US2911152A - Thermostatic control device for fluid fuel - Google Patents

Description

Nov. 3, 1959 v. WEBER ETAL 2,911,152

. THERMOSTATIC CONTROL DEVICE FOR FLUID FUEL BURNING APPARATUS Filed Feb. 1, 195e IN VEN TOR5.

United States Patent THERMOSTATIC CONTROL DEVICE FOR FLUID FUEL BURNING APPARATUS y Victor Weber, Greensburg, William J. Sanders, Mount Application February 1, 19.56, Serial No. 562,713

' s Claims. (cl. 236-1) This invention relates to controls for iluid fuel burning apparatus and more particularly to a combination thermostat and safety pilot control for gas appliances.

It is an object of this invention to eiect so-called 100 percent shut-olf of fuel supply in the event of pilot ame extinguishment.

Another object of this invention is to arrange a safety shut-off device to insure safe lighting of the appliance.

Another object of this invention is to control a pilot valve and a safety valve by means of a single thermoelectric device.

Another object of this invention is to permit a resetting operation of the thermoelectric device only in the Offf position of a shut-oir cock.

Another object of thisninvention `is to control a pilot Valve, a safety control Valve, and a temperature responsive valve by a single manually operable-dial.

In one preferred embodiment of the invention, a casing having inlet and outlet openings for fuel is provided with a thermostatic valve and a shut-olf cock to control the flow of fuel therethrough, the operating member of the shut-off cock being associated with the thermostatic valve and rotatable to adjust the temperature at which the same will respond. Valve means are provided in one of the outlets for controlling the ow of fuel to a pilot burner, and a safety control Valve is provided in another outlet to control the oW of fuelto a main burner. A thermoelectric device is associated with the pilot Valve and safety valve and includes an armature operative to maintain said safety and pilot valves in closed positions in labsence of the flame at the pilot burner. The operating member of the shut-off` cock is adapted for reciprocal movement independently of the shut-off cock and is ycooperable with a plunger during reciprocal movement thereof to reset the armature and simultaneously openboth the safety valve and the pilot valve. Means are provided whereby the armature may only be reset in f the OE position of the shut-olf cock.

Other objects and advantages willbecome apparent from the following description taken in connection with the accompanying drawing which is a schematic showing of a control rdevice embodying this invention.

Referring to the drawing, the control device structure is shown as comprising a casing 1t) provided with an inlet 12 and an outlet 14 for supplying fuel to a main burner 16 of a fluid fuel burning appliance by means of a conduit or pipe 18. The casing is provided with another outlet 20 which is adapted to supply fuel by means of a conduit 21 to a pilot burner 22 positioned adjacent the main burner 16 for igniting the same.

The inlet 12 communicates with a tapered valve seat 24 formed in the casing 10 and within which a hollow shut-off'cock 26 is seated and adapted to rotate. Communication lbetween the inlet 12 and hollow interior of the Shut-olf cock 26 is afforded by a port 28 formed in ythe-cock 26. An rarcuate recess 30 is formed in the tapered surface of the shut-off cock 26 and extends from the port 28 sucently to estblih. .registry of the inlet 12 with the port 28 throughout a predetermined arc of rotation of the cock 26, thus establishing an On or open position of the cock 26 in various settings thereof. When the cock 26 is rotated sufficiently to move the recess Stl out of alignment with the inlet 12, the cock 26 is in Off position as shown in the drawing.

The shut-off cock 26 is provided with an axially extending operating stem 32 which projects exteriorly of the casing 1@ through a centrally disposed bore in a cover plate 34 attached to the end of the casing lil. A spring 35 -is mounted in compression between a shoulder of the cock 26 and the cover plate 34 and is operative to bias the cock 26 into engagement with rthe tapered seat 24. The stem 32 carries on its end a slotted collar 36 which carries and is cooperable with a suitably tongued sleeve 38 of a manually operable dial 4t). By means of the slotted collar 36 and tongued sleeve 3S the cock 26 may be rotated between positions by manipulation of the dial 4t), or the dial 46 and sleeve 38 may be moved axially relatively to the cock 26 as is well known in the art.

A sleeve 42 is slidably mounted on the stem 32 and provided with a flange 44 at one end thereof engageable by the end 0f the sleeve 38 and another flange 46 on the other end thereof. A spring 48 is mounted in compression between the flange 46 and a shoulder of the stem 32 and is operative to bias the flange 44 into engagement with the end of the sleeve 38 as shown. If the. dial 40 should be moved axially toward the casing 10, the end of the sleeve 38 will engage the flange 44 to cause movement of the sleeve 42 and compress the spring 48. Upon release of the dial 40 the spring 48 is operative to return the dial 40 to its outward positionzas shown in the drawing.

