A side-knock type mechanical pencil comprising a body with a side-mounted knock button coupled to the body of the mechanical pencil and adapted to slidingly engage with a lead tube with a frustoconical hub for translating the motion of the knock button actuation to linear extension of the lead.

A side-knock type mechanical pencil comprising a body with a side-mounted knock button coupled to the body of the mechanical pencil and adapted to slidingly engage with a lead tube with a frustoconical hub for translating the motion of the knock button actuation to linear extension of the lead.

A stylus includes in a tubular casing a core body, a pressure detector that detects a pressure applied to the core body, a coupling fitted over the core body, the coupling transmitting the pressure to the pressure detector, and a core pressing controller that controls the coupling to press the core body axially in the tubular casing. The coupling includes a push bearer that bears a push from the core pressing controller, a presser having an axial end fitted in the pressure detector, a fitting region fitted over a portion of the core body remote from a pen tip end of the tubular casing, a receptacle in which another end of the presser remote from an axial end thereof is axially movably housed, and an elastic member disposed in the receptacle, the elastic member biasing the other end of the presser resiliently toward an axial pen tip end of the receptacle.

A side-knock type mechanical pencil comprising a body with a side-mounted knock button coupled to the body of the mechanical pencil and adapted to slidingly engage with a lead tube with a frustoconical hub for translating the motion of the knock button actuation to linear extension of the lead.

A side-knock type mechanical pencil comprising a body with a side-mounted knock button coupled to the body of the mechanical pencil and adapted to slidingly engage with a lead tube with a frustoconical hub for translating the motion of the knock button actuation to linear extension of the lead.

A barrel assembly according to an embodiment includes one barrel having an annular engaging projection; and another barrel having an engaging projection that protrudes toward the annular engaging projection of the one barrel, wherein the engaging projection of the other barrel has an engaging edge that protrudes in a direction of engagement, the engaging edge further has a protruding molded part that further protrudes from the engaging edge in the direction of engagement, and the protruding molded part of the engaging edge of the other barrel engages with the annular engaging projection of the one barrel.

A barrel assembly according to an embodiment includes one barrel having an annular engaging projection; and another barrel having an engaging projection that protrudes toward the annular engaging projection of the one barrel, wherein the engaging projection of the other barrel has an engaging edge that protrudes in a direction of engagement, the engaging edge further has a protruding molded part that further protrudes from the engaging edge in the direction of engagement, and the protruding molded part of the engaging edge of the other barrel engages with the annular engaging projection of the one barrel.

An anti-rotation mechanism for a retractable eraser or other stick-like object for use with a writing instrument that utilizes locking elements to prevent the inadvertent retraction or extension of the eraser when pressure is applied to the eraser during the erasing operation.

A mechanical pencil includes a barrel extending in a longitudinal direction, a lead-propelling mechanism, a lead reservoir, a side button, and an eraser-propelling mechanism having a helical cam. The lead-propelling mechanism, the lead reservoir, the eraser-propelling mechanism, and the side button are at least partly housed inside the barrel. The lead-propelling mechanism, the lead reservoir, and the eraser-propelling mechanism are prevented from rotating about the longitudinal direction relative to one another and relative to the side button, and the side button is prevented from rotating about the longitudinal direction relative to the barrel.