A handheld implement, configured for example as a writing-instrument, having a shaft that has at least two shaft parts which are releasably connectable together via a plug-in coupling, which have a coupling unit at each front end of the shaft parts. Each coupling unit has a slide that is held immovably in a guide hole open on a face side in the associated shaft part and protrudes beyond the guide hole with a slide portion, the free end of the slide portion is formed as a latching fork that has a latching opening between two fork arms, that the slide portion bears a latching protrusion on its inner side behind the latching fork in the sliding direction, the coupling unit has a guide sleeve that encloses the slide and is guided movably in the guide hole counter to the restoring force of a spring- or rubber-elastic restoring element, and when the front ends, having the coupling units, of two shaft parts are pressed together, the latching fork of one coupling unit is latchable on the latching protrusion of the other coupling unit with at least one of the guide sleeves being pushed back.

A refill for a writing tool includes an ink containing tube that is made from a resin material and formed in a straight cylindrical shape, and a writing tip that is attached to an end of the ink containing tube. A press-fit portion, formed at the end of the ink containing tube, has a thickness being made thickened toward an inner circumferential surface and has an opening hole penetrating in an axial direction at a central portion of the press-fit portion. The writing tip or a relay member supporting the writing tip is press-fitted and attached to the press-fit portion. The refill for a writing tool can ensure a necessary and sufficient amount of ink stored without expanding an outer diameter of the ink containing tube, and sufficiently secure mechanical strength of an end portion, and a writing tool using the same can be provided.

A writing device can be configured to provide ink or a colored dye upon a piece of paper or other medium. Such a writing device can include a plurality of separately extendable writing elements and a housing with a plurality of holes upon a terminal end of the housing, each hole providing a dedicated outlet hole for one of the writing elements, the housing comprising one of an elliptical cross section, a circular cross section, and a rounded off square cross section.

A system and method for training correct positioning and pressure of digits on a marking instrument helps teach correct positioning and pressure of digits on a marking instrument, and a correct marking angle of the marking instrument relative to a reference plane. The system provides an electronic marking instrument having pressure sensors that detect the position and a predetermined, uniform pressure from three digits. The marking instrument further comprises tilt sensor that measures the marking angle of the marking instrument to determine whether a predetermined marking angle, between 45 to 90 degrees has been achieved. A determination of a predetermined pressure by the digits, and a predetermined marking angle of the marking instrument actuates a marking portion on the marking instrument to enable marking. However, a determination of an improper position and pressure of the digits and orientation of the marking instrument deactivates the marking portion to restrict marking.

The invention is embodied in a customizable writing instrument. In many respects, this customizable writing instrument is similar to an ordinary writing instrument. The big difference is that this customizable writing instrument comprises a removable second barrel. The removable second barrel (or sleeve) allows the guts of the instrument to remain housed in the first barrel so no writing instrument pieces get lost during customization of the second barrel.