Mechanical pencil

摘要

A mechanical pencil includes a lead engaging collet biased rearwardly, a collet receiver tube having a tapered guide face and rolling elements mounted between the tapered guide face and the collet for inducing a clamping force against a writing lead. The pencil includes a device for advancing the collet receiver tube and the collet toward a pencil tip and then permitting the collet receiver tube alone to move rearwardly. This assures that the inner elements will step the lead an increment from the pencil tip for writing purposes.