JP3168101U - Ballpoint pen - Google Patents

Abstract

Provided is a ballpoint pen that supports simple upward writing with a simple structure. A shaft portion 2 is provided with a cylinder portion 3a and a piston 7, and a cylinder chamber is formed by the cylinder portion and the piston. On the other hand, the refill holder 4 that holds the hall pen refill 6 is fixed to the shaft tube. The refill holder is formed with a communication path that connects the rear end opening of the ballpoint pen refill and the cylinder chamber. The piston is provided with a guide portion 7a for guiding the weight 8 so as to be movable in the axial direction of the cylinder. On the guide portion, there are provided restricting portions 7b and 7c for defining the movement limit of the weight before and after. [Selection] Figure 1

Description

  The present invention relates to a so-called pressure mechanism of a ballpoint pen.

  Conventionally, in order to prevent the phenomenon of ballpoint pen not writing when writing upward with a ballpoint pen (writing with the pen tip facing up), a pressure type that forcibly pushes the ballpoint pen ink to the pen tip side by gas pressure Writing instruments have been devised.

  The ballpoint pen disclosed in Patent Document 1 is a so-called knock-type ballpoint pen. In this ballpoint pen, the pen tip can be moved in and out by a knocking operation, and when the pen tip protrudes and becomes ready for writing, pressure is applied, and when the pen tip is immersed and stored, the applied pressure is released. A mechanism is disclosed.

  The ballpoint pen disclosed in Patent Document 2 discloses a gas pressure type ballpoint pen in which an inert gas is sealed in a ballpoint pen refill.

JP-A-2005-138356 JP 2003-215881

  When the ink in the ballpoint pen refill is constantly pressurized, it is necessary to form a ball holding mechanism for the pen tip so that it can sufficiently withstand the applied pressure, and the pressurized gas in the ink tank It is necessary to form the ink tank so as not to reduce pressure. However, if the pressure is temporarily applied at the time of writing, a normal ballpoint pen refill used in a non-pressurized state can be used. In this case, the pressurizing mechanism disclosed in Patent Document 1 that is pressurized only at the time of writing is effective. However, this pressurizing mechanism cannot be applied to a cap-type ballpoint pen in which a ballpoint pen refill is fixed to the shaft cylinder. On the other hand, there is a gas pressurization method disclosed in Patent Document 2 in order to enable such a cap-type ballpoint pen to be used for upward writing. However, in this case, as described above, the ball holding mechanism of the pen tip of the ballpoint pen is configured so that it can withstand the applied pressure constantly, and means for preventing the pressurized sealed gas from permeating from the ink tank (Materials, coatings, etc.) must be configured. Therefore, it is not possible to use a normal ballpoint pen refill used in a non-pressurized state, resulting in a complicated and expensive configuration.

  In the present invention, a cylinder portion and a piston are provided in a shaft cylinder, and a cylinder chamber is formed by the cylinder portion and the piston. On the other hand, a refill holder for holding a hole pen refill is fixed to the shaft tube. The refill holder is formed with a communication path that connects the rear end opening of the ballpoint pen refill and the cylinder chamber. The piston is provided with a guide portion that guides the weight so as to be movable in the axial direction of the cylinder. On the guide part, a restricting part for defining a movement limit before and after the weight is provided.

  According to the present invention, when the pen tip is directed upward, the weight moves to the rear end side of the shaft cylinder, and the weight comes into contact with the rear restricting portion. Since the restricting portion and the piston are fixed, the piston moves rearward due to the impact of the weight colliding with the restricting portion, and compresses the cylinder chamber. This compressed air pressurizes the ink in the ink tank from the rear end opening of the ballpoint pen refill through the communication path. On the other hand, when the pen tip is directed downward, the weight comes into contact with the front restricting portion, and the piston moves forward by the impact at that time, and the pressurization of the cylinder chamber is released.

