A combined eraser and suction cleaner for blackboards

摘要

935,807. Suction cleaners for blackboards. KWAN SHU MIN. May 2, 1962, No. 16874/62. Class 8(1). A blackboard eraser has eraser pads 14 mounted on one side of a casing 1 containing a fan 16 driven by an electric motor M which sucks the chalk dust removed by the pads through the opening 15 into the dust bag 18. The casing has a detachable cover plate 3 to provide access to the motor M and the batteries B, BSP1/SP.