Abstract: Provided is an ink introducing tube which realizes a stabilized ink supply from an ink tank located at the rear portion of a felt pen into a tip at the front end thereof, and a writing instrument incorporating it. On the inner peripheral wall of an ink introducing tube through which an ink tank is communicated with a tip located at the front end, a plurality of protrusions are formed to provide therebetween a passage for downward flow which utilizes the capillary action of the protrusions, and the interior space of the ink introducing tube which is surrounded by the tips of the plural protrusions is formed as a large space so that the capillary action can take place. Thus, the flow of air to the ink tank moves upwardly through the interior space while changing into air foam during the ascent, whereas the ink flows downward while being retained between the protrusions. Therefore, replacement of the ink by the air can be performed smoothly whereby ink blobbing is prevented and flawless writing is realized.

Abstract: There is provided a pen in which ink is supplied steadily from an ink tank to a pen point. Ink in an ink tank 6 is supplied to a pen point 5 through a slender tube portion 4A of an ink introducing slender tube 4. Excess ink can be kept by a stuffing member 7 that is in contact with a portion in which the ink introducing slender tube 4 and the pen point 5 are connected to each other and a gap 8 provided in the connecting portion.

Abstract: A longer lifetime of a writing instrument having a fibrous writing tip is attained by replacement of a refill, which comprises a body and a wadding impregnated with an ink. The body has closed front and rear ends. The front end may be sealed with a thin sealing film. The body of the writing instrument comprises a pen barrel 1 having a hollow therein, and a writing tip having at its rear end a pointed member protruding therefrom. The refill is fitted into the hollow with the open end whose sealing sheet has been peeled off ahead or with the front end ahead, and is slid to a position where a second stopper abuts against the rear end of the pen barrel. At that time, the rear end of the writing tip is caused to enter the interior of the refill through its open end free from the sealing sheet. Alternatively, the front end of the refill is pierced by a pointed member to cause the rear end of the writing tip to plunge into the wadding.