US2305915A - Control device and system - Google Patents

Description

Dec. 22, 1942. Q WANTZ 2,305,915

CONTROL DEVICE AND SYSTEM Filed March 22, 1940 2 Sheets-Sheet 1 Dec. 22, 1942. c;.'wAN1'z CONTROL DEVICE AND SYSTEM Filed March 22, 1940 2 Sheets-Sheet 2 when the armature Patented' 22, 1942 coN'rnor. nEvIcE AND SYSTEM Clarence Wantz,

Milwaukee, Wis.,

assignor to Milwaukee Gas Specialty Company, lwaukee, Wis., a corporation of Wisconsin Application March 22,1940, Serial No. 325,321

claims. (ci. 13a-139) This invention relates to improvements in control devices and, more particularly, an improved electromagnetic valve and to a thermoelectric safety shut-off system embodying such valve and operable to maintain a supply of fuel to a burner as long as a pilot light in juxtaposition is directed to i to the burner is burning and automatically to shut of! the fuel supply to the burner pilot light is extinguished.

In the illustrated embodiment when the of the invention,

the electromagnetic valve comprises an electromagnet, an armature, and a valve which is'closed is attracted to the electromagnet and is compelled to open position by retraction of the armature.

In the particular safety shut-0H system selected for illustration and embodying the improved form of electromagnetic valve, I provide a diaphragm or other equivalent supply pipe leading to the main burner, and by means of the improved electromagnetic valve I control the,application of pressure to the diaphragm in such manner that the diaphragm valve remains open'for the' supply of fuel to the burner as long as the pilot light is burning and is automatically closed to shut ofi ythe supply of fuel to the burner when the pilot light gnished.

The adaptability of the electromagnetic valve to remain closed when the armature is attracted and to be compelled to open position by retraction of the armature, and the adaptability of the ticular and advantageous correlation between the electromagnetic valve and the system.

The present invention also provides reset means for resetting the armature to attracted.

position, which reset means and the electromagnetic valve are adapted to remain closed to shut off the'flow of fuel through the valve part of the electromagnetic valve not only as long as the pilot light is burning, but also during the resetting operation.

Further features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying "drawings, in which:

Figure 1 is an elevational view of an electromagnetic valve em'bodying the present invention;

Figure 2 is an axial section through the elecvalve in the fuel tromagnetic valve and taken on the line 2-2 of y Figure 1; and

Figure 3 is a more or less schematic view showing a thermoelectric safety shut-off system ernbodying the present invention.

The control device selected for illustration and designated in its entirety at l0, comprises a valve body Il having an inlet l2 and an outlet I3.

A magnet mounting cup Il formed of lite or any other suitable or preferred insulating material is mounted upon the outer end of the valve body il and closes the outer end of the bore l5. The cup it has, at its inner end, an integral extension which fits into the counterbore I6, and the cup it is fastened in place by screws Il, pref-l erably with a washer i9 between valve body. t

The magnet housing is in the form of an out- 2E mountedupon the mounting cup lil, for example by pressed fit engagement of its open outer end in the mounting cup Ml, at 2l. magnet cup 2li is reduced at its inner end at 22, and the armature housing,

in the form of an outwardly opening metal cup 23, is mounted on the cup 2li, for example, by pressed fit engagementof its outer open end telescopically over the reduced inner end of the cup 20. The inner end of the cup 23 is preferably reduced, as shown.

The electromagnet comprises a generally U- shaped magnet frame 25 positioned within the cup 20, with its legs extending through openings in the inner end of the cup 20 and presenting pole ends within the armature cup 23. The form `of the magnet frame may be varied, and variations in the other .parts of the device are also contemplated Within the scope of the present invention. The particular magnet frame 25 selected for illustration has a threaded stud 26 integral therewith, or welded or otherwise joined thereto. This stud 26 extends into an opening or recess 21 in the vmounting cup I4, and has threaded engagement with a nut 28 for clamping the magnet frame 25 rigidly and, at the same time, removably in place. The nut 28 has a keri for engagement by a screw driver or other suitable tool, and a sealing washer 29 may be provided between the nut 28 and the inner end of the recess 21.

Fixed in the mounting cup i4 as, for example, by molding the insulating material of the cup thereto and extending endwise from the cup I4 are a pair of spaced metallic terminal connectors 33 and 3l having aligned openings and split cutwardly of these openings as shown at 32.

the cup and the.

' amature spring magnet coil u frame 25, and tend out into oblique ends connected surrounds the legs of the magnet the leads or ends of this coil exopenings 35 and have their to the terminals I and Il in a manner to have good conducting contact masnet frame and between the inner end of the cup 20 and the adjacent end of the The armature 40 inner end of the cup 23.

An amature stem head 46 is secured by a pin 50 is in the form oi a coiled spring interposed between the head 46 and the appear.

