US2652110A - Diaphragm valve control - Google Patents

Description

Sept, 15, 1953 R. 0. MAIN DIAPHRAGM VALVE CONTROL 3 Sheets-Sheet 1 Filed Dec. 1,. v 1950 N. r .1 R m M m E VC 0 mw w w m o a W h Y B fima g mu gmuwn g m m m Sept. 15, 1953 R. c. MAIN 2,652,110

DIAPHRAGM VALVE CONTROL Filed Dec. 1, 1950 3 Sheets-Sheet 3 INVENTOR. ROBERT C. MHZ/V.

Patented Sept. 15, 1953 DIAPHRAGM VALVE CONTROL Robert 0. Main, Boston, Mass., assignor to Robertshaw-Fulton Controls Company, Greensburg, Pa., a corporation of Delaware Application December 1, 1950, Serial No. 198,516

6 Claims. 1

This invention relates to a valve control to be employed in conjunction with main and pilot burners to b safely lighted and controlled to maintain a desired temperature in a space to be heated. More particularly, the system includes electric ignition for the pilot burner and control of fuel supply to the main burner by the pilot burner, the supply of fuel to which is thermastatically controlled.

A preferred embodiment of the invention coinprises a momentary bleed type diaphragm valve adapted for controlling fuel flow to the main burner and having the automatic and igniter control associated therewith as a separate unit. The outlet to the pilot burner is controlled by the first of a pair of control valves. An electromagnetic type actuator overns the position of the first control valve in accordance with temperature conditions in the space to be heated.

The second control valve controls both the admission of fluid under pressure to the pressure chamber of the diaphragm valve and the exhaust of fluid under pressure therefrom. This second control valve is governed by an expansible element responsive to a flame at the pilot burner,

movement of the expansible element being transmitted to the control valve through a snap-action mechanism to cause opening and closing of the diaphragm valve for controlling the main burner in accordance with the presence or absence of flame at the pilot burner.

It will be apparent from the foregoing brief description that among the objects of the invention is the complete control of the main and pilot burners by a mechanism operating in conjunction with a standard form of diaphragm valve.

Another object of the invention is to insure safe lighting of the pilot burner by maintaining the diaphragm valve closed in the absence of flame at the pilot burner.

Another object of the invention is to embody the device having the operational features and functions described in a small compact unit incorporating interchangeable parts.

Other objects and advantages of the invention will be apparent from the accompanying specification and claims taken in connection with the drawings, wherein:

Fig. 1 is a sectional schematic view of the valve control of this invention employed in conjunction with a fuel burner installation;

Fig. 2 is a sectional schematic view of the valve control of Fig. 1 with the parts thereof shown in different operating positions;

Fig. 3 is an enlarged plan view of a detail;

Fig. 4 is a section taken on line IV-IV of Fig. 3 looking in the direction of the arrows;

Fig. 5 is a view taken on the line VV of Fig. 4 looking in the direction of the arrows; and

Fig, 6 is an enlarged section taken on the line VI-VI of Fig. 1.

Referring more particularly to Fig. 1 of the drawings, a main fuel burner IE is shown as being supplied with fuel by a main fuel pipe H2 in which is interposed a diaphragm valve [8 of the momentary bleed type having a valve seat l8 and cooperating valve member 20 for controlling flow of fuel to the main burner It.

The diaphragm valve is is provided with a bonnet 22 having an opening 24 therein. A flexible diaphragm 26 is secured in position by the bonnet 22 and serves as the actuating means for the valve member 28. The opening 24 communicates with the space between the bonnet 22 and the diaphragm 26 which forms a pressure chamber 28.

A pilot burner 30 and a bleed fuel burner 32 are shown as associated with the main burner it). These burners 30 and 32 receiv fuel by way of conduits 34 and 36 respectively connected to the valve controldevice of. this invention, the valve control device being disignated generally by the reference numeral 40. A pilot supply conduit 42 for the valve control device 40 communicates with the main fuel pip I2.

