JPS5845114Y2 - Notsuku style writing instrument - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a knock-type writing instrument, and particularly relates to a knock-type writing instrument with an improved knock part.

In writing instruments such as mechanical pencils that have a knock rod at the rear end of the shaft, the knock rod slides inside the barrel to feed out the lead. Or, even if the knock part of the knock rod has the same diameter as the outer cylinder, the part that slides inside the outer cylinder still needs to be made thinner, so a constricted part will be created between the outer cylinder and the knock part. , these were major constraints in designing the appearance of writing instruments.

The present invention was developed with the aim of improving the above-mentioned conventional problems.The present invention is designed so that the sliding part of the knock rod can be stored in the outer cylinder when not in use, and can be used as a writing instrument. To provide a knock-type writing instrument whose appearance can be designed into an unprecedented neat form.

Embodiments of the present invention will be described below with reference to the drawings.

The embodiment shown in the figure shows the case where the present invention is applied to a knock-type mechanical pencil, and FIG. 2 shows an enlarged cross-section of the main part with the knock bar in the retracted state.

A core tube 2 is inserted into an outer tube 1 constituting the shaft tube, and a sliding tube 3 is fitted and connected to the rear end of the core tube 2.

This sliding tube 3 is secured to the outer tube 1 by engagement between a key groove 4 formed in the axial direction of the inner circumferential surface of the outer tube 1 and a key 5 protruding from the outer surface of the sliding tube 3. On the other hand, it is non-rotatable and is fitted so as to be slidable in the axial direction, and the small diameter shaft portion 7 of the knock rod 6 is fitted into the rear part thereof.

A projection 8 is formed on the outer periphery of the small diameter shaft portion 7 of the knock rod 6, and this projection 8 is fitted into a groove formed in the peripheral wall 3a of the sliding tube 3.

As shown in the plan view in FIG. 3, the shape of the groove includes a vertical groove 9 that extends in the axial direction and allows the protrusion 8 to move freely in the axial direction, and a vertical groove 9 connected to one side of the vertical groove 9. It consists of first and second engaging grooves 10.11 which are provided and recessed and spaced apart in the axial direction.

The knock rod 6 includes a sliding shaft portion 12 that is provided following the small diameter shaft portion 7 and slides on the inner surface of the outer cylinder 1, and a sliding shaft portion 12 that is connected to the sliding shaft portion 12 and has an outer diameter equal to that of the outer cylinder 1. The protrusion 8 has a knock part 13 having a first engagement groove 10.
When the knock part 13 is engaged with the outer cylinder 1, the step surface 13a of the knock part 13
It is formed in such a size that it can come into contact with the rear end surface of.

The sliding tube 3 and the knock rod 6 are connected by a coil spring 14 interposed therebetween.

This coil spring 14 has a pressing force that constantly presses the knock rod 6 in the protruding direction, and a pressing force that presses the knock rod 6 in the direction in which the protrusion 8 is in the first position.
The second retaining groove 10.11 has a coiled torsion spring structure connected to provide a rotational force in the direction of insertion.

The lead feeding mechanism of the mechanical pencil in the illustrated embodiment has a fifth
As shown in the enlarged cross section, a movable tube 15 is inserted into the outer tube 1, and the collar 15a of the movable tube 15 and the core tube 2
A first spring 16 for feeding out the core is interposed between the tip and the tip.

The base of a lead chuck 17 is fixed to the tip of the core tube 2, and the tip of the lead chuck 17 is connected to the movable tube 15.
A chuck tightening ring 19 is mounted on the outer periphery of the chuck portion 17H of the protruding portion, and when the lead chuck 17 is retracted, the chuck portion 17 Tighten a and tighten core 2.
It is designed to hold 0.

A relatively weak second spring 21 is interposed between the rear end of the movable barrel 15 and the stepped portion 1a of the outer barrel 1, and when excessive writing pressure is applied to the lead 20, the lead chuck 17 The movable cylinder 15 moves backward against the spring 21 through the chuck tightening ring 19 to absorb the pressure and prevent the core from breaking.

Then, the chuck tightening ring 19 and the lead chuck 17
, the movable tube 1 to which the core tube 2 is attached via the first spring 16
5 and the second spring 21 interposed between the movable cylinder 15 and the outer cylinder 1 constitute a core feeding mechanism, which can be installed as one part.

