JPS6144861Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a gas pressurized ballpoint pen, and particularly to a gas pressurized ballpoint pen with an improved tail plug.

The purpose of this is to create a tail plug tip in a gas pressurized ballpoint pen, which is made of a rubber-like elastic body with a diameter slightly larger than the inner diameter of the ink cylinder and a fitting hole formed on the rear end surface, and the tail plug tip. and a tail plug body which has a protrusion that fits into the fitting hole of the ink cylinder and is fixed within the rear end of the ink cylinder, and the fitting protrusion of the tail plug body has a circumferential groove at the base and faces toward the tip. A truncated conical surface is formed that gradually narrows as the shape of the fitting hole is formed. A locking protrusion protruding from the edge of the fitting hole is locked into the circumferential groove to integrate the tail plug tip and the tail plug body to provide a tail plug, and the tail plug is heated by pressurized gas. The tail plug body is fixed to the ink cylinder by press-fitting it into the ink cylinder indoors, and the tail plug tip is bulged in the radial direction by pressurized gas pressure inside the ink cylinder, making assembly easy and rubber To provide a gas pressurized ballpoint pen that is resistant to deterioration over time of a shaped elastic body, maintains the effect of sealing and holding a pressurized gas body, and also enables the sealing of even higher pressure gas bodies.

An embodiment of this invention will be described below based on the drawings.

In the figure, reference numeral 1 denotes an ink cylinder made of metal or synthetic resin with low air permeability that is not affected by ink 3, a tip 2 is fixed to the front end, and the inside is filled with ink 3. Reference numeral 4 in the figure denotes a float disposed on the rear end surface of the ink 3.

A tail plug 5 is disposed at the rear end opening of the ink cylinder 1. The tail plug 5 consists of a tail plug tip 6 made of a rubber-like elastic material and a tail plug main body 7 into which the tail plug tip 6 is fitted and fixed.

The tail plug tip body 6 is formed into a cylindrical shape with an outer diameter slightly larger than the inner diameter of the ink cylinder 1, and a chamfered portion 6A is formed on the periphery of the tip surface to facilitate insertion into the ink cylinder 1. A fitting hole 9 into which the fitting protrusion 8 of the tail plug body 7 is fitted is provided along the axis on the end face. The tail plug tip body 6 itself has an elastic force that expands in the radial direction by applying pressure from the front and rear directions.

The tail plug main body 7 has a fitting protrusion 8 at the center of the tip surface, and is made of synthetic resin or metal in a cylindrical shape as a whole, and its outer diameter is such that the tail plug main body 7 is press-fitted into the ink cylinder 1. The tail plug body 7 is formed to have a diameter slightly larger than the inner diameter of the ink cylinder 1 to such an extent that the tail plug main body 7 is not pushed out by the pressure of the pressurized gas inside the ink cylinder 1 when the tail plug body 7 is pressed out.

The fitting protrusion 8 is formed into a substantially cylindrical shape with a circumferential groove 8A at its base, and its distal end is formed into a truncated conical surface 8B that gradually narrows toward the distal end. Further, the fitting hole 9 is formed to have an inner surface that matches the fitting protrusion 8, and the hole edge has a circumferential groove 8A.
A locking protrusion 9A is provided in a protruding manner so as to fit inside and lock. Therefore, by fitting these fitting protrusions 8 and fitting holes 9 together, the tail plug tip body 6 is integrated with the tail plug main body 7.

To assemble, first, the tail plug tip body 6 is fitted into the tail plug main body 7 through its fitting hole 9 and fitting protrusion 8 to be integrated in advance, and then the rear end opening of the ink cylinder 1 is inserted into the pressurized gas chamber A. Then, press-fit the tail plug 5 using the tail plug press-fitting rod B. Note that, if necessary, the fixation of the tail plug main body 7 by press-fitting into the ink cylinder 1 may be reinforced by mechanical fixing means such as caulking or crushing, or chemical fixing means such as adhesion with an adhesive or welding.

This device constructed as described above has a diameter slightly larger than the inner diameter of the ink cylinder 1 and a fitting hole 9 on the rear end surface.
Tail plug tip body 6 made of a rubber-like elastic body formed with
and a tail plug body 7 which has a protrusion 8 that fits into the fitting hole 9 of the tail plug tip body 6 and is fixed within the rear end of the ink cylinder 1. has a circumferential groove 8A at the base and forms a truncated conical surface 8B that gradually narrows toward the distal end, and the fitting hole 9 matches the shape of the fitting protrusion 8 and is slightly smaller than the fitting protrusion 8. The fitting protrusion 8 is fitted into the fitting hole 9, and the locking protrusion 9A protruding from the edge of the fitting hole 9 is locked into the circumferential groove 8A. Plug tip body 6
A tail plug 5 is provided by integrating the tail plug body 7 with the tail plug body 7, and the tail plug 5 is press-fitted into the ink cylinder 1 in the pressurized gas chamber A to fix the tail plug body 5 to the ink cylinder 1. Since the tail plug tip body 6 is bulged in the radial direction by the pressurized gas pressure inside, the elastic force generated by the deformation of the tail plug tip body 6 due to the press fit causes the circumferential side of the tail plug tip body 6 to bulge in the ink cylinder 1.
The inner surface of the ink cylinder 1 is tightly sealed, and pressurized gas is sealed inside the ink cylinder 1. Moreover, since the tail plug 5 is fixed by press-fitting the tail plug main body 7 into the ink cylinder 1, the tail plug 5
There is no risk of it being extracted. Further, since no other fixing means is required, assembly becomes easy.