An electric igniter 46 of the hot wire type is located in lighting proximity to the pilot burner 38-. The igniter 46 maybe energized through a step-down transformer '48 from a suitable source of commercial current supply indicated by the line wires LI and L2. The electric circuit from this source will be described more particularly in connection with the operation of the valve control device 4%] and may include the usual room thermostat 59 which opens its contacts on a rise in temperature.

Diaphragm valve control The diaphragm Valve control 6.0 will now be described in detail and is clearly shown in Figs. 1 and 2.

The valve control 46 comprises a main casing 54 having a central opening 56 in its underside which is adapted for communication with the opening 24 and the diaphragm valve it by means of a nippl connection 58 which also-serves to connect the parts together. The casing 53 houses a plurality of control valve means for controlling the operation of the diaphragm valve member l E to afford an automatic shut-off of fuel supply to 3 the main burner I in the event of extinguishment of the flame at the pilot burner 35 and also to control the supply of fuel to the main burner It in accordance with temperature conditions as sensed by the room thermostat 50.

To this end, a first control valve means, designated generally by the reference numeral 60 is provided at the left-hand side of the casing 54 as viewed in the drawings and comprises a valve chamber 62 provided with a valve seat 64. A ball valve member 66 is reciprocal in the valve chamber 62 and is biased into engagement with the seat 64 by a coil spring 68. A valve stem 1B projects from the valve member 66 past the valve seat 65 to the exterior of the casing 54. Suitable sealing means such as a flexible diaphragm I2 is provided at the projecting end of the valve stem for sealing the casing 54 against leakage at this point A second control valve means, designated generally by the reference numeral 14 is located in the casing 54 laterally of the first control valve means 65 and comprises a valve chamber it having a pair of axially aligned valve seats I8, 85 at opposite ends thereof. A ball valve member 82 is reciprocal in the valve chamber I6 for cooperation alternatively with the valve seats I8, 86 and is biased into engagement with the seat '58 by a coil spring 84. A valve stem 86 projects from the valve member 82 past the valve seat I8 to the exterior of the casing 54. Suitable sealing means such as a flexible diaphragm 88 is provided at the projecting end of the valve stem 86 for sealing the casing 54 against leakage at this point.

A lateral extension 90 formed on the casing 54 supports a thermally responsive device comprising the usual expansible element 92, capillary tube 54 and bulb 96 which is located to be heated by a flame from the pilot burner 30. The expansible element 92 is provided with a thrust button 98 in operative engagement with a snap-action mechanism, designated generally by the reference numeral I00, through which movement of the expansible element is transmitted to the valve stem 86 as will more fully appear. A cover I02 extends across the casing 54 for enclosing the valve mechanism therein.

The snap-action mechanism ISO is best shown in Figs. 1, 2 and 6 and may comprise a main lever I84 mounted substantially horizontally above the expansible element 92. One end of the main lever IE4 is provided with knife edges I96 for cooperation with a bearing I08 carried by the cover I02. A depressed portion H0 is formed in the main lever I54 for receiving the end of the thrust button 98, movement of which will rotate the main lever about its bearing I08. The other end of the main lever I04 is grooved at H2 to receive the end of a coil spring II4 which passes through a suitable recess I'I3 formed in the main lever I54.

A bifurcated secondary lever H6 is provided at one end with knife edges II8 cooperable with bearings I carried by the cover I02. The legs of the bifurcated portion of the secondary lever IIG pass on either side of the main lever H34 and its bearing I08 and are connected at a medial point by a bridge I22 which passes beneath the main lever I04. The coil spring H4 is hooked into a hole I24 formed in the bridge I22 so that the tension of the spring I I4 will bias the knifeedges I06, II8 of the levers I04, IIfiinto engagement with their respective bearings The end of the secondary lever I Ifioppositethe knife edges I I8 is provided with a depressed portion I26 which forms a bearing surface for engagement with the end of the valve stem 86. Thus movement of the secondary lever I I5 about it knife edges IIS will cause movement of the valve stem 85.

