Patent ID: 6033141
Filing Date: 2000-03-07
Classification: B43K

Abstract:
A capless retractable sealed writing instrument comprising:an elongate marker casing with an axial opening,a marker cartridge having a marker nib and held within a marker carrier mechanism within the marker casing, the marker carrier mechanism operative to linearly move the marker cartridge and marker nib within the marker casing, to extend and retract the marker nib through the axial opening in the marker casing,and a single piece seal held within the marker casing proximate to the open end of the marker casing, the single piece seal having a generally annular rim held within the marker casing in a plane generally perpendicular to a longitudinal axis of the marker casing, and a concave flexible disk attached to and within a circular area defined by the annular rim, the concave disk having a cross-section in the form of an arc with an apex of the arc oriented to face the marking nib when the marking nib is in a fully retracted position within the marker casing, and a full diameter slit through the radial center and cross-section of the concave disk, from one point of the internal diameter of the annular rim to a radially opposite point, to form cooperative sealing disk halves which are deflectable away from the slit to allow passage of the marker nib through the seal upon linear movement of the marker cartridge and marker nib by the marker carrier mechanism to an extended position, and which return to a concave sealed configuration upon retraction of the marker nib into the marker casing.