US2299286A

US2299286A - Magnetic safety valve

Info

Publication number: US2299286A
Authority: US
Inventors: Wantz Clarence
Original assignee: Milwaukee Gas Specialty Co
Current assignee: Milwaukee Gas Specialty Co
Priority date: 1939-08-17
Filing date: 1939-08-17
Publication date: 1942-10-20
Anticipated expiration: 1959-10-20

Description

Oct.. 20, 1942. c. wANTz MAGNETIC SAFETY VALVE Filed Aug. 17. 1939 2 Sheets-Sheet l Get. 20, 1942. c. WANTz MAGNETIC SAFETY VALVE Filed Aug. l?, 1939 2 Sheets-Sheet 2 ma M 6 Patented Oct. 20, 1942 MAGNETIC SAFETY VALVE Clarence Wantz, Milwaukee, Wis., assignor to Milwaukee Gas Specialty Company, Wis., a corporation of Wisconsin Milwaukee,

'Application August 17, 1939, Serial No. 290,680

18l Claims.

This invention relates to safety devices for heating and other apparatus and has particular reference to an improved magnetic safety valve.

I t is common to employ for various safety shutoff purposes a valve or an electric switch which will remain in operative position only when some controlling condition is functioning as desired or has a desired value. A particularly useful purpose for such a valve or switch is in a safety pilot or "safety shut-off in a control system for heating apparatus and the like wherein the valve or switch will remain in operative position to maintain, for instance, the desired supply 'of fuel to the burner as long as, for example, the

flame to which the safety device is subjectedsuch as a pilot flame-is ignited; the valve or switch operating to safety position to shut oi the fuel supply tothe burner if the flame fails or is extinguished.

It has previously been proposed to provide a control system generally of the class described with a valve in the fuel supply line leading to the burner, there being an electromagnet and an armature for the electrom-agnet which, when attracted, holds the valve in open position, and

when retracted releases the valve for movement to closed position, and a thermocouple placed in position to be heated by the pilot burner, or other flame, and connected with the electromagnet so that the electromagnet will be energized to hold lthe armature in attracted position and thereby the valve open as long as the thermocouple is heated by the flame, the electromagnet being deenergized, or at least becoming insufficiently energized, to hold the valve open upon extinguishment of the flame.

It has also previously been proposed to provide a control lsystem generally of the class described with an electroresponsive valve in the fuel supply line leading to the burner, there being an electric circuit for this valve, a switch in said circuit, an electromagnet and an armature for the electromagnet which, when attracted, holds the switch closed, thereby maintaining the electroresponsive valve in open position, and a thermocouple placed in position to be heated by the pilot burner, or other flame, and connected with the electromagnet so that the armature will be held in attracted position and thereby the switch in closed position to maintain the valve open as long as the thermocouple is heated by the flame, the electromagnet being deenergized or at least becoming insufciently energized to hold the switch valve thereupon operating to closed position to shut oi the fuel supply to the burner.

According to the rst o1' the previously proposed schemes as above set forth, the relatively weak thermoelectric current produced by the heat of the flame on the thermocouple has been incapable of energizing the electromagnet sufficiently to actuate the valve to open position and, as a result, reset means has been required for resetting the amature to attracted position and the valve to open position.

According to the second of the previously proposed schemes as above set forth, it has been necessary to provide a switch in the circuit for the electroresponsive valve, to maintain this switch closed bythe electromagnet connected in circuit closed upon extinguishment of the flame and the with the thermocouple as long as the flame is ignited and to release said switch for movement to open position to open the circuit for the electroresponsive valve in the fuel supply line upon extinguishment of the flame.

One of the main objects of the present invention is to make it unnecessary to provide reset means for the purpose described and to eliminate the manual resetting operation heretofore required to reset the armature to attracted position and the valve to open position.

Another object of the invention is to make it unnecessary to provide in the circuit for the electroresponsive valve in the fuel supply line a switch under the control of the electromagnet connected in circuit with the thermocouple and to eliminate the matter of closing and maintaining said switch closed as long as the flame is burning and releasing same for movement to open position upon extinguishment of the flame.

