WO2005111500A2 - Systeme pour fixer des bougies d'allumage de chaudieres ou analogue - Google Patents

Systeme pour fixer des bougies d'allumage de chaudieres ou analogue Download PDF

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Publication number
WO2005111500A2
WO2005111500A2 PCT/EP2005/052146 EP2005052146W WO2005111500A2 WO 2005111500 A2 WO2005111500 A2 WO 2005111500A2 EP 2005052146 W EP2005052146 W EP 2005052146W WO 2005111500 A2 WO2005111500 A2 WO 2005111500A2
Authority
WO
WIPO (PCT)
Prior art keywords
ring
retainer
recess
extension
tightening
Prior art date
Application number
PCT/EP2005/052146
Other languages
English (en)
Other versions
WO2005111500A3 (fr
Inventor
Giorgio Offredi
Original Assignee
Castfutura S.P.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Castfutura S.P.A. filed Critical Castfutura S.P.A.
Priority to US11/569,186 priority Critical patent/US20090297998A1/en
Priority to BRPI0510876-4A priority patent/BRPI0510876A/pt
Priority to MXPA06013486A priority patent/MXPA06013486A/es
Priority to EP05742857A priority patent/EP1747402A2/fr
Publication of WO2005111500A2 publication Critical patent/WO2005111500A2/fr
Publication of WO2005111500A3 publication Critical patent/WO2005111500A3/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23Q—IGNITION; EXTINGUISHING-DEVICES
    • F23Q3/00—Igniters using electrically-produced sparks
    • F23Q3/006—Details

