Pencil lead sharpener - comprises cylinder with inner abrasive surface against which tip of lead is rubbed to sharpen it

摘要

The sharpener consists of a cylindrical or conical chamber (1) with an abrasive inner surface (2) against which the lead is rubbed to give it a point or an edge. If the lead is rubbed round the inside of the container in a circular motion the lead is sharpened to a point, while a lengthwise reciprocating motion produces a chisel tip. In a variant of the design the chamber can have a funnel-shaped base leading to a detachable lower section in which the powder residue from the pencil leads can be collected and disposed of.The chamber can measure, for example, 50 mm high by 25 mm in diameter, and is especially suitable for propelling pencil leads which are extended by some 1.5 cm before sharpening. ADVANTAGE - Design simplicity and efficient in use.