JPH08164698A - Telescopic mechanical pencil - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to solve the problem of breaking the core of an expandable mechanical pencil whose shaft length is freely expandable and convenient to carry, when the expanded state is changed to the contracted state. [Structure] When extended, the cursive body holder and the eraser holder are retracted forward and the writing portion and the knock portion are projected, respectively.
It is an expandable mechanical pencil in which the eraser holder and cursive body holder retreat forward when retracted, so that the writing part and the knock part each immerse, and it is clamped to the step part of the forward inner hole of the cursive body holder. A core pipe that is fixed in a circular shape and extends rearward of the inner hole and has a closed rear end, and a connecting portion of the cursive body is detachably fixed to the tip of the core pipe. The built-in core that is configured and loosely inserted in the core pipe is not affected by the expansion and contraction of the shaft length, and the problem of interference between the rear end of the gripped core and the tip of the built-in core can be avoided and damage to the core can be prevented. To do.

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 mechanical pencil whose axial length can be expanded and contracted.

[0002]

2. Description of the Related Art The axial length of a writing instrument is required to be convenient when writing, but it is more convenient to keep the axial length short when not in use in consideration of convenience of carrying. Therefore, an extendable mechanical pencil whose axial length is extendable has been proposed by the same applicant in Japanese Utility Model Publication No. 4-32306.

[0003]

However, when the axial length is expanded or contracted, the core accommodating part is expanded or contracted accordingly. Therefore, when the rear end of the lead that is gripped by the writing mechanism chuck mechanism and protrudes into the lead receiving part and the tip of either of the built-in lead that is loosely inserted in the lead receiving part is changed from the extended state to the contracted state. There is a problem of interference and damage to the core. It has been found that the probability that the cores interfere with each other becomes extremely high when the inner diameter of the lead accommodating portion is small or when there is a large amount of built-in lead in the lead accommodating portion. SUMMARY OF THE INVENTION It is therefore an object of the present invention to improve the above-mentioned conventional problems and to provide a telescopic mechanical pencil which has a freely adjustable axial length and is convenient for carrying.

[0004]

The telescopic mechanical pencil of the present invention devised to achieve the above objects is an improvement of the above-mentioned drawbacks of Japanese Utility Model Publication No. 4-32306. First, a front shaft, a rear shaft that is movable in the axial direction with respect to the front shaft and rotatable in the circumferential direction, and a rear shaft that is housed inside the front shaft so as to be movable in the axial direction, and the rear end portion of the front shaft moves in the axial direction. As a result, it is fitted to the writing body that extends the core and the trailing end portion of the writing body that has the driven cam projection A, and is elastically urged backward by the spring and further movable in the axial direction with respect to the leading axis and in the circumferential direction. Has a writing body holder that is non-rotatably attached to the writing body holder, and has a driven cam protrusion B, is movable in the axial direction with respect to the rear shaft, and is elastically moved forward in the axial direction with respect to the writing body holder by a spring, and is circumferentially movable. Eraser holder that is not rotatable in the axial direction, an axial vertical groove portion, an oblique groove portion A that extends obliquely forward from the front end thereof, and a lateral groove portion A and a vertical groove portion that extends from the tip thereof in a direction substantially perpendicular to the axial direction. Axial groove B from the rear end to the diagonal rear and the axial direction from the tip And the driven cam projection of the writing body holder and the driven cam projection of the eraser holder are fitted in the cam guide groove to form a shaft for the writing body holder and the eraser holder. The cam cylinder is mounted so as to be movable in the direction of rotation and rotatable in the circumferential direction and movable in the axial direction with respect to the rear shaft, but is assembled so that the rotation is integrated and springed backward by a spring. With the driven cam protrusion A of the writing body holder and the driven cam protrusion B of the eraser holder positioned in the vertical groove portion of the guide groove of the cam barrel, the front and rear shafts are relatively movable back and forth. Both the brush tip and the knock part provided at the rear end of the eraser holder remain immersed in the shaft, and when the rear shaft retracts relative to the front shaft, it is driven by rotation of the rear shaft with respect to the front shaft. Cam projection A The follower cam projection B is guided by the slant groove portion A and the slant groove portion B, respectively, and positioned and locked in the lateral groove portion A and the lateral groove portion B, respectively. In the mechanical pencil, a core pipe is fixed to the step portion of the front inner hole of the writing body holder in a sandwiched manner, extends behind the inner hole, and has a closed rear end. The writing pipe connecting portion is detachably attached to the tip portion of the core pipe.

