US2290048A - Safety device for heating and other apparatus - Google Patents

Description

July 14, 1942.

SAFETY DEVICE FOR HEATI Filed Dec.

- Q j i @2 C. V. HILDEBRECHT us AND OTHER APPARATUS @afld? Patented July 14, 1942 SAFETY DEVICE-FOR HEATING AND OTHER APPARATUS Charles V. Hildebrecht, Chicago, Ill., assignor to Milwaukee Gas Specialty Company, Milwaukee, Wis., a corporation of Wisconsin Application December 12, 1938, Serial No. 245,076

19 Claims.

tion, Serial No. 239,799, filed November 10, 1938. r

I More particularly, the invention relates to safety devices of the general character in which an electromagnet connected in circuit with a thermocouple is adapted to beenergized by the thermo-electric current set up by the thermocouple as long as the burner, to the heat of which the thermocouple is subjected, such as a pilot burner, is lighted, and when so energized, maintains a valve or other controlling member for controlling the supply of fuel or operative energy to the apparatus in open or operating position; cessation of the holding action ofthe electromagnet, upon extinguishment of the burner or upon opening of the thermo-electric circuit, releasing the valve or controlling member for movement to closed or safety position shutting off the supply of fuel or operative energy to the apparatus; One of the main objects of the present invention is to provide a tripping and resetting combination generally such as disclosed in my above identified copending application and of a character not only automatically to maintain the supply of fuel to the burner as long as it is desired to supply heat therefrom and automatically to shut off the fuel supply when heat from the bumer is not desired and to set up the supply of fuel when heat from the burner is again desired, but,

further, automatically to shut oi? the supply of fuel to the pilot burner with the shutting off of the supply of fuel to the main burner and to reestablish the supply of fuel to the pilot burner and automatically ignite the same in the resetting operation which reestablishes the supply of fuel to the main burner.

It is also an object of the present invention to prevent overheating in the event of failure of the circuit other than the i thermo-electric circuit, and, more particularly, to avoid failure to trip the electromagnetlto release the valve or controlling member for movement to closed or safety position when, for example, the other'circuit fails and a desired temperature is exceeded or other abnormal defective or insuflicient functioning or non-functioning of the apparatus occurs Further objects and adv ntages of the invention will appear from the following detailed de-'- scription, taken in connection with the, 'acoom panying drawing in which the single figure is a diagrammatic view, partly in sectiomoi' an'illustrative embodiment of the present invention.-

Referring to the drawing, the burner I0 is any suitable or preferred main burner-by way of example, the main burner for a water heater or for a space or room heater, or it may be the main burner for certain types of ovens or other heating apparatus, or any other burner.

A pipe, indicated diagrammatically at H, supplies gaseous or any other suitable fuel to the burner ID. A valve body shown fragmentarily at I2 is connected into the fuel supply pipe I I. The valve body I! has a valve opening or port I3. Disposed in juxtaposition to the burner I0 is a pilot burner M which maintains a pilot flame l5 for igniting the main burner. The pilot burner i4 is supplied with fuel by a tube l6 which is preferably connected through a port H with the valve opening l3 between the valve seats l8 and I9 at opposite ends thereof.

A valve 20 is adapted to seat upon the seat I8 at the outer end of the valve opening l3 to shut off the fuel supply to the main burner l0 and also the fuel supply to the pilot burner Id. The valve 20 is connected by a;valve'stem 22 to an armature 23, and a helical spring 24 surrounds the valve stem with one end engaging the valve 20 and the other end engaging a fixed part 25 of the control device. The spring 2| is normally under compression when the armature is in attracted position, but when the electromagnet, indicated generally at 28, is energized and the armature 23 is held in attracted position thereby,

the spring 24 is prevented from moving the valve 20 to closed position engaging the valve seat N and the pilot burner.

