US2201398A - Safety control for gas burning appliances - Google Patents

Description

N O 5 Y A R G H. IJ.

SAFETY CONTROL FOR GAS BURNING APPLIANCES s sheets-sheet '1 Filed June 14, 1957 EN QN 21, 1940. J. H. GRAYsoN 2,201,395

SAFETY CONTROL FOR GAS BURNING APPLIANCES Filed June 14. 1937 3 Sheets-Sheet 2 um A wv l/ Non.

l i fm/mrz May 2l, 1940. J. H. GRAYsoN l SAFTY CONTROL FOR 'GAS BURNING APPLIANCES Filed June 14, 193'? 3 sheetysheet 5 Patented May 21, 1940 S'llY CONTROL FOR GAS BURNING APPLIANCES lohn lill. Grayson, Lynwood, Calin, assig-nor to Grayson Heat Control, Ltd., Lynwood, Calif., a corporation of California Application June 14, 1937, Serial No. 148,036

6 Claims.

This invention pertains to gas burning appliances and while the principles thereof may be utilized in controlling the fuel supply in many different types of gas burning devices, the invention is here shown-and described for illustrative purposes merely, as being embodied in an apparatus for controlling the fuel supply to a gas burning domestic water heater.

One of the primary purposes of my invention w is to provide a fuel control which in normal operation will thermostatically regulate the fuel supply to the main or heating burner so as to maintain a quantity of water heated to a predetermined temperature and which, upon extinguishment of the pilot burner by which the main burner is lighted, will automatically and completely shut off the fuel supply not only to the main burner but also to the pilot burner so that no fuel can escape through either burner until 2U, the device has been manually reset and the pilot burner has been relighted.

Another object of the invention is to provide for a control device of this character a starting mechanism which, when set to starting position,

will connect the pilot burner with the fuel supply ahead of the safety valve so that said burner may be relighted and when subsequently set to operative position will open the safety valve to permit a fuel flow to the main burner and will simultaneously switch the fuel supply to the pilot burner from a point in front of the safety valve to a point rearwardly of this valve so that when the safety valve subsequently closes lt will shut on the fuel supply not only to the main burner but also to the pilot burner.

Another feature of my invention resides in the employment of a thermomagnetic device for normally maintaining the safety valve in open position, which device embodies a thermocouple positioned to be energized by the heat from the pilot burner so that when so energized it will maintain the safety valve in open position but when deenergized by extinguishment of the pilot burner will permit the safety valve to be promptly closed.

Another object of the invention is to provide a compact and reliable unit embodying a thermostatic control valve, a thermomagnetlcally controlled safety valve, and a manually adjustable 5G shut-off valve by which the fuel supply to both the safety valve and the thermostatic valve may be shut 0E when desired.

Another feature of the invention resides in the manually operable starting device by Which the fuel supply to the pilot burner is initially estab- (ci. 15s-117.1)

lished independently of the safety valve and is subsequently established at a point rearwardly of the safety valve so that closure of this valve will shut off the fuel supply to the pilot burner, and furthermore the same manipulation of the 5 starting device which switches the source of fuel supply to the pilot burner, automatically opens the safety valve so that the fuel supply to the pilot burner is not interrupted.

Additional advantageous features of the invenl0 tion will be found in the construction, arrangement and novel combination of the various elements, all of which will be apparent as the same become better understood by reference to the following description when considered in connecl5 tion with the accompanying drawings.

Referring to the drawings:

Fig. 1 is a longitudinal sectional view through a control device embodying the principles of my invention; 2@

Fig. 2 is a fragmentary elevation showing the upper portion of the device;

Fig 3 is a partial elevation and partial section taken on the line 3-3 of Fig. 1;

Fig. 4 is a sectional view on the line l-l of 25 Fig. 3;

Fig. 5 is a fragmentary sectional view through the starting valve, the parts being shown in starting position;

Fig. 6 is a similar View showing the position 30 of the parts during normal operation;

Fig'. 7 is a fragmentary view, partially in elevation and partially in section, taken on the line 'l--l of Fig. 1;

Fig. 8 is a fragmentary view similar to Fig. 2 35 showing the parts on an enlarged scale;

Fig. 9 is a sectional view on the line 9 9 of Fig. 2; and

Fig. 10 is a sectional view on the line I ll-l il of Fig. 9.

