US2741266A - Valve structure - Google Patents

Description

April 10, 1956 R. D. GRAYSON 2,741,266

VALVE STRUCTURE Filed Jan. 24, 1955 FULLY OPEN CLOSED INVENTOR, L A M/MM 0. (f/mma/v BY F 5 ATTORNEY United States Patent:

VALVE STRUCTURE Richard D. Grayson, La Canada, Calif., assignor to General Controls Co., Glendale, Calili, a corporation of California Application January 24, 1955, Serial No. 483,683

13 Claims. (Cl. 137-628) This invention relates to valve structures of the type more particularly adapted for controlling supply of fuel gas to heating equipment and including thermostatically operated valve means for maintaining an even temperature in a space, such as a room or oven, heated by the equipment.

The invention of the present application has substantially the same objects as those of the invention disclosed in my copending application Serial No. 476,633, filed De.- cember 21, 1954,'but employs a basically different arrangement of parts.

An object of this invention is to provide a thermostatically operated valve structure which includes a pair of valves interconnected in series to control fiow of gas from an inlet to a main outlet, both or" the valves being open when the space temperature is considerably lower than that desired so that a high-fire condition of the equipment-burner is established; the valves being arranged for sequential operation and so that with rise or" space temperature the main-outlet one of the valves is closed and gas then passes from the inlet through a restricted outlet, provided between the valves, to produce a low-fire condition; continued rise of space temperature, it' such should occur despite the low-fire, effecting closing of the inlet valve and thereby complete shut-off of the gas.

Another object of the invention is to provide a valve structure of the character described wherein the mainoutlet one of the valves is arranged to throttle or modulate the fiow of gas, and the inlet valve is of the snapaction type.

Another object is to provide an arrangement whereby, in subsequent opening of the valves in response to fall of space temperature, the main-outlet one of the valves is partially opened before the inlet valve opens so that gas at relatively high rate (sufiicient to ensure lighting of the burner) can pass through the partially-open mainoutlet valve, as well as through the restricted outlet, when the inlet valve opens.

For full understanding of the invention, and further appreciation of its objects and advantages, reference is to be had to the following detailed description and accompanying drawing, and to the appended claims.

In the drawing:

Figures 1 through are diagrammatic sectional views of a valve structure embodying this invention and particularly adapted for controlling supply of gas to the burner of a domestic space-heater. The parts are shown in Figs. 2 and 3 in positions assumed in the closing cycle of the valves, and in Figs. 4, 5 and 1 in positions assumed in the opening cycle.

Referring first more particularly to Fig. l, the numeral 11 indicates an elongated casing having at its right an inlet opening 12 and inlet chamber 13, and at its other end an outlet chamber 14 and outlet opening 15, these chambers being defined in part by a plate 16 covering the top of the casing. Leading downwardly from the chambers 13 and 14, respectively, is an inlet port 17 and an outlet port 18. At their lower ends these ports F ice are interconnected by an elongated chamber 19 defined in part by a plate 20 covering the bottom of the casing.

For controlling flow through the inlet port 17 there is a disk-shaped closure 21 cooperable with a valve seat 22 around that port, there being a similar closure 23 cooperable with a valve seat 24 around the outlet port 18. The seating surface of the inlet closure 21 is preferably provided with a soft facing of rubber or the like, as is indicated by the heavy line.

Projecting centrally from the underside of the inlet closure 21 is a stem 25 which is connected at its lower end to the central part of an apertured snap-disk 26 disposed in a symmetrical enlargement of port 17 and with its margin abutting a shoulder therein. Snap-disk 26 is resilient and serves to bias closure 21 to seated position, the normal shape of the disk being such that its top surface is concave as shown in Fig. 3. Compressed between plate 16 and the top of closure 21 is a light stabilizing spring 27 whose effect can be ignored in connection with the operation of the valves.

The outlet closure'23 is biased to seated position, as shown in Fig. 3, by the force or a helical spring 28 compressed between it and plate 16. Within a cup-shaped housing 29, secured to plate 16, are additional means cooperating with closure 23 and whose purposewill be described hereinafter. These means comprise a pin'3il engageable with the closure and projectable through an opening in the end wallof the housing under the force of a spring 31. The extent of projection of pin 30 is limited by a head formed on its inner end, so that there is clearance between the pin and the closure when the same is seated, as can be seen in Figs. 2 and 3.

