US3610812A

US3610812A - Connecting a submarine repeater and a submarine coaxial cable

Info

Publication number: US3610812A
Application number: US55369A
Authority: US
Inventors: Kahei Furusawa
Original assignee: Kokusai Denshin Denwa KK
Current assignee: KDDI Corp
Priority date: 1969-07-18
Filing date: 1970-07-16
Publication date: 1971-10-05
Anticipated expiration: 1988-10-05
Also published as: GB1323085A

Abstract

A device connecting a submarine coaxial cable and a repeater. The connecting device has a conductive anchor means disposed internally of an insulator intimately covering the outer surfaces of the anchor means axially and circumferentially. The insulator is made of a material capable of withstanding large compressive forces. The anchor means is electrically connected to the inner conductor of the cable and to the repeater. An open-ended conductive receptacle is provided with a cavity complementary to the configuration of the insulator and receives it therein snugly with the anchor means. The receptacle means is supported by the box of the repeater. The anchor means and the insulator increase in cross section from both ends thereof toward the middle and the device substantially eliminates miswatching of impedances in the connection.

Description

United States Patent Inventor Appl. No.

Filed Patented Assignee Priority Kahei Furusawa Tokyo-to, Japan July 16, 1970 Oct. 5, 1971 Kokusai Denshin Denwa Kabushiki Kaisha Tokyo-to, Japan July 18, 1969 Japan CONNECTING A SUBMARINE REPEATER AND A SUBMARINE COAXIAL CABLE (EPA MIC 107a [56] References Cited UNITED STATES PATENTS 2,938,067 5/1960 Werner 174/70 S 3,082,291 3/1963 Parkinson 174/70 S X Primary Examiner-Darrell L. Clay Attorneys-Robert E. Burns and Emmanuel J. Lobato ABSTRACT: A device connecting a submarine coaxial cable and a repeater. The connecting device has a conductive anchor means disposed internally of an insulator intimately covering the outer surfaces of the anchor means axially and circumferentially. The insulator is made of a material capable of withstanding large compressive forces. The anchor means is electrically connected to the inner conductor of the cable and to the repeater. An open-ended conductive receptacle is prov vided with a cavity complementary to the configuration of the insulator and receives it therein snugly with the anchor means.

The receptacle means is supported by the box of the repeater. The anchor means and the insulator increase in cross section from both ends thereof toward the middle and the device substantially eliminates miswatching of impedances in the connection.

csLAss o2 CERAMIC CONNECTING A SUBMARINE REPEA'IER AND A .SUBMARINE COAXIAL CABLE This invention relates to ,a connector for connecting a submarine repeater and a Submarine coaxialcable.

Communication systems using submarine coaxial cables are broadly used to transmit a large capacity of telegraph and telephone information in overseas communication. In order to compensate transmission loss in a submarine cable, a number of repeaters are inserted at regular intervals in the submarine cable to realize a wide-band communication system. However, this conventional submarine cable system has a defect causing mismatching of impedance at the connection between each repeater and the submarine cable, so that it is difficult to realize a wide-band communication system having a frequency band considerably wider than the frequency band of the conventional system.

An object of thisjnvention is to provide a connector device connecting between a repeater and a submarine cable capable of reducing the mismatching of impedance at each connecting part. a

Another object of this invention is to provide a connector device connecting between a repeater and a submarine cable suitable to realize a wide-band communication system having a frequency band considerably wider than the frequency band of an ordinary conventional system. The construction and merits of the device of this invention will be better understood from the following more detailed discussion taken in conjunction with the accompanying drawings, in which similar parts are designated by the similar reference numerals, characters and symbols, and in which:

FIG. 1 is a longitudinal sectional view for illustrating an example of a conventional connecting device used to connect a repeater and a submarine cable;

FIG. 2 is a perspective view for illustrating an example of a submarine cable;

FIG. 3 is a longitudinal, sectional view for illustrating an example of a connector of this invention; and

. FIGS. 4 and 5 are longitudinal, sectional views each for illustrating a part of a connector of this invention.

