Abstract: A cable holder is deposited and fixed on an inner wall of a sewage pipe made of resin and supports an optical fiber for communication, which is passed through the pipe. The cable holder has a longitudinal section similar to that of an inverted pot and a narrowed inlet opening, and is provided with a pair of claws arranged in the axial direction of a pipe at its upper part. A cable holder driving device is raised in a state where the cable holder is heated and a pair of claws are pressure-fitted into the inner wall of the pipe. The pressure-fitting is carried out to such a degree that the cable fitted to and supported by the cable holder is brought into contact with the inner wall of the pipe. After the cable holder is cooled down and fixed, the cable passed through the pipe is pushed in the cable holder through its inlet opening.

Abstract: A core drill of dry type used for drilling through concrete structure or the like. A main shaft 23 rotatably driven by a motor 33 with a fan 32 is provided with a rubber ring 27 for allowing axial vibration of the shaft, and loosely supported by bearings 25 and 26 with a clearance between them so that it can be slightly tilted in the lateral and transverse directions. During drilling, a spacing between a diamond tip in a leading end of the core bit and a concrete structure or the like is changed as the core bit is moved in the vertical direction and tilted in the lateral and transverse direction, and chips produced by the drilling operation are efficiently discharged by injecting air from the fan 32 through an axial bore 22 in the shaft 23.