Definitions

  • the present invention relates to a fastening system for spark plugs of boilers, burners, hot plates, or the like, comprising a fastening plate or retainer having an hole housing the ceramic body of the spark plug.
  • a fastening plate or retainer having an hole housing the ceramic body of the spark plug.
  • Many different kinds of retainers of the type above defined are known. Each one acts for keeping a spark plug in a predetermined position useful for generating ignition sparks for liquid or gaseous fuels .
  • another type of spark plug acts for indicating the presence of flame.
  • Said spark plugs generally comprise a coating ceramic member with an elongated shape, generally cylindrical, for heat and electric insulation wherein a metal conducting member is included projecting outside thereof on both ends.
  • the spark plug has to be firmly supported in a determinate position, particularly at a constant in time and predetermined distance from the ground member. Moreover, when condensing boilers have been introduced wherein the furnace is at pressure slightly higher than the atmospheric pressure, it has become essential to fasten the spark plug on the retainer such that a perfect pneumatic pressure tight occurs between the retainer and the ceramic insulator, that is between a side and Giorgio A. Karaghiosoff European Patent Attorney
  • Retainer type providing at the housing hole for the spark plug a cylindrical member with an axial extension greater than the retainer thickness, and a further cylindrical member as an axially open ring that is fitted on the ceramic body of the spark plug and axially forced inside the cylindrical member in order to obtain an inwards elastic deformation and to tighten the spark plug body, do not guarantee the pressure tight.
  • the drawback of the manufacturing of a shaped ceramic body is a positioning limit of the spark plug on the retainer.
  • the system with threaded spark plug body and fastening screw provides a long mounting and sometimes Giorgio A. Karaghiosoff European Patent Attorney
  • the present invention aims to overcome all the above drawbacks, and by simple and inexpensive means it allows to manufacture a fastening system of the type disclosed hereinbefore allowing a simple, fast, inexpensive and firm in time fastening of the spark plug on the retainer in a determinate position and with a perfect orthogonal arrangement with respect to the two faces of the retainer, using a very small amount of components. Moreover it is desired that fastening of the spark plug on the retainer is of the pressure tight type, such to allow the use even with condensating boilers.
  • the invention attains the above aims by means of a fastening system of the type described hereinbefore wherein the hole housing the spark plug axially projects for a certain length at least on one side of the retainer beyond the thickness thereof such to form a cylindrical housing for the ceramic body of the spark plug. It is further provided a cylindrical tightening ring having such inner and external radial dimensions that it can be inserted by force fit between the inner Giorgio A. Karaghiosoff European Patent Attorney
  • the retainer and the ring are made of metal material in order to guarantee a positioning firmness in time of the spark plug. While any metal materials can be used, metal materials having a good thermal resistance are preferred, in the sense of wear thereof due to thermal stress. Metal materials of the retainer and the ring can be the same or different one with respect to the other. In the case of different metal materials it is advantageous to provide two metal materials whose difference in thermoelectric potential is negligible.
  • the locking fit provides that during the pressure force fit of the ring between the inner edge of the hole housing the spark plug and the external wall of the spark plug, a partial deformation is obtained in the sense of an expansion of the housing hole in the retainer and a partial deformation in the sense of a radial compression of the ring.
  • the relation between the deformation of the retainer hole in the sense of an expansion thereof and of the ring in the sense of a compression thereof Giorgio A. Karaghiosoff European Patent Attorney
  • the inside diameter of the hole housing the spark plug has a such size with respect to the external diameter of the spark plug that the difference in diameter is slightly less than the ring thickness.
  • the ring particularly is a member for compensating and recovering the tightening radial pressure that eventually exceeds a predetermined pressure value for properly tightening the spark plug inside the cylindrical housing of the retainer and such to avoid the breaking or the cracking of the ceramic body.
  • the latter has a conical thinning or tapering allowing the entry between inner edge of the hole and external surface of the spark plug in a position for the axial force fit compression in the final position locking the spark plug in the retainer hole.
  • the fact that the ring and the retainer are made of brass has the advantage to provide the two parts made of a quite ductile metal.
  • brass has a low resistance to thermal stress and moreover particularly the ring has to be made with forming techniques, that is quite expensive.
  • the fastening of the spark plug is made in a proper way.
  • the fact of manufacturing the ring with brass and the retainer with a different material such as steel, stainless steel, or the like allows to manufacture at Giorgio A. Karaghiosoff European Patent Attorney
  • the retainer with a less expensive material and that can be processed or molded by shearing.
  • the obtained fastening is also a good one.
  • the combination of the two different materials leads to a thermoelectric potential that cannot be absolutely ignored and to the arise of deterioration cases due to said difference in potential.
  • said means can be an annular widening of one of the two circular head edges of the cylindrical tightening ring constituting an abutment annular flange stopping the insertion of the tightening ring inside the cylindrical housing of the retainer.
  • the circular head end of the tightening ring faced to the one having the annular flange may have a beveled or rounded external edge for facilitating the insertion of the tightening ring inside the cylindrical housing of the retainer.
  • a second type of the fastening system according to the present invention provides both for the retainer and the ring to use metal materials having a good resistance to thermal stress and generating a negligible difference in thermoelectric potential one with respect to the other at the same time constituting a low cost metal and easy to work particularly by shearing. Particularly it is advantageous to manufacture both the retainer and the ring with steel or stainless steel.
