US2273127A

US2273127A - Heating control system

Info

Publication number: US2273127A
Authority: US
Inventors: William J Mcgoldrick; Frederick S Denison
Original assignee: Honeywell Inc
Current assignee: Honeywell Inc
Priority date: 1938-07-15
Filing date: 1938-07-15
Publication date: 1942-02-17
Anticipated expiration: 1959-02-17

Description

Feb. 17, 1942. w. J. MGOLDRICK EIAL HEATING CONTROL SYSTEM Filed July 15, 19,38 2 Sheets-Sheet l lnomtora William JoMEGWBdWiQk Frederick Samson attorney Patented Feb. 17, 1942 FICE HEATING CONTROL SYSTEM William J. McGoldrick and Frederick S. Denison,

Minneapolis, Minn., assignors to Minneapolis- Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application July 15, 1938, Serial No. 219,368

14 Claims.

Qur invention pertains to the art of heating control devices and is particularly concerned with a temperature controlled gas valve or the like having novel safety features and characteristics.

Referring generally to our invention, we employ a temperature responsive safety device for closing a gas valve or the like which closes the valve whenever an unsafe condition is indicated by the device. In the event of shut-down brought about by an unsafe condition, the device must be manually reset to its original position. Our device is of such a nature that while itis being reset, that is manipulated to its original position, the parts coact in a manner to maintain the valve g closed. Thus the valve cannot 'under any circumstances be opened until the device automatically remains in its original or reset position indicating the disappearance of tion.

The invention adapts itself preferably to a gas fired heating j system wherein the safety shutdown device is normally energized by a thermocouple heated by a gas pilot flame. Upon extinguishment of the flame, which, of course, is a dangerous condition, the device is deenergized and closes the valve. The device may then be manually reset to its energized position, the resetting mechanism being of such a nature as to keep the valve closed during manipulation thereof and the device'will, of course, not remain in its energized position until the pilot flame is again burning. therefore avoided in that the gas valve cannot the unsafe condibe even momentarily opened to admit passage of. shotsof combustible-fluid therethrough while an A Elimination of a serious hazard is operative manipulates the safety shut-down de-' vice in an efiort to reset the same after a shutdown due to pilot flame failure. Thus after a safety shut-down any opening of the valve is dependent upon successful remedying of the unsafe condition. which brought about the shutdown. In other words, in the instance of a pilot flame responsive \device as we have referred to,

for example, if the pilot flame goes out shortly after an operative has relit it, our invention precludes the danger of his momentarily opening the valveand admitting a shot of gas to the burner whilehe attempts to manually reset the safety device. The gravedanger otherwise present is 'obvious; the operativeupon finding he cannot manually reset the device, again lights the pilot burner, and without our invention, having admitted a shot of gas to the main burner, a serious explosion results.

Theprincipal object of our invention is to provide a device for eliminating the danger, the

' nature of which we have outlined above.

Another object of our invention is the provision of a thermo-couple energized device for closing a fluid fuel gas control valve or the like upon the occurrence of an unsafe condition such as extinguishment of a pilot flame.

Another object is the provision of an automatic valve closing device having manual reset apparatus which acts to keep the valve closed when the device is being reset.

Another object is the provision in a pilot controlled gas valve of an automatic safety shutdown device which closes the main valve and at the same time closes an auxiliary valve preventing any further flow of gas to the combustion region.

Another object is the provision of an automatic temperature responsive valve closing device having manual reset apparatus which acts to keep the valve closed when the device is being.

reset and additional temperature responsive mechanism for automatically operating the manual reset apparatus in a manner to close the valve at unsafe temperatures.

Other useful objects and advantages of our device will become apparent as the specification proceeds, the invention residing in the structure, combination, and arrangement of parts. and toward which wev have directed the appended claims.

Figure 1 of the drawings is a cross-sectional view of a preferred form of the valve of our invention taken along the line I--I of Figure 2, and showing diagrammatically the manner of incorporation of the valve in a gas fired heating system including the controls therefor.

Figure 2 is a plan view of the valve of Figure 1.

Figure 3 is a view partly broken away to show in cross section a modified form of our improved valve.

