JPH0245031Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a self-feeding sharp pencil whose lead lead is automatically fed out as it is consumed by writing.

Automatically dispensing type sharp pencils are known to have various configurations, but all of them have complex structures, and the lead core protrudes slightly forward from the tip of the cap's core protection pipe when being dispensed. In many cases, the lead core is slow to feed out and is difficult to use.

In order to solve this problem, the present invention is designed so that when the lead core is automatically fed out, it protrudes more quickly than the tip of the core protection pipe.

This will be explained below along with examples.

In the one shown in the figure, a lead core is elastically held in a base 2 attached to a barrel 1 by friction, and is biased so that its tip protrudes from the tip of the barrel.It is movable in the axial direction. There is a slider method. The slider means can have various configurations, but the one shown in the figure has a tip pipe 3 protruding from the tip of the base, and an actuator 4 is fixed to the rear end of the tip pipe. The actuator has an elastic ring 6 made of an elastic material such as rubber or synthetic resin fixed to the rear part thereof to elastically hold the lead core 5 by friction, and a holding cylinder 7 fixed to the base.
It is inserted so that it can move in the axial direction. A spring 10 is provided between the flange 8 provided at the front of the actuator and the inner step 9 of the holding cylinder to bias the actuator so that the tip pipe protrudes from the base. The actuator retreats in the axial direction until the flange 8 contacts the front end surface 11 of the holding cylinder 7 when the tip of the tip pipe is pushed rearward. When the pressing force pushing the tip of the tip pipe backward is removed, the actuator is returned to the forward position by the spring. Along with this, the lead core 5 held by the elastic ring 6 moves forward.

A cylindrical guide wall 12 is screwed to the rear of the cap 2 (left-hand thread). The guide wall is made of polyacetal or other plastic material, and has a male thread 13 on the outside for screwing the shaft cylinder 1, and a storage cylinder 14 is fitted on the inside so as to be movable in the axial direction along the guide wall. When inserted, the storage cylinder is urged forward by a spring 15, and movement control means is provided within the storage cylinder to allow the lead core to move forward and prevent it from moving backward.
A differential piece 16 is fitted to the front end of the storage tube 14, and a cap 17 is fitted to the rear end. The differential piece has an annular groove 18 in which a differential ring 1 that expands elastically is inserted, as shown in FIG.
9 is fitted. The differential ring is made of metal spring material, but could also be made of elastic rubber, plastic material, etc. The inner diameter of the guide wall facing the differential ring changes depending on the movement position of the storage cylinder 14 and the differential ring 19. That is,
When the storage tube is in the backward position, the guide wall portion 20 on which the differential ring 19 slides is formed to have a small diameter, and the differential ring is pressed against the small diameter guide wall portion to move the storage tube forward. is temporarily delayed, and the guide wall portion 21 in front thereof is formed with a large diameter via an inclined surface 22 to release the pressure of the differential ring, and in this state, the storage cylinder moves to the forward position. . Between the differential piece 16 and the rear end of the base 2, there is a spring 23 having a spring pressure weaker than that of the spring 15, so that the storage cylinder 14 is located at a substantially normal position in the use state.

The lead core movement control means can have various configurations. In the one shown in the figure, a cylindrical operating ring 25 having a tapered surface 24 that is inclined so that the diameter becomes larger at the front is mounted in a storage cylinder, and the cylindrical operating ring 25 is movable in the axial direction inward of the operating ring 25. A chuck 26 is inserted therein. The chuck is shown in Figure 4~
As shown in FIG. 6, it is composed of chuck elements 27, 27 which are divided into two parts in the axial direction, and when these chuck elements are combined, they form a hole 28 through which the lead core 5 is inserted, and the front part of the through hole is has a chevron-shaped protrusion 29 for gripping the lead core, and has a recess 31 on the outer surface for receiving and supporting the ball 30. The chuck element has a locking protrusion 32 having an arcuate tip at the rear of the intermediate portion.
and a receiving groove 33 whose bottom part is arcuate, and when facing each other, the engaging protrusions of each chuck element are engaged with the opposing receiving grooves, and the front ends are assembled so as to be openable. There is a flange 34 on the outer periphery of the chuck element behind the locking protrusion, etc., and a spring 35 is provided between the flange and the operation ring 25, and the chuck is urged rearward by the action of the spring. The front end of the chuck is normally closed lightly to hold the lead core. An inclined wall 36 is formed at the rear of the chuck element, and a hook piece 38, which faces the inclined wall and has a pressing edge 37 at its front end, is inserted into the cap 17. The Notsukukoma 3
8 has a lead core insertion hole 39, the front shoulder 40 abuts the front end 41 of the cap 17, and the rear shoulder 4
2 engages with the rear end flange 43 of the guide wall 12, and the spring 15 is disposed between it and the cap 17.
is attached, and a lead-cored storage tank 44 is attached to the rear, and the rear end of the storage tank is tapped.

