JPH10100581A - Water base ink ballpoint pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always maintain a head of ink constant irrespective of an ink amount and to write with a predetermined thickness by disposing an internal pressure regulating tube for communicating a tail end opening with the atmosphere and formed of water repellent material disposed at its end opening near a tip in an ink tank at its tail end face formed in a closed space. SOLUTION: A tail end face 12 of an ink tank 1 is formed in a closed closing space, and a ballpoint pen tip 3 is mounted at an end small-diameter part 11. A tail end part of an internal pressure regulating tube 2 made of a water repellent material disposed in the tank 1 is held at the face 12 of the tank 1, and its tail end opening 2a is exposed from the face 12 of the tank 1 to communicate with the atmosphere. And, the vicinity of the end of the tube 2 is held by a rib 14 formed at the tank 1, and the opening 2a is disposed near the tip 3. Thus, head of ink L applied to a ball 4 in the tip 3 becomes constant irrespective of the quantity of the ink L so that flow rate of the ink L becomes constant. Thus, it can always write with the same handwriting thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ballpoint pen in which an ink tank is directly filled with an aqueous ink.

[0002]

2. Description of the Related Art Water-based inks have much lower viscosity than oil-based inks, so ballpoint pens using water-based inks have the advantage that they can be written with light writing pressure and have good writing quality. It is difficult to accurately control the amount of ink ejected, and there is a problem that the ink easily leaks to the outside. For this reason, conventionally, a water-based ballpoint pen has been widely put into practical use, in which water-based ink is stored in an ink-absorbing body called a batting formed by shaping thin fibers into a rod shape, and the ink in the ink-absorbing body is supplied to a ball at the tip of a chip through a relay core. .

[0003] However, the filling type water-based ballpoint pen has a problem that the writing distance is short because the filling amount of ink of the filling is small, and it is difficult to find the end point where the ink has been used up. For this reason, recently, a so-called raw ink type water-based ballpoint pen, which has a statically high viscosity, but is directly filled into an ink tank with a water-based ink whose viscosity is reduced due to the shearing force due to the rotation of the ball and which easily flows, is practically used. Has been

In such a raw ink type water-based ballpoint pen, a grease-like backflow preventing agent that fills an ink into an ink tank having a tail end opening open to the atmosphere and moves forward with the consumption of ink toward the tail end of the ink. To prevent the ink from flowing out of the tail end opening of the ink tank. However, if the ink head is exposed to the backflow preventive when the writing implement is turned upward, the ink will flow out of the tail end opening of the ink tank together with the backflow preventive, so that the ball held freely by the chip will rotate. The tip of the tip is made into a valve structure by contacting the inward tip edge of the tip with a spring to prevent the ink head from flowing back when the writing tool is turned upward with the valve closed when not writing. I try not to get on the medicine.

[0005]

In such a raw ink type water-based ball-point pen, when writing, the ball retreats due to the writing pressure, the valve mechanism opens, and the ink flows out with the rotation of the ball to write. However, the amount of ink flowing out depends on the ink head. In other words, when the ink in the ink tank is large, the ink head is large, so the amount of outflow is large and the handwriting becomes thick, and as the ink is consumed, the outflow decreases and the thickness of the handwriting changes. There is.

Accordingly, an object of the present invention is to provide an aqueous ballpoint pen in which the head of the ink is always constant irrespective of the amount of ink in the ink tank and writing can be performed with a constant handwriting thickness. .

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method for holding a ball in a freely rotatable manner with a part of the ball protruding from an opening at the tip end of a chip, and the ball is supported by a spring. The tip of the ink tank filled with the water-based ink is contacted with the tip of the ink tank filled with the water-based ink, and the tip end of the water-based ball-point pen is attached to the tip of the ink tank. An internal pressure adjusting tube, which is made of a water-repellent material, has a tail end opening communicating with the atmosphere, and a tip end opening located near the chip, is disposed in the ink tank.

[0008]

Embodiments of the present invention will be specifically described below with reference to the drawings. In FIG. 1, the ink tank 1 is different from a conventional water-based ball-point pen using a grease-like backflow preventing agent, and its tail end surface 12 is a closed space. The ballpoint pen tip 3 is attached to the small diameter portion 11 at the tip of the ink tank 1. In the illustrated example, the ink tank 1 and the small-diameter portion 11 are integrally formed. However, the small-diameter portion 11 may be formed as a separate part and attached to the ink tank 1.