Referring to Figure 1 of the drawings, numeral l indicates generally the body of our valve. -In our particular arrangement, we have incorporated a pressure regulating valve within the same structure as the control valve, the pressure regulating valve being shown at the lower part of the valve.

structure of Figure 1. The valve apparatus has an inlet at 2 which may be connected by suitable means to a gas supplymain, it being understood that we preferably employ our invention in a gas fired heating system. The gas which may be ,admitted through inlet 2 passes through the pressure regulator and then through the control valve, as we will later describe, and passes out through an outlet indicated at 3. The outlet 3 may be connected by a conduit 4 with a gas burner 5 of conventional type disposed within a unit air heater indicated generally at 6. While other types of heating apparatus may be employed with our invention, we have chosen to disclose it in connection with the heater 6 which may be one of conventional type comprising a casing, as shown, having disposed therewithin a plurality of cells 1 through which air may be forced in heat exchange relation with the gases of combustion within the heater. The cells i may be connected with a suitable inlet header, or the like, 8 and a device such as a fan or otherwise may be employed to force the air of the room or other space being heated through the heater 3. The heater 6 has a stack or flue 9 through which the burnt gases of combustion may be carried away. Numeral Hi indicates a tube which may communicate with the inlet. side of the valve apparatus and which conveys gas to a constantly burning pilot burner i i, as conventionally used in this type of apparatus.

Referring again to the valve structure, it will be seen that the internal configuration is such as to form an inlet chamber i2 from which gas may pass through the pressure regulating valve and thence to the control valve. The seat of the pressure regulating valve is formed by a screw plug i3 which engages in screw-threaded relation with a corresponding opening in the lower wall portion of the inlet chamber i2. The lower part of the valve body I has an annularly shaped boss I4, the surface of which corresponds in shape to the surface of a flange l5 formed integrally with a member I6 forming a part of the pressure regulating valve. The flange i5 is secured to the boss M by screws, or the like, which do not appear on Figure 1, there being interposed between the flange I5 and boss I4 the peripheral portions of a circular diaphragm H which may be made of any suitable material, such as leather. Numeral I8 indicates the valve member of the pressure regulator, this valve member being secured by suitable means to a valve stem l9 having a screw-threaded portion 20 extending through the diaphragm i1. Disposed above the diaphragm I1 and adjacent thereto 'is a metal disc backing memberZI and on the lower side of the diaphragm is a spring retaining nut 22 which serves to retain the diaphragm, the valve stem l9, and the disc backing member 2| in their proper respective relation. The member I6 is substantially cylindrical in shape, as shown, and engaging. therewith in screw-threaded relation is an adjusting screw 23 which carries a second spring retaining element 24 at its end within the member l6. Disposed between the spring retaining nut 22 and the spring retaining element 24 is a coiled compression spring 25 which engages with a suitable shoulder on each of the spring retaining members. Engaged on the adjusting screw 23 external of the member H; are look

nuts

26 and 21 for rigidly securing the adjustment screw 23 in any desired position. Obviously, the tension of the coil spring 25 may be adjusted by adjusting The portion of the adjusting screw 23 external of the member I6 is protected by a cylindrically shaped guard 28 which frictionally engages the member l6.

. The pressure regulating valve which has just been described operates in the conventional manner of such valves to maintain a constant pressure on its outlet side regardless of fluctuathe tension screw 23.

tions in pressure in the gas main which communicates with the inlet conduit and the details of this valve form no part of our invention.

Gas from the outlet side of the pressure regulating valve enters the chamber above the diaphragm H and then passes through a channel I ,of Figure 2. The top or cover for the control valve comprises a housing 35 having a flange 36 similar to the corresponding portion forming the upper part of the body and having a fiat platelike portion 3'5, the shape of which conforms to the portion 34 of the valve body. The flange 36 and the plate-like portion 31 of cover 35 are secured to the body of the valve, the portions which are secured together having interposed therebetween the peripheral-portions as shown of a diaphragm 38 which may be made of material .similar to that of the diaphragm i1. Screws 43 (Figure 2) may be employed to secure the parts together in the same manner as previously described in connection with the pressure regulating valve. Disposed adjacent the central portion of the diaphragm 38 is a valve disc 39 made of suitable material which may be the same as the material of diaphragm 38 and on the opposite side of the diaphragm is a metal disc backing member 40. A metal disc backing member 4| may also be employed adjacent the valve disc 39, the discs and the diaphragm being secured together by a bolt 42; the bolt having washers disposed between its head and the metal disc backing member 43, as shown, if desired.