  • thermoelectric potential is not generated whose micro currents can cause oxidation and corrosion cases in time. If ceramic has through cracks, it is possible to have also micro currents cases generated by retainer- ring and electrode members with respect to the ground, that in the case of electrodes detecting the flame, can be considered as current of present flame signal even when the flame burns out with the valve controlling the gas flow supplying the burner going on in the open condition. In this case unburnt gas can came out from the boiler that can cause dangerous explosions. In the simple case of an ignition electrode, the latter could not properly work. Giorgio A. Karaghiosoff European Patent Attorney
  • the present invention overcomes the drawback disclosed above by means of a retainer of the type described hereinbefore wherein even in this case the housing hole axially projects for a certain length at least on one side of the retainer beyond the thickness thereof such to form a cylindrical housing for the ceramic body of the spark plug, but the tightening ring is made of a material, particularly metal, with a low ductility or deformation capacity, particularly it is made of the same material as the retainer, particularly steel, stainless steel or the like. Steel, and particularly stainless steel have an optimum resistance to thermal stresses and are material relatively inexpensive. Moreover, they allow the manufacture of constructive parts by simply shearing thereof from a continuous sheet, thereby the manufacturing cost of the finished part is generally very low, and manufacturing processes are of high efficiency.
  • the ring may be shaped such to have one or more areas for compensating and recovering the tightening radial pressure that eventually exceeds a predetermined pressure value that can be supported by the ceramic. More specifically, the tightening ring may have one or more openings for the release and recovering of the radial deformation of the ring when the spark plug is tightened inside the cylindrical housing of the retainer.
  • the tightening ring may have at least one, preferably a plurality of notches originating from the two opposite head circular edges of the ring and extending only for a portion of the axial extension of the ring, such to guarantee the pressure tight by the ring itself.
  • Said notches may have all the same lengthways extension.
  • Particularly said extension may be comprised between about a third and about an half of the axial extension of the ring.
  • Particularly and advantageously notches have such an axial length to delimit an intermediate continuous annular band of the ring having a very small axial size and such that it can be easily deformed.
  • such intermediate continuous annular band has an axial size of some millimeters and more precisely from 1 to 3 mm.
  • Said notches can be arranged with alternate positions one with respect to the other, that is each notch can originate from an head circular edge of the tightening ring opposite to the head circular edge from which the immediately next notch originates.
  • This embodiment allows to compensate the low ductility and the low compressibility of the ring material and at the same time it guarantees the proper seal since it generates no axial continuous through slot.
  • the tightening ring at the intermediate annular band may have at least an opening or slot for the release or recover of the radial narrowing occurring in said intermediate annular Giorgio A. Karaghiosoff European Patent Attorney
  • said slot may be sickle-shaped with the two ends arranged along an axis parallel to the central axis of the tightening ring, and it may extend at a central annular band corresponding to notch end portions arranged at the closed ends thereof.
  • the tightening ring may be manufactured as an open one, while maintaining the pressure tight between one side and the other side of the retainer.
  • the ring at two faced head edges of a strip that is bent and closed on itself in a cylindrical shape has an hooking recess that narrows as regards its dimension in the axial direction of the ring at the corresponding head edge of the strip forming the ring and which hooking recess cooperates with a hooking extension that has a shape that is complementary to the hooking recess and it has a material portion for the connection to the corresponding head side of the bent strip forming the ring with an axial size smaller than the remaining part of said hooking extension.
  • Said hooking recess and the cooperating hooking extension are complementary means for the reciprocal fastening of faced head sides of the bent strip, that is means for closing the ring.
  • the recess and extension closing the tightening ring may be provided in substantially intermediate positions of respective straight portions of head sides of the strip forming the ring, with which straight Giorgio A. Karaghiosoff European Patent Attorney
  • the extension closing the tightening ring may have a root with a narrow shape projecting in the substantially circumferential direction of the ring with a substantially circular shape widened part, while the corresponding recess placed on the opposite end of the tightening ring may have a shape substantially complementary to the one of said extension.
  • the hooking recess and the corresponding hooking extension of the tightening ring have complementary shapes but the hooking recess has sizes slightly smaller than the hooking extension ones and they can be secured one inside the other by force fit, causing a firm closing of the ring.
  • one or both head circular edges of the ring may have an entrance beveling in order to facilitate the insertion by force fit of the ring inside the cylindrical housing. Due to the arrangements considered in said second embodiment of the invention, if required, it is possible to manufacture the ring with the same material as the retainer guaranteeing both the possibility to recover the tightening radial deformation and the pressure tight between one side and the other side of the retainer. All this is due to the fact that axial notches are not through notches and hooking means of the two faced head sides of the bent strip forming the ring engaging by force fit avoid the leak of gas . Giorgio A. Karaghiosoff European Patent Attorney
  • the ring is easy to manufacture, for example by means of shearing, and subsequent closing on itself.
  • the closing by forcing hooking means on head sides of the strip forming the ring makes it more strong and resistant when it is compressed inside the retainer and it do not require a heat treatment to make it enough strong.
  • a saving in heat treatment cost and in costs due to logistics is obtained since the process is not carried out by the supplier of the part, a vacuum furnace being required.
