PURPOSE: To rapidly tighten and fix a band around a connector housing by providing an advancing means having a power source to tighten the band around a sleeve by the prescribed tension in a drive track in cooperation with a gripping means.

CONSTITUTION: A rotating mechanism is provided with a knurled wheel 94 and a plurality of spring-energized pinch rollers 98 to grip a band 18. The torque to drive the knurled wheel is given by a worn gear assembly 74 of an advancing means through an adjustable clutch 96. The worn gear assembly 74 is connected to an air motor 42 or an electric motor. The tension is calibrated to the desired limit value by the adjustable clutch 96. An Oldham's coupling is provided between an output shaft of the motor 42 and an input shaft of the worm gear to cope with the mismatching in the axial direction.