JP3318513B2 - Rotary 2-core writing instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary double-core writing instrument which is thin and is suitable for a writing instrument for a notebook.

[0002]

2. Description of the Related Art A ball-point pen refill and two ball-point pen refills having different colors of mechanical pencils and inks are accommodated in a barrel, and when a rear shaft is rotated forward and reverse with respect to a front shaft, one of the writing portions is obtained. However, many rotary type two-core writing implements that can be written by protruding from the front end opening of the front shaft have been put to practical use because one writing implement has the function of two writing implements.

[0003] In such a rotary type two-core writing instrument, a ball-point pen refill and a mechanical pencil pen or two ball-point pen refills are accommodated in a cylinder in a state where the ball-point pen refill is ejected to the tail end side. A joint made of a metal pipe is fixed, and a front shaft is detachably fitted to the joint. That is, the cylinder is fixed to the front shaft via the joint. A cylindrical cam having a front end edge inclined with respect to the axis and having a cam profile is fixed to the rear shaft to cover the cylinder. The actuator connected to the ballpoint pen refill or mechanical pencil and protruding from the side of the cylinder is in contact with the cam profile of the cylindrical cam. The child moves along the cam profile of the cylindrical cam. Therefore, while one of the ballpoint pen refill and the mechanical pencil is retracted, the other is advanced and the writing portion protrudes from the tip opening of the front shaft so that writing is possible. In the case of a rotary pen with a ballpoint pen and a mechanical pencil, when the writing part of the mechanical pencil is protruding from the front end opening of the front shaft, the rear shaft is pressed against the front shaft to perform a knocking operation. , The lead of the mechanical pencil is extended.

[0004]

The outer diameter of the shaft cylinder of such a rotary two-core writing instrument is usually 10 to 12 mmφ.
In order to make this rotary two-core writing instrument a notebook writing instrument, it is necessary to make the shaft cylinder thin, for example, 7 mmφ or less. In order to make the outer diameter of the shaft cylinder of this rotary two-core writing instrument thinner, it is necessary to reduce the diameter of each part because the number of parts is large and the internal structure is relatively complicated. Therefore, the joint connecting the front shaft and the cylinder also uses a small-diameter metal pipe.

[0005] When the ink of the ballpoint pen refill is consumed, the front shaft is pulled out of the joint to be separated and replaced with a new ballpoint pen refill. When the replacement is completed, the front shaft is fitted into the joint again. Therefore, the front shaft and the joint need to be connected with a fitting force that can be easily pulled out and have a fitting force that can transmit a rotational torque when rotating the rear shaft with respect to the front shaft. That is, it is necessary to design the fitting force to be within an appropriate range.

For this reason, conventionally, a plurality of axial ridges are formed on the surface of a joint made of a metal pipe, and when the front shaft is fitted to the joint, these ridges are pressed in the radial direction to form a metal pipe. Is elastically deformed, and this fitting force is obtained by the elastic force of the joint itself.

[0007] However, in order to use this rotary two-core writing instrument as a writing instrument for notebooks, as described above, a metal pipe having a small diameter is used as the joint. Hard to do. Therefore, the fitting force between the front shaft and the joint is inevitably increased, making attachment and detachment difficult. Further, if the height of the ridge is reduced to reduce the fitting force, the fitting force is weak, and when the rear shaft is rotated with respect to the front shaft, the rear shaft idles, so that there is a problem that the rotation torque cannot be transmitted.

Accordingly, an object of the present invention is to provide a rotary two-core writing instrument which is slender and can adjust the fitting force between the front shaft and the joint to an appropriate value and is suitable for a writing instrument for a notebook. And

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a shaft cylinder having a rotatably connected outer diameter of 7 mm.
A ball-point pen refill or a ball-point pen refill and a mechanical pencil penetrating to the tail end side, which consists of a front shaft and a rear shaft of less than mmφ, is guided by a cylinder, and the tip side of the cylinder is a metal pipe joint. , The front shaft is detachably fitted to the joint,
When the rear shaft is rotated forward and backward with respect to the front shaft, a cylindrical cam fixed to the rear shaft and covering the cylinder retreats one of the two ballpoint pen refills or the ballpoint pen refill and the mechanical pencil, and repositions the other. In the rotary type two-core writing instrument which is advanced to allow the writing portion to protrude from the front end opening of the front shaft and to be writable, in the portion where the front shaft of the joint is fitted, a plurality of axial ridges are formed, An axial slit is formed on both sides of the ridge.

