CH296133A - Method for making a joint between two sections of cable with coaxial conductors and joint obtained by this method. - Google Patents

Description

Process for making a joint between two sections of sand with coaxial conductors and joint obtained by this process. The present invention relates to a method for making a joint between two sections of sand having coaxial conductors and a joint obtained by this procedure.

Conventional axial cables comprise an inner conductor surrounded by a tubular outer conductor held concentric with respect to the first by regularly spaced separating insulating parts mounted on the inner conductor. l.je exterior eondueteur is generalemei@t obtained by longitudinal folding of a metal strip brought to the. tubular shape, the two edges of the ribbon being coineidene, parallel to. Sand fax. In some cases, the tape is pleated transversely to increase the flexibility of the sand. H-shape, into which the edges of the outer conductor engage. In addition, these cables are provided with an outer reinforcement of steel tape, which serves to hold the edges of the outer conductor together. against each other or against said Joint Strip and to form a magnetic screen.

You know coaxial cables are used. its for telecommunications being made at high frequencies and that at these frequencies structural discontinuities due to the joints established between two adjacent sections of cable introduce disturbances which alter the transmission characteristics of the sand.

To remedy this inconvenience, it is customary to execute the joints in such a way that they only introduce structural discontinuities on parts that are as short as possible. For this purpose, the inner conductors of the two sections of cable to be joined are connected by means of a sleeve slipped over it and welded together the two ends to be joined, while the outer conductors are likewise connected by a sleeve slipped over it. them and solder On the extremities of the two outer conductors. There is a small structural discontinuity and, therefore, an electrical discontinuity because the sleeve slides over the ends of the outer conductors and will have a slightly larger inside diameter than that of the outer conductors. .

Such coaxial cables are normally installed in trenches or are pulled in condLiits, and the joints between the various sections of sand are made on site, after the laying of these.

There is, however, a disadvantage in constructing such joints, since the soldered connections of the interior conductors and the two solder joints. The strains made between the ends of the outer sleeve and the two ends of the outer conductors are quite close together so that the entire joint is somewhat rigid and exposed to damage during flexing.

This drawback is less important when the joints are made after the final placement of the sections of sand, but it may be necessary to make joints between various sections of sand during manufacture and. then to transport the cable thus formed to the desired location.

It is obvious, for example, that the joints of a submarine cable must be made before the cable is laid. In this case, the seals in question must present as much as possible the same flexibility as the rope, so that the latter can be rolled up on drums located in the holds of a boat used for . 1a. lays cables and unrolls them using the machines provided for this purpose.

The present invention makes it possible to execute a joint between two sections of coaxial cable in such a way that it presents as much as possible the same flexibility as said sections and a low electrical discontinuity.

The process according to the present invention, which is a process for making a joint between two sections of sand with axial conductors and whose outer conductor is tubular and formed by longitudinal bending of a metal strip, is characterized in that over a certain length the outer conductor of at least one of said sections of sand from the end to be joined, in that one slightly enlarges on a long pie and on one side at least one outer conductor having the same dimensions and characteristics that the part lifts, in that the latter condition is opened longitudinally over a firne part of its length at least, in that the conductors are joined inside the two sections of eä. ble, in that one closes the first condutor which one had previously opened around the central conductors thus joined and in that one joint the enlarged end 6 of the conductor closes to the end of the shortened outer conductor.

The description which follows relates to two examples of implementation of the process according to the invention and to two forms of execution given by way of example of the joint according to the invention.

fig. l- of the arriiexe drawing represents -wie sectional view of a joint constituting the first form of execution.

fig. 2 represents a sectional view of a tool used during the construction of the Joint of FIG. 1.

fig. 3 represents a sectional view of another tool used for the construction of the same Joint.

In 1a. fig. 1, the ends 1 and ? of the two sections of cable to be retained are constituted by the external eonduteurs 3 and 4- coiipes at points: 5 and. 6 and by ].es interior conductors 7 and h which extend only at the eentre of the joint.

The outer conductors 3 and -1 are supported by insulating and separating disks 10, and identical disks 11 are mounted on the exposed part of the inner conductors 7 and B. As will be seen again in FIG. 1 two insulating units eoniposees ehaenne of pieces 12 and. 13. These finishes are water quenched. Part 12 is made of a resilient material, such as soft mud rubber, e1:0 is similar to a reciprocating hydraulic pump piston washer.

Room 13 is. a perforated disc Makes an insulating material Bure Pressed into the washer 1?.

The outer conductors 3 and 4 are connected by a crank 14, while the inner conductors are connected by a socket 9. by butt welding.

To establish the joint shown in 1a. fig. I; cm first removed at the end of each trunk of efitble a certain length of the condiicteui-exterior, and has siir interior conductors 7 and. 8 the two insulating units composed of lines 12 and 13. Then, an average sleeve 1-1 year of a certain length of external insulation having the same characteristics as the external conductors 3 and 4 of the sections of C Vble 1 and ?. This length of outer conductor can conveniently be a pike raised from one of the wire sections in order to make the joint. The length of the inanchon 1.1 is determined by the requirements and can reach 60 ein; it will normally take considerably more weight than in cases where sleeves for which flexibility is not important are used.