Referring now to the drawings more in detail, it will be observed that the device comprises essentially an elongated casing il provided near one end with a laterally extending intake nipple l2 adapted to be connected with a gas main or 45 other source of fuel supply and an outlet nipple i3 designed to be connected by suitable piping with the main or heating burner of the appliance, a fragment of such burner being shown at the right in Fig. 1 and designated by reference 50 character ld.

The upper portion of the casing is shaped to provide a tapered valve seat I5 adapted to accommodate the tapered shut-off cock i6 of hollow construction having one side cut away as 55 g5 by the pilot burner 36 to thereby establish an. Assuming that the pilot burner is extinguished, 715:4

indicated at i1 (Fig. 3) to afford communication between the .nipple i 2 and the bore oi the cock through which the fuel is delivered into the casing of the device when the cock is in the open position shown in Fig. 4. The size of the opening and consequently the fuel flow may be regul lated byan adjustable plug I9 in the bore of the cock. The cock may be manipulated by the usual disk or handwheel 2l. A screen 22 disposed across the bore of the cock protects the automatic control valves against entrance of rust akes or other solidparticles from the fuel supply line which might when lodged upon the seats interfere with the closing of these valves.

An arcuate passage 23 `around the cock plug i6 communicates through a horizontal passage 24 andan inclined vertical passage"25"with"a chamber 26 formed in the body of the casing andA tapered throughout a portion of its length to receive a tapered valve plug 21 having a cored passage 28 extending from its inner end and a pair of ports 29 and 3i communicating with saidl passage. A. passage 32 leads from chamber 26 to a passage 33 (Fig. 4) in a lateral extension of the casing body, which Ylatter passage communicates through a suitable coupling connection 34 with a tube 35 connected as shown in Fig. 1 with a pilot burner 36. An adjustable valve 31 threaded into the outer end of passage 33 may be regulated to control the flow of fuel to the pilot burner from the passage 32, this valve being normally protected against tampering by a protective cap 38. When the parts are in the position shown in Fig. 5, a continuous conduit for the ow of fuel from the supplynipple I2 to the pilot burner 36 is established through conduit 23 and 25, port 29, bore 28, chamber 26, conduits 32 and 33, and tube 35.

The casing ii beneath the cock I6 is provided with a valve seat 39 against which a valve 3i is urged by a spring 42 and access to which may be had by removal of the cap 43. 'I'he valve stem comprises two relatively adjustable parts 44 and 95, the latter of which engages a flexible sealing disk 46 clamped around its peripheral margin between a shoulder 41 formed in the casing and the annular end portion 48 of a cage 49 formed integrally with the valve seat 39 and provided with radial ports 5l through which gas passing the valve may flow to exit through the passage 52.

The opposite face of the disk 46 is engaged by the curved end of a lever 53, best illustrated in Fig. l0, fulcrumed upon a pin 54 and provided at its outer end with a laterally offset cam 55, the purpose of which will be later explained. A stem 56 abutting the outer face of lever 53 and extending through the base of a horseshoe magnet 51 carries at its outer end an armature bar 59 which is urged toward the poles of the magnet by a light spring 59 interposed between this bar and the surrounding shell 6l. Spring 42 being much stronger than spring 59 tends to hold the parts'in the position shown in Fig. 1.'

The horseshoe magnet 51, which is not of the permanent magnetization type, is wrapped by the coils 62 of a wire 63, one end of which is anchored at 6Bv to a conducting member 65 upon which the base oi.' the magnet is mounted and the other end is connected with one element 66 of a thermocouple. the other element 61 of which is connected through a tube 68 with the conducting member 65. The thermocouple is supported by a bracket 69 in position to be heated electric current through the coils 62 of sumcient strength te energize the magnet 51 and heid the armature 58 in contact'therewith against the force of spring 42 when once the armature has been brought into contact with the magnet in a manner which. will now be explained. Upon the outer end oi' the pilot burner light control valve plug 21 there is iixedly mounted a hand operable lever 1I provided, as shown in Figs. 2 and 8, with a`slaterally projecting cam member 12 positioned to cooperate with the cam 55 and rock the lever 53on its pivot as the lever 1l is moved from the position shown in Fig. 2 to that shown in Fig. 8. This actuation of the lever will cause the inner end thereofl to' ii'ex the diaphragm 46 and push the .valve 4I away from its seat against the action of spring 42. Simultaneously armature bar 58 will be urged by spring 59 against the poles of the magnet 51, and if the magnet be energized the armature will be mag'- netically held in contact therewith to retain valve 4| in open position. Flow of fuel to the main burner will accordingly be permitted subject, however. to control by the thermostatic valve mounted in the casing Il beneath the thermomagnetically controlled valve.

