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Title:
THERMOCOUPLE CONNECTOR ADAPTED FOR THE CONNECTION WITH A SAFETY VALVE AND THERMOCOUPLE
Document Type and Number:
WIPO Patent Application WO/2021/048684
Kind Code:
A1
Abstract:
Thermocouple connector, which thermocouple comprises: a phase conductor and an earth conductor and which connector is adapted for the electrical connection to a gas safety valve, which safety valve has a phase terminal and an earth terminal, the connector comprising: a phase terminal connectable to the phase conductor of the thermocouple and connectable to the phase terminal of the safety valve, an earth terminal connectable to the earth conductor and to the earth terminal of the safety valve and an insulating body inside which the phase terminal of the connector is housed and outside said insulating body the earth terminal of said connector is provided, the insulating body further comprising a plurality of axial slits that generate a crown of axial fins separated from each other and extending from the engagement end of the connector with the safety valve for a certain axial length towards the opposite end of said connector. According to the invention, the earth terminal of the connector consists of a bushing open along an axial band and which bushing is shaped and made of electrically conductive material with elasticity that allows a radial widening of said bushing, while the wall of said bushing has elastically compressible bands angularly distributed along the circumference thereof, which bands consist of bands of material of said bushing, which are bent radially towards the outside so as to take an arc-shaped profile, radially outwards.

Inventors:
TABAKU EDMIR (IT)
CULATTI MARCO (IT)
COCOLIN MARCO (IT)
Application Number:
PCT/IB2020/058120
Publication Date:
March 18, 2021
Filing Date:
September 01, 2020
Export Citation:
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Assignee:
CASTFUTURA SPA (IT)
International Classes:
H01R13/17; F23N5/10; H01R4/64; H01R13/193; H01R24/38; H01R103/00
Foreign References:
EP2802042A12014-11-12
JPH11233184A1999-08-27
DE1928577U1965-12-09
NL6409887A1965-03-01
Attorney, Agent or Firm:
KARAGHIOSOFF, Giorgio A. (IT)
Download PDF:
Claims:
RIVENDICAZIONI

1. Thermocouple connector, which thermocouple comprises: a phase conductor and an earth conductor and which connector is adapted for the electrical connection to a gas safety valve, which safety valve has a phase terminal and an earth terminal, the connector comprising: a phase terminal connectable to the phase conductor of the thermocouple and connectable to the phase terminal of the safety valve, an earth terminal connectable to the earth conductor and to the earth terminal of the safety valve and an insulating body inside which the phase terminal of the connector is housed and outside said insulating body the earth terminal of said connector is provided, the insulating body further comprising a plurality of axial slits that generate a crown of axial fins separated from each other and extending from the engagement end of the connector with the safety valve for a certain axial length towards the opposite end of said connector,

Characterized in that the earth terminal of the connector consists of a bushing open along an axial band and which bushing is shaped and made of electrically conductive material with elasticity that allows a radial widening of said bushing, while the wall of said bushing has elastically compressible bands angularly distributed along the circumference thereof, which bands consist of bands of material of said bushing, which are bent radially towards the outside so as to take an arc-shaped profile, radially outwards.

2. Connector according to claim 1, wherein the angular extension of said bushing is between 180° and 300°.

3. Connector according to claims 1 or 2, wherein, at a band of said bushing opposite the opening area thereof, said band extends beyond a head side of the bushing, forming a fastening terminal for an earth conductor.

4. Connector according to one or more of the preceding claims, wherein said bushing is housed in a circumferential recess of corresponding shape, provided on the outer side of the insulating body.

5. Connector according to one or more of the preceding claims, wherein said circumferential recess has a diameter substantially corresponding the diameter of said bushing in rest condition, i.e. not elastically deformed.

6. Connector according to one or more of the preceding claims, wherein the insulating body extends for a predetermined extent beyond the head side of the circumferential recess for housing said bushing, said extension stretch being provided with a radial step-like widening at its end, which radial step-like widening is tapered conically to form a coupling guiding surface in the terminal of the safety valve.