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. The ballpoint pen and mechanical pencil-type rotary two-core writing instrument shown in FIG. 1 is a writing instrument for a notebook, is thinner than a normal writing instrument, and has a total length of about 130 mm and is designed to be short. In FIG. 1, a rear shaft 11 and a front shaft 12 are formed by a metal pipe.
And the outer diameter of the shaft cylinder 10 is 7 mmφ.
Hereinafter, for example, it is 6.5 mmφ. The rear shaft 11 is the front shaft 1
2 are connected so as to be able to rotate forward and backward within a predetermined angle range and to be able to move back and forth within a predetermined range. The ball-bar pen refill 40 having writing portions 41 and 51 at the tip and a mechanical pencil tool 50 are housed in the barrel 10. Note that two ballpoint pen refills 40 may be used in place of the mechanical pencil 50.

The front shaft 12 has a front end opening 13, and the tail end opening is fitted to a joint 60. And this joint 6
The tail end of 0 is fixed by caulking to the tip of the cylinder 20 that guides the ballpoint pen refill 40 and the mechanical pencil tool 50. That is, the cylinder 20 is fixed to the front shaft 12 via the joint 60. Joint 60
Is made of, for example, a stainless steel pipe having an outer diameter of 5.6 mmφ and a wall thickness of 0.2 mm. As shown in FIGS. And three axially extending ridges 61 having a height of 0.18 mm. Then, slits 62 are provided on both sides of the ridge 61.
Are formed.

As shown in FIGS. 4 and 5, the cylinder 20 has two guide holes 21 and 21 inside. Further, the side surfaces of the middle abdomen of the cylinder 20 are cut out, and the axial window holes 22, 22 communicating with the respective guide holes 21 are formed.
Are formed. On the tail end side of the cylinder 20, a small diameter portion 24 divided into two is formed.
An arcuate flange 25 is formed at the end of the fourth. Then, the rear shaft 1 with respect to the front shaft 12 is provided on the surface of the cylinder 20.
A rotation stopper 23 for restricting the rotation angle of 1 is protruded.

Connecting pins 42 and 52 are connected to the ball-point pen refill 40 and the tail end opening of the mechanical pencil tool 50, respectively.
The guide hole 21 is inserted through the guide hole 21. And the connecting pin 4
Actuators 43 and 53 are fixed to the tail ends of 2 and 52, and the activators 43 and 53 project radially from the window 22 of the cylinder 20. Also, the cylinder 20 and the actuators 43 and 53
Return springs 44 and 54 are interposed on the outer periphery of the connecting pins 42 and 52 between the
And the mechanical tool 50 are the return spring 4
4, 54, it is repelled in the tail end direction.

A cylindrical cam 30 is fixed in the rear shaft 11. As shown in FIG. 4, the cylindrical cam 30 is obtained by cutting a cylindrical body substantially obliquely and forming a front edge as a cam profile 31. An annular projection 35 is formed on the inner peripheral surface near the tail end of the cylindrical cam 30. Also, the tip 36
Are cut slightly so that the actuators 43 and 53 are locked when the writing portions 41 and 51 are in a protruding and writable state.

As described above, the cylinder 20 is connected to the front shaft 12 through the joint 60, and the cylindrical cam 30 is fixed to the rear shaft 11. However, during assembly, as shown in FIG. Insert the cylinder 20. During this insertion process, the small diameter portion 24 of the cylinder 20 is elastically deformed and reduced in diameter, and the annular projection 35 of the cylindrical cam 30 gets over the flange 25 of the cylinder 20. Therefore, the cylinder 20 and the cylindrical cam 30 are connected in such a manner that the annular projection 35 is movable within the range of the small diameter portion 24 and is rotatable. That is, the front shaft 12 and the rear shaft 11 are relatively movably and rotatably connected. At this time, the actuators 43 and 53 come into contact with the cam profile 31 of the cylindrical cam 30 by the elastic force of the return springs 44 and 54.