For producing force for actuating the valve closures 21 and23 there is shown, by way of example, a fluid pres sure motor comprising an expansible-contractible bellows disposed in a recess between chambers 13 and 14, and an interconnected thermal bulb 36 which, it will be as sumed, is arranged to respond to variations of the temperature of a space heated by apparatus supplied with fuel gas by way of the valve structure.

The bellows 35 is interposed between an adjusting screw 37, threaded in an opening through plate 16, and a stem member 38 which projects sealingly into chamber 19 and is loaded by a stilt spring 39 in a recess in a thickened portion 40 of plate 20. The stem member 38 is slotted to receive an arm 41 which extends lengthwise of chamber 19 and is pivoted intermediate its ends on a pin 42 fixed to the stem.

Ann 41 is arranged so that a projection 43 on the right end of the arm engages the central part of an apertured disk 44 having a knife-edged annulus 45 which bears again the snap-disk 26 adjacent its periphery. The left end of arm 41 engages the tip of a stem 46 projecting downwardly from closure 23 and guided in an opening through the hub of a spider 47 in port 18. It is to be understood that means, not shown, are provided for preventing rotation of the stem 38 and arm 41.. The chamber 19 which interconnects ports 17 and 18 is continuously in communication with the main-outlet opening 15 by way of a restricted passage 48, the rate of flow through which can be adjusted by manipulation of a rotary valve plug 49.

The parts are shown in Fig. 1 in the positions assumed when the temperature at the thermal bulb is low and bellows 35 contracted so that stem 33 is raised under the force of spring 39 and, through arm 41, both of the closures 21 and 23 are raised to fully-open position. The path of flow through the casing is then (as indicated by the flow arrows) from inlet 12 through port 17 and the apertures of snap-disk 26 and disk 44 to chamber 19, and thence through port 18 (and passage 48) to the main outlet 15.

i i Fi closing ari'dfreopening cycles it will be assumed, :by way 7 of example, that the force oieach of springs 28 and 31 is l,0#, and that while the resilient forcetof, snapadisk izo biasing closure '21 .to seated positionwis .-.only 4#,-.the force Areguired to snap .ithe disk: to its closureunseating position islla. I-As was mentioned above, tthet forceof spring ishnegligible. .Spring-39iserves tostore force for actuating, the valves .to open :position' when the bellows contracts and is stifi enough toxefiect positive followthrough of stem. 38.

V In Fig. 2 the bellows 35 isshownsomewhat expanded response to rise of space temperature-so that-stem 38 ist depressed sufiiciently to permit-closure 2 310 seatunder the l-%) forcetof spring 28, the component of actuating force-of spring 39 applied throngharm 4i and di'sk44 to;.-thejsnap.- disk 26nthen vbeing, -however, great er than the -(4#) resilient forceof the snap-disk so that the inlet closuref21remains open. Under-these conditions flow through the casing-is by way of .the restricted passage 48 i only, the adjusted rate of this flow. beingsuch that a :lowa fire-conditionof the heating apparatus is established.

If the space temperature then risesides'pite the small amount of heat produced by the low-fire, farther expansion of the-bellowsand depression of stem 38 results, so

thatthe force applied to the snapadisk is reduced sufficiently to permit ittto assume {its normal shape and snap :the inletclosure .21 onto its seat. .All .fiow through the casingv is then'obstructed. This condition is shown Theparts areshown in Fig. 4' in the positions assumed when, in response to subsequent fall oi the space temperaa tune, the bellows has contracted and stem 38'has risen toa positionzwherein the component of .actuatingforce tap plied to closure '23 :is slightly greater than the (105%) opposing'force of spring- 28 sothat closure v23 is unseated. Inasmuch as arm 41 is operatively balanced-about its pivot,-. an-equal component of the tactuatingiforce is L-ap pliedto the snap-disk,-but the magnitude :of thistforcecomponent is less thanthe' (11:?) force required to snap the disk .toclosure-unseating position so .thatzflow through the casing is still obstructed. The extent of .openingof outlet closure 23 is limited by its engagement with pin 30 whose upward movement is resistediby the (10#) force 7 of spring 31.

