US2478496A

US2478496A - Thermostatic safety burner control

Info

Publication number: US2478496A
Authority: US
Publication date: 1949-08-09
Anticipated expiration: 1966-08-09

Description

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J. MAYNARD 'I'HEBMOS-TAIIC SAFETY BURNER CONTROL Filed D60. 29, 1945 Aug. 9, 1949.

M Wm M mym o NA Er 5M T v m A Ns M 1 w 1 MK m v H engaging the pilot valve.

Patented Aug. 9, 1949 2,478,496 I 'rnmmos'mrrc SAFETY BURNER CONTROL James Maynard, Hawthorne, Calll'., assignor to Elg'ln Rowland Parker, Compton, Calif.

Application December 29, 1945, Serial No. 638,112

1 5 Claims. (01. 1ss 117.1)

'naces, stoves and the like to prevent the escape of fuel in the event that the pilot flame'is extinguished for any reason.

A primary object of my invention is the provision of a thermostatically controlled safety device or safety valve which is adapted for controlling the flow of fuel to the main and pilot burners of the heating apparatus and is adapted for terminating the flow of fuel to both the main burner and the pilot burner automatically whenever the pilot flame is extinguished.

Another object of my invention is the provision of a device of this general character which includes a valve body having a main valve and a pilot valve associated therewith to control the flow of fuel to the main and pilot burners, respectively. Another object in this connection is the provision of a safety device having a valve bodywhich includes the pilot burner.

A further object of my invention is the provision of a safety device which employs a. single thermostatic means or element for controlling the positions of both the main valve and the pilot valve, the thermostatic element being mounted on the pilot burner and being disposed adjacent the pilot flame.

Still another object is the provision of mechanical means which may be operated by the thermostatic element to control the positions of the main and pilot valves. Another object in this connection is to provide mechanical means ineluding a reciprocable operating member and a rotatable actuating member, the operating member being operatively engaged by the thermostatic element and operatively engaging the main valve, and the actuating member being operatively engaged by the operating member and operatively Still another object in this connection is the provision of an actuating member which is manually operable to open the pilot valve when it is necessary to ignite or reignite the fuel at the pilot burner to provide the pilot flame.

An additional object of my invention is the provision of a safety device which includes resilient means for urging the main valve toward an open position, and which includes resilient means for urging the pilot valve toward a closed position.

Another object of my invention is to provide a safety device including main and pilot valves, a pilot burner, and thermostatic means for controlling the valves as an integral unit which may be mounted on conventional heating equipment filllgch as water heaters, furnaces, ovens, and the An important object is the provision of a safety device which is adapted to operate in a relatively simple, sensitive, and reliable manner for extended intervals of time with little or no attention or maintenance.

The foregoing objects of my invention, together with various other objects and various advantages which will appear evident hereinafter, may be realized by means of -the exemplary embodiment which is described in detail hereinafter and is illustrated in the accompanying drawing. Referring to the drawing, which is intended as illustrative only:

Fig. 1 is an elevational view of a safety device or safety valve which embodies the fundamental principles of my invention;

Fig. 2 is a sectional view thereof which is taken along the broken line 2-2 of Fig. 1; and

Fig. 3 is another sectional view thereof which is taken as indicated by the broken line 3-3 of Fig. 2.

Referring to the drawing, the safety device includes a valve body which is generally indicated by the numeral ill, the valve body including a main valve body ll having a main passage l2 therethrough and having a main valve chamber l3 therein which communicates with the main passage. A main valve I4 is disposed in the main valve chamber I3 and is reciprocable therein along an axis A-A as will be described in detail hereinafter. The valve body I0 also includes a pilot valve body 16 which is provided with a pilot passage l1 therethrough and is provided with a pilot valve chamber l8 therein which communicates with the pilot passage, a pilot valve l9 being disposed in the pilot valve chamber and being reciprocable therein along an axis 3-3 as will be described hereinafter. The pilot valve body l6 includes a pilot burner 2| having a discharge passage 22 therethrough which communicates with and forms an extension of the pilot passage [1.

A thermostatic control element 23 is mounted on the pilot burner 2| and is adapted to control the positions of the main valve l4 and the pilot valve l9 through an operating mechanism 24 which includes an operating member 28 and an actuating member 21. the operating member being reciprocable along the axis AA and the actuating member being rotatable about an axis C-C. The operating member 26 cooperates with the thermostatic element 23 to control the position of the main valve l4, and cooperates with the actuating member 21 and the thrmostatic element to control the position of the pilot valve l9 as will be described in detail hereinafter.

