| 摘要 |
<p>PURPOSE:To decrease contact area between a wire passing head and the inner surface of a conduit line as well as the outer surface of a cable and reduce frictional resistance by a method wherein the title head is provided with an annular soft tube, having a multitude of venting holes distributed on the surface contacting with the outer surface of the cable, and a soft porous core body, accommodated in the annular soft tube. CONSTITUTION:A wire passing head 10 is provided with a propulsive force at the front part of the fore end 11a of a tube 11 and the rear part of the rear end 11b of the tube 11. On the other hand, a resistant force, decreasing the propulsive force, is generated from friction forces on the upper and lower parts of the fore end 11a and rear end 11b of the tube 11 and the frictional force on the outside surfaces of both sides 11c. Even when the annular profile of the tube 11 is elongated or contracted or when the propulsive force is changed slightly, contact area between the tube 11 and the conduit line 1 or between the tube 11 and the cable 2 is not changed substantially whereby no change may be generated in the friction force applied on the tube 11.</p> |