When the snap-action mechanism ISO is in the position shown in Fig. 1 and the expansible element 92 expands to move the thrust button 98 upward, the main lever I64 is moved counterclockwise about its bearing I08. The tension spring I14 will also be rotated counterclockwise about its end which is hooked to the bridge I22 of the secondary lever I I6. When the center line of the spring IIfi crosses the plane defined by the knife edges H5 and the bridge I22, the spring II! will snap the free end of the secondary lever [I5 upward.

The secondary lever H5 is so designed that when its free end is snapped upward, the bridge I22 to which the spring I I4 is connected will remain below a line between the bearing I08 of the main lever and the bearings H8 of the secondary lever. Thus, when the free end of the secondary lever is at the upward extent of its movement the spring II4 will tend to rotate the main lever I54 clockwise about its bearing I08 when thrust button 98 is withdrawn.

It will be understood that other forms of snap-acting mechanisms different from that herein described may be used in the present invention.

The lateral extension carries a double throw switch I35 having a switch arm I32 biased into engagement with a first contact I34. The switch arm IE2 is arranged to be engaged by a pin I35 depending from the free end of the main lever of the snap-action mechanism I00 to be moved against its bias into engagement with a second contact I33.

Operating means for the first control valve means 68 may comprise a pivoted armature I40 of a control relay I42, the free end of the armature I49 overlying the first control valve means 6i! for operation thereof on energization of the winding I 44 of the relay I42. As will be hereinafter apparent, the control relay I42 receives electric energy from the commercial source Ll, L2 and is subject to energization and deenergization by operation of the room thermostat 50.

A lever mechanism, shown more clearly in Figs. 3, 4 and 5 of the drawings, is provided for manual operation of the first control valve means 65 in the event of an electric power failure. Positioned adjacent the first control valve means 60 is a frame member I50 of sheet material carrying at one end of a pair of upstanding arms I52 to which an insulating member I54 is secured. A pair of contacts I56 is arranged in spaced relation on the insulating member I54 for engagement by a pivoted operating arm I58 to close a circuit therethrough. The operating arm E58 extends from the exterior of the cover I02 across the frame [5B and terminates in a pair of knife edges I50 which engage with knifeedge bearings I82 upstanding from the frame I55. One end of a coil spring member I54 engages with a wall of an aperture I66 formed in the operating arm I58 while the opposite end thereof is engaged with the wall of an aperture I68 formed in the end wall I'IU of the frame I515. The arrangement provides a simple over-center snap-action device as will be apparent to those skilled in the art.

A lever member I12 is pivoted intermediate-its ends on a support I14 forming a partial side wall for the frame I50. One end of the lever member I12 is interposed between the free end of the pivoted armature I40 and the first control valve means 80. lever member I12 is supported on a shaft I16 projecting substantially perpendicularly from the operating arm I58 and is adapted to rotate the lever member I12 on its pivot I14 when the operating arm I58 is manually operated as will hereinafter be described. A reduced end of the shaft I projects through the lever member I12 into operative engagement with a projection I11 on the relay armature I40 whenever the operating arm I58 is in its upward operating position as shown in Figs. 4 and 5 of the drawings.

The two control valve means 60 and 14 of this invention are adapted to control the flow of fuel to various passages formed in the casing 54 depending on the positions which these valves assume. Thus, one passage I18 of a pair of passages formed in the casing 54 serves as an exhaust for the pressure chamber 28 and may be traced on Fig. l, for example, from the opening 56 to the valve chamber 16 of the second control valve means 14; past the lower valve seat 80 therein; and through the casing 54 to the connection of the conduit 33 for the bleed pilot burner 32.

