US2189829A - Safety device for heating and other apparatus - Google Patents

Description

Feb. 13, I:

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SAFETY DEVICE FOR HEATING AND OTHER APPARATUS Filed Aug. 3, 1954 2 Sheets-Sheet 1 In vemor's:

FehiS, 0. GjwUNscH ET AL 2,

SAFETY DEVICE FOR HEATING AND OTHER APPARATUS I Filed Aug. 5, 1934 2 Sheets-Sheet 2 In ventors:

Patented Feb. 13:, 1940 amaze j PATENT QFFEQE SAFETY DEVICE FOR HEATING AND o'rnEn APPARATUS Guido Wi'msch, Berlin-Steglitz. and .losef Schuppert, Dessau, Germany, assignors to Askania- Werke A. 'G. vormals Central Werkstatt Dessau und Carl Bamberg-Friedenau, a; German.

company Application August 3, 1934, Serial No. 738,370

. In Germany September 28, 1933 10 Claims.

16 Another and more specific object of the invention is to provide a thermocouple and pilot burner comprising a jet member having port means through which fuel is discharged to maintain a pilot flame, there being a fuel supply pipe a. connected to the jet member, and a plurality of thermocouples disposed at circumferentially spaced locations about the jet member, each of the thermocouples comprising a pair of thermocouple elements joined at their outer ends to 2 form a plurality of circumferentially disposed thermal junctions adapted to be heated by the pilot flame, and the device having insulating means surrounding the jet member and insulating the thermocouple elements of each thermocouple from each other. and at least one thermocouple element of each thermocouple from the jet member and means for clamping the thermocouples and insulating means in place upon the jet member so that the parts constitute a unitary 39 device with the plurality of thermal junctions adapted to be heated by the pilot flame main-;

tained in substantially corresponding relation to said flame at circumferentially spaced positions. I

Another object of the invention is to provide in a thermocouple and pilot burner ofthe class described shield means constituting a unitary part of the device and cooperating with the pilot flame to assure heating of all of the thermal 4o junctions at the outer ends of the thermocouples. Another object is to provide an'improved form of thermocouple-unit.

Further objects and advantages of the present invention will appear from the following detailed 45 description, taken in connection with the accompanying drawings, in which: Fig. 1 is a diagrammatic view partly in section of one illustrative embodiment of the invention;

and 50 Figs. 2 to 5 show various illustrative arrangements of the thermocouple means relative to the igniting means or pilot;

In the following description the invention will be described in its application to heating appa- 55 ratus, and more particularly to liquid heating This invention relates to safety devices for apparatus, but it will be apparent to those skilled in the art that broadly the invention is equally applicable to other apparatus in which the use of a safety device is indicated.

Referring to Fig.. 1' the invention is therein 6 shown in its application to heating apparatus using gas as a heat generant. The gas may be supplied from any suitable conventional source of supply (not shown) to a burner or burners 2 through a suitable. passage herein comprising 10 pipes 4 and 6 communicating through a valve seat opening 8 with which cooperates a valve l0. Suitable igniting means, herein a pilot 26 issuing from a burner 24 is provided to ignite the gas from the main burner 2. Controlling means for said valve lllis also provided, said controlling means being preferably heat-responsive so as to be controllable by said pilot or other heating or igniting means. Herein said valve-controlling means will preferably comprise a magnet and '2 thermocouple 22. Said magnet will conveniently be a pot-shaped magnet l2 supported by the upper wall of pipe 4 and over said valve II] which will conveniently comprise .the armature of said magnet, said valve being preferably made as 25 light-as possible. The core l4 and sleeve l6 of said magnet may be integral and will preferably be made of iron having a very low capacity for residual magnetism. An iron alloy containing over of nickel satisfies this condition. The

magnet winding l8 will preferably be of quite thick copper wire, 2 mm. or morein diameter. One end of saidwinding is conductively connected to said magnet while the other end is connected, preferably by a quite thick copper wire 20, with one terminal of'a .thermocouple22. The other terminal of said thermocouple isherein conductively connected to said burner 24 of said gas pilot 26 to which gas is supplied through a pipe 28 connected to the gas supply,

said pipe being herein conveniently connected to the pipe 6 and between said valve seat l0 and the main burner 2. Said terminal is thus conductively connected to, said magnet through the "walls of pipes 28, 6 and 4. The thermocouple 22 is so positioned relativelyto said pilot that junctions or points of union thereof are heated by said pilot. As more fully explained hereinafter one or more thermocouples may be used.

