Abstract: The device of the invention for regulating the passage of adherent or tacky materials to an enclosure comprises: a main hollow body with an access hole susceptible of being covered by a locking cover, and a lower opening; a swinging locking cover, susceptible of adopting a closed position, covering the access hole, and an open position, being swung onto one of the inner walls of the main body; cleaning means for the outer face of the cover, comprising a rotating cleaning disc shiftable between an inoperative position, allowing the passage of materials to the main body, and an operative cleaning position, the disc being juxtaposed to the outer face of the cover when the latter adopts the open position, removing by friction the material residues adhered to the face as the disc rotates.