Patent ID: 8813969

Claim:
A spiral module ( 1 ) for mounting one after another to form a spiral or screw guide along a concave inner surface of a perforated sieving deck ( 2 ) of a trommel screen to transport a charge forward through the trommel screen, the spiral module comprising: an extended flat part ( 5 ) that contacts and transports the charge along the sieving deck of the trommel screen: first and second mounting fittings ( 9 , 9 ′) connected to the extended flat part for coupling the spiral module with hole openings ( 3 ) formed in the sieving deck, wherein the extended flat part ( 5 ) includes two principal surfaces ( 6 a , 6 b ) that face away from each other, two long edges ( 7 a , 7 b ) and two short edges ( 8 a , 8 b ), wherein the first and second mounting fittings ( 9 , 9 ′) mount the spiral module standing onto the inner surface of the sieving deck such that the flat part ( 5 ) extends toward a center of the trommel screen where one ( 7 a ) of the two long edges faces the center of the trommel screen and the other long edge ( 7 b ) faces the sieving deck of the trommel screen, wherein in order to facilitate removal and adjustability of the spiral module, the spiral module further comprises: a first attachment means ( 10 ) that connects each of the first and second mounting fittings ( 9 , 9 ′) to the flat part and enables rotatable adjustment and locking of the first and second mounting fittings ( 9 , 9 ′) into different angular positions relative to a longitudinal axis of the extended flat part ( 5 ), wherein each of the first and second mounting fittings ( 9 , 9 ′) are rotatable about an axis of rotation (C) that is perpendicular to sieving deck when the spiral module is mounted to the sieving deck; and a second attachment means ( 20 ) supported by each of the first and second mounting fittings ( 9 , 9 ′) to face towards the sieving deck and located at a radial distance (E) from the axis of rotation (C) of the first and second mounting fittings, wherein each of the first and second mounting fittings are rotatable about the axis of rotation to position the second attachment means at different angular positions relative to the longitudinal axis of the extended flat part, thereby allowing the second attachment means to be selectively connected with the hole openings in the sieving deck.