JPH05596A - Writing utensil - Google Patents

Abstract

PURPOSE:To provide a writing utensil hermetically sealed in such a state that the writing part thereof present at a retracted position is substantially perfectly isolated from the open air. CONSTITUTION:A writing part main body 4 having a writing part 7 is received in an inner cylinder 2 opened at both ends thereof through the first spring 10 mounted on said main body so as to be able to advance and recede between a writing position and a retracted position. The inner cylinder 2 is provided in a shaft main body 1 through a second spring 12 having elastic force smaller than that of the first spring mounted thereon so as to be able to advance and recede over a definite section in connection with the advance and recession of the writing part main body 4. A mechanism bringing the leading end opening of the inner cylinder 2 to a hermetically sealed state at the retracted position of the inner cylinder and bringing the same to an open state at the advance position thereof and a seal mechanism holding the gap between the inner wall of the inner cylinder 2 and the writing part main body 4 or the writing part 7 to an airtight state are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument such as a ballpoint pen and a felt-tip pen having a mechanism for moving a writing portion between a writing position and a retracted position.

[0002]

2. Description of the Related Art Conventionally, a writing portion such as a water-based ballpoint pen which is provided so as to be able to move forward and backward between a writing position and a retracted position is kept in a sealed state at the retracted position in order to prevent ink from disappearing. Although various writing instruments that are designed to be released from the sealed state when brought into contact with each other have been proposed, but none of them have been put to practical use and are merely suggestions.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to have a very simple structure and to seal the writing part in the retracted position in a substantially completely isolated manner from the outside air. There is no risk of the writing part being contaminated or damaged when moving forward or backward, and the writing part can be easily replaced without the need for a writing part with a special structure. It is intended to provide such a writing instrument.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention is to attach a writing portion main body 4 having a writing portion 7 to an inner cylinder 2 which is open at both ends, and a first spring 10 therein. The shaft body 1 is housed so as to be able to move forward and backward between a writing position and a retracted position, and the inner cylinder 2 is attached with a second spring having a smaller elastic force than the first spring. The writing section main body 4 is provided therein so that it can be carried forward and backward by a forward movement and a backward movement of the writing section main body 4, and a reduced diameter portion 20 is provided in the inner cylinder via a step portion 2a.
Is formed, and the end portion of the rubber-like elastic tube 21 is fixed to the inside of the diameter-reduced portion to form a diameter-reduced cylinder. Outside the diameter-reduced portion 20 and the elastic tube 21, a pair of leaf-spring-like elasticity is formed. The body 51 is fixed so as to face each other, and the reduced diameter portion 20 is provided on the front inner peripheral wall of the shaft body 1.
A cavity 60a through which a reduced-diameter cylinder consisting of the elastic tube 21 and the leaf spring-like elastic body 51 on the outer side thereof can freely pass, and a tapered cam surface 6 expanded toward the tip side of the shaft body 1.
0b and a rear end side vertical wall 60c are formed on the engaging portion 60, and the elastic body 51 is fixed to the front surface of the engaging body 50 having an inclined surface 50a corresponding to the tapered cam surface 60b. In the retracted position of the writing section main body 4 and the writing section 7, the elastic tube 21 is engaged by the engagement between the inclined surface 50a of the engaging body 50 and the tapered cam surface 60b of the engaging section 60.
The front end side of the elastic body 51 and the seal plate 5 is formed by the engaging body 50.
1a is attached and sealed from above and below, while the writing section main body 4 is moved forward to bring the writing section 7 to the writing position,
Due to the forward movement of the writing body, the inner cylinder 2 is carried along with the stepped portion 2.
At the time point when “a” advances until it comes into contact with the vertical wall 60c of the engaging portion 60, the inclined surface 50a of the engaging body 50 is disengaged from the engagement with the tapered cam surface 60b, the tip of the elastic tube 21 is released, and the writing is continued. When the part main body 4 is moved forward, the tip of the writing part 7 passes through the elastic tube 21, and the tip of the writing part projects from the opening 8 of the shaft main body 1 to bring the writing part main body 4 to the writing position. There is a writing instrument characterized by.