  In this way, since the ink in the ballpoint pen refill is pressurized only when writing upwards that requires pressurization (that is, with the pen tip facing up), the ballpoint pen refill can withstand the pressure constantly. There is no need to configure, and a normal ballpoint pen refill can be used. With the configuration of the present invention, it is possible to provide a writing instrument corresponding to upward writing with a simple configuration for a cap-type ballpoint pen in which a ballpoint pen refill is fixed to a shaft cylinder.

1 is a half sectional view of a main body of a cap-type ballpoint pen according to an embodiment of the present invention. (A) is a longitudinal cross-sectional view which shows the case where a weight is located in the front end, (b) is a longitudinal cross-sectional view which shows the case where a weight is located in the back end. It is an expanded longitudinal cross-sectional view which shows the operation state of the principal part. (A) shows the case where the weight is located at the front end, and (b) shows the case where the weight is located at the rear end.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the forward direction refers to the direction on the pen tip (6c) side.

1 to 3 show a ballpoint pen body 1 to which the present invention is applied.
In FIG. 1, a main body 1 has a shaft cylinder 2 formed in a cylindrical long shape. A tail plug member 3 is screwed and fixed to the rear end of the shaft tube 2. On the other hand, a front port 5 is provided in front of the shaft tube 2 with an annular rib 4a of a refill holder 4 described later interposed therebetween. The refill holder 4 is formed in a cylindrical shape, and is provided with a cylindrical portion 4 b that holds the ink tank 6 a of the ballpoint pen refill 6. A large-diameter portion 4c is formed in a cylindrical shape at the front end of the cylindrical portion 4b. And the front-end | tip holding | maintenance part 4d is formed in the cylindrical shape through the annular rib 4a ahead from the large diameter part 4c. Male screw portions 4c1 and 4d1 are formed on the outer periphery of the large diameter portion 4c and the outer periphery of the front end holding portion 4d. That is, a female nude portion 2 a is formed on the inner peripheral surface of the front end portion of the above-described shaft cylinder 2, and is screwed and connected to the male screw portion 4 c 1 of the refill holder 4. Similarly, a female screw portion 5a is also formed on the inner surface of the rear end opening of the front port 5, and is thereby screwed and connected to the male screw portion 4d1. The rear end opening end face of the front opening 5 and the front end end face of the shaft tube 2 are screwed and fixed until they contact the annular rib 4a. Further, the pen tip 6 c of the ballpoint pen refill 6 protrudes from the tip opening 5 b of the tip 5.

  The piston guide 4e formed to extend rearward from the cylindrical portion 4b of the refill holder 4 is formed in a cylindrical shape. On the other hand, a cylinder portion 3 a is formed in front of the tail plug member 3. A piston 7 is formed between the cylinder portion 3a and the piston guide 4e. The piston 7 is guided so as to be movable in the axial direction along the piston guide 4e. The piston 7 is formed with a guide portion 7a extending in a cylindrical shape forward along the cylindrical portion 4b. A weight 8 is formed on the outer periphery of the guide portion 7a. The weight 8 is guided so as to be movable in the axial direction along the guide portion 7a. Further, the guide portion 7 a is formed with restricting portions 7 b and 7 c that are in contact with the weight 8 and define the movement limit of the front and rear of the weight 8 in the vicinity of the front end and the rear position.

  Here, the structure of the cylinder part 3a and the piston 7 will be described in detail. As shown in FIGS. 3 (a) and 3 (b), with respect to the cylinder portion 3a, the diameter of the area located at the rear (pressure area 3a1) is the area (open area) that is connected to the pressure area 3a1 and extends forward. The diameter is smaller than 3a2). An O-ring 7 d is provided on the outer peripheral surface near the rear end of the piston 7. The O-ring 7d and the inner peripheral surface of the cylinder portion 3a are airtight when the O-ring 7d is positioned in the pressurizing region 3a1 (see FIG. 3B), and is airtight in the open region 3a2. Absent.

