Abstract: The present invention provides the ballpoint pen that precludes the possibility of the pipe portion bending at the joint thereof can be provided even if the outer diameter D is small. In the ballpoint pen having a ballpoint pen tip at a front end thereof, the ballpoint pen tip rotatably accommodating a ball at a front end of a pipe made of metal, an outwardly projecting pipe portion having a uniform thickness throughout the length thereof is arranged at a front end of the ballpoint pen tip, and if a length of the pipe portion is L, an outer diameter of the pipe portion is D, a relational expression "L/D.ltoreq.4.0" is satisfied.

Abstract: Ink and a follower advancing with consumption of the ink are stored directly in the inside of a barrel having a pen point at its forward end. An outer tail plug constituted by a closed-end cylinder is fitted to a rear outer surface of the barrel. An air course is formed between the rear outer surface of the barrel and an inner surface of the outer tail plug to communicate with the inside of the barrel through a rear end aperture portion of the barrel. At least one air hole is provided ahead of the rear end aperture portion of the barrel to make the air course communicate with the outside air.

Abstract: A penpoint assembly includes a penpoint which is made of a metal plate cut off at both side edges to form a taper toward the writing tip. A slit is provided extending from the front end of the writing tip to the vicinity of the rear end of the writing tip along the center line of the penpoint. The penpoint is bent at the writing tip to form small bent projections at both sides of the slit, the bent portion surrounding a small space. An ink guide core extends under the slit and communicates at the tapered portion of the ink guide core with the slit. A support member supports the ink guide core and penpoint. A writing instrument includes the penpoint assembly, the support member being integrally formed with an ink flow regulating portion, so that ink in an ink storage member in the rear portion of a penholder is guided to the writing tip through the ink guide core.

Abstract: A penpoint assembly includes a penpoint which is made of a metal plate cut off at both side edges to form a taper toward the writing tip. A slit is provided extending from the front end of the writing tip to the vicinity of the rear end of the writing tip along the center line of the penpoint. The penpoint is bent at the writing tip to form small bent projections at both sides of the slit, the bent portion surrounding a small space. An ink guide core extends under the slit and communicates at the tapered portion of the ink guide core with the slit. A support member supports the ink guide core and penpoint. A writing instrument includes the penpoint assembly, the support member being integrally formed with an ink flow regulating portion, so that ink in an ink storage member in the rear portion of a penholder is guided to the writing tip through the ink guide core.

Abstract: In a liquid-applying tip assembly in which the liquid-applying member is pushed to operate the valve to allow the liquid to flow to the liquid-applying member, the liquid-applying member is a plastic member which comprises: a plurality of ribs extending radially and axially from an axial core in such a manner as to form a plurality of axial liquid passageways therebetween. A barrier is provided between the valve and the cylinder of the tip assembly, the barrier having a hole whose diameter is slightly larger than the outside diameter of the liquid-applying member to control the flow of liquid.

Abstract: A ball-point pen tip provided with a tubular ink guide portion formed of metal. The ink guide portion is formed with radial projections extending radially inwardly produced by the pressing deformation of the metal tube. These projections define capillary channels between neighbouring projections and a ball seat at their radially oriented surfaces. An ink guide stem disposed in the tubular ink guide portion has one end in contact with at least one of the projections, and has the other end confronting with an ink supply stem inserted in a holder. The holder and the ink guide portion provide a socket of the pen tip. Such pen tip is applied to a ball-point pen which includes an ink reservoir adapted to be connected to said ink supply stem. Such ball-point pen employs an aqueous solution based low viscosity ink.