The hollow interior of the cock 26 communicates with a valve chamber 5@ Within which an annular valve seat 52 is formed on the casing 10 defining a valve port through which fluid may How from the interior of the cock 26 to the outlet 14. A disc-shaped valve member 54 is positionedv in the chamber 56 to be reciprocal into and out of engagement with the -seat 52 and is loosely mounted on a reciprocal and rotatable valve stem 56. VThe valve stem 56 is provided with a generall tapered medial portion on which the Valve member 54 is normally seated', and has one end threaded for reception in an internally threaded tubular adjusting element 58. The other end of the valve stem 56 is provided with a pair of oppositely disposed slots 61) which are adapted to receive a drive pin 6,4 fixed to one end of an operating shaft 66. The

' other end of the operating shaft 66 extends through an axial bore of the cock 26 and is attached to the end 0f the stem 32 by means of a clamping plate 67 and screws 68. A spring 70 is mounted in compression between the shoulder of the casing 10 and the Valve member- 54 and operative to bias the Valve member 54 away from the seat 52. A second stronger spring 71 is mounted in compression between the valve member 54 and the adjusting element 58 to permit override movement of the stem 56 relative to the valve member 54'Wherr the valve member 54 engages the seat 52.

For actuating the valve member 54' between positions, the casing d@ is provided with an opstanding bracket 72 on which a thermostatic mechanism is mounted. The thermostatic mechanism includes an expansible and corrtractible power element 74 carrying a stud 76, which is lxed to the bracket 72. The element 74 is connected to a temperature sensing bulb 78 by means of a capillary tube `8() which extends exteriorly of its casing 10 and may be positioned to sense the temperature of the medium heated by the main burner 16. The power element 74, tube 80, and bulb 78 comprise a closed system filled with a fluid which upon changes in the temperature sensed by the bulb Sti Will serve to expand and contract the power element 74 in a manner well known to those skilled in the art.

For transmitting movement from the power element 74 to the valve member 54, a cup-shaped member 31 has the end thereof fixed to the power element 74 and encioses the end of the adjusting element 5S. A pin 82 is inserted through aligned bores in the walls of the adjusting element 53 and cup-shaped member 81 thereby preventing rotation of the adjusting element 58 and connecting the same with the member S1. A curved bimetal disc `83 is positioned within the member S1 in engagement with the end of the adjusting element for transmitting movement thereto and to compensate for ambient temperature conditions affecting the power element 74.

Rotation of the dial 4l) serves to rotate the cock 26 and operating shaft 66 as a unit. `Rotation of the shaft 66 screws the valve stem 56 into or out of the -adjusting element y58 thereby moving the valve member 54 relative to the seat 52 to vary the temperature at which the same will engage the seat v52 under the inuence of the thermostatic mechanism in a manner well known in the art.

The casing 10 may be provided with a passage 84 which establishes communication between the upstream side of valve member 54 and the chamber 51) thereby permitting a small flow of fuel around the seat 52 when the valve member y54 is closed to establish a minimum lame at the main burner at all times. An adjustment screw 85 is threaded within the casing 15 and is operative upon adjustment thereof to vary the flow of fuel through the passage 84.

From the valve chamber S fuel may flow around the partition '72 and into a second valve chamber Se defined by the bracket 72 and casing 1b. Safety valve means for the main burner are positioned in this chamber and comprise an annular valve seat S3 formed-on the interior of the casing '16B and dening a port through which fuel may ilow to the outlet 14- and main burner 16. A disc-shaped valve member @il is positioned to be reciprocal into and out of engagement with the seat 88 and is carried by a medial portion of an axial movable valve stem 92 which has one end slidably positioned in a guide 94 and the other end thereof extending toward the bracket '72 for connection to an actuating means later to be described. A spring 96 is mounted in compression between the valve member 9i) and tie guide 94 for biasing the valve member @d toward an open position.

For supplying fuel to the pilot burner, the casing '1d is provided with a passage 9S which bypasses the cock 26 and extends from the inlet 12 to a chamber 11i@ in the casing 1@ in which a yfilter cartridge 19,12 of any suitable type may be positioned. A passage 104 connects the filter chamber 11115 with a threaded bore 156 in the wall of the casing 10 in which a valve seat member 153 having an annular seating surface 11@ is threaded. A discshaped valve member 1112 is positioned in the bore 106 and is reciprocal into and out of engagement with the seating surface 111.5 and is biased toward engagement therewith by means of a spring 114 mounted in compression between the valve member `1123 and a bushing 115 threaded in the open end of the bore 1516.

