US3591138A

US3591138A - Heat motor safety valve construction and parts therefor

Info

Publication number: US3591138A
Application number: US871097A
Authority: US
Inventors: Denis G Wolfe
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1969-12-29
Filing date: 1969-12-29
Publication date: 1971-07-06
Anticipated expiration: 1988-07-06

Abstract

This disclosure relates to a heat-motor-operated valve means which is only adapted to open the valve means when the heat motor is actuated and a condition-responsive means is sensing a certain flame at a pilot burner means that will ignite fuel passing through the subsequently opened valve means to a main burner means, the valve member of the valve means being carried on one end of a bimetallic lever means that carries the heat motor thereon and against which the condition-responsive means is engageable when sensing the certain flame.

Description

United States Patent Denis G. Wolfe [72] Inventor GreensburgJa. [2|] Appl. No. 871,097 [22] Filed Dec.29, 1969 Division of Ser. No. 688,922, Dec. 7,1967, Pat. N6. 3,498,730. I [45] Patented July6, 1971 [73] Assignee Robertshaw Controls Company Richmond, Va.

[54] HEAT MOTOR SAFETY VALVE CONSTRUCTION AND PARTS THEREFOR 6 Claims, 10 Drawing Figs.

52 u.s.c1. 251 333,

251/ ll [51-] lnt.Cl F16k 25/00 50 Field ofsflrch 251/331, 333

[56] References Cited UNITED STATES PATENTS 961 ,045 H 1910 l lulse 2 5lj l 3,229,956 1/1966 White 3,394,732 7/1968 Lisciani 251 333x FOREIGN PATENTS 8,225 1956 Germany 251/333 Primary Examiner-Amold' Rosenthal An0rneys-.lackson Auzville, .lr., Robert L. Marben and Candor, Candor and Tassone means being carried on one end of a bimetallic lever means,

that carries the heat motor thereon andagainst which the condition-responsive means is engageable when sensing the certain flame.

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' SHEET 1 or 5 FIG.2

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FIG.6

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HIS ATTORNEYS sum u 0F 5 PATENTED JUL 6 I97! INVENTOR DENIS G. WOLFE M,MFZJW HIS ATTORNEYS PATENTEUJUL 619?: 3,591,138

SHEET 5 OF 5 INVENTOR DENIS G. WOLFE 4% him HIS ATTORNEYS HEAT MOTOR SAFETY VALVE CONSTRUCTION AND PARTS THEREFOR This application is a divisional patent application of its copending parent application, Ser. No. 688,922, filed Dec. 7, 1967, and is assigned to the same assignee to whom the parent application is assigned.

This invention relates to a heat-motor-operated safety valve construction as well as to improved parts for such a valve construction or the like.

It is well known that many fuel-burning appliances are provided with electrically operated valve constructions for interconnecting a fuel supply manifold to the main burner means and will be opened only when a thermostatic means sends an electric signal to the valve construction to provide heat input for the cooking apparatus or the like and will terminate the supply of electrical current to the valve construction to close the same when the temperature effect reaches or exceeds a selected temperature effect.

However, in such prior known electrically operated safety valve constructions, some means must be provided for preventing the operation of the electrically operated fuel supply valve means if the ignition system for igniting the fuel issuing from the main burner means is inoperative for any reason.

Accordingly, one of the features of this invention is to provide an improved safety means for an electrically operated fuel supply valve construction wherein the valve construction cannot be opened unless the valve construction senses a predetermined condition, such as the sensing of the pilot burner flame that is utilized for igniting the fuel subsequently passing through the electrically operated valve construction to the main burner.

Accordingly, it is an object of this invention to provide an improved electrically operated fuel supply valve having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide improved parts for such a valve construction or the like.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying ,drawings forming a part thereof and wherein:

FIG. 1 is a top view illustrating the improved valve construction of this invention as well as the pilot burner means utilized in combination therewith.

FIG. 2 is a cross-sectional view taken substantially on line 2-2 of FIG. 1, FIG. 2 illustrating the valve construction in its closed position.

