JPS6326720B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for centering a slider by pressing the tip of the core against a paper surface or the like and knocking it with the core protruding from the core tube of the slider. This invention relates to a tip-notch type sharp pencil that is devised so that a constant centering length can always be obtained regardless of the centering length of the pencil.

If the centering length by notching the tip is 1 mm, if the tip is notched with the core protruding 0.5mm from the core tube, the protruding length of the core will be 1.5mm, then the centering length will be If it is too long, the lead will easily break when writing. Therefore, in such a tip-notching type sharp pencil, whether the initial lead protrusion length before the tip is notched is 0.5 mm or 0.2 mm, it does not matter at all; after the tip is notched, the centering length is always 1 mm. If this were done, the above-mentioned inconveniences would be eliminated, and the benefits would be enormous. As a solution to this problem, if the chucked lead is forced into the chuck, the surface of the chucked part of the lead will be scraped, resulting in a smaller diameter, and the shavings will fill the space between the teeth of the chuck. As a result, a so-called "core slipping" phenomenon occurs, making it impossible to exhibit a satisfactory centering function.

An object of the present invention is to provide a novel tip-knock type sharp pencil that does not cause damage when the lead is forced in, and that can always maintain a constant centering length regardless of the initial protruding length of the lead. However, the following is an explanation based on the embodiment shown in the drawings.

In this embodiment, the shaft tube 1 consists of four parts: a tip part 1A, a front part 1B, an intermediate part 1C, and a rear part 1D. Core tube 11 at the tip, core entrainment member 12 inside
The slider 10 having a slider 10 is mounted in the barrel tip 1A so as to be movable back and forth, and a slider elastic member 15 is stretched between the front protrusion 13 of the slider 10 and the stepped portion 5 of the barrel tip 1A. The forward stop position of the slider 10 is determined by the front end surface of the front projecting part 13 being pressed against the other step part 4 of the barrel tip part 1A, and the backward stop position is determined, for example, when the elastic member 15 is fully loaded. It is determined when it is fully compressed.

The chuck device 16 for clamping and releasing the core is
A chuck elastic member 20 is stretched between the chuck body 17 and the chuck actuating tube 19, and a rolling element 18 is interposed, and the chuck is installed in the shaft cylinder tip 1A and front part 1B so as to be freely movable back and forth. . Chuck operating tube 19
A tip notch elastic member 25 is stretched between the rear end surface 23 and the front end surface 7 of the barrel intermediate portion 1C, and the step 21 of the chuck actuating tube 19 is pressed against the step 6 of the barrel front portion 1B. Alternatively, the chuck device 16 can be activated by pressing the tip portion 22, which is made of an end plate or the like provided at the tip of the chuck actuating tube 19, onto the rear end of the stepped portion 5 of the barrel tip portion 1A or the step portion 1a within the barrel tip portion 1A. The forward stop position is determined. When the slider 10 and the chuck operating tube 19 are both in the forward stop position, the tip 22 of the chuck operating tube 19 and the slider 10
The distance between the rear locking portion 14, which is formed from a collar or the like provided at the rear of the rear locking portion 14, is a length l, but it is also possible to make contact with l equal to zero unless both are at the forward stop position. The intermediate portion 1C of the barrel has a dowel 2a protruding from the inner surface of the overhanging tubular portion 3 which is spaced appropriately from the inner surface of the front portion 1B of the barrel provided at the front end and is capable of deforming outward, and cooperates with the dowel 2a. The temporary locking means 2 constituted by the dowel 2b of the chuck actuating pipe 19 is used to temporarily lock the chuck device 16 in its retracted position when the tip is notched. The force is determined to be such that it cannot be released only by the return of the slider resilient member 25, but can be released by adding the return force of the slider resilient member 15 to this.

Shaft cylinder front part 1B, intermediate part 1C and rear part 1D
The core storage tube 26, which is attached so as to be movable back and forth inside the shaft, has a rear end notch resilient member 30 between the rear end 8 of the intermediate portion 1C of the shaft cylinder and the front end surface of the protrusion 29 formed on the core storage tube 26.
is stretched, and the rear end surface of the protrusion presses against the front end surface of the protrusion 9 on the rear portion 1D of the shaft cylinder, thereby determining its retreat stop position. Core storage pipe 26 and chuck operating pipe 1
9 for telescopic connection with chuck actuating tube 1.
9 and a dowel 27b of the core storage tube 26 which can be fitted into the inner hole surface 27a by sliding friction. The core storage tube 2 resists the force of the elastic member 25 for the rear end notch.
6, the sliding friction coupling means 27
are fitted so that the front end surface 28 of the core storage tube 26 comes into contact with and presses the rear end surface 24 of the chuck body 17, and the chuck body 17 is advanced against the chuck elastic member 20.
This allows the chuck to open and move forward with the chuck open, but in the state shown in FIG. 1 where the core storage tube 26 is at the backward stop position and the slider 10 is at the forward stop position. The facing distance between the front end surface 28 of the core storage tube 26 and the rear end surface 24 of the chuck body 17 is made larger than the sum of the backward movement length of the slider 10 and the expected maximum core protrusion length l'max.

