JPS625352Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a writing instrument equipped with a so-called refill that replaces the cartridge with a new cartridge when the ink is used up.

Conventionally, in this type of writing instrument, an air hole is provided in the refill to activate the outflow of ink inside the refill, but on the other hand, in order to prevent ink from evaporating from the air hole as much as possible, the air hole and the space at the rear end of the barrel are provided. In many cases, there is an airtight shield between the and,
A typical conventional shielding structure is, for example, the one described in Japanese Utility Model Publication No. 56-39667, which consists of a large diameter part and a small diameter part, and ink is passed from an ink storage body housed in the large diameter part through an inductive core. In a ballpoint pen, in which an ink cartridge is removably housed in a shaft cylinder, the ink cartridge is supplied to a ball holding part and is blocked from airflow except through a ventilation hole bored in a small diameter part and the ball holding part. , a structure in which a stepped portion facing the outer end of the large diameter portion of the ink cartridge is provided on the inside of the barrel, and a ventilation blocking member is interposed between the opposing step and the outer end of the large diameter portion. However, in this type, a stepped portion is provided on the inside of the barrel cylinder, facing the outer end of the large diameter portion of the ink cartridge, and this opposing step is connected to the outer end of the large diameter portion of the ink cartridge. It is necessary to interpose a ventilation blocking member between the parts, and in particular, the ventilation blocking part installed in the same part is required to be highly accurate, and its installation at the above location also needs to be done precisely. Products of the same type had defects such as an extremely high defective rate.

The purpose of the present invention is to provide a writing instrument that eliminates these drawbacks.

The present invention provides an outer stepped portion with a curved peripheral edge shoulder slightly behind the air hole in the re-feel, and an air-tight seal between the outer stepped portion of the re-feel and the inner hole of the barrel or base that accommodates the re-feel. The re-feel is inserted from the rear end of the barrel, and the curved convex portion of the outer step is airtightly inserted into the curved concave portion of the inner surface step of the barrel. By bringing them into contact with each other, the space between the air hole and the rear end space of the shaft cylinder is shielded.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The figure is a partially omitted vertical cross-sectional view of the writing instrument, and the barrel is made of a synthetic resin (or metal may be used) front barrel 1 with an integrated base, and the rear barrel is made of synthetic resin (or metal may also be used). 2 are screwed together, and the leading shaft 1
A curved inner step 3 is formed in the inner hole of the mouthpiece slightly rearward from the tip, followed by a large diameter part 5 that accommodates the batting 4 and a small diameter part 7 in front of which the core 6 is inserted. The curved surface of the inner surface step 3 of the tip shaft 1 is attached to the tip corner of the large diameter portion 5 of the re-feel 9 made of synthetic resin (of course, metal may also be used) and has an air hole 8 in the small diameter portion 7. A convex outer step 10 is formed with a curved surface having the same curvature as the reel 9, and the re-reel 9 is inserted from the rear end of the barrel and is slightly pushed forward by the tail plug 11, so that the outer step 10 is pushed forward. axis 1
It is brought into airtight contact with the inner surface stepped portion 3 of the.
In addition, numeral 12 in the figure is a cap that is airtightly attached to the tip shaft 1.

As mentioned above, the present invention provides an outer surface step portion with a curved peripheral edge shoulder slightly behind the air hole of the re-feel, and an inner hole of the shaft cylinder or base that accommodates the re-feel. Since the curved inner surface step part is provided in airtight contact with the outer surface step part, the step part facing the outer terminal end of the large diameter part of the ink cartridge is provided on the inside of the shaft cylinder like the above-mentioned known one. Not only is it possible to eliminate the above-mentioned defects caused by this structure without requiring a configuration in which a ventilation blocking member is interposed between the facing step portion and the outer end portion of the large diameter portion, but also the present invention eliminates the need for a refill. Since the shielding contact part with the shaft cylinder has a curved shape, the contact area increases and the airtightness is improved. There are advantages such as ease of loading as there is no friction caused by contact with the protrusions.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view showing an embodiment of the present invention. 1... Front shaft, 2... Rear shaft, 3... Inner step, 4
...Badding, 5...Large diameter part of the refill, 6...Core body, 7...Small diameter part of the refill, 8...Air hole,
9... Refill, 10... Outer step of refill, 11... Tail plug, 12... Cap.

Claims (1)

[Scope of utility model registration request] A step on the outer surface of the refiel is provided with a curved peripheral shoulder at a slightly rearward portion of the air hole in the refiel, and the inner hole of the shaft tube or base that accommodates the refiel is brought into airtight contact with the step on the outer surface of the refiel. A writing instrument with a curved inner step.