JPS61279599A - Propelling pencil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a mechanical pencil with improved writing feel.

Mechanical pencils are equipped with a lead protection pipe such as a stainless steel pipe at the tip of the tip to protect the lead, but if the edge of the pipe comes into contact with the paper surface when writing, Frictional resistance occurs between the pipe and the paper surface, and especially when the pipe is retracted into the barrel while writing, such as with an automatic mechanical pencil, the pipe may not retract smoothly and may feel stuck. It was hot.

The present invention eliminates such drawbacks and has various other features, and includes a core guide pipe that protects the lead core in an actuator that is movable in the axial direction at the tip of the shaft cylinder. In addition, the pipe is made of a plastic material with a small coefficient of friction to reduce friction between the paper surface and the tip of the pipe, allowing smooth movement of the actuator and enabling smooth writing.

Although the present invention can be applied to various types of mechanical pencils, an example in which it is applied to an automatic mechanical pencil will be described below.

In the figure, a holder (2) is screwed (3) to the tip of the shaft cylinder (1), and a cap (4) is screwed to the holder (3) (n1).
5) It is shi. Inside the cap, there is provided an actuator (7) movable in the axial direction, which elastically holds the lead core (6) by friction and urges the tip to protrude from the tip of the barrel. Further, movement control means and other means are provided within the holder to allow the lead core to move forward and prevent it from moving backward.

The above-mentioned actuator (7) has an elastic ring (8) made of an elastic material such as rubber or synthetic resin fixed to the rear part so as to elastically hold the lead core (6) by friction, and the tip has an elastic ring (8) made of elastic material such as rubber or synthetic resin. A lead-core guide pipe (9) made of a plastic material with a low modulus is provided. In the figure, the plastic materials include polyacetal resin and polyamide resin I.
IW, 7-carbon resin, and other thermoplastic materials with a low coefficient of friction are used. In the case of polyacetal resin and polyamide resin, the friction coefficient is approximately θ, /j ~ θ,
2T: Ant, in the case of conventional stainless steel bike 1 (approximately θ.3
7 to θ, significantly smaller than 41). In the figure, the entire body including the core guide pipe is integrally molded from a glass material, but the pipes may be made separately and combined.

The pipe preferably has a tapered surface α0 at its tip, and is slidably inserted into a hole αυ provided in the cap (4). The rear part of the actuator (7) is fitted into a stopper (L5) fixed inside the base, and the flange (to) is fixed by a spring α4 provided between the 7 lange bolt provided in the middle part and the stopper Q'4. The actuator is urged to move forward and downward until it comes into contact with the stepped part of the mouthpiece.The actuator is activated when the tip of the lead guide pipe hits the paper surface during writing and is pushed backward. Along the axial direction, the above 7 langes (to) stoppers (6
) back up until it hits the front end of the head.

When the pressing force pushing the tip of the pipe backward is removed, the actuator returns to the forward position by the spring Q41. Along with this, the lead core held by the elastic ring (8) moves forward. The cap (4) is preferably made of a plastic material such as polyacetal resin or polyamide resin, which has the same effect as the core guide pipe.

The movement control means can have various configurations, but in the figure, it is configured as follows. Slide sleeve a movable in the axial direction inward of the holder (2)
A chuck is provided within the slide sleeve to allow the lead core to move forward and to prevent it from moving backward. The chuck is constructed by combining two chuck elements (7) facing each other, and has a taber αlJ on the inner surface of the slide sleeve θη on the outer periphery of the front part.
A ball (01) is interposed between the ring and the chuck element. The front end of the above/g ■ is the chuck stopper (
A chuck spring (C) is provided between the rear end of the mandrel and a flange (E) provided at the rear of the chuck element (G). In addition, the above two chuck elements Q
119 is a half-split piece of a cylindrical body with a clamping part formed on the inner surface of the front part, and the chuck elements are assembled facing each other with a narrow space between them to form the front σ) combination of the above-mentioned 7 lunges (to). A protrusion provided on the surface engages with a receiving groove (not shown), and the engaging portion is used as a fulcrum to enable the device to swing freely. As a result, when the rear end of the chuck element is pushed or pulled forward, the flange is pressed by the chuck spring, so that the front part opens and releases the lead core from being clamped. , and when it returns to the retracted position shown in the figure, the clamping part can be closed by the action of the ring (4) and the ball Q1) and the lead core can be clamped. 236θ/otsu, same!9-/ and 26guta).

A sleeve cap (c) is fitted to the rear end of the slide sleeve 0η, and a knock (g) is fitted into the sleeve cap (c), and the small protrusion is pressed against the side of the knock. It is movable. A spring holder (c) is provided on the rear outer periphery of the knock, and a knock spring is provided between the spring holder and the rear end of the holder (2). A wick tank (1) is attached to the rear end of the knock.

Lead core (6) stored in the above core tank (G) 1. Ma,
When the shaft cylinder (1) is in an upright position, if its tip reaches the clamping part of the chuck and stops, or if you knock the rear end of the core tank, the slide sleeve (F) will move forward and the chuck stopper (F) will move. After contacting the rear end of the actuator, the knock (c) further advances against the pressure force of the small protrusion □□□, pushes the rear end of the chuck and moves the chuck forward, and the chuck clamping portion Open the lead core and insert the actuator (7)
Move the elastic ring forward by itself until it hits the 8th ring.

When the knock at the rear end of the lead tank is stopped, the slide sleeve etc. will return to the state shown in the figure by the knock spring wire and the chuck spring ◇, so when the rear end of the lead tank is knocked again, the lead core will be clamped by the chuck. Therefore, when the slide sleeve moves forward, it moves forward to a position where it enters the inside of the elastic ring (8). Thereafter, by repeating this operation, the lead core protrudes from the tip of the lead guide pipe (9) and writing can be performed.

When writing, the tip of the lead guide pipe (9) comes into contact with the paper surface C31) together with the lead lead, but since the pipe is made of a plastic material with a low coefficient of friction, the contact part with the paper surface and the outer surface of the pipe The frictional force generated at each contact point from the opening edge of the hole αυ of the cap (4) to the wall surface, and the contact point between the inner surface of the pipe and the lead core is small, and the actuator moves back smoothly, and the contact point between the inner surface of the pipe and the lead core is small. The tip of the bi 1 is worn out at the contact area, and there is no rubbing feeling like in the past, and the writing taste is very good. When you stop writing and release the tip from the paper surface, the actuator (7) moves forward while holding the lead lead by the spring α, and at this time, the chuck also moves together with the lead lead to release the grip of the lead lead. Therefore, the lead core is automatically extended to the forward position together with the actuator.

Since the present invention is constructed as described above, it has a very good writing feel, and the structure of the actuator is simple and can be manufactured economically.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a sectional view and FIG. 2 being an enlarged sectional view of the actuator portion mainly during use. 1... Shaft tube, 4... Base, 7... Actuator,
8...Elastic ring

Claims (1)

[Claims] It has an actuator that is biased to be movable in the axial direction so that its tip protrudes from the tip of the barrel, and the actuator has an elastic ring at the rear that elastically holds the lead core by friction. A mechanical pencil with a lead guide pipe made of plastic material with a low coefficient of friction at the tip.