US2688446A

US2688446A - Heat responsive valve

Info

Publication number: US2688446A
Application number: US151193A
Authority: US
Inventors: Robert A Wittmann
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-01-17
Filing date: 1950-03-22
Publication date: 1954-09-07
Anticipated expiration: 1971-09-07

Description

R. A. wrrTMMlNl HEAT RESPONSIVE VALVE Original Filed Jan. 17, 1947 Sqn. 7, 1954 2 Sheets-Sheet 1 4 wm n f.

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ywwwmyw Patented Sept. 7, 1954 UNITED STATES PATENT OFFICE HEAT RESPONSIVE VALVE Robert A. Wittmann, Chicago, Ill.

2 Claims.

l My invention relates, generally, to valve structures and, more particularly, to heat responsive valves.

While the valve of my invention may be Widely used, it is well suited for use in a gas burning system such as that illustrated and described in my copending application, Serial No. 722,584, led January 17, 1947, of which this application is a division.

`It is an object of this invention to provide a valve which is automatically opened or closed in response to differences in temperatures to which the heat responsive means of the valve is subjected. The heat responsive means can be of any desired type, such as ci-metallic strips; bulb and bellows, either liquid or gas lled; thermo-couple energized solenoid; electric solenoid, etc.

In the preferred form of the invention, the means responsive to differences in temperature by which the valve is actuated relies upon the magnetic character of Curie point metals, namely, metals and alloys which normally are ferromagnetic, but which when heated suilciently, lose their magnetic properties. The transition temperature, or Curie point, as it is called, at which the change in magnetic characteristics occurs on heating is a distinct property of each metal or alloy and varies widely among the various metals and alloys. Each metal or alloy, however, has its own distinct and non-varying Curie point. A valve member moved in response to the attraction between a magnet and a Curie point metal may, therefore, be manipulated by heating the Curie point metal above its Curie point. The invention will be illustrated in connection with this form of heat responsive means, but it will be readily appreciated that other forms may be employed.

It is a further object of my invention to provide` means whereby a Curie point metal, or other heat responsive element employed in the heat responsive valve of my invention may be cooled rapidly below its Curie point so that the valve member responsive to such element (for example, responsive to the attractive force between the Curie point Ametal and any other magnetic member) may be operated quickly. 1n the accomplishment of this object, I provide, for example, a valve in which the Curie point metal is positioned directly in the ilow of gas which passes through the valve when the valve member is opened. A very definite snap action of the valve is obtained by using such a Curie point metal and permanent magnet. Such metals retain their temperature responsive characteristics indefinitely.

It is another object of my invention to provide a double acting valve mechanism which provides flow through alternate outlets, the actuation of the valve being governed by heat responsive means. Such valve mechanism opens one outlet as it closes the other, and vice versa. The heat responsive means may be any of those mentioned above.

Itis a further object of the invention to provide a simplified valve structure employing Curie point metal and a permanent magnet for operating the movable valve element.

Further objects, uses and advantages of the invention will become apparent, or be obvious, from the following description, when taken in connection with the accompanying drawings, in which:

Figure 1 illustrates the valve of my invention employed in conjunction with a gas burning system such as that illustrated and described in my copending application, Serial No. 722,584;

Figure 2 illustrates a modified form of the automatic heat responsive valve of Figure 1; and

Figure 3 illustrates a double acting valve mechanism of my invention with another form of heat responsive means for actuating the movable valve member.

Turning iirst to Figure 1, the automatic heat responsive valve is indicated generally by the reference numeral 34. The gas burning system illustrated in Figure 1 does not need to be described extensively here, since a full description thereof may be had in my copending application referred to above, namely, Serial No. 722,584, led January 17, 1947. Sulice it to say here that the main gas supply pipe l0 communicates by a conduit 32 with the inlet chamber 36 of the valve 34. The outlet chamber 45 of the valve 34 communicates with, by means of a conduit 5D, a manually controlled valve 42 and a conduit 53 to a gas burner 5S, for which the valve of my invention is adapted to provide a control. In one form of the invention there may also communicate with the inlet chamber 36 of the valve 34 a conduit 40 which is adapted to communicate with a pilot light 62 through the manually controlled valve 42 and conduit 60. It will be understood, however, that the Valve does not need to include the conduit 40 in its operation, but that such inclusion provides a modified structure.

The inlet chamber 35 of valve 34 is separated from the outlet chamber 45 by

walls

48 and 48a, a passageway l2 being formed in the former wall and having a valve seat 73 at one end, the passageway and seat together sometimes being referred to as a port. The passageway 12 may be closed by a movable valve member 14. Where the conduit 48 is employed, it may be closed by a movable valve member 16. Both members 14 and 16 may be xedly secured on the same rod 18 which is guided by passageway 8|) in the wall 48a. A spring 82 is interposed between the wall section 48a and the valve member 14, thus assisting gravity to urge the valve members 14 and 16 downwardly (as viewed in Figure 1, where the valve mechanism has been turned into the horizontal plane in order to provide a sectional View which is more illustrative of the structure). The movable valve member 14 is urged by the spring and by gravity away from its valve seat 13 and the valve member 16 is simultaneously urged toward its seat 38.

