EP0229549B1 - Hermetic coaxial connector - Google Patents

Description

The present invention relates to a hermetic coaxial connector of the type intended to be fixed to a panel to ensure a hermetic coaxial crossing of said panel.

Such coaxial connectors comprise a central conductive contact housed with interposition of insulation in a body forming an external conductor provided with means for fixing to a panel, a seal between said body and the panel, and a sealing member between the contact. central and the outer conductive connector body.

In the connectors of a first type, called direct sealing, the sealing member is a glass bead which is directly sealed at the central contact and at the external body.

These connectors have the disadvantage of being of a very high cost price because of the need to choose for the body a material suitable for sealing, such as, for example a ferro-nickel.

The body thus produced is fragile and can be easily damaged during assembly and / or disassembly of the connector on the corresponding panel, especially when the connector is of the screw type.

In addition, since the body is sealed by the glass bead in the central contact, it is not possible in the event of damage to replace only the external conductor.

In addition, in this type of direct-sealing connector, the actual sealing operation is relatively complex, requiring the use of graphite positioners matching the shapes of the outer body, the glass bead and the central contact.

The manufacturing cost of such connectors is therefore also high.

Another type of connector, known as an attached bead, is also known, the sealing member of which comprises an insulating glass bead sealed in central contact and with an annular ring housed in a recess of the body and fixed to the latter by soldering. at low temperature.

Compared to the first type of connector mentioned above, the pearl connectors offer the advantage of using more conventional materials for the body and therefore a lower cost price.

A very important drawback, however, lies in the need for a brazing operation which must be carried out at low temperature, of the order of about 200 ° C. in order to avoid degradation of the seal. For this brazing operation, it is necessary to carry out a preparation of the surface of the body, which is a delicate operation, difficult to automate, and requiring a precise implementation which leads to a high cost. In addition, there are risks of the appearance of a leakage path at the solder, which reduces the reliability of the connector.

In addition, as in the first type of direct sealing connector, it is not possible, because of the solder, to replace the external conductor in the event of damage without replacing the entire connector.

The present invention proposes to provide a hermetic coaxial connector precisely avoiding the drawbacks of the prior connectors mentioned above, in particular avoiding the use of expensive and fragile materials for the external body, requiring no soldering operation on the body and offering the advantage of allowing, if necessary, a replacement of the body without replacing the other elements of the connector.

The connector according to the invention comprises an insulating glass bead sealed at the central contact and to an annular ring housed at least partly in a recess in the body and is essentially characterized in that said ring has a stepped configuration comprising an axial annular bearing connected by the glass sealing bead to the central contact, an axial bearing in contact with a corresponding body bearing, a radial bearing bearing against a corresponding body bearing and a radial bearing in contact with the seal interposed between the ring and panel.

It is understood that the stepped ring structure according to the invention is in no way secured to the body forming the outer conductor, which allows the latter to be easily changed in the event of damage.

Conventionally, the connectors according to the invention can be mounted by screwing in a bore provided for this purpose in a panel, the body forming the outer conductor having for this purpose a thread, in which case the ring advantageously has according to the invention a section of reduced diameter, the radial end bearing of which bears against a corresponding bearing from the bottom of the panel bore, the seal being housed in a space defined by the bore of the panel, said section of reduced diameter the ring and said radial bearing surface of the ring making contact with the seal.

Alternatively, the connectors according to the invention may have a flange fixing in which case according to the invention, an assembly of the ring secured to the bead is made in a corresponding recess in the outer conductive body, the seal being housed in a space defined by the panel, the ring and the inner axial annular bearing surface of the flange.

Other characteristic advantages of the invention will appear on reading the following description with reference to the appended drawing in which:

FIG. 1 is a half-section view of a conventional hermetic coaxial connector of the attached bead type,

FIG. 2 is a view similar to that of FIG. 1 of a connector according to the invention according to a first embodiment,

FIG. 3 is a half-section view of a conventional hermetic connector of the direct sealing type and,

- Figure 4 is a view similar to that of Figure 3 of a connector according to a second embodiment of the invention.

The conventional hermetic coaxial connector of the attached bead type illustrated in FIG. 1 comprises a body 1 forming an external conductor intended to be fixed on a panel 2 and comprising on its external periphery a thread 3 intended to cooperate with a corresponding tapping 4 produced in the bore in the panel for the passage of the connector.

The connector comprises a central contact generally designated by 5 and an insulator 6 between the central contact 5 and the body 1.

The sealing between the central contact 5 and the body 1 is ensured by an insulating glass bead 7 sealed at the central contact 5 and to an annular ring 8 itself secured by a solder 9 to the body 1.

The seal between the body 1 and the panel 2 is ensured by a seal 11, for example a metal seal with low crushing.

Reference is now made to FIG. 2 which illustrates a first embodiment of a hermetic connector according to the invention which very generally has the same external appearance as the connector illustrated in FIG. 1.

There is a central contact 5 housed there with the interposition of an insulator 6 in a body 12 forming an external conductor, the front part of which, intended to be placed inside the panel, nevertheless has a structure somewhat different from that of the body 1 of the connector illustrated in FIG. 1.

The body 12 is like the body 1 provided with a thread 3 intended for mounting by screwing the connector on the panel 2.