The valve spindle 30 extends through a bearing 32 in the lower wall of said pipe 6 and carries a disk 34 at its free end. The latter is contained in a cylinder 36 also containing a piston 38. This piston carries a central boss 60 supporting a helical spring 42. below said disk 34 and preferably out of contact with the latter when said valve III is in raised position. The rod 88 of said' piston extends through the lower end wall of said cylinder and its free end is connected 5 to a plug 88 having a sliding lit in the cylinder part 88. A helical spring 88 surrounds said rod 88, one end thereof engaging the bottom of said plug and the other the end wall of said cylinder 88, said spring thus tending to press said piston 88 downwardly.

It will be apparent that by pressing upwardly upon the lower end of the plug 88. the piston 88 will be raised, and if the valve III has dropped continued pressure on said plug will raise said valve I0 into position to be attracted by said magnet.

Preferably damping or retarding means will be provided in accordance with the invention to retard downward movement of the piston 38 Q when it has been thus raised. Herein said retarding means comprises a port 58 opening through the lateral wall of said cylinder 38 into a chamber 52 containing. a disk 54 and a helical Y spring 58, one end of which engages said disk 88 and the other end the opposite wall of said chamber and thustends to press said disk against said port. Said disk is provided with a small throttling or choke port 58, the whole thus forming a non-return valve.

80 The operation of the construction so far described is as follows: The valve I8 being in open position and against the magnet I2 as shown in Fig. 1, it will be maintained in that position so long as the pilot 28 remains ignited, as the thera mo-electric current engendered by the heating of the thermocouples 22 by said-pilot energizes said magnet. Gas thus flows freely through the valve seat 8 to the burner 2 and will be thereby ignited by said pilot. Should said pilot 28 become extinguished for any reason, the thermocouples will quickly cool, the thermo-electric current will cease and the magnet being thus de-energized, the valve ID will drop and close the valve seat opening 8 thus cutting off the gas supply to the burner 2 and pilot 28.

To light said burner 2, plug 48 is pressed upwardly thus raising the piston 88. The air in cylinder 88 being thus compressed the disk 58 will be raised from the port 88 against the tension of o spring 88 and air will thus escape from said cylinder through said port 58. Before said piston 88 will have reached its highest position, spring 82 will have engaged said disk 88 and raised said valve I8 from its seat and into contact with as said magnet I2. In thus'raising said valve said spring 82 will be compressed, so that in the highest POSItiOILOf'JSBid valve said spring 82 will be tensioned between the disk 88 and piston 88.

. The burner 2 and pilot being now supplied "'00 with gas can be lighted. 'rlle pilotthen heats said thermocouples 22 thus energizing said magnet which will maintain the valve I8 open so long as said pilot is lighted. Even should plug 48 be immediately released after raising said valve, -86 spring 82 will continue to hold said valve in contact with. said magnet until the, latter becomes sufllciently energised to hold it there, for as previously exhausted rair irom cylinder 88 can reenter the same only very slowly said thl'ottling pol-t remain: u, piston is ,only very slowly.. Consequently before the compressedspring l2 can expand suiliciently to allow II to drop,. tlie thermo-electric currelrtwill have become sufllciently strong to hold "3" mam alian-m n.

ing sleeve.

The pilot or other igniting or heating-means and the thermo-oouples should be relatively positioned s27 that junctions or points of union of said thermocouples shall be well and reliably heated.

Fig. 2 shows two parallel thermocouples 88 and 82 having their points of union at opposite sides of the pilot flame and close to its edge. The two metal wires forming each of said two thermocouples are connected respectively to two an- 8. null 88 and 86 of which the latter forms a clamp- One of the elements of each of said thermocouples, wires 88 and 88 for example, made preferably of constantan, are connected to said clamping sleeve 88, the other elements of 18 each of said thermocouples, copper wires or better still silver wires 82 and 94 are connected to said annulus 84. The parts are assembled by sliding the annulus 88 over the burner 98, placing an insulating sleeve 88 over said an-- nulus 84 and then sliding said clamping sleeve or annulus 86 over said insulating sleeve; A clamping screw I has screw-threaded.

engagement with parallel ears Ill-I08 formed at the ends of said sleeve '8iand serves remov- 2 ably to clamp the parts upon said burner '88. Thermocouple elements 92 and 94 are conductively connected to one end of the magnet winding through annulus 88 and pilot burner 98, while thermocouple elements 88- and 88 are conduc- 8o tively connected to the other end of said magnet winding through said clamping sleeve or annulus 88 and a suitable conductor I82 ior example, clamped in contact with said sleeve by said v clamping screw I00. The arrangement described has the advantage that the thermocouples can always be readily removed and assembled.