The heat responsive means for actuating the movable valve members will now be described. This heat responsive means is exemplified by the use of C'urie point metal, but other heat responsive means such as bi-metallic strips; `bulb and bellows, either liquid or gas filled; thermocouple energized solenoid; electric solenoid, etc. may be employed. One such other form will be described hereinafter. At the .upper end of the rod 18 is xed a permanent magnet 84 which is attracted toward a piece of ferromagnetic Curie point metal 66 when said metal 86 is at a temperature below its Curie point. This Curie point metal 86 is supported by a heat conducting member 38 having apertures 83 around the metal 86. The member 88 extends out of the housing of the valve 34 from between the casing 96 and the lid 92 into the vicinity of a pilot which may be the oven burner pilot 68. When the pilot 68 is lit from a source of gas, heat is transferred through the conducting member 88 to the Curie point metal 86 which, because of such heating, loses its magnetic qualities and fails to exert an attractive force on the permanent ymagnet 84 when a temperature above its Curie point is reached. Thereupon, the spring 82, together with the force of gravity, forces the valve `members 14 and 16 downwardly, as viewed in Figure l. member 14 being unseated and in the valve member 16 being seated upon the seat 38.

At this time, there is a means of communication between the inlet chamber 36 of the automatic valve 34 and. its outletchamber 46, namely,

passageway 12, and gas under pressure will, therefore, ow from conduit 32 and thegas supply .line IIJ into chamber 36. From chamber 36 the gas will go through the passageway 12 and be directed by

wall sections

48 and 48a all about the Curie point metal 86 which is directly in the path of .flow of gas to the outlet chamber 46 and the conduit 50, with resulting cooling action on said Curie point metal. When the oven burner pilot 68 is lit, any ilow of gas past the Curie point metal 86 will fail to bring said metal below its Curie point, once it is heated above that point. However, continued flow of gas past the metal, after the pilot 68 and any other source of heat affecting the conducting member 88 have been extinguished, will assist in cooling the Curie point metal 86 and the heat conducting strip 88, so that the Curie point metal 86 will more quickly reach a temperature below its Curie point and thus regain its magnetic qualities for purposes of attracting the magnet 84 and thus closing the passageway 12 to prevent .further ilow of gas through the automatic valve to the outlet chamber 46 and thence from the chamber 46 to the conduit 5|).

This results in the valve When the movable valve member 14 is seated upon the seat 13 by reason of the magnet 84 being attracted to the Curie point metal 86, when the latter has cooled below its Curie point, movable valve member 16 will be lifted from its valve seat 38, thereby permitting communication between the inlet chamber 36 of valve 34 and the conduit 46. The continued flow of gas through the valve 34 and about the Curie point metal 86 when the valve is open and the pilot .68, or other heating means, has just gone out, will very quickly reduce the temperature of the Curie point metal below its Curie point with a resulting quick closing of the valve by movable Valve member 14.

A modiiication of the automatic heat responsive valve 34 of Figure 1 is shown in Figure 2. wherein it is indicated generally by the reference numeral |34. The only substantial diiTerence between the valve |34 and the valve 34 of Figure 1 is in the Curie point metal-element |86 which serves both as a ferromagnetic member and also as a heat transmitting member, comparable to member 88 of Figure l. The entire element |86, therefore, is a Curie point metal element which serves as its own conducting member and its outermost end A|81 is subjected to the flame of a pilot, such as the oven burner pilot 68, or other heating means. A depressed portion |89 `of the element |86 serves as the magnetic element directly above the permanent magnet V84.

It will also be observed that the element |86 forms the closure member for the top of the valve |34 and therefore eliminates the need of a lid, such as lid 92 of the valve 34 in Figure V1. By combining three functions as it does, the element |86 makes the valve .|34 less expensive than the valve 34. In the structure of Figure 2, the flow of gas through the valvecan be directed by the

wall structures

48 and 48a against one side of the sheet of Curie point metal instead of all about it, asmay be done .in the case of valve 34 of Figure 1. However, since the .element |86serves as the closure of rthe valve |34, the top surface thereof is .largely exposed to air which is able to carry awayheat. Consequently, the rapid cooling of the Curie point element |86 after the pilot light 68 is extinguished permits the Curie point element rapidly to cool below its Curie point so that it will regain its magnetic properties and thereby attract the magnet 84 and cause 'the movable valve member '14 to seat upon the valve v13 and to vlift the movable valve 16 from its seat 38.

