US3050255A - Double solenoid valve - Google Patents

Description

J. R. WILLSON ETAL 3,050,255

Aug. 21, 1962 DOUBLE SOLENOID VALVE 2 Sheets-Sheet 1 Filed Sept. 11, 1959 V m 5 7 ,w K w w m V v 4 /Z// w v w: Y m P a w 7 Z mw Aug. 21, 1962 J. R. WILLSON ETAL 3,050,255

DOUBLE SOLENOID VALVE Filed Sept. 11, 1959 2 Sheets-Sheet 2 ilnired harem 3,050,255 DOUBLE SOLENOD VALVE James R. Willson and Charles D. Branson, Greensbnrg,

Pa., assignors to RohertshaW-Fulton Controls Company, Richmond, Va, a corporation of Delaware Filed Sept. 11, 1959, Ser. No. 839,522 3 Claims. (Cl. 2361) This invention relates to valves for controlling the flow of air and gas to a burner and more particularly to a means of stepping such flow to the burner.

When the flow of fuel to a burner is operated under thermostatic control, it is desirable to reduce the fuel flow to the burner as the temperature sensed by the thermostat approaches the desired value. Due to their particular construction, some burners will not perform at low input rates. Therefore, it becomes necessary to either modulate or step the flow from full input down to the lowest input that will support combustion and then provide an accelerated movement to an o position. In burners of the primary air type, it is necessary that both air flow and gas flow be stepped or modulated through this range of flows since a reasonably close air to gas ratio must be maintained for proper combustion. Prior attempts to create the desired modulation or stepped flow have produced bulky and expensive devices.

An object of this invention is to provide a simple and inexpensive means of stepping the fuel flow to a burner.

Another object of this invention is to proportion amounts of gas and air to a burner, both at full and partial flow.

Another object of this invention is the provision of a device with adjustment means for both air and gas flow whereby the device may accommodate difierent size' burners.

A further object of this invention is a device which is easily and flexibly installed to allow for variations in mounting alignment.

'In the preferred embodiment of this invention, a casing is provided with a pair of gas passages and an air passage for conducting gas and air to a burner. An electrically operated valve is disposed in each of the gas passages to control the gas flow therethrough. A means is provided for deenergizing one of the electrically operated valves to close the same in response to a first predetermined temperature at the burner whereby only a reduced gas how is provided to the burner. Another means is provided for deenergizing the other electrically operated valve to close the same in response to a second predetermined temperature at the burner to completely terminate gas flow to the burner. A third valve is movably mounted in the air passage and is normally biased into engagement with an abutment means therein to define a partially closed position whereby a reduced air flow is provided to the burner. The third valve is operatively connected to the first deenergized electrically operated valve and is movable to a fully opened position thereby, upon movement of such valve to an open position, for providing a maximum air flow to the burner corresponding to the increased gas flow.

These and other objects and advantages of this invention will become apparent from the following detailed description taken in connection with the accompanying drawings wherein:

FIG. 1 is a plan View of the device embodying this invention connected in its operating circuit;

FIG. 2 is a cross sectional view taken on lines I l-11 of FIG. 1; and

FIG. 3 is a partial longitudinal sectional view taken on lines IlI-lll of FIG. 1 and showing connections to the air andgas manifolds.

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Referring more particularly to the drawings, a control device indicated generally at 10 comprises a casing 12 and a solenoid construction 14. The casing 12 is of a generally rectangular configuration and has a passage 16 extending the length of the casing adjacent the bottom thereof. A relatively smaller passage 18 is located above and parallel to passage 16. The length of passage 18 is less than passage 16 and terminates in a wall of casing 12. A pair of parallel spaced bores 21) and 22, having substantially similar configurations, extend through the top of casing 12 and communicate at right angles with passages 18 and 16. The bores 20 and 22 receive a portion of the solenoid construction 14 in a manner more fully described hereinafter.

A mounting flange 24 is located on one side of casing 12. A small rectangular-shaped gas supply manifold 26 and a larger rectangular-shaped air supply manifold 28 are connected to the mounting flange 24 by any suitable means, such as screws. The gas manifold 26 and the air manifold 28 have openings corresponding to the ends of passages 16 and 18. The ends of passages 16 and 18 have a gas inlet'30 and an air inlet 32, respectively, formed in the casing 12. Gas normally flows from the manitold 26 through inlet 30, passage 18, and down through the lower portions 34 and 36 of bores 20 and 22, to mix with air in passage 16, which has entered from air manifold 28 through air inlet 32. The mixed air and gas then pass through tubing 49, which is loosely disposed in the casing outlet 38, to an appropriate burner (not shown). To form the loose connection for the tubing 48, a substantially annular plate 42, holding in place a resilient ring 46, is fastened about outlet 38 by three screws 44 (only one of which is shown). The ring 46, formed of any suitable resilient material, such as rubber, has an inner diameter which is smaller than the diameter of outlet 33 and is also slightly smaller than the diameter of tubing 41), whereby the tubing may be forced through the ring to provide a fluid-tight flexible connection.