  • the constructive manufacturing of the ring by means of a metal material strip that is sheared from a continuous metal material sheet allows to work with a quick and inexpensive manufacturing method and allowing to obtain considerable per ormances .
  • the dimensional interference between the hooking recess and the hooking extension is automatically obtained by means of the shearing operation allowing to form the hooking extension of a preceding material strip with the part removed for making the hooking recess of the immediately subsequent material strip. All this is due to the fact that the shearing of the sheet generally causes the cutting of the material for about a third of its thickness, while the remaining two thirds of the material thickness is broken and therefore deformed generating small dimensional differences between hooking recess and hooking extension leading to a reciprocal engagement by force fit.
  • FIG. 1 is a perspective view of an spark plug being secured on a retainer according to the present invention by means of a first tightening ring embodiment.
  • Fig. 2 is an exploded view of the assembly of fig. 1.
  • Fig. 3 is a perspective view of the first tightening ring embodiment.
  • - Fig. is a side view of assembly of fig. 1, in Giorgio A. Karaghiosoff European Patent Attorney
  • FIG. 5 is a top plant view of assembly of fig. 1.
  • - Fig. 6 is a perspective view of a spark plug being secured on a retainer according to the present invention by means of a second tightening ring embodiment.
  • Fig. 7 is an exploded view of assembly of fig. 6.
  • Fig. 8 is a perspective view of the second tightening ring embodiment.
  • Fig. 9 is a part section side view, of the second tightening ring embodiment.
  • - Fig 10 is a plant view of the second tightening ring embodiment in the expanded condition.
  • Fig. 11 is a perspective view of a variant of the tightening ring according to figures 8 to 10.
  • Fig. 5 is a top plant view of assembly of fig. 1.
  • - Fig. 6 is a perspective view of a spark plug being secured on a retainer according to the present invention by means of a second tightening ring embodiment.
  • Fig. 7 is an exploded view of assembly of fig
  • FIG. 12 is an axial sectional view of an embodiment of a retainer.
  • Fig. 13 is a perspective exploded view of the fastening plate, the cylindrical ceramic body of the spark plug and the tightening ring, wherein the ring is made according to the embodiment of figures 1 to 5 while the fastening plate is made according to the embodiment of figure 12.
  • Figure 14 is a perspective axial section of the fastening plate, the cylindrical ceramic body of the spark plug and the tightening ring according to figure 13 in the mounted condition.
  • Figure 15 is a perspective view of a further embodiment of the retainer.
  • the retainer 1 comprises a substantially flat annular plate-like part connecting to a remaining part of retainer 1 , which has a hole 2 for the passage of a screw fastening the retainer 1 on the boiler.
  • the retainer 1 is completely flat, but it can be fabricated in any shape with respect to the device to which it has to be matched.
  • the retainer 1 further comprises an hole for housing the spark plug 4 , which hole has a complementary shape with respect to the external section of the spark plug 4 that generally is fabricated with a cylindrical shape.
  • the spark plug 4 is composed of a cylindrical ceramic body 104 provided with an axial hole 404 inside which there is provided a metal electrode 204 provided with an annular widening 304 stopping the insertion of the electrode 204 inside the hole 404 of the ceramic body 104. With the electrode 204 being fastened inside the hole 404 of the ceramic body 104, said electrode 204 projects to a predetermined extent from both ends thereof.
  • a projecting end has a shape such that it can be connected to an electric conductor for example by means of a Faston type connector or the like, while the opposite end projects from the ceramic body 104 to a greater extent and, in the shown embodiment, it is angularly bent such that, with the spark plug 4 applied on the boiler, it is at a predetermined distance from the ground member for generating the ignition spark.
  • the present invention is shown in combination with a spark plug 4 , it is to be noted that it can be advantageously applied even to fastening of spark plugs detecting the presence of flame, or the like.
  • the cylindrical hole for housing the spark plug 4 axially extends for a certain length on a side of the retainer 1 beyond the thickness thereof towards the ignition end of the spark plug 4 such to realize a cylindrical housing 5 for the ceramic body 104 of the spark plug 4.
  • the cylindrical housing 5 it is possible to provide for the cylindrical housing 5 to be faced in the opposite direction or both directions.
  • the inside diameter of the cylindrical housing 5 is greater than the external diameter of the ceramic body 104, a first embodiment of cylindrical tightening ring 6 being provided having such inside and external radial dimensions that it can be inserted by force fit between the inside wall of the cylindrical housing 5 of the retainer 1 and the external wall of the ceramic body 104 of the spark plug 4 such to provide a predetermined radial tightening force of the spark plug 4 inside the cylindrical housing 5 of the retainer 1 and such to have a tight seal between one side and the other side of the retainer 1.
  • the pressure tight between the combustion environment and the external environment can be further guaranteed by the presence of a wall 7 dividing said two environments that is provided inside the boiler.
  • the retainer 1 is generally entirely made of a material that is substantially not Giorgio A. Karaghiosoff European Patent Attorney
  • the tightening ring 6 is made of a material having predetermined deformation and ductility characteristics, particularly metal. According to a preferred embodiment, the tightening ring 6 is made of brass. When the ring 6 is inserted by force fit in the space comprises between the inner wall of the cylindrical housing 5 and the external wall of the ceramic body 104 of the spark plug 4, the ring 6 suffers a slight deformation tightening the ceramic body 104 and firmly secures in position the spark plug 4 on the retainer 1.
  • the ductility of brass compensates and recovers the tightening radial pressure that eventually exceeds a predetermined pressure value for proper tightening the spark plug 4 inside the cylindrical housing 5 of the retainer 1 and it avoids the possible breaking of ceramic.
