Initial tension device for wire cable and method of applying initial tension to wire cable

A device for applying initial tension to a wire cable which transmits driving power of a drive unit to a movable member, comprising:

• a tension case fixed to an immovable member, said tension case having an elongated space along a longitudinal direction of the wire cable;
• an insertion part connected to an end part of an outer cable of the wire cable and movably inserted into the elongated space;
• a regular retainer engageable with the insertion part;
• and
• a slot formed in the tension case and extending in the longitudinal direction of the wire cable;
• wherein said regular retainer engaged with the insertion part is movable together with the insertion part by tension applied to the wire cable through a length defined by the slot.