Since the present invention has the above-mentioned configuration, when the writing instrument is not in use, when the knock rod 6 is pushed in against the coil spring 14 until the stepped surface 13a of the knock part 13 touches the rear end surface of the outer cylinder 1, the knock The protrusion 8 of the small diameter shaft portion 7 of the rod 6 reaches the position of the first engagement groove 10, and the torsional force of the coil spring 14 causes the knock rod 6 to rotate in the direction of the arrow in FIG.
It fits into the first engagement groove 10 as shown.

As a result, even when the knock rod 6 receives the elastic force of the coil spring 14, it does not return due to the engagement between the protrusion 8 and the first engagement groove 10, and as a result, the sliding shaft portion 12 of the knock rod 6 1, the knocking part 13 becomes continuous with the rear end of the outer cylinder 1, and maintains an outer shape that has a sense of unity with the outer cylinder 1.

Next, when writing, move the dowel bar 6 to the coil spring 1.
When the protrusion 8 is turned in the direction opposite to the arrow in FIG. 4 against the torsional force of the coil spring 1
4, it is projected to the position shown by the two-dot chain line in FIG.

At this time, the protrusion 8 comes to the position of the second engagement groove 11, so
The torsional force of the coil spring 14 causes the protrusion 8 to move into its engagement groove 11.
The knock portion 13 is held in a state protruding from the rear end of the outer cylinder 1.

When the knock part 13 is knocked in this way, the sliding tube 3 moves forward via the protrusion 8, the core tube 2 connected thereto advances, the lead chuck 17 moves forward, and the lead 20 moves forward by a predetermined length. The core 20 is then fed out.

To retract the knock rod 6 after writing, turn the knock rod 6 in the direction opposite to the arrow in FIG. If it is pushed in after being released, the protrusion 8 fits into the first engagement groove 10 as described above, and the retracted state can be achieved.

Therefore, according to the present invention, the knock rod can be stored in the outer cylinder of the shaft part when not in use, so even if the knock part of the knock rod is made the same thickness as the outer cylinder, a constricted part will not appear. It has an appearance that is essentially integrated with the outer cylinder, which eliminates design constraints.

Also, when it comes to retracting or protruding the knock rod, just turn it slightly and it will automatically lock in that position.
This has the effect of not causing any troublesome operation.

In addition, although the embodiment shown in the figures has been described with reference to the case where the present invention is applied to a mechanical pencil, it is also possible to apply it to other types of knock-type ballpoint pens and the like.

Further, the coil spring 14 may not be used.

[Brief explanation of drawings]

Fig. 1 is an external view showing an example of a mechanical pencil to which the present invention is applied, Fig. 2 is an enlarged sectional view of its main parts, Fig. 3 is a plan view of the same part, and Fig. 4 is a cross section taken along line IVIV in Fig. 2. Figure, 5th
The figure is an enlarged sectional view of the core feeding mechanism section. 1... Outer tube, 2... Core tube, 3...
...Sliding tube, 6...Knotting rod, 7...
Small diameter shaft portion, 8...Protrusion, 9...Vertical groove,
10...First engagement groove, 11...Second
Engagement groove, 12...Sliding shaft portion, 13...
・Knock part, 14... Coil spring, 15...
...Movable tube, 16...First spring, 17...
...Lead chuck, 18...Tip cap, 19...Chuck tightening ring, 20...
- Core, 21... Second spring.

Claims (1)

[Scope of utility model registration request] A sliding cylinder 3 is fitted into the shaft outer cylinder 1 so as to be slidable in the axial direction and non-rotationally and moves the core feeding mechanism, and a sliding cylinder 3 is fitted into the rear end of the outer cylinder and has the same diameter as the outer cylinder. is equipped with a knock rod 6 having a knock portion with an outer diameter close to that of the knock rod, and the inner end small diameter shaft portion of the knock rod is slidably inserted into the rear inside of the sliding tube, and the peripheral wall of the sliding tube is provided with a knock rod 6. A vertical groove 9 extending in the axial direction into which a projection formed on the outer periphery of the end of the small diameter shaft part fits, and a first engagement into which the projection can fit when the knock part is brought into close contact with the rear end surface of the outer cylinder. A knock-type writing instrument formed with a groove 10 and a second engagement groove 11 into which the protrusion can fit when the knock bar protrudes to the knock position.