Cable pulling apparatus

Abstract

A cable pulling apparatus includes a driving sheave on which is wound a tow line detachably connected to one end of a cable to be pulled; a pulling device disposed between the driving sheave and the end of the tow line and adapted to pull the tow line, a tension detector disposed between the driving sheave and the end of the cable and adapted to detect the pulling tension in the cable, and a control means for controlling the traction device in accordance with the tension detected by the tension detector such that, when the tension detected by the tension detector is below a predetermined limit, the pulling speed is controlled to impart a tension which is comparatively small but large enough to prevent any slip of the tow line on the periphery of the driving sheave, whereas, when the tension detected by the tension detector exceeds the predetermined level, the pulling speed is decreased such as to cause a slip of the tow line on the outer periphery of the driving sheave.

Dependencies are inferred from the claim text.