JPH068689A - Expansion and contraction type ball-point pen - Google Patents

Abstract

PURPOSE:To contract an expanded shaft cylinder into a contracted shaft cylinder keeping a condition in which a ball head is projected from a head shaft irrespective of the length of the shaft cylinder. CONSTITUTION:In a writing instrument in which a shaft cylinder A is expandable, a ball head (b) can be projected from a head shaft 1 after the contracted shaft cylinder A being expanded, and the shaft cylinder A can be contracted with the ball head (b) kept in a projected state. The maintenance of the condition of the expanded shaft cylinder A is carried out by the operation of the relative revolution of the half part of the shaft cylinder A, and the projection and retreat of the ball head b and the expansion and contration of the shaft cylinder A are conducted by the operation of sliding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a writing instrument having a barrel whose extension and contraction are adjustable, that is, a so-called telescopic writing instrument.

[0002]

2. Description of the Related Art A writing instrument is known in which a front shaft and a rear shaft are slidably fitted to each other and a barrel is configured to be adjustable in expansion and contraction.
(For example, Japanese Unexamined Patent Publication No. 61-202894, Jikken 2
-17910 gazette etc.). The former JP-A-61-20
According to the proposal of Japanese Patent No. 2894, the ball tip of a ball-point pen can be freely retracted and retracted by expanding and contracting the shaft tube, and the shaft tube is extended at the time of use, and at the same time the ball tip is projected from the front shaft to be in a writing state. It is convenient to shorten the tube and at the same time pull the ball tip into the front axle to make it portable. However, it is not possible to make the ball tip protrude from the front axle after the axle cylinder is once extended.If the extended axle cylinder is shortened while the ball tip is protruding from the front axle, the hook body and There is a problem in that there is a risk that the engagement with the suction engagement portion at the rear end of the cylinder may be disengaged, and the ball tip protruding from the tip axle may be set in the tip axle. Further, according to the latter proposal of Japanese Utility Model Publication No. 2-17910, when the barrel is extended, the ball tip cannot be projected at all from the leading shaft.

The present invention has been made in view of such a situation. The ball tip can be projected from the tip shaft regardless of the length of the barrel, and the ball tip can be projected from the tip shaft. An object of the present invention is to provide a telescopic ballpoint pen capable of shortening an elongated barrel.

[0004]

[Means for Solving the Problems] In order to achieve the above object, in the means of the present invention, the front and rear shafts are relatively slidably fitted to each other so that the barrel can be adjusted for expansion and contraction. In the writing instrument configured as described above, the ball tip is configured to be able to project from the tip shaft after the shortened barrel is extended, and the shaft tube is configured to be shortened while maintaining the ball tip projection from the tip shaft. Is.

[0005]

After the shortening barrel is extended, the ball tip is projected from the leading shaft, and the barrel is shortened while maintaining the ball tip protruding from the leading shaft.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The rear shaft 2 is slidably fitted to the outer circumference of the front shaft 1 to form a shaft cylinder A which is adjustable in expansion and contraction, and the center core spring 4 is fitted to the front metal 3 side portion of the front shaft 1. The core 5 is always elastically urged in the retracting direction (upward in FIG. 1).

The base end side of the core 5 having the ball tip b (the end side opposite to the ball tip) is fitted into the knock 6, and the base end side of the knock (the end opposite to the core). Part side) is slidably fitted to the knock holder 7, and this knock holder is arranged in the rear shaft 2 and protrudes from the base end portion of the rear shaft 2 for fitting in the rear shaft 2. The spring 8 always elastically urges the knock holder 7 in the direction of retracting the ball tip b.

The knock 6 and the knock holder 7 constitute an engaging claw 9 at the tip of the knock 6 so that the knock 6 and the knock holder 7 do not escape from the shaft cylinder A even when the knock 8 is elastically urged. The engagement step portion 10 of the shaft 1 is engaged.