Another object is to provide a safety system for fuel Iburners whereby the valve in the fuel line leading to the burner will not only be closed automatically Whenever the burner to which the safety system is subjected, as for instance the pilot burner, `is extinguished, but which will also -be opened automatically and without manual resetting to open position whenever the burner to which the safetyl system is subjected is ignited, and will be maintained open as long, for instance, as the pilot burner is burning.

Another and more specific object is to provide in a system of the class described a fuel supply line leading to the burner. a magnetic valve in said line, a rst electromagnet, an armature therefor, and means comprising a second electromagnet connected in circuit with the .thermocouple for holding the first electromagnet in position wherein the armature therefor is actuated 2 to attracted position to open the valve and hold vthe valve open as long as the flame is burning, the second electromagnet becoming deenergized or at least not sufciently energized to hold the first electromagnet in operative position upon extinguishment of the flame, whereupon the iirst electromagnet is released for movement with the armature therefor in its movement to retracted position to close the valve and shut oil the supply of fuel vto ,the burner.

It is also a more specic object of the present invention to provide the electromagnet, which is connected in circuit with the thermocouple, with an armature which is normally held in attracted position and returned to attracted position regardless of whether or not the electromagnet is energized by the heat of the name on the thermocouple, the force for holding this amature in attracted position being insuflicient to hold the other electromagnet in operative position unless 'Y the holding electromagnet is energized by the heat of the flame on the thermocouple.

Another object is to provide an improved short circuiting arrangement for deenergizing the main valve controlling electromagnet, orat least reducing the energization thereof sufficiently to release said electromagnet for movement to its operative position in which it is adapted to be held by the holding electromagnet, thereby freeing the holding electromagnet and the means for moving the armature thereof to attracted position, of the armature for the main electromagnet and also of the shut-oil valve and of the lspring or other means for actuating the shut-off valve to closed position. l

Another object of the present invention is to 4provide a magnetic vvalve of the class described which is of simple character vand relatively low cost. and which will operate positively and effectively for the purposes described.

Further objects and advantages of the invention will appear from the following detailed description taken in connection with the accompanying drawings, in which:

Figure 1 is a top plan view of a magnetic valve burner. The connection between the pilot tube and the fuel supply conduit I4 is preferably disposed anterior to the valve I5, or is otherwise arranged to supply fuel to the pilot burner I2 when the vvalve I5 is in closed position, shutting ofi. the supply of fuel to the main burner I0, as Well as when the valve I5 is open.

'Ihe magnetic valve I5 comprises a valve housing 20 having a fuel inlet 2l and a fuel outlet 22. The inlet 2I is tapped internally to receive the inlet pipe section I4 of the fuel supply pipe,

and the outlet 22 is threaded externally for connection at 23 to the outlet pipe section I 4a leading to the main burner I 0. In the illustrated embodiment of the invention, the outlet 22 is formed on a cover 24 which closes the open top of the housing 20 as the device is viewed in Figure 2, and is secured in place by cap screws 25, preferably with a gasket 26 between the valve housing and the cover as shown. Within one end of the housing 2U is an inlet chamber 28 closed 01T from the interior of the housing 20 by a wall 29 and adapted to have communication with the interior of the housing 20 and thereby with the outlet 22 through a tubular valve seat member 30 which has threaded engagement in an internally threaded' opening in the top of the enclosure for the inlet chamber 28.

'I'he valve seat member 30 has an integral guide support 32,*and fixed therein is a guide sleeve 33. The valve member 34 is of disc-like form and is secured at one end of a reciprocatory valve stem 35. 'Ihe valve stem 35 has reciprocatoryfmovement in the sleeve 33. The attachment of the valve member 34 to the stem 35 is preferably of generally universal character as shown at 36, or otherwise formed to permit self- 4 accommodation ofthe valve member to the valve embodying the present invention, with the cover for'the valvehousing removed and showing more or less diagrammatically the valve vembodied in one form of safety control system; and

Figure 2 is' a longitudinal section taken on the line 2--2 of Figure l.

Referring now to the drawings, which are for purposes of illustrating one embodiment4 ofl the Ainvention and oneparticlilarmanner of-using the same and are not to be construed `asl limitingthe scope of the invention, either as to the form of the magnetic valve or as to the illustratedruse of the same, the burner I0 is any suitable or preferred burner, such as the main burner of a hot water heater, gas furnace, oil heater, automatic space heater, gas range, or it may be a conversion burner or any other burner.