YThe valve seat member 1118 is provided with an axial bore 116 Vin which a plunger 113 of non-circular cross section is slidably positioned. One end of the plunger 11S. engages the valve member 112 and the other end thereof engages a ilexible diaphragm 125 which is clamped into engagement with a shoulder of the bore 1196 by means of the valve seat member 1G33 thereby sealing the bore 156 from the valve chamber 86. T he axial bore 116 communicates with the pilot burner outlet 29 by means of a passage '122 in the valve seat member 168. Upon axialY movement of the plunger 113 toward the bushing y1115, the valve member 112 will be moved out of engagement with the seat to permit ow of fuel through the bore 116, passage 122 to the pilot burner.

A thermoelectric device responsive to a ilame at the pilot burner is provided for actuating the pilot valve member 112 and safety valve member 90 between their operative positions. To this end, a magnet frame 124 is xed to a terminal bushing 126 mounted in the end wall of the casing 10 and connected by a conductor 128 to a thermocouple 130 which is positioned adjacent the pilot burner. A disc-shaped armature 132 is movable between attracted and released positions relative to the magnet frame 124 and is disposed within a housing 134 which substantially encloses the magnet frame `124 and armature 132.

The armature *132 is provided with an axially extending integral stem 2136 which is slidably positioned in a bore in the end of the housing 164 and extends exterior of the housing 134. A coil spring 138 is mounted in compression between the end ofy the housing 134 and the ange 140 formed on the end of the stem 136 and is operative to bias the armature 132 to its released p0- sition as shown on the drawing.

The stem i136 is provided with a reduced diameter portion 142 defining a generally tapered -annular shoulder 144 at the edge thereof. A plunger 146 is slidably mounted in the wall of the housing 134 and has one end engaging the stem 136 and the other end thereof engaging the diaphragm 120 in alignment with the end of the plunger 11S. In the released position of the armature 132 shown, the plunger i146 engages the reduced diameter portion-i142 and is positioned thereby to permit the valve member 1 12 and plunger 118 to assume their biased positions under influence of the spring 1114. However, should the armature 132 be moved .to its attracted position in engagement with the frame` i124, axial movement of the stem 136 will cause the plunger 146 to ride up the tapered shoulder 144 thereby moving the plunger 146 axially toward the diaphragm 123. Such movement of the plunger 146 is sucient to ilex the diaphragm 121B and actuate the plunger 118 toward the bushing 115 against the bias of spring 114 thereby moving the valve Vmember 11112 out of engagement With the seat 11@ to permit flow of fuel to the pilot burner.

The end of the stem 136 is provided with a pintle 148 on which one end of an operating lever 150 is loosely positioned by means of a bore therein. The lever 150 has a medial portion thereof fulcrumed on a screw 152 threaded within the partition 72 and has the other end thereof loosely fitted` on a pintle 154 defined by the end of the safety valve stern 92.

The spring 133 is preferably stronger than combined forces of the springs 96, 114and operative upon deenergization of the magnet 124 to simultaneously move the reduced diameter portion 142 into engagement with the plunger 1146 and rotate the lever 150 counterclockwise onv the fulcrum 152. Thus, the valve members 90 and 112 are both simultaneously moved `to closed positions upon extinguishment of the flame at the pilot burner.

Resetting means are provided for resetting the armature 132 to its attracted position and the valve members 90, 112 to their open positions. To this end', a second lever 156 overlies the end of the lever 150 and has one end thereof loosely connected to the pintle 148 and the other end thereof fulcrumed on a shoulder 158 of the casing 1b. The lever 156 is rotatable on the shoulderV 158 by means of a stem 1611 which has one end thereof engaging the lever 156 adjacent the shoulder 158. The stern 160 extends exterior of the casing 1Q toward the dial 40 and is slidably positioned in a bore in a wall of the casing 10 and in a bore in a lug 162 formed on the exterior surface of the casing 10. The exterior end of the stem 160 underlies the dial 40 and is adapted to be engaged by an abutment 164 provided by the sleeve 38.

The abutment 164 is positioned whereby the same will engage the end of the stem 160 in the Off position of the cock 26 when the Idial 40 is moved axially toward the casing `10. Such axial movement of the dial 40 moves the Stem 160 axially to effect counterclockwise rotation of the lever 156 on the shoulder 158. Rotation of the lever 156 effects axial movement of the armature stem 136 and opening of the valve members 90, 112 as previously described.

Operation To place the device in operation, the dial 40 is rst pushed inwardly in the Off position thereof to cause abutment 164 to engage and move the stem 160 axially toward the lever 156. Such movement of the stem 16) causes counterclockwise rotation of the lever 156 on the shoulder 158 which in turn moves the stem 136 and armature 132 axially until the armature engages the magnet frame 124. This operation also causes axial movement of the plunger 146 by the tapered shoulder 144 and opening of the pilot valve member 112. Also, lever 150 lis rotated clockwise on the fulcrurn 152 to open the safety valve member 90.

