US3157222A - Thermoelectrically operated semi-automatic flame control device for two or more burners - Google Patents

Description

Nov. 17, 1964 R. HASSA 3,157,222

THERMOELECTRICALLY OPERATED SEMI-AUTOMATIC FLAME CONTROL DEVICE FOR TWO OR MORE BURNERS Filed April 9, 1962 4 Sheets-Sheet l INVENTOR:

BY M, m.vww

Nov. 17, 1964 HASSA 3,157,222

THERMOELECTRICALLY OPERATED SEMI-AUTOMATIC FLAME CONTROL. DEVICE FOR TWO OR MORE BURNERS Filed April 9, 1962 4 Sheets-Sheet 2 Fig. 2

- 20' s /ZO INVENTOR: 12M \h BY M, MW a Vex-MW,

R. HASSA 3,157,222

CONTROL DEVICE FOR-TWO OR MORE BURNERS 4 Sheets-Sheet 5 IN V EN TOR.

Nov. 17, 1964 THERMOELECTRICALLY OPERATED SEMI-AUTOMATIC FLAME Filed April 9, 1962 Nov. 17, 1964 R. HASSA 3,1

. THERMOELECTRICALLY OPERATED SEMI-AUTOMATIC FLAME CONTROL DEVICE FOR TWO OR MORE BURNERS Filed April 9, 1962 4 Sheets-Sheet 4 IN V EN TOR:

United States Patent THERMOELEUIRIQALLY ()PERATED SEMI-AUTG- MATHC FLAME CONTRQL DEVICE FOR TWQ 0R MGRE BURNERS Richard Hassa, (lsnabruclr, Germany, assignor to G.

Kroinsclirorler Alrtiengesellschaft, Osnahruclr, Germany Filed Apr. 9, 1962, Ser. No. 186,132 Claims priority, application Austria, Apr. 8, T961, 2,841/61; Feb. 28, 1962, 1,663/62 12 Claims. (Cl. 158-131) This invention relates to a thermoelectrically operated semi-automatic flame control device for two or more burners each having a thermocouple associated with it.

Known devices of this kind for four or live burners comprise four or five small valve assemblies of a kind suited only to domestic appliances of small output.

Contrary to this, the device according to the invention has only one valve assembly and is equally suited to small and to large (industrial) apparatus with two or more burners.

The invention consists in having associated with each thermocouple an electromagnet, the electromagnets being arranged in a series adjacent to one another and on all of them being energized they cohere into a pile which holds open the shut-off valve of the device against a predetermined force, whereas an interruption of energy to even one of the electromagnets leads to the release of the pile, so that the disengaged portion of the pile causes the device to shut off the gas supply.

In a further embodiment of the invention, the outer electromagnet of the pile-the one remote from the valveis attached to a fixed support, and a guide of non magnetic material is aifixed on this support and projects inwardly axially into the electromagnets. This arrangement dispenses with control devices involving an external current supply and so is not subject to the diillculties which can occur with such current (as failure of line current). The pilot flames must, however, always'be ignited by hand.

In a further embodiment of the invention, the electromagnets, each energized by a thermoelectric current and in axial alignment with their respective armatures at pre determined spacing and loaded for example by a spring for closing the valve, are slidably movable, except for the armature of the inner electromagnet-nearest the valvewhich armature is rigidly attached to the vertical valve stem and for the armature of the outer electromagnet farthest from the valve-which armature is associated with a fixed support, such as the top of the housing encasing the electromagnets.

in order to control the burner used with the device, a further feature of the invention resides in that the armature of the outer electromagnet is slidably arranged in axial alignment in its support and has associated with it a switch controlling the burner gas valve. With the valve operated by external line current, it is also possible to provide automatic ignition in known manner and to switch on the ignition device after lighting and energization of the magnets by thermoelectric current.

The invention is described by way of examplein which the flame control device may or may not be combined with a burner gas valve.

In the accompanying drawings,

FIG. 1 is a cross-sectional view of one embodiment of the invention with the gas valve closed;

FIGS. 2, 3 and 4 are cross-sectional views of another embodiment of the invention, FIG. 2 showing the device with pilot burner valve closed, FIG. 3 showing the device in manually opened position for ignition of the pilot burners, and HG. 4 including a schematic illustration of the burners and associated apparatus in normal operating position; and

ice

FIG. 5 is a cross-sectional view of another form of the device with associated burners and circuitry shown schematically.

