PURPOSE: To avoid the loss of the propulsion force and external damage on a cable at a curved part by forming at least the contact surface for a cable of an endless tracked band into circular form.

CONSTITUTION: An endless tracked band 1 is formed by projecting the contact surface side with a cable C of an endless belt 5 laid between a pair of rollers 3 and 4 into circular form having a prescribed curvature, and an endless tracked band 2 is formed by recessing an endless belt 8 laid between a pair of rollers 6 and 7 into circular form having a prescribed curvature. Each pair of rollers 3 and 4 or 6 and 7 onto which the endless belt 5, 8 is laid or the continuous rollers 3 and 6 or 4 and 7 are installed in slidable ways, onto a base 10, and the side pressure for the cable C can be adjusted by revolution-operating a screw rod 11. With such constitution, a propulsion force is applied onto the curved part of the cable C at a curved part, and the loss of the propulsion force at the curved part is avoided, and the sufficient capacity can be developed independently from the rigidity of the cable.