Similar arrangements are shown in Figs. 3 to 5. In these, however, a plurality of thermocou- ..ples 88, 88 and 82, 82 are shown having their 4o junctions or points of union interconnected, for example by a ring I88 which may be of one of the metals forming the thermocouples, of silverfor example. V

In Figs. 3, 4 and 5 the pilot flame or other ig- 5 niter or heater means will extend through the ring I88 whereby the points of union will be uni-' iormly heated. Proper heating of the points of union of the thermocouples is assured, even in case of deflection oi the gas jet by drafts or other -51) causes, Fig. 4 shows in perspective how the ring I88 may be reinforced in cross section to give it greater strength. i

The thermo-elements, built according to Figs.

5 and 8, have their hot junctions considerably smaller than the opposite junctions formed by the elements 88, 88 and 88. The ring 86 is, of course, also heated if the pilot flame burns, but to a smaller extent than the hot junctlonswhich, are directly exposed'to' the flame. If the'pilot m name is extinguished, its junctions which were "junctions 'will therefore remain hot longer than 'the previously heated hot. junctions. Consequently, a merino-current in the reverse direction willbe produced when dli- "l8 i'erence between the two junctions is reversed.

This thermo-current m theoppcsite direction has atendencw to energise-theel'ectromagnet in a'reverse'manner -and thereby overcome or practically eliminate the Ii so that the valve control will be permitted to drop practically instantaneously. This is a very importantadvantage of the invention.

It is to be understood that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes of said invention, and it is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

We claim:

1. In combination, a burner for maintaining a flame, an electromagnet having a magnet frame and a winding, a thermocouple comprising dissimilar thermocouple members connected to the winding of said electromagnet and joined to form a hot junction positioned at the edge of the flame to be heated thereby, and an annulus conductively connected to said thermocouple members at the hot junction thereof and encircling the flame maintained by said burner to assure adequate heating of the hot junction of the thermocouple when the flame. is diverted by drafts.

2. In combination, a burner for maintaining a flame, an electromagnet having a magnet frame and a winding, a thermocouple comprising a plurality of dissimilar thermocouple members connected to the winding of said electromagnet and joined to form a plurality of hot junctions positioned at circumferentially spaced positions about the edge of the flame to be heated thereby, and an annulus conductively connected to said thermocouple members at the hot junctions thereof and encircling the flame maintained by said burner to assure adequate heating of the hot junctions of the thermocouple when the flame is diverted by drafts.

3. In combination, a burner for maintaining a flame, a fuel supply pipe leading to said burner, an electromagnet having a magnet frame and a winding, a thermocouple comprising a pair of thermocouple members joined to form a thermal junction in position to be heated by the flame, one of said thermocouple members being conductively connected to the fuel supply pipe for the burner'and through said fuel supply pipe to the winding of the electromagnet, means connecting the other thermocouple member to the electromagnet winding, said thermocouple members being joined to form a hot junction at the edge of the flame maintained by said burner, and an annulus conductively connected to said thermocouple members at the hot junction thereof and encircling the flame maintained by said burner to assure adequate heating of the hot junction of the thermocouple when the flame is diverted by drafts.

'4. In combination, a burner for maintaining a flame, a fuel supply pipe leading to said burner, an electromagnet having a magnet frame and a winding, an annulus telescopically fitting over the burner and in conductive contact therewith, a conducting member surrounding saidannulus and insulated therefrom, a thermocouple comprising a pair of thermocouple members joined to form a thermal junction in position to be heated by said flame, one of said thermocouple members being conductively connected to said annulus and to the winding of the electromagnet through said annulus, the burner and the fuel supply pipe therefor, and the other thermocouple member being conductively connected to the conducting member surrounding said annulus and through said conducting member to the winding of the electromagnet.