FIG. 3 is a view similar to FIG. 2 and illustrates the valve construction in its opened condition.

FIG. 4 is a view similar to FIG. 2 and illustrates the valve construction in its closed condition even though the heat motor thereof has been energized and the condition responsive means thereof is not sensing a pilot flame.

FIG. 5 is a cross-sectional view taken substantially on line 5-5 of FIG. 2 with the valve seat member removed.

FIG. 6 is a cross-sectional view taken on line 6-6 of FIG. 5.

FIG. 7 is an exploded perspective view of various parts of the valve construction of this invention.

FIG. 8 is an enlarged, fragmentary, cross-sectional view illustrating the improved valve seat and valve member being in an opened position.

FIG. 9 is a view similar to FIG. 8 and illustrates the valve member initially engaging against the valve seat.

FIG. 10 is a view similar to FIG. 9 and illustrates the valve member fully closing the valve seat.

While the various features of this invention are hereinafter described and illustrated as being particularly adaptable for controlling the fuel supply of burner means for a cooking apparatus or the like, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide control means for other devices as desired. I

Therefore, this invention is not to be limited to only the embodiment illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGS. I and 2, the improved valve construction of this invention is generally illustrated by the reference numeral 20 and comprises a housing means 21 having an inlet 22 for supplying fuel from a fuel supply manifold (not shown) into an interior chamber 23 of the housing means 21 that leads to an outlet means 24A of the housing means 21 through a valve seat member 24, the outlet means 24A leading to a main burner means (not shown) disposed closely adjacent a pilot burner means 25 normally being supplied fuel in a continuous manner by a conduit means 26 interconnected to the fuel supply manifold.

A bimetallic lever means 27 is disposed within the chamber 23 of the housing means 21 and has one end means 28 secured to the housing means 21 and the other end means 29 free to move in the housing means 21 and carrying a valve member 30 for opening and closing a passage 31 passing through the valve seat member 24 and leading to the outlet means 24A.

The bimetallic lever means 27 carries a heat motor 32 that is secured thereto by spring clips 33, the heat motor 33 comprising an electrical heater having terminal means 34 and 35 respectively interconnected to

external terminals

36 and 37 carried by the housing means 21 and adapted to be interconnected to a thermostat or the like that will supply electrical current to the heat motor 32 to energize the same when the thermostat senses a temperature effect requiring that the main burner means be supplied fuel by the valve means 20 and that will terminate such electrical current when the thermostat senses that the heat input of the burner means should be terminated.

The lever means 27 includes an L-shaped part 38 adapted to be engaged by a ball 39 carried on the end of a stud 40 interconnected to the movable wall 41 of an expandible and contractable power element 42 secured to the housing means 21 in any suitable manner. The internal chamber of the power element 42 is interconnected to a capillary tube 43 that leads to a bulb 44, FIG. 1, disposed in such a position relative to the pilot burner means 25, that when a flame exists at the pilot burner means 25, such flame is sensed by the bulb 44 and causes the fluid therein to expand in such a manner that the movable wall 41 of the power element 42 is moved downwardly in the drawings to carry the lever means 27 therewith so that an intermediate part 45 of the lever means 27 will abut against an adjustable abutment means 46 of the housing 21.

As illustrated in the drawings, the adjustable abutment means 46 comprises a threaded adjusting screw disposed in a threaded bore 47 of the housing means 21 for a purpose hereinafter described.

When the bulb 44 senses that no flame exists at the pilot burner means 25, the fluid therein contracts in such a manner that the movable wall 41 of the power element 42 is moved upwardly in the drawings to the position illustrated in FIG. 4 whereby it can be seen that the ball end 39 thereof is not engaging the lever means 27 so that the same will not hold the intermediate part 45 thereof against the adjustable stop or abutment means 46 for a purpose hereinafter described.

