Patent GB-398554-A (GB)
Title: Improvements in or relating to methods and apparatus for testing, measuring and coiling insulated strand materials
IPC: G01R31/02
Filed: 1932-03-18
Abstract: 398,554. Indicating and locating faults ; winding wire. WESTERN ELECTRIC CO., Ltd., Bush House, Aldwych, London.- (Electrical Research Products, Inc. ; 195, Broadway, New York, U.S.A.) March 18, 1932, No. 8170. [Class 37.] Apparatus for testing and coiling an insulated conductor, and adapted to stop automatically when a fault occurs, or when a predetermined quantity or length has been coiled, is provided with a take-up mechanism driven by an electric motor, testing electrodes, counting or measuring mechanism, and relay switching means, a single source of power energizing the motor, relay circuits and test electrodes. Stoppage of the apparatus occurs by the application of electromagnetic brakes. The insulated conductor is led around grooved wheels to one or more testing channels 30, Fig. 6, and between a galvanized steel mesh 29 and metal sash chains 32 forming the elec. trodes. Holes 37 in the web of the channel are provided to remove any dirt scraped from the conductor during the test. A removable guard is provided with slots so that the conductor can be threaded between the electrodes at 36. The coiling unit, Fig. 7, comprises two heads, one of which is filling while the other is bound, tagged and removed. The coiling heads are mounted to rotate freely on a shaft 59 and are provided with arms 65, 69, one of which may be pivoted outwardly from its normal position to release the coil. The heads are latched in turn at 94 to connect a motor 53 through clutches 78, 81 and gear 54. The electrical equipment which is provided throughout with interlocking switches is located below the testing unit and is wired to supply separate sources from the main switch 120 to the motor 53, test circuit 122, and counter 42. Foot-operated switches 133, 134 energize brake solenoids 17, 117, and on threading the conductor, switch 138 is closed to connect spark-gap apparatus 141 and primary 144 of the testing transformer, the secondary 136 of which is tapped for regulating the testing voltage. The fault relay 146 has a carbon arc 148 in circuit with its coil 145, the arc lighting so long as the conductor insulation is sound. On the occurrence of a fault sparking at the electrodes loads the secondary 136 and breaks down the gap 148. The fault relay 146 energizes lamp 156, buzzer 157, and stop relay 159, which operates a time delay spark cut-off mechanism 161, 163. This mechanism resets itself when the spark gap circuits are open. The exact position of a fault is located by operating treadle switch 152 to break the motor circuit, the testing potentials being maintained and auxiliary testing electrodes employed. The conductor is drawn manually until sparking occurs. The counter wheels co-operate with brushes 171, 172, 174, complete relay circuit 129, operate lamp 47, and stop relay 159 after a predetermined length of conductor has been coiled. The conductor may be coiled without testing by opening switch 181 to prevent excitation of the testing transformer. In order to make a cursory examination of the conductor insulation, the stop relay 159 can be opened by opening switch 182, and by manually opening and closing switch 181 intermittent tests can be effected.