In Figure Y3, there will'be seen a valve mechanism 234 having the Vsame inlet 32 and outlets 46 and 56 as those shown with respect to Figures 1 and 2. The double valve mechanismcomprising the movable valve elements -14 and 16 -on operating rod 18, ywith -their vrespective seats 13 and'38, and also the

inner walls

48 and 48a, are similar to `those previously described above with respect 'to Figures 1 and 2. The lheat vresponsive operating means of Figure 3 'for the movable valve members 114 and 16 comprises a bellows 284 connected with the common operating rod 18 for the movable valve members 14 yand 16, which bellows is `filled either with liquid or gas, and is connected in pressure-tight relationship to the upper wall 283 of the valve mechanism 234. By means of an apertured screw 'fitting 285, the interior of the bellows communicates, through a hollow tube 286 with abulb 281, which is adapted to be .positioned above the .-ame of `a pilot, such as the oven burner pilot 68 of a gas burning system shown in Figure 1. The bellows is flexible and resilient and its resiliency urges valve member 14 to its seat when the pressure within the bellows is below a certain level. At such time the bellows overcomes the tendency of spring 82 to move the valve members 14 and 1B in the opposite direction. When the pilot 68 is lit, it heats the liquid or gas in the bulb 281, and the heated gas or liquid expands and, through the resilient bellows 28e, moves the operating rod 18, which is connected with the bellows, downwardly so that gas or other fluid may ilow from inlet 32 through the passageway 12 of valve mechanism 234 and be directed by the wall means 48 and 48a, around the bellows 234 and out of the outlet 50. The passage of iluid or liquid past the bellows does not cause the gas therein to be sufficiently cooled to cause the bellows to contract until such time as the llame at the pilot burner 88 is extinguished. But when the flame at pilot burner 68 is extinguished, a iiow of gas or other iluid past the bellows 284 will then act to cool the bellows and the expansible material in it, so that such material will contract and the resilient bellows will also contract and draw the valve member 14 upwardly against its seat. In that fashion the valve member 14 is quickly actuated to closed position after the ame of the pilot burner 88 is extinguished. It will be seen that when the valve member 14 is unseated, the valve member 16 is seated, and vice versa.

While I have illustrated two forms of heat responsive means for manipulating the movable valve members, it will be appreciated that other known forms of heat responsive means could also be employed.

Although I have described preferred embodiments of my invention, it will be apparent that modifications may be made therein without departing from the scope of the invention, and I do not intend to be limited thereto except insofar as the appended claims are so limited.

I claim:

1. A heat responsive valve for controlling luid :flow comprising a housing having an inlet port and an outlet port, wall means in said housing including a rst portion between said inlet and outlet ports having a valve port located therein, a second portion spaced from said iirst portion and said valve port and a third portion connecting said first and second portions and eX- tending between said valve port and said outlet port, a valve cooperating with said valve port for controlling iuid ow therethrough, said valve Abeing guided for movement with respect to said valve port by said second portion of said wall means, a second outlet port in said housing located between said inlet port and said valve port, a second valve provided to cooperate with said second outlet port for controlling flow therethrough, the arrangement being such that, when said iirst named valve is positioned to preclude fluid iiow through said valve port said second valve is positioned to allow iiuid iiow through said second outlet, a heat responsive Curie point metal element, said rst named valve including a permanent magnet member which cooperates with said Curie point element to position said rst named valve to preclude fluid iiow through said valve port when said Curie point element is cooled below its Curie point, at least a portion of said heat responsive Curie point element being disposed in said housing between said second portion of said wall means and said outlet port and being adapted for actuating said valve, said second and third portions of said wall means cooperating with said first portion to define a channel for directing passage of fluid between said valve port and said portion of said Curie point element, said portion of said `Curie point element being positioned directly in the path of fluid passing through said channel and being adapted to be heated from a source of heat outside of said housing to position said first mentioned valve for passage of fluid from said inlet port, through said valve port and said channel, against said portion of said heat responsive means and thence to said outlet, the arrangement being such that, when said Curie point element ceases to be heated by the outside source, the uid cools said Curie point element whereupon said first mentioned valve is positioned by said Curie point element to preclude iluid ow through said valve port.

2. The heat responsive valve set forth in claim 1 wherein the Curie point metal element is directly heated by the source of heat outside said housing and a depressed portion of said element is positioned directly above said permanent magnet.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,311,809 Giesler July 29, 1919 1,403,493 Furber Jan. 17, 1922 1,842,333 Te Pas Jan. 19, 1932 1,957,276 Leonard May 1, 1934 2,183,104 Preston Dec. 12, 1934 2,185,422 Prutton Jan. 2, 1940 2,233,659 Wittmann Mar. 4, 1941 2,299,155 Lange Oct. 20, 1942 2,390,985 Boyer Dec. 18, 1945 2,556,479 McGrath June 12, 1951