Upon cessation of the holding action of the electromagnet 28 as, for example, upon extinguishment of the pilot flameat the pilot burner It or upon tripping of the electromagnet as will hereinafter appear, the armature 23 and connected valve 20 are released, whereupon the valve -20 is moved by the spring 24 into engagement with the valve seat It to shut oil! the supply of fuel to the main burner and also to the pilot burner.

The electromagnet 28 cpmprises a magnet frame 30 having energizing coil means. In the illustrated embodiment of the invention, the magnet frame It is of generallyu shaped form, and the coil means 32 surrounds each of the legs of the magnet frame. It is to be understood that the electromagnet may be of any other suitable or; preferred form; The coil means 32, instead of surrounding each of the legs or'tlie magnet frame, may surround only one leg, and a trip coil may be provided around the other leg as disclosed and for the purposes set forth in my copending application Serial No. 239,799, filed November 10, 1938, and in the copending application of John H. Thornbery and Theodore A. Wetzel, Serial No. 283,572, filed July 10, 1939. The coil means 32 is connected in circuit with the a thermocouple 35 as will presently be described.

disclosed in Oscar J. Leins Patent No. 2,126,564,

granted August 9, 1938, or it may be in the form of any of the thermocouples or multiple thermocouple devices disclosed in the copending application of Guido Wunsch and Josef Schuppert,

Serial No. 738,370, filed August 3, 1934, or of any other suitable or preferred form.

One terminal of the coil means 32 is connected through a conductor 38 to the internal thermocouple element of the thermocouple 35, and the other terminal of the coil means 32 is connected by a conductor 46 in circuit with a fixed contact 42. supported adjacent the contact 42 and insulated 1 therefrom as indicated at 4'4. The contact 43 is connected in circuit with the external metallic tubular thermocouple element of the thermocouple 35 by a conductor 45. The spring contact 43 is preferably tensioned normally to engage the contact 53 with the contact 42 at 46.

A second fixed contact 48, positioned in spaced relation with respect to the contact 42, is connected, for example, through the Winding of an electromagnet 49, a conductor 52, relay 53, and conductor 54, to the conductor 55 of a circuit 55, 56. The circuit comprising the conductors 55, 56 is connected to a suitable source of current, for example through a transformer Eill to an alternating current circuit 58. The circuit 58 may, for example, be an alternating current lighting circuit or any other alternating current circuit supplied by a suitable source ,of alternating current (not shown), although of course a direct current resetting circuit, as well as other resetting arrangements, may be employed within the scope of the broader aspects of the present invention.

A. thermally sensitive member or thermostat 60 is fixedly supported at one end at 62 and carries, at its opposite end, a contact 63 backed by an insulating piece 64, the contact 63 and insulating piece 64 being moved by the action of diflerent temperatures upon the thermostat 60. For example, upon a predetermined maximum temperature adjacent the thermostat, the insulating piece 64 engages the projecting end of the contact spring 43 and separates the same from the contact 42 to open the thermo-electric circuit at 46. temperature adjacent the thermostat the con tact 63 engages the contact 48.

The thermostat 60 shown in the drawing comprises a pair of strips formed of dissimilar metal and secured together, the strips having different coeflicients of expansion, and the thermostat has i a bimetal spiral or coiled portion as shown. The

A spring contact 43 is fixedly.

Upon a predetermined minimumcircuit for conducting current from the circuit 55, 56 to the contact 53. This may be varied so that the bimetal thermally sensitive element is removed from the electric circuit. Moreover, the thermostat maybe of any other suitable or preferred type, and I contemplate other devices such as a pressure responsive device or a humidity responsive device, or a device responsive to some other conditions for actuating the contact 63 and insulating piece 64.

The reset means for resetting the armature 23 into attracted position and the valve 29 to open position comprises a reset stem '60. The resetting electromagnet 'H cooperates with the stem 10 for the purpose of actuating this stem inwardly to reset the device by engaging the valve 20 and moving the valve to open position and the armature 23 to attracted position. In the embodiment of the invention illustrated in the drawing, the reset electromagnet H has a magnet frame l2 with the magnet coil 73 surrounding the same. The stem 70 is preferably formed of non-ferrb magnetic material, and its outer end carries an armature 75 formed of a suitable magnetic material. When the circuit through the coil l3 is closed, the electromagnet H is energized and moves the armature 15 to attracted position, this movement of the armature actuating the reset stem inwardly to reset the device.