The present invention will be described based on the embodiments shown in the drawings.

[0006]

1 to 3 are sectional views showing a main part of a writing instrument according to the present invention, in which, for example, a knock-type or rotary-type mechanism for alternately changing the writing part between a writing position and a retracted position is omitted. is there. In the figure, reference numeral 1 is a shaft main body of a writing instrument, and an opening 8 through which the tip of the writing section appears is provided at the tip of the shaft body.

Reference numeral 4 denotes a writing portion main body having a writing portion 7, which has a first spiral spring 10 and one end of which is a step portion 2a of the inner cylinder 2.
It is mounted in a state in which the other end is supported by the seal member 11 provided on the stepped portion 4a of the writing portion main body 4, and is housed in the inner cylinder 2 so as to be able to move forward and backward. The seal member 11 is slidable with respect to the inner wall of the inner cylinder 2, and has a role of keeping the gap between the inner wall of the inner cylinder 2 and the writing section body 4 or the writing section 7 airtight.

Reference numeral 2 is an inner cylinder in which the second spiral spring 12 is mounted in the shaft main body 1 in a state where the writing portion main body 4 and the writing portion 7 are accommodated so as to be able to move forward and backward for a certain period. The spiral spring 12 has one end supported by a vertical wall 60c of an engaging portion 60, which will be described later. A diameter-reduced portion 20 is formed on the inner cylinder 2 through a step 2a, and an end of an elastic tube 21 such as a rubber tube is fixed inside the diameter-reduced portion to form a diameter-reduced cylinder. Reduced diameter portion 20 and elastic tube 21
An elastic body 51 such as a pair of upper and lower leaf springs is fixedly provided on the outer side of the above, as shown in the figure.

An engagement portion 60 is formed on the front inner peripheral wall of the shaft body 1, and a cavity 60a through which the elastic tube 21 and the elastic body 51 can freely pass, the shaft body 1 are formed in the engagement portion 60.
A tapered cam surface 60b that is widened toward the front end side and a vertical wall 60c on the rear end side. Elastic body 51
An engaging body 50 having an inclined surface 50a corresponding to the tapered cam surface 60b is fixed to the front surface of the end portion of, and a seal plate 51a is lined on the rear surface of the end portion of the elastic body 51.

In the writing instrument of the present invention, as shown in FIG. 1, the inclined surface 50a of the engaging member 50 and the tapered cam surface 60b of the engaging portion 60 are engaged with each other in the retracted position of the writing portion main body 4 and the writing portion 7. Thus, the tip side of the elastic tube 21 is
The elastic body 51 and the seal plate 51 by the engaging body 50 from above and below.
It is configured to be attached and sealed via a. Therefore, the writing portion 7 is substantially completely shielded from the outside air inside the inner cylinder 2.

In order to bring the writing unit 7 from the retracted position to the writing position, a knocking operation is performed to advance the writing unit 7 to the writing position by, for example, a knock mechanism (not shown) provided at the rear end of the writing unit main body 4. Then, the writing section body 4 advances in the direction of arrow B. Since the elastic force of the first spiral spring 10 is set stronger than that of the second spiral spring, first, the inner cylinder 2 should change its relative position with respect to the main body 4 of the writing part by advancing the main body 4 of the writing part. Without moving, the step portion 2a advances until it contacts the vertical wall 60c of the engaging portion 60 (FIG. 2). At this time, the inclined surface 50a of the engagement body 50 is disengaged from the engagement with the tapered cam surface 60b, so that the elastic tube 21 and the elastic body 51 are returned to their original state, and the diameter-reducing cylinder, that is, the tip of the elastic tube 21 is opened. It

When the writing portion main body 4 subsequently advances in the direction of the arrow B, the inner cylinder 2 is prevented from advancing, so that the tip portion of the writing portion 7 is compressed by the elastic tube while compressing the first helical spring 10. The writing section body 4 is brought to the writing position by passing through 21 and projecting the tip of the writing section from the opening 8 of the shaft body 1 (FIG. 3). When returning from the writing position of FIG. 3 to the retracted position of FIG. 1, the process is performed in the reverse order to the above, and in the retracted position, the writing portion 7 is substantially completely isolated from the outside air and is kept in a sealed state. ..

