Conveyor, comprising a number of supporting bodies arranged successively in an array in order to form transporting positions for objects for transporting between two successive supporting bodies, wherein the form of the supporting bodies is suitable for urging the objects into a transverse position relative to the direction of movement. The dielectric layer defines a trench having both a wide portion and a narrow portion. While the substrates are within the chamber, they are simultaneously exposed to one or more of H, F and Cl to remove native oxide. A retention unit retains releasably the movable hinge leaf in the cutter concealing position when the latter is further disposed in the retaining position on the hinge pin. Downward force applied to the switch transmits the force through the inner shaft, and causes downward motion of a pusher plate attached to the end of the inner shaft.