For the purpose of shutting ofi the supply of fuel to the main burner during the resetting operation, the reset stem 10 is'provided with a valve member E8 of the general character disclosed and claimed in my prior Patent No. 2,114,446, granted August 19, 1938. A stop 19 fixed on the stem '50 .limits the outward movement of the reset stem, and a coiled spring 89, interposed between the stop 19 andthe valve 18 which is loose on the stem, moves the valve 78 yieldingly to closed position engaging the valve seat 89 by the movement of the stem 10 in the resetting operation. A coiled spring 82, interposed between the valve l8 and a fixed part of the control device, .moves the valve 18 to open position and the armature E5 to retracted position upon completion of the resetting operation. One terminal of the reset coil 13 is connected by a conductor 84 to the conductor 55 of the circuit '55, 56, and the other terminal of the coil 13 is connected through a conductor 85 to a eon-' tact 86 in juxtaposition to the electromagnet 49. A leaf spring 81, fixedly supported at 88 and connected at its fixedly supported end by a conductor 90 with the conductor 56 of the circuit 55, 56, carries a contact 9! which is adapted to engage the contact 86 for closing the circuit through the coil 13 of the reset electromagnet whereby the resetting operation is secured. The leaf spring is tensioned to open circuit position against a stop 89 as shown in the drawing. An arm may be employed instead of the leaf spring 81, and this arm may .be pivotedat 88 and normally held inppen circuit position by a suitable spring. The contact 86 may be in the form of a leaf spring carrying a contact for cooperation with the contact 9 I; as shown.

The free end of the spring or arm 81 projects beyond the contact 9|, and the electromagnet 49 is provided with an armature 94 pivoted, for example, at 95. The armature 94, upon completion of the circuit through the electromagnet 49, is actuated to attracted position, and, by such actuation, engages the. projecting end of the spring or arm 81 and moves the contact 9| into engagement with. the contact 86 to close the reset coil circuit 84, 05. A spring 00, connected to the armature 04 at one end and fixedly anchored at the other end, returns the armature 04 to retracted position when the electromagnet 40 is deenergized.

For the purpose of automatically igniting and.

conductor I03 and conductor 05 to the contact 1 means at 85. k I

The relay at 53 is shown as of a form generally similar to that disclosed in the copending application of Clarence Wantz, Serial No. 733,722, filed July 5, 1934. Any other relay or equivalent device is contemplated within the scope of the present'invention.

The operation of the device is as follows:

When the pilot flame I5 is burning, the heat thereof upon the thermal Junction 30 of the thermocouple produces a thermo-electric current in'the coil 32 and the connected thermoelectric circuit. The magnet frame 30 and armature 23 are preferably formed of an alloy of relatively low magnetic reluctance'and, as a result, with the switch 42, 43 closed at 40, the relatively weak thermo-electric current produces a magnetic force of sufficient strength so that when the armature 23 is placed in contact with the pole ends of the magnet frame the magnetic attraction holds'the armature in attracted po-- sition with a force greater than the force exerted by the spring 24, thereby holding the valve 20 open, so long as the pilot flame is burning, and

the contacts 42, 43 closed at 45. Fuel then passes through the pipe II to the main burner I0, and through the .pipe II, port I1 and tube I to the pilot burner I4.

.If the pilot flame at I is extinguished, the

holding action of the electromagnet ceases to be sufficient to hold the armature 23 in attracted position and the spring 24 moves the valve 20 to closed position. The closing of the valve 20. "shuts off the supply of fuel to themain burner I0 and also to the pilot burner I4.

