A writing implement having a pen tip that can achieve excellent ink outflow performance and an increase in the effective area of a viewer portion allowing recognition of the writing direction, relative to the whole pen tip. The writing implement is a writing implement A which includes a pen tip 20 feeding ink from a writing implement body 10 and having a viewer portion through which the writing direction can be recognized, and is characterized in that the pen tip 20 is configured of, a least, a writing part 30 and a holding body 40 having a viewer portion 43, and the holding portion 40 has a sheet-shaped ink feeder 25 formed with slits or bumps on the surface and inside thereof to produce a capillary action.

An ink reservoir unit for a writing instruments using an ink reservoir tube with which low contamination can be achieved considering environmental problems; and a writing instruments using the same. The ink reservoir tube is composed of a composite material in which a raw material is layered on a paper substrate having paper as a substrate. One end section of the ink reservoir tube is coupled to a connection part formed on a writing member or a relay member that holds the writing member to constitute the ink reservoir unit for a writing instrument. In one preferred aspect, a locking means using a male thread formed on an outer peripheral surface is provided to the connection part to be connected to the ink reservoir tube, and the ink reservoir tube is coupled to the relay member that holds the writing member by the locking means.

A refill for writing implements has an ink reservoir tube (1) made of resin material and formed to be a straight cylinder and a writing tip (2) attached to one end of the ink reservoir tube (1), and a value of an expression of D.sup.4−(D−2t).sup.4 is selected to be 45 or greater, where D denotes an outer diameter of the ink reservoir tube (1) and t denotes a thickness of the ink reservoir tube (1). It is possible to secure the necessary storage amount of ink in the ink reservoir tube (1) without increasing the outer diameter thereof, and is also possible to provide a refill for a writing implement and a writing implement which allow one to keep writing comfortably without feeling of discomfort in writing.

Provided is a writing implement having a pen tip that can achieve excellent ink outflow performance and an increase in the effective area of a viewer portion allowing recognition of the writing direction, relative to the whole pen tip. The writing implement is a writing implement A which includes a pen tip 20 feeding ink from a writing implement body 10 and having a viewer portion through which the writing direction can be recognized, and is characterized in that the pen tip 20 is configured of, a least, a writing part 30 and a holding body 40 having a viewer portion 43, and the holding portion 40 has a sheet-shaped ink feeder 25 formed with slits or bumps on the surface and inside thereof to produce a capillary action.

In a writing tool 1, a front shaft 5 is detachably provided on a rear shaft 6 containing an ink absorbent body 7. A filling part 51 is provided on an outside surface of a rear part of the front shaft 5. The filling part 51 detachably fits to a fitted part 61 formed on an inside surface of an opening part of the rear shaft 6. The filling part 51 has an outward-facing pressure contact part 53 and a radially penetrating slit 54. The fitted part 61 has an inward-facing pressure contact part 63. The front shaft 5 and the rear shaft 6 are brought into a pressure contact with each other when the front shaft 5 and the rear shaft 6 are fitted to each other.

A nib holder. The nib holder includes a case having a nib insertion slot. A slider is contained within the case and has a plurality of connection pins and slider connection threads. A pusher is contained within the case and has a plurality of sliding slots. The pusher utilizes the sliding slots to establish a sliding connection to the slider via the slider's connection pins. A stopper is contained within the case. The stopper prevents horizontal motion of the pusher but permits vertical motion of the pusher. An adjuster has adjuster connection threads and utilizes the connection threads to mesh with the connection threads of the slider to establish a threaded connection. A nib is connected to the nib holder by insertion of the nib into the nib insertion slot and then rotation of the adjuster to raise the pusher vertically so that the nib is compressed between the pusher and the case.

A nib holder. The nib holder includes a case having a nib insertion slot. A slider is contained within the case and has a plurality of connection pins and slider connection threads. A pusher is contained within the case and has a plurality of sliding slots. The pusher utilizes the sliding slots to establish a sliding connection to the slider via the slider's connection pins. A stopper is contained within the case. The stopper prevents horizontal motion of the pusher but permits vertical motion of the pusher. An adjuster has adjuster connection threads and utilizes the connection threads to mesh with the connection threads of the slider to establish a threaded connection. A nib is connected to the nib holder by insertion of the nib into the nib insertion slot and then rotation of the adjuster to raise the pusher vertically so that the nib is compressed between the pusher and the case.

A nib for a valve-free free ink writing felt pen including a first end configured to deliver ink to a writing support and second end, opposite the first end, configured to be inserted in a nib receiving part of the valve-free free ink writing felt pen, the first end and the second end defining an axial direction of the nib, the nib having an external surface configured to cooperate with an internal surface of the nib receiving part, the external surface being configured to allow intake of air from the outside of a free ink tank, the valve-free free ink writing felt pen into the free ink tank and avoid ink leakage outside the free ink tank when cooperating with the internal surface of the nib receiving part. A valve-free free ink writing felt pen including a nib.

A nib for a valve-free free ink writing felt pen including a first end configured to deliver ink to a writing support and second end, opposite the first end, configured to be inserted in a nib receiving part of the valve-free free ink writing felt pen, the first end and the second end defining an axial direction of the nib, the nib having an external surface configured to cooperate with an internal surface of the nib receiving part, the external surface being configured to allow intake of air from the outside of a free ink tank, the valve-free free ink writing felt pen into the free ink tank and avoid ink leakage outside the free ink tank when cooperating with the internal surface of the nib receiving part. A valve-free free ink writing felt pen including a nib.

A nib holder. The nib holder includes a case having a nib insertion slot. A slider is contained within the case and has a plurality of connection pins and slider connection threads. A pusher is contained within the case and has a plurality of sliding slots. The pusher utilizes the sliding slots to establish a sliding connection to the slider via the slider's connection pins. A stopper is contained within the case. The stopper prevents horizontal motion of the pusher but permits vertical motion of the pusher. An adjuster has adjuster connection threads and utilizes the connection threads to mesh with the connection threads of the slider to establish a threaded connection. A nib is connected to the nib holder by insertion of the nib into the nib insertion slot and then rotation of the adjuster to raise the pusher vertically so that the nib is compressed between the pusher and the case.