To make the feature of the joint device of this invention clear, a conventional submarine cable connecting device will first be described. .With reference to FIGS. 1 and 2, a sub marine coaxial cable 1 comprises a'number of inner steel wires 2b for supporting a tensile force applied to the cable, an inner conductor 2a (e.g.; tubular copper) arranged around the inner steel wires 2b, an inner insulator 3 arranged around the inner conductor 2a, an outer conductor 4 arranged around the inner insulator 3, and an outer insulator 5 around the outer conduc tor 4. An example of a conventional connecting device shown in FIG. 1 connecting a repeater and a submarine coaxial cable 1 shown in FIG. 2 comprises a coaxial cable 1 having inner steel wires 2b, the inner conductor 2a, the inner insulator 3, the outer conductor 4 and the outer insulator 5; a coaxial cable la having construction similar to the coaxial cable 1 except that the inner steel wires 2b and the inner conductor 20 are replaced by a flexible copper wire; a sleeve 6 connected to the inner steel wires 2b; a disc-shaped anchor 7 connected to the sleeve 6; an insulator 8 surrounding the anchor 7; an anchor receptacle 9 consisting of two

parts

9a and 9b; a rubber boot l0 protecting the cablel; a thimble joint formed by the anchor receptacle 9, joint pins 1], rings 12 and a joint box 13; a bellows 14 protecting the connecting part; and a repeater box 51 forming a pressure space together with a cover 52 for seating a repeater circuitry 53. The cable la is inserted through a sleeve 54 to the pressure space and connected to the repeater circuitry 53. As understood from FIG. 1, the inner conductor 2a is connected through the sleeve 6, the anchor 7 and the cable la to the repeater circuitry 53, while the outer conductor 4 is connected through the anchor receptacle 9 and the joint pins 11 to the joint box 13 supported at the edge of the repeater box 51. Moreover, the tensible force applied to the cable I is transmitted to the repeater box 51 through the inner steel wires 2b, the sleeve 6, the anchor 7, the insulator 8, the anchor receptacle 9 and the thimble joint mentioned 2 above. In this case, since formations of theinner and'outer conductors un-uniformly vary at the position of the anchor 7, so that the above-mentioned mismatching of impedance is caused. I

With reference to FIG. 3, an example of the connector of this invention comprises further anreinforcement ring 17 arranged around the terminal part of the cable 1. Other parts are designated by the same reference numerals as the device shown in FIG. 1 except the anchor 7, the insulator 8 and the anchor receptacle 9. In this example, an anchor 107 is fixed so as to surround a sleeve 6 connected to both the inner steel wires 2b and the inner conductor 20 of the cable I, and the diameter of the transverse section of the anchor 107 gradually increases in the direction from ends to the center thereof. In other words, the anchor 107 is formed into a shape like as two circular cones coupled to each other so as to have a common base. A pair of insulators 108a and l08b having a large compressive strength such as ceramics or glass etc. are arranged so as to surround the surface of the anchor 107. Another receptacle consisting of two

parts

109a and 10% is formed so as to have an inner spaceexactly suitable to seat the anchor 107 coated with the pair of insulators 108a and l08b. As a result of the above constructiomthe tensile force applied to the inner steel wires 2b and the inner conductor 2a is applied as a compressive force to the pair of insulators 108a and l08b through the sleeve 6 and the anchor 107 and further transferred to the anchor receptacle (109a andl09b). Moreover, since respective shapes of the inner and outer conductors of a coaxial line between the two cables I and la is not abruptly changed, the characteristic impedance of this coaxial transmission system is almost not changed at this connector. The insulators l08a andl08b made of ceramics or glass have a high insulation resistance and a high compressive strength. Accordingly, since the insulators 108a and I08b of thin thickness sustains a high feeding DC voltage and a large tensile force, the connector can be formed in a small size as a whole. Moreover, if the outer diameter d of the anchor 107 and the inner diameter d, of the anchor receptacle (109a and 10%) are designed so that ratio d ld is substantially equivalent at the whole lengthlof the anchor 7 to a ratio of the diameter of the inner conductor 2a to the diameter of the outer conductor 4, more a uniform characteristic impedance of the coaxial transmission system will be obtained.

The anchor 107 can be designed so as to be formed of two parts 107a and I07b as shown in FIG. 4. In this case, the sleeve 6 is seated in the part 107a. In this example, the anchor (107a and l07b) has a spindle-shape in which the diameter of the transverse section gradually increases in the longitudinal direction from two ends to the center thereof.