On the other hand, with the pilot burner I4 ignited and the valve 20 held open by the thermo-electric current developed by the pilot bum-' magnet ceases to be suflicient to hold the armature 23 and valve 20 in attracted position and the spring 24 moves the valve-to closed position to shut off the supply of fuel to the main burner and to the pilot burner.

electromagnet. The armature I0 is attracted and actuates the reset stem I0 inwardly to reset the arma e 23 to attracted positidn and the valve 20 to open position. If the piiot burner is lighted, the energization of the lectromagnet 20 thereby will retain the armature 2s m attracted position and the valve 20 open.

To prevent the escape of unburned fuel from the .main burner during the resetting operation and until the supply of fuel is set up to the pilot burner and this burner has been ignited or reignited, the valve 10 operates to shut off the supply of fuel to the main burner during the resetting operation. In the inward movement. of the stem 10 in the resetting operation, the valve 20 is opened and sets up a supply of fuel throughthe valve opening I3, but the valve 10 immediately closes off the supply of fuel to the main burner.

Fuel then passes out through the port I1 and tube I5 to the pilot burner. The pilot burner being extinguished so that the thermocouple is not heated thereby, the relays 53 will be in the position with the igniter circuit closed at I20. The circuit from one side of the spark gap igniter I00 is thereby completed through the conductors I02 and 54 to one side of the circuit 55, 56, and from the other side of' the circuit 55, 56 through the closed contacts 00, 0|, and conductors 85 and I03, to the other side of the spark gap igniter. As a result, sparking occurs across the spark gap igniter, and this ignites thefuel issuing from the pilot burner to form the pilot flame l5.

As soon as the pilot burner I5 is thus ignited it heats the junction 35 of the thermocouple and, as a result, the relay 53 is, operated to open the circuit at I20 by the thermo-electric current. I

The opening of the relay 53 thus opens the circuit for the igniter I00 and also the circuit for the electromagnet 40., During the time the electromagnet 40 is energized and until the pilot burner is ignited and has heated the thermocouple, the switch 00, 01 is held closed at 8|, thereby maintaining energization of the reset coil 13 and holding the armature 23 in attracted position and the valve-20 open as well as the valve 18 closed,'until the thermocouple is heated by the pilot flame and thermo-electric current is set up to energizelthe the space or room which is heated. Other con- Where the temperature to which the the'nnocircuit for the electromagnet. 40, closes the conts 0|, 80. This closes the circuit 84, 85 for the resetting coil I3 which energizes the resetting electromagnet 28 sumciently to hold the armature 23 attracted and the valve 20 in open position', whereupon the thermo-electric current, by opening the relay I3 at I28 and deenergizing the electromagnet 40, opens the reset circuit 04, at 0|. The reset stem is thereupon projected outwardly by the spring 82, opening the valve 18 to provide a supply of fuel for the main burner, the valve 20 being retained open by the thermoelectric current.

Where a thermally responsive control is provided at 00, the thermostat thereof may, as already pointed out, be of any suitable or, preferred form. Where the apparatus is employed in connection with a water'heater, the thermostat may be subject to the temperature of the water in the tank, and where the apparatus is employed in connection with a. space or room heater, the thermostat may be subject to'the temperature of trols at 00 will be subject to other conditions at which it is desired to trip and reset the device as herein described.

with the present invention, the valve .20 is tripped and reset automatically upon the occurrence--- of predetermined conditions. The fuel supply for the pilot burner is arranged to be shut on by the valve 20 which shuts off the fuel supply By opening the thermo-electric circuit at at at a predetermined maximum temperature, the electromagnet 28 is tripped and the valve 2t closed at that time regardless of the circuit 58. Overheating, therefore, cannot result, even upon failure of the line 58.

The spark gap igniter Hill is operated by the means 60 which operates the reset means, and, as a result, the fuel which issues from the pilot burner is ignited. The pilot burner, upon being. thus ignited, heats the thermocouple, which sets upon a thermo-electric current, thereby energizing the electromagnet 28 to hold the valve 28 open, the thermo-electric current also opening the relay 53 at E28. The opening of the relay at H discontinues the operation of the igniter and deenergizes the electromagnet 39 so that the reset circuit is opened. The reset stem is then actuated outwardly as previously set forth, and the valve 718 moves to open position to set up the desired supply of fuel for-the main burner.

