A ballpoint pen tip comprises: a ball having a diameter of 0.5 mm or less; and a tip body, wherein the tip body has a ball holding chamber, a rear hole, an ink flow hole, and an ink flow groove opening to the ball holding chamber, and not reaching the rear hole. A ratio of an ink consumption per 100 m of handwriting to a diameter of the ball is 200 mg/mm or more and 800 mg/mm or less, and when a front end of the ink flow groove is set as a start point and a position of 0.3 mm rearward from the front end of the ink flow hole is set as an end point, a volume of a first space in the ink flow hole and the ink flow groove from the start point to the end point is 0.02 mm.sup.3 or more.

A knock type pen including a housing, a lead which is received in the housing and has an end to which a nib is coupled, and a knock element which protrudes from top of the housing and is pushed, a regulating element which is rotatably installed on an outer circumference of the housing, and a locking element which is provided in the housing and moves up and down by rotation of the regulating element, wherein when the locking element moves up, a press of the knock element is limited by the locking element.

A knock type pen including a housing, a lead which is received in the housing and has an end to which a nib is coupled, and a knock element which protrudes from top of the housing and is pushed, a regulating element which is rotatably installed on an outer circumference of the housing, and a locking element which is provided in the housing and moves up and down by rotation of the regulating element, wherein when the locking element moves up, a press of the knock element is limited by the locking element.

A knock type pen including a housing in which a lead storing ink is received, a knock element which is placed moveably up and down in the housing, and has a button section protruding from an open upper side of the housing in an upper end part and a toothed protrusion coupled to a lower end part, and a rotary cam which is disposed between the lead and the knock element and rotatably placed in the housing, and has a guide protrusion which comes into contact with the toothed protrusion.

A knock type pen including a housing in which a lead storing ink is received, a knock element which is placed moveably up and down in the housing, and has a button section protruding from an open upper side of the housing in an upper end part and a toothed protrusion coupled to a lower end part, and a rotary cam which is disposed between the lead and the knock element and rotatably placed in the housing, and has a guide protrusion which comes into contact with the toothed protrusion.

A retractable pen includes a barrel, an ink cartridge, a limiting member, a shifting member and a deformable member. When the shifting member is moved relative to the limiting member between a first position and a third position, the ink cartridge can be moved from a retracted position to an extended position or from the extended position to the retracted position. When the ink cartridge is located at the extended position, the deformable member can be further compressed by between the shifting member and the ink cartridge, allowing the shifting member to be moved further from the third position to a second position closer to the ink cartridge. When the shifting member is located at the second position, the ink cartridge is continuously held to the extended position and pressed against a lead-out opening of the barrel without the risk of swaying when a user writes with the retractable pen.

A retractable pen includes a barrel, an ink cartridge, a limiting member, a shifting member and a deformable member. When the shifting member is moved relative to the limiting member between a first position and a third position, the ink cartridge can be moved from a retracted position to an extended position or from the extended position to the retracted position. When the ink cartridge is located at the extended position, the deformable member can be further compressed by between the shifting member and the ink cartridge, allowing the shifting member to be moved further from the third position to a second position closer to the ink cartridge. When the shifting member is located at the second position, the ink cartridge is continuously held to the extended position and pressed against a lead-out opening of the barrel without the risk of swaying when a user writes with the retractable pen.

Provided is a writing utensil with a pressurizing mechanism, wherein the cylinder is provided in such a manner that it comes into sliding contact with an outer peripheral part of the valve element and move back and forth, and an inner wall face of the cylinder is provided with a ventilating recess communicating with outside air, and an annular non-pressure contact face positioned on the rear side of the ventilating recess, and when the cylinder moves forward, the valve element is brought into pressure contact with the non-pressure contact face to seal the pressurizing chamber, and when the cylinder moves backward, the valve element is moved forward and separated from the non-pressure contact face such that the ventilating recess communicates with the pressurizing chamber.

Provided is a writing utensil with a pressurizing mechanism, wherein the cylinder is provided in such a manner that it comes into sliding contact with an outer peripheral part of the valve element and move back and forth, and an inner wall face of the cylinder is provided with a ventilating recess communicating with outside air, and an annular non-pressure contact face positioned on the rear side of the ventilating recess, and when the cylinder moves forward, the valve element is brought into pressure contact with the non-pressure contact face to seal the pressurizing chamber, and when the cylinder moves backward, the valve element is moved forward and separated from the non-pressure contact face such that the ventilating recess communicates with the pressurizing chamber.

The present disclosure relates to a knock type pen including a body in which a lead and a spring which provides an elastic force to the lead are received, and a knock section which is coupled to a rear end of the body and includes a knock body and a rotary cam to push the lead out of a tip of the body or receive the lead inside, wherein the knock type pen includes a cutout groove which extends in one direction along an axial direction of the body, a slit hole which extends along a downward direction from an upper end of the cutout groove, an insert hole which is formed in a direction perpendicular to the slit hole from the upper end of the cutout groove, and a locking section which moves up and down along the slit hole.