  • Even the retainer suffers a partial deformation relevant to the expansion of the hole housing the spark plug that in this case is less than the deformation of the ring due to the relation between the brass and steel deformation. Due to the fact that the cylindrical housing 5 has a certain axial extension and it is perpendicular to the surface of retainer 1 , the perfect orthogonality is guaranteed between the spark plug 4 and the surface of retainer 1, while the presence of the ring 6 with a continuous cylindrical extension guarantees the pressure tight between a side and the other side of the retainer 1. In order to facilitate the insertion of the tightening ring 6 inside the Giorgio A. Karaghiosoff European Patent Attorney
  • the circular edge of the cylindrical housing 5 that is coplanar to one of the two faces of the retainer 1 has an entrance flare 105.
  • one of the two circular head edges of the cylindrical tightening ring 6 has an abutment annular flange stopping the insertion of the tightening ring 6 inside the cylindrical housing 5 of the retainer 1.
  • the opposite circular head end of the tightening ring 6 has a beveled or rounded edge 206 for facilitating the insertion of the tightening ring 6 inside the cylindrical housing 5 of the retainer 1.
  • a second system for fastening the spark plug 4 on the retainer 1 is shown based on a second tightening ring embodiment 8 that in this case is made of the same material as the retainer 1, generally steel, in order to satisfy particular situations wherein the presence of two different metals, that of the ring 6 and that of the retainer 1, can cause the above drawbacks, such as eddy current or the like.
  • the spark plug 4 is secured on the retainer 1 introducing by force fit the tightening ring 8 between the inner wall of the cylindrical housing 5 and the external wall of the ceramic body 104 of the spark plug 4.
  • the tightening ring 8 since the tightening ring 8 is made of a material that substantially is not much capable of being deformed or having a greater resistance to deformation, it has a plurality of notches 108 originating from two opposite circular head edges of the ring 8 and extending between about a third and Giorgio A. Karaghiosoff European Patent Attorney
  • each notch 108 originates from a circular head edge of the tightening ring 8 opposite to the circular head edge from which the immediately adjacent notch 108 originates and a continuous intermediate annular band is formed there between having a very little size in the axial direction of the ring particularly between 1 and 3 mm. It is also possible that no continuous intermediate annular band is formed, when notches have an extension in the axial direction of the ring that is half of the total axial extension of the ring.
  • the tightening ring 8 is manufactured by shearing and rolling it in a cylindrical shape a strip of metal material and therefore it is substantially an open ring with an opening cut that is rectilinear and parallel to the central axis of the ring 8. Both for allowing the closure of the ring, that is the connection of the two faced head edges of the material strip and for guarantee the pressure tight by the ring 8 between a Giorgio A. Karaghiosoff European Patent Attorney
  • an head side on one end of the material strip forming the tightening ring 8 placed at the opening cut has a recess 208, while the head side of the opposite end has an extension 308 intended for the engagement in said recess 208 for closing the tightening ring 8.
  • the recess 208 and the extension 308 closing the tightening ring 8 are provided in positions that are substantially intermediate in the respective straight portions of head sides of ends of the ring 8, and said recess 208 and said extension 308 connect in a rounded way with said straight portions.
  • the extension 308 closing the tightening ring 8 has a root 408 of narrow shape extending in the substantially circumferential direction of the ring 8 with a widened portion of substantially circular shape, while the corresponding recess 208 placed on the opposite end of the tightening ring 8 has a shape that is substantially complementary to the one of said extension 308.
  • the size of the extension 308 is slightly greater than that of the hooking recess 208. Due to this arrangement, the extension 308 engages by force fit the recess 208, making a firm mechanical connection of the two faced head ends of the strip forming the ring and generating a seal adhesion of perimetral edges of the hooking recess with the hooking extension.
  • the arrangement above disclosed regarding the hooking member and the recess with widened head and the rounded shape facilitates the generation of contact areas between the recess edge and the extension edge Giorgio A. Karaghiosoff European Patent Attorney
  • the fastening system allows to have gas tight conditions need for the use in condensing boilers even if the ring is a substantially open ring.
  • the manufacturing of the open ring allows in turn the manufacturing thereof by shearing the material strip from a continuous material band.
  • the facing ends of the open ring have respectively a protrusion 308' and a recess 208' which have a constant axial width.
  • protrusion 308' and of the recess 208' which are oriented in the circumferential direction of the ring can slide one against the other.
  • the axial width of the protrusion and of the recess are identical within the limits of high tolerances so that a sealing effect is achieved when the protrusion is fit inside the recess, and in any case at least when the deformation of the ring has occurred after having forced it together with the ceramic body of the spark plug in the retainer bushing.
  • the protrusion which is arched correspondingly to the radius of the ring does not completely fit inside the recess but it is in a position with it end at a certain distance of the axial bottom edge of the recess.
  • the depth of the recess and the length of the protrusion are such that between the axial edges of the protrusion and of the recess and the resting facing axial surfaces of the ring on both sides of the protrusion and of the recess a certain distance is maintained helping in allowing to receive the expansion of the material of the ring when it is compressed between the ceramic body and the cylindrical seat 5 of the retainer 1 in order to avoid excessive radial forces on the ceramic body.
  • the tightening ring according to this variant and in the rolled condition of the metal strip forming the ring has an axial cut forming two facing ends .
  • the axial cut has a certain width so that Giorgio A. Karaghiosoff European Patent Attorney
  • a first end has a central protrusion 308' and the opposite end has a recess 208' coinciding with the said central protrusion.
  • the central protrusion is curved essentially with the same radius as the ring and has circumferential side edges extending along a plane perpendicular to the ring axis .
  • the recess has circumferential side edges extending along the same plane perpendicular to the ring axis as the side edges of the said central protrusion 308' .