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

I claim:-

I. Safety device for heating and other apparatus comprising, in combination, heat generating means, pilot means for said heat generating means, means to control the supply of operative energy to said heat generating means and said pilot means, an igniter for said pilot means, a thermocouple subject to the heat of said pilot means, an electromagnet connected in circuit with said thermocouple and adapted to cause said control means to supply operative energy to said heat generating means and said pilot means while said pilot means is operative and to shut oil the supply of operative energy to said heat generating means and to said pilot means when said pilot means becomes inoperative, means for resetting said electromagnet and said control means to operative position to supply operative-energy to the apparatus and for rendering said igniter operative, and means controlled by said thermocouple for rendering said resetting means and said igniter inoperative when said electromagnet is operative to cause said control means to supply operative energy to said heat generating means and to said pilot means. I

2. Safety device for heating and other apparatus comprising, in'combination, heat generating means, pilot means for said heat generatingmeans, means to control the supply of operative energy to said heat generating means and said pilot means, -an igniter for said pilot means, a thermocouple subject to the heat of said pilot means, an electromagnet connected in circuit with said thermocouple and adapted to cause said control means to supply operative energy to said heat generating means and said pilot means while said pilot means is operative and to shut off the supply of operative energy said control means to operative position to sin aee oie ply operative energy to the apparatus and for rendering said i'gniter operative, means con-- trolled by said thermocouple for rendering said resetting means and said igniter inoperative when said electromagnet is operative to cause said cor; trol means to supply operative energy to saiz. heat generating means and to said pilot means, and means subjectto abnormal, defective, or insufficient or non-functioning of the apparatus for tripping said electromagnet to shut off the supply of operative energy to said heat generating means and said pilot means.

3. Safety device for heating and other appa" ratus comprising, in combination, heat generating means, pilot means for said heat generating means, means to control the supply of operative energy to said heat-generating means and said pilot means, an igniter for said pilot means, a thermocouple subject to the heat of said pilot means, an electromagnet connected in circuit with said thermocouple and adapted to cause said control means to supply operative energy to said heat generating means and said pilot means while said pilot means is operative and to shut oil the supply of operative energy to said heat generating means and to said pilot means when said pilot means becomes inoperative, means for resetting said electromagnet and said control means to operative position to supply operative energy to the apparatus and for rendering said igniter operative, means controlled by said thermocouple for rendering said resetting means and said igniter inoperative when said electromagnet is operative to cause said control means to supply operative energy to said heat generating means and to said pilot means, and means subject to abnormal, defective, or insuflicient or nonfunctioning of the apparatus for tripping said electromagnet to shut oil the supply of operative energy to said heat generating means and said pilot means, said resetting means and said igniter being controlled by another condition of the apparatus and by said thermocouple.

4. Safety device for heating and other apparatus comprising, in combination, heat generating means, pilot means for said heatgenerating means, ,means to control the supply of operative energy to said heat generating means and saidpilot means. an igniter for said pilot "means, a thermocouple subject to the heat of said pilot means, an electromagnet connected in circuit with said thermocouple and adapted to cause said control means to supply operative energy to said heat generating means and said pilot means while said pilot means is operative and to shut off the supply of operative energy to said heat generating means and to said pilot means when said pilot means becomes inoperative, means for resetting said electromagnet and said control means to operative position to supply operative energy to the apparatus and for rendering said'igniter operative, means controlled by said thermocouple for rendering said resetting means and said igniter inoperative when said electromagnet is operative to cause said control means to supply operative energy to said heat generating means and to said pilot means, and means actuated to operative position by the resetting operation to shut off the supply of operative energy to the heat generating means during the resetting operation.