A plurality of feed teeth 12 for the engaging claws 9 and for the rotor 11 are formed in the circumferential direction toward the front metal 3 side at the front metal side portion of the inner peripheral surface of the front shaft 1, and the feed is performed. A deep sliding groove 13 and a shallow sliding groove 14 which are long in the axial direction reaching the engagement step portion 10 from the teeth are formed and alternately arranged in the circumferential direction.
3 is fitted to the peripheral surface of the rotor 11, and the shallow sliding groove 1
4 is fitted to the peripheral surface of the engaging claw 9, and both sliding grooves 13 and 14
The engaging claw 9 and the rotor 11 can be slid along.

Thus, the tip end surface (lower surface in FIG. 1) of the engaging claw 9 is circumferentially formed into a zigzag shape (continuous shape of peaks and valleys), and the tip end portion of the rotor 11 (upper part in FIG. 1). A plurality of follower teeth 15 for the engaging claw 9 and the feed dog 12 are formed on the. These follower teeth are classified into those formed on the protrusions protruding in the axial direction and those formed between the follower teeth 15 on the protrusions.

The rotor 11 rotates in one direction when the follower tooth 15 is followed by the zigzag portion of the engaging claw 9 and engages with the feed dog 12 to cause the ball tip b to protrude from the tip shaft 1, or The engagement with the feed dog 12 is disengaged, and the elastic force of the center spring 4 slides along the deep bottom sliding groove 13 and the shallow bottom sliding groove 14 in the retracting direction of the ball tip b, and the ball tip b. Is pulled into the front axle.

The front shaft 1 and the rear shaft 2 are rotatably fitted to each other, and the front half and the rear half of the barrel are relatively rotatable.
This structure will be described below.

The knock 6 fitted into the shaft cylinder A is provided with a sliding groove 16 in the axial direction at a portion facing the outer peripheral surface of a fitting portion into which the center core 5 is fitted. It is configured so as not to rotate by engaging with the engaging portion 17 provided inwardly projecting to the base portion, and the cross-sectional shape of the portion closer to the base end than the fitting portion for the core 5 is fan-shaped to the portion facing the shaft peripheral surface. The locking portion 18 is formed in a projecting cross-sectional shape (see FIG. 2), and the lateral cross-sectional shape of the portion fitted into the knock holder 7 is formed into a slightly small-diameter shaft portion and the shaft portion peripheral surface facing portion thereof is formed. A slightly smaller fan-shaped locking portion 19 is formed in a protruding shape on the cross section. (See Figure 3)

Then, the base end side portion including the base portion of the fitting portion for the core 5 of the knock 6 is fitted into the holder guide 20, and the knock 6 is slidably fitted into the holder guide. The holder 7 is fitted and the knock 6, the knock holder 7, and the holder guide 20 are associated with each other for rotation. (See Figure 1, Figure 2, Figure 3, etc.)

In the knock 6, the fan-shaped engaging portion 19 is fitted in the fan-shaped rotation groove 21 on the inner peripheral surface of the knock holder 7, and the engaging convex portion 22 is provided so as to project outward at a position facing the outer peripheral surface of the knock holder.
Is engaged with a vertically long engaging groove 23 of the holder guide 20 which is press-fitted into the rear shaft, and the vertically long engaging projection 24 formed outwardly on the outer side of the engaging groove is formed on the inner peripheral surface of the front shaft 1. If the front shaft 1 or the rear shaft 2 is engaged with the longitudinal engaging groove 25 provided at the base end facing portion and one of the front shaft 1 or the rear shaft 2 is rotated in the direction of the arrow shown in FIG. Holder guide 20 press-fitted into 2
Then, the knock holder 7 engaged with this holder guide rotates in synchronization.