Within the housing 35 is disposed an electrical coil winding 45 having suitable insulation thereon, the ends of which extend through the fitting 46 in a side Wall of the housing 35. External of the housing, the terminals of the winding 45 connect with a thermo-couple 41 disposed in the flame of the pilot burner H by,

electrical conductors

48 and 49. The coil winding 45 cooperates with an electromagnet 50 disposed there-within and for purposes which will presently become more apparent the coil winding 45 is of a type having very low resistance to flow of current therethrough and electromagnet 50 is made of iron having high permeability. The electromagnet is connected to a plunger 5|, the lower end of which is pivoted to one end of a link 52 by means of a pin 53. The link 52 has a lug I on its lower side as shown. The plunger 5| extends through a spring retaining element 54 suitably secured within the housing 35, as shown. Secured to the lower end portion of the plunger 5| is a spring supporting disc 55 and between the disc 55 and the element 54 is disposed a coil spring 56 which encircles the plunger 5|, as shown. The coil spring 56 continuously biases the plunger 5| downwardly. The opposite end of the link 52 is pivoted to the lower end of a second plunger 51 I 2,278,127 spring retaining nut 6| and between this nut and the packing nut 56 is a coil spring 62 which encircles the plunger 51 and engages with suitable shoulders on the nuts 6| and 56. The coil spring 62 biases the plunger 51 in an upward direction so that the right end of the'link 52 is normally held in the position shown in the drawmgs.

The plunger 51 may be actuated by a mechanism -which we have indicated generally at 65 on Figure 1. This mechanism is journalled on a spindle or shaft 66 this shaft or spindle forming an arbor mounted in a portion of the housing 35 as may be seen by referring to Figure 2. Inasmuch as the mechanism 65- is external of the housing 35 and as Figure 1 is a cross-sectional view, we have shown the mechanism 65 above the cross-sectional view of the valve structure itself in Figure 1. However, its exact position and that of the shaft 66 may be readily determined from Figure 2 and the operative relationship of the mechanism 65 with respect to the plunger 51 will be understood as the specification proceeds further. The mechanism 65 comprises a lever 61 having a U-shapedportion 66 engaged on the shaft 66. Encircling the shaft 66 is a coil spring 66 having one end I6 extending through the shaft 66 and having the other end II bent at right angles and engaging with an external surface of the housing 35, as may be seen on both Figures 1 and 2. The coil spring 66 biases the lever 61 in a clockwise direction for a purpose which will become apparent later. 66 is a lever I4 having an angular portion I5 which is horizontally disposed and which may engage with the nut 6| as may be readily seen by referring to Figures 1 and 2. By means of a manual operating stem I6 which may have a suitable handle (not shown) the lever I6 may be rotated in a clockwise direction about the shaft 66 so that the angular portion I5 engages nut 6| so as to force the plunger 51 downwardly for a purpose which will be hereinafter described.

The U-shaped portion 68 of lever 61 has an integral angular configurated lug element 'I'I which is clearly shown on Figure 2 and which may engage with the horizontal angular portion I5 of the lever I4. Thus when the lever 61 is moved in a clockwise direction, the lug 'I'I may coact with the lever I4 and the, nut 6| so as to force the plunger 51 downwardly in the same manner as described above. The lower end of the lever 61 is notched, as shown as I6, and engaged upon this end of the lever is a perforated member 16. The member I6 is attached to one end of a flexible transmission shaft 66 which extends through a curved tube 83 to the interior of the unit heater 6. The end of the flexible shaft within the unit heater 6 is attached to one end of a fusible link 6| which is responsive to the temperature within the heater adjacent the cells '1. Theother end of the fusible link 8| may be sup- Also pivoted on the shaft statically controlled pilot valve unit indicated generally at 61. The three-way pilot valve comprises a body 66, the lower part of which is flanged as can be seen on Figure 2, the flanged portion being secured to the previously described portion 31 by screws 66 orthe like as visible on Figure 2. Interposed between the flange at the lower part of the body 66 and the portion 31 is a gasket 66 for the purpose of providing a gas tight seal between the parts. The interior of the body 66 communicates by a port 66 with the inlet chamber I2 of the main valve structure, this port 66 extending through the gasket 66 through the portion 31, the diaphragm 36, and the body I, as shown on Figure 1 of the drawings. The three-way pilot valve comprises a double valve member 61 cooperating with an upper seat formed in a plug member 62 which engages in screw-threaded relation with the interiorportion of the valve body and which may also cooperate with a lower seat 63 formed within thebody 66. The valve 6I is disposed within a chamber 66 which communicates by means of a port 65 'with the interior of housing 35 above the diaphragm 36, the.