Associated with the main burner I0 is the usual or any suitable or preferred pilot burner indicated more or less diagrammatically at I2, which pilot burner is intended to remain lighted for the purpose of relighting the main burner upon extinguishment thereof. 'I'he pilot burner I2 is supplied with gaseous or any other suitable fuel, for example by a tube connected to the fuel supply conduit I 4 which supplies fuel to the main burner. The magnetic safety device of the riresent invention is shown in the form of a magnetic valve designated in its entirety at I5 and positioned in the fuel supply line leading to the main seat 38 at the adjacent end of member 30.

The particular valve member shown in the drawings )preferably` has 'a valve disc gasket or yielding seating material 40 secured thereto for yielding seating engagement with the valve seat 38. The gasket or yielding seating material 40 is shown clamped between a washer 42 and a flange 43 on the member 44 by a nut 45 which has Vthreaded engagement with a threaded stem integral with the member 44. These -details may, of course, vary Widely within the scope of Y the present invention. A'coiled spring 48,` interposed between' the rbase of the housing 20 as the v device is viewed in Figure -2,' or between any other relatively fixed abutment and the valve memberI 34, serves to actuate the yvalve member to closed position engaging'the seat 38 to shut off the supply of fuel to the main burnerfwhen, for example, the ame at the pilot burner is extinguished, as will hereinafter appear.

Also disposed within the valve housing 20 vis an electromagnet 50 comprising a magnet frame 5I shown as made up of U-shaped laminations, although this may vary within the broader aspectsr of the invention. The laminations are secured together at 52 and secured to the outer' sides of one leg of the magnet Pframe are a pair of bracket members 53 which extend upwardly and are pivoted upon a pin 54, thereby supporting the electromagnet 50 for pivotal or rocking movement. The pin or pivot 54 is carried by the outstanding arms of a U-shaped bracket 55, the .base of which is secured,

for instance, by screws 56 to the adjacent end wall of the valve housing 20.

The coil or winding 58 for the electromagnet the valve seat I8 is shown ascoiled about one of the legs of the magnet frame 8|, although this, too, may vary, and shading pole means is preferably provided, as indicated at 88, for a purpose well understood in the art. Strips 8| of insulating materlal extend down between the coil 88 4and the opposite sides of the leg of the magnet frame about which the coil is wound. .The opposite ends of these strips 8| are turned out along the opposite ends of the coil-88, and the upper outturned end is extended between the coil 88 and the shading pole means 88 ,as indicated at 82. A relatively light coiled spring 88 is interposed between the bottom oi' the magnet frame 8| and the bottom of the valve housing 28, preferably in position generally diagonally opposite the pivot I4 for maintaining the electromagnet in the desired position and cushioning its movement, as will hereinafterppear. The insulating strips` 82 serve to insulate from the magnet frame and the shading pole means I8 the metal `members 83 which extend through the opening in the coil and between the out-turned ends of which the coil is secured.'

The electromagnet 58 is provided with an ai; mature 88 shown as of laminated-construction and pivoted at one end upon the pivot 54 between the bracket members 82 of the magnet frame. Looseness is preferably provided at the pivotal support, as indicated at 88, to permit the arma-l ture properly to seat against the pole ends of the magnet frame when in attracted/position. The laminations forming the armature 85 are secured together at 88, and' the outer laminations form extending arms 88 at the outer end of the armature. A block` 18 is secured between the outer ends of .the arms 88, and threaded for adjustment in the block 18 is a screw 12, the inner end of which is of concaverform at 18 for engagement withthe adjacent end of the valve stem 85, which is preferably rounded for proper cooperation with the screw. The outer end of the screw 12 is provided with a kerf 14'which is adapted to be engaged by a screw driver or other suitable tool for the purpose of adjusting the screw in the block 18 to adjust the operation of the valve 34 by the movement of the armature 85.

A step-down transformer 88 supplies current for energizing the electromagnet 58. This transi former has a primary winding 8| connected to line wires 82, which may be the line wires of a though a room thermostat, pressure switch, or

arm 88 is bowed outwardly with its free end normally retained out of contact with the contact 82 by the inherent resiliency in the arm.