7. Connector according to one or more of the preceding claims, wherein at least the length of the section projecting beyond one of the head sides of said earth terminal bushing is made of separate axial sectors due to through axial slits, which divide the wall of said section into wall sectors, said slits extending up to the head end of said protruding section.

8. Connector according to claim 7, wherein said slits extend also at least for part or for the entire axial length of the bushing and in the area of the circumferential recess.

9. Connector according to one or more of the preceding embodiments, wherein the phase terminal consists of a tubular element intended to be mechanically and interlockingly engaged in an axial hole of the insulating body, and which tubular element has an annular radial narrowing in an intermediate area of the axial extension.

10. Connector according to claim 9, wherein said tubular element is also made open along an axial band.

11. Connector according to one or more of the preceding claims, wherein, substantially at said radial, annular narrowing, said tubular element is made of a plurality of axial thin plates separated by axial slits, said thin plates connecting at their ends to the remaining part of the tubular element.

12. Connector according to claim 10 or 11, wherein the annular radial narrowing of said tubular element comprises an initial narrowing section and a final widening section, which sections are progressive and/or substantially conical.

13. Thermocouple comprising at least one phase conductor and at least one earth conductor, a connector connecting the thermocouple being provided to a safety valve, and which connector is provided with a phase connection terminal and an earth connection terminal to which the corresponding conductors are connected, while said connector has the characteristics according to one or more of preceding claims 1 to 12.

Description:
"THERMOCOUPLE CONNECTOR ADAPTED FOR THE

CONNECTION WITH A SAFETY VALVE AND THERMOCOUPLE"

The present invention relates to a thermocouple connector, which thermocouple connector comprises: a phase conductor and an earth conductor and which connector is adapted for the electrical connection to a gas safety valve, which safety valve has a phase terminal and an earth terminal, the connector comprising: a phase terminal connectable to the phase conductor of the thermocouple and connectable to the phase terminal of the safety valve, an earth terminal connectable to the earth conductor and to the earth terminal of the safety valve and an insulating body inside which the phase terminal of the connector is housed and outside said insulating body the earth terminal of said connector is provided, the insulating body further comprising a plurality of axial slits that generate a crown of axial fins separated from each other and extending from the engagement end of the connector with the safety valve for a certain axial length towards the opposite end of said connector.

In the state of the art, there are known different types of coaxial connectors for connecting the thermocouple to the terminals of the electromagnetic system ensuring the automatic closure of the gas flux in absence of a flame, i.e. to a so called safety valve or cock of the gas flow.

Document EP619460A1 discloses a connector comprising a cylindrical insulating body inside which a female terminal is hosted which is connected to a phase conductor of the thermocouple and a metallic terminal provided on the outside of the insulating body and which surrounds the said insulating body and being destined to connect electrically and provide an electric continuity with a earth conductor of the thermocouple. The female terminal is suited to be coupled to a male phase terminal provided on the electromagnetic safety valve. The said electromagnetic valve comprises indeed an earth terminal similar to a collar, such that when the earth terminal is coupled to the electromagnetic valve, the insulating body and the phase terminal are housed inside the collar, while the metallic earth terminal is positioned outside of the collar.

Document EP2182584A1 discloses a coaxial connector for a thermocouple comprising a phase terminal secured to an end of a phase conductor of the thermocouple, an earth terminal secured to an end of the earth conductor surrounding the phase terminal, and a insulating body inside which the phase terminal is secured. The earth terminal has an essentially cylindrical geometry with an end which is mounted concentrically outside the earth conductor. The earth terminal is suited for being coupled externally to the earth terminal of the electromagnetic valve. On its turn the insulating body comprises axial slits which are positioned at identical distances one from the other at an end which renders the insulating body more flexible for facilitating the insertion in the electromagnetic valve.

Document EP2802042 discloses a connector according to the preamble of the principal claim. As it appears evident from the document, the constructive solution results relatively complex, although it is functional. The earth terminal is made like a barrel with arched mantle walls and which are formed by a plurality of plates which are spaced in a circumferential direction one from the other and which are joined together at the axial ends respectively by a head ring to which the said plates are connected. The head rings are open at a slit between two adjacent axial plates so that the terminal can be radially widened for coupling to an insulating body by positioning around the said external side of the said insulating body.

