EP0398770A1 - Connection device for a coaxial cable, particularly for connecting an antenna to a car radio - Google Patents

Abstract

The device comprises: a metal part (4) provided with a tubular appendage (7); a connecting element (8); and an insulating central body (10) placed between the abovementioned metal part (4) and the connecting element (8). The insulating central body (10) comprises a radial passage (11) suitable for receiving one end (12) of the stripped core of the coaxial cable and a housing (13) into which the passage (11) emerges; the abovementioned connecting element (8) comprises a portion suitable for engaging in the housing (13) and for causing the bending of the end (12) of the core of the coaxial cable and the gripping of this end folded over against the surface of the central body so as to establish the electrical linkage between this core and the said connecting element (8). <IMAGE>

Description

The invention relates to a connection device for a coaxial cable, in particular for connecting an antenna to a radio station, a device of the type which includes: a metal part intended to be electrically connected to the metal braid of the coaxial cable, this part being provided with a tubular appendage adapted to receive one end of this coaxial cable; a connection member intended to be connected to the core of the cable; and an insulating core placed between the aforesaid metal part and the connection member.

Connection devices, of the kind referred to above, known to date require relatively delicate and expensive manipulations for their mounting and for establishing the electrical connection between the connection member and the core of the coaxial cable, this connection generally being established by tin soldering.

The object of the invention is, above all, to provide a connection device for coaxial cable which is of a simple and economical construction, and which enables the electrical connection, seamless, to be established quickly and reliably between the 'connecting member and the cable core, especially in the case of mass production.

In particular, it is desired that the assembly and establishment of the electrical connection can be carried out automatically.

According to the invention, a connection device for a coaxial cable, of the kind defined above, is characterized in that the aforesaid insulating core has a passage, substantially radial, in the extension of the tubular appendage, suitable for receiving one end of soul stripped of the coaxial cable and a housing extending transversely with respect to the mean direction of the aforesaid appendage, housing in which the passage opens, the aforesaid connection member comprising a part capable of engaging in the housing and thus causing folding of one end of the core of the coaxial cable projecting into this housing, and the clamping of this folded end against a surface of the core so as to establish the electrical connection between this core and said connecting member.

The metal part intended to be electrically connected to the braid of the coaxial cable can be formed by an envelope, in particular cylindrical or prismatic, inside which the core is placed, while the connection member is coaxial with said envelope; in this case, advantageously, the core is traversed axially by the housing, which opens at each end. The metal casing may include a transverse bottom provided with an opening allowing the connection member to be introduced through the bottom of this casing. The core of the coaxial cable is then folded back on the side opposite the bottom. It would, of course, be possible to introduce the connection member on the side opposite the bottom.

Advantageously, a metal plate is provided to close the bottom of the envelope after the connection member has been put in place, in order to complete the shielding. This closing plate can be constituted by a folding door, linked to the envelope on a part of its periphery, said door being able to be closed after the connection member has been put in place. Such a door is generally provided in an envelope made of cut or stamped sheet metal.

The above metal part of the device can consist of an extended washer radially by a connection lug forming the tubular appendage, this washer being in abutment against a flat transverse face of the insulating core, while the connection member is constituted by another washer, in abutment against the other face of the insulating core , the washer forming the connection member comprising at least one tab folded back towards the core relative to the mean plane of the washer, this tab being able to engage in the housing of the insulating core.

This transverse housing can be constituted by a recess provided in the thickness of the wall of the core and crossed by the aforesaid passage, the tongue of the connection member being adapted to engage in this recess by folding down the stripped core of the cable against the wall of this recess and by applying pressure against this core.

One of the two elements constituted by the tongue or the wall of the recess against which the exposed core rests has a certain elasticity, favorable to the establishment of electrical contact.

According to another possibility, the transverse housing is constituted by a central opening of the core passing through it right through, while the connection member comprises a washer provided on its internal edge with a crown folded down substantially at right angles to the mean plane of the washer, this crown being able to engage in the opening of the core by folding the end of the stripped core of the cable and establishing the electrical connection.

The crown may include a cut, elastic tab capable of establishing contact with the core of the coaxial cable.

Alternatively, the crown has a continuous rim, while an elasticity of the components and / or an appropriate clearance are provided to allow a tightening of the cable core, without tearing.