The tip of the lead core 5 that has come out of the storage tank 44 has reached the insertion hole 28 of the chuck 26. At this point, the tank is knocked and the pressing edge 37 of the knock piece 38 is pressed against the inclined wall of the chuck. 36 and the chuck is moved forward, the front end of the chuck opens and the lead core automatically falls to a position where it abuts the elastic ring 6 of the slider means. When the hitch is stopped, the chuck and the hitch piece return to the rear, and the lead core 5 is gripped by the chuck. When the tank is knocked again, the lead core moves forward a little further while being held by the chuck, and its tip gradually enters the elastic ring 6. Thereafter, by repeating the above operations, the lead lead gradually advances and protrudes from the tip of the tip pipe 3, so that writing can be performed.

When the tip pipe 3 hits the paper surface while writing and the slider means moves backward, the actuator 4
The rear end of the storage cylinder 14 touches the differential link 16, and the storage cylinder 14 moves rearward. In this state, the operating ring 25 moves back as the storage tube moves back, so
The gripping action of the chuck is released, so that when the lead core is removed from the surface of the paper, the lead core is held by the elastic ring 6 of the slider means and moves forward with the forward movement of the slider means. When the storage tube 14 is pushed to the retracted position, the differential ring 19 moves to the small diameter guide wall portion 2, as shown by the solid line in FIG.
0 and is pressed against the guide wall, the forward movement of the housing cylinder 14 by the spring 15 is temporarily braked. The forward movement of the storage tube is thus delayed, but by separating the lead core from the surface of the paper as described above, the lead core protrudes to the same position as the front end of the tip pipe 3 as the slider means moves forward. There is. The sliding contact position between the differential ring 19 and the guide wall portion 40 is determined by the action of the spring 15 on the housing cylinder 14.
gradually moves forward, and the differential ring 19 is eventually released from the crimping in response to the guide wall portion 21 having a large diameter (dashed line in FIG. 2). As a result, the storage cylinder 14 becomes free and quickly advances to the forward position due to the action of the spring 15. During this time, the chuck is gripping the lead core, so the tip pipe 3
The lead core 5, which is located at the same position as the front end of the pipe, advances further and its tip reaches the tip of the pipe 3 as shown in FIG.
protrudes slightly from the tip. In this way, the lead core can be quickly protruded from the tip pipe, making it easy to use.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a partially omitted sectional view, FIG. 2 is an enlarged sectional view mainly of a part of the differential link, FIG. 3 is an enlarged perspective view of the differential ring, and FIG. 4 to 6 show the chuck, FIG. 4 is a front view, and FIG. 5 is a front view of a part of the chuck element.
FIG. 6 is a sectional view taken along line A--A in FIG. 5. 1... shaft tube, 2... cap, 5... lead core, 12...
...Guide wall, 14...Storage tube, 19...Differential ring.

Claims (1)

[Scope of utility model registration request] an axially movable slider means which elastically holds the lead core by frictional action and whose tip is biased to protrude from the tip of the shaft cylinder; A storage cylinder is movably provided and biased forward, and a movement control means is provided in the storage cylinder to allow the lead core to move forward and prevent the lead core from moving backward, and when the slider means moves backward, the storage cylinder When the cylinder is retracted and the slider means moves forward, the storage cylinder moves forward and automatically feeds out the lead core, and a differential ring that expands elastically is fitted in the front part of the storage cylinder, The guide wall on which the differential ring in the backward position slides is formed to have a small diameter so that the storage tube moved rearward by the slider means starts later than the forward movement of the slider means, and is pressed against the guide wall to temporarily delay the forward movement of the storage cylinder, and the guide wall in front of it is formed to have a large diameter, and with the differential ring released from the pressure bond, the storage cylinder is moved to the forward movement position. A self-feeding mechanical pencil that is characterized by being designed to move.