The anchor 107 can be further modified as shown in FIG. 5, in which the anchor 107 is composed of two parts 107a and I07b having a diameter of transverse section varied exponentially in the longitudinal direction from two ends to the center thereof. The assemblage of the above-mentioned connector of this invention will be described with reference to FIG. 3. Respective contacting surfaces of the anchor 107, the insulators 108a and l08b and the anchor receptacle (109a and 10%) are made fit to one another. If necessary, films of soft metal (e.g.,

copper) or plastics may be adhered on respective contacting surfaces, so that the films of soft metal or plastics are completely close-contacted to the insulators 108a and l08b as a result of defonnation caused by the clamping pressure of the anchor receptacle (109a and l09b). To avoid leakage of .vapor from two

parts

109a and 10% of the anchor receptacle, an airtight mechanism using a ring 18 is provided around the part 10% of the anchor receptacle. Moreover, after the part 109:: and the part 10% are coupled to each other an extremely narrow cylindrical gap 19 between the two

parts

109a and 10% may be closed by welding.

In FIGS. 3, 4, and s, the insulator consists of two parts 108a. and 10%. However, this insulator may be divided into a plu-v the circumferential direction, so that divided parts are adhered to one another in assembling.

lclaim:

1. In combination, a submarine coaxial cable having an outer conductor and an inner conductor with insulation therebetween, a repeater having a repeater box, a connecting device connecting the submarine coaxial cable and the repeater, said connecting device comprising an electrically conductive anchor means, an electrically conductive sleeve in said anchor means receiving the inner conductor of said coaxial cable and connected thereto, said anchor means having a double-tapered configuration increasing in cross section dimension from both ends toward the middle thereof, insulation means intimately contacting the outer surfaces of the anchor means covering said anchor means axially and circumferentially and made of a material capable of withstanding substantial compressive forces, said insulation means having a symmetrical, double-tapered configuration longitudinally and increasing in cross section dimension from both ends toward the middle thereof, the insulation means making intimate con tact with said insulation in said coaxial cable, an electrically conductive two-part receptacle means connected to the outer conductor of said coaxial cable, said receptacle means having a double-tapered axial cavity open at opposite ends and having a symmetrical configuration axially complementary with said insulation means and in which said insulation means and anchor means are snugly held, said repeater box supporting said receptacle means, and a conductor electrically connecting the repeater with said anchor means, whereby impedance mismatching is substantially eliminated in said combination.

2. The combination according to claim I, in which said anchor means is spindle shaped.

3. The combination according to claim 1, in which said anchor means has a diameter increasing exponentially from said both ends toward the middle thereof.

4. The combination according to claim 1, in which said anchor means comprises two elements, one element having said sleeve therein and a recess extending axially thereinto, the other element having an axial projection received in said recess.

5. The combination according to claim 1, in which said insulation means comprises an insulator having two halves joined together.

6. The combination according to claim I, in which said twopart receptacle means comprises a first part having an axial bore having different diameters and open at both ends, a second part disposed in said axial bore jointly defining with said first part said cavity, and both parts clamping therebetween said insulation means and said anchor means therein.

7. The combination according to claim 1, in which said insulation means comprises two circular cones joined at the base thereof.

Claims

1. In combination, a submarine coaxial cable having an outer conductor and an inner conductor with insulation therebetween, a repeater having a repeater box, a connecting device connecting the submarine coaxial cable and the repeater, said connecting device comprising an electrically conductive anchor means, an electrically conductive sleeve in said anchor means receiving the inner conductor of said coaxial cable and connected thereto, said anchor means having a double-tapered configuration increasing in cross section dimension from both ends toward the middle thereof, insulation means intimately contacting the outer surfaces of the anchor means covering said anchor means axially and circumferentially and made of a material capable of withstanding substantial compressive forces, said insulation means having a symmetrical, double-tapered configuration longitudinally and increasing in cross section dimension from both ends toward the middle thereof, the insulation means making intimate contact with said insulation in said coaxial cable, an electrically conductive two-part receptacle means connected to the outer conductor of said coaxial cable, said receptacle means having a double-tapered axial cavity open at opposite ends and having a symmetrical configuration axially complementary with said insulation means and in which said insulation means and anchor means are snugly held, said repeater box supporting said receptacle means, and a conductor electrically connecting the repeater with said anchor means, whereby impedance mismatching is substantially eliminated in said combination.

2. The combinAtion according to claim 1, in which said anchor means is spindle shaped.

6. The combination according to claim 1, in which said two-part receptacle means comprises a first part having an axial bore having different diameters and open at both ends, a second part disposed in said axial bore jointly defining with said first part said cavity, and both parts clamping therebetween said insulation means and said anchor means therein.