The chip 3 is formed in a shell shape from stainless steel, and a ball 4 is rotatably held at the tip of the tip 3 with the tip of the ball protruding from the tip 3. As shown in FIG. 2, a spring 5 composed of a coil spring is disposed in the chip 3, and the spring 5 rebounds the ball 4 to inwardly move the tip 3 of the chip 3.
The ball 4 and the tip end edge 31 of the chip 3 constitute a valve mechanism. Here, the spring load of the spring 5 is 5 to 300 g. The ball 4 is made of a carbide ball having a diameter of, for example, 0.5 mmφ, and is disposed in the ball house 32 of the chip 3. The ball house 32 communicates with the ink passage hole 36 through the center hole 33 and the vertical groove 34, but during writing, the ball 4 retreats and contacts the seat 35 of the ball house 32 and rotates.

In the ink tank 1, an internal pressure adjusting tube 2 made of a repellent material is disposed. That is, the tail end portion of the internal pressure adjusting tube 2 is held by the tail end surface 12 of the ink tank 1, and the vicinity of the tip end is held by the rib 14 formed on the partition 13 of the ink tank 1. The tail end opening 2 a of the internal pressure adjusting tube 2 is connected to the tail end surface 1 of the ink tank 1.
2 and communicates with the atmosphere, the tip opening 2b of the internal pressure adjusting pipe 2 is located near the chip 3, and the distance H between the tip opening 2b and the ball 4 is a constant value. At the tail end of the ink tank 1, a tail plug (not shown) having a vent hole is attached as necessary.

The ink tank 1 is filled with the water-based ink L. When the ballpoint pen is turned downward, the space S in the ink tank 1 is a closed space that does not communicate with the atmosphere. For this reason, atmospheric pressure is applied to the aqueous ink L at a distance H from the ball 4. Therefore, regardless of the amount of the ink L, the ball 4 in the chip 3
The head of the ink L is constant at H. Thus, the ink tank 1 has a structure known as a “Marriott bottle”.

When writing with the ballpoint pen facing downward, the space S in the ink tank 1 is depressurized as the ink L is consumed, but when the space S is depressurized, the air in the internal pressure adjusting pipe 2 is released from the tip opening 2b. And enters in a small bubble state, the bubble rises in the ink L and reaches the space S,
The pressure in the space S balances with the atmospheric pressure. At this time, irrespective of the amount of the ink L, the head of the ink L applied to the ball 4 in the chip 3 has a constant value of H, so that the amount of ink flowing out by writing is constant, and the handwriting thickness is always constant. Can be written.

When the ballpoint pen is turned upward from below, the valve mechanism at the tip of the tip 3 located on the upper side is closed, so that the ink L existing above the tip opening 2b of the internal pressure adjusting tube 2 has a large size. No air pressure is applied, the ink L does not flow out of the internal pressure adjusting pipe 2, and the ink L is replaced with the air in the space S in the ink tank 1 and is placed on the tail end side of the ink tank 1, that is, below the ballpoint pen. Moving. Also, when the ball-point pen is left sideways, the space S in the ink tank 1 is somewhat depressurized and the internal pressure adjusting pipe 2
Is made of a repellent material, and the opening 2 at the end of the internal pressure adjusting pipe 2
The ink L does not flow out of the internal pressure adjusting tube 2 due to the surface tension acting on b.

However, if the temperature of the ink tank 1 becomes significantly higher than the outside air temperature for some reason, the pressure in the space S becomes higher than the atmospheric pressure, and the ink L may flow backward and enter the internal pressure adjusting pipe 2. . Accordingly, although not shown, the internal volume of the internal pressure adjusting tube 2 is made smaller than the expected reverse flow rate of the ink L by making the internal pressure adjusting tube 2 helical or providing an enlarged portion in the middle of the internal pressure adjusting tube 2. It is better to make it larger.

[0015]

As described above, the water-based ball-point pen of the present invention closes the tail end surface of the ink tank to form a closed space, and is made of a water-repellent material. Since the internal pressure adjusting tube located in the vicinity of the chip is disposed in the ink tank, the head of the ink applied to the ball in the chip has a constant value regardless of the amount of ink. For this reason, the amount of outflow of ink by writing becomes constant, and writing can always be performed with a constant handwriting thickness.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of an internal structure of a chip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink tank 11 Small diameter part of ink tank 12 Tail end face of ink tank 2 Internal pressure adjusting tube 2a Tail opening of internal pressure adjusting tube 2b Tip opening of internal pressure adjusting tube 3 Tip 31 Inward tip edge of tip 4 Ball 5 Spring

Claims (1)

[Claims] 1. A ball is held rotatably with a part of the ball protruding from a tip opening of a chip, and the ball is repelled by a spring to contact an inward tip edge of the chip, In a water-based ball-point pen attached to the tip of an ink tank filled with water-based ink, the tip of the ink tank is closed to form a closed space by closing the tail end surface of the ink tank and made of a repellent material, and the tail end opening communicates with the atmosphere. An aqueous ballpoint pen, wherein an internal pressure adjusting tube having a tip opening located near the chip is disposed in the ink tank.