PURPOSE: To sense passage of a cable joint contactlessly by sensing the pressure rise inside a conduit interposed between a cable seal device and a lead wire seal device in the condition, that the cable surface is sealed, when the joint of the cable and lead wire passes the conduit.
CONSTITUTION: When a joint Wb and a cable W pass through a cable seal device A following a lead wire Wa, the cable W and a seal packing 3 are put in closely contacted condition, and the hollow of a conduit 4 is isolated by packings 3, 5. Now the outside dia. of the passing wire increases gradually with movement, and the pressure in the hollow rises. This rapid rising phenomenon of the pressure is sensed by a pressure gauge 15 at a joint sensing device C, and a switching signal is given by a control part 16 to a selector valve 18, and the pressure of the packing 5 at a lead wire seal device B is released. This facilitates dia. enlargement of a seal hole 13 in the packing 5 so as to admit passage of the joint Wb and cable W.
TORII KAZUHIKO
SUZUKI YASUO
KATAOKA KEIICHIRO
