Patent ID: 7128488
Filing Date: 2006-10-31
Classification: B43K

Abstract:
1. An instrument comprising: a holder for holding a medium; a cap capable of covering a tip end portion of the medium; an operating member provided to be capable of knocking with respect to the holder to attach and detach the cap; and a rotational transform mechanism connecting the cap to the operating member; wherein the rotational transform mechanism advances the cap in accordance with one knock of the operating member in an axial direction, the rotational transform mechanism then rotates the cap around an axis parallel to the axial direction, and then retreats the cap; and wherein with each knock of the operating member, a state in which the cap covers the tip end portion of the medium and a state in which the cap allows the tip end portion of the medium to be exposed are switchable, and wherein said rotational transform mechanism comprises a knock cam connected to said operating member and unrotatable but movable in the axial direction in a slide axial hole provided in the holder, a cam body provided on an inner peripheral surface of the slide axial hole and having a cam surface facing to a front and inclined in the axial direction, a rotary cam connected to said cap and movable in the axial direction with respect to the slide axial hole inside the slide axial hole, and an elastic member for biasing the rotary cam rearward, wherein the knock cam has a cam surface facing to the front and inclined in the axial direction, and rotation of the rotary cam is guided by the cam surfaces of the knock cam and the cam body.