The construction of the earth terminal conceived in this way is complex and not deprived of risks, considering the small dimensions of the material ad of the constructive parts.

The present invention aims thus to overcome the disadvantages of the known art providing a connector for a thermocouple according to the description at the beginning which is nevertheless less costly more robust and simpler to be produced and which even in the stored condition is not delicate and sensible to damaging.

The invention solve the posed problem with a connector of the kind described at the beginning and in the preamble of the independent claim , and in which connector the earth terminal of the connector consists of a bushing open along an axial band and which bushing is shaped and made of electrically conductive material with elasticity that allows a radial widening of said bushing, while the wall of said bushing has elastically compressible bands angularly distributed along the circumference thereof, which bands consist of bands of material of said bushing, which are bent radially towards the outside so as to take an arc-shaped profile, radially outwards.

According to an embodiment, the angular extension of said bushing is between 180° and 300°.

According to still a further embodiment, at a band of said bushing opposite the opening area thereof, said band extends beyond a head side of the bushing, forming a fastening terminal for an earth conductor.

In one embodiment, said bushing is housed in a circumferential recess of corresponding shape, provided on the outer side of the insulating body.

In one embodiment, said circumferential recess has a diameter substantially corresponding the diameter of said bushing in rest condition, i.e. not elastically deformed.

In an embodiment which can be provided in combination with one or more of the preceding embodiments and variants described above, the insulating body extends for a predetermined extent beyond the head side of the circumferential recess for housing said bushing, said extension stretch being provided with a radial step-like widening at its end, which radial step-like widening is tapered conically to form a coupling guiding surface in the terminal of the safety valve.

In a further embodiment, at least the section projecting beyond one of the head sides of said earth terminal bushing is made of separate axial sectors due to through axial slits, which divide the wall of said section into wall sectors, said slits extending up to the head end of said protruding section.

A variant provides that said slits extend also at least for part or for the entire axial length of the bushing and in the area of the circumferential recess.

According to still a further feature which can be provided in combination with the one or more of the preceding embodiments and variants, wherein the phase terminal consists of a tubular element intended to be mechanically and interlockingly engaged in an axial hole of the insulating body, and which tubular element has an annular radial narrowing in an intermediate area of the axial extension.

In an embodiment which can be provided in any combination or sub-combination with one or more of the features and/or of the embodiments or of the variants described above or described in the following, the said phase connector, or the tubular element of the same one shows a cylindrical shape and a construction being symmetric in rotation preferably rotationally symmetric for an angle of 180°, or symmetric relatively to a diametral, axial plane of the said body.

An embodiment provides that said tubular element is also made open along an axial band. A variant embodiment may provide that the said axial slit provided on the tubular element is coincident with the incidence line of the said diametral, axial plane of symmetry with the mantle wall of the said tubular body.

According to still a further feature which can be provided in any combination with one or more of the features and of the embodiments described before, substantially at said radial, annular narrowing, said tubular element is made of a plurality of axial thin plates separated by axial slits, said thin plates connecting at their ends to the remaining part of the tubular element.

According to still a further variant embodiment, the annular radial narrowing of said tubular element comprises an initial narrowing section and a final widening section, which are progressive and/or substantially conical.

An embodiment provides that the said tubular element forming the phase connector shows a cylindrical section having a bushing-like shape on the side of the radial narrowing opposed to the insertion end of the said connector the said bushing being essentially coaxial relatively to the said radial narrowing and the axial slit extending along the said bushing, while the said cylindrical section shows an axial length of the order of magnitude of the axial length of the section comprising the said radial narrowing and while there are provided at least two interlocking locking wings of the phase connector in the insulating body, which wings are formed by portions of the wall of the said cylindrical section which are separated from the resting wall of the said cylindrical section by cuts.

According to still an embodiment and as it will appear more clearly in the following, the extension of the earth connector carrying the to the connection terminal of the earth connector is provided in coincidence with a narrowing of corresponding shape in the external mantle wall of the insulating body when it is in the mounted condition on the said insulating body.