As in the connector of Figure 1, there is provided a glass bead 7 sealed to the central contact 5 and a ring 13 made for example of iron-nickel FN 42 (Fe 48% alloy - Ni 42%)

As can be seen in FIG. 2, the ring according to the invention has a stepped structure with three external diameters, in the mode of illustrated embodiment, and extends to the seal 11 housed at the bottom of the panel bore.

More specifically, the ring 13 comprises a first section, an internal axial bearing 14 of which is in sealing contact with the glass bead 7 and an axial bearing 15 in contact with a corresponding axial bearing of the body 12.

This first section of the ring is extended by a section of larger outside diameter defining a radial bearing surface 16 for the front end of the body 12 and a radial bearing surface 17 bearing against the seal 11.

Finally, the ring comprises an end portion of reduced diameter whose radial end surface 18 comes to bear against the bottom of the bore of the panel, the seal 11 being crushed between the surface 17 of the ring and the wall of the panel thus preventing any leakage path between the body 12 and the panel.

Compared to the embodiment of Figure 1, we see that the solder 9 has been removed so that the body 12 is not sealed directly or indirectly to the bead 7 and it is therefore possible to replace it especially in case damage to its thread 3 without replacing the other connector components.

Reference is now made to FIG. 3 which illustrates a conventional hermetic connector of the direct sealing type and with flange fixing.

The connector comprises a body forming an external conductor 19 provided with a fixing flange 20 having orifices (not shown) for the passage of fixing members (not shown) on a panel 21.

The connector comprises a central contact generally designated by 22, mounted in the body 19 with the interposition of an insulator 23.

To avoid any leakage path between the central contact 22 and the body 19, a glass bead 24 is provided providing a direct sealing of an internal axial bearing 25 of the body 19 on the central contact 22.

To avoid a leakage path between the body 19 and the panel 21, there is provided a seal 26 housed in a recess made in the flange of the body.

To allow its adhesion to the glass bead 24, the body 19 as a whole is made of a material having good sealing characteristics, in particular ferro-nickel. Due to the sealing carried out along the surface 25, the body cannot be replaced in the event of damage without replacing the entire connector.

The connector according to the invention illustrated in Figure 4 has an overall appearance similar to that of the connector of Figure 3 but is differentiates on the one hand by the structure and the material of the body 27 forming the outer conductor and on the other hand by the presence of a stepped structure ring generally designated by 28 and sealed with the pearl 24 which is itself sealed with central contact 22.

The body 27, which can be made of a relatively inexpensive conventional material such as for example brass, like the body 12 of the embodiment of FIG. 2, does not extend as in the embodiment on FIG. 3 in the bore formed in the panel 21 but only has a rear part extended by a fixing flange 29, by means not shown in the panel 21.

The ring 28 of the connector according to the invention has an inner axial annular bearing surface 30 which, like the bearing surface 25 of the body 19 of the embodiment of FIG. 3, makes contact with the sealing bead 24, an axial bearing surface 31 in contact with a corresponding surface of the flange 29 of the body 27, a radial surface 32 bearing against a corresponding surface of the body 27 and a radial surface 33 in contact with the seal 26 interposed between the ring and the panel.

The ring 28 with a stepped structure according to the invention, which can be seen in FIG. 4, is put in place according to a "hard" mounting in a recess formed in the body 27 concentrically with the flange 29, the seal 26 being housed in the space defined by the panel, the ring and the inner axial annular bearing surface of the flange, this seal thus preventing any passage of leakage between the ring and the panel.

Because the body 27 with its flange 29 is not secured to the ring 28, it can be easily removed and replaced in the event of damage without requiring the replacement of other components of the connector.

The invention can be implemented with hermetic type connectors having other means of fixing to a panel, for example fixing by nut, the stepped configuration of the ring then being adapted to the particular structure of the connector.

Claims (3)

1. A hermetic coaxial connecter of the type intended to be fixed to a panel (2, 21) to ensure a hermetic coaxial passage through the said panel, comprising a central conductor contact (5, 22) housed, with interposed insulation, in a body (2, 27) forming the outer conductor, equipped with means for fixing to a panel, a sealing joint (11, 26) between the outer conductor (12, 27) and the panel, and an insulating bead (7, 24) made of glass sealed to the central contact (5, 22) and to an annular ring (13, 28) housed at least partially in a recess in the body, characterised in that the said ring (13, 28) exhibits a stepped configuration comprising an axial annular bearing surface (14, 30) connected by a glass sealing bead (7, 24) to the central contact (5, 22), an axial bearing surface (15, 31) in contact with a corresponding bearing surface of the body (12, 27), a radial bearing surface (16, 22) abutting against a corresponding bearing surface of the body, and a radial bearing surface (17, 33) in contact with the sealing joint (11, 26) interposed between the ring (13, 28) and the panel (2, 21).
2. A connecter as claimed in Claim 1 of the type intended to be screw-connected to a panel, characterised in that the ring (13) exhibits a section of reduced diameter, the end radial bearing surface (18) of which abuts against a corresponding bearing surface of the base of the bore of the panel (2), the sealing joint (11) being housed in a space defined by the bore of the panel (2), the said section of the ring (13) which is of reduced diameter and the said radial bearing surface (17) of the ring forming the contact with the sealing joint (11).
3. A connecter as claimed in Claim 1 of the type intended to be flange-connected to a panel, characterised in that the ring (23) is housed in a corresponding recess of the body (27), the sealing joint (26) being housed in a space defined by the panel (21), the ring (28) and the interior, axial, annular bearing surface of the flange (29) of the body (27).

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