PURPOSE: To smoothly carry out covering work of a corrugate sheath to a PC steel wire by supporting a support roller free to rotate between support rods by way of providing the support rods through connecting rods at vertical parts of a gate type support frame.

CONSTITUTION: Smooth binding work is carried out at the time of the binding work without no obstruction around PC steel wires as support of the PC steel wires is released between each of support rollers 14. Additionally, at the time of traction operation of a corrugate sheath at covering work of the corrugate sheath after the binding work of the PC steel wires is finished, when the support roller 14 on which this corrugate sheath is placed is rotated, friction of the corrugate sheath and the PC steel wire is extensively reduced only at a part where a contact part of the corrugate sheath and the PC steel wire is supported by the support roller 14. Consequently, traction force of the corrugate sheath can be small. Accordingly, the covering work can be smoothly carried out.