| 摘要 |
PURPOSE:To automatically absorb the loosening of a chain by a method in which the returning side of a chain to raise the rake of a dust remover is pressed by a rotary tensing part, and the returning rail in the inside of the pressed portion is expansively curved. CONSTITUTION:A chain 1 with a rake 2A is engaged between upper and lower sprockets 15, and a rotary tensing part 30 having a weight 33 inside is attached through an arm 35 to the chain 1 to form a dust remover. In the normal state of the chain 1 without loosening, reaction R to be produced by the weight W of the tensing part 30 is balanced with the tension of the chain 1. In the loosened state of the chain 1, the chain 1 is bent toward the inside return rail 38 side expansively curved to absorb the loosening of the chain 1. |