Although the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to these embodiments, and various design changes can be made without departing from the spirit of the present invention. Of course there is nothing you can do.

[0014]

As described above, according to the present invention, the structure is extremely simple, and the writing portion in the retracted position (storage position) can be sealed substantially completely isolated from the outside air, and the writing can be performed. Since the part does not have the risk of being contaminated or damaged, it can be used for a long period of time, and the writing part is extremely easy to replace due to its structure. Since it can be used, it is possible to provide a practical and inexpensive writing instrument.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part of an embodiment of the present invention, showing a state in which a writing part 7 is in a retracted position and is completely sealed from outside air.

FIG. 2 is a view showing that the writing part 7 advances from the position shown in FIG.
The inclined surface 50a of 0 is disengaged from the engagement with the tapered cam surface 60b, the elastic tube 21 and the elastic body 51 are returned to the original shape, and the diameter-reducing cylinder, that is, the tip of the elastic tube 21 is opened. ..

FIG. 3 shows that the writing section 7 advances from the position of FIG. 2 to the final position, and the tip of the writing section 7 passes through the elastic tube 21,
It is a figure which shows the state in which the writing-section tip was projected from the opening 8 of the shaft main body 1, and the writing-section 7 was brought to the writing position.

[Explanation of symbols]

 1 Shaft Main Body 2 Inner Cylinder 3 Opening 4 Writing Part Main Body 7 Writing Part 8 Opening 9 Flange 10 First Helical Spring 11 Sealing Material 12 Second Helical Spring 13 Air Hole 20 Reduced Diameter Part 21 Elastic Tube 50 Engaging Body 50a Slope 51 Elastic Body, 51a Seal Plate 60 Engaging Part 60a Cavity 60b Tapered Cam Surface 60c Vertical Wall

Claims (1)

1. A writing part main body 4 having a writing part 7 is attached to an inner cylinder 2 whose both ends are open, and a first spring 10 is attached to the writing part and the retracted position. Between the inner cylinder 2 and the second spring, which has a smaller elastic force than the first spring, is housed in the shaft main body 1 and the writing part main body 4 is provided so as to be carried forward and backward by a forward movement and backward movement of a predetermined section, and a reduced diameter portion 20 is formed in the inner cylinder through the step portion 2a, and an end portion of the rubber-like elastic tube 21 is provided inside the reduced diameter portion. To form a reduced-diameter cylinder, and the reduced-diameter portion 20
On the outer side of the elastic tube 21, a pair of leaf spring-like elastic bodies 51 are fixed to face each other, and on the front inner peripheral wall of the shaft main body 1, a reduced diameter tube composed of the reduced diameter portion 20 and the elastic tube 21 is formed. A cavity 6 that can freely pass with the outer leaf spring-like elastic body 51.
0a, an engaging portion 60 having a tapered cam surface 60b widened toward the tip side of the shaft body 1 and a vertical wall 60c on the rear end side is provided, and the tip end surface of the elastic body 51 is tapered. The engaging body 50 having the inclined surface 50a corresponding to the cam surface 60b is fixed, and the inclined surface 50a and the engaging portion 6 of the engaging body 50 are in the retracted position of the writing body 4 and the writing portion 7.
Due to the engagement with the tapered cam surface 60b of 0, the tip end side of the elastic tube 21 is sandwiched and sealed by the engaging body 50 from above and below via the elastic body 51 and the seal plate 51a, and the writing portion 7 is set to the writing position. The writing section main body 4 is advanced to bring the writing section main body 4 forward, and the forward movement of the writing section main body causes the inner cylinder 2 to be entrained so that the step portion 2a advances until it contacts the vertical wall 60c of the engaging portion 60. When the surface 50a is disengaged from the engagement with the tapered cam surface 60b, the tip of the elastic tube 21 is released, and when the writing section main body 4 is continuously advanced, the tip of the writing section 7 passes through the elastic tube 21.
A writing instrument characterized in that the writing section body 4 is brought to a writing position by projecting the tip of the writing section from the opening 8 of the shaft body 1.