FIG. 1 of the drawings shows a valve body or casing 1 with gas inlet connection 2, gas outlet connection 3 to which is to be connected a pipe (not shown) to the everal pilot burners, and a further gas outlet connection 3a to which is to be connected a pipe (not shown) to each of the main burners. Between inlet connection 2 and outlet connection 3 is a passage including gas inlet chamber d'and gas outlet chamber 5 connected by an opening or gasway 7. Gasway or opening 7 is in partition or wall 6 dividing chambers 4 and 5. A gas passageway or duct leads from gasway 7 to pilot gas connection 3. On the partition 6 about gasway 7 seat two valve plates or closures 11 and 50. Valve plate 5t in gas outlet housing 5 is journalled on a push rod lit, which serves as a starting means operable by hand on a press knob 9 upwards against a return spring 8. This valve plate 50 is loaded by spring 51 on the inside of housing 1 to seat against the partition 6. The return spring 8 is however stronger than spring 51, so that the valve plate 565 is held away from the partition 6 when at rest by the stop 52 on the end of push rod or plunger 1%). The other valve plate 11 in the gas inlet chamber 4 and its rigidly attached stemor rod 12 closes the gasway 7 under the operation of resilient means formed by spring 13. The gas inlet chamber 4 and gas outlet chamber 5 are sealed at valve stem 12 and push rod it by O-rings 14, as also is the valve plate 54) where the push rod 18 passes through it.

0n the end of the actuating rod or valve stem 12 projecting from the valve casing 1 is rigidly fixed a disc 15 which forms the armature to the electromagnet 15 facing the valve casing 1. Above this electromagnet 16 are axially aligned further 'electrornagnets 17, T8, of which the outer electromagnet 18farthest from the valveis attached to a fixed support which may be cover Ztl which is attached to the tubular casing 19 enclosing the whole assembly of electromagnets 16, 17, 18. The support 20 is rigidly attached (through 19) to the valve casing l. All

the elcctrornagnets are preferably similar. Attached to the support Ztt is a stationary guide rod titiof non-magnetic material projecting axially into all the electromagnets. On this guide rod 643 slide all the electromagnets 16, 17, with the exception of 18. At 25 are shown the in sulated leads which pass through cover 2% to electromagnets iii, 17, 18, the leads 26 from them being grounded. The base of each electromagnet lti, l7, 18, is thickened and in 16, 17, serves as armature to the next outer one. The top electromagnet T8 is secured to the support 2% by screws into its thickened base.

In the drawing, for the sake of clarity, a gap has been shown between the electromagnets, but in ,fact by their own weight 16 and 17 lie close together and rest on armature 15. In this position it shuts and keeps shut the gasway 7 through the actuating rod or valve stem 12 and rigidly attached valve plate 11, further assisted by spring 13. At rest in this position of the valve, the gas inlet housing 4 is completely sealed and no gas can pass to main or pilot burners.

Each individual electromagnet 16, l7, 18 is electrically connected by a lead 25 and ground 26 to a thermocouple (not shown in FIG. 1) at the pilot flame to each main burner. The thermoelectric current produced at each thermocouple in the presence of the 'pilot flame energizes its respective electromagnet. The strength of spring 13 closing gasway 7 is such that it cannot close the gasway so long as all the electromagnets 16, 17, 18 are energized, when the electromagnets 16 andl7 together with the armature 15 adhere to electromagnet 18 which is attached to support 20.

To bring the device according to the invention from the position of rest shown in FIG. 1 to the ignition setting, the press knob 9 and with it the push rod 10 is pressed in against spring 8 far enough for the push rod 10 with its stop 52 to lifit the valve plate 11 from its seating, and to raise the armature 15 on which are electromagnets 16, 17 sufficiently to close the air gap between them and electromagnet 1S and form a complete pile. Pressing in the press knob 9 and with it the push rod 10 releases the valve plate and under pressure of spring 51 closes the gasway 7. Gas entering by the raised valve plate 11 from gas inlet housing 4 to gasway 7 can at first not enter gas outlet housing 5 but goes by the bypass duct to gas outlet connection 3 and is lighted for example by hand. The thermocouple at each pilot flame then generate current which through leads 25 and 26 energizes their respective eleotromagnets 16, 17, 18. The electromagnets so energized remain adhering to one another in the raised position and the pile constituted by the former pressing in of press knob 9 and push rod 14) is maintained by the now effective magnetic fields. Press knob 9 can then be released.