Considering the construction of the safety device in more detail, the main passage l2 through the main valve body includes an inlet passage 29 and an outlet passage 38 which communicate with each other through an opening 3| in a separating partition 32. The inlet passage 29 extends through a tubular fitting 33 which is formed integrally with the main valve body II and is threaded externally as indicated at 34 for convenience in connecting a main fuel supply line (not shown) to the main valve body. The outlet passage 38 may be threaded as indicated at 35 for convenience in connecting the main valve body II to the main burner of heating apparatus which is not shown in the drawing.

As best shownin Fig. 2, the main valve body H is provided with a bore 31 therein which communicates with the main passage l2 and cooperates with the wall thereof to define the main valve chamber l3, the main valve body also being provided with a counterbore 38 therein which cooperates with the bore 31 to define a shoulder 39 for supporting the main valve l4 in a manner which is about to be described. The main valve l4, which is disposed in the main valve chamber I3, is preferably formed of a flexible and resilient rubber-like material, and includes a central porwith a central guide opening therethrough for 4 the operating member 26 which is slidably journalled therein and extends therethrough into a recess 46 1'1 the main valve l4. The main valve 4 is also provided with a recess 48 therein to define an annular rim 49 which encircles the opening 3| through the partition 32, the annular rim being adapted to seat against the partition to prevent the fiow of fuel through the main passage |2 when the thermostatic element 23 actuates the operating member 26 to displace the main valve into a closed position as will be described in detail hereinafter. The annular flange 42 is willciently flexible to permit displacement of the central portion 4| of the main valve l4 into the closed position and normally tends to hold the central portion in an open position as shown in Fig. 2. However, I prefer to employ a main valve spring 50 to assist the annular flange 42 in urging the main valve l4 toward the open position, the spring being seated in the recess 48 in the central portion 4| of the main valve and being seated against the main valve body I I.

The main valve body II is provided with a boss thereon having a threaded bore 56 therein which receives a complementarily threaded portion 51 of the pilot valve body l8 to connect the main and pilot valve bodies together. The pilot passage |1 includes an inlet passage 58 and an outlet passage 58 which communicate with the pilot valve chamber l8, the outlet passage communicating with the discharge passage 22. The inlet passage 58 includes a bore 60 into which the pilot valve I9 is adapted to extend to control the flow of fuel through the pilot passage H as will be described in more detail hereinafter. In the particular construction illustrated in the drawing, the main valve body II is provided with a boss 62 thereon having a passage 63 therethrough which communicates with the bore 56 in the boss 55 and forms an extension of the pilot inlet passage 58 as best shown in Figs. 2 and 3. The boss 62 is provided with a threaded bore 64 therein for convenience in connecting a pilot fuel supply line (not shown) to the main valve body A pilot valve housing 86 is secured to the pilot valve body It by screws 61 in the particular construction illustrated, and receives the pilot valve l9 therein, the housing extending into a recess 88 which cooperates with the pilot valve chamber l8 to define a shoulder 68. The pilot valve l9 extends through and is slidably journalled in an opening 1| which communicates with the interior of the housing 86, the interior of the housing being defined by a bore 12 and a counterbore 13. The pilot valve I8 is of the needle valve type and includes a stem 14 having a head 15 thereon, the stem terminating in a conical tapered portion 16 which extends into and is adapted to seat in the bore. to prevent the flow of fuel through the pilot passage H. The stem 14 extends through an opening in an actuating element 18 which is adapted for engagement with the actuating member 21 to control the position of the tapered portion 16 relative to the bore 88 as will be described in more detail hereinafter, the actuating element being seated against the head 15 of the pilot valve IS. The stem 14 also extends through a sleeve 18 which is slidably journalled in the opening 1| to permit reciprocation of the pilot valve I9 along the axis 3-3, the sleeve being retained by a nut which is threaded on the stem. The nut 80 also serves as a seat for a pilot valve spring 8| which normally tends to hold the pilot valve IS in a closed position with the tapered portion 16 thereof seated in the bore 60. Another nut 83 is threaded on the stem 14 adjacent the nut 80 to retain a diaphragm 84 therebetween, the edges of the diaphragm being disposed between the pilot valve housing 65 and the shoulder 69. The diaphragm 84 is preferably formed of a suitable flexible and resilient material to permit reciprocation of the pilot valve l9 while providing a means for enclosing and sealing the pilot valve chamber l8.

