Patent ID: 8042679

Claim:
A belt cleaner for removing the leavings of conveying material on the surface of a conveyor belt during the return movement thereof comprising a scraper ( 5 ), a holder ( 6 ) holding said scraper and tension means; said holder ( 6 ) providing a pair of holding walls ( 11 , 12 ) extending in the transverse direction of the belt and a holding groove ( 13 ) formed between said walls which is curved gradually from the both side portions to the central portion thereof in the lengthwise direction of the belt, said tension means being disposed for pushing said holder ( 6 ) to rotate about an axis (A) extending in the transverse direction of the belt so that said holder ( 6 ) is turned upward to its standing position, and said scraper ( 5 ) comprising a resilient blade which is yieldingly deformable in such manner as to be curved from the linear state to an arch shape so that said scraper ( 5 ) is curved in an arcuate shape to form a distance (L) between the central portion and the both side portions thereof with respect to the lengthwise direction of the belt when said scraper ( 5 ) is held in said holding groove ( 13 ), characterized in that: shape shifting means ( 20 ) is provided in said holding groove ( 13 ) for transforming said scraper ( 5 ) into a desired curved configuration selected from among plural curved configurations changing said distance (L) thereby the scraper ( 5 ) is held to keep said selected curved configuration; wherein said front holding wall ( 11 ) is curved arcuately with a radius of curvature Rw 1 and said rear holding wall ( 12 ) is curved arcuately with a radius of curvature Rw 2 under the conditions of Rw 1 >Rw 2 so that the width W 1 at the central region and the width W 2 at the both side regions of said holding groove ( 13 ) are formed to be W 2 >W 1 thereby the both side ends of the scraper ( 5 ) are allowed to move between the holding walls ( 11 , 12 ); wherein said shape shifting means ( 20 ) comprises one or more filler plates ( 21 , 21 ) ( 26 ) of flexible material having thick portions ( 21 a ) ( 26 a ) and a thin portion ( 21 b ) ( 26 b ) which are inserted between the scraper ( 5 ) and one of the holding walls ( 11 , 12 ) so that said distance (L) of the scraper ( 5 ) is allowed to be selected from two different distances (L 1 or L 3 ) and (L 2 or L 4 ) that are defined under the conditions of L 1 <L 2 and L 3 <L 4 by selecting the positions of the filler plate to be inserted in the holding groove ( 13 ), whereby the scraper ( 5 ) is curved along the inner surface of the front holding wall ( 11 ) and is held in the arcuate configuration having said distance (L 1 or L 3 ) when the filler plate is inserted between the scraper ( 5 ) and the rear holding wall ( 12 ), and the scraper ( 5 ) is curved along the inner surface of the rear holding wall ( 12 ) and is held in the arcuate configuration having said distance (L 2 or L 4 ) when the filler plate is inserted between the scraper ( 5 ) and the front holding wall ( 11 ).