The other passage I80 of the pair forms the main inlet for fuel to all the various passages in the casing 54. Thus, passage I80 serves as the inlet to the pressure chamber 28 and may be traced on either Fig. 1 or 2 from the connection of the pilot supply conduit 42 at the left-hand side of the casing 54, past the valve seat 18 to the valve chamber 16 of the second control valve means 14; and from the valve chamber 16 to the opening 53 which communicates with the opening 24 in the diaphragm valve bonnet member 22.

A third passage I82 serves to supply fuel to the pilot burner 30 and may be traced on either Figs. 1 or 2 from the passage I80 to the valve chamber 62 of the first control valve means 60; past the valve seat 64 of the first control valve means 60; and through the casing 54 to the connection of the conduit 34 for the pilot burner 30.

Operation The various elements are shown in Fig. 1 of the drawings in the positions which they assume when the main burner I0 is shut off and the pilot burner 30 is extinguished. If, when the apparatus is in the condition shown in Fig. 1, fuel under pressure is admitted to the main fuel pipe I2, fuel will flow through the pilot conduit 42, and the passage I30, past the valve seat 18 to the chamber 16 of the second control valve 14, and thence to the opening it in the casing 54. Since the second control valve means is held against its bias with the ball valve member seated on the seat 80, the exhaust passage I13 is closed at this point and no fuel can escape to the bleed pilot burner 32. The first control valve means 00 may be either in its biased position or otherwise at this time depending on the condition of the room thermostat 50. The pressure now builds up in the pressure chamber 28 and serves to maintain the diaphragm valve member 20 in closed position relative to the valve seat I8.

Assuming that the thermostat 50 is calling for heat, then the contacts thereof become closed. Such operation establishes a circuit for the relay I42 which may be traced as follows: line wire LI,

The opposite end of the 6 wire I84, relay winding I44, wire I86, wire 200, and contacts of thermostat 50 to line wire L2.

Energization of the winding E44 will cause the pivoted armature I40 to engage the first control valve means 60 and move the ball valve member 66 thereof out of engagement with the seat 64 to the position shown in Fig. .2. Consequently, the passage I82 is open for transmission of fuel from the passage I by way of the valve chamber 62, past the valve seat 64, through the casing 54 to the connection of the conduit 34 for the pilot burner 30.

Closing of the contacts of the thermostat 50 upon a demand for heat will also cause energization of the igniter 40 by completing a circuit as follows: line wire LI, primary winding of the transformer 48, wire I88, contact I38 of the double throw switch I30, switch arm I32, wire I90, wire 200, andcontacts of thermostat 50 to line wire L2. Energization of the primary winding of the transformer 48 will induce a current flow in the secondary winding thereof and the igniter 46 will be energized through a circuit as follows: Lower terminal of the secondary winding of the transformer 48, wire I92, igniter element 45, and wire I94 to the upper terminal of the secondary winding of the transformer 48.

Since the closing of the contacts of the thermostat 50 upon a demand for heat causes the first control valve means 60 to assume a position permitting flow of fuel to the pilot burner 30 and also causes the energization of the igniter 46, it will be apparent that the closing of the contacts of the thermostat 50 will result in a flame being produced at the pilot burner 30. When a flame is present at the pilot burner 30 the bulb 96 will be heated thereby to cause expansion of the expans-ible element 92 and upward movement of the thrust button 93. As hereinbefore pointed out, upward movement of the thrust button will cause counterclockwise rotation of the lever I04 and upward movement of the free end of the lever I It with a snap-action. Such movement of the levers I04, H6 will cause the snap-action mechanism I00, the second control valve means 14, and the double throw switch I30 to assume the positions shown in Fig. 2; more specifically, the ball valve member 82 will be in its biased position and seated on the valve seat 18 and the switch arm I32 will be in engagement with the contact I 34.