The pilot valve body It is provided with a theraded bore 85 therein which receives a complementarily threaded portion 86 of a pilot burner tube 81 therein to connect the burner tube to the pilot valve body, the burner tube being a component of the pilot burner 2|. A metering element 88 is disposed in the discharge passage 22 through the pilot burner tube 81, the metering element being provided with an orifice 89 therethrough which meters the fuel for the pilot burner 2|. The pilot burner tube 81 is provided with an air-inlet opening 90 therein which communicates with the discharge passage 22 to introduce air into the pilot burner 2|, the fuel and air being mixed in the pilot passage. The fuel-air mixture is discharged through one or more openings 32 at one end of the discharge passage 22 and may be ignitedto provide a pilot flame as indicated in phantom at 33.

, The pilot burner 2| includes a guide member 36 which is frictionally secured to the :burner tube 31 and which includes arms 36 and 31, the arm 36 having an opening 33 therethrough which receives an end of the burner tube. The arm 36 is provided with a lip 33 thereon which deflects the flame 33 against the arm 31, the arm 31 being provided with a pair of flanges I thereon which protect the thermostatic element 23, and being provided with a guide opening IOI therethrough which receives the operating member 26.

The thermostatic element 23 is secured to the arm 31 of the guide member 35 by a bolt I02, the thermostatic element being disposed between the flanges I00 which prevent direct contact with the pilot flame 93. The thermostatic element 23 is preferably a conventional bi-metal control bar which is formed'of two metal strips having different coefficients of thermal expansion so that the curvature of the bar varies in response to temperature variations as is well known in the art. The thermostatic element 23 is preferably curved when heated by the pilot flame 33, and is preferably substantially straight as indicated in phantom at 23' when the pilot flame is extinguished.

The reciprocable operating member 26 is slidably journalled in the guide openings 45 and IOI and includes a rod I03 which is .operatively engaged by the thermostatic element 23, the rod being provided with a threaded portion I04 having an adjustable extension I threaded thereon which operatively engages the main valve I4. The extension I05 permits adjusting the length of the operating member 26 as required and may be locked in any desired position relative to the rod I03 by a nut I06 which is threaded on the rod. The rod I03 is also provided with a nut I01 thereon which engages the actuating member 21, the nut I01 being locked in any desired position by another nut I08.

'' "The actuating member 2115 pivotally connected "to the pilot valve body I6 bya pivot element IIO which is disposed in a bore-I II through an arm "N2, the arm being formed integrally with the pilot valve body. The actuating member 21 includes a pair of arms H3 and H4 which are operatively engaged by'the nut I01, and includes a pair of arms H5 and H6 which operatively engage the actuating element 18. The arm H6 is provided with an actuating tab II1 thereon for convenience in manually operating the pilot valve I9 as will be described in detail hereinafter.

For convenience in describing the operation of my invention, I shall assume that operation of the safety device is to be initiated. Under normal temperature conditions, the thermostatic element 23 assumes the position indicated in phantom at 23" and applies a force to the operating member 26 in the direction of the arrow II 8 to hold the main valve I4 in the closed position. The closing force applied to the operating member 26 by the thermostatic element 23 overcomes the opening forces applied by the annular flange 42 of the main valve I4 and by the main valve spring 50. The length of the operating member 26 may be varied readily by means of the adjustable extension I05 to insure that the main valve I4 is closed when the thermostatic element 23 is at the prevailing temperature. The pilot valve spring 8| holds the pilot valve I3 in the closed position, the nuts I01 and I00 being adjustable to permit complete closure of the pilot valve. Thus, when the thermostatic element 23 is in the position indicated at 23', the main valve I4 and the pilot valve I3 are closed and no fuel can flow through either the main passage I2 or the pilot passage I1. v 4

In order to put the safety device in operation, the pilot valve I3 may be opened by applying a force to the actuating tab II1 to rotate the actuating member 21 in the direction of the arrow H3. The arms H5 and H6 engage the actuating element 10 to open the pilot valve. Fuel then flows through the pilot passage I1 as indicated by the, arrows I20 and is mixed with air in the discharge passage 22. The fuel-air mixture is discharged through the openings 32 and may be ignited to provide the pilot flame 33. As the thermostatic element 23 is heated by the pilot flame 33,'the element becomes curved and is displaced in the direction of the arrow I 2|. The operating member 26 moves in a direction opposite to that indicated by the arrow III! as the annular flange 42 of the main valve I4 and the main valve spring act to open the main valve, thereby permitting fuel to flow through the main passage I2 as indicated by the arrows I 22. The nut I01 on the operating member 26 engages the arms H3 and I I4 of the actuating member 21 to hold the pilot valve open, the annular flange 42 and. the main valve spring 50 being adapted to overcome the closing force exerted by the pilot valve spring -8I. The position of the nut I01 should be adjusted so that the pilot valve I3 is closed when the thermostatic element 23 is cold and is open when the element is heated by the pilot flame 33.