To explain the operation when knocking the tip with such a configuration, in the state shown in FIG. 1 in which the core protrudes from the core tube 11 by a length l', the tip of the core is placed on the paper surface P as shown in FIG. When pressed, the slider 10 whose core is held by the lead-carrying member 12 and the chuck device 16 whose core is gripped by the chuck body 17 are a repellent member 15 for the slider and a repellent member for the tip notch, respectively. Compress 25,
When the slider moves backward while maintaining the lengths l and l' of FIG. 15 is almost fully compressed, and the slider 10 cannot move back any further. However, if the core is continued to be pressed against the paper surface P, the core storage tube 2
Since the facing distance between the front end surface 28 of the chuck body 28 and the rear end surface 24 of the chuck body is larger than the sum of the backward movement length of the slider 10 and the expected maximum core protrusion length l'max, the chuck device 16 is further The resilient member 25 for the knot can be compressed and retreated, resulting in the state shown in FIG. 3, that is, l' is zero and l is l-l'. In FIG. 3, there is still a gap between the rear end surface 24 of the chuck body 17 and the front end surface 28 of the core storage tube 26. Note that this operation occurs when the core holding force of the lead entraining member 12 of the slider 10 is stronger than the elastic repulsive force of the slider resilient member 15; If the repulsive force is weaker than the elastic force of We will have to retreat.

Next, when released from the paper surface P, the elastic members 15, 25
The return force causes both the slider 10 and the chuck device 16 to move forward to return to their original states. In the returning process, as described above, the temporary locking means 2 is not released only by the backward force of the resilient member 25, so as shown in FIG.
A and 2b engage with each other, and a state is created in which the locking portion 14 of the slider 10 and the distal end portion 22 of the chuck operating tube 19 come into contact with each other. At the same time as causing such a state, the temporary locking means 2
Since the locking state is released by the sum of the return forces 5 and 5, as described above, both the slider 10 and the chuck device 16 return to the original forward stop position shown in FIG. This state is shown in FIG. The core ends up being paid out by a length l.

As explained above, in the present invention, the slider 10 pushed by the slider resilient member 15 can move back and forth by a predetermined distance, whereas the chuck device 16 pushed by the tip notch resilient member 25 is moved forward and backward by a predetermined interval. Since the notch allows the slider 10 to retreat by a length corresponding to the sum of the moving distance and the length of the core protruding from the tip of the core tube 11 of the slider 10, what is the core protrusion length l' in Fig. 1? Regardless of the length, the core and the tip of the core tube 11 can be pulled in flush with each other, as shown in FIG. Furthermore, the chuck operating tube 19 and the slider 10 constituting the chuck device 16 are provided with a distal end portion 22 and a rear locking portion 14 that can be engaged with each other in a front-to-back positional relationship. Temporary locking means 2 is provided to temporarily lock the chuck device 16 when the slider 10 and the chuck device 16 return when released,
The temporary locking means 2 is released when the rear locking portion 14 of the slider 10 is released from the tip 2 of the chuck operating tube 19.
Since this is done by the sum of the return forces of both elastic members 15 and 25 due to collision with the elastic members 15 and 25, the process always goes through the state shown in Fig. 4 and is completed as shown in Fig. 5. Therefore, the initial core protrusion length l' is Regardless, it is extremely superior in that it reliably achieves centering of a length corresponding to the interval l, and eliminates excess or deficiency in centering.

[Brief explanation of the drawing]

FIGS. 1 to 5 are sectional views sequentially showing centering by the tip notch of the tip notch type mechanical pencil according to the present invention. 2...Temporary locking means, 10...Slider, 1
4...Rear locking portion, 15...Resilient member for slider, 16...Chuck device, 19...Chuck operating tube, 22... Tip portion, 25... Resilient member for tip notch.

Claims (1)

[Claims] 1 The slider 10 pushed by the elastic member 15 for the slider is movable back and forth by a predetermined interval, and the chuck device 1 pushed by the elastic member 25 for the tip notch.
6 is capable of retracting a length corresponding to the sum of the moving distance of the slider 10 and the protruding length of the core protruding from the tip of the core tube 11 of the slider 10 by means of a tip notch, and the chuck actuating tube 19 constituting the chuck device 16 is At the front end and the rear end of the slider 10, there are distal end portions 2 which can be engaged with each other in a front-to-back positional relationship.
2 and a rear locking portion 14, and a temporary locking means 2 for temporarily locking the chuck device 16 when the slider 10 and the chuck device 16 return when the core is released after being pushed in. Locking means 2
The tip lock type sharp pencil is characterized in that the release is performed by the sum of the return forces of both elastic members 15 and 25 caused by the rear locking part 14 of the slider 10 colliding with the tip part 22 of the chuck operating tube 19. .