Method and apparatus for electrically testing telecommunications cables

• US 4,794,339 A
• Filed: 11/01/1985
• Issued: 12/27/1988
• Est. Priority Date: 10/30/1985
• Status: Expired due to Fees

• Current Assignee: Nordx/CDT Inc. (Belden Inc.)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: LeNir, Victor L., Valois, Paul, Roberge, Jean-Marc
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Snow, Walter E.
• Application Number:
  US06/793,944
• Time in Patent Office: 1,152 Days
• Field of Search: 324/51, 324/52, 324/54, 324/66, 324/158 F, 324/150 P
• US Class Current: 324/540
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72
• CPC Class Codes: G01R 31/60 Identification of wires in a multicore cable

Abstract

Testing of conductors of a telecommunications cable in which, after stripping cable material surrounding one end of the core, the conductors in the end are separated from one another and are embedded within a dielectric material. The dielectric material is initially flowable and is caused to fill spaces between the conductors. After hardening, the dielectric material forms a solid mass with conductor end portions embedded within it. A planar end face is then formed on the solid mass with the electrically isolated conductor ends terminating at the end face. An electrically conductive probe is then moved successively into contact with exposed conductor ends to pass an electrical current to be passed into the ends to enable measurements to be taken of any desired electrical property.

Claims

1. A method of electrically testing conductors of a telecommunications cable having a cable core comprising a plurality of individually insulated electrical conductors in which the method comprises:

providing the core with one end which is stripped of surrounding cable material;

separating the conductor ends from one another at said one end of the core;

causing a flowing hardenable dielectric material to fill spaces between the separated conductors;

hardening the material to form a solid mass in which the conductor end portions are embedded in fixed relative positions and are electrically isolated from one another, the solid mass reflecting light at a different intensity from that of the conductor ends;

removing some of the hardened material and part of each conductor end portion to provide a planar end face of the solid mass with the eletrically isolated conductor ends terminating at and exposed at said end face;

directing light at the end face and monitoring light reflected from the end face;

converting the monitored light into signals in which light signals from the conductor ends differ from those for the solid mass and storing the signals in a memory; and

subsequently contacting the exposed ends of conductors to be tested with a single electrically conductive probe while moving the probe, dependent upon the stored signals, from conductor to conductor so as to contact sequentially each conductor to be tested, passing an electrical current through the probe and into any conductor which it contacts, and measuring the value of a desired electrical property as the current passes along said conductor.

2. A method according to claim 1 wherein the cable has a shield surrounding the core in which the method comprises grounding the shield and, with a conductor electrically isolated from all other conductors, passing the current through the conductor and measuring the capacitance of said conductor to the shield to indicate any electrical short between said conductor and any other conductor.

3. A method according to claim 1 comprising connecting the opposite end of the cable to ground, passing the current into a conductor at said one end and measuring the resistance to ground to indicate any electrical short between said conductor and any other conductor.

4. A method of testing conductors of a plurality of telecommunications cables each having a cable core comprising a plurality of individually insulated electrical conductors comprising testing the cables according to claim 1 in succession in which one cable is located in a work station with exposed ends of said one cable being contacted by the probe, while a succeeding cable is having its solid mass of material prepared and its planar end face provided and is then being located in another work station.