Fuel is now supplied to the pilot burner, however, since the gas cock 26 is still in the Oi position fuel cannot flo-w to the main burner. The pilot burner may now be ignited by any suitable means, such as manually, or by means of a flash tube. When the hot junction 139 is heated suiiiciently to energize the magnet 124, the dial 40 may be released whereupon it will assume its outwardly biased position as shown under the bias of the spring 48. The pilot valve 112 and safety valve 90 are now held in their open positions by the magnet y124 and remain in such positions as long as thc pilot burner remains energized.

The dial 40 may now be rotated to any desired temperature setting to supply fuel to the main burner under control of the valve member 54. The valve member 54 is positioned between open and closed positions by the power element 74 in response to variations in the temperature conditions sensed by the bulb 46 in a manner well known in the art.

If at any time the flame ofthe pilot burner should become extinguished, the armature 132 will move under the bias of the spring 138 to the released position shown in the drawing, thereby closing the pilot valve member 112 and the safety valve member 90 as previously described. Thus, the device provides so-called 100 percent shut-off in the event of pilot ame failure. To reset the device after such a failure, the operator must turn the dial 40 to the 01T position wherein abutment 164 overlies the end of the stem 160, thus preventing any flow of gas eX- cept to the pilot burner during the resetting operation. It will be apparent that since the abutment 164 overlies the stem 160 only in the Off position of the Shut-olf cock, the armature cannot he reset in the On positions of the cock, thus insuring safe lighting.

In those instances where it is desirable to have no flow interruption, the abutment 164 may be rattached to the dial 40 whereby the same will engage the stem 160` at the highest dial setting. In this position, the flow of gas is not interrupted and fuel ow to the main burner is available at the time the stem 160 is depressed. With this arrangement, the gas may be flashed instantly to start up the system.

While only one embodiment of the invention has been herein shown and described, it will be apparent to those skilled in the art that the construction and arrangement of parts may be in other ways variously embodied or changed without departing from the scope of the invention as defined in the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In a control device for main and pilot burners, the combination comprising main valve means movable between positions and adapted for controlling a ilow of fuel to the main burner, pilot valve means movable between positions and adapted for controlling a ilow of fuel to the pilot burner, safety valve means movable between positions and adapted for controlling a iiow of fuel to the main burner, thermally responsive operating means associated with said main valve means for actuating the same between said positions in response to a change in a temperature condition, an adjustable element rotatable between positions for setting the temperature at which said operating means will respond, and lever means operatively connecting said safety valve means and said pilot valve means for simultaneously moving said safety valve means and said pilot valve means, said lever means comprising a rst lever ypivoted at one end, a reciprocable member connected to the other end of said first lever, a second lever pivoted intermediate the ends thereof and having one end cooperable with said reciprocable member and having the other end cooperable with said safety valve means for actuation thereof, and a plunger cooperating with said reciprocable member for moving said pilot valve, said adjustable element being reciprocal and in operative engagement with said first lever for moving said safety valve means and said pilot valve means to one of said positions. i

2. A control device as claimed in claim 1 wherein means responsive to a flame at the pilot burner are operatively connected with said lever means for holding said safety and pilot valve means in said one position.

3. In a control device for fluid fuel burning apparatus having main and pilot burners, the combination comprising safety valve means movable between open and closed positions for controlling the flow of fuel to the main burner, means for biasing said safety valve means to said open position, pilot valve means movable between positions for controlling the ilow of fuel to the pilot burner,

electro-magnetic means responsive to a ame at the pilot burner and including armature means movable between attracted and released positions, a plunger extending between said pilot valve and said armature means, means associated with said armature means for causing said plunger to move said pilot valve means between said positions in response to movement of said armature means, and a lever pivoted intermediate the ends thereof having one end operatively connected to said armature means and having the other end connected to said safety valve means for permitting said safety valve means to move to said open position upon movement of said armature means to said attracted position.

4. The device of claim 3 including biasing means operatively connected to move said pilot valve means and said safety valve means to shut off the flow of fuel to the main and pilot burners in response to failure of the flame at the pilot burner.

.5. The device of claim 3 including means operatively connected to move said armature to said attracted position to allow fuel to ow to the main and pilot burners.

References Cited in the file of this patent UNITED STATES PATENTS 2,478,386 Gauger Aug. 9, 1949 2,527,286 Witzel Oct. 24, 1950 2,557,927 Abrams et al. June 26, 1951 2,628,677 Strobel Feb. 17, 1953 2,650,766 Brown et al Sept. l, 1953 2,658,515 Jackson Nov. 10, 1953 2,696,877 Hollman Dec. 14, 1954 2,754,060 Russell July 10, 1956

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