The thermostatic valve designated by reference character 13 is urged against its seat 14 by a spring 15. This valve is controlled by a thermostat comprising a tube 16 having a high coeiiicient of expanslon'mounted at its inner end in a nipple extension 11 of the main casing and a rod 18 having a low coefficient of expansion threadedly connected at 19 to a plug 8l anchored in the outer end of tube 16 and adapted upon contraction of tube 16 to exert a thrust through a cap82 against a thrust member 83 within the casing. This .thrust member is provided with an annular knife-edge shoulder 84 adapted to cooperate with a companion annular shoulder 85 to flex a thin metal clicker disk 86 from the. position shown in Fig. 1 to a reverse convex position to thereby force the valve 13 oif from its seat. Adjustment of the thermostat may be .effected through a lever 81 secured by a set screw 88 or otherwise to the outer end of the rod 18 in the usual manner.

During normal operation ot Vthe control, the safety valve 4 I is, of course. open as previously explained, and the flow of fuel to the main heatingA burner is controlled by the thermostatic valve 19 which is .opened by the clicker disk 96 upon contraction of the thermostat tube 16 when the temperature of the surrounding medium falls below a predetermined point and is again closed by the spring 15 when, as the result of a higher temperature of the medium being controlled, the tube 16 expands suillciently to permit the clicker disk 86 to reassume the position shown in Fig. l.

During this operation the lever 1i is set to the position indicated on in Fig. 2 and illustrated'in dotted lines in Fig. 6. In this position of the lever and the valve 21, the fuel to the eof pilot burner 36 is supplied not through the pase sages 24 and 25 as it was when lever 1I was moved to start position but is supplied through a passage 89 (Figs. 3 and 6) which communicates at its lower end with the chamber between the safety valve M and the diaphragm 46. In other words the fuel is supplied to the pilot burner rearwardly of the safety valve 4I so that when this valve is closed the supply of fuel to the pilot burner is shut olf, thereby precluding fuel loss from the pilot burner.

the parts are in the position shown in Fig. 1 and that it is desired to start operation, the modus operandi is as follows: Lever 1| is swung to start position shown in Figs. 5 and 8, its movement being limited by engagement of a rearwardly projecting nnger 9| with an abutment 92 (Fig. 8) carried by a spring plate 93 which overlapsthe head of the plug valve 21 to hold the plug against its seat, this plate being secured in position by a screw 94. The other prong of the plate is provided with an abutment S5 in the path of the finger 9| to limit swinging movement of lever ll in the opposite direction. Movement of lever 'Il to start position brings port 29 and valve plug 2l into alignment with passage 25, thereby per-` mitting a flow of fuel from the intake nipple I2 of the device to the pilot burner 35 through the route previously described. 'I'he fuel issuing from the pilot burner is now lighted by a match or otherwise and the heat therefrom directed against the thermocouple $6, 61 generates an electric current which passes through the energizing coils 62.