5. Safety device for heating and other apparatus comprising, in combination, means to control the supply of operative energy to the apparatus, heat generating means, pilot means for magnet inoperative.

said heat generating means, a thermocouple subject to the heat of said pilot means, an electromagnet connected in circuit with said thermocouple and adapted to cause said controlling means to supply operative energy to the apparatus while said pilot means is operative and to shut oil the'supply of operative energy to the apparatus when said pilot means becomes inoperative, means subjectto a condition of said ap-' paratus for opening the circuit including said thermocouple and said electromagnet to shut oil. the supply of operative energyto the apparatus when the functioning of the apparatus is such as not to require a supply of operative energy, means other than said electromagnet alone and subject to another condition of the apparatus for' resetting said electromagnet and said controlling means to operative position to maintain the supply of operative energy to the apparatus when the functioning of the apparatus is such as to require a supply of operative energy thereto, an igniter for said pilot means, and means controlled by the thermocouple for rendering said igniter and said resetting means inoperative when the pilot flame is established and said electromagnet energized by the thermo-electric current set up by the thermocouple.

6. Safety device for heating and other apparatus comprising, in combination, means to control the supply of operative energy to the apparatus, heat generating means, pilot means for said heat generating means, a thermocouple subject t the heat of said pilot means, an electromagnet connected in circuit with said thermocouple and adapted to cause said controlling means to supply operative energy to the apparatus while said pilot means is operative and to shut off the supply of operative energy to the apparatus when said pilot means becomes inoperative, means other than said electromagnet alone for resetting said electromagnet and said controlling means to operative position to supply op'erative energy to said heat generating means and said pilot means, an igniter for said pilot means, and thermally responsive means for opening the thermo-electric circuit including said electromagnet and said thermocouple at a predetermined maximum temperature and for rendering said re-" setting means and said igniter operative ata predetermined minimum temperature.

7. In a device of the character described, in combination, a burner, a fuel supply pipe leading to said burner, a valve in said pipe, a supply pipe for a pilot light in juxtaposition to said burner, an electromagnet, an armature for said electromagnet which, when attracted, maintains said valve in open position and, when retracted, compels closing of said valve, a thermocouple placed in position to be heated by said pilot light and connected incircuit with said electromagnet, a

second electromagnet connected in circuit with a source of current and adapted for resetting said armature to attracted position, an igniter for said pilot light connected in circuit with said second electromagnet, and relay means controlled by the thermo-electric current generated by the heat of the pilot'light on the thermocouple for rendering said igniter and said second electro- 8. In a thermoelectric control apparatus for a burner, the combination with a burner, a fuel burner, an electromagnet, an armature for said electromagnet which, when attracted, maintains said valve in open position, and when retracted frees said valve for movement to closed position, and thermocouple placed in position to be heated by said pilot light and connected in circuit with said electromagnet so as to energize s'aid electromagnet sufliciently to hold said armature in attracted position and said valve in open position, said valve being incapable of being actuated to open'position by the thermo-electric current generated by the heat of the pilot light on said thermocouple, of a second electromagnet connected in circuit with a source of current and adapted for resetting said armature to attracted position and said valve to open position, and means for interrupting the circuit through said second electromagnet upon completion of the resetting operation.

9. Ina device of the character described, in combination, a burner, a fuel supply pipe leading to said burner, a valve in said pipe, a supply pipe for apilot light in juxtaposition to said burner, an electromagnet, an armature for said electromagnet which, when attracted maintains said valve in open position and, when retracted,

compels closing of said valve, a thermocouple placed in position to be heated by said pilot light and connected in circuit with said electromagnet, a second electromagnet connected in circuit with a' source of current and adapted for resetting said armature to attracted position, means subject to the heat supplied by said burner for closing the circuit through said second electromagnet at a predetermined temperature, and means under the control of the thermoelectric current generated by the heat of the pilot light on said thermocouple for interrupting the circuit through said second electromagnet upon energization of said first electromagnet.