Each of the bores 20 and 22 have means therein to control gas flow through the gas passageways 16 and 18. More particularly, a pair of nuts 48 and 5t) are threadedly received in the upper portion of bores 20 and 22, respectively. A pair of elongated cylindrical armature housings 52 and 54-, having one open end flanged outwardly, are attached by the flange within the nuts 48 and 5t}, respectively. The major portion of the armature housings 52 and 54 extend above the casing 12 and outwardly from the nuts 48 and 50. A pair of armature plungers 56 and 58 of generally cylindrical configuration are disposed within armature housings 52 and 54, respectively, and are adapted for reciprocal movement therein. Armature plungers 56 and 58 have reduced end portions 57 and 59, respectively, upon which are positioned cylindrical valve members 60 and 62. Uponmovement of armature plungers 56 and 58, the cylindrical valve members 60 and 62 engage or disengage annular resilient seats 64 and 66, which are disposed on shoulders formed in the lower reduced portions 34 and 36 of bores 20 and 22.

A pair of solenoid coils 68 and 7 0 actuate the armature plungers 56 and 58 within the housings 52 and 54 between the above stated positions. Suitable covers 72 and 74 are disposed respectively about the solenoid coils 68 and 78. A pair of annular guide plates 76 and 78 are mounted to nuts 48 and 58, respectively, and are cooperable with covers 72 and 74 to position the same on top of casing 12. A substantially rectangular plate 80, having the end portions shaped to accommodate the upper portion of armature housing 52 and 54, is positioned on top of covers 72 and 74 and forms a bridge therebetween. A pair of apertures 82 are spaced closely adjacent to each other in the medial portion of this bridge. One end of a coil spring 84 is hooked to the portion between the aperand 70in position on the casing 12.

. 3 r r tures. The other end of coil spring 84 is' hooked to'the wall of an opening in the casing 12.. The coil spring 84 is mounted intension to secure. the solenoid coils 68 The solenoid coils 68 and 70 each are connected to a pairfof electrical leads 69,71, and 73, 75,,respectively,

extending therefrom and adapted to be connected to an appropriate thermostat switch 77 The thermostat switch 77 has a pair of spaced stationary contacts 79 and 811 which are engageable respectively by a pair of movable contacts .83 and 85. Stationary contact 79 is connected 7 to lead 69 and stationary contact 81 is connected to lead The movable contact 831s carried by the free end of a resilient switch arm 87. The switch arm 87 carries a block of insulating material 95 which is engageable by anexpansible power element 89. The power element 89 is of the conventional type and is filled with a suitable thermal fluid which will expand upon an increase in the temperature sensed by a bulb (not shown), placed adjacent the vessel to be heated by the burner. Movable contact 83 is normally biased into engagement with sta tionary contact 79 but is adapted to be moved out of engagement therewith upon expansion of power element Movable contact 85 is mounted on the free-end of a resilient switch arm 91and is normally biased into engagement with. stationary contact 81. Abutment means 93 is provided on switch arm 91'and is adapted to be engaged by switch arm 87 to move contact 85 out of engagement with stationary contact 81. Leads 71 and 75 of solenoids .68 and7fi are suitably connected in parallel V to a 110 volt power source. Thermostatic switch 77 is connected to leads 69 and .73 of solenoids 68 and 70. From the foregoing, it is apparent that, upon expansion, the power element 89will open contacts 6 9'and 83 to deenergize solenoid 68. Further expansion of power element. 89 will subsequently open contacts 81 and 85 to deenergize solenoid 70. Thus, solenoids 68 and 70 are sequentially deenergized.

18 intermediate bores 20 and 22. the front of casing '12 and communicates with passage 18 'ata point intermediate bores 24? and 22. A plug 90, having a slot 92 on the inner end thereof, is inserted in bore 88 and isadapted'to be rotated by a suitable tool to align or partially align slot 92 with passage 18. A suitable g Toregulate the amount of gas flow to the lower portion 7 7 -36 of the bore 22, a control means is located in passage A bore 38 is located in armature plunger 56 reaches the upperlimit of its'travel, the flapper 1110 is rotated to a position substantially parin assembling the above device, nuts 48 and 51 are.

threaded into bores 20 and 22, respectively, to position the armature housings 52 and 54 on the casing 12. The

solenoid coils 6 8 and 70 are placed over the armature housings 52 and 54, respectively. The rectangular plate St} is placed on the solenoid covers '72 and 74 and the coil spring 84 is mounted in tension between the rectangular plate 89 and the opening 86 in the casing 12 to hold the solenoid coils 68 and 70in place.