Further features of the invention are subject matter of the dependent claims.

The features of the invention and the advantages deriving therefrom will appear more clearly from the following description of an exemplary, non-limiting embodiment illustrated in the annexed drawings in which:

Figure 1 shows in a high schematic view the phase terminal and the earth terminal of a safety valve and an axial connector with the corresponding terminals of a thermocouple, in the condition before insertion and in the condition after the insertion respectively .

Figures 2 and 3 show a perspective view of the connector according to the present invention according to two direction of view.

Figure 4 show the tubular element which forms the phase terminal of the connector.

Figure 5 show the rider like element forming the earth terminal of the connector.

Referring to figure 1, a and b, in the same figures show in a very schematic way the earth terminal and the phase terminal of a safety valve or cock.

In combination with this one and always in a schematic way, there is shown the connector of a thermocouple simply by reference to the constructive parts relating to the insulating body and to the phase and earth terminals.

For simplicity sake and also being clear to a skilled person the constructional particulars of the thermocouple, of the conductors and of the connection terminals of the said signal conductors have been omitted.

As put in evidence in the schematic figure 1, there is shown a terminal of the safety cock or valve comprising a central phase terminal 1 in the form of a male terminal and to which a female terminal corresponds on the connector of the thermocouple, i.e. a tubular terminal 10 which is provided on the said connector.

In an analogous way, the earth terminal 2 on the safety valve is provided in the form of a bushing which is placed coaxially to the phase terminal 1.

On the thermocouple connector, the earth terminal 12 is destined to operate as a male terminal which inserts inside a female terminal 2.

The male earth terminal 12 and the female phase terminal 10 of the connector of the thermocouple are in turn electrically connected to a corresponding earth terminal and to a corresponding phase terminal which are not shown in the figure but which constitute a usual constructive element of the thermocouples for the transmission of the signal generated by the same ones to a user unit. In any case the documents of the state of the art cited show the said conductors and their connections to the connector and the disclosed configuration is essentially analogous in the embodiments of the present invention.

As it appears from the figures la and lb, the phase terminal 10 and the earth terminal 12 are electrically separated one from the other by a intermediate wall of insulating material which is formed by a insulating tubular body 11.

In figure 1 a and 1 b, the insulating terminal shows an insertion end 111 being conically tapered and the said end is formed by conical teeth at the end of a plurality of axial plates as it will appear with more details in the following description.

The plates are separated by axial through slits extending till to the head end of the insulating body

11 on the insertion side thereof, so that thanks to the conical surfaces, the connector can penetrate inside the cylindrical earth terminal 2 of the safety valve, bey being radially compressed in the measure necessary to enter inside the cylindrical earth terminal and afterwards the elastic return generates furthermore a compression force of the earth terminal

12 of the thermocouple connector against the internal surface oof the earth terminal 2 of the safety valve. Figures 2 and 3 show an embodiment of the present invention.

The connector has a supporting body 11 of insulating material, for example of plastic material and which insulating body 11 is made with a essentially cylindrical or tubular shape. The central axial bore is destined to house the female phase terminal 10 of the connector which is shown in figure 4 and which is interlockingly locked inside the said bore thanks to interlocking wings 210, 310 as shown in figure 4.

In an intermediate position of its axial extension, the insulating body 11 show a recessed annular band. The male earth terminal of the connector elastically engages on the said recessed annular band 112, which male earth terminal is in form of a rider in the illustrated embodiment.

The insulating body 11 is prolonged over the earth terminal 12 in the direction of the insertion end of the connector into the safety valve, with an end section 411. This end section 411 is formed by a crown of at least two, preferably more than two wall sectors which are spaced one from the other by axial slits having a predetermined axial length and which can cross the annular recess housing the earth terminal 12.

In the figures it appears clear the conical end tooth which is made as a sector of a conical surface having an angular width corresponding to the one of the associated wall sector.

On the side opposed to the one of insertion, the connector, i.e. the insulating body 11 shows an axial extension which extends itself beyond the corresponding head end of the earth terminal 12. This part 511 extends beyond the connection terminals 210 and 212 of the phase and earth terminals of the thermocouple. Figure 4 show an embodiment of a female phase terminal of the connector of thermocouple according to the preceding figures.