With the parts of the second control valve means in the positions shown in Fig. 2 of the drawings, supply of fluid fuel under pressure to the pressure chamber 28 from the pilot supply conduit is prevented and'the passage I13 is open for exhaust of fluid from the chamber 28 by way of the openings 24 and 56, passage I18 past valve seat 80 of the second control valve means 14, and through the casing 55 to the connection of the bleed conduit 36. The small amount of fuel thus exhausted is consumed at the bleed burner 32 and is momentary only.

Inasmuch as the chamber 28 now contains no fuel under pressure, the diaphragm valve member 20 is raised from engagement with the valve seat I8 of the diaphragm valve It by the line pressure existing in the main fuel supply pipe I2. The main burner It now receives a supply of fuel which is ignited by the flame from the pilot burner 30 and the system remains in operation until the room thermostat 50 opens its contacts upon a sufiicient rise in temperature.

When the switch arm I32 of the double throw switch I30 is permitted to move to the positions shown in Fig. 2 where itis in contact with the contact I34, the circuit hereinbefore described which includes the primary winding of the transformer 48 is broken thus, deenergizing the igniter 46, and a second indicating circuit is completed which may be traced as follows: line wire LI, wire I96, an indicating .lamp I98, wire 202, wire 204, contact I34, switch arm I32, wire .IQI], wire 289, and contacts of the thermostat 59 to line wire L2. Since the last traced circuit can be completed only when the expansible element 92 is in its expanded condition, it will be apparent that the lamp I98 will be effective to indicate the presence or absence of flame at the pilot burner 30.

When the relay I42 becomes deenergized by opening of the contacts of the room thermostat 50, the relay armature I40 will return to its released position and the first control valve means will return to its biased position with the ball valve member 66 in engagement with the valve seat '84 as shown in Fig. 1 of the drawings. Consequently, the flow of fuel to the pilot burner 30 is cut off and the pilot flame extinguished. Extinguishment of the fiame at the pilot burner 38 will permit the bulb 96 to cool and the expansible element 92 to contract thus causing a downward movement of the thrust button 98. As hereinbefore pointed out, downward movement of the thrust button 98 will permit the snap-action mechanism to assume its original position as shown in Fig. 1 with the lever H6 holding the second control valve means against its bias with the ball valve member 82 seated on the seat 80. Consequently, the bleed outlet is closed and fuel pressure is permitted to build up in the pressure chamber 28 until the diaphragm 20 moves into engagement with the valve seat It. Hence the flow of fuel to the main burner I is cut off by operation of the room thermostat 50.

It will be apparent that the diaphragm valve member 28 will be moved into engagement with the valve seat 58 in the manner described above whenever the flame at the pilot burner 39 is extinguished regardless of the condition of the thermostat 53.

In the event it is desired to operate the system without regard to the temperature of the space to be heated, means have been provided to insure continuous running of the main burner ID by manual operation. Referring more praticularly to Figs. 3, i and of the drawings, it will be apparent that raising the operating lever I58 to the position shown in Fig. l, for example, will serve to close the contacts I55 and also move the lever 72 sufliciently to overcome the bias of the first control valve means 63. As such opcration of the lever IE3 is beyond its dead center point, the overcenter spring I64 comes into operation to retain the lever 58 in its raised position. The parts are thus manually brought to the position shown in Fig. 2 insofar as the first control valve means is concerned. Also, with the contacts I56 closed, the thermostat 50 is shunted out by wires 203, contacts I56, and wire 205. Thus, fuel may be admitted to the pilot burner 33 and be ignited by the igniter 46, the resulting flame being effective to cause actuation of the second control valve means and the exhaust of the fluid pressure existing in chamber 28 to permit the diaphragm valve member to move to its open position to supply fuel to the main burner It as in normal operation.

In the event-of a failure of electric power, the

operating .lever IEBmay be raised to the position shown in Fig. 4 to move the lever I'I2 sufilciently to overcome the bias of the first control valve means 68. As hereinbefore pointed out, the construction of the lever I12 is such that it will remain in the raised position and when in such position fuel will flow to the pilot burner 30 where it may be ignited by a match or the like. When a flame is established at the pilot burner 30, opening of the diaphragm valve will be effected in the manner hereinbefore set forth.