port 65 extendingthrough the body 66 through the gasket 66 and through the portion 31, as shown best. in Figure l. the valve member 6| by means of a screw plug 66 in the side wall of the body 66, as shown. The chamber 66 communicates through the' lower pilot valve with an outlet chamber 61-within the body 66 and the chamber 61 is connected through a suitable fitting to a tube 66 which communi- I cates with an auxiliary pilot bumer 66. The stem I66 of the pilot valve 6| extends through the plug 62 and is connected through a strain release mechanism to a device indicated at I6I forming a solenoid armature. The strain release mechanism comprises a coil spring I62 encircling the stem I66 and disposed so that one end engages the interior of the solenoid armature MI and the other end-abuts a nut I 63 engaged on the end of stem I66. Obviously, the strain release mechanism provides a certain amount of resiliency in the connection between the solenoid and the valve member 6| for the conventional purpose for which strain release mechanisms a e intended. In screw-threaded relation with the upper part of the body 86 is a ring nut I64 having a suitable annular shoulder which engages a cover member I65 and maintains it securely in body 68. The cover member I65 has a flanged portion as shown secured to a guide I66 for the ported in any suitable manner as, for example.

by a bracket or the like indicated at 62. The end of the tube 83 terminates in a suitable fitting adjacent to and exterior of the unit heater 6. The end of the tube 63 which is adjacent to the control valve may be supported by means of a su table bracket 64 and a second adjustable bracket 65, as more clearly shown in Figure 2. The bracket is diagrammatically indicated on Figure 1 as part of the mechanism generally indicated at 65.

The valve 32 is preferably controlled by a three-way pilot valve forming part of a thermosolenoid armature IIII and within which the solenoid armature is adapted to be reciprocated. The solenoid armature and the usual electric coil winding associatedxtherewith' are contained within a housing I61 which may be removed at will by loosening a ,thumb screw I66. The coil winding cooperatingwith the solenoid may be of conventional type and arrangement and its terminals extend through a suitable adaptor I66 in g the side wall of the housing I61 and are con- 4 erally indicated at H2.

nected with electrical conductors H6 and III. The unit 61 may be controlled preferably by a room thermostat, for example. which may be of the conventional bimetallic element type as gen- The thermostat I I2 includes a movable switch blade II3 cooperating with a flx'ed electrical contact 4, the contact I connecting with the wire H6 and the ther- -mostat itself being connected to a wire H5. The

wires II I and H5 may connect to a source of external electrical supply at suitable voltage which Access may be had to to produce certain operation which. will be more 7 precisely set forth hereinafter.

Referring now to the operation of the modiflcation of Figure 1, with the parts in the position shown, the thermostat H2 is satisfied and the valve member is in engagement with its lower seat. With the pilot valve in this position, gas' passes from the inlet chamber l2 through the port 90 to the interior of the pilot valve body 88, then through the plug 92 into the valve chamber 94 and then through the port 95 into the interior of the housing 35 above the diaphragm 38. Pressure above the diaphragm keeps the valve 32 closed as long as the thermo-' stat H2 does not call for heat.