Once the thermostatic element 23 is heated sufiiciently, the main valve I4 and the pilot valve I3 will remain open and the actuating tab II1 may be released. The main valve spring 50 and the annular flange 42 will hold both the main valve I4 and the pilot valve I3 open as long as the pilot flame 33 continues to heat the thermostatic element- 23.

If the pilot flame 33 should be extinguished for any reason, the thermostatic element 23 will rapidly assume the position indicated at 23' to close the main valve I4, and the pilot valve spring 0| closes the pilot valve I3. Thus, the safety device prevents the escape of fuel if the pilot flame 33 is extinguished, and is particularly adapted for use on such automatic heating equipment as gas water heaters to prevent the escape and dangerous accumulation of gas if the pilot flame is extinguished accidentally by drafts or the like. The operation of the device is positive and reliable at all times and requires little or no attention because of the relatively simple construction thereof.

Although I have described an exemplary embodiment of my invention, I do not intend to be limited to the specific disclosures contained herein since various changes, substitutions, and modiflcations may be incorporated in the exemplary embodiment without departing from the spirit of the invention, and I hereby reserve the right to all such changes, modifications, and substitutions as properly come within the scope of my appended claims.

I claim as my invention:

1. In a device for regulating flow of a combustible fluid, the combination of: a valve body provided with a main valve chamber having a 7 main valve axis and provided with a pilot valve 7 chamber, said valve body having main inlet and outlet passages which communicate with said main valve chamber and having pilot inlet and outlet passages which communicate with said pilot valve chamber; a main valve in' said main valve chamber, said main valve being reciprocable along said main valve axis between open and closed positions to control flow of the fluid from said main inlet passage to said main outlet passage; a pilot valve reciprocable in said pilot valve chamber between open and closed positions to control flow of the fluid from said pilot inlet passage to said pilot outlet passage; a pilot burner carried by said valve body and communicating with said pilot outlet passage, said pilot burner being adapted to produce a pilot flame; a thermostatic element carried by said valve body in the path of said pilot flame; and actuating means controlled by said thermostatic element for moving said main valve and said pilot valve between their respective open and closed positions substantially in unison, said actuating means including a longitudinally reciprocable rod member having a longitudinal axis which substantially coincides with said main valve axis and having ends which respectively engage said thermostatic element and said main valve to control the position of said main valve in said main valve chamber, and said actuating means including a rotatable crank member having a pair of arms one of which engages said rod member at a point intermediate its ends and the other of which engages said pilot valve to control the position of said pilot valve in said pilot valve chamber.

2. In a. device of the character described, the combination of: a valve body provided with main and pilot passages; a main valve associated with said main passage and reciprocable relative to said valve body along a main valve axis between open and closed positions to control flow through said main passage; a pilot valve associated with said pilot passage and reciprocable relative to said valve body along a pilot valve axis between open and closed positions to control flow through said pilot passage, said main. and pilot valve axes extending in mutually perpendicular directions; a pilot burner carried by said valve body and communicating with said pilot passage downstream from said pilot valve, said burner being '3 adapted to produce a pilot flame; a thermostatic element carried by said valve body in the path of said pilot flame; and actuating means controlled by said thermostatic element for moving said main and pilot valves toward their respective open positions, or toward their respective closed positions, said actuating means including a longitudinally reciprocable rod member having a longitudinal axis which substantially coincides with said main valve axis and having ends which respectively engage said thermostatic element and said main valve to control the position of said main valve, and said actuating means including a rotatable crank member having a pair of arms one of which engages said rod member at a point intermediate its ends and the other of which engages said pilot valve to control the position of said pilot valve.

3. A device as set forth in claim 2 wherein said actuating means includes resilient means for biasing said main valve toward its open position and includes resilient means for biasing said pilot valve toward its closed position.

4. A device according to claim 2 including means carried by said rod member for adjusting said point of engagement between said rod member and said one arm 01 said crank member longitudinally of said rod member.

5. A device as defined in claim 2 including means on said crank member for moving said pilot valve toward its open position independently of said actuating means.

- JAMES MAYNARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 909,583 Gold Jan. 12, 1909 1,070,529 Radke Aug. 19, 1913 1,672,223 Larsen June 5, 1928 1,943,075 Harton Jan. 9, 1934 1,960,144 Entuken May 22, 1934 2,042,942 Hirschler June 2, 1936 2,324,100 Maynard July 13, 1943 2,343,904 Hegwein Mar. 14, 1944 2,349,051 Novak May 16, 1944