When the rear shaft 11 is rotated forward with respect to the front shaft 12, one of the actuators 43 and 53 advances along the cam profile 31, and the other retreats along the cam profile 31. A writing section 41 of the cylindrical cam 30;
One of the projections 51 protrudes from the distal end opening 13 and the distal end portion 36 of the cylindrical cam 30 is engaged with one of the operators 43 and 53 to enable writing. Next, when the rear shaft 11 is rotated in the reverse direction with respect to the front shaft 12, the writing portions 41 and 51 are both immersed in the front shaft 12,
When further rotated in the reverse direction, the other of the writing portions 41 and 51 protrudes from the distal end opening 13, and the distal end portion 36 of the cylindrical cam 30 is engaged with the other of the actuators 43 and 53 to enable writing.

Next, when the ink of the ballpoint pen refill 40 has been consumed, the front shaft 12 is pulled out with respect to the rear shaft 11. As a result, the front shaft 12 and the joint 60 are separated, and the ballpoint pen refill 40 is exposed. The ballpoint pen refill 40 is pulled out from the connection pin 42, and a new ballpoint pen refill 40 is inserted into the connection pin 42. Then, when the front shaft 12 is fitted to the joint 60, the refill replacement is completed. At this time, the joint 60 is a small-diameter pipe, and the pipe itself is not easily elastically deformed. However, since the slits 62 are formed on both sides of the ridge 61, when the front shaft 12 is attached to and detached from the joint 60, In addition, the protrusion 61 is easily elastically deformed in the radial direction. Therefore, the front shaft 12 and the joint 6
0 is easy to fit, and at the time of fitting, the ridge 61 presses against the inner peripheral surface of the front shaft 12 by this elastic force. And the torque can be transmitted reliably.

[0018]

As described above, the present invention comprises a front shaft and a rear shaft having an outer diameter of 7 mmφ or less, which are rotatably connected to a shaft cylinder, and when the rear shaft is rotated forward and reverse with respect to the front shaft. In a rotary type two-core writing instrument in which two writing parts are alternatively protruded from a front end opening of a front shaft and can be written, an axis is fitted to a portion where a front shaft of a joint connecting the front shaft and the cylinder is fitted. In addition to forming a plurality of ridges in the direction and forming slits in the axial direction on both sides of the ridge, the fitting force between the joint and the front shaft is adjusted appropriately even though the joint is a small diameter pipe. It is possible to provide a rotating double-core writing instrument which is thin and suitable for a writing instrument for a notebook.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a front view of a joint with a part cut away.

FIG. 3 is a cross-sectional view taken along line AA of FIG.

FIG. 4 is an explanatory view of an assembled state of a cylinder and a cylindrical cam.

FIG. 5 is a sectional view of a cylinder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Shaft cylinder 11 Rear shaft 12 Front shaft 13 Front shaft opening 20 Cylinder 23 Rotation stopper 30 Cylindrical cam 40 Ballpoint pen refill 41 Writing portion of ballpoint refill 50 Sharp pencil tool 51 Writing portion of sharp pencil tool 60 Joint 61 Ridge 62 slit

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-204997 (JP, A) JP-A-59-43194 (JP, U) JP-A-60-132377 (JP, U) 57690 (JP, U) JUN 4-25480 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B43K 21/00-21/26 B43K 24/00-24/18 B43K 27/00-27/12 F16B 7/00-7/22

Claims (1)

(57) [Claims] 1. An outer diameter of a shaft cylinder connected rotatably is 7 m.
A ball-point pen refill or a ball-point pen refill and a mechanical pencil penetrating to the tail end side, consisting of a front shaft and a rear shaft of mφ or less, are guided by a cylinder, and the front end of the cylinder is a metal pipe joint. , The front shaft is detachably fitted to the joint, and when the rear shaft is rotated forward and reverse with respect to the front shaft, the cylindrical cam fixed to the rear shaft and covering the cylinder is provided with the two ballpoint pen refills. Alternatively, in a rotary two-core writing instrument that allows writing by projecting a writing portion from a tip opening of a front shaft while retracting one of a ballpoint pen refill and a mechanical pencil, and moving the other forward, the front shaft of the joint is fitted. A plurality of axially extending ridges are formed in a portion to be joined, and axially extending slits are formed on both sides of the ridges. Expression 2-core writing instrument.