The pilot burner ll burns continuously and consequently energizes the thermo-couple 41 so as to cause an energizing current to flow in the coil 45 which maintains the electromagnet 50 in its uppermost position with the plunger and link 52 in the position shown in Figure 1. The plunger 51- and the mechanism 55 are at this time also in the position shown in Figure 1, the lever 51 being maintained in the position shown by reason of the flexible shaft 80 preventing the coil spring 59 from rotating the lever 61 in a clockwise direction. a Y

Now should the thermostat H2 close indicating the need for heat in the spaces or regions being served by the unit heater 5, an electrical circuit will be completed through the electromagnet pilot valve unit 51, through the wires llli, Ill, and H5. Upon energization of the latter unit, the solenoid armature llll will be reciprocated verticallyand the pilot valve member 9| will be caused to seat upon its upper seat closing the passageway through the plug 92. Communication of gas from port 90 through plug 92 will now be cut off and gas pressure within housing 35 and above diaphragm 38 will be released through port 95 to valve chamber 94 through the lower pilot valve into outlet chamber 91 and thence through the tube 55 to the auxiliary pilot burner 99. Upon release of pressure from above the diaphragm 35, the valve 32 will open with a snap action in the conventional manner of diaphragm type valves and gas will be permitted to flow through the pressure regulator and through the valve 32 and to the burner 5 for heating at the unit heater 5. Heat will be supplied as long as the thermostat I I2 is closed and any suitable means may, if desired, be employed to control a fan or the like for forcing the air of the rooms or spaces being heated through the conduit 8 and cells I of the unit heater 5. With this type of unit heater, there is a very rapid exchange of heat between For this reason, we employ the fusible link 5| mounted adjacent the cells I and in the event of the above described failure of air circulation the temperature adjacent the fusible link 2| rises to a relatively high value. This link will fuse thereby releasing the flexible shaft 80 and permitting the coil spring 58 toduickly rotate the lever 51 and its integral lug 11 in a clockwise direction. As described in the structural description, the lug-11 will engage the horizontal portion I5 of the'leveri'l4 which in turn engages the nut 5| at the upper end of plunger 51 there- .by forcing plunger 51 downwardly so that the center portion ll of link 52 engages with the bolt 42 in a manner to instantly close the valve 32. Thus it will be seen that at a predetermined relatively high and unsafe value of temperature within the unit heater 5, the fusible link 8| fuses and causes immediate shut-down of the valve mechanism cutting off the supply of fuel to the burner. The "fusible link arrangement provides a safety mechanism which assures elimination of the danger of the temperature within the unit heater becoming high enough to cause damage thereto. r

If at any time, the flame of the pilot burner II which normally should burn constantly be- "comes extinguished thereby creating an unsafe condition in the unit heater, the thermo-couple 41 will be deenergized and likewise the flow of energizing current in the coil winding will be discontinued and the coil spring 56 will instantly force'the plunger 5! and the left end of link 52 downwardly in a manner to close the valve 32 in the same manner as has been described in connection with the closing of valve 32 by downward movement of the plunger 51. If the valve -82 is closed in this manner, fuel cannot again be supplied to the burner 5 until the electromagnetic device has been manually reset and the device will not remain in its reset position unless the flame of pilot burner H. is again burning satisfactorily. Thus upon pilot flame failure, even if the thermostat H2 then calls for heat, the valve 32 will not be opened. Now if an operative manually relights the pilot burner II, he may attempt to manually reset the electromagnetic device in the following manner. By moving the manual stem 15, as seen on

Fi

1 and 2 and previously described, the lever 14 may be ,rotated in a clockwise direction causing the horizontal lug portion 15' to engage with the nut 5| causing the plunger-51 to be moved downwardy. As will be remembered, part II of the link 52 is now engaged upon the bolt 42 and when plunger 51 is now moved downwardly the link 52 is rotated with the part II fulcrumed upon the head of the bolt 42. By thus forcing the plunger 51 downwardly, the plunger 5! is the gases of combustion within the heater and a relatively high and unsafe value at which heater and adjacent cells I will quickly rise to danger exists of the cells I becoming burned. 75

moved upwardly against the force of coil spring 56 and the electromagnet may be returned to its previous position within the coil winding 45. During the manipulation just described, it, will be understood that the downward force applied to plunger 51 and the reaction of coil are both brought to bear upon the bolt 42 by part II of link 52 and therefore the valve 22 is kept firmly closed. Now if the pilot burner H has not been properly relit or if it has gone out after the operative has relit it, the electromagnet 50 will not stay in its upper position due to the thermocouple 41 not being energized. Consequently, upon the operative, releasing the manual stem 16, the plunger 5| will again move downwardly,

thus maintaining the valve 32 closed in the'manner already described. c

From theabove, it is apparent that no gas whatever may be permitted to pass through the valve 32 after pilot flame failure, nor may any gas pass through valve 32 while an operative attempts to manually reset the mechanism for continued operation. The safety characteristics inherent in the apparatus are therefore obvious, and it will be appreciated by those skilled in the art thatv our apparatus provides positive insurance against, the operative permitting a shot of gas to be admitted to the unit heater before he attempts to manually relight the pilot burner I I by exposing a match or the like thereto.

