US 4,281,939 AGranted

Mechanical pencil

OwnerYoshihide Mitsuyainventor

Life of this patent

Estimating the term…

Loading patent…

Abstract

A mechanical pencil wherein a lead is propelled through a lead insertion tube provided at the forward end of the pencil body by the propulsion of a lead sustaining and feeding mechanism consisting of a chuck and the like, the mechanical pencil also having a lead protective device wherein a thin film made of an elastic material, such as rubber, synthetic resin or the like, is provided over the whole length of the inner surface of the lead insertion tube so that the lead is permitted to pass therethrough with ease, the elastic thin film being adapted to have a relatively greater thickness at the forward end part of the lead insertion tube so as to form a lead sustaining portion, the elasticity of the lead sustaining portion precluding the lead from slipping out due to own weight when released from the lead sustaining and feeding mechanism thereby minimizing the loss of lead.

Claims1

Dependent claims

A mechanical pencil having a lead protective device, said pencil comprising:

a pencil body;
a lead insertion tube on the forward end of said pencil body and having a substantially uniform inner diameter;
a thin film of an elastic material, such as rubber, synthetic resin or the like, on the inner surface of said lead insertion tube, the portion of the thin elastic film on the forward end of the tube having a greater thickness than the thickness of the film on the remainder of said tube for frictionally engaging a lead for preventing it from falling out of said insertion tube;
and
a lead guide integral with said film at the rear end of said tube and projecting out of said tube and having a rearwardly diverging funnel shaped hole opening into the interior of the remainder of said film, the material of said lead guide extending forwardly over the outer surface of said tube and having a check flange on the forward end thereof around the outside of said tube functioning as a check for preventing said tube from falling out of the pencil body.

2 more elements

Dependencies are inferred from the claim text.