10.- In a control device for heating and other apparatus, in combination; a main burner, a fuel supply pipe leading to said burner, a valve in said pipe, a fuel supply pipe for a pilot light in juxtaposition to said burner, an electromagnet, an armature for said electromagnet which, when attracted, maintains said valve in open position and, when retracted, frees said valve for movement to closed position, a thermocouple placed in position to be heated by said pilot light and connected in circuit with said electromagnet,

means subject to a condition of said apparatus for opening automatically, upon the occurrence of such condition, the circuit including said thermocouple and said electromagnet to shut oil the supply of fuel to said main burner when the functioning of the apparatus is such as not to require a supply of fuel to said main burner, means independent of said electromagnet and subject to another condition of the apparatus other than the heat of thepilot" light on the thermocouple for automatically resetting said armature to attracted position and said valve to open position to establish and maintain a supply of fuel to said main burner when the functioning of the apparatus is such as to require the same, and means under the control of the thermoelectric current generated by the heat of the pilot light on said thermocouple for disabling, said resetting means upon energization of said electromagnet. v

. 11. In a device .of the character described, in combination,a'burner, a fuel supply pipe leading to said burner, a valve in said pipe, a supply pipe for a pilot light in juxtaposition to said burner, an electromagnet, an armature for said electromagnet which, when attracted, maintains said valve in open position and, when retracted compels closing of said valve, a thermocouple placed in position to be heated by said pilot light and connected in circuit with said electromagnet, a second electromagnet connected in circuit with a source of current and adapted for resetting said armature to attracted position, means subject to the heat supplied by said burner for closing the circuit through said second electromagnet at a predetermined temperature, and a relay in the thermocouple circuit for interrupting the circuit through said second electromagnet upon energiaation of said first electromagnet.

12. In a device of the character described, in combination, a burner, a fuel supply pipe leading to said burner, a valve in said pipe, a supply pipe for a pilot light in juxtaposition to said burner, an electromagnet, an armature for said electromagnet which, when attracted, maintains said valve in open position and, when retracted, compels closing of said valve, a thermocouple placed in position to be heated by said pilot light and connected in circuit with said electromagnet, asecond electromagnet connected in circuit with a source of current and adapted for resetting said armature to attracted position, means subject to the heat supplied loy said burner for closing the circuit through said second electromagnet at a predetermined temperature, ignition means for said pilot light, and a relay in the thermoelectric circuit for interrupting the circuit through said ignition means and the circuit through said second electromagnet upon energization of said first electromagnet.

13. In a control device for heating and other apparatus, in combination, a main burner, a fuel supply pipe leading to said burner, a valve in said pipe, a fuel supply pipe for a pilot light in juxtaposition to said burner, an electromagnet, an armature for said electromagnet which, when attracted, maintains said valve in open position and, when retracted, frees said valve for movement to closed position, a thermocouple placed -in position to "be heated by said pilot light and connected in circuit with said electromagnet,

ill

means subject to a condition of said apparatus for opening automatically, upon the occurrence oi. such conditiomthe circuit including said thermocouple and said electromagnet to shut oil the supply of fuel to said main" burner when the functioningcf the apparatus is such as not to require a. supply of fuel to said main burner, means independent of said electromagnet and subject to another condition of the apparatus other than the' heat of the pilot light on the thermocouple for automatically resetting said armature to attracted position and said valve to open position to establish and maintain a supply of fuel to said main bumerwhen the fimctioning of the apparatus is such as to require thesame, ignition means for said pilot light; and means under the control ot'the thermoelectric current generated by the heat of the pilot light on said thermocouple for disabling said resetting means and said ignition means upon energlzation of said electromagnet.