After the lapse of a time interval sufficient to energize the magnet 5l, the lever 'H is swung in a counterclockwise direction, viewing Figs. 2 and 8, to the on position illustrated in Fig. 6. This movement shuts oi the passage 25 and simultaneously establishes communication between the safety valve chamber at the delivery side of the valve and the pilot burner. This movement of thevstarting lever il wipes the cam member l2 across the lever cam 55, thereby swinging the lever 53 in a clockwise direction, viewing Fig. 10, and to the left, viewing Fig. l, to open safety valve 4i and permit the armature bar 58 to engage or approach the poles of the electromagnet 5l under the influence of spring 59. While the electromagnet is not strong enough to pull the bar 58 against the force of spring 42, it is sufficiently strong to hold the bar against the end of its poles against the force of this spring when the magnetic circuit is closed through the bar. The electromagnet, therefore, will hold the safety valve in open position so long as the electromagnet remains energized by the thermocouple under the influence of the flame from the pilot burner. Fuel will, therefore, flow to the main burner under the control of the thermostatic valve 13 so long as the pilot burner remains lighted. Upon extinguishment of the pilot burner, however, the resultant decrease in energization of the electromagnet will promptly permit the safety valve M to be closed by the spring 42 even before the electromagnet is completely deenergized. 'I'his closing of the valve shuts off the fuel supply both to the main burner and to the pilot burner so that no fuel loss will occur while the apparatus remains inoperative. The fuel supply will thus remain shut oi irrespective of the position of the thermostatic valve 'I3 until the starting lever 1| is again moved to start position and the pilot burner has been relighted, whereupon after a suitable interval the starting lever may be moved to on position and normal operation will ensue.

While I hav?n shown and described a preferred embodiment of my invention, obviously the structural elements" disclosed for illustrative purposes merely are capable of considerable modification and variation without departure from the essence of the invention as defined in the folllowing claims.

I claim:

1. In a fuel control device, the combination of a casing, a safety fuel valve therein, a pilot burner,

a pilot burner control valve. conduits extending from said control valve into said casing both forwardly and rearwardly of said safety valve, manually operable means for positioning said control valve to supply fuel to the pilot burner from forwardly of the safety valve for starting purposes and for subsequently positioning said valve to supply fuel to the pilot burner from a point rearwardly of the safety valve, and means operable by said manual means for opening said safety valve when the control valve is moved from said irst position to said second position.

2. In a fuel control device, the combination of a safety valve, a pilot burner, a pilot burner control valve connected to supply fuel to the pilot burner from a point forwardly of said safety valve or from a point rearwardly thereof, manually operable means for positioning said control valve, and means positioned to be operated by said manually operable means for opening said safety valve when said control valve is moved to a position to supply fuel to the pilot burner from a point rearwardly of the safety valve.

3. In a fuel control device, the combination of a casing, a safety valve, and a pilot control valve mounted in said casing, a pilot burner connected with said control valve, a conduit in a wall of the casing connecting said control valve with the interior of the casing forwardly of the safety valve for supplying fuel to the pilot burner for starting purposes, a conduit in the casing establishing communication between said pilot control valve and the interior of the casing rearwardly of the safety valve for supplying fuel to the pilot burner for normal running purposes, a common manually operable means for opening the safety valve and simultaneously moving the pilot valve from starting to running position, and means rendered operative by the flame of the pilot burner for holding said safety valve in open position.

4. In a fuel control device, the combination of a casing forming a conduit for supplying fuel to a heating burner, a safety valve mounted in said casing for controlling the flow of fuel therethrough, a pilot burner, a pilot control valve mounted in the casing, branch conduits formed in the casing walls establishing communication between said pilot control valve and the conduit through the casing at points'forwardly and rearwardly, respectively, of said safety valve, the pilot 4 valve being adapted to be positioned to supply fuel to the pilot burner from a point forwardly of the safety valve for starting purposes and from a point rearwardly of the safety valve for running purposes, a control valve operating member, means including a cam and a lever operable by said member upon movement of the pilot valve from starting to running position for opening said safety valve, and means controlled by the flame of the pilot burner for holding said safety valve in open position.

5. In a fuel control device, the combination of a safety valve, a pilot burner, a control valve connected to supply fuel to the pilot burner from one source for starting purposes and from another source for running purposes, a manually operable device whereby said control valve may be positioned. means operable by said device to open said safety valve upon movement of said device from starting to running position, and means rendered operative by a flame from said `pilot burner for preventing the closing of said open said safety valve upon movement of said device from starting to running position, and means rendered operable by a ame from said pilot burner for preventing the closing of said safety valve so long as the pilot burner remains 5 lighted.

JOHN H. GRAYSON.

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