The valve member 30 carried by the movable end 29 of the lever means 27 is best illustrated in FIGS. 7-10 and includes a cup-shaped rigid backing member 48 having an open end 49 surrounded by an annular surface means 50 provided with a substantially inverted V-shaped cross-sectional configuration with the closed end being defined by a substantially circular flat wall 51. The rigid backing member 48 is secured to the movable end 29 of the lever means 27 by a spider member 52 having the central portion 53 secured to the end 29 of the lever means 27 by rivetlike fastening means 54 whereby the plurality of fingers 55 of the spider member 52 can have the outer ends 56 thereof snap fittingly receiving radially outwardly directed tongues 57 on the rigid backing member 48 in suitable slot means 68 thereof. In this manner, the rigid and is held thereto by an annular retainer 59 held on top of the flexible membrane 58 at the outer periphery thereof by bent over tab means 60 of the rigid backing member 48.

Thus, it can readily be seen in FIG. 8 that when the valve member 30 is disposed away from the valve seat 24, the flexible membrane 58 is substantially flat across the open end 49 of the cup-shaped backing member 48 and is held in such flat condition by the natural resiliency of the flexible diaphragm or membrane 58.

The valve seat member 24 is soconstructed and arranged that the valve seat surface 61 thereof is annular and is arcuate in cross section so that the substantially 90 part of the surface 61 immediately adjacent the passage 31 passing therethrough will be first engaged by the flexible diaphragm 58 of the valve member 30 when the same initially closes against the seat 24 as illustrated in FIG. 9, such initial point of substantially annular line contact being defined by the reference numeral 62 in FIG. 9.

While the initial seating of the flexible membrane or diaphragm 58 of the valve member 30 against the valve seat member 24 as illustrated in FIG. 9 substantially seals off the passage means 31 from the fuel-receiving chamber 23 of the housing means 21, further upward movement of the movable end 29 of the lever means 27 is effected in a menner hereinafter set forth to cause the flexible diaphragm 58 to progressively wrap against the valve seat surface 61 in an outward radial direction as illustrated'in FIG. 10 whiledistorting the flexible diaphragm 58 into the open end 49 of the cupshaped rigid backing member 48 against the closed wall 51 thereof. In this manner, any chips, dirt or the like being located on the valve seat surface 61, membrane 58 or both to tend to prevent the closing of the passage means 31 by the valve member will be completely enveloped by the flexible compressed nature of the flexible diaphragm 58 of the valve member 30 against the valve seat surface 61 to insure a positive sealing of the valve seat member 24 so that when the valve member 30 is disposed in its fully closed position illustrated in FIG. 10, not only is positive sealing effected at the point 62 immediately adjacent the passage means 31 in the manner previously described, but also the annular ridge of the rigid backing member 48 substantially compresses the flexible diaphragm 58 between the same and the outer annular part 63 of the valve seat surface 61 to insure the sealing effect of the diaphragm 58 against the valve seat member 24.

Accordingly, the flexible membrane 58 when disposed in its fully closed position against the valve seat member 24 substantially seals against a relatively wide annular valve seat surface 61 from the point 62 in FIG. 10 to the point 63 in FIG. 10 completely around the passage means 31 to fully seal closed the same even though dirt or the like might be disposed on the valve seat surface 61, membrane 58 or both which will be fully enveloped by the flexible membrane 58.

Thus, it can be seen that the improved valve means member 30 and valve seat member 24 of this invention permit a full sealing-closed thereof when the valve member 30 is moved to its closed position.

Conversely, when the valve member is moved from its fully closed position illustrated in FIG. 10 toward its open position, the valve member 30 is moved downwardly from the position illustrated in FIG. 10 to the position illustrated in FIG. 9 before any opening of the passage means 31 of the valve seat member 24 to the fuel chamber 23 can take place whereby moving inertia is built up into the valve member 30 before the same opens the valve seat 24 so that a rapid opening thereof will take place in substantially a snap manner to insure that a sufficientquantity of fuel will be supplied to the main burner means for full ignition thereof each time the valve member 30 is cracked open.

The operation of the valve construction 20 will now be described.