Upon restoration of electric power after manual operation of the lever I58, the relay M2 is immediately energized irrespective of the position of the contacts of the room thermostat 58. Such energization of the relay Hi2 occurs due to the prior completion of the shunting circuit through the contacts 53 by operation of the lever I58. However, when the relay armature I l-3 is attracted by the relay I62, the projection I7? thereon moves into engagement with the projecting end of the shaft I76 to force the lever I58 downwardly past its dead center position with snap-action as is usual in such construction. Thus, the device is automatically reset upon the resumption of electric current supply without attention on the part of the operator. It should be observed that during manual operation of the control in the absence of power supply that the safety shut-off for the main burner I0 remains operative since the actuating means therefor derive their power from the flame at the pilot burner 32;.

Since the only fuel which is conveyed through the novel diaphragm valve control is that required for supplying the pilot burner 38 and the momentary bleed burner 32, it is apparent that the fuel capacity of the device is relatively insignificant. Moreover, the valve control is readily installed on various standard forms of diaphragm valve and can be used to control gas appliances of any size.

Although a specific embodiment of the invention has been shown and described, it will be apparent that many modifications may be made by those skilled in the art. Such modifications may be made in the details of construction and arrangement of parts without departing from the scope of the invention and said claims.

It is claimed and desired to secure by Letters Patent:

1. In combination with a diaphragm valve having a fluid pressure chamber, a casing having an opening adapted for communication with said chamber, said casing having a pair of passages therein one of which communicates with said opening for exhaust of fluid from said chamber, the other passage of said pair providing an inlet for fluid under pressure in said casing and communicating with said opening, said casing having a third passage therein communicating with said other passage and providing an outlet for fluid under pressure from said casing, first conrol valve means biased to a position for closing said outlet, second control valve means having a first position for cutting oif communication between said opening and said other passage and movable to a secondposition for cutting off communication between said opening and said one passage, first operating means movable to one position for overcoming the bias of said first control valve means for opening said outlet, and second operating means for selectively positioning said second control valve means in one of its said positions.

2. Valve control as claimed in claim 1 wherein means cooperable with said first control valve means are provided for conditioning said second operating means to position said second control valve means in said second position while said first control valve means is in its biased position for closing said outlet.

3. Valve control as claimed in claim 1 wherein means cooperable with said first control valve means are provided for conditioning said second operating means to position said second control valve means in said first position while said first control valve means is in a position overcoming the bias thereof for opening said outlet.

1. In combination with a diaphragm valve having a fluid pressure chamber, a casing having an opening adapted for communication with said chamber, said casing having a pair of passages therein one of which communicates with said opening for exhaust of fluid from said chamber, the other passage of said pair providing an inlet for fluid under pressure in said casing and communicating with said opening, said casing having a third passage therein communicating with said other passage and providing an outlet for fluid under pressure, first control valve means operable between positions for opening or closing said outlet, means cooperable with said first control valve means for creating a temperature condition when said control valve means is positioned for opening said outlet, second control valve means having a first controlling position for closing said other passage and opening said one passage and a second controlling position for closing said one passage and opening said other passage, operating means responsive to said condition for selectively positioning said second control valve means in one of said controlling positions.

5. Valve control as claimed in claim 4 wherein said operating means is efiective to position said second control valve means in said first controlling position in the presence of said condition and in said second controlling position in the absence of said condition.

6. Valve control as claimed in claim 4 wherein said operating means includes an expansible element operatively associated with said second control valve means for positioning said second control valve means in said first controlling position upon expansion of said expansible element.

ROBERT C. MAIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,161,248 Denison et al. June 6, 1939 2,363,063 Hildebrecht Nov. 21, 1944 2,374,459 Roberts et al. Apr. 24, 1945 2,513,705 Arden July 4, 1950

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