The contact arm Il and contact 82 form a short circuiting switch which is closed, for instance, by engaging the arm I8 with the finger and pressing the free end `of the arm into engagement with the contact 82. Any other suitable or preferred form of switch may be employed. The closing of this switch short circuits the coil oi' the electromagnet Il, closing the circuit 84,88 through the contact arm 88 and its cooperating contact 82 to deenergize the coil 88, or at least reduce the energization thereof sumciently to release the electromagnet I8 from the armature 88 for movement to the position shown in Figure 2, as will hereinafter appear.

'lhe circuit comprising the conductors 84 and 88 is preferably provided with an overload circuit breaker shown diagrammatically at 88 which acts to open this circuit to protect the same, and particularly the transformer 88, in case the contact arm 88 is held in engagement with the contact 82 too long. The circuit 84, 88 is also provided with a manually operable switch 88, a1-

other controls may be used in lieu of or with the switch 88 as indicated, for instance, at 88'.

For the purpose of holding the electromagnet 88 in the position shown in Figure 2 and against rocking or swinging movement about its pivot 54,

I provide holding means comprising a second 11o-volt circuit or any other suitable circuit.

I The secondary winding 83 is connected through conductors 84 and 85 with terminals on the valve housing 28. 'Ihese latter terminals comprise terminal screws 86 connected as shown diagrammatically in Figure l, in circuit with the respective conductors 84 and 85. Each screw 88 is threaded into a terminal bushing or sleeve 81 secured in the-wall of the valve housing 28, for

example as shown, or in any .other suitable.

with, the contact arm 83 and contact member 82 being insulated from the wall of the valve housing 28 by the insulation at 88. The contact electromagnet |88. This second or holding electromagnet comprises a magnet frame |8| shown of generally U-shaped form and provided with an armature |82.

The housing and. lead connection cap for the electromagnet. |88 are of the general character disclosed and claimed in the copending application of Clarence Wantz', Serial No. 239,790, flied November l0, 1938. The cap |84, which is preferably formed of Bakelite" or any other suitable or preferred insulating material, has an integral cylindrical extension which iits in a counterbore at the outer end of the bore in the hollow boss or tubular extension |08 on the valve housing 28. The cap |84 is fastened in place by cap screws |81 preferably with a sealing gasket or washer |88 between the cap and the end of the boss |88.

The electromagnet housing II8 is in the form of a generally cup-shaped meta-1 shell secured, for instance, to the cap |84 by pressed t engagement of its open end in the cap. The housing or shell I|8 is reduced at its inner end, and the armature housing II2, which is also in the form of a generally cup-shaped metal shell, is mounted on the shell II8, for instance by secure pressed ilt engagement of its open end telescopically over the reduced inner end of the shell |I8. The inner end of the shell II2 is preferably reduced as shown.

The magnet frame |8| is positioned Within the shell ||8 with its legs extending through openings in the inner end of the shell and presenting pole ends within the armature housing I i2. Fixed rigidly in the cap |84, as, for example, by molding the insulating material of the cap thereto and extending endwise from the cap, are a pair of spaced metallic terminal connectors I|4 and |I5 having aligned openings H6 and split outwardly of these openings at I I8. The electromagnet coil |28 surrounds the legs of the magnet frame |8I, and the leads or ends of this coil extend out and are connected to the terminal concap |04 and in a manner to providegood conducting contact. The coil |20 is preferably covered with insulation between its bared ends at I 2 I, Suitable'insulation is provided at |22 between the inner-end lof the coil and the inner end of the shell ||0, and, if desired, additional insulation may be provided between the turns of the coil and the'legs of the magnet frame,|0|.

The armature' |02 is disposed inthe armature 2,299,286 nectors 4 and I I5 preferably externally of the,`

outer thermocouple member, constitutes an enclosure about the inner thermocouple member and the inner lead conductor and the innerI thermocouple Junction |56. The inner lead conductor |55 .is insulated from the outer lead conductor |51r by'a wrapping of insulation on the inner lead conductor as indicated at |62.

housing I2 and is adapted to be held in attracted position against thefpole ends of the magnet frame |0| upon energization of-'the'electromagnet |00. The armature 02 is of disc-like form and is secured to the outer end of a reciprocatory stem |25. stem 25 may, if desired, be suiciently loose to permit self-accommodation of the armature to the pole ends of the magnet frame, although this is not necessary because the connection between The inner and outer lead conductors |55 and |51 are preferably of a character that will permit bending, as desired, to permit disposing the thermocouple in any desired position. At the same time the lead connection may be of a The attachment of the armature to the.