Under normal conditions, the pilot burner means 25 is being continuously supplied fuel from the conduit means 26 and has been previously ignited so that the continuously burning pilot means 25 comprises a continuously burning standby ignition flame means for the main burner means even though the thermostatic device for the cooking apparatus or the like is disposed in its off position so that the thermostatic device will never supply electrical current to the heater means 32 of the valve construction 20 until the thermostatic device is turned to an on position thereof. However, with the pilot burner means 25 having the continuously burning pilot flame, such flame is sensed by the bulb 44 so that the movable wall 41 of the power element 42 is in its expanded downward condition as illustrated in FIG. 2 to hold the intermediate part 45 of the lever means 27 against the abutment or stop means 46.

If the downward expansion of the power element 42 should exceed the condition illustrated in FIG. 2, the L-shaped lever part 38 will be further moved downwardly in an overshoot manner by a mere bending at the point 64 so that undue pressure will not be placed on the lever means 27 during an overshoot condition of the power element 42. a

In addition, the lever means 27 and L-shaped part 38 thereof are so constructed and arranged that the same will compensate for ambient temperature changes in a conventional manner and need not be further described whereby when the heater means 32 is not energized, the natural condition of the lever means 27 is to compress the valve member 30 against the valve seat 24 in the manner illustrated in FIG. 10 and maintain that sealed condition regardless of whether or not the bulb 44 is sensing a pilot flame.

However, with the valve construction 20 normally disposed in the position illustrated in FIG. 2 and the thermostatic device is turned to a selected on position thereof so that the thermostatic device of the cooking apparatus initially determines that fuel should be supplied to the main burner means because the thermostatic device is sensing a temperature effect below the selected temperature effect, the thermostatic device will supply electrical current to the heater means 32 whereby the electrical heater means 32 will heat the bimetallic lever means 27 and cause the same to warp or bend between the engaged abutment or stop means 46 and the end means 29 thereof in the manner illustrated in FIG. 3 to open the valve seat member 24 and permit fuelto flow from the fuel chamber means 23 and out of the outlet means 24 A to the main burner means to be ignited by the pilot burner flame at the pilot burner means 25.

Thus, electrical energy is supplied to the heater means 32 of the valve construction 20 as long as the thermostatic device determines that a heat input is required.

When the thermostat device senses that the heat input being supplied by the main burner means has now reached or slightly exceeded the selected temperature effect, the electrical current to the heater 32 of the lever means 27 is terminated by the thermostatic device whereby the subsequently cooling lever means 27 begins to straighten out to the condition illustrated in FIG. 2 to close the valve seat 24 in the manner previously described in connection with FIGS. 8-10 so that the supply of fuel to the main burner means is terminated until the thermostatic device again determines that heat input is required. In this manner, the valve construction 20 is cycled between its opened and closed positions to maintain the selected temperature effect of the main burner means.

However, if no pilot flame is existing at the pilot burner means 25, the movable wall 41 of the power element 42 is disposed in the up condition as illustrated in FIG. 4 so as not to hold the intermediate part 45 of the lever means 27 against the abutment or stop means 46 of the housing means 21. Under these conditions, should the thermostatic device direct an electrical current to the heater means 32 to tend to open the valve seat member in the manner previously described, the heated bimetallic member 27 will now bend or warp between the opposed ends 28 and 29 thereof in the manner illustrated 'in FIG. 4 so that such bending of the bimetallic member 27 will not permit the valve member 30 to open away from the valve seat 24 as illustrated in FIG. 4.

Therefore, it can be seen that it requires two conditions to be present for the valve construction before the valve construction 20 can pass fuel therethrough, namely, not only must the heat motor means 52 for the bimetallic lever means 27 be energized to cause warping'or bending thereof, but also the condition-responsive means 42 must be sensing a predetermined condition in order to engage the lever means 27 and hold the-intermediate part 45 thereof against the stop means or abutment means 46 to permit the warping and bending of the lever means 27 to act in the manner to fully open the valve seat member 24. Thus, merely the sensing of the certain condition by the power element 42 will not by itself open the valve construction 20 and the mere energizing of the heat motor 32 by itself will not cause opening of the valve construction 20.