On the release of press knob 9, and because the return spring 8 is as already mentioned stronger than spring 51, the valve plate 50 is drawn back by the stop 52 of the returning push rod and against the weaker spring 51 and is lifted from its seat. Gas can pass through the now opened gasway into the gas outlet chamber 5 and thence by gas outlet connection 3a to the main burners, where the pilot flames are alight. The installation and with it the flame control device is then in the operating position.

If for any reason even one of the pilot flames is extinguished or the current from any thermocouple fails, the corresponding electromagnet and/or the armature 15 with its fixed valve stem 12 drops at once. The valve plate 11, aided by the spring 13, then immediately shuts the gasway 7. Thereupon further supply of gas to both main burners and all pilot burners is cut oil? at once, whereby all flames are extinguished, all thermoelectric currents cease, and so all electromagnets return to their position of rest.

The arrangement shown in FIG. 1 of the drawings by way of example is for at most three protected burners. To protect more burners, more movable electnornagnets must be placed on to guide rod 60.

In FIGS. 2, 3 and 4 there is on the valve stem 12 projecting from the casing 1 a disc 15 rigidly attached to the stem, serving as armature 15 to its adjacent magnet 16 here shown as a double magnet. The double magnet and the axially aligned top magnets 17 and 18 and armature 21 associated with magnet 18 are slidable on valve stem 12 in axial alignment. Armature 21 is itself slidably journalled in the fixed support and has a main gas valve switch operator 22., Theoperator 22 and the armature rigidly attached to it are loaded by a spring 23 between it and support 20, serving to bias the operator 22 outwards. In the outer position of the operator, contacts 24 of the main valve switch are opened and are closed in its inner position. The bases of the top magnets 17, 18 are thickened and serve also as armatures to the next inner magnets. Magnets 16, 17, 18 are shown for clarity as having a gap between each, but in fact by their own weight they lie close together and rest on armature 15. Inthis' position it shuts and keeps shut the gasway 7 through valve stem 12 and rigidly attached valve plate 11, further assisted by spring 13, while the armature 21 has opened the contacts 24 under the operation of spring 23 on its operator 22 and keeps them in this open position. Under pressure of spring 23, armature 21 rests against the support 20, soproviding one predetermined spacing of the valve stroke between the magnet 18 and armature 21. The spring 13 for closing the gas way 7 is of such strength that itcannot be shut so long as the magnets are energized and they then ad- 4. here to armature 21, supported by spring 23. The spring 23 is weaker than spring 13, but always strong enough to be able to draw outwards the initially loaded magnets in the event of any failure of thermoelectric current and so to open the contacts 24.

In order to bring the device according to the invention from the position of rest shown in FIG. 2 to the ignition setting, the press knob 9 and with it the push rod 10 is pressed in against spring 8 far enough to lift the valve plate 11 and so open the gasway 7, until the armature 15 presses up the magnets 16, 17, 18 lying on it to the armature 21. Gas passing through the opened gasway 7 from inlet gas chamber 4 to gas outlet chamber 5 flows then to the pilot burners shown in FIG. 4 and must there be lighted by hand. The thermocouples arranged at each pilot flame (see FIG. 4) then generate current which fiows through leads 25 to each magnet and through leads 26 to ground. The electromagnets so energized remain adhering to one another. Press knob 9 can then. be released.

The magnets 16, 17, 18 with the armature 15 and 21 now take up the position shown in FIG. 4. In this position the magnets and valve spindle 12 rigidly attached to armature 15 have moved down so far, under their own weight and under load of spring 13, until they with their magnetically attached armature 21 rest either on the fully compressed spring 23 or on a stop 20 on the support 20, and thereby close the contacts 24. The flow of gas through the still widely enough opened gasway 7 is not impeded.

As is further shown in FIG. 4, a branch gas supply from main pipe 34 goes from gas outlet connection 3 to the pilot burners 30, 31, 32, 33. Between the branch and the main burners 35, 36, 37, 38, fed by the main gas supply, is a magnetic valve 39 Wired in circuit with the contacts 24 and in that circuit is also a line switch 40 and a room thermostat 41. As soon as the contacts 24 and line switch 49 and room thermostat 41 are closed,

the magnetic valve 39 is opened and gas flows through it on the main pipe to the main burners 35 to 38 where it is ignited by the already lighted pilot fiames at 30 to 33. The installation is then in operation as shown in FIG. 4.