In the illustrated embodiment, the said terminal is formed by a cylindrical element being axially opened by a continuous axial slit 410. The tubular element shows an annular narrowing like a constriction in a predetermined intermediate zone, which zone is preferably displaced more towards the end associated to the insertion end of the connector.

The said narrowing indicated by 510 shows a central section which is essentially cylindrical and which connects to the cylindrical wall of the tubular element with a conically tapered section and with a widening section essentially inverted relatively to the tapered one of narrowing which sections are indicated by 610 and 710.

In the zone of the said narrowing, the wall of the tubular element is formed by a plurality of axial plates 810 which are separated by axial slots 910. The plates 810 departs from a cylindrical section having a predetermined diameter and end in a cylindrical end section having a diameter essentially analogous to the one of the cylindrical section form which they are departing.

Wings 311 and 310 interlockingly engage seats in the cylindrical body 11 and locks at least in axial position the said tubular element.

The head end opposed to the one of insertion prologues on an angular band being more narrow till to a connection terminal 210 of the phase conductor (not shown). This terminal can be of different kinds and can provide a connection according to different modalities like crimping and or soldering and/or brazing and/or other existing systems of electric connection .

As it appears evident from figure 11, the phase connector 10 shows a cylindrical cross section and the axial slit is positioned along a line of intersection of a diametral plane with the said cylindrical shape, the said plane forming the bisector of the band of the longitudinal wall which is diametrically opposed to the said axial slit and of the extension of the said band which ends with the connection terminal 210 of the phase conductor.

The retaining wings by interlocking of the phase connector 10 inside the cylindrical insulating body 11 are placed preferably diametrically opposed one from the other, this means symmetrically relatively to a diametral plane coincident with the axial slit 410 and which plane cuts axially the phase connector 10 and the said wings are provided in the form of U- shaped cuts of a cylindrical wall 312 which extends for a certain axial length between the portion provided with axial plates 810 separated by the axial slots 910 which is opposed to the insertion end of the connector and the connection terminal 210 of the phase conductor to the phase connector 10. Preferably said cylindrical section 312 show an axial length essentially of the order of magnitude of the section showing the said plates 810.

Thanks to this construction, the phase connector 10 show a structure which is resistant and which is able to confer for a long time a sufficient radial contact force of the plates against a terminal pin or finger which is inserted by elastic forcing between the plates 810 in combination with a sufficient return elasticity in the resting condition without losses of resilience.

The earth terminal 12 of the connector of the thermocouple is illustrated in figure 5. As already described with reference to figure 2 the said terminalk is in the form of a rider and shows a bushing portion which engages on a cylindrical the end wall of an annular recess 112 already described before.

The bushing being axially opened is indicated by 500 and has an angular extension of less of 360° and is made of electric conductive material, but in any case sufficiently elastically deformable so that the bushing can be radially dilated in a predetermined measure which is sufficient to engage on the insulating body in the recess 112.

Elastically yielding or deformable contact protrusions are distributed, preferably but not necessarily at equal distances one from the other, along the circumference of the said bushing 500.

In particular, these protrusions are in the form of axial bands 501 which are generated by deformation of the wall of the bushing in such a way to form radial protrusions on the outer side and recess on the inner side of the wall of trhe bushing 500.

Thanks to this arrangement, in a coupled condition of the bushing 500 inside the cylindrical terminal of the valve, as schematically illustrated in figure 1, the said protrusions indicated by 501 are elastically pressed by the interna surface of the said cylindrical terminal 2 and exercise thus a pressure against the said surface generating a stable condition of electric contact.

Figure 5 shows three of these bans which are angularly identically spaced one from the other. Nevertheless, as already said this distribution is not be intended as limitative but can be varied as it is liked.

In an analogous way, at the phase terminal, on the head side opposed to the insertion one, the bushing 500 extends axially till to a connection terminal of an earth conductor. The connection terminal 212 can be of the kind suitable to an electric connection by means of crimping and/or soldering, and/or brazing and/or any other method of electric connection whichever.