AUTO ERASER FOR CHALK DUST

摘要

The wiper, when moved one way on the board, rotates a rotary wheel to transfer the rotary power with a belt to an axle shaft mounted with an elastic dust brush for dusting chalk powder on the wiper roller. a worm part of the shaft actuates a worm gear for its reduced speed rotation which in turn slows the rotation of a connecting shaft worm and another worm gear engaged with the wiper shaft to rotate the wiper. When moved in reverse, the rotary wheel rotates counter wise for the belt to rotate the brush to dust chalk powder on the wiper roller to be collected in the bottom collector. The counter rotation of the rotary wheel is interrupted by an one way bearing.