If for any reason even one of the pilot flames is extinguished or the current from any thermocouple fails, the corresponding electromagnet and/or the armature 15 with fixed valve stem 12 drops at once. The valve plate 11 aided by spring 13 then immediately shuts gasway 7. At the same time the contacts 24 are opened by the action of spring 23 and current to magnetic valve 39 is cut off, so that both the flame control device and the magnetic valve shut simultaneously and the magnets 16, 17, 18 resume their position of rest as shown in FIG. 2

When the space to be heated reaches the temperature to which room thermostat 41 is set, current to magnetic valve 39 ceases and it shuts at once. The pilot flames however remain alight and are extinguished only when one of the thermoelectric currents fails or a main gas cook (not shown) is turned otf.

FIG. 5 shows the pilot gas valve as in FIG. 1 assembled as a unit with the main gas valve. In addition, hot wire ignition coils 30', 31, 32, 33 are wired in series and located at pilot burners 30 to 33. They glow when switch 46 in series with the primary winding of a transformer 45 is closed by pressing in press knob 9 to supply current to the hot wire ignition coils 30 to 33'. On pressing the knob 9 further in, the push rod 10 lifts the valve plate 11 from its seat, allowing gas to pass from the gas inlet chamber 4 and gasway 7 to the pilot burners 30 to 33. On pressing the knob 9 still further in, the valve stem 12 with its fixed armature 15 with magnets 16, 17, 18 upon it are further raised until armature 21 meets the support 20. As pressing in knob 9 closes the switch 46 of circuit of transformer 45, the hot wire ignition coils 30' to 33' receive current from the secondary winding of the transformer and glow, and so light the pilot gas at the pilot burners. A spark igniter can be substituted for the hot wire ignition coils. The thermocouples 29 at each pilot flame then generate thermoelectric currents which energizes their magnets, which now remain with armatures and 21 adhering to one anotheradopting the operating position shown in FIG. 5, with press knob 9 released and contacts 24- closed as shown in FIG. 4. On releasing press knob 9, current supply to the primary winding of transformer 45 is interrupted and the hot wire ignition coils are switched oil. The valve plate St) is lifted from its seating by return spring 3, which is stronger than opposing spring 51, and permits gas to pass through the now opened gasway 7 to main burners 35 to 33 and there to be lighted by the pilot flames. The installation is then in the operating position shown in FIG. 5.

An indicating lamp 53 in the line circuit lights up to indicate that contacts 24 are closed and that the installation is in operation.

If, in the assembly of FIG. 5, for any reason one of the pilot flames is extinguished or one of the thermoelectric currents fails, valve plate 11 closes the gasway '7 to both main burners 35 to 38 and to pilot burners 30 to 33 immediately. The installation is put into operation again in the manner already described.

The invention is claimed as follows:

1. A valve for use with a plurality of gas burners each having an associated thermocouple generating electricity when the respective burner is operating, said valve including: a valve body having a gas inlet connection, a gas outlet connection and a gas passage between the two connections; a valve closure device in said passage and movable between a first position at which said passage is closed and a second position at which said passage is open to permit gas .to how from the inlet to the outlet connection; first means connected to the closure device to urge the device to the first position; starting means operatively associated with the closure device to permit the device to be moved to the second position; and control means operatively associated with the closure device and adapted to be connected to the thermocouples to hold the closure device in the second position so long as electricity from each thermocouple is delivered to said control means, said control means including a plurality of electromagnet members corresponding in number to the number of thermocouples with each member including means by which it may be connected to a respective thermocouple, a plurality of armature members corresponding in number to the number of electromagnet members, said electromagnet members and said armature members being positioned in series with an armature member in juxtaposition with each electromagnet member and with one member at one end of said series and another member at the other end of said series whereby when the electromagnet members all are energized a unitary pile is formed by the members with a given dimension between the two end members, said electromagnet members having sufficient strength when all are energized to hold said closure device in the second position against the urging of said first means, the one member being attached to the closure device, the other member being connected to the body and positioned a distance from the one member, said distance when said device is in the first position being greater than said given dimension, whereby the deenergization of any one electromagnet member will release said pile and permit said first means to move the closure device to the first position.

