PURPOSE: To make it possible to easily mass-produce the title device at a low cost, with a preferable maintenance by providing plural engaging holes which are connected on a synthetic resin made continuous film in the longitudinal direction at a predetermined intervals.

CONSTITUTION: There are provided plural holes 1 on a synthetic resin made continuous film 2 in the longitudinal direction at a predetermined intervals. There are also provided a pair of belt wheels 4, 4' having plural engaging projections 3 which is continuously positioned in the circumferential direction at the above intervals. Connecting pieces 5 is hung to the drive/driven belts 4, 4' in the state where the engaging projections are inserted into the engaging holes 1. When the connecting piece 5 is cut out in driving, it is possible to match the cut surfaces and stick adhesive tapes 9, 9' on both surfaces thereof, thus enabling the temporary repair.