. from the outer lead conductor |51 and has a the rinner end "of the stem andthe electromagnet 50 is of a character to permit this selfaccommodationof the armature tothe magnet frame |0|.

The stem or shaft |25 extends inwardly for reciprocating movement through an opening in the inner end of the housing ||2. Packing |20 of felt or other suitable or preferred material is interposed between the innerend of the shell ||2 and a disc |29,which disc seats inwardly upon the shoulder |30. The inner end of the pin or extending laterally from the opposite sides thereof. The bracket members or side pieces 53 on opposite sides of the adjacent leg of the magnet' frame 5| have integral notched lugs forming hooks |34 which engage over the pin |32 on opposite sides of the block as shown in Figure 2. The engagement of the hooks |34 with the pin |32 connects the electromagnet 50 to the armature. stem or shaft |25, so thatwhen the electromagnet |00 is energized to hold the armature |02 in attracted position, the electromagnet 50 will character to support the thermocouple in any desired position, although supporting brackets or other means may be employed for supporting the thermocouple and lead connection. At the end opposite the end at which the thermocouple is positioned th innerV lead conductor |55 Vextends metallic terminal sleeve |64 xed thereonin good conductive contact therewith and spaced from the end of the outer lead conductor. An insulating sleeve |65 is interposed between the terminal sleeve |66 and the outer lead conductor |51.

. shaft |25 carries a block 3| which has a pin |32 be held tlxedly in the ,position shown in Figure 2.

The armature |02 is normally maintained in attracted position and returned to attracted position by a spring |40 coiled about the stem or vshaft |25 and interposed between thte armature |02 and the inner end of the armature housing preferably formed of an alloy of low magnetic" lar metallic thermocouple member |5| and an inner metallic thermocouple member |52 disposed within the outer thermocouple member vand joined at one end to the outer thermocouple member to form the thermal junction |53 which is placed in position to be heated by the llamefor instance, the pilot ilame |54. An inner lead conductor |55 is joined tothe inner thermocouple member to form an internal thermal junction |56, and an outer tubular lead conductor |51 is connected to the outer thermocouple member through a sleeve |58 to form a third thermal junction |59. The outer lead conductor |51 encloses the innerlead conductor and, with the 'magnet 50.

A quick detachable connection is thus provided between the thermocouple leads andthe terminals ||4 'and |I5`ior the electromagnet coil |20. The thermocouple is connected to 'the terminals ||4 and 5 by slipping the terminal end of the thermocouple lead means through the opening ||6 in one terminal ||4 and into the opening ||6 in theother terminal, with the terminal sleeve |64 in the opening 6 in one terminal ||5 and the end of the tubular thermocouple lead |51 in the opening ||0 in the other terminal ||4. Screws |58 are then tightened to clamp the split portions ||0 of the terminals ||4 and ||5 into good conductive contact and gripping engagement with the terminal sleeve I 64 and tubular lead |51, respectively; The thermocouple-is dis-v connected from the device by loosening the screws |53 and withdrawing the terminal end of the thermocouple leads from the and ||5.

Assuming that the parts of themagnetic switch. 2, the operationY are positioned as shown in Figure of the device is as follows:

When the pilot flame |54 or other flame, to the heat of which the thermocouple is subjected, is burning, the heat of this llame upon the thermal Junction |53 produces a thermoelectric current in the con m of the holding electromagnet inn. 'I'he magnet frame |0| and armature |02 are reluctance and, as a result, the. thermoelectric current produces a magnetic field of sumcient strength to hold the armature 02 in attracted position against 'the pole ends of the magnet frame. 4The spring |40, which normally holds the armature |02 in attracted position,'assists the magnetic action ,in holding this armature against the magnet frame when the electromagnet |00 is` energized and, as a result, the electromagnet 50 is held iixedly in the position shown through the pin and hook connection |32, |34.