  • the axial width of the central protrusion and the axial width of the recess are almost identical such that the protrusion fits in the said recess with the side edges of the said central protrusion coming into contact with the corresponding side edges of the recess .
  • the said recess has an angular extension which corresponds essentially to the width of the axial cut.
  • the axial width of the protrusion of one end of the tightening ring and the axial width of the recess are such that the side edges of the protrusion and the corresponding side edges of the recess extending in circumferential direction of the ring adheres one to the other in a sealing way, at least after being forced together with the ceramic body of the spark plug (4) in the retainer.
  • the axial dimension of the protrusion 308' and of the cooperating recess 208' are less than the total axial extension of the ring and the said protrusion and the said recess are almost centered relatively to the said total axial extension of the ring. So at both Giorgio A. Karaghiosoff European Patent Attorney
  • the ring has also the axial notches 108' as in the embodiment according to figures 6 to 10. Relating to the method for building the ring according to the embodiment of figure 11, the same method as described for the ring according to figures 6 to 10 can be used. It has to be noted that during force fitting of the tightening ring inside the retainer 1 together with the ceramic body of the spark plug 4 positioned inside the tightening ring, the radial compression of the tightening ring can be partly compensated by a circumferential sliding of the protrusion 308' inside the recess 208' .
  • FIG. 12 illustrate an embodiment of the retainer 1.
  • the cylindrical seat 5 for the ring and for the ceramic body of the spark plug 4 has a first entrance flare 105 at the circular edge of the cylindrical housing 5 that is coplanar to one of the two faces of the retainer 1 as described with Giorgio A. Karaghiosoff European Patent Attorney
  • a frustoconical part 205 reduces further the internal diameter of the cylindrical seat to the end diameter of the cylindrical seat formed by a cylindrical bushing 305.
  • the thickness of the fastening plate is bigger than the thickness of the walls of the cylindrical bushing or extension 5 forming the seat for the ceramic body of the park plug 4 and of the tightening ring 8.
  • the above internal shape of the seat allows to maintain the diameter of the hole passing the fastening plate 101 with a diameter slightly larger.
  • the bushing itself, or at least the cylindrical seat 5 has a reduced thickness of the walls, particularly for the part having the final correct diameter for press fitting the tightening ring and the ceramic body of the spark plug 4. This allows that radial forces can be at least partially absorbed by a deformation not only of the tightening ring but also of the cylindrical seat 5, i.e. of the terminal cylindrical extension 305.
  • An increased thickness of the fastening plate 101 of the retainer is very helpful since during securing of the plate by means of screws passing through holes Giorgio A. Karaghiosoff European Patent Attorney
  • the fastening plate could arcuate or bend or be submitted to other deformations when the screws are tightened. This is particularly relevant not only for the correct positioning of the spark plug 4 relatively for example to a burner, but also in connection with gas tight combustion chambers, since a deformation of the fastening plate could lead to leakage .
  • the retainer can be built in a simple manner by drawing or pressing since the material which has to be eliminated for forming the hole in the fastening plate for the spark plug is sufficient to form the seat 5 with a reduced wall thickness .
  • Figures 13 and 14 illustrates the ceramic body of the spark plug 4 and the tightening ring 6 according to the embodiment of figures 1 to 5 in combination with a retainer accoding to figure 12 and respectively in the non mounted condition and in the condition in which the ceramic body of the spark plug 4 with the tightening ring 6 are forced inside the retainer 1.
  • the retainer according to figure 12 can be used in combination with every one of the embodiments of the rings 6 or 8 described above.
  • Relating to the thickness of the fastening plate and of the walls of the cylindrical seat 5 good results has been obtained with a fastening plate having a thickness of at least 3mm, while the walls of the cylindrical seat 5 has a thickness of less than 2mm.
  • the fastening plate has a thickness from about 3mm to about 5mm, while the walls of the Giorgio A.
  • cylindrical seat 5 has a thickness of about 1mm to 2mm.
  • Analogous results in stiffening the fastening plate relatively to deformation at the fastening of the said plate can be obtained with a retainer according to the embodiments of figures 1 to 10 by providing the fastening plate of the retainer with stiffening ribs.
  • Figure 15 illustrates such a stiffened fastening plate 101 which in this embodiment is provided with a peripheral rib 301.
  • the thickness of the plate 101 is less than 3mm according to the plate 101 of the embodiment of figures 1 to 10 and the stiffening rib is obtained by deformation of the peripheral edge of the plate 101 by means of stamping or drawing.
  • a further feature which appears in the embodiment of figure 15 and which can be provided for each of the different embodiments of the fastening plate 101 of the retainer 1 consist in a mean for connecting electrically and mechanically a conductor, particularly a cable for generating an electrical connection to earth potential.
  • the mean for connecting electrically and mechanically a conductor consist in a shaped protrusion forming the male of female part of a electrical and/or mechanical connector which other respectively female or male part is fastened to the end of the cable.
  • the mean for connecting electrically and mechanically a conductor consist in a shaped protrusion, such as a metallic tongue 401 which is dimensioned and shaped in such a way as to cooperate with the female part of a so called FASTOM® connector.
  • the tongue is made in one piece with the retainer and it is obtained together with the other features of the retainer in a one shot operation of stamping or drawing from a metallic sheet.
  • the retainer can be made of any kind of metal, particularly of brass, copper, copper-nickel alloy, steel .
  • the cylindrical seat 5; 305 with the reduced diameter for force fitting the said ceramic body and the tightening ring eventuall y together with the said frustoconical part 205 have an axial extension corresponding at least to the axial extension of the tightening ring.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Spark Plugs (AREA)