Tubing 40, which is connected to a burner, is inserted in 0ut1et38 of the casing 12. The solenoid leads 69,71 and 73, 75 are connected to a power source and the thermostat switch 77. The bulb (not shown) of the f thermostatic power element 89 is positioned adjacent'the vessel to be heated by the burner (not shown) so as to be responsive to the temperature thereof;

initially, the thermostatic power element 89 is con tracted as the temperature of the vessel is below the predetermined heating temperature and the movable contacts 83 and 8-5 are biased into engagement with stationary contacts 7 9 and 31. Thus, electrical energy will be supplied to solenoid-coil 68 through a circuit which can be traced as follows: the 110 volt power source, resilient arm 87, movable contact 83, stationary contact 79, leadfwire 69, solenoid coil 68, and lead wire 71 back to the power source. Similarly, electrical energy is supplied to the coil 70 through a parallel circuit which may be traced as follows: the 110 volt power source, resilient arm 91, movable contact 85, stationary contact 31, lead wire 73, coil 7 70, and lead wire 75 back to the power source.

When the solenoid coils 68 and 70' are energized, the

armatures S6 and 58 will move upwardly from the position shown in FIG. 3 to disengage valve members 60 and V 62 from their respective valve seats 64 and 66. Thus, two

cover screw 94 is threaded into bore 88 over the top of plug 96.. Inadvertent adjustment of the plug 90 is prevented, as the cover screw 94 must be removed to expose I V the plug 90'.

To regulate air flow from the air manifold 28 to passage 16, a pin 96 extends across passage 16 adjacent inlet 32 and has one endrotatably mounted in a cylindrical recess formed in the passage wall and the other end rotatably mounted in a cylindrical recess in screw 98 which is threaded into the casing 12. A substantially elliptical-v shaped flapper 1611 is secured about its conjugate axis to pin 96. .A support member 102 is attached to flapper I :109 on'oneside of the axis and serves as a counterweight parallel gas paths are defined. The first gas path is traced as follows: from gas manifold 26, through inlet 30, past valve seat 64, lower portion 340i bore 20', and into passage 16. The second gas path is traced as follows: from gas manifold 26, through inlet 30, passage18, past valve seat 66, and lower portion 36 of bore 22, into passage 16; Gas from these parallel flow paths will mix in passage 16 witha maximum supply of air flow from'air manifold 28, as the upward movement of armature'56 engaged washer 166 on shaft 104 with the bifurcated end I 163 of member 102 to rotate the flapper valve 100 to a substantially horizontal position inpassage'lfi. Thus, a

to bias the flapper. topartially close passage 16. Member 102 is providedwith a'bifurcated end 103 extending outwardly at an angle from theflapper 101 and around a shaft1104. The shaft 104 extends through the lower portion 34 of bore2l and is secured to the reduced end portion57 of armature plunger 56; A washer 106 is v secured to the end of shaft 104 to engage the bifurcated end 103 .of member 102.

As the armature plunger 56 movesupwardly to disf en'gagevalve member :60 from valve seat 64, shaft 104 'movesupwarcfly'therewith and washer106 engages the bifurcated end 103 ofimember 102., Theengagement of washer. 106 with the bifurcatedend 1113 translates upward movement ofshaft 164 into rotational movement of the flapperlllt); :The arrangement of parts is such that when full capacity of fuel, mixed airand gas, will be supplied to the burner through'tubing 40. A

The heat from the burner acts upon the vessel placed thereon in the usual manner. As the temperature of the vessel approaches the predetermined heating temperature,

power element 89 will expand and engage the insulating block 95 on switch arm 87 to rotate the switcharm in a clockwise direction against the bias thereof to move contact 83 out of engagement with fixed contact 79.

Opening of contacts 79 and 83 will break the circuit f to the solenoid coil 63 to deenergize the samecausing the. closing of the valve member 60. -As valve member 60 returns to its seat 64;W3Sl161 106 ismoved out of engagement with the bifurcated member ltlzfa'nd fiapper valve 10-9, pivots to its partially closed position as; shown in FIG. 3. Contacts 81 and are still in engagement and the coil 76 continuesto beenergized to maintain the valve member 62 in open position; Accordingly, gas only This assembly is' then secured to gas manifold 26 and airmanifold 28. p

passes through valve seat 66 into passage 16 to mix with the reduced flow of air therein. Thus, a low input of fuel is supplied to the burner through tubing 40.

