DUST INCURSION PREVENTIVE CAP

摘要

PURPOSE: To prevent formation of a gap with a peripheral wall defining a penetrating hole even when a guiding track is fixed by a bolt with the guiding track fixing bolt made eccentric to the axial center of the penetrating hole for fitting the bolt and to easily and quickly perform attaching/detaching of the bolt when the fixed position of the guiding track is readjusted. CONSTITUTION: A dust incursion preventive cap 11 is provided with a disk-like cap part 12 and a semi-cylindrical inserting part 13 formed integrally with the cap part 12. The inserting part 13 is formed within the range of 180 degrees relating to the cirumferential direction R of the cap part 12.