Referring now to Figure 3 of the drawings, we have shown in. this figure a slightly modified form of our invention in which we employ an ordinary pilotvalve rather than a three-way pilot valve as we have disclosed in-Figure 1. Those .parts of the structure of Figure 3 which are identical with and correspond to similar parts of Figure 1 are numbered the same and those parts of the structure of Figure 3 which are modified are indicated by numerals greater than 200. It will be understood that the device of Figure 3 may be incorporated in the same system or a system similar .to that of Figure 1 utilizing the same control devices. It will be seen that in Figure 3 the lower part of the plunger 251 forms a valve indicated at 202 which cooperates with a seat 203 formed by an opening through which the plunger 251 passes. The valve 202 forms an auxiliary valve and gas may be admitted therethrough to the-interior of the housing 35 in a manner which we will presently explain. Within the body l of the valve is a port 204 which communicates with the inlet chamber 3| of valve 32 and which extends through the diaphragm 38, as shown, through part of the housing 35 and to the opening nicates by a port 201 with a tube 298 correspondin: to the tube 98 of Figure 1 which may lead to an auxiliary pilot burner similar to the auxiliary pilot burner 99 of Figure 1.

Referring to the operation of the modification of Figure 3, with the parts in the position shown the pilot valve member 291 is seated and the valve 202 is open. Thus gas may be communicated from the chamber 3| through the port 204 and the valve 202 to the interior of the housing 35 above the diaphragm 38 to maintain th valve 32 closed. Now in the event that valve member 29l should be lifted 011 of its seat in response to a call for heat by a thermostat or the like, gas pressure will be released from above the diaphragm 38 through the port 295 past the valve seat 293 and through port 201 and tube 298 to the auxiliary pilot burner. Upon release of pressure from above the diaphragm 38, the valve 32 will open with a snap action in the customary manner of diaphragm type valves and gas will failure the valve 32 may be closed in the same through which the plunger 251 extends. An ad-- justable needle valve 205 is .disposed in a part of the port 204 extending through housing 35 and access may be had to this needle valve by means of a screw plug 205 engaging With housmanner as described in connection with the modification of Figure 1, while at the same time the valve 202 is seated by reason of part 2 of link 252 no longer engaging the interior of the housing 35.

Th electromagnetic thermo-couple responsive device may be reset'by reciprocating the plunger 251 downwardly in the same manner as described in connection with Figure" 1. If desired, the mechanism corresponding to the mechanism 65 of.Figure 1 already described may also be used with the device of Figure 3. It willbe seen that in Figure 3, we may employ an ordinary pilot valve rather than one of the three-way type and still in the event of pilot flamefailure valve 202 ing 35, as shown. It will be seen that thelever 252 of Figure 3 has an upper part 2 corre-.

spending to its similar part I I as shown in Figure 1. With the parts in their normal position as seen in Figure 3, part 2 of the link 252 engages with the interior of the housing 35 as shown on the drawing so that the valve 202 is normally maintained in spaced relation from its seat so that gas may pass therethrough. If the'plunger 5| is moved downwardly in the same manner as describedih connection with Figure 1 to close valve 32, part 2 of the link 252 will disengage from the interior of housing 35 thereby permitting spring 62 to move plunger 251 upward slightly and. thus immediately close the valve 202 as well as the valve 32.

The electromagnetic pilot valve unit 281 of Figure 3 is secured to the plate 231 in the same manner as that of Figure 1 having a similar gasket 289 disposed between the flange of the valve body. and the plate portion 231. Number 295 in? dicates a port which extends through a part of the housing 35 through the plate portion 231, through the gasket 289 and through the valve body 288 so as to communicate with the pilot valve chamber 294. The pilot valve member 291 cooperates with a seat 293 and may open or close.

will close thereby cuttingoff any bleed of gas which would permit unburned gases to accumulate in the unit heater.

