JPS6139591Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a barrel neck structure of a marking pen.

Conventionally, a barrel made of aluminum is used as an ink storage part, a plastic packing member to prevent ink leakage is fitted on the inner surface of the upper end opening of the barrel, and a neck member that holds a pen body is attached to the outer surface. marking pens are widely used. However, this type of marking pen often suffers from contamination due to ink seeping from the neck of the barrel, causing trouble. This is due to the fine capillary gap formed between the inner surface of the upper end opening of the barrel and the fitting part of the packing member, specifically the contact interface between the two, and the ink inside the barrel is absorbed through the gap by capillary action. It was found that the result was transmitted to the neck. Conventionally, in a structure in which a soft flexible plastic packing member made of polyolefin resin or the like is tightly inserted into the inner surface of an aluminum shaft cylinder, when the packing member is inserted, the upper end opening surface of the shaft cylinder and the inner wall surface of the shaft cylinder are This is caused by the generation of minute scratches on the surface of the packing member.

The present invention provides a marking pen barrel neck structure that suppresses the occurrence of this type of scratches, eliminates troubles caused by ink oozing, and is effective in terms of insertion processing efficiency.

The present invention will be explained in detail below with reference to the drawings.
FIG. 1 illustrates a longitudinal cross-sectional view of a main part of an embodiment of the present invention. FIG. 2 is an external view of the short cylindrical body of FIG. 1, and FIGS. 3 and 4 are other examples of the short cylindrical body. As shown in the illustrated example, the present invention uses the body of the shaft cylinder 1 made of aluminum material as an ink storage part, and the vicinity of the upper end opening of the shaft cylinder has a shape that widens in a tapered shape toward the opening end,
This is a barrel neck structure of a marking pen in which a specific packing member for preventing ink leakage is fitted on the inner surface and a neck member 12 holding a pen body 11 is attached to the outer surface. Specifically, the packing member inserted through the expanded portion 2 is a short plastic cylinder 3 having a flange-like edge 4.
The short cylindrical body has the lower surface of the flange-like edge locked with the open end surface of the shaft tube, and the circumferential surface of the large diameter portion 5 near the end is closely fitted to the inner wall of the shaft tube 1. It is characterized by The short cylindrical body 3 is effectively made of plastic material, and the large diameter portion 5 is not limited to a raised large diameter portion with a tapered step formed near the end as shown in FIG. As shown in FIG. 4, it is also effective to use a short, tapered cylindrical body with a large diameter near the end.

Fig. 1 shows an example of the barrel neck of a liquid writing instrument, and the short plastic barrel 3, which is a packing member, is an example in which an ink discharge mechanism for discharging ink toward the pen tip is built inside the short plastic barrel 3. be. A valve body 7 is resiliently pressed against the valve seat 6 of the valve seat member from behind by a spring member 8, and one end of a valve stem 9 extending from the valve body is connected to the rear end of the pen body. The other end is made to protrude from the bottom surface of the short cylindrical body, and the valve body 7 is opened by pressing the front end of the pen body 11, and the through hole 1 is opened.
The ink introduced from 0 is extracted.

The present invention is particularly effective for this type of liquid marker.

The effects of the above configuration of the present invention will be described below. The shaft cylinder of the present invention has a shape in which the vicinity of the upper end opening of the shaft cylinder made of aluminum is tapered toward the opening end, and the vicinity of the end of the short cylinder body is larger than the front end side. diameter, and the circumferential surface of the large diameter portion is closely fitted to the inner wall of the shaft cylinder.Furthermore, the inner wall of the shaft cylinder at the fitting portion has a curved taper, so that effective pressure can be applied. It can be fitted smoothly, and there is no possibility of generating minute scratches that become capillary gaps on the circumferential surface of the short cylindrical body. Note that the tapered expanded shape of the aluminum material near the upper end opening of the shaft cylinder can be easily achieved by processing means such as press-inserting a processing tool made of a metal material or the like corresponding to the shape into the location. .

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a main part of an embodiment of the present invention, FIG. 2 is an external view of the short cylindrical body of FIG. 1, and FIGS. 3 and 4 are external views of other examples of the short cylindrical body. 1... Shaft tube, 2... Tapered expanded portion, 2-1
... Taper part base, 3 ... Short cylinder body, 4 ... Flange-shaped edge, 5 ... Large diameter part, 6 ... Valve seat, 7 ... Valve body, 8 ... Spring material, 9 ... Valve Bar, 10...
Through hole, 11...pen body, 12... neck member.

Claims (1)

[Scope of utility model registration request] A barrel made of aluminum is used as an ink storage part, a packing member to prevent ink leakage is fitted on the inner surface of the upper end opening of the barrel, and a neck member for holding a pen body is attached to the outer surface. In this marking pen, which supplies ink to the writing tip by pressing the front end of the pen body and activating the valve body, the barrel 1 has a tapered expanded portion 2 with the vicinity of the upper end opening facing toward the opening end. The packing member is a soft flexible plastic short cylinder 3 having a flange-like edge 4, and has a valve mechanism therein. A marking pen in which the lower surface of 4 is locked to the open end surface of the barrel tube 1, and the outer circumferential surface of the large diameter portion 5 near the end is closely fitted to the inner circumferential wall of the tapered portion base 2-1 of the barrel tube 1. axial cylinder neck structure.