Closing of the manual switch 36 with the short circuiting switch arm 33 open completes the circuit 04, 35 through the coil 56 of the electro- 'I'his produces a relatively strong magnetic ileld in the elctromagnet 50, and, as ares/ult, with the electromagnet 50 held in the .position shown in Figure 2, the armature 55 is swung by the magnetic action about its pivot 54 'to attracted position against the pole `ends o! .the magnet frame 5|. This movement of the vterminals |4 .tromagnet 50 positioned as shown. Manual or other control valves may, of course, be provided in the fuel supply line leading to the burner i0. With the valve 34 thus held-in open position, the magnetic attraction of the armature |02 to the electromagnet |00, aided by the spring |40, is suilicient to hold the electromagnet 50 positioned as shown against the action of the spring 1 4l. The magnetic attraction of the armature 65 to the electromagnet 50 is also suillcient to hold the armature 35 from moving away from the electroma'gnet 50 to retracted position under the action of the spring 48.

If the flame, to the heat of -which the thermocouple |50 is subjected, is extinguished, the holding action of the electromagnet ceases to be suilicient to hold the amature |02 in attracted position, and the hold on the electromagnet 50 is thus released. The electromagnet 50 is thereby freed for movement with the armature 65, and the spring 48 moves the valve 34 to closed position, shutting oi the supply of fuel to the burner i0 at the same time, through the valve stem 35, swinging the amature 65 to its retracted position about the pivot 54 with the electromagnet 50 following the movement of the armature.

The device is reset merely by relighting the pilot burner I2 and closing the short circuiting switch 83 for an instant. Th'e switch 93 does not have to be held closed until the heat of a name on the thermocouple has set up the th'ermoelectric.

inl-,5

ture, or other foreign matter-for instance, dur--I ing shipmentand until the device is installed-for v use-the outlet 22 is tapped internally at |88 to If the pilot burner i2 is lighted and sets up a I thermoelectric current to hold the armature |02 in attracted position and thereby the electromagnet 50 positioned as sho'wn, the magnetic eld set up in the electromagnet 50 by the flow of current through the coil thereof draws the armature 65 to attracted position against the pole ends of `the magnet frame 5|. This actuation of the armature to attracted position moves the valve 34- to open position through the stern 35, and the valve is held open as long as the name |54 is burning andthe circuit 84, 85 is completed.

If the burner is not lighted to produce the thermoelectric current for holding the armature |02 in attracted position and thereby the electromagnet 50 in operative position, the valve 34 will t be closed and the armature 65 and electromagnet 50 swung to the retracted position of the armature 55 under the action oi the spring 48, as already described. The circuit 84, 85 is opened and closed as desired by means of the switch 96.

For the purpose of sealing the interior of the valve housing 20 against the entry of dust, mois- .receive a suitable closure plug (not shown) which may be removed when the device is ready for use. The inlet 2l may also be closed during shipment land until the device is ready for use by a suitable seal fastened over th'e outer end of the tubular boss or extension through which the inlet 2| enters the housing 2l. or arranged otherwise as desired.

'I'h'e plug |85 (Figure l) closes an opening in the side wall vof the valve housing 20. 'I'his opening is aligned axially with the pivot pin 54 and permits insertion and withdrawal of the pin therethrough.

The spring 53, which is preferably a weak and.-

low rate spring. takes out any lost motion in the connection |3I, |34 between the armature stem |25 and the magnet frame 5I. 'I'he valve 34 is always preferably in a vertical position. Th'e spring |40 is preferably just strong enough to hold the armature against the magnet frame |0| and to hold the magnet frame 5l against the spring 63. The spring 48 is strong enough to raise the armature 65 and to hold the valve 34 closed against the seat 38. The spring |48 is weaker than the spring 48 but spring |40 plus the pull of the armature |02 to the magnet frame |0I when the electromagnet comprising th'e magnet frame |0| is energized is stronger than the spring 48.

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

I claim:

1. In combination, an electromagnet comprising a pivoted magnet frame having a magnet coil thereon, a pivoted armature for said electromagnet. a second electromagnet, and an armature for said second electromagnet which', when held attracted by -energization of said second electromagnet. is adapted to hold said ilrst electromagnet against pivotal movement.