2. A valve as set forth in claim 1, wherein the valve body has a second gas outlet and a passageway connecting the second outlet connection with the said passage between the first outlet connection and the closure member; said valve including a second closure device in said passageway, and movable between one position at which said passageway is open and another position at which said passageway is closed, said second device being operatively connected to said starting means to be moved from said one to said another position when the starting means moves the first device to the second position, and resilient means operatively connected to the second device to resiliently urge the second device to the one position.

3. A valve as set forth in claim 1, and including normally open electrical switch means operativcly connected to said control means to be closed when said members are positioned to form said unitary pile.

4. A gas control valve including: a valve body having a wall dividing the interior of the body into two chambers, said wall having an opening therethrough between the chambers and defining an annular valve seat in one of said chambers about the opening, said body having a gas inlet connection communicating with the one chamber and a gas outlet connection communicating with the other chamber; an actuating rod positioned generally normal to said seat in alignment therewith and extending from the one chamber through the body to the exterior thereof, said rod being movable axially with respect to said seat; a valve closure within the one chamber and in sealing contact with said seat, said closure being affixed to said rod; control means mounted on said body externally thereof and connected to said rod to hold the rod and closure away from said seat after the closure has been otherwise displaced therefrom, said control means including a plurality of electromagnet members each having a corresponding armature member immediately adjacent thereto, said members being positioned in series with one member at one end of the'series and another member at the other end of the series, said one member being secured to the rod externally of the body, means interconnecting the other member and the body to restrain said other member from movement toward the one member beyond a position at which there is at least one space between adjacent members of the series, the members between said two end members having means to provide for movement along a line between the two end members, each electromagnet member having electrical connections by which it may be energized separately from the other electromagnet members; means operatively connecting the closure and body to urge the closure against said seat; a plunger extending through the body into the other chamber in alignment with said opening, said plunger being movable with respect to the body toward and away from said closure; and means operatively connecting the plunger and body to resiliently resist movement of the plunger toward the closure, whereby the plunger may be pressed against the closure and moved to displace said closure from said seat against said urging and move the members together to close said space.

5. A valve as set forth in claim 4, having means operatively connected to the plunger and positioned in the other chamber to close said opening when said plunger is moved toward the closure.

6. A valve as set forth in claim 5, wherein said wall defines adjacent valve seats about the opening and on opposite sides of the wall, said wall having a gas passageway therein communicating with said opening and defining a gas connection externally of the valve, and said means to close said opening includes a second closure in the other chamber in alignment with the opening and resilient means to urge the second closure against the adjacent seat when said plunger is moved toward the closure in the one chamber, said plunger including means to move the second closure away from its seat when the plunger is released.

7. A gas control valve including: a valve body having a wall dividing the interior of the body into two chambers, said wall having an opening therethrough between the chambers and defining an annular valve seat in one chamber about the opening, said body having a gas inlet connection communicating with the one chamber and a gas outlet connection communicating with the other chamber; an actuating rod positioned generally normal to said seat in alignment therewith and extending from the one chamber through the body to the exterior thereof, said rod being movable axially with respect to said seat; a valve closure within'the one chamber and in sealing contact with said' seat, said' closure being afiixed to saidrod; controlmeans mounted on said body externally thereof and connected to said rod to hold the rod and closure away from said seat after the closure has been otherwise displaced therefrom, said control means including a plurality of electromagnet members each having a corresponding armature member immediately adjacent thereto, said members being positioned in series with one member at one end of the series and another member at the other end of the series, said one member being operatively connected to the rod externally of the body, means interconnecting the other member and the body to restrain said other member from movement toward the one member beyond a position at which there is at least one space between adjacent members of the series, the members between said two end members being mounted for movement along a line between the two end members, each electromagnet member having electrical connections by which it may be energized separately from the other electromagnet members; means operatively conmeeting the closure and body to urge the closure against said seat; and starting means operatively associated with the closure to permit the closure to be moved to the position at which said members are together and said space closed.

8. A valve as set forth in claim 7, wherein said members are annular and encircle said actuating rod.

9. A valve as set forth in claim 7, wherein said one member is adjacent the closure and the other member is farthest from the closure.