Accordingly, it can be seen that not only does this invention provide an improved valve construction having improved safety features, but also this invention provides improved parts for such a valve construction or the like.

While the form of the invention now preferred has been disclosed as required by the statutes, other forms may be used, all comingwithin the scope of the claims which follow.

- What I claim is:

1. In combination, a housing means having an inlet and an outlet separated by a valve seat, and a movable valve member carried by said housing means for opening and closing said 'valve seat, said valve member having a substantially cupshaped rigid backing member provided with an open end and a closed wall, said rigid backing member having said open end thereof covered by a flexible membrane that will engage against said valve seat and distort into said open end of said backing member to seal closed said valve seat, rigid backing member and said valve seat including means for compressing between said backing member and valve seat the flexible membrane at two annular areas thereof that are substantially concentric and that are spaced apart by another annular area thereof that is not compressed between said rigid backing member and said valve seat whereby said valve member is adapted to seal around said valve seat at least at said two annular areas of said flexible membrane.

2. A combination as set forth in claim 1 wherein said valve seat has an annular surface surrounding an opening passing therethrough, said surface being arcuate in transverse cross section so that said flexible membrane will initially engage said arcuate surface adjacent said opening with one of said two annular areas thereof and will, thereafter, progressively engage said surface'in a direction outwardly from said opening as said valve member is being moved to its fully closed position.

3. A combination as set forth in claim 1 wherein one of said two annular areas of said flexible membrane is compressed between said valve seat and said closed wall of said cupshaped rigid backing member when said valve member closes said valve seat.-

4. A combination as set forth in claim 1 wherein one of said two annular areas of said flexible membrane is compressed between said open end of said cup-shaped backing member and said valve seat when said valve member fully closes said valve seat.

5. A combination as set forth in claim 1 wherein one of said two annular areas of said flexible membrane is adapted to be compressed between said valve seat and said closed wall of said cup-shaped rigid backing member and the other of said two annular areas is adapted to be compressed between said valve seat and said open end of said rigid backing member.

6. A combination as set forth in claim 5 wherein said valve seat has an annular surface surrounding an opening passing therethrough, said surface being arcuate in transverse cross section so that said flexible membrane is adapted to initially engage said arcuate surface ad acent said opening with said

Claims

1. In combination, a housing means having an inlet and an outlet separated by a valve seat, and a movable valve member carried by said housing means for opening and closing said valve seat, said valve member having a substantially cup-shaped rigid backing member provided with an open end and a closed wall, said rigid backing member having said open end thereof covered by a flexible membrane that will engage against said valve seat and distort into said open end of said backing member to seal closed said valve seat, rigid backing member and said valve seat including means for compressing between said backing member and valve seat the flexible membrane at two annular areas thereof that are substantially concentric and that are spaced apart by another annular area Thereof that is not compressed between said rigid backing member and said valve seat whereby said valve member is adapted to seal around said valve seat at least at said two annular areas of said flexible membrane.

2. A combination as set forth in claim 1 wherein said valve seat has an annular surface surrounding an opening passing therethrough, said surface being arcuate in transverse cross section so that said flexible membrane will initially engage said arcuate surface adjacent said opening with one of said two annular areas thereof and will, thereafter, progressively engage said surface in a direction outwardly from said opening as said valve member is being moved to its fully closed position.

3. A combination as set forth in claim 1 wherein one of said two annular areas of said flexible membrane is compressed between said valve seat and said closed wall of said cup-shaped rigid backing member when said valve member closes said valve seat.

6. A combination as set forth in claim 5 wherein said valve seat has an annular surface surrounding an opening passing therethrough, said surface being arcuate in transverse cross section so that said flexible membrane is adapted to initially engage said arcuate surface adjacent said opening with said one of said two annular areas thereof and is adapted to thereafter progressively engage said surface in a direction outwardly from said opening as said valve member is being moved to its fully closed position until said other of said two annular areas is compressed between said valve seat surface and said open end of said rigid backing member.