Abstract: An actuator which makes it possible to avoid adhesion of dust or the like to a driving force-transmitting member, wipe out the fear of stop or breakage thereof, and avoid leakage of dust or the like to the outside. Fixing blocks 26a, 26b are slidably provided via guide blocks 22a to 22d on guide rails 18a, 18b for constructing an actuator 10. Slits 88a, 88b are defined at gaps between a top cover 84 and side covers 82a, 82b. Seal members 94a, 94b are provided for each of the slits 88a, 88b. A forward end of one of the seal members 94b is engaged with a step section 104a or 104b of the other seal member 94a to close the slit 88a, 88b. The fixing blocks 26a, 26b penetrate and protrude through the slits 88a, 88b. The forward ends of the seal members 94a, 94b abut against wall portions of the fixing blocks 26a, 26b to close the gaps disposed at the passages into the inside of the actuator 10.

Abstract: A passage communication member is fitted in a first passage in a structural member, and has a head which is mounted in a slot in another structural member. The first passage in the structural member and a passage in the other structural member are held in communication with each other through a through hole that is defined in the passage communication member. Alternatively, a first engaging member is inserted in a recess defined in a structural member, and a second engaging member is retained in a slot in another structural member. When the first and second engaging members are coupled to each other by a fastening member, the structural members are firmly joined and fixed to each other.

Abstract: A guide mechanism has a linear guide rail, a guide block displaceable along the linear guide rail, and a roller carrier plate interposed between the linear guide rail and the guide block and having an array of rollers held in line-to-line rolling contact with a side surface of the linear guide rail. The rollers roll in line-to-line rolling contact with the side surface of the linear guide rail, thus reducing resistance to the movement of the guide block along the guide rail and minimizing wear on the rollingly contacting components.