A soft-member attachment structure includes an attachment hole provided through a rear end portion of a barrel. The barrel configures a thermochromic writing instrument, along a longitudinal central axis and having an inner circumferential surface between two openings located at an upper end and a lower end; an attachment portion located under a large diameter portion of a soft member used for a thermochromic change and having a diameter being smaller than a diameter of the large diameter portion and allowing insertion into the attachment hole; a straight internal hole provided along a longitudinal central axis of the soft member and opening at least at a lower end of the soft member; and a rod-like inner core having an outer diameter allowing insertion into the internal hole, a length to be placed within the internal hole, and an outer circumferential surface contacting an inner circumferential surface of the internal hole. The attachment portion is inserted into the attachment hole and the inner core is inserted into the internal hole to attach the soft member to the attachment hole.

A manual device including a first portion and a second portion. The second portion being at least partially fitted into the first portion and being moveable in translation relative to the first portion. The first portion having a first distal end while the second portion has a second distal end opposite the first distal end. The second portion also includes a locking device designed to prevent the first portion from moving in translation relative to the second portion only when, considered in the direction of gravity. The first distal end is arranged above the second distal end, and the locking device includes a chamber and a ball or equivalent accommodated in the chamber. The chamber is provided only in the second portion.

A manual device including a first portion and a second portion. The second portion being at least partially fitted into the first portion and being moveable in translation relative to the first portion. The first portion having a first distal end while the second portion has a second distal end opposite the first distal end. The second portion also includes a locking device designed to prevent the first portion from moving in translation relative to the second portion only when, considered in the direction of gravity. The first distal end is arranged above the second distal end, and the locking device includes a chamber and a ball or equivalent accommodated in the chamber. The chamber is provided only in the second portion.

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 manual device including a first portion and a second portion. The second portion being at least partially fitted into the first portion and being moveable in translation relative to the first portion. The first portion having a first distal end while the second portion has a second distal end opposite the first distal end. The second portion also includes a locking device designed to prevent the first portion from moving in translation relative to the second portion only when, considered in the direction of gravity. The first distal end is arranged above the second distal end, and the locking device includes a chamber and a ball or equivalent accommodated in the chamber. The chamber is provided only in the second portion.

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 soft-member attachment structure includes an attachment hole provided through a rear end portion of a barrel. The barrel configures a thermochromic writing instrument, along a longitudinal central axis and having an inner circumferential surface between two openings located at an upper end and a lower end; an attachment portion located under a large diameter portion of a soft member used for a thermochromic change and having a diameter being smaller than a diameter of the large diameter portion and allowing insertion into the attachment hole; a straight internal hole provided along a longitudinal central axis of the soft member and opening at least at a lower end of the soft member; and a rod-like inner core having an outer diameter allowing insertion into the internal hole, a length to be placed within the internal hole, and an outer circumferential surface contacting an inner circumferential surface of the internal hole.

A manual device including a first portion and a second portion. The second portion being at least partially fitted into the first portion and being moveable in translation relative to the first portion. The first portion having a first distal end while the second portion has a second distal end opposite the first distal end. The second portion also includes a locking device designed to prevent the first portion from moving in translation relative to the second portion only when, considered in the direction of gravity. The first distal end is arranged above the second distal end, and the locking device includes a chamber and a ball or equivalent accommodated in the chamber. The chamber is provided only in the second portion.