[0005]

In the illustrated embodiment, the rotation stop ring A is located slightly in front of the central portion of the inner surface of which the mouthpiece 1 is press-fitted and fixed to the front end.
2 is fixed and the retaining shaft 3 is fixed to the outer surface of the rear end, the front shaft 4 is fixed, and the clip receiving ring 5 and the crown 6 having the central opening are press-fitted to the inner surface of the rear end opening to attach the clip 7. 8 is sandwiched, a rotation stop ring B9 is fixed at a position slightly rearward from the center of the inner surface, and a decorative ring 10 is fixed at the front end edge of the inner surface so as to be rotatable in the circumferential direction with respect to the leading shaft 4 and also in the axial direction. A rear shaft 11 that is movably assembled, and a rear end portion of a connecting portion 14 that incorporates a chuck mechanism 12 in a tube 13 and is connected to the chuck mechanism 12 as shown in FIG. A step portion 16 is provided on the outer surface of the front end of 13 so that it can abut against the inner edge portion 15 of the opening of the mouthpiece 1.
It has the same mechanism as a general mechanical pencil mechanism in which the core is extended by the chuck mechanism 12 by axially shifting the rear end portion, and is housed inside the mouthpiece 1 and the front spindle 4 so as to be movable in the axial direction. The writing body 17 and the driven cam projection A19 on the outer surface of the rear end cylinder portion 18 are provided, and the step portion 18 of the front end inner hole is provided.
The core pipe 40 extending behind the inner hole of the writing body holder 22 by sandwiching the step portion 18a by the flange portion 40a that abuts on the rear end of the a and the fixing ring 41 press-fitted from the tip of the tip portion 40b is provided. The end is closed by a tail plug 42 and fixed to the writing body holder 22, and the tip portion 40b and the connecting portion 14 of the writing body 17 are detachably fitted, and the rotation stopping ring A2 is attached.
The coil spring A21 is attached to the front end of the base 1 and the inner surface step portion 20 of the base 1, and is elastically bulged backward by the coil spring A21. Impossible cursive holder 22 and driven cam protrusion B on the outer surface
23 and a collar 24 are provided, and an eraser stopper fitting 26 holding an eraser 25 is fitted to the rear end portion of the knock cover 27.
The front end cylinder 28 is axially movable in the rear end cylinder 18 of the cursive body holder 22 but non-rotatably inserted in the circumferential direction, and is inserted between the collar 24 and the clip receiving ring 5. The eraser holder 30 elastically bulged forward by the coil spring B29, and the longitudinal groove portion 31 in the axial direction and the tip of the oblique groove portion A32 and the oblique groove portion A32 extending obliquely forward from the front end of the longitudinal groove portion 31 in the axial direction as shown in FIG. Vertical groove A33 that bends vertically
And a slanted groove portion B34 extending diagonally rearward from the rear end of the vertical grooved portion 31.
And a lateral groove portion B that is bent vertically in the axial direction at the tip of the oblique groove portion B34.
A cam guide groove 36 composed of 35 and 35 is provided, and the driven cam projection A19 of the writing body holder 22 and the driven cam projection B23 of the eraser holder 30 are fitted into the cam guide groove 36 and assembled with the rotation stop ring B9 to form the rear shaft 11. The cam cylinder 38 rotates integrally but is movable in the axial direction and is elastically bulged backward by a coil spring C37 interposed between its front end and the rotation stop ring A2 in the front shaft 4. The driven cam projection A19 of the body holder 22 and the eraser holder 30
With the driven cam protrusion B23 of the writing cylinder 17 positioned in the vertical groove portion 31 of the cam guide groove 36 of the cam barrel 38, the writing tip portion of the writing body 17 and the top end portion of the knock cover 27 respectively correspond to the tip opening of the mouthpiece 1 and the crown 6. The driven cam projection A19 of the cam barrel 38 is shown in FIG. 3 in a state where the rear shaft 11 is moved forward with respect to the front shaft 4 to minimize the axial length as shown in FIG. When the dimension is set so that the driven cam protrusion B23 is located at the substantially central portion of the vertical groove portion 31 of the cam guide groove 36 and the rear end portion of the vertical groove portion 31, and when the rear shaft 11 is pulled rearward with respect to the front shaft 4. The driven cam projection A19 is relatively vertical groove portion 31.
Decorative ring 10 of the rear shaft 11 in the state of moving to the front end of the
The retaining ring 3 of the front shaft 4 abuts against each other to enter the retracted limit state, and the rear cam 11 is further rotated with respect to the front shaft 4 to advance the driven cam projection A19 along the oblique groove A32. With the driven cam projection B23 retracted along the oblique groove B34 and positioned in the lateral groove portions A33 and B35, respectively, the writing tip of the writing body 17 projects from the tip opening of the mouthpiece 1 and the top end of the knock cover 27. The portion is dimensioned and configured so as to project and lock from the crown 6 by a required amount.