The disk 49 seats inwardly upon a shoulder inthe bore of the valve body, and the action of the spring 50 tends to compress the packing Il armature stem 42 to seal the interior of the armature cup from the gaseous or other fuel which passes through the valve body and to seal the valve body against the escape of fuel out around the magnet mounting cup Il. The deby the washer i8. Threaded at 56 With member 58, for example by the valve spring 62, is the valve member 64 shown as of disk-like form. The valve member 64 is provided with a leather washer or vother yielding valve seating member 65 for engagement with the valve seat 60.

The spring 62, which is of coiled form, is interposed between the valve member 64 and a spring disk 65. As long as the armature 40 is in attracted position, this spring 62 maintains the valve member 6B closed against the seat 66, thereby shutting oil! the iiow of fuel through the valve part of the electromagnetic control device. The spring disk 65 is slidable in the cooperating cylinder part of the valve housing in the resetting vice is further sealed against the escape of fuel cates through openings operation, and a reset wise secured on the outer end of the stem I2 is a valve stem head 14. When the is released upon deenergization oi the 4electromagnet, the spring il actuates 'the armature stem I2 and the armature Il carriedl thereby in- In its movement to v is held open as long as the amature is in retracted position.

For the plDOse of resetting the armature".v

to attracted positio the reset stem 'Il is mounted coaxial with the valve stem 12 and for reciprocatory movement in the inner endof the valve goes out.

In Figure 3 of the any suitable burner, such as 'I'he inlet chamber 94 |04 in the partition I with the interior of the inner diaphragm chamber |02 so as to subject the inner side oi' the the burner Il is other fuel thereto.

of the valve communil couple in any diaphragm to the pressure of the fuel 'in the fuel supply pipe 9|. The diaphragm 99 carries at the center thereof a valve stem |06 which has reciprocatory movement in the partition |00. A valve member |08, shown as of disk-like form, is carried by the inner end of the stem |06 and is adapted to seat upon the valve seat 91 to shut off the flow of fuel to the burner 90. The valve member |08 is shown in open position, allowing fuel to iiow through the pipe 9| to the burner 90, and the diaphragm is preferably provided with a suitable weight at |40 for actuating the valve |08 to closed position when pressure is applied to the outer diaphragm chamber |03 by the opening of the valve 64.

In juxtaposition to, or associated with, the main burner 90 is the usual or any suitable or preferred pilot burner indicated more or less dlagrammatically at ||0,whlch pilot burner is intended to remain lighted for the purpose of relighting the main burner. 'This pilot burner H0 is supplied with gaseous or other fuel by pipes and H2, the pipe I|| ming connected at ||3 to the main fuel supply pipe 9| anterior to the valve 92. The pipe is also connected at H to a pipe ||6 which leads to the inlet l2 of the electromagnetic control valve |0, and is suitablyI connected thereto. A pipe ||3 eads from the outlet |3 of the electromagnetic control valve l0 to the outer diaphragmchamber |03 for supplying fuel under pressure into this chamber when the electromagnetic control valve is open.

While any other suitable or preferred form of thermocouple and lead connection may be employed within lthe scope of the broader aspects of the present invention, the particular thermocouple and lead connection shown in the drawings are of the general character disclosed and claimed in Oscar J. Leiris Patent No. 2,126,564, granted August 9, 1938. The thermocouple designated in its entirety at |20 comprises an outer .tubular metallic thermocouple member |2| and an inner metallic thermocouple member |22 disposed within the outer thermocouple member and joined at one end to the end of the outer thermocouple member to form the thermal junction |23 which is placed in position to be heated by ,the pilot light as shown in Figure 3. An inner lead conductor |24 is joined to the inner thermocouple'member to form an internal thermal junctionv |25, and an outer tubular lead conthermocouple member, for example through a sleeve |21, to form a third thermal-junction |28. The outer lead conductor and outer thermocouple member enclose the inner lead conductor and inner thermocouple member. The inner lead conductor |24 is insulated from the outer lead conductor |26, for example, by a wrapping of insulation on the inner lead conductor.

The inner and Aouter lead conductors are preferably of a character that will permit bending as desired to permit disposing the thermodesired position. At the same time, the lead connection is preferably of a character to support V,the thermocouple in any desired position, although the thermocouple may have any other desired support such as, for example, on the nilot burner. At the opposite end, the inner lead conductor ,|24 extends from vthe outer lead conductor |26 and has a metallic terminal sleeve |30 fixed thereon in good conductive contact therewith and spaced from the end' of the outer lead conductor |26. An insulating sleeve |32 is interposed between the ternals 30 and 3|` Avalve by slipping couple lead means through the opening |34 in valve by loosening ductor |26 is connected to the outer tubular minal sleeve |30 and the adjacent end of the outer lead conductor |26.

The thermocouple is connected to the termiof the electromagnetic control the terminal end of the thermoone terminal 30 and into the opening |34 ln the other terminal, with the terminal sleeve |30v in the opening |34 in one terminal 3| and the end of the tubular thermocouple leadv |26 in the opening |34 in the other terminal 30. The screws |35 are then tightened to clamp the split portions 32 rof the terminals 30 and 3| into good conductive contact and gripping engagement with the terminal sleeve |30 and tubular lead |26, respectively. The thermocouple is disconnected from the electromagnetic control the screws |35 and withdrawing the terminal end of the thermocouple leads from the terminals 30 and 3|.

