A dual twist structure, an object ejecting device including the same, and a structure for sealing the same, the dual twist structure including: a housing configured to accommodate a content cartridge therein and having a cam groove provided at a tip thereof; a sleeve coupled to and fitted with the content cartridge and having a cam protrusion formed on an outer portion thereof; and a tubular operation body having a twist cam groove into which the cam protrusion is slidably fitted, and a cam pin protruding and configured to move to a position misaligned with the twist cam groove by being guided by the cam groove, in which the dual twist structure has the two cam grooves.

A tail plug to be attached to a tail end of a shaft part of a writing instrument includes an inner plug that is fitted into the shaft part and an outer plug that is coupled with the inner plug. The inner plug has a first opening through which a fluid can flow in an axial direction of the shaft part; the outer plug has a second opening through which a fluid can flow in the axial direction of the shaft part, and at least one of the first opening and the second opening are configured to be closed when the outer plug and the inner plug are coupled with each other.

A slide-type writing instrument having a drying-prevention device includes: a pen housing (10); an ink holder (30) disposed in the pen housing (10); a sealing member (40) configured to prevent a drying phenomenon of ink on a pen tip (31); a spring (50) configured to effect elastic support between the sealing member (40) and the ink holder (30); a guide member (60) configured to guide the sealing member (40) when the ink holder (30) is advanced or retreated; and a cam protrusion (70) configured to be responsible for a guiding function of moving the guide member (60). The sealing member includes a soft tube formed of a soft material and a hard tube formed of a hard material and in the shape of a hollow tube to externally surround the soft tube, and the soft tube and the hard tube form a dual cross-section structure.

A slide-type writing instrument having a drying-prevention device includes: a pen housing (10); an ink holder (30) disposed in the pen housing (10); a sealing member (40) configured to prevent a drying phenomenon of ink on a pen tip (31); a spring (50) configured to effect elastic support between the sealing member (40) and the ink holder (30); a guide member (60) configured to guide the sealing member (40) when the ink holder (30) is advanced or retreated; and a cam protrusion (70) configured to be responsible for a guiding function of moving the guide member (60). The sealing member includes a soft tube formed of a soft material and a hard tube formed of a hard material and in the shape of a hollow tube to externally surround the soft tube, and the soft tube and the hard tube form a dual cross-section structure.

The adaptation of a pocket-size pen for use by a person is provided. The pen includes a cap with internally configured male threads, and a body. The body includes a barrel with externally configured and spaced apart first set of female threads, and second set of female threads. The barrel is hollow inside with a top opening for receiving a full-sized standard ink source. The male threads of the cap engage the second set of female threads of the pen body for closing a writing tip and reducing the length of the pen for storage in the pocket of a user. The male threads of the cap engage the first set of female threads of the body for transforming the pen into an extended-length pen similar in length to a conventional pen and revealing the writing tip for comfortable writing using the pen.

A friction body is configured to discolor handwriting written with a thermochromic ink with frictional heat. The friction body includes a viscoelastic body, and has a Shore A hardness (based on JIS K 7215) immediately after start of contact of an indenter point of from 55 to 95.

A friction body is configured to discolor handwriting written with a thermochromic ink with frictional heat. The friction body includes a viscoelastic body, and has a Shore A hardness (based on JIS K 7215) immediately after start of contact of an indenter point of from 55 to 95.

Disclosed is a pen for writing, referred to as a palm pen herein because the body of the pen fits into the palm of a human hand. The palm pen can include a spherically shaped body, and an ink delivery system. The ink delivery system can include a tip having an end connected to the body and an opposite end comprising a nib, an ink conduit having an end coupled to the nib within the tip and an opposite end extending inside the body, and a first ink cartridge fluidly coupled with the opposite end of the ink conduit and contained within the body. The ink delivery system can additionally include a cartridge holder having an active cartridge slot for the first ink cartridge and cartridge storage slots for storage of additional ink cartridges.

Disclosed is a pen for writing, referred to as a palm pen herein because the body of the pen fits into the palm of a human hand. The palm pen can include a spherically shaped body, and an ink delivery system. The ink delivery system can include a tip having an end connected to the body and an opposite end comprising a nib, an ink conduit having an end coupled to the nib within the tip and an opposite end extending inside the body, and a first ink cartridge fluidly coupled with the opposite end of the ink conduit and contained within the body. The ink delivery system can additionally include a cartridge holder having an active cartridge slot for the first ink cartridge and cartridge storage slots for storage of additional ink cartridges.

A compact writing instrument includes a barrel and a cap. A majority of a length of the barrel and a writing element carried thereby may be received by the cap when the barrel and the cap are placed in a stored position, providing a compact stored arrangement. The cap may be secured to the barrel in a writing arrangement that extends a length of the writing instrument significantly; for example, to a conventional writing instrument length. Engagement features of the cap and barrel may include steep threads that enable the cap to be assembled with and disassembled from the barrel with one rotation (360°) or less. A clip on the cap may include a closed end that defines a receptacle, with the closed end and receptacle extending beyond a corresponding end of the cap. In addition, the closed end and receptacle may extend partially over the corresponding end of the cap.