Abstract: An instrument includes a holder for holding a medium, a cap capable of covering a tip end portion of the medium, and a knock member provided to be capable of knocking to attach and detach the cap. The cap is connected to the knock member via a rotational transform mechanism. The rotational transform mechanism advances the cap in accordance with one knock of the knock member in the axial direction, the rotational transform mechanism rotates the cap around an axis parallel to the axial direction, then retreats the cap, so that the state in which the cap covers the tip end portion of the medium and the state in which the cap allows the tip end portion of the medium to be exposed are switchable for each knock of the knock member.

Abstract: An instrument includes a holder for holding a medium, a cap capable of covering a tip end portion of the medium, and a knock member provided to be capable of knocking to attach and detach the cap. The cap is connected to the knock member via a rotational transform mechanism. The rotational transform mechanism advances the cap in accordance with one knock of the knock member in the axial direction, the rotational transform mechanism rotates the cap around an axis parallel to the axial direction, then retreats the cap, so that the state in which the cap covers the tip end portion of the medium and the state in which the cap allows the tip end portion of the medium to be exposed are switchable for each knock of the knock member.

Abstract: A click-type writing implement with reduced diameter by suppressed swerving of writing element during advancing and with improved easiness of assembling and improved ornamental appearance, comprising manipulator pieces on outside; actuator pieces respectively advanced or retracted by the manipulator pieces; a main shaft arranging writing elements as forward and rearward slidable; springs respectively applying rearward stress on the actuator pieces. The each actuator piece has a first and second projecting portions, which protrude laterally respectively at forefront portion and at a rearward portion distanced from the forefront portion. The main shaft has an inner face comprised of a small-internal-diameter portion in vicinity of rearmost retracted position of the second projecting portion. The second projecting portion has a cam face for creating outward propelling force when two of the second projecting portions axially bear with each other.