The temperature of the vessel will continue to rise even with the low fuel input to the burner. The temperature rise is sensed by the bulb of the power element 89 and the power element will continue to expand. The continued expansion of the power element 89 moves the switch arm 87 into engagement with abutment means 93 carried by the switch arm 91. When the predetermined heating temperature of the vessel is reached, the power element 89 will have expanded sufliciently to move switch arm 91 against the bias thereof and separate the contacts 81 and 85. Opening of the contacts 81 and 35, opens the circuit to the solenoid coil 70 thereby deenergizing the same and permitting valve member 62 to return to a closed position. This action shuts off all gas supplied to the burner and further heating of the vessel is temporarily prevented.

It will be apparent that if the temperature of the ves sel remains at or above the desired predetermined temperature, the power element 89 will remain sufliciently expanded to bias the switch blades 87 and 91 to positions which separate the contacts 79, 83 and 81, 85 so that both solenoid coils 68 and 70 will remain deenergized, and gas flow through the control device will be prevented. As the temperature of the vessel drops, the power element 89 will contract to permit closing of contacts 81, 85 to once again close the circuit to the solenoid coil 70 thereby opening valve member 62 to again supply a low input of fuel to the burner. Thus, fuel to the burner will be cycled by the repeated energization and deenergization of the solenoid coil 70 as the contacts 81, 85 make and break the circuit to the same.

If the temperature of the vessel drops sufliciently below the desired predetermined heating temperature, or in the event that the reduced fuel input is not suflicient to restore the desired temperature, the power element 89 will contract further to permit closing of contacts 79, 83, thereby completing the circuit to the solenoid coil 68. Energization of coil 68 will actuate valve member 60 and flapper valve 100 to their open positions to thus supply maximum fuel to the burner. Both gas paths through the control device are now supplying maximum fuel flow as both valve members 60 and 62 are in their open position permitting gas to enter passage 16 and mix with the full capacity air flowing past flapper valve 100. Thus, a full capacity input will be supplied to the burner.

When the control device is supplying full capacity flow to the burner, the flow of gas and air is maintained in proper combustible proportions by means of appropriately sized orifices in the gas supply manifold 26 and the air supply manifold 28. The proportion and amount of air and gas flow for the reduced fuel input position is determined by air adjustment screw 108 and gas plug 90. It is apparent that screw 108 and plug 90 may be adjusted so that the control device 10 will meet the requirements of various sized burners.

While only a single embodiment of this invention has been shown and described, it is apparent that there may be many changes in structure as well as operation Without departing from the scope of this invention as defined by the appended claims.

We claim:

1. A control valve assembly for controlling the flow of fuel gas and primary air to a burner comprising a valve housing having a first passage extending therethrough from an air inlet to a valve outlet, means for supplying air to said air inlet, means defining a second passage in said housing extending inwardly of said housing from a gas inlet to an inner end located within said housing, means for supplying fuel gas to said gas inlet, means in said housing defining a first cross passage extending from a point in said first passage adjacent said air inlet to a point in said second passage adjacent said gas inlet, means defining a second cross passage in said housing extending from a point in said first passage adjacent said valve outlet to a point in said second passage adjacent said inner end, a normally energized solenoid controlled valve operable in each cross passage to permit gas to flow from said second passage to said first passage when its solenoid is energized and to block flow of gas through the cross passage when its solenoid is deenergized, an air control valve located in said first passage between said air inlet and said first cross passage for movement between a maximum air flow position and a minimum air flow position, and means coupling said air control valve to the solenoid valve operable in said first cross passage to locate said air control valve in said maximum air flow position when the first cross passage solenoid valve is energized and to locate said air control valve in said minimum air flow position when the first cross passage solenoid valve is deenergized.

2. A control valve assembly as defined in claim 1 further comprising regulating valve means located in said second passage between said first and said second cross passages for adjustably regulating the rate of flow of gas from said gas inlet to said second cross passage.

3. A control valve assembly as defined in claim 1 further comprising temperature responsive means for deenergizing the first cross passage solenoid valve when the temperature sensed by said temperature responsive means exceeds a first selected temperature and for deenergizing the second cross passage solenoid valve when the temperature sensed by said temperature responsive means exceeds a second selected temperature higher than said first selected temperature.

References Cited in the file of this patent UNITED STATES PATENTS 2,025,696 Branche Dec. 24, 1935 2,464,700 Logan Mar. 15, 1949 2,526,069 Douglas Oct. 17, 1950 2,661,157 Reichelderfer Dec. 1, 1953 2,693,914 Payne Nov. 9, 1954 2,885,151 Weber May 5, 1959

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