14. In a. control device for heating and other apparatus, in combination, a. main burner, a fuel supply pipe leading to said burner, a valveiin said pipe, 1!. fuel supply p pe for a pil t lich ijuxtapositin to said umer, an electromagnet, an armatm'e for said electromagnet which, when and, when retracted, frees said valve for movement to closed position, a thermocouple placed in position to be heated by said pilot light and connected in circuit with said electromagnet, means subject to a condition of said apparatus for opening automatically, upon the occurrence of such condition, the circuit including said thermocouple and said electromagnet to shut off the supply of fuel to said main burner when the functioningof the apparatus isv such as not to require a supply of fuel to said main burner, and means independent of said electromagnet and subject to another condition of the apparatus other than the heat of the pilot light on the thermocouple for automatically resetting said armatureto attracted position and said valve to open position to establish and maintain a supply of.

fuel to said main burner when the functioning of the apparatus is such as to require the same.

15. In a control device for heating and other apparatus, in combination, a main burner, a fuel supply pipe leading to said burner, a valve in said pipe, a fuel supply pipe for a pilot light in juxtaposition to said burner, an electromagnet, an armature for said electromagnet which, when attracted, maintains said valve in open position said second electromagnet automatically to reset said armature to attracted position and said valve to open position to establish and maintain a supply of fuel to said main burner when the funcq .tloning of the apparatus is such as to require the same.

16. In a device of the class described, in combination, heat generating means, means for controlling the supply of operative energy to said heat generating means, a pilot light for said heat generating means, a thermoelectric generator subject to the heat of said pilot light, an igniter for said pilot light, condition responsive means for rendering said igniter operative, and means connected in circuit with said thermoelectric generator and controlled by the thermoelectric current generated by the heat of the pilot light' onv said thermoelectric generator automatically to render said igniter inoperative upon.energization of said thermoelectric generator.

17. In a device of the class described, in combination, a burner, a fuel supply pipe leading to said burner, a valvein said pipe, a pilot light in position to ignite said burner, an electromagattracted, maintains said valve in open position net, an armature for said electromagnet which, when attracted, maintains said valve in open position and, when retracted, frees said valve for movement to closed position, a thermoelectric enerator placed in position to be heated by said pilot li ht and connected in circuit with said electo render said igniter inoperative upon energization of said thermoelectric generator.

18. In a device or the class described, in combination, a burner, a thermoelectric generator subject to the heat of said burner, an igniter for said bumer, condition responsive means for rendering said igniter operative, and means connected in circuit with said thermoelectric generator and controlled by the thermoelectric current generated by the heat of the pilot light on said thermoelectric generator automaticallyto render said igniter inoperative upon energization of said thermoelectric generator.

19. In a device of the character described, in combination, a control dvice having an electromagnet provided with an armature connected to a controlling member and adapted when energized to hold said member in operating position and when deenergized to release said member to] movement, to a safety position, a second electro magnet adapted for resetting. said armature t attracted position and said controlling membei to operating position, means responsive to'thi heat of a pilot light for interrupting the circniiv through said second electromagnet upon completion of the resetting operation, and igniter means connected in circuit with said second electro-- magnet and disabled by the interruption of the circuit through said second electromagnet by said last mentioned means, said control device controlling the fuel igniter by said igniter.

CHARLES V. HILDEBRECHT.

DISCLAIMER .2,290,048.0haflea Hildebrecht, Chicago, Ill. Sum? DEVICE FOR Hm'ni'w AND OTHER Armlu'rus. Patent dated July 14, 1942,. Disclaimer filed July 13, 19:14, by the assigne'e, Milwaukee Gas Specialty Company; the inventor, assentmg, a

Hereby. enter this disclaimer to claims 1, 2, 3, 1'6, and 18 of said patent.

[Ofiicial Gazette Augustl', 1944.]

DISCLAIMER v .2,290,048.-0hafles Hildebrecht; Chicago, 111. Sum? DEVICE FOR Hmvmfia AND OTHER APPARATUB. Patent dated July- 14, 1942,. Disclaimer filed July 13, 19:14 by the assigne 'e, -Milwaakee Gas Specialty Company; the inventor, assentmg, v

Hereby. enbefs this disclaimer to claims 1, 2, 3, 1'6, and 18 of said patent.

[Oflicial Gazette August'lb', 1944.] a

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