While we have disclosed two modifications of our invention and pointed out the useful novelty, utility, and advantages thereof, we are aware that various" modifications, variations, and changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention. The disclosed embodiments are therefore to be interpreted as illustrative and the scope of our invention is to be limited only as determined by the appended claims.

We claim as our invention:

1. In a gas fired heating system including a main burner and a pilot burner, a control valve, valve closing means comprising an electromagnetic device normally energized by a thermocouple responsive to the pilot flame, said means being arranged to release upon pilot flame failure for closingthe valve, manual means cooperating with the valve closing means for repositioning the electromagnetic device to its energized position, means for operating said manual means for closing the valve when it is not closed by said electromagnetic device, and a fusible link nermally restraining said operating means but releasing the same for operation upon the attainment of a predetermined high temperature.

2. In a control valve assembly, in combination,

a main valve, means forming a pressure chamber for controlling the main valve, an auxiliary valve for controlling the pressure in said chamber, temperature responsive mechanism operable at a predetermined temperature to close both said main valve and said auxiliary valve, said mechanism being constructed and arranged to act directly on said main valve and manual means cooperating with said mechanism and operable exteriorly of said valve assembly for maintaining said main valve closed, said manual means comprising a plunger formed by an extension of the stem of said auxiliary valve.

3. In a control valve assembly, in combination, a fluid flow control valve, an auxiliary valve associated with said control valve, resilient means urging said auxiliary valve in closing direction, temperature responsive means comprising a movable member) for closing both valves, said means normally holding said auxiliary valve open and at a predetermined temperature moving said movable member in a direction to close said control valve and to cease holding said auxiliary valve open, said auxiliary valve having a reciprocable stem by reciprocation of which said movable member can be moved as a lever fulcrumed upon said control valve for closing said control valve.

condition, and means responsive to a second condition operative upon said second condition assuming a predetermined value to close said valve abruptly independently oi the pressure in said chamber and accordingly independently of said flrst condition.

'7. In a control valve assembly in combination,

a diaphragm type valve, 9. pilot valve for normally controlling the diaphragm valve, normally inactive means responsive to temperature operable to bear upon said diaphragm valve for closing it, said last means comprising a thermocouple and an electromagnetic device energizable thereby.

8. In a control system, in combination, a main burner, a pilot burner, a diaphragm type valve controlling fuel flow to said main burner, .a pilot valve normally controlling said main valve, temperature responsive means adapted to bear against said diaphragm valve for closing it at a predetermined temperature, said means comprising a thermo-couple responsive to the pilot flame and an electromagnetic device energizable thereby, and additional means responsive to heat from said main burner for actuating said first mentioned temperature responsive means for closing 4. In a control valve assembly comprising a valve body, in combination, a diaphragm type flow control valve, a member disposed above the diaphragm means energizable in response to temperature attached to said member for nor-* mally maintaining it in spaced relation to the diaphragm, an auxiliary valve communicating with the space above the diaphragm, said auxiliary valve having a stem forming a plunger extending exteriorly of the valve body, resilient means associated with said plunger urging the auxiliary valve in closing direction, said member cooperating with said auxiliary valve normally keeping it open, said member being operable upon deenergization of said temperature responsive means to close the flow control valve and auxiliary valve, and said plunger being reciprocable to move said member in a manner to close the flow control valve.

5. In a control valve assembly, in combination, a diaphragm type flow control valve, a link member disposed above the diaphragm normally in spaced relation thereto Ior closing the valve,

means iorming a fulcrum above said link member, means pivotally attached to each end of said link, said means at one end of the link comprising a plunger extending exteriorly of the valve, an auxiliary valve communicating with the space above the diaphragm valve, the head'of said auxiliary valve being formed by said plunger, resilient means urging said auxiliary valve in closing direction, said link normally engaging said fulcrum whereby said auxiliary valve is held open, said means at the other end of the link being actuable in response to temperature to move the link out of engagement with said fulcrum for closing the auxiliary valve and to move the link into engagement with the diaphragm for closing the diaphragm valve.

