JPH0615714Y2 - Synthetic resin pen body - Google Patents

Description

TECHNICAL FIELD The present invention relates to a synthetic resin pen body. More specifically, the cross-sectional shape is a ring and a large number of protrusions extending from the inner edge of the ring toward the axis, one of the protrusions extending to the axis and having a circular small cross-section at the tip. The present invention relates to a synthetic resin pen body provided with a core body having a protrusion.

2. Description of the Related Art Conventionally, in a cross-sectional shape of a synthetic resin pen body, a plurality of protrusions (radial ribs) are joined at the center from the inner edge of the ring, and an independent groove type in which a plurality of independent radial ink grooves are provided between the protrusions ( Various proposals have been made, such as JP-A-53-138535) and the communication groove type in which the protrusions do not reach the center and the ink grooves communicate with each other (JP-B-55-7418).

Problems to be Solved by the Invention The conventional groove type of the conventional synthetic resin pen body is advantageous in terms of abrasion resistance in addition to a writing feel that is responsive, but one portion of the ink passage may be deformed or It is clogged and closed due to the cause, and tends to cause variations in ink outflow and directionality during writing.On the other hand, the communication groove type has good ink followability, and it is difficult to cause directionality during writing. There was a disadvantage in comparison with the former in terms of the writing feel and the wear resistance of the central part.

The present invention utilizes the advantages of both of the above-mentioned conventional pen bodies, has good ink followability, has a writing feel and abrasion resistance with a feeling of response, and is an ink dropback when the pen body is left facing upward. It is intended to provide a synthetic resin pen body that does not include

Means for Solving Problems The present invention will be described below with reference to the drawings (FIGS. 1 to 4).

The synthetic resin pen body 1 of the present invention comprises a ring 2 and a number of protrusions 3 extending from the inner edge of the ring toward the axis, and a plurality of protrusions extending from the inner edge of the ring toward the axis at equal intervals. One of them extends to the shaft center, and the rest is a protrusion 3 whose tip does not reach the shaft center, and the core body 3 of the shaft center of the one protrusion.
No. 1 has at least three circular small protrusions in a cross section, and is required to have an ink passage 4 formed by a gap between the protrusions and between the circular small protrusions 311 of the core body 31 in the axial direction. And

Action The core body 31 reaching the shaft center contributes to improving the abrasion resistance of the writing tip in addition to the feeling of handwriting, and the periphery of the core body 31 of the shaft center is more axial than the inner ring edge. A plurality of extending ink passages 4 are extracted, and the ink passages communicate with each other, and the capillary force around the core body 31 is increased depending on the uneven cross-sectional shape of the core body 31 having the circular small protrusions 311. The ink is concentrated in a centripetal manner to improve the ink outflow from the writing tip. Further, the core body 31
The enhancement of the capillary force in the periphery suppresses the occurrence of defective ink outflow due to the ink being retained at the writing tip even when the writing tip is left facing upward.

Example The pen body 1 of the present invention having the above-described configuration is a known manufacturing method, for example, the manufacturing method described in Japanese Patent Publication No. 49-2132 and Japanese Patent Publication No. 53-27973 according to the invention of the present applicant, that is, Molten thermoplastic resin is extruded from a die having a plurality of holes arranged close to each other to form a plurality of filaments, and the filaments are mutually fused in a state in which the surfaces of the filaments have a fusible property. It can be effectively manufactured by a method of manufacturing a pen body in which a space serving as an ink conducting path which is not contacted and fused is formed in the longitudinal direction while being contacted and fused.

A series of rod-shaped bodies manufactured by the above method is cut into a predetermined size, and one end thereof is ground into a tapered shape for practical use.

1 to 4 are sectional views showing a specific example of the pen body 1 of the present invention obtained by the above-mentioned manufacturing method.

Effect of the Invention The pen body 1 of the present invention is a communication groove type pen body, but has the core body 31 at the shaft center portion, which improves the abrasion resistance of the pen tip portion in addition to the feeling of writing. Moreover, since the core body 31 has a cross-sectional shape having at least three circular small protrusions, the capillary force around the core body 31 is enhanced and the ink is concentrated on the shaft center portion from the writing tip. The ink can be effectively discharged, and an appropriate ink is always discharged without causing writing failure due to ink dropback when the writing tip is left in an upward state. Further, it does not cause poor ink followability due to clogging of the ink passage 4 that is often arranged in an independent groove type pen body and poor directionality at the time of writing, and it is a low viscosity ink and a relatively high viscosity pigment ink. It is effective as a pen for writing instruments using.

[Brief description of drawings]

1 to 4 are cross-sectional views of the synthetic resin pen body of the present invention. 1 ... Pen body, 2 ... Ring 3 ... Projection part, 31 ... Core body 311 ... Circular small protrusion, 4 ... Ink passage

Claims (1)

[Scope of utility model registration request] 1. A synthetic resin pen body having a cross-sectional shape consisting of a ring and a large number of protrusions extending from the inner edge of the ring toward the axis, and a plurality of pen bodies extending toward the axis from positions at equal intervals on the inner edge of the ring. One of the protrusions extends to the axis, and the rest is a protrusion whose tip does not reach the axis, and the core of the axis of the one protrusion has at least three circular small portions in cross section. A synthetic resin pen body having projections and having an ink passage formed in the axial direction between the projecting portions and between the circular small projections of the core body.