In the case of a car radio antenna base, intended to be mounted on a wall, a fixing screw, electrically linked to the antenna, is provided for mounting the base on the wall, this screw passing through the core insulating.

The connection member of the connection device can then comprise a metal body, linked to the screw, capable of clamping the core of the coaxial cable against a part of the core.

The metal body may be integral with the screw and formed by smooth bulging of the screw rod.

According to another possibility, the metal body is constituted by a nut embedded in the core, and into which the screw rotatably mounted in the base can be screwed.

• La figure 1, de ces dessins, est une coupe axiale d'un dispositif de connexion conforme à l'invention.
• La figure 2 montre, également en coupe axi­ale, une autre réalisation d'un dispositif de connex­ion selon l'invention.
• La figure 3 montre semblablement à la figure 2, une autre variante de réalisation.
• La figure 4 montre une variante du disposi­tif de la figure 3.
• La figure 5 montre en coupe un dispositif de connexion pour une embase d'antenne dont l'organe de raccordement est prévu sur la vis de fixation.
• La figure 6, enfin, montre également en coupe une variante du dispositif de la figure 5.

The invention consists, apart from the arrangements set out above, of a certain number of other arrangements which will be more explicitly discussed below in connection with particular embodiments described with reference to the attached drawings, but which are in no way limiting.

• Figure 1 of these drawings is an axial section of a connection device according to the invention.
• Figure 2 shows, also in axial section, another embodiment of a connection device according to the invention.
• Figure 3 similarly shows in Figure 2, another alternative embodiment.
• FIG. 4 shows a variant of the device of FIG. 3.
• FIG. 5 shows in section a connection device for an antenna base, the connection member of which is provided on the fixing screw.
• FIG. 6, finally, also shows in section a variant of the device of FIG. 5.

Referring to Figure 1 of the drawings, one can see a connection device 1 for coaxial cable 2, in particular for connecting a motor vehicle antenna, in particular a roof antenna, to a radio station. The device 1 is intended to cooperate with a complementary device 3, very briefly shown in FIG. 1, which, for example, can protrude from the rear face of a car radio station.

The device 1 comprises a metal part 4 formed by a cylindrical or prismatic envelope 5, of axis A intended to be electrically connected to the metal braid 6 of the coaxial cable 2. The envelope 5 is provided with a tubular appendage 7, arranged radially, suitable for receiving one end of the cable 2. A mechanical connection is established between this appendage 7 and the cable, for example by crimping; the electrical connection between the end of the stripped braid 6, located inside the appendix 7 and this appendage can also be produced by crimping.

A connection member 8 consisting of a plug 9 is arranged coaxially with the envelope 5. The plug 9 is held in the envelope by an insulating core 10, in particular made of plastic, coaxial with the envelope 5.

The core 10 has a passage 11 of radial orientation, substantially in the extension of the tubular appendage 7, adapted to receive an end 12 of the stripped core of the coaxial cable 2. The core of the cable 2 can be single-strand or multi-strand . This passage 11 may have a funnel shape directed radially inwards to facilitate the entry of the end 12. Passage 11 opens into a housing 13 extending transversely with respect to the mean direction of appendage 7. In the case of the embodiment of FIG. 1, the housing 13 is coaxial with the core 10 and opens at each longitudinal end. The cross section of this housing 13 has the same circular or prismatic shape as the cross section of the plug 9.

An elasticity of the components and / or an appropriate clearance are provided at the plug and housing sections to allow tightening of the cable core, without tearing. The game can advantageously be provided only on the part of the periphery in contact with the core.

The metal casing 5 is open on one side, namely the upper side in the case of FIG. 1 and comprises, at its other end, a bottom 14 provided with an opening 15 making it possible to introduce the plug 9, into the core 10, through the bottom 14.

A metal cup 16 is advantageously provided for closing the opening 15 when the plug 9 has been put in place, so as to complete the shielding provided by the casing 5. This metal cup 16 can be constituted by a folding door, connected to part of its outline at the bottom 14, this connection forming a hinge. For mounting the plug 9, the door formed by the cup 16 is arranged substantially at right angles to the mean plane of the bottom 14 and is then folded against the bottom when the plug 9 has been put in place. Such a folding door is generally provided when the envelope 5 is made of cut or stamped sheet metal.