In Fig. 5 thesnap-disk is shown as'. having snapped upwardly over-center in response to. farther-contraction er the bellows and resultantiincreaseiof the actuating force beyond-the (ll'#)tamountsrequired to efiect such aetion. 'In spite of the increase of actuating force, closure I 23 is still approximately in the same partially open condition asaini Fig. 4 due to the slight counterclockwise rockingziofv-arm 41"which accompaniedthe snap-action. ThepinLSO. is "arranged-so that the extent deepening of outlet closure..23 is such :hatthe amount or gas 'flovizirfrg p ast:-it,"and through therestricted passage '48, when the inleticlosure 21 snaps open is sufficient 'to'ensure' lighting of the heating-apparatus burner bya pilot burner or other ignitingmeans.

'withts'till farther contraction o'f then-110m "theorem a closure lSJfOICBd to wider open'positiomagainst the "com bined 'fOICflS of springs 28'and31. 'Under cold=weatlier conditions the operation is usually'su'ch ithat closure 23 modulates between its fully-open 'or high fire" -position of .Fig. 1 and its closed position of fig. 2"(wliereinfuel is supplied at low-fire rate through passage 48) in"accord-t opening ofth'e outlet valve prior to opening of the inlet 'valve could be effected by arranging 'the limited-travel spring-loaded pin (corresponding to pin in the same manner as in said copending application.

The arm 41 could be pivoted at a point other then equidistant from the axes ofth e closures as shown. It would then be neccssaryonly Io'jsubstitute springs having values such that the resultants of the actuating and biasiing'forces have the same general relation as in the arrangement described. I p x The means for limiting initial opening ofth'e outlet closure v(spring-loaded pin 30) iisinotessential andwould be eliminated. (If, for. example, spring 28 were of the kind having a high rate of change of force, the operation of the valves would be substantially the same in thetabsence of pin 30 and spring 31. t

The illustrated embodiment" of this. invention is obviously susceptible of 'further modification without/departing from thespirit of the invention, and I- intend there.- -fore to be limited onlybywthe scope of' the appended claims.

I claim as my invention:

1.-In a valve structure: a casing having 'au inletport, an outlet port, and a chamberv interconnecting -the ports; a pair of valves cooperating with 'saidports individually, and movable between open and closed positionstg means biasing each of said valves to a like one-of js'aidpo'sition's; means movable graduallyxin response :to 'varia'tion of a controllingcondition and capable of producing force' for actuating the valves against'the force offitheir bias and means for applying said actuating force -to -bo'th of :me valves gconcurrently, said force-applying rneans being yieldableso that the force eifective-toactuate each valve is determinedby the amount of tactuating force'applied said inlet port and movable between port-opening and port-closing positions; means biasing. eachof said valves to -a like one of said positionsymeans movable gradually V in-response to variation of a controlling'wcondition and capable of producing force for actuating the valves against the force-oftheir bias; and means for'dividing s'aid actuating .force' into 1 two components -'and for applying one 7 component to each of the {valves concurrently, said force-applying means being" yieldable so -that the force eflective'to actuate each valveqis determined by the-componentiof actuating force 'applied to the valve relative totheresistance of the valve to movement; the arrangef ment being such that the force etfectiveito aemate saidt firstvalveto closed position is less than theforce effective'to actuate'said second valveto closed position so thatgin the closing cycle of the valves,-' fiuid can flow through said inletport to' said restricted outlet'whilesaid main-outlet port is closed.

3'. In a valve, structure:

a chamber interconnecting 'the;ports"; "said" casing having also a'restricted outlet communicating" with said'ichamher V intermediatesaid ports; means on'the casing forming a first valve seat around said main-outlet port and a second valve seat around .said inlet port; a first and a second closure cooperable respectively with said 'first and said second seat to'tonn therewith aIfirst' and a secondvalve,

said "closures being movable in opposite direch' ons into and out of engagement with the seats tozcontrol fiow through the respectivelportsg means biasingcach otasaid clo'sures'in alike one of said directions; .rneans.movable t gradually in' response to variation ofatcontrolling condi- 'a casing having, as; 'tlovv' through the casing, an inlet port, a main outletp'ort, and

tion and capable of producing force for actuating said closures against the force of their bias; and means for dividing said actuating force into two components and for applying one component to each of the closures concurrently, said force-applying means being yieldable so that the force effective to actuate each closure is determined by the component of actuating force applied to the closure relative to the resistance of the closure to moveent; the arrangement being such that the force effective to actuate said first closure to seated position is less than the force effective to actuate said second closure to seated position so that, in the closing cycle of the valves, fluid can flow through said inlet port to said restricted outlet while said main-outlet port is closed.

