Patent ID: 6370720
Filing Date: 2002-04-16
Classification: B43L

Abstract:
An apparatus for automatically erasing a blackboard, the blackboard erasing apparatus comprising:a housing having an opening toward a blackboard plate, an upper support plate and a lower support plate which are fixed to walls of the housing; variable contact means having right and left eccentric axles rotatably mounted between the upper support plate and the lower support plate, an upper rectangular variable plate having a round hole through which the right eccentric axle protrudes, a lower rectangular variable plate having an elliptical hole through which the left eccentric axle protrudes, a first cover member vertically mounted between the upper variable plate and the lower variable plate and covering the eccentric axles, and a second cover member vertically mounted between the upper variable plate and the lower variable plate, the second cover member having two protrusions protruded outwardly from both front end portions of the second cover member; right erasing means having a right cylindrical brush and two right wiper members; and left erasing means having a left cylindrical brush and two left wiper members, the brushes rotatably mounted between the upper and lower variable plates and positioned within the second cover member, the wiper members being formed in a wedge shape and positioned within the protrusions of the second cover member.