Cable sheathing and burying method

A method of continuously laying a sheath-protected cable assembly in a trench to provide an underground installation of the assembly and utilizing a vehicle means movable along the lien of the trench during the laying of the assembly comprising:

• providing on the vehicle an elongate stored supply of a plastic tubular sheath having a hollow interior, and an elongate stored supply of cable;
• in an assembly station on the vehicle and on drawing of the sheath through the station, opening the sheath along the wall thereof in a region extending along the length of the sheath and loosely lodging the cable within the interior of the sheath by directing the cable into the opening with the cable then becoming loosely lodged within the sheath encompassing it;
• the plastic sheath provided having a wall which, through memory and after opening, seeks a non-joined, closed condition along said region with the wall closing an itself in said region to produce a tight overlap of the sheath wall;
• after lodging of the cable permitting the wall of the sheath, through memory, to assume said non-joined, closed condition and to produce a tight overlap along said region and an assembly comprising the cable extending along the sheath with such loosely disposed therein;
• after the assembly exits the assembly station and in a training zone, training the assembly in bends whereby the assembly, on leaving the zone, extends along the trench and anchoring the assembly through anchoring of the sheath within the trench with such assembly deposited in the trench;
• vehicle movement along the trench with the sheath so-anchored serving to produce drawing of the plastic sheath in the assembly through the assembly station and thench through the training zone whence the assembly reaches its deposited position in the trench.

A method of laying a sheath-protected cable assembly in a trench to provide an underground installation of the assembly, which comprises:

• providing an elongate expanse of plastic tubular sheath having a hollow interior;
• opening the sheath along the wall thereof in a region extending along the length of the sheath and loosely lodging the cable within the interior of the sheath by directing the cable into the opening with the cable then becoming loosely lodged with the sheath encompassing it;
• the plastic sheath provided having a wall which through memory and after opening seeks a non-joined closed condition along said region with the wall of the sheath closing on itself to provide a tight overlap of the sheath wall in said region;
• after lodging of the cable, permitting the wall of the sheath through memory to assume said non-joined closed condition along said region and to produce a tight overlap along said region and an assembly comprising the cable extending along the sheath with such loosely disposed therein;
• and
• placing the sheath and cable assembly within the trench with the overlap in said region maintained by said memory in the sheath wall, and then filling in the trench and overlaying the assembly with fill material to produce the underground installation.