Then, slightly expands the ends of the crank pin 14- by means of the tool shown in FIG. ? and whose use is obvious. This dilation is. executed On a distant court, for example 1. ein.

After having expanded the two extrem.ites of the iiianelion 14 to form sleeves 1:i and 16, eelui-ei is opened first along the longitudinal seam which it possesses. This operation peels. be effected by inserting and drawing through the tube a swab whose large end has a fairly large diameter. fig. 3 represents such a rod which includes a handle 17 threaded on a brass rod 18 or on a line.

Other tools, of different shapes, can also be used to open the sleeve.

The sleeve 14 is then slid over the end of one of the two sections of cable to be joined; until it is located near the outer conductor of this section of sand. After this operation, the ends of the two interior conductors are connected, for example, to the means of a socket 9. This done, the open inanelion is placed until it covers the Denlide part of the interior conductors and then the edges of said sleeve are folded down, so that it then resumes its bular shape.

Bushings 15 and 16 are then welded to the ends of outer conductors 1 and 4, and the sand joint is completed by wrapping a steel tape not shown in the drawing.

It will be observed that the ratio between the internal diameter of the external conductors and that of the internal conductors is constant over the largest part of the Joint, so that any variation in impedance is avoided, and which makes it possible to manufacture the Joint. ä, the desired length.

Because the connection of the central conductors is at a certain distance from the sleeve and the outer conductors, the flexibility of the joint is not appreciably impaired.

In the second example of mixing in aeuv re of the process according to the invention, there is no separate outer sleeve. The ends of the cable sections to be joined are arranged so as to overlap over a considerable length, for example over approximately 20 to 30 mm or more, and. are held firmly.

The external eonduetor of the extremity of one of the two cable sections, that of Bauche, for example, is. then cut so as to leave only about 1 cm overlap with respect to the extremity of the outer conductor of the other stub. , Consequently, the interior component at the left hand will obviously protrude 20 to 30 cm in accordance with the covering. initial. The outer conductor of the other extremity, that is to say the one on the right, will be . opened with a suitable tool over a distance a little greater than the length of the projection of the extremity of the interior conductor of Bauche.

The end of this open part will be widened slightly, so that it can be subsequently welded to the end of the other outer conductor. Then, the end of the interior conductor placed on the right hand side Will be coupled so as to come end to end with the end of the interior conductor placed on the Bauche hand. The two interior conductors will then be connected as described above, then the open part of the exterior conductor placed at the right hand is closed edge to edge around the interior conductors thus connected, and the widened part of the latter is welded onto the extremity of the external conductor placed at, main Bauehe.

As indicated previously, the Joint is finally surrounded with steel tape,

Claims (1)

CLAIM 1: Process for making a joint between two sections of cable having coaxial conductors and the outer conductor of which is tubular and formed by longitudinal folding of a metal tape, characterized in that over a certain length the outer conductor of at least one of said sections of cable from the end to be joined, in that one slightly enlarges over a short length and at least one outer conductor has the same dimensions and. characteristics than the part removed, in that this last conductor is opened longitudinally over at least part of its length, in that the inner conductors of the two sections of cable are joined, in that the conductor which had previously been opened is closed around the central conductors thus joined and in that the enlarged end of the closed conductor is joined to the end of the bent outer conductor. SUB-CLAIMS 1. Process according to claim 1, characterized in that the outer conductor ä is removed over a certain length. eliacim sections of cable, ä, from the ends to be joined, in that one slightly enlarges over a short length the two ends of an external condticteiir before the same dimensions and. characteristics than the outer conductors of the cable sections to be joined and of a length slightly greater than 1a. total length of the exposed parts of the inner conductors of the two sections of cable, in that the last conductor is opened over its entire length, in that the last conductor is slipped around the outer conductor of one of the sections of cable to be joined before joining said inner conductors, in that said last conductor is slid so as to close the space between the outer conductors of the two sections of cable, after having joined the ends. upper conductors, and in that the two enlarged extremities of the closed econdutor are joined to Gelles by the outer eondiictors of the two sections of eaables. ?. The procedure according to claim 1, is characterized in that the extremity of the outer conductor of one of the sections of cable to be joined is slightly enlarged, in that one opens the external conductor RTI ID="0004.0276" WI="28" HE="4" LX="1237" LY="661"> longitudinally over a greater length, in that part of the conductor is removed interior of the section and. a slightly less lon-ue part of the extremity of the outer conductor of `1'autre section. 3. The following process, <B>1 a,</B> rev endieai ion I, characterized in that a steel tape is applied around the place where the two sections of cable are joined. CLAIM II: Joint, between two sections of maple with axial conductors obtained by the process according to claim I. SUB-CLAIMS: Joint according to claim 11, characterized in that it comprises im 5. Joint according to claim II, ca., characterized in that it is provided with 6. Joint according to claim <B>11,</B> characterized in that the outer joints of the two sections of cable are connected directly - ment by one end of one of them, shaped so as to extend on a flat bottom on the outer surface of the end of the other outer conductor.