JPH0237584Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the airtight structure of a cap press writing instrument in which the pen end protrudes and retracts from the barrel opening. Conventionally, various structures for maintaining airtightness at the tip of a writing body have been devised and put into practical use. However, many of them have advantages and disadvantages,
Products that place emphasis on simplicity have drawbacks in terms of durability and reliability, while products that pursue reliability and durability come with complexity.
It has been difficult to find a rational product that is durable and reliable.

The present invention aims to eliminate the drawbacks of these prior art techniques and provide an airtight structure at the tip of a writing instrument that is simple, reliable, and durable.

Hereinafter, embodiments of the present invention will be described based on the drawings.

An inner tube 2 is accommodated in the barrel 1, and the inner tube 2 has a writing body 3 having a brush end portion 3a having a ball portion at the tip, which is movable back and forth in the axial direction by an appropriate means. is built-in. The shaft tube 1 and the inner tube 2 are made relatively movable by appropriate means (not shown). In other words,
When the writing body 3 moves toward the cylinder opening 1a due to the action of a writing body retraction mechanism (not shown), the barrel 1 and the inner cylinder 2 move forward as the writing body 3 moves forward. , the barrel 1 moves forward or the inner barrel 2 moves backward as the writing body 3 moves, and is arranged between the opening 1a of the barrel 1 and the opening 2a of the inner barrel 2. A valve body 4, which will be described later, is spaced apart from the shaft cylinder opening 1a and the inner cylinder opening 2a.

The valve body 4 is disposed between the barrel opening 1a and the inner barrel opening 2a at a position facing the barrel opening 1a. 2, the openings 1a, 2a are held by a telescopic and elastic holding member 5 fixed to the outer peripheral surface of the tip of the inner cylinder 2.
The barrel opening 1a is closed while being held between the two. At this time, it goes without saying that the holding member 5 is reduced in size. Reference numeral 5a denotes a gap provided in the holding member 5, in which the shaft cylinder 1 and the inner cylinder 2 are separated from each other, and the holding member 5
When extended, the brush end 3a of the cursive 3 is realized.
When exposed from the barrel opening 1a, the valve body 4 is removed from the gap 5a and exposed.

Note that the size of the valve body 4 needs to be larger than the diameters of the axial cylinder opening 1a and the inner cylinder opening 2a, but the shape may be determined as appropriate, for example, the brush end of the valve body 4. If the side surface facing the part 3a is made into a circular or spindle-shaped part 4a, the brush end part 3a
It is useful to eliminate this when it is exposed. As mentioned earlier, reference numeral 3 is a cursive font, and the operation of exposing the cursive font from the barrel opening 1a is carried out by the action of a cursive body retraction mechanism (not shown). When moving in the direction 2a, either the inner cylinder 2 or the shaft cylinder 1 moves backward or forwards to separate the valve body 4 from the cylinder opening 1a and the inner cylinder opening 2a. That is, both 1a, 2
By a, the holding member 5 is contracted, and as the holding member 5 expands, both 1a and 2a open the valve body 4 which is blocking the barrel opening 1a in the clamped state.

The cursive 3 moving forward will eventually reach its brush end 3.
The valve body 4 is removed from the gap 5a of the holding member 5 extended at point a.
is removed, and is further advanced to be exposed from the barrel opening 1a (see FIGS. 2 and 3). When the brush end 3a sinks into the inner cylinder 2, either the inner cylinder 2 or the barrel 1 moves in the opposite direction to the above-mentioned operating direction, and the valve body 4 is brought into contact with the barrel opening 1a. It will be held between the cylinder openings 2a. At this time, the holding member 5 of the valve body is compressed and accommodated in the inner surface of the shaft cylinder 1 and the outer surface of the inner cylinder 2 (see FIG. 1).

As described above, in this case, the valve body, which is held by an elastic holding member that is expandable and retractable between the shaft cylinder opening and the inner cylinder opening and forms a gap when extended, is placed in a position facing the shaft cylinder opening. As the writing body moves toward the opening of the barrel, the barrel and inner barrel move relative to each other in the axial direction in the front-rear direction. When the writing body is immersed in the inner cylinder, the valve body can be held between the shaft cylinder opening and the inner cylinder opening while contracting the holding member, so that the outside air is not blocked at the shaft cylinder opening. Realize it more reliably and easily. In addition, in the process of reaching the writing state, the valve body is released from the clamping state, so the holding member expands, and as a result, a gap is formed in the holding member. The valve body is removed from the valve body and exposed from the shaft cylinder opening. Therefore, damage to the tip ball portion of the brush end and the valve body is relatively minor, and deterioration over time is significantly delayed. In addition, since the valve body is held by a telescoping holding member fixed to the outer circumferential surface of the tip of the inner cylinder, it is difficult to hold it between the openings of the shaft cylinder and the inner cylinder, and to release it. Since it can be done smoothly without the action of force, it is possible to obtain a structure that maintains the tip of the writing instrument airtight and has excellent durability.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams of the relationship between the tip airtight retaining structure in which the present invention is implemented and the protrusion/retraction operation of the brush end, and Figure 1 relates to the airtight retaining structure when the brush end is retracted. Side sectional explanatory diagram, Fig. 2,
Fig. 3 is a side sectional explanatory view of the exposure operation of the brush end and the airtight maintenance structure, Fig. 4 is a side sectional explanatory view of the relational structure between the valve body and the tip of the inner cylinder, and Fig. 5 is the 4th sectional view.
It is a top view of a figure. 1a...Shaft cylinder opening, 2a...Inner cylinder opening, 3
a... Brush end, 4... Valve body, 5... Holding member, 5
a...Void portion.

Claims (1)

[Scope of utility model registration request] In a cap press writing instrument in which the brush end protrudes and retracts through an opening provided in the barrel, an inner barrel 2 containing a writing body 3 is housed in the barrel 1, and the tip of the inner barrel 2 faces the barrel opening 1a. An opening 2a is provided at a position where the inner cylinder 2
A valve body 4 held by an elastic holding member 5 which is fixed to the outer peripheral surface of the tip and which is elastic and which forms a gap 5a when extended is disposed at a position facing the shaft cylinder opening 1a, and the shaft cylinder 1 and inner tube 2 in cursive 3
The valve body 4 is arranged so as to move relative to the front and rear directions in the axial direction as the cylinder moves toward the cylinder opening 1a, and when the cylinder 1 and the inner cylinder 2 are separated, the valve body 4 moves toward the cylinder opening 1a. An airtight maintenance structure for a tip part of a cap press writing instrument, characterized in that a holding member 5 is extended at the same time as being separated from a portion 1a and an inner cylinder opening 2a.