Patent ID: 7255507

Claim:
A capless retractable sealed writing instrument comprising: an elongated marker housing with an axial opening; a marker reservoir having a marker nib and held within a marker carrier mechanism within the marker housing, the marker carrier mechanism operative to linearly move the marker reservoir and marker nib within the marker housing, to extend and retract the marker nib through the axial opening in the marker housing; a sealing means having a sealing chamber, a wiper seal piece and a forward seal piece; and said chamber having a peripheral wall defining a hollow bore, the chamber disposed coaxially with said reservoir, whereby the reservoir extends at least partially into said hollow bore with the wiper seal piece sealing against the reservoir, and wherein the forward seal piece extends from an annular flange and includes a flexible central membrane with at least one slit there through that does not extend to the annular flange forming at least two flexible sealing flaps.