Abstract

La présente invention concerne un système pour fixer des bougies d'allumage (4) destinées à des chaudières ou analogue, comprenant un élément de retenue (1) destiné à la fixation de bougies d'allumage (4) de chaudières, un orifice contenant le corps céramique (104) de la bougie d'allumage (4), ledit orifice se projetant axialement sur une certaine longueur au moins sur un côté de l'élément de retenue (1) de façon à former un boîtier cylindrique (5) pour le corps céramique (104) de la bougie d'allumage (4); un anneau de serrage cylindrique (6, 8) ayant des dimensions extérieures et intérieures qui lui permettent d'être inséré par ajustement serré entre la paroi intérieure du boîtier cylindrique (5), et la paroi extérieure du corps céramique (104), de façon à produire une force de serrage radiale prédéterminée sur la bougie d'allumage (4), et à obtenir un joint étanche entre un côté et l'autre de l'élément de retenue (1). Dans un premier mode de réalisation, l'anneau (6) est fait d'un métal ayant des propriétés de ductilité et de capacité de déformation prédéterminées. Dans un second mode de réalisation, l'anneau (8) est fait d'un métal ayant une capacité de déformation faible, et présente une pluralité d'ouvertures (108, 9) qui servent à relâcher la déformation radiale de l'anneau (8) lorsque la bougie d'allumage (4) est serrée à l'intérieur du boîtier cylindrique (5).
PCT/EP2005/052146 2004-05-17 2005-05-11 Systeme pour fixer des bougies d'allumage de chaudieres ou analogue WO2005111500A2 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US11/569,186 US20090297998A1 (en) 2004-05-17 2005-05-11 System for fastening spark plugs of boilers or the like
BRPI0510876-4A BRPI0510876A (pt) 2004-05-17 2005-05-11 sistema de aperto de velas de ignição para caldeiras e/ou similares
MXPA06013486A MXPA06013486A (es) 2004-05-17 2005-05-11 Sistema para sujetar bujias de calderas o similares.
EP05742857A EP1747402A2 (fr) 2004-05-17 2005-05-11 Systeme pour fixer des bougies d'allumage de chaudieres ou analogue

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT000022A ITSV20040022A1 (it) 2004-05-17 2004-05-17 Sistema di fissaggio per candele d'accensione di caldaie o simili
ITSV2004A000022 2004-05-17

Publications (2)

Publication Number Publication Date
WO2005111500A2 true WO2005111500A2 (fr) 2005-11-24
WO2005111500A3 WO2005111500A3 (fr) 2006-06-01

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2005/052146 WO2005111500A2 (fr) 2004-05-17 2005-05-11 Systeme pour fixer des bougies d'allumage de chaudieres ou analogue

Country Status (7)

