fuel to the main burner in said position, means communicating with said port and said oneoutlet for by-passing fuelv around said safety valve to the pilot burner when the main control valve is in said position, a manually operated auxiliary valve movable between`positi0ns for controlling the passage of said by-passed fuel and being biased to a closed position, and means responsive to the presence of a flame at the 'pilot burner for opening the safety valve for flow of fuel through said common passage4 and through said port andl said one outletvto the pilot burner instead of by way of the by-pass while said main control valve remains in said position, whereby said auxiliary valve-may be closed under said bias thereof.

3. A safetyfcontrol for gaseous fuel burners having main and pilot burners, comprising in combination, la safety valve controlling a common passage for fuel to both the main and pilot burners, a main control valve having a port adapted to -communicate with said passage,

with said port and said one outlet for oy-passing fuel around said safety valve to the pilot burner when the main control valve is in the rst said position, and means responsive to the presence of a flame at the pilot burner for opening the safety valve for flow of fuel through said common passage and through said port and said one outlet to the pilot burner instead of by way of the by-pass while the main control valve remains in first said position.

4. A safety control for gaseous fuel burners having main and pilot burners, comprising in combination, a casing having an inlet for fuel and separate outlets therefor leading to the main and pilot burners, a valve seat dividing said inlet from -said outlets, a safety valve engageable with said seat for controlling flow of fuel from said inlet through said outlets to both the main and pilot burners, a main control valve between said safety valve and outlets having a port therein, said main control valve being movable to a position permitting the passage of fuel from the safety valve through said outlets and said port to both the main v.and pilot burners, a by-pass passage in said casing providing communication through said port and one of said outlets between said inlet and the pilot burner when the safety valve is closed and said main control valve is moved to another position, and means responsive to the presence of a flame at the pilot burner for opening the safety valve, said port being positioned out of communication with said by-pass passage when the main control valve is thereafter moved to the first said position. i

5. A safety control for gaseous fuel burner having main and pilot burners, comprising in separate outlets for fuel to the burners under I control of said main control valve, said main control valve being adjustable to a position for permitting flow of fuel through said port and one of said outlets to the pilot burner when the safety valve is in closed position and preventing` flow of fuel to the main burner in said position, said main control valve'being adjustable to another. position permitting flow of fuel through said common passage and said port and outlets to both-main and pilot burners when the safety valve is in open position, means communicating combination, a casing having an inlet for fuel and an outlet therefor to the main burner, a safety valve controlling lthe passage of fuel between the inlet and outlet, a main control valve in said casing between said safety valve and the outlet and adjustable between off and on" positions to control the passage of fuel therebetween, a duct in said casing communicating with said inlet and the pilot burner for by-passing fuel around said safety valve to said pilot burner, said duct being controlled by said main control valve, and means responsive to the presence of a flame at the pilot burner for opening said safety valve for passage of fuel to both the main and 4pilot burners when said main control valve is adjusted to said on position.

6. A safety control for gaseous fuel burners having main and pilot burners, comprising in combination, a casing having an inlet for fuel tion of the main control valve for conducting fuelto the pilot burner when the safety valve is closed, and means responsive to the presence of a flame at the pilot burner for opening the safety valve for passage of fuel therethrough to said pilot burner while the main controlvalve remains in said intermediate position.

7. A safety control for gaseous fuel burners having main and'pilot burners, comprising in.

combination, a casing havingan inlet for fuel and an outlet therefor to the main burner, a safety valve controlling the passage of fuel between the inlet and outlet, a main control valve insaid casing `:between said safety valve and the outlet, means for adjusting said main control valve between offl and on positions anda position intermediate thereto, said main control valve being adapted to permit the passage of-fuel from the safety valve to both4 the main and pilot burners when in said on position and to the pilot burner only when in said intermediate position,- means operable in said intermediate position of the main control valve for conducting fuel to the pilot burner when thesfty valve is closed, and

sage of fuel to both thevmain and pilot burners,

a main control valve having a chamber therein providing a passage for fuel from said safety valve, means for establishing communication between said chamber and both the main and pilot burners when the safety valve is in open position, and means for by-passing fuel through said chamber to the pilot burner only, when the safety valve is in closed position.

valve to close the rst said duct from communi- 9. A safety control for gaseous fuel burners having main and pilot burners, comprising Iin combination, a safety valve controlling the passage of fuel to both the main and pilot burners, a main control valve movable between positions and having a chamber therein providing a passage for fuel from said safety valve, a port in said p main control valve providing in one of said pohaving main and pilot burners, comprising in combination, a casing having an inlet for fuel and an outlet therefor leading to the main and pilot burners, a safety valve controlling the passage of fuel from said inlet, a main control valve `having a port movable therewith into and out ofregistry with said outlet to control the passage of fuel from said safety valve, a by-pass passage Ain'said casing providing communication between said inlet and the pilot burner when said safetyvalve is closed, manual means for `moving said main control valve to a position to open said bypass for passage of fuel to said pilot burner, and means responsive to the presence of; al flame at the pilot burner for openingthe safety valve, said manual means being operable for'inoving said main control valve to another position for-closing said by-pass and simultaneously establishing communication between said port and the outlet for passage of fuel from the inlet to both main and pilot burners.

1l. A safety control for gaseous fuel burners having main and pilot burners, comprising in combination, a Acasing having an inlet for fuel,

and an outlet therefor 'to the main burner, a safety valve controlling the passage of fuel between the inlet and outlet, a main control valve in said casing between the safety valve and the outlet having an axial opening providing a passage for fuel from said safety valve, a transverse port in said main control valve communicating with said opening and the outlet, a duct in said casing communicating with said inlet and said port when the main control valve is in one position, a second duct in said casing communicating with said pilot burner and said port when said main control valve is.in said position, said ducts providing passage for fuel from the inlet to the pilot burner when the safety valve is closed, means for opening said safety valve when said main control valve is in said position for passage of fuel therefrom through said second duct to said pilot burner, and means on said main control cation with said port while retaining communication -with said second duct upon movement thereof to another position.

l2. A safety control for gaseous fuel burners having main and pilot burners, comprising in combination, a casing having an inlet for fuel and an outlet therefor leading to the main burner, a safety valve controlling the passage of fuel between said inlet and outlet, a main control valve in said casing between the safety valveand the outlet having a chamber for fuel from said safety valve, a port in said main control valve communieating with said chamber and the outlet, a duct in said casing'communicating with said inlet land said port when the main control valve is in one positio'm a second duct in said casing communieating with said pilot burner and said port when said main' control valve is in said position, saidducts providing passage for fuel-from the inlet to the pilot burner when the safety valve is closed.

manual means for moving said main control valve 'to said position, means responsive to/ the pres- `ence of a name at the pilot burner whten the main control valve is in said .position for opening the safety valve, and means on said main control valve to close -the first said ductfrom communication with saidport while establishing communication with said outlet and the second duct upon operation of said manual means to move4 said valve to another position.