Since the tail plug main body 7 and the tail plug tip body 6 are fitted and integrated through the fitting protrusion 8 and the fitting hole 9, the press-fitting operations can be performed separately, and the effort required to handle them separately can be saved. Assembly is easy and quick.
Furthermore, in the case of press-fitting the tail plug tip body 6 and the tail plug body 7 individually, when the tail plug tip body 6 and the tail plug body 7 are overlapped, their centers are different, making the press-fitting difficult and time-consuming. Since the fitting hole 9 and the fitting protrusion 8 restrict the movement of the tail plug tip 6 and the tail plug main body 7 in the direction orthogonal to the center line, press-fitting is easy.

In addition, the fitting protrusion 8 of the tail plug main body 7 has a substantially conical surface 8B formed at its tip, and the fitting hole 9 is formed to match the outer diameter of the fitting protrusion 8. The fitting protrusion 8 is fitted, and the locking protrusion 9A protruding from the hole edge of the fitting hole 9 is locked to the circumferential groove 8A to close the tail plug tip 6.
The tail plug body 7 is integrated with the tail plug body 7 to provide the tail plug 5, and the tail plug 5 is press-fitted into the ink cylinder 1 in the pressurized gas chamber A, and the tail plug body 7 is fixed to the ink cylinder 1. The sealing of the gas body becomes even more reliable.

That is, the tail plug tip body 6 is moved by the internal pressurized gas body.
is pressed toward the rear end, and the deformation of the tail plug tip body 6 due to this pressing is guided by a truncated conical surface 8B formed at the tip of the fitting protrusion 8 so as to become gradually narrower toward the tip. This occurs in the form of pressing toward the inner wall of the ink cylinder 1, and the circumferential side surface of the tail plug tip 6 made of a rubber-like elastic body is brought into even stronger contact with the inner wall of the ink cylinder 1, thereby sealing the pressurized gas body. (See Figure 4).

To explain this further, the fitting hole 9 of the tail plug tip body 6 is made into a slightly larger cavity than the fitting protrusion 8 of the tail plug body 7, and both have a truncated conical shape. The tail plug main body 7 fixed in the rear end of the cylinder 1 and the pressurized gas pressure in the ink cylinder 1 come to strongly clamp the tail plug tip 6 at its tip, which causes the tail plug tip 6 to This is because it provides a bulging effect in the radial direction. Therefore, the rubber-like elastic body is resistant to deterioration over time, and the sealing effect is greater than that of conventional ones, making it possible to seal gases at higher pressures.

As explained above, according to this invention, it is easy to assemble, the rubber-like elastic body is resistant to deterioration over time, the effect of keeping the pressurized gas body sealed is maintained, and the sealing of the high-pressure gas body is further improved. This has various effects that are extremely useful in practice, such as making it possible to

[Brief explanation of drawings]

The drawing shows one embodiment of this invention.
The figure is an overall partially cutaway front view, Figure 2 is a partially cutaway front view schematically showing the assembled state, Figure 3 is an enlarged sectional view of the main part, and Figure 4 is a tail plug tip formed by the pressure of the pressurized gas body. FIG. DESCRIPTION OF SYMBOLS 1... Ink cylinder, 2... Chip, 3... Ink, 4... Float, 5... Tail plug, 6... Tail plug tip, 6A... Chamfered portion, 7... Tail plug body, 8...
...Fitting protrusion, 8A... Circumferential groove, 8B... truncated conical surface, 9... Fitting hole, 9A... Locking protrusion, A... Pressurized gas chamber, B... Tail plug press-fitting rod .

Claims (1)

[Scope of utility model registration request] In a gas pressurized ballpoint pen, the tail plug tip is made of a rubber-like elastic body with a diameter slightly larger than the inner diameter of the ink cylinder and a fitting hole is formed on the rear end surface, and the tail plug tip fits into the fitting hole of the tail plug tip. The fitting projection of the tail plug body is a truncated cone that has a circumferential groove at the base and gradually narrows toward the tip. The fitting hole is formed as a cavity that matches the shape of the fitting protrusion and is slightly larger than the fitting protrusion, and the fitting protrusion is fitted into the fitting hole, and the hole edge of the fitting hole is formed. A tail plug is provided by locking a locking protrusion protruding from the part into the circumferential groove to integrate the tail plug tip body and the tail plug body, and the tail plug is press-fitted into the ink cylinder in the pressurized gas chamber. A gas pressurized ballpoint pen characterized in that the tail plug body is fixed to an ink cylinder, and the tail plug tip body is bulged in the radial direction by pressurized gas pressure inside the ink cylinder.