Country Link
US (1) US20090297998A1 (fr)
EP (1) EP1747402A2 (fr)
BR (1) BRPI0510876A (fr)
IT (1) ITSV20040022A1 (fr)
MX (1) MXPA06013486A (fr)
RU (1) RU2006140467A (fr)
WO (1) WO2005111500A2 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITGE20090002A1 (it) * 2009-01-21 2010-07-22 Castfutura Spa Sistema di fissaggio per candele d'accensione di caldaie o simili
ITPD20100234A1 (it) * 2010-07-22 2012-01-23 Athena S P A Metodo di produzione per produrre un complesso di supporto per supportare un elettrodo di attivazione di un dispositivo di accensione per un apparato di combustione, complesso di supporto cosi' ottenibile, nonche' dispositivo di accensione e apparato
US8175196B2 (en) 2006-03-02 2012-05-08 Lg Electronics Inc. Channel equalizer and method of processing broadcast signal in receiving system

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITVA20100010U1 (it) * 2010-03-25 2011-09-26 Whirlpool Co Sistema di fissaggio per un elettrodo di accensione di un bruciatore a gas.
WO2015198211A1 (fr) * 2014-06-26 2015-12-30 Castfutura S.P.A. Système et procédé pour fixer des bougies de détection et/ou d'allumage et/ou un hublot d'inspection de chaudières ou analogues
US9450330B2 (en) * 2014-06-30 2016-09-20 Agilent Technologies, Inc. Connector assembly for an inductively coupled plasma source
DE102018123097B4 (de) * 2018-09-20 2021-12-16 Anton Paar Provetec Gmbh Elektrozündung für Flammpunkttester

Citations (7)

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Publication number Priority date Publication date Assignee Title
CH452462A (de) * 1965-01-27 1968-05-31 Junkers & Co Vorrichtung zum Anzünden und Überwachen von gasbeheizten Geräten
GB1227840A (fr) * 1967-11-25 1971-04-07
DE9415187U1 (de) * 1993-09-16 1994-11-03 Vaillant Joh Gmbh & Co Durchführung
EP0930464A2 (fr) * 1998-01-20 1999-07-21 Rauschert GmbH & Co. KG Méthode et système d'assemblage étanche d'une électrode de brûleur
US6059479A (en) * 1998-03-13 2000-05-09 Ensign Ribbon Burners, Llc Pop-out electrode assembly
FR2834049A1 (fr) * 2001-08-06 2003-06-27 Sapco Bougie d'allumage pour bruleur a gaz ou a mazout avec protection contre la corrosion
FR2834048A1 (fr) * 2001-08-06 2003-06-27 Sapco Bougies d'allumage pour bruleur a gaz ou a mazout avec protection contre la corrosion

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH452462A (de) * 1965-01-27 1968-05-31 Junkers & Co Vorrichtung zum Anzünden und Überwachen von gasbeheizten Geräten
GB1227840A (fr) * 1967-11-25 1971-04-07
DE9415187U1 (de) * 1993-09-16 1994-11-03 Vaillant Joh Gmbh & Co Durchführung
EP0930464A2 (fr) * 1998-01-20 1999-07-21 Rauschert GmbH & Co. KG Méthode et système d'assemblage étanche d'une électrode de brûleur
US6059479A (en) * 1998-03-13 2000-05-09 Ensign Ribbon Burners, Llc Pop-out electrode assembly
FR2834049A1 (fr) * 2001-08-06 2003-06-27 Sapco Bougie d'allumage pour bruleur a gaz ou a mazout avec protection contre la corrosion
FR2834048A1 (fr) * 2001-08-06 2003-06-27 Sapco Bougies d'allumage pour bruleur a gaz ou a mazout avec protection contre la corrosion

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8175196B2 (en) 2006-03-02 2012-05-08 Lg Electronics Inc. Channel equalizer and method of processing broadcast signal in receiving system
ITGE20090002A1 (it) * 2009-01-21 2010-07-22 Castfutura Spa Sistema di fissaggio per candele d'accensione di caldaie o simili
EP2211103A1 (fr) * 2009-01-21 2010-07-28 Castfutura S.p.A. Système pour fixer des bougies d'allumage de chaudières ou analogue
ITPD20100234A1 (it) * 2010-07-22 2012-01-23 Athena S P A Metodo di produzione per produrre un complesso di supporto per supportare un elettrodo di attivazione di un dispositivo di accensione per un apparato di combustione, complesso di supporto cosi' ottenibile, nonche' dispositivo di accensione e apparato

Also Published As

Publication number Publication date
EP1747402A2 (fr) 2007-01-31
BRPI0510876A (pt) 2007-11-27
MXPA06013486A (es) 2007-06-12
WO2005111500A3 (fr) 2006-06-01
RU2006140467A (ru) 2008-06-27
US20090297998A1 (en) 2009-12-03
ITSV20040022A1 (it) 2004-08-17

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