Abstract: An improved writing implement comprising a barrel having multiple spiral grooves in the inner wall thereof so that a guide element of a carrier within the barrel having a single spiral thread thereon is selectively engaged with one of the multiple spiral grooves, a cap rotatably attachable to one end of the barrel including an insert portion having a protruding ring member projecting from the outer surface of the insert portion engageable with a corresponding ring groove in one end of the barrel, an extension on the cap protruding into the barrel and cooperatively engageable with the carrier so that rotation of the cap rotates and drives the carrier axially within the barrel for moving the lead inwardly or outwardly, and a tip having an insert end with multiple spiral projecting threads thereon cooperatively engageable with the sprial grooves in the barrel.

Abstract: A writing implement has a carrier for guiding a pencil lead forward and/or backward at both ends of a pencil barrel wherein the movement of the carrier is produced by rotating a cap to which a cap holder and a supporting member are integrally connected and the supporting member is provided with stop jaws for preventing an excess back movement of the carrier at the inner end of the supporting member.

Abstract: This invention relates to an improved mechanical pencil. More particularly, the invention concerns a mechanical pencil in which the back and forth movements of a writing implement are controlled by a carrier having a spiral guide travelling along the spiral grooves formed on the inside of the pencil barrel, the carrier being adapted to travel along the spiral grooves formed on the inside of the pencil barrel in response to the manual rotations of the cap holding one end of the supporting member.