When the ball tip b projecting from the tip shaft 1 is to be retracted in a state where the shaft cylinder A shown in FIG. 4 is shortened, the knock 6 is pushed and the engaging claw is engaged as described above. 9, the core 5 is drawn in by cooperation of the rotor 11, the feed dog 12, the core spring 4, the deep slide groove 13, the shallow slide groove 14, and the like, and the ball tip b is in the front shaft 1. Immerse yourself in. When the knock 6 is pushed again, the writable state shown in FIG. 4 can be obtained by the re-cooperation of the above-mentioned members. Therefore, the ball tip b can be retracted from the front shaft 1 after the shaft cylinder A is shortened.

From the state shown in FIG. 4, the front shaft 1 or the rear shaft 2 is stretched to extend the barrel A into the state shown in FIG. 1, and then the rear shaft 2 and the vertically elongated ridges 24 of the holder guide 20 are moved first. Axis 1
5 is rotated in a direction opposite to the direction of the arrow in FIG. 5 in the longitudinal engaging concave groove 25 to lock the projection 24 on the locking step portion 26 of the front shaft 1, and the relative axial direction of the barrel A. If the knock 6 is pushed after the sliding is disabled, as described above, the engaging claw 9, the rotor 11, the feed dog 12, the core spring 4, the deep slide groove 13, the shallow bottom are provided. The ball tip b can be projected from the front shaft 1 as shown in FIG. 1 by cooperation of the sliding groove 14 and the like.

Then, when the knock 6 is pushed again in the projecting state of the ball tip b shown in FIG.
The rotor 11 rotates by the cooperation of 11, 12, 4, 13, 14, etc., and the rotor 11 slides in the deep slide groove 13 in the ball leading-in direction by the elastic force of the center core spring 4. Then, the ball tip b is immersed in the tip shaft 1. Therefore, the ball tip b can be retracted from the front shaft 1 after the shaft cylinder A is extended.

In the extended state of the barrel A shown in FIGS. 1 and 3 and the protruding state of the ball tip b, the front half or the rear half of the barrel A is relatively moved in one direction of the arrow shown in FIG. By rotating, the vertically elongated ridges 24 of the holder guide 20 are rotated in the same direction in the vertically elongated recessed grooves 25 of the front shaft 1 to move the ridges 24.
When the lock is released from the locking step portion 26 of the front shaft 1 to release the lock, the vertically long ridge 24 becomes slidable in the vertically long engaging groove 25 in the axial direction. The rear half portion can be slid relative to each other in the axial direction to fit the shortened barrel shown in FIG. Therefore, the barrel A can be shortened while maintaining the protruding state of the ball tip b.

In the figure, reference numeral 27 is an unrotatable sleeve having a rotation stopping portion (not shown) for preventing excessive rotation of the rotating member. In addition, the detent portion is appropriately configured such as an inward protrusion and an inward claw portion.

[0021]

As is apparent from the above description, according to the present invention, it is of course possible to make the ball tip project after the shaft tube is shortened, and it is also possible to make the ball tube tip first after the shaft tube is extended. It can be projected from the shaft, and the barrel can be shortened while the ball tip is projected. Therefore, it is possible to improve the conventional technique and achieve the intended purpose.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a state in which a barrel of a ballpoint pen of the present invention is extended and a ball tip is projected.

FIG. 2 is a cross-sectional plan view taken along the line AA of FIG.

FIG. 3 is a cross-sectional plan view taken along the line BB of FIG.

FIG. 4 is a vertical cross-sectional front view showing a state in which the shaft cylinder is shortened and a ball tip is projected.

5 is a cross-sectional plan view taken along the line CC of FIG.

FIG. 6 is an exploded perspective view of main members.

[Explanation of symbols]

1 ... Front shaft 2 ... Rear shaft 4 ... Core spring 6 ... Knock 7 ... Knock holder 8 ... Knock spring 20 ... Knock guide

Claims (1)

[Claims] 1. A writing instrument in which a front shaft and a rear shaft are relatively slidably fitted to each other so that the shaft cylinder is adjustable in expansion and contraction. A retractable ballpoint pen characterized by being configured to be capable of projecting from a shaft barrel and being capable of shortening a barrel while maintaining the projection of the ball tip from the tip shaft.