2. In combination, an electromagnet comprising a pivoted magnet frame having a magnet coil thereon, a pivoted armature for said electromagnet, a second electromagnet, and an armature for said second electromagnet which, when held attracted by energization of said second electromagnet, is adapted to hold said rst electromagnet against pivotal movement, said iirst electro'- magnet being freed for pivotal movement with' said amature upon deenergization of said second electromagnet.

3. In combination,V an electromagnet comprising a pivoted magnet frame having pole means and provided with a magnet coil, a pivoted armature for said electromagnet, a second electromagnet, an armature for said second electromagnet, and means connecting the magnet frame of said rst electromagnet with the armature of said second electromagnet.

4. In combination, an electromagnet comprising a 'pivoted magnet frame having pole means and provided with a magnet coil, a pivoted armature for said electromagnet, a second electromagnet, an armature for said second electromagnet, and means connecting the magnet frame of said rst electromagnet with th'e armature of said second electromagnet, said connection being of a character `to allow pivotal movement of said irst electromagnet and there being lo'oseness in the pivot for said armature to permit accommodation of said armature to the pole means of dsaid first electromagnet.

5. In combination, an'electromag'net comprising a pivoted magnet frame -having a magnet coil, a pivoted armature forsaid electromagnet,

a second electromagnet, an armature for said second electromagnet, `means connecting lthe magnet frame of said rst electromagnet with the armature for said second electromagnet, and shading pole means for said rst electromagnet.

6. In combination; valve means comprising a in circuit with said thermocouple, an armature for said electromagnet, means normally holding said armature in attracted position and `returning said armature to attracted position: regardless of whether or not the electromagnet is energized by the heat of the name on the thermocouple, and a second electromagnet adapted to be held in operative position by said first electromagnet as long as said flame is burning, the force of the means for holding said armature in attracted' position being insuiiicient tb hold said second electromagnet in operative position unless the holding electromagnt is energized bythe heat of the flame Von the thermocouple.

8. In combination;J a f uel supply line, avalve in said line, a movable electromagnet having an operative position'and adapted when in said position and when energized to move said valve to open position, and a second electromagnet which, when energized, is electromagnetically connected to said rst electromagnet to hold same in operative position and, when deenergized, releases the electromagnetic connection with said first electromagnet for movement of said electromagnet to inoperative position and said valve to closed position.

9. In combination, a fuel supply line, a valve in said line, a movable electromagnet having an operative position and adapted when in said position and when energized to move said valve to Cil energized, to release said first open position, a'fsecond electromagnet which,

when energized, is electromagnetically connected to said first electromagnet t hold same in' operative position and, when deenergized, releases the electromagnetic connection with Vsaid iirst electromagnet for movement of said first electromagnet to inoperative position and movement of said valve to closed position, and

means for deenergizing said first electromagnet..

tion.

10. In combination, a fuel supply line, a valve in said line, an electromagnet having an operative position and adapted, when in said position and when energized, to move said valve to open position, asecond electromagnet which, when energized, is electromagnetically conto free same for movement to operative posinected to said iirst electromagnet to hold same in operative position and, when deenergized, releases the electromagnetic connection with said first electromagnet for movement of said valve to closed position, a thermocouple placed in posif ing an operating position and a safety position,v

electromagnet which,

tion to be heated by a name and connected in circuit with said second eiectromagnet, anda circuit.provided vwith a source of current and forvmovement to safety position.

12. In combination, a controlling member havingan operating position and a safety position, a iirst electromagnet, means comprising a second electromagnet which, when energizec'is adapted to hold said first electromagnet vin a position wherein it is operative to move vsaid controlling member to one of said positions, said second electromagnet being adapted, when deelectromagnet/for movement to inoperative position for movement of said controlling member to the other position, a thermocouple placed in position to be heated by a flame and connected in circuit with said second electromagnet, and a circuit provided with a source of current and connected to said first electromagnet. A

13. In combination, a controlling member having an operating position and a safety position, a first electromagnet, an armature for said irst electromagndt which, when attracted-,to said electromagnet, is adapted to actuate said controlling member to operating. position and to hold same in said position, means comprising a second electromagnet which; when energized, is adapted -to hold said iirst electromagnet in a position wherein it'is operative to move said armature to attracted position and to hold same in attracted position,`said second electromagnet being adapted, when deenergized, to release said first electromagnet for movement to inoperative position to release said controlling member for movement tothe other position, a thermocouple placed in position to lbe heated by a iiame and connected in circuit with said second electromagnet, and a circuit provided with a source of current and connected to said first electromagnet.

