Patent ID: 6607325
Filing Date: 2003-08-19
Classification: B43K

Abstract:
A writing instrument comprising:an ink chamber formed inside a main body of the writing instrument; a writing element provided on a front end portion of the main body of the writing instrument; a reservoir chamber which is formed between the ink chamber and the writing element and communicates with the atmosphere and with the writing element; a plurality of walls which partitions the reservoir chamber and the ink chamber and further partitions the ink chamber into a plurality of small chambers in the axis direction; and an ink supply member which penetrates the plurality of walls and supplies ink from the ink chamber to the writing element, wherein a through hole through which the ink supply member passes is formed at a center portion of each of the walls, and a circular gap capable of holding the ink by capillary force is formed between an inner periphery of the through hole formed in each of the walls and an outer periphery of the ink supply member, the ink supply member is a rod-shaped member composed of a porous material, and has an ink-permeable surface on its periphery, and gas-liquid exchange between the reservoir chamber and the ink chamber and between adjacent ink chambers is performed only through the circular gap formed in each of the walls.