[0006]

In FIG. 1, the axial length is extended and the writing tip portion and the knocking portion are projected, and writing is performed in this state. When the lead is extended, the knock cover 27 is pushed forward, and the knocking force is sequentially erased. The eraser holder 30, the cam cylinder 38,
The lead is delivered to the writing body holder 22 and the connecting portion 14 of the writing body 17, and the lead is drawn out. When carrying after finishing writing, by rotating the rear shaft 11 with respect to the front shaft 4, the driven cam projection A19 and the driven cam projection A19 located in the lateral groove portion A33 and the lateral groove portion B35 of the cam guide groove 36 of the cam barrel 38 are formed. Driven cam protrusion B23
Are respectively guided by the slant groove portion A32 and the slant groove portion B34 and are located at the front and rear ends of the vertical groove portion 31, first the writing portion and the knock portion are depressed, and then the rear shaft 11 is advanced with respect to the front shaft 4 to extend the axial length. In the shortest state, the driven cam projection A19 is again positioned at the substantially central portion of the vertical groove portion 31 as shown in FIG. Further, when replenishing the built-in core, the mouthpiece 1 is removed, and the writing body 17 is pulled out from the tip portion 40b of the core pipe 40.

[0007]

As described above, the present invention is not limited to the fact that the shaft length can be expanded and contracted, but since the knock portion and the brush tip are retracted into the shaft when the shaft length is shortened, they can be attached to a pocket or the like. At the same time, problems such as the wick being accidentally pushed out and the tip of the brush penetrating into a pocket or the like are eliminated. In addition, since the built-in core is loosely inserted in the closed core pipe at the rear end, there is no problem that the rear end of the core gripped by the chuck mechanism and the tip of the built-in core inside the core pipe come into contact with each other even if the axial length is expanded or contracted. Absent. Therefore, the concern that the core will be broken is eliminated.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a longitudinal sectional view in a state where the axial length is extended.

FIG. 2 is a vertical cross-sectional view in a state where the axial length is shortened.

FIG. 3 is a developed plan view of a cam barrel.

FIG. 4 is a semi-longitudinal sectional view of a cursive body.

[Explanation of symbols] 1 mouthpiece 2 rotation stop ring A 3 retaining ring 4 tip shaft 5 clip receiving ring 6 crown 7 clip 8 mounting ring part 9 rotation stop ring B 10 decorative ring 11 rear shaft 12 chuck mechanism 13 tube 14 connection Part 15 Opening inner edge part 16 Step part 17 Writing body 18 Rear end cylinder part 18a Step part 19 Follower cam projection A 20 Inner surface step part 21 Coil spring A 22 Writing object holder 23 Follower cam projection B 24 Collar 25 Eraser 26 Eraser stopper metal fitting 27 Knock Cover 28 Front end tubular portion 29 Coil spring B 30 Eraser holder 31 Vertical groove portion 32 Oblique groove portion A 33 Horizontal groove portion A 34 Oblique groove portion B 35 Horizontal groove portion B 36 Cam guide groove 37 Coil spring C 38 Cam tube 40 Core pipe 40a Flange portion 40b Tip portion 41 Sticking ring 42 Tail plug

Claims (1)

[Claims] 1. A front shaft, a rear shaft which is axially movable with respect to the front shaft and rotatable in a circumferential direction, and a rear shaft which is housed inside the front shaft so as to be movable in the axial direction and whose rear end is in the axial direction. To a writing body that extends the core by moving to a trailing end and a trailing end portion of the writing body that has a driven cam projection A, and is elastically bulged backward by a spring and further movable in the axial direction with respect to the leading shaft. It has a writing body holder that is not rotatable in the circumferential direction and a driven cam protrusion B that is movable in the axial direction with respect to the rear shaft and is elastically urged forward by a spring and is movable in the axial direction with respect to the writing body holder. Further, the eraser holder is mounted so as not to rotate in the circumferential direction, the longitudinal groove portion in the axial direction, the oblique groove portion A extending obliquely forward from the front end thereof, and the lateral groove portion A extending further in a direction substantially perpendicular to the axial direction from the tip thereof. And the slanted groove portion B that goes diagonally rearward from the rear end of the vertical grooved portion and its tip Has a cam guide groove consisting of a lateral groove portion B extending in a direction substantially perpendicular to the axial direction, and the driven cam projection of the writing body holder and the driven cam projection of the eraser holder are fitted into the cam guide groove, thereby writing body holder and eraser holder. In contrast, it is mounted so as to be movable in the axial direction and rotatable in the circumferential direction and movable in the axial direction with respect to the rear shaft, but it is assembled so that the rotation is integrated, and is springed backward by the spring. With the cam barrel, the front and rear shafts can be moved back and forth relatively with the driven cam protrusion A of the writing body holder and the driven cam protrusion B of the eraser holder positioned in the vertical groove of the guide groove of the cam barrel. With the brush tip of the cursive body and the knock part provided at the rear end of the eraser holder both kept retracted in the shaft, the rear shaft relative to the front shaft retracted relative to the front shaft. Driven cam by rotation Force A and the driven cam protrusion B is guided to a respective oblique groove A and the swash groove B in the lateral groove portion A
In the retractable mechanical pencil, the dimensions of which are set so that both the writing tip portion and the knocking portion project out of the axis in the state of being locked in the lateral groove portion B and the lateral groove portion B. A core pipe is provided that is fixed in a sandwiched manner, extends behind the inner hole, and has a closed rear end, and the writing pipe connection part is detachably attached to the tip of the core pipe. Stretchable mechanical pencil that is characterized by being worn.