To eliminate a roller at the return side, to facilitate the inspection and the cleaning, and to apply no unreasonable bending stress to a belt, by making a return side trough in a convex form to the upper side, and forming air films between the trough upper surfaces and the belt lower surfaces by injecting the air through plural small holes.
A conveyer belt 2 has an endless loop form, and a carrier side trough 3a has a convex bending surface to the lower side, while a return side trough 3b has a convex bending surface to the upper side. Air films 11 are formed between the upper surface of the carrier side trough 3a and the lower surface of the carrier side 2a of the conveyer belt 2, and between the upper surface of the return side trough 3b and the lower surface of the return side 2b of the conveyer belt 2, by the air injected from small holes 10. Since the end face form of the trough 3 has a center circular arc and both side linear parts, no bending stress is applied to both side parts of the conveyer side belt, and the return side trough 3b has a convex form to the upper side, no dust is accumulated between the return side belt and the troughs.
SHINODA MASAHITO
KITSUKI JUZO