5; In combination, a, burner for maintaining a flame, a fuel supply pipe leading to said burner, an electromagnet having a magnet frame and a winding, an annulus telescopically fitting over the burnerand in conductive contact therewith, a conducting member surrounding said annulus and insulated therefrom, a thermocouple comprising a pair of thermocouple members joined to form a thermal junction in position'to be heated by said flame, one of said thermocouple members being conductively connected to said annulus and to the winding of the electromagnet through said annulus, the burner andthe fuel supply pipe therefor, the other thermocouple member being conductively connected to the conducting member surrounding said annulus and through said conducting member to the winding of the electromagnet, and a second annulus conductively connected to said thermocouple member at the hot junction thereof and encircling the flame maintained by said burner to assure adequate heating of the hot junction of the thermocouple when the flame is diverted by drafts.

6. A self-contained thermocouple and pilot burner unit comprising a plurality of circumferentially spaced thermocouples, each comprising a pair of thermocouple elements joined at their outer ends to form a plurality of circumferentially disposed thermal junctions, a jet member joined to said thermocouples to form a unitary device having the desired relation between said jet member and the thermal junctions at the outer ends of said thermocouples, said jet member extending substantially axially between said circumferentially disposed thermocouples and having port means at its outer end through which fuel is discharged to maintaina pilot flame for use as an igniter, and shield means constituting a unitary part of the device and cooperating with the pilot flameto assure heating of all of the thermal junctions at the outer ends of said thermocouples.

'7. A thermocouple and pilot burner unit comprising a jetmember having port means through which fuel is discharged to maintain a pilot flame, a. fuel supply pipe connected to said jet member, a plurality of thermocouples disposed at circumferentially spaced locations about said jet member, each of said thermocouples comprising a pair of thermocouple elements joined at their outer ends to form a plurality of circumferentially disposed thermal junctions adapted to be heated by the pilot flame, insulating means surrounding said jet member and insulating the thermocouple elements of each thermocouple from each other and at least one thermocouple element of each thermocouple from said jet member, and means for clamping said thermocouples and insulating means in place upon said jet member so that the parts constitute a unitary device with the plurality of thermal junctions adapted to be heatedby the pilot flame .maintained in substantially corresponding rela-' flame, a fuel supplypipe connected to said jet .at circumferentially spaced locations about said jet member, each of said thermocouples comprising a pair of thermocouple elements joined at their outer ends to form a plurality of circumferentially disposed thermal junctions adapted to be heated by thepilot flame, insulating means surrounding saidjet member and insulating the thermocouple elements of each thermocouple from each other and at least one thermocouple element of each thermocouple from said jet member, means for clamping said thermocouples and insulating means in place upon said jet member so that the partsconstitute a unitary device with the plurality of thermal junctions adapted to be heated by the pilot flame maintained in substantially corresponding relation to said flame at circumferentially spaced positions by the clamping of said thermocouples and insulating means in place upon said jet member, and shield means constituting a unitary part of said device and cooperating with the pilot flame to assure heating of all of the thermal junctions iii at the outer ends of said thermocouples.

9. A thermocouple and pilot burner comprising a jet member having port means at its outer end through which iuel is discharged to maintain a pilot flame, a fuel supply pipe connected to said jet member, sleeve means surrounding said jet member and mounted thereon, and a plurality of thermocouples carried by said sleeve means and disposed at circumiepentially spaced aiaaaao couple elements joined at their outer ends to iorm a plurality 'oi circumferentially disposed thermaljunctions adapted to be heated by the pilot flame; the thermocouple elements of each thermocouple being insulated from each other and at least one thermocouple element of each thermocouple being insulated from said jet member.

10. A thermocouple and pilot burner comprising a jet member having port means at its outer end through which iuel is discharged to maintain a pilot flame. a fuel supply pipe connected to said jet member, sleeve means surrounding thermocouple being insulated from said jet memher, and shield means carried by said jet memher and constituting a unitary part of said device, said shield means cooperating with the pilot flame to confine same and assure heating of all oi the circumierentially disposed thermal junctions at the outer ends of said thermocouples.

GUHJO WflNSCH.

JOSE!" SCHUPPERT.

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