Establishing the electrical connection and mechanical between the antenna 2 and the device 1 immediately results from the foregoing explanations.

The end of the antenna 2 is stripped so that the end 12 of the core protrudes with respect to the insulating sheath 17 separating the core 12 from the braid 6. Part of this sheath 17 protrudes by relation to the stripped part of the braid 6.

The end of the cable 2 is then introduced into the tubular appendage 7, the core 12 being oriented substantially in the axial direction of this end.

The core 12 enters the passage 11 which is disposed opposite the appendage 7, and projects into the housing 13, until it comes to bear against the wall of this housing opposite the passage 11. The stripped portions of the the end of cable 2 have lengths such that the outer sheath 18 of this cable 2 penetrates sufficiently into appendix 7.

The plug 9 is then introduced through the bottom 14 through the opening 15 into the housing 13, which causes the end 12 of the core to be bent upwards and this folded end tightened against the interior surface of the core 10, thus establishing the electrical connection between the core 12 and the plug 9, and the mechanical blocking of this plug in the core 10 and the bottom of the casing 14 is closed by the cup 16, optionally foldable.

The plug 9 projects from the side of the core 10 opposite the bottom 16 over a length sufficient to be connected to a corresponding female part.

The folding of the end 12 on the side opposite the bottom 14 makes it possible to reduce the thickness of the core 10 comprised between the axis of the cable 2 and the bottom 14.

It is clear however that in a variant the core 10 can have a sufficient thickness on the side from the bottom 14 so that the end 12 is folded towards the bottom 14, that is to say in the opposite direction to that shown in FIG. 1. In this case, the plug 9 could be inserted into the housing 13 by the side opposite the bottom 14, the latter then being able to be completely closed and not to have an opening 15.

FIG. 2 shows a variant 101 of the connection device for a coaxial cable 102, with a view to connecting an antenna provided with a base 121, diagrammatically shown, to a car radio station connected to the other end of the cable 102. The base 121 comprises, in a conventional manner, a threaded rod 122 intended to pass through an opening 123 provided in the wall P. The blocking on this wall is ensured by means of a nut 124 which is screwed onto the rod 122.

The elements of the devices 101 in FIG. 2 playing roles similar to the elements already described in connection with FIG. 1 are designated by numerical references equal to the sum of the number 100 and the reference used in FIG. 1. The description of these elements will not be repeated or will only be carried out succinctly.

The metal part 104 intended to be connected to the braid 106 of the coaxial cable 102 is constituted by a metal washer extended radially by a connection lug 107 forming the tubular appendage. This lug is offset transversely, relative to the plane of the washer 104, so as to be more distant from the wall P. The washer 104 bears against the face of the core 110 facing the wall P so as to be clamped against this wall by said nucleus.

the connecting member 108 consists of another conductive, metallic washer 125 bearing against the other flat face of the remote core 110 of the wall P.

The washers 104, 125 and the core 110 are crossed by the rod 122. The nut 124, by tightening the washer 125 against the core, establishes an electrical connection between the rod 122, itself electrically connected to the antenna, and said washer 125.

The passage 111 is formed by a sort of radial notch provided in the wall of the core 110 on the side opposite to the washer 104 and opening onto the face of the core against which the washer 125 abuts.

The housing 113 is formed by a kind of well, substantially parallel to 1 axis of the core 110, provided in the wall of this core to cut the passage 110 and open onto the face of the core in abutment against the washer 125.

This washer 125 comprises a tab 126 folded down relative to its mean plane substantially at right angles, suitable for engaging in the housing 113, for a correct relative angular position of the washer 125 and of the core 110. the end 127 of the tab intended to be located in the bottom of the housing 113 has a curved shape giving it a certain elasticity.

It is immediately understood that for mounting, the stripped end of the core 112 is engaged in the passage 111, substantially in a radial direction, this core being substantially rectilinear.

When placing the washer 125 against the core 110, the tab 126 when entering the housing 113 folds the core 112 towards the bottom of the housing 113 and applies it against the surface of this housing as shown in the figure 2. The electrical contact between the member 108 (washer 125) and the core 112 is thus established.