  Furthermore, a cylinder chamber S is formed by the piston 7 and the cylinder portion 3a. A hole (connection path 7e) is formed in the center of the rear end surface of the piston 7. An O-ring 4 f is also provided on the outer periphery of the piston guide 4 e of the refill holder 4. A region formed by the O-ring 4f and the inner peripheral surface of the piston 7 and the inner surface of the rear end portion of the piston 7 is airtight. The rear end portion of the refill holder 4 is provided with a communication path 4g that is hollow and communicates with the connection path 7e. The front end of the communication path 4g has a stepped portion in the direction of expanding the diameter, and the rear end of the ballpoint pen refill 6 (ink tank 6a) is in contact with the O-ring 6b. The space from the communication path 4g to the ink tank 6a is kept airtight by the O-ring 6b.

In other words, the cylinder chamber S communicates with the rear end opening of the ink tank 6a through the connection path 7e and the communication path 4g.
In order to use the main body 1 of the ballpoint pen according to the present embodiment as a cap-type ballpoint pen, a cap having a known configuration may be provided in the front end 5 (or the shaft tube 2).

  Next, the operation of this embodiment will be described. In the case of writing with a normal pen tip 6c facing downward, the weight 8 is in contact with the restriction portion 7b on the front side. Therefore, the piston 7 moves to the front limit position (that is, the position where the front end of the guide portion 7a abuts on the large diameter portion 4c and / or the position where the piston 7 and the refill holder 4 abut on the rear portion) due to the gravity of the weight 8. (FIG. 2 (a) and FIG. 3 (a)). Here, when writing with the pen tip 6c facing upward, the weight 8 moves until it comes into contact with the rear restricting portion 7c. The piston 7 moves rearward due to the impact when the weight 8 and the restricting portion 7c come into contact with each other and the gravity of the weight 8. At this time, the rear end surface of the piston 7 comes into contact with the surface of the cylinder portion 3a facing the rear end surface of the piston 7, and the cylinder chamber S is compressed. Since the piston 7 is located in the pressurizing region 3a1, the connection path 7e and the communication path 4g are kept airtight. Therefore, as the cylinder chamber S is compressed, the chambers such as the connection path 7e and the communication path 4g are pressurized, and as a result, the rear end opening of the ink tank 6a communicating with these is pressurized. Therefore, the ink in the ink tank 6a is pressurized forward, so that upward writing can be performed.

  If the pen tip 6c is turned downward again, the weight 8 moves forward. Then, the weight 8 comes into contact with the front regulation portion 7b. The piston 7 moves forward by the impact when the weight 8 and the restricting portion 7b come into contact with each other and the gravity of the weight 8. At this time, the vicinity of the rear end of the piston 7 (O-ring 7d) is located in the open region 3a2, so that the cylinder chamber S that is formed again does not become negative pressure, and the vicinity of the rear end of the piston 7 (O-ring 7d). Outside air flows from the outer periphery of the.

  As mentioned above, although the Example of this invention was described in detail, this invention is not limited to this, It can change suitably in the range which does not change the summary of this invention.

2 Shaft 3 Tail plug member 3a Cylinder portion 4 Refill holder 4b Cylindrical portion 4g Communication passage 6 Ballpoint pen refill 6c Pen tip 7 Piston 7a Guide portion 7b Restriction portion 7c Restriction portion 7e Connection path 8 Weight S Cylinder chamber

Claims (2)

A cylinder part provided on the shaft tube;
A piston forming the cylinder part and the cylinder chamber;
A refill holder fixed to the shaft cylinder and holding a ballpoint pen refill, and having a communication passage communicating the rear end opening of the ballpoint pen refill and the cylinder chamber;
A weight guided movably in the axial direction of the cylinder by a guide portion provided continuously with the piston;
A restricting portion which is provided in the guide portion and defines a movement limit of the weight before and after;
A ballpoint pen comprising: The ballpoint pen according to claim 1, wherein the piston includes a connection path that connects the communication path and the cylinder chamber.

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