14. In combination, a controlling member hava nrst electromagnet, an armature for said first when attracted to said electromagnet, is adapted to actuate said ccntrolling member to operating position and to hold same in said position, means comprising a second electromagnet which, when energized, is adapted to hold said first electromagnet in a position wherein it is operative to move said armature to attracted position and to hold same in attracted position, said second electromagnet being adapted, when deenergized, to release said rst electrcmagnet for movement to inoperative position to release said controlling member for movement to the other position, a thermocouple placed in position to be heated by a name and connected'in circuit with said second electromagnet, a circuit provided with a source of current and connected to said first electromagnet, and means for deenergizing said rst releasable to release said electromagnet to free same from said amature for movement to the position in which it is held by said second electromagnet.

15. In combination, a controlling member having an operating position and a safety position, a first electromagnet, an armature for said first electromagnet which, when attracted to said electromagnet, is adapted to actuate said controlling member to operating position and to hold same in said position, means comprising a second electromagnet which, when energized, is adapted to hold said iirst electromagnet in a position wherein it is operative to move said armature to attracted position and to hold same in attracted position, said second electromagnet being adapted, when deenergized, to release said rst electromagnet forV movement to inoperative position to release said controlling member for movement to the other position, a thermocouple placed in position to be heated by a flame and connected in circuit with said second electromagnet, a circuit provided with a source of current and connected to said iirst electromagnet, and means for deenergizing said first electromagnet to free same from saidarmature for movement to the position in which it is held by said second electromagnet, said last means comprising a short circuiting switch in the circuit connected to said rst electromagnet.

16. In combination, a controlling member` having an operating position and a safety position, a iirst electromagnet, an armature for said rst electromagnet which, when attracted to said electromagnet, is adapted to actuate said controlling member to operating position and to hold same in said position, means comprising a second electromagnet which, when energized, is adapted to hold said first electromagnet in a position wherein it is operative to move said armature to attracted position and to hold same in attracted position, said second electromagnet being adapted, when deenergized, to release said first electromagnet for movement to inoperative position to release said controlling member for movement to the other position, a thermocouple placed in position to be heated by a ame and connected in circuit with said second electromagnet, a circuit provided with a source of current and connected to said rst electromagnet, means for deenergizing said first electromagnet to free same from said armature for movement to the position in which it is held by said second electromagnet, said last means comprising a short circuiting switch in the circuit connected to said rlrst electromagnet, and an overload circuit breaker in said last mentioned circuit.

17. In combination, a valve housing having an inlet chamber adapted for communication with the interior of said housing, said housing having an outlet leading therefrom, an electromagnet pivoted in said housing, a circuit provided with a source of current and connected to said electromagnet, an armature pivoted in said housing, a second electromagnet adapted for holding said first electromagnet in operative position whereinHV it is operative to move said armature to attracted position, said valve being actuated to open position by movement of said armature to attracted position and held in open position as long as said armature is held in attracted position and said iirst electromagnet is held in operative position, said `second electromagnet being adapted, when deenergized, to release said rst electromagnet for movement to inoperative position to release said valve for movement to closedposition, means in the circuit for said first electromagnet for deenergizing said first electromagnet to free same from said armature for movement to the position in which it is held by said second electromagnet, and a thermocouple placed in position to be heated by a flame and connected in circuit with said second electromagnet.

18. In combination, an electromagnet compris ing a movable magnet frame having pole means and provided with a magnet coil, an armature for said electromagnet, a second electromagnet, an armature for said second electromagnet, and means for connecting the magnet frame of said rst electromagnet with the armature of said second electromagnet, said connecting means being operable when the armature for said second electromagnet is held in attracted position to hold the magnet frame of said rst electromagnet against movement.

CLARENCE WANTZ.