10. A gas control valve including: a valve body having a Wall dividing the interior of the body into two chambers, said wall having an opening therethrough between the chambers and defining an annular valve seat in one chamber about the opening, said body having a gas inlet connection communicating with the one chamber and a gas outlet connection communicating with the other chamber; an actuating rod positioned generally normal to said seat in alignment therewith and extending from the one chamber through the body to the exterior thereof, said rod being movable axially with respect to said seat; a valve closure within the one chamber and in sealing contact with said seat, said closure being afiixed to said rod; control means mounted on said body externally thereof and connected to said rod to hold the rod and closure away from said seat after the closure has been otherwise displaced therefrom, said control means including a plurality ,of electromagnet members each having a'corresponding, armature member immediately adjacent thereto, said members being positioned in series with each encircling said actuating rod, and with one member at one end of the series and another member at the other end of the series, said one member being attached to the actuatingrod, the other member being mounted on the body for limited movement parallel to the longitudinal axis of the actuating red, the members between said two end members being mounted for movement along a line between the two end members, each electromagnet member having electrical connections by which it may be energized separately from the other electromagnetmembers; resilient means operatively connecting the closure and body to resiliently urge the closure against said seat; resilient means urging said other member away from the closure; starting means operatively associated with the closure to permit the closure to be moved to the position at which said members are-together and said space closed; and an electrical switch operatively connected to the member at'the other end of the series to be actuated by the movement of said member.

11. A valve as set forth in claim 10, wherein said starting means includes a plunger extending through the body into the other chamber in alignment with said opening,

said plunger being movable with respect to the body toward and away from said closure; and means operatively connecting the plunger and body to resiliently resist movement of the plunger toward the closure, whereby the plunger may be pressed against the closure against said resistance and moved to displace said closure from said seat against said urging and move the members together to close said space; and a normally open electrical switch operatively connected to the plunger to be closed when the plunger is positioned to displace the closure from said seat.

12. In a gas valve having a valve closure movable between a valve opened position and a valve closed position, resilient means urging said closure from said opened position toward said closed position, and a control device to normally hold said closure in the opened position, the improvement of said control device comprising: a plurality of electromagnet means sequentially positioned and operable to form a pile upon all being energized with one said means at one end of said pile and another said means at the other end of the pile, said one means being fixed and the other means being connected to said closure, said electromagnet means upon all being energized to hold said closure in said opened position and being operable upon any one becoming deenergized to release said closure to move to said closed position in response to said resilient means; and thermocouple means for each electromagnet means to energize the respective electromagnet means so long as said thermocouple means is heated.

References Cited in the file of this patent UNITED STATES PATENTS 1,431,119 Kellum Oct. 3, 1922 2,268,960 Ray Ian. 6, 1942 2,873,069 Matthews Feb. 10, 1959 2,959,219 Hajny Nov. 8, 1960 2,959,650 Hajny Nov. 8, 1960 FOREIGN PATENTS 6,753 Great Britain June 3, 1885 806,543 Great Britain Dec. 31, 1958

Claims (1)

12. IN A GAS VALVE HAVING A VALVE CLOSURE MOVABLE BETWEEN A VALVE OPENED POSITION AND A VALVE CLOSED POSITION, RESILIENT MEANS URGING SAID CLOSURE FROM SAID OPENED POSITION TOWARD SAID CLOSED POSITION, AND A CONTROL DEVICE TO NORMALLY HOLD SAID CLOSURE IN THE OPENED POSITION, THE IMPROVEMENT OF SAID CONTROL DEVICE COMPRISING: A PLURALITY OF ELECTROMAGNET MEANS SEQUENTIALLY POSITIONED AND OPERABLE TO FORM A PILE UPON ALL BEING ENERGIZED WITH ONE SAID MEANS AT ONE END OF SAID PILE AND ANOTHER SAID MEANS AT THE OTHER END OF THE PILE, SAID ONE MEANS BEING FIXED AND THE OTHER MEANS BEING CONNECTED TO SAID CLOSURE, SAID ELECTROMAGNET MEANS UPON ALL BEING ENERGIZED TO HOLD SAID CLOSURE IN SAID OPENED POSITION AND BEING OPERABLE UPON ANY ONE BECOMING DEENERGIZED TO RELEASE SAID CLOSURE TO MOVE TO SAID CLOSED POSITION IN RESPONSE TO SAID RESILIENT MEANS; AND THERMOCOUPLE MEANS FOR EACH ELECTROMAGNET MEANS TO ENERGIZE THE RESPECTIVE ELECTROMAGNET MEANS SO LONG AS SAID THERMOCOUPLE MEANS IS HEATED.

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