JPH1111079A - Rotary type double core writing implement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary type double core writing implement being slender and suitable for the writing implement for a pocket notebook. SOLUTION: In a rotary type double core writing implement of which a holder tube 10 is made up of a front holder 12 and a rear holder 11 connected together rotatably and wherein a cylindrical cam 30 made of synthetic resin and fixed to the rear holder makes one of two ball-point pen refills 40 or one of the ball-point pen refill and a mechanical pencil core 50 move back, while making the other move forward to make a writing part project from the tip opening of the front holder so that writing can be conducted, when the rear holder is rotated normally or reversely to the front holder, the outside diameter of the holder tube is made 7 mmϕ or less and the cylindrical cam is molded of polyacetal resin.

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] Such a rotary two-core writing instrument is accommodated in a cylinder fixed to a front shaft in a state where a ballpoint pen refill and a mechanical pencil tool or two ballpoint pen refills are ejected toward the tail end side. 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. Then, the actuator connected to the ballpoint pen refill or mechanical pencil and projecting from the side of the cylinder is in contact with the cam profile of the cylindrical cam,
When the rear shaft is rotated forward and backward with respect to the front shaft, both actuators move along the cam profile of the cylindrical cam. Accordingly, while one of the ballpoint pen refill and the mechanical pencil is retracted, the other is advanced, and the writing portion projects from the front end opening of the front shaft to enable writing. In the case of a rotary pen with a ballpoint pen and a mechanical pencil, when the writing part of the mechanical pencil projects 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 barrel of this rotary two-core writing instrument thinner, the number of parts is large and the internal structure is relatively complicated. Need to be At this time, if the diameter of the ballpoint pen refill is too small, the amount of ink decreases and the writable distance decreases. In addition, since the mechanical components of the mechanical pencil have many components and the lead core needs to have a certain thickness, there is a limit in reducing the diameter.

Accordingly, the diameter of the synthetic resin cylinder for guiding the ballpoint pen refill and the synthetic resin cylindrical cam arranged to cover the cylinder must be reduced as much as possible. However, a large rotational torque is applied to the cylindrical cam, and the actuator connected to the ballpoint pen refill or mechanical pencil tool moves along the cam profile of the cylindrical cam. If the diameter is increased, deformation occurs during use, and the front shaft and the rear shaft do not rotate smoothly. For this reason, conventionally, it has not been performed to use a rotary type two-core writing instrument as a slim notebook writing instrument.

Accordingly, an object of the present invention is to provide a rotary two-core writing instrument which is slender and is suitable for a writing instrument for a notebook.

[0007]

In order to achieve the above object, the present invention provides a front shaft and a rear shaft in which a shaft cylinder is rotatably connected, and two springs which are repelled to a tail end side. The ballpoint pen refill or the ballpoint pen refill and the mechanical pencil tool are guided by a synthetic resin cylinder fixed to the front shaft, and when the rear shaft is rotated forward and reverse with respect to the front shaft, it is fixed to the rear shaft and covers the cylinder. A cylindrical cam made of synthetic resin retracts one of the two ballpoint pen refills or the ballpoint pen refill and the mechanical pencil, and advances the other to make the writing part protrude from the front end opening of the front shaft so that writing can be performed. In the two-core writing instrument, the outer diameter of the shaft cylinder is set to 7 mmφ or less, and the cylindrical cam is formed of polyacetal resin.

[0008]

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 the writing portions 41 and 51 at the distal ends, respectively, 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. A joint 14 is fixed to the tail end opening, and a cylinder 20 for guiding a ballpoint pen refill 40 and a mechanical pencil tool 50 is fixed to the joint 14. That is, the cylinder 20 is fixed to the front shaft 12 so as to protrude from the tail end opening of the front shaft 12.

As shown in FIGS. 2 and 3, a cylinder 20 injection-molded with a highly rigid synthetic resin, for example, a polyacetal resin, has two guide holes 21 and 21 therein.
Having. In addition, the side surface of the middle part of the cylinder 20 is cut out to form axial window holes 22, 22 that communicate with the respective guide holes 21. In addition, cylinder 20
A small-diameter portion 24 divided into two is formed on the tail end side, and an arc-shaped flange 25 is formed at an end of the small-diameter portion 24. A rotation stopper 23 for restricting the rotation angle of the rear shaft 11 with respect to the front shaft 12 is provided on the surface of the cylinder 20.

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. 2, the cylindrical cam 30 is formed 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.

The outer diameter of the portion of the cylindrical cam 30 where the cam profile 31 is formed is 5.5 mmφ, and the inner diameter is 4.
1 mmφ. Therefore, the thickness of the portion where the cam profile 31 to which a large rotating torque is applied is formed is 0.7 m.
m, which is designed to be extremely thin. The cylindrical cam 30 is formed by molding a polyacetal resin. Polyacetal resin has an ester bond in its molecular chain, and its main chain is thick and hard, so that it has excellent rigidity, impact resistance and creep strength.

As described above, the cylinder 20 is fixed to the front shaft 12 and the cylindrical cam 30 is fixed to the rear shaft 11. At the time of assembly, the cylinder 20 is inserted into the cylindrical cam 30 as shown in FIG. I do. During this insertion process, the small diameter portion 24 of the cylinder 20 is elastically deformed and reduced in diameter, and the cylindrical cam 3
The 0 annular projection 35 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 connected to be relatively movable and rotatable. 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.

In this way, by rotating the rear shaft 11 forward and backward with respect to the front shaft 12, the writing portions 41 and 51 can be alternatively protruded from the front end opening of the front shaft 12.
At this time, a large rotational torque is applied to the cylindrical cam 30 designed to be thin. However, since the cylindrical cam 30 is formed of a polyacetal resin having excellent rigidity, impact resistance and creep strength, the cylindrical cam 30 is not deformed even when used for a long time, and the rear shaft 11 is connected to the front shaft 12. It rotates smoothly.

[0018]

As described above, the present invention comprises a front shaft and a rear shaft that are rotatably connected to a shaft cylinder. When the rear shaft is rotated forward and backward with respect to the front shaft, two writing portions are provided. However, in a rotary two-core writing instrument that can protrude from the tip opening of the front shaft and can be written, the outer diameter of the shaft cylinder is 7 mmφ or less, and the cylindrical cam is formed of polyacetal resin, so it is slender and notebook. And a rotary type two-core writing implement suitable for writing implements.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram of an assembled state of a cylinder and a cylindrical cam.

FIG. 3 is a sectional view of a cylinder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Axle tube 11 Rear shaft 12 Front shaft 13 Front shaft opening 20 Cylinder 23 Rotation stopper 30 Cylindrical cam 40 Ballpoint pen refill 41 Writing point of ballpoint refill 50 Writing instrument of mechanical pencil 51 Writing instrument of mechanical pencil

Claims (1)

[Claims] 1. A ball-point pen comprises a front shaft and a rear shaft rotatably connected to each other, and two ball-point pen refills or a ball-point pen refill and a mechanical pencil penetrating toward the tail end are fixed to the front shaft. When the rear shaft is rotated forward and reverse with respect to the front shaft by the synthetic resin cylinder, the synthetic resin cylindrical cam fixed to the rear shaft and covering the cylinder forms the two ballpoint pen refills or the ballpoint pen refills. And a rotary two-core writing implement that allows the writing part to protrude from the tip opening of the front shaft and to be writable while retracting one of the mechanical pencil and the other, and the outer diameter of the shaft cylinder is 7 mmφ or less. And a rotary cam, wherein the cylindrical cam is formed of polyacetal resin.
Core writing implement.