Figure 3 shows a variant of realization of a connection device similar to that of FIG. 2.

The elements of the device of Figure 3 identical or similar to elements of Figure 2 are designated by a reference numeral equal to the sum of the number 100 and the reference used in connection with Figure 2; the description of these elements will not be repeated or will be made only succinctly. It will be the same for the following figures where the numerical references will be increased by 100 each time.

The main difference between the device of FIG. 3 and that of FIG. 2 resides in that the transverse housing 213, in FIG. 3, is constituted by the central opening of the core 210, which passes right through it.

The connection member 208 is formed by a washer 225 whose internal opening is bordered by a crown 226 folded back so as to engage inside the opening 213.

This crown 226 has an elastic tab 227 cut along two edges substantially parallel to the axis of the housing 213 and connected by a short side, forming a hinge, to the washer 225. The inner end of the tab 227 is curved so as to rotate its convexity against the internal surface of the core 210.

The passage 211, the bottom of which may be limited by an inclined surface S serving as a ramp for guiding the introduction of the core 212, as in the case of the passage 111, crosses radially the wall of the core 210 and opens into the opening 213. For mounting the connection device, the core of the cable 202 is stripped over a length sufficient for the end 212 of this core to penetrate, in a substantially radial direction, into the opening 213.

The connection member 208 (washer 225) is then placed on the core 210 by introduction of the crown 226 into the opening 213 so that the middle part of the tab 227 causes the end 212 of the soul towards the inside of the opening 213, against the internal surface of this opening. The core 212 is tightened elastically by the tab 227 against the wall of the core 210.

In the exemplary embodiments of FIGS. 2 and 3, an elasticity is provided at the end of the tongue 126 or of the tab 227, while the bearing wall provided on the core 110 or 210 is relatively rigid.

In the embodiment of Figure 4, there is provided a certain elasticity at the support wall of the sleeve 310

The main difference between the embodiment of Figure 4 and that of Figure 3 comes from the fact that the ring 326 has a continuous periphery. To avoid tearing of the end 312 of the core during the introduction of the crown 326 into the opening 323, it is possible to give a certain elasticity to the part G of the wall against which this end 312 bears. This elasticity can be obtained by providing a recess 328 behind the wall G.

According to another possibility, to avoid excessive tightening of the core 312, provision is made for a clearance or recess on the zone of the internal wall of the core 310 against which the end 312 is applied.

FIG. 5 shows a base 421 of the radio antenna, provided with a fixing screw 422, electrically linked to the antenna. Screw 422 passes through a hole 423 of the fixing wall P; an insulating sleeve M surrounds the screw 422 in the zone passing through the wall P. The screw 422 also passes through the insulating core 410, so as to be able to receive, on its projecting end, a fixing nut.

The connection member 408 comprises a metal body constituted by a smooth, cylindrical bulge 409, integral with the screw 422. This bulge 409 is suitable for clamping the end 412 of the core of the coaxial cable against a part of the core 410, formed by the internal surface of a bore 428 of diameter slightly greater than that of the bulge 409. The bore 428 is located on the side of the end 412 opposite the wall P, so that this end 412 is folded back to the opposite of the wall P. Clearances can be provided on the internal surface of the core 410 to avoid any risk of tearing of the end 412 during tightening caused by the action of the nut on the screw 422.

Figure 6 shows a variant of the base of Figure 5 for folding the end 512 of the core of the coaxial cable to the wall P.

The metallic body 508 consists of a nut 509 embedded in the core 510 and which cannot rotate relative to the core due to an external knurling 529. The nut 509 has a cylindrical extension 530, with rounded ends, in the direction of the wall P so as to fold the end 512 towards the wall P, and to clamp this end 512 against the internal surface of the core.

The antenna base includes a screw 522, of which only the lower end is shown, which can rotate freely in said base. The head of the screw 522 is preferably of the hexagon socket type.

The mounting of the base on the wall P is obtained by engaging the screw 522 in the nut 509 and rotating the screw 522 to block the assembly.

As indicated above, with or without elasticity, it is possible to provide a clearance on the internal diameter of the core, facing the folded part of the core of the coaxial cable to avoid its tearing.

