JP3017029U - Writing instrument cap - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a writing instrument cap in which an elastic body that seals a pen body of a writing instrument body is securely held by an elastic body holding portion and does not fall off. [Structure] In a writing tool cap, in which an elastic body 9 is press-fitted and held in an elastic body holding portion 4 at the tip of a cap body 1, and the pen body of the writing instrument body mounted on the cap is sealed by the elastic body 9, An inward projection 6 for preventing the elastic body from coming off is formed on the wall surface of the portion 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a writing instrument cap.

[0002]

[Prior art]

 In writing instruments that use ink, the pen of the writing instrument itself is often sealed with a cap for the purpose of preventing evaporation of ink from the pen when not in use. When the pen body is sealed with the inner cylinder inside the cap, this inner cylinder functions as a cylinder when the cap is attached and detached, and the volume of the closed space of the inner cylinder decreases and the pressure rises during the process of mounting the cap. . Therefore, this high-pressure air enters the ink cylinder and the pressure in the ink cylinder also becomes high, and the ink may be pushed out during writing to cause dripping. Further, in the process of removing the cap, the volume of the closed space of the inner cylinder is increased and the pressure is reduced, and the ink may be drawn out from the ink cylinder.

For this reason, in the case of a ballpoint pen or the like, an elastic body such as rubber is held in the elastic body holding portion at the tip of the cap, and the pen body is pressed against the elastic body when the writing instrument main body is mounted on the cap. In many cases, the tip of the pen body is covered and sealed by deforming into a concave shape. By thus sealing the pen body with the elastic body, not only the evaporation of the ink is prevented but also the ink is prevented from leaking into the cap when a shock is applied.

[0004]

[Problems to be solved by the device]

 By the way, in the structure that holds the elastic body, it is often the case that the elastic body holding portion is formed into a cylindrical shape and a spherical elastic body is press-fitted into the elastic body holding portion.In this case, the outer diameter of the elastic body in its natural state is The inner diameter of the elastic body is made slightly larger than the inner diameter of the cylindrical elastic holding portion to hold the elastic body in a contracted state.

At this time, if the outer diameter of the elastic body in the natural state is too large, the press-fitting resistance becomes large and it is difficult for the elastic body to be press-fitted into the elastic body holding portion, and the elastic body receives a large compression pressure after the press-fitting. The elastic body is unlikely to deform into a concave shape when pressure is applied to the seal, resulting in incomplete sealing. For this reason, it is preferable to design the outer diameter of the elastic body as small as possible.However, if the design size is made small, the elastic body cannot be held securely due to dimensional variations during manufacturing of the elastic body and the elastic body holding part of the cap. May be dropped.

Therefore, an object of the present invention is to provide a writing instrument cap in which an elastic body that seals a pen body of a writing instrument body is securely held by an elastic body holding portion and does not fall off.

[0007]

[Means for Solving the Problems]

 In order to achieve such an object, the present invention provides a cap for a writing instrument in which an elastic body is press-fitted into an elastic body holding portion at a tip of a cap body to seal a pen body of a writing instrument body attached to the cap with the elastic body. In, an inward projection for preventing the elastic body from coming off is formed on the wall surface of the elastic body holding portion.

[0008]

[Action]

 That is, since an inward protrusion for preventing the elastic body from coming off is formed on the wall surface of the elastic body holding portion of the cap body, it is easy to press-fit and the elastic body is easily deformed when the pen body is pressed. Even if the body design size is reduced, the elastic body is securely held and does not fall off.

[0009]

【Example】

 The present invention will be described in detail below based on the embodiments shown in the drawings. Eight vertical ribs 2 are formed on the inner surface of a cap main body 1 formed of a synthetic resin in a bottomed tubular shape, and an inner cylinder 3 into which the pen body of the writing instrument main body is inserted is connected to the rib 2. The inner bottom of the inner cylinder 3 is the elastic body holding portion 4.

The elastic body holding portion 4 is formed with four holding ribs 5 that are inclined toward the abutment side, and the holding ribs 5 are formed with small inward projections 6 for preventing the elastic body from coming off. The spherical elastic body 9 made of, for example, silicon rubber is held by the holding rib 5. That is, an elastic body 9 having an outer diameter in a natural state, which is slightly larger than the inscribed circle of the holding rib 5, is put into the elastic body holding portion 4, and is pushed over the inward projection 6 to be held. When the pen body is pressed against the elastic body 9 when the pen body is attached to the cap (not shown), the elastic body 9 deforms into a concave shape and covers the tip of the pen body to seal the pen body. You can

Here, in order to easily press the elastic body 9 into the elastic body holding portion 4 and to easily deform the elastic body 9 when the pen body is pressed, if the design size is reduced, the elastic body 9 and the elastic body 9 are reduced. The holding ribs 5 of the holding portion 4 may not be sufficiently held by the holding ribs 5 of the elastic body 9 due to dimensional variation during manufacturing, but an inward projection 6 for preventing the elastic body from coming off is formed. Therefore, the elastic body 9 can be securely held in the elastic body holding portion 4 without falling off.

[0012]

[Effect of device]

 As described above, according to the present invention, the elastic body is pressed into the elastic body holding portion at the tip of the cap body, and the pen body of the writing instrument body attached to the cap is sealed with the elastic body. Since the inward protrusion for preventing the elastic body from coming off is formed on the wall surface of the portion, the writing tool cap can be securely held by the elastic body holding portion and will not fall off.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap body 2 Vertical ribs 3 Inner cylinder 4 Elastic body holding part 5 Holding rib 6 Inward projection 9 Elastic body

Claims (1)

[Scope of utility model registration request] 1. A writing instrument cap in which an elastic body is press-fitted into an elastic body holding portion at a tip of a cap body to seal a pen body of a writing instrument body mounted on the cap with the elastic body, wherein a wall surface of the elastic body holding portion is provided. A writing instrument cap, wherein an inward projection for preventing the elastic body from coming off is formed on the.