Fujikura Limited

Tsuneaki Motai

Masataka Mochizuki

Michio Takaoka

Kouichi Mashiko

Motoyuki Ono

Masuji Sakaya

Shotaro Yoshida

Masakazu Hasegawa

Isao Kaji

Masayuki Tan

Masaru Kurata

Toru Takahashi

Hiroshi Yamanouchi

Toshio Niwa

Keiichiro Kataoka

Akihumi Onishi

Masakasu Hasegawa

A corrugated heat pipe sealed at both ends is disclosed, having a longitudinally corrugated peripheral wall and containing operating liquid therein. The corrugated heat pipe comprises inside a rope-like tension member extending therethrough in its longitudinal direction and secured at both ends. The rope-like tension member has the effect of preventing the corrugated heat pipe from elongation due to the weight thereof when the pipe is inserted in the ground, thus eliminating the possibility of local flattening of the corrugated outer periphery or of breakage of the pipe. Further, even when the coefficient of thermal expansion of the rope-like tension member differs from that of the corrugated heat pipe, since the corrugated heat pipe has its outer periphery corrugated in a wavy form in the longitudinal direction, it can sufficiently absorb the thermal expansion of the rope-like tension member. Thus, the corrugated heat pipe will not be broken, even when the coefficient of thermal expansion of the corrugated heat pipe differes from that of the rope-like tension member.

Corrugated heat pipe

A corrugated heat pipe sealed at both ends is disclosed, having a longitudinally corrugated peripheral wall and containing operating liquid therein. The corrugated heat pipe comprises inside a rope-like tension member extending therethrough in its longitudinal direction and secured at both ends. The rope-like tension member has the effect of preventing the corrugated heat pipe from elongation due to the weight thereof when the pipe is inserted in the ground, thus eliminating the possibility of local flattening of the corrugated outer periphery or of breakage of the pipe. Further, even when the coefficient of thermal expansion of the rope-like tension member differs from that of the corrugated heat pipe, since the corrugated heat pipe has its outer periphery corrugated in a wavy form in the longitudinal direction, it can sufficiently absorb the thermal expansion of the rope-like tension member. Thus, the corrugated heat pipe will not be broken, even when the coefficient of thermal expansion of the corrugated heat pipe differs from that of the rope-like tension member.

An apparatus for continuously producing a heat-shrinkable crosslinked resin tube from a crosslinkable resin is provided, comprising in successive connection, an extruder head for extruding the resin into a hollow tube, a fluid under pressure being introduced into the interior of the tube being extruded, a crosslinking cylinder disposed downstream of the head for heating the tubular resin for crosslinking, a flare die disposed downstream thereof for allowing the tube to expand under the fluid pressure, a cooling cylinder disposed downstream thereof for cooling the tube, a guide for deforming the tube into a flattened form, and rollers for pressing and drawing the tube away from the extruder head, wherein a smooth interior surface free of a substantial gap or step extends continuously from the crosslinking cylinder to the cooling cylinder.

Apparatus for continuously producing heat-shrinkable crosslinked resin

A method for jointing CV cables includes a lock mechanism which closes a split portion of a mold, used for extrusion-molding and opens the split portion by heat when crosslinking is performed.

Method for jointing CV cables

An apparatus for jointing CV cables includes a lock mechanism which closes a split portion of a mold, used for extrusion-molding and opens the split portion by heat when crosslinking is performed.

Apparatus for jointing CV cables

A DC power cable includes a conductor and an insulation of a thermoplastic resin formed around the conductor. The insulation contains carbon black in an amount of about 0.2 to about 5% of the total weight of the thermoplastic resin and the carbon black, and the ratio of mineral oil absorption (cc/100 g) to specific surface (m.sup.2 /g) in the carbon black is not less than 0.7. The carbon black has the hydrogen content of not more than 0.6% by weight. The specific surface is measured by BET equation. The carbon black has a particle size of 10 to 100 nm.

Growing community of inventors

Yachiyo, Japan

Tsuneaki Motai