4. A valve structure according to claim 3 and including means arranged so that, in the opening cycle of the valves, said first valve is partially opened before said second valve is opened.

5. In a valve structure: a casing having, for flow rough the casing, an inlet port, a main-outlet port, and a chamber interconnecting the ports; said casing having also a restricted outlet communicating with said chamber intermediate said ports; means on the casing forming a first valve seat around said main-outlet port and a second valve seat around said inlet port; a first and a second closure cooperable respectively with said first and said second seat to form therewith a first and a second valve; means mounting said closures for movement into and out of engagement with their seats to control flow through the respective ports; first resilient means biasing said first closure to seated position; second resilient means biasing said second closure to seated position; means movable gradually in response to variation of a controlling condition and capable, While said condition is varying in a given sense, of producing force for actuating the closures against the force of their bias, and, While the condition is varying in an opposite sense, of reducing said actuating force so that the closures can move under the force of their bias; and means for dividing said actuating force into two components and for applying one component to each of the closures concurrently, said force-applying means being yieldable so that the seating and unseating sequences of the closures are determined by the resultant of the forces then acting on the respective closures; the arrangement being such that, in the closing cycle of the valves, said first closure is seated before said second closure is seated so that fluid can then fiow through said inlet port to said restricted port.

6. A valve structure according to claim 5 and including means arranged so that, in the opening cycle of the valves, said first valve is partially opened before said second valve is opened.

7. A valve structure according to claim 5 wherein said second resilient means is of the two-way snap-acting type.

8. A valve structure according to claim 5 wherein said second resilient means comprises a resilient snap-spring constructed and arranged so that its force biasing the second closure toward seated position is substantially less than its force resisting movement of the second closure from seated to unseated position; and wherein the arrangement is such that, in the opening cycle of the valves, the resultant of the forces required to effect unseating of the second closure is greater than the resultant of the forces required to effect unseating of the first closure so that the first closure is unseated before the second closure is unseated.

9. A valve structure according to claim 8 wherein said first resilient means consists of two springs, one of said springs being arranged so that it is continuously effective, the other of said springs being arranged so that, in the opening cycle of the valves, it becomes effective only when the first closure is moved out of engagement with its seat through a small distance.

10. In a valve structure: a casing having, for flow through the casing, an inlet port and an outlet port arranged in spaced parallel relation; means on said casing forming a first valve seat around said main-outlet port and a second valve seat around said inlet port, said seats being generally coplanar and facing in the same direction; said casing having a chamber interconnecting said ports at their ends away from said seats; said casing having a restricted outlet communicating with said chamber; a first and a second closure cooperable respectively with said first and said second seat to form therewith a first and a second valve; means mounting said closures for movement in directions normal to said seats into and out of engagement therewith to control flow through the respective ports; first and second resilient means respectively biasing said first and said second closure to seated position; means movable gradually in response to variation of a controlling condition and capable, while said condition is varying in a given sense, of producing force for actuating the closures against the force of their bias, and, while the condition is varying in an opposite sense, of reducing said actuating force so that the closures can move under the force of their bias; a reciprocable member operatively connected to said force-producing means and mounted so that its axis of movement is between said ports and in a plane substantially parallel to the axes of movement of said closures; and means for distributing said actuating force to the closures,

' comprising an arm pivoted intermediate its ends on said member, and means operatively connecting the opposite ends of said arm with the individual closures; said forcedistributing means and said biasing means being arranged so that, in the closing cycle of the valves, said first closure is seated before said second closure is seated so that fluid can then flow through said inlet port to said restricted outlet.

11. A valve structure according to claim 10 and includ ing means arranged so that, in the opening cycle of the valves, said first valve is partially opened before said second valve is opened.

12. A valve structure according to claim 10 wherein said second resilient means comprises a resilient snapspring constructed and arranged so that its force biasing the second closure toward seated position is substantially less than its force resisting movement of the second closure from seated to unseated position; and wherein the arrangement is such that, in the opening cycle of the valves, the resultant of the forces required to effect unseating of the second closure is greater than the resultant of the forces required to effect unseating of the first closure so that the first closure is unseated before the second closure is unseated.

13. A valve structure according to claim 12 wherein said first resilient means consists of two springs, one of said springs being arranged so that it is continuously effective, the other of said springs being arranged so that, in the opening cycle of the valves, it becomes elfective only when the first closure is moved out of engagement with its seat through a small distance.

No references cited.

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