The operation is as follows:

When the pilot. light |0 is burning, the heat thereof on the thermal junction |23 produces a thermoelectric current in the coil 34. The magnet frame 25 and armature 40 are preferably formed of an alloy of relatively low magnetic reluctance, and, as a result, the relatively weak thermoelectric current produces a magnetic eld of suflicient strength so that when the armature 40 is placed in contact with the pole ends of the magnet frame by pushing the reset stem 10 inwardly, the magnetic attraction holds the armature in attracted position against the magnet.

If the pilot flame is extinguished, the holding action of the electromagnet ceases to be sufiicient to hold the armature 40 in attracted position, and the spring 50 moves the armature to retracted position. The armature stem 42 moves inwardly to retracted position with the movement of the armature, and its inner end or the armature stem head 46 thereon engages the end of the valve stem head 14 and actuates the valve 64 to open position. As already pointed out, the

spring 50 is sufliciently stronger than the spring v 62 to accomplish this result. Thus, movement of the armature 40 to retracted position moves the valve to open position, and this valve 64 is maintained open as long as the'armature is retracted. f

When it is desired to reset the device, the reset stem v1|) is pressed inwardly, and by engagement of its inner end with the end of the valve stem 12 the valve stem is moved inwardly through the valve member 64, moving' the valve stem head 14 into contact with the armature stem head 46 so that continued inward movement of the reset stem will move the armature to attracted position. rZihe valve 64 is adapted to remain closed during the resetting operation; also, as long as the pilot light is burning.

If the pilot burner is lighted and sets up a thermoelectric current to hold the armature in attracted position, the valve 64 will remain closed when the reset, stem is released. 1f, on the other hand, the pilot burner is not lighted to produce the thermoelectric current for holding the arma- `valve to closed position actuated to retracted position to open the valve 64 upon release of the reset stem.

When the valve 64 is opened upon extinguishment of the pilot burner, a supply of fuel is delivered through the pipes and ill into the valve chamber of the electromagnetic control device, through the valve opening 50 and pipe 8, into the outer diaphragm chamber |03. A bleed tube |24 is provided for bleeding the fuel from the outer diaphragm chamber |03, this bleed tube |24 being of smaller diameter, or otherwise restricted, to permit pressure to be built up within the outer diaphragm chamber |03 when the valve 64 ls open.

The building up of pressure in the outer dia-` v phragm chamber |08 by the opening of the valve 64 upon extinguishment 'of the pilot burner results in overcoming the pressure on the inner side of the diaphragm sulciently to actuate the of fuel to the main burner. 'I'his building up of pressure in the outer diaphragm chamber |03 may be only sufllcient to equalize the pressure on opposite sides of the diaphragm, and the valve |08 may be weighted to close, or provided with other means for closing, the same when that is accomplished. The bleed tube |24 provides pressure release means for relieving the pressure Ain the outer diaphragm chamber |03 when the valve 64 is closed. 'I'he bleed tube preferably deliversl the gas which is vented from the outer diaphragm chamber |03 into the furnace or adjacent the main burner or the, pilot burner, so that it may be consumed in the operation of the system. 'Ihe amount of gas or vented from the outer diaphragm chamber |03 through the tube |24 is relatively restricted, so that vthere will be no danger in the free escape thereof even with the main burner and the pilot the outer surface of the diaphragm 99, the discharge of fuel through the `bleed tube |24 is discontinued except to the extent necessary to vent the fuel in the chamber |03 and the connected pipes.

The showing of the fuel supply pipe 9| leading to the burner 90 is more or less diagrammatic, it being understood that may lbe provided with a shown) usually in proximity to the burner to which air is admitted in the usual way, as well understood in the art.

I do not intend to be limited to the precise details shown or described.

I claim:

1. Incombination, a net mounted on said valve body, an electromagvalve body, an armature for said electromagnet, a valve seat in said valve body, a valve member, means urging said valve member into closed position against said valve seat as long as said armature is in attracted position, a valve stem having reciprocatory move- .ment through said valve member and provided with a valve stem head presented toward said armature, and an armature stem carried by said armature and cooperable with said valve stem head for actuating said valve to open position by retraction of said armature. A

2. In combination, a. valve body, an electromagnet mounted on said valve body, an armature for said electromagnet, a valve seat in said valve body, a valve member, means urging said valve to shut ofi the supply fuel which is I this fuel supply pipe mixing cham-ber (not nation,

connected from therewith tor resetting said armature to attracted position.

a valve body, an electrosaid valve body, an armature for said electromagnet, means for sealing said electromasnet and said armature from the interior of the valve body. a valve seat in said valve body, a valve member, means urging said valve member into closed position against said valve seat as long as said armature is in attracted position, means for actuating said armature to 5. In a device, of the -class described, in combi- CE WANTZ.

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