US 4,299,506 AGranted

Mechanical pencil

AssigneePentel Kabushiki Kaisha

InventorJunichi Hashimoto

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Abstract

A mechanical pencil is disclosed which comprises a casing having a ferrule at its tip end and having an axially extending central bore formed therein, and a lead-containing sleeve fitted into the central bore and capable of containing a plurality of leads. The mechanical pencil includes a lead guide pipe which is mounted in the ferrule and extending into the central bore. A feed roller is rotatably mounted within the central bore between the lead guide pipe and the lead-containing sleeve for feeding a lead from the sleeve into the lead guide pipe. The feed roller has a frusto-conical configuration with its axis disposed at an angle with respect to the axis of the central bore, and is peripherally provided with a helical rib, which is adapted to engage the periphery of lead. A rotation is externally imparted to the shaft of the feed roller, thereby rotating it to feed a given length of the lead forward.

Claims13

Dependent claims

A mechanical pencil comprising:

a casing having a ferrule at its one end and having a central bore which extends axially thereof;
a lead-containing sleeve capable of containing a plurality of leads and fitted into the central bore and having its rear end closed by a cover which is detachably mounted on the casing, the front end of the sleeve having a narrowed portion having an opening in alignment with the sleeve axis and a diameter slightly greater than that of the lead;
a lead guide pipe mounted in the ferrule so as to be aligned with the axis of the central bore and slidably holding the lead;
lead feed means located intermediate the lead guide pipe and the lead-containing sleeve and including at least one lead feed roller having a helical rib on its periphery for engagement with the outer peripheral surface of the lead, said feed roller having a frusto-conical configuration with its axis located in a plane which includes the axis of the lead guide and which is disposed at an angle with respect to the axis of the lead guide, the feed roller being supported so as to be slidable in its axial direction;
drive means for rotating the lead feed roller about its axis;
and operating means mounted on the outside of the casing for operating the drive means.

3 more elements

Dependencies are inferred from the claim text.