Whatever the embodiment adopted, the solution of the invention allows simple and rapid assembly with establishment of the electrical connection between the core of the coaxial cable and the connection member in a reliable manner, without the need for a welding.

Claims (12)

1. Connection device for a coaxial cable, in particular for connecting an antenna to a car radio station, comprising: a metal part (4) intended to be electrically connected to the metal braid (6) of the coaxial cable, this part being provided with a tubular appendage (7) adapted to receive one end of this coaxial cable; a connection member (8) intended to be connected to the cable core; and an insulating core (10) placed between the said metal part (4) and the connecting member (8), characterized in that the said insulating core (10) has a radial passage (11), substantially in the extension of the tubular appendage (7), suitable for receiving one end (12) of the stripped core of the coaxial cable, and a housing (13) extending transversely relative to the mean direction of the above appendix, housing (13) into which the passage (11) opens, the aforesaid connecting member (8) comprising a part suitable for engaging in the aforesaid housing (13) and thus causing the end (12) of the core of the coaxial cable and the clamping of this folded end against a surface of the core so as to establish the electrical connection between this core and said connecting member (8). 2. Device according to claim 1 wherein the metal part (4) intended to be electrically connected to the braid of the coaxial cable is formed by a cylindrical or prismatic envelope (5), inside which is placed the core (10 ) while the connecting member (8, 9) is coaxial with said envelope (5), characterized in that the core (10) is traversed axially by the housing (13) which opens at each end, and that l metal enclosure (5) has a bottom (14) provided an opening (15) making it possible to introduce the connection member (8) through the bottom (14) of this envelope which makes it possible to fold the core (12) of the coaxial cable on the side opposite the bottom (14 ). 3. Device according to claim 2, characterized in that the bottom (14) of the metal casing is provided with a door (16) suitable for closing the opening (15) after introduction of the connecting member ( 8), and to complete the shielding, this envelope (5) being in particular made of cut or stamped sheet metal. 4. Device according to claim 1, characterized in that the metal part (104) is constituted by a washer extended radially by a connection lug (107) forming the tubular appendage, this washer (104) being in abutment against a flat transverse face of the insulating core (110), while the connecting member (108) consists of another washer (125), bearing against the other face of the insulating core (110), the connecting member ( 108) comprising at least one tab (126) folded back relative to its mean plane, suitable for engaging in the transverse housing (113) of the insulating core (110). 5. Device according to claim 4, characterized in that the transverse housing (113) is constituted by a recess provided in the thickness of the wall of the core and crossed by the above passage (111), the tongue (126) of the connecting member (108) being adapted to engage in this recess by folding the stripped core (112) against the wall of this recess (113) and by exerting pressure against this core. 6. Device according to claim 5, characterized in that one of the two elements constituted by the tongue (126) or the wall of the recess (113) against which the exposed core rests, has an elasticity, favorable to the establishment of electrical contact. 7. Device according to claim 5, characterized in that the transverse housing is formed by the central opening (213,313) of the core (210,310), passing right through, while the connecting member (208,308) comprises a washer (225,325) provided on its internal edge with a folded crown (226,326) suitable for engaging in the opening (213, 313) of the core by folding the end (212, 312) of the stripped core of the cable and establish the electrical connection. 8. Device according to claim 7, characterized in that the crown (226) comprises an elastic tab (227) cut out, suitable for establishing contact with the core (212) of the coaxial cable. 9. Device according to claim 7, characterized in that the crown (326) has a continuous periphery, while an elasticity of the components (G) and / or an appropriate clearance are provided to allow a tightening of the core ( 312) of the cable, without tearing. 10. Connection device according to claim 1 for a radio antenna base intended to be mounted on a wall (P), a fixing screw (422, 522) being provided for mounting the base on the wall, this screw passing through the insulating core (410, 510), characterized in that the connection member (408, 508) comprises a metal body (409, 509) linked to the screw, suitable for tightening the core (412, 512 ) of the coaxial cable against a part of the core (410, 510). 11. Device according to claim 10, characterized in that the metal body (409) is integral with the screw (422) and is constituted by a smooth bulge of this screw rod. 12. Device according to claim 10, characterized in that the metal body (509) consists of a nut embedded in the core (510) and into which can be screwed the screw (522) rotatably mounted in the base.

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