6. In a control valve assembly, in combination, a main valve, a pressure motor comprising a variable pressure chamber and a movable wall connected to said valve, a pilot valve for controlling the pressure in said pressure chamber, means responsive to a first condition controlling said pilot valve thereby to position said main valve in accordance with the value oi said first and means including said main valve means and. v

the diaphragm valve at a predetermined temperature.

9. In a control valve assembly, in combination, a mainvalve, means forming a, pressure chamber for controlling the main valve, a. pilot valve for controlling the pressure in said chamber and hence the position of said main valve, and means responsive to a controlling condition automatically operable at. a predetermined value of said condition to close mechanically both said main valve and said pilot valve independently of the pressure in said chamber whereby flow through both valves is cut ofi.

10. In a control valve assembly, in combina-,

tion, a diaphragm type valve, 3, pilot valve for normally controlling the pressure affecting the diaphragm valve and hence the position thereof, means responsive to a normal controlling condition 'for automatically positioning said pilot valve, means adapted mechanically and abruptly to move said diaphragm valve to closed position independently of the pressure afiecting said valve, releasable means for normally retaining said previously named means in an inactive position, and means responsive to a second condition operative upon said condition assuming a predetermined undesired value to release said releasable means.

11. In combination, a main fluid fuel burner, a pilot burner therefor, main valve means controlling the fiow of fuel to saidmain burner, a valve housing for said valve means having a main passage leading to said burner and an auxiliary passage, an electromagnet, an armature movable into engagement with said electromagnet, means responsive to the presence of a pilot flame for energizing said electromagnet sufficiently to hold said armature in engagement therewith but insufllciently to move it into engagement therewith, means associated with said armature for moving said valve means to a fuel flow preventing position when said armature is released from said electromagnet, resetting means for moving said armature into reengagement with said electromagnet, an auxiliary valve carried by and movable with said resetting means,

said auxiliary valve operable upon actuation of said resetting means to establish communication auxiliary passage,

between the inlet side of said valve means and said auxiliary passage while preventing the flow of fuel through said main passage to said main burner.

12. In combination, a main fluid fuel burner, a pilot burner therefor, main valve means controlling the fiow of fuel to said main burner, a valve housing for said valve means having a main passage leading to said burner and an an electromagnet, an armature movable into engagement with said electromagnet, a thermocouple having its hot junction in the pilot flame for energizing said electromagnet sufliciently to hold said armature in enagement therewith but insufliciently to move it into engagement therewith, means associated with said armature for mechanically moving said valve means to a fuel flow preventing position when said armature is released from said electromagnet, resetting means for moving said armature into reengagement with said electromagnet, an auxiliary valve carried by and movable with said resetting means, and means including said main valve means and said auxiliary valve operable upon actuation of said resetting means to establish communication between the inlet side of said valve means and said auxiliarypassage while preventing the fiow of fuel through said main passage to said main burner.

13. In a control system, in combination, a main valve, 2. pressure motor comprising a variable pressure chamber and a movable wall connected to said valve, pilot valve means normally controlling the operation of said main valve by valve in accordance with the value of said first condition, and means responsive to a second condition for mechanically engaging and closing said main valve, independently or the pressure in said variable pressure chamber, whenever said second condition attains a Dredeterminedvalue.

14. In a control system, in combination, a. main valve, a pressure motor comprising a variable pressure chamber and a movable wallconnected to said valve, pilot valve means normally'controlling the Operation of said main valve by controlling the pressure in said chamber, means responsive to a first condition controlling said pilot valve means to thereby position said main valve in accordance'with the value of said first condition, a movable member in said variable pressure chamber, means biasing said member in a direction to mechanically close the main valve independently of the pressure in said chamber, a second condition responsive means normally retaining said member against its bias but adapted to release the same when said second condition attains a predetermined value, and means for manually resetting said movable member to its original position, said manual reset means including means mechanically holding said main valve closed during the resetting operation independently of the pressure in said chamber.

WILLIAM J. MCGOLDRICK. FREDERICK s. DE'NISON.

. a 7- controlling the pressure in saidchamber, means responsive to a first condition controlling said pilot valve means to thereby position said main.