JP2000108580A - Writing implement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a writing implement which is so designed as to prevent cancellation of mutual connection of tubular bodies at the time of the operation of a writing medium letting-out mechanism. SOLUTION: An outer tube 10 is constituted of a plurality of tubular bodies 12, 14 and 16 connected with each other by screwing. A writing medium letting- out mechanism 20 is inserted into the outer tube 10 and an operating body 36 connected with the writing medium letting-out mechanism 20 so as to advance this mechanism is exposed outside the outer tube 10. A slit 16b extending axially by a prescribed length from the rear end of the rearmost tubular body 16 is formed in the rear end, while the operating body 36 has a clip 46 sliding through the slit 16b. A length L between the fore end of a sliding part 46b of the clip 46 and the fore end of the slit 16b is so set that a lead is let out at the time when the writing medium letting-out mechanism 20 is advanced by L in relation to the outer tube 10 and, on the other hand, that a load applied to the tubular body 12 from the writing medium letting-out mechanism 20 at the time of the advance is smaller than a load canceling the connection between the tubular bodies 12 and 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument, such as a mechanical pencil, a ballpoint pen, and a felt-tip pen, to which a writing medium such as a lead, an ink refill, and a felt lead is fed.

[0002]

2. Description of the Related Art Conventionally, commercially available writing instruments of this kind include:
An outer cylinder is composed of a plurality of cylindrical bodies joined to each other by screwing or press-fitting, and a writing medium delivery mechanism is inserted into the outer cylinder. The writing medium delivery mechanism is connected to the writing medium delivery mechanism to advance the writing medium delivery mechanism. It is known that the operated body is exposed from the outer cylinder. By operating the operating body, a writing medium delivery mechanism connected to the operating body sends out the writing medium, so that a writing medium such as a core, an ink refill, a felt core, and the like is sent out.

[0003]

For example, when a plurality of cylindrical bodies are screwed with screws, one of the cylindrical bodies connected to each other has a female screw, and one of the other cylindrical bodies has an internal thread. It will have an external thread. When molding a member having a female screw, a step of pulling out a core pin for forming the female screw from the inside of the cylindrical molded product at the end of the molding is required. At this time, it is certain that the core pin is pulled out while rotating along the screw, but it is time-consuming and the production efficiency is deteriorated. However, there is a possibility that the head of each thread of the female screw may be shaved during forcible removal, and the coupling force may be weakened after being screwed to a member having a male screw. Therefore, when the operating body is operated and the writing medium delivery mechanism moves forward, there is a problem that the coupling between the cylindrical bodies may be released due to the load applied to the tubular body from the writing medium delivery mechanism. . Such a problem is not limited to unreasonable situations, and may occur when the bonding force due to screwing is weak due to other factors, or when the press-fit is not reliably performed and the bonding force is weak.

[0004] The present invention has been made in view of such problems, and according to the first to third aspects of the present invention, the coupling between the cylindrical bodies constituting the outer cylinder is released when the writing medium delivery mechanism is operated. It is an object of the present invention to provide a writing instrument that does not have a problem.

[0005]

In order to achieve the above object, according to the present invention, an outer cylinder is constituted by a plurality of cylindrical bodies joined to each other by screwing or press-fitting. In the writing implement, a writing medium delivery mechanism is inserted, and an operating body connected to the writing medium delivery mechanism is exposed from the outer cylinder in order to advance the writing medium delivery mechanism.
While the writing medium delivery mechanism or the operating body and the outer cylinder allow the writing medium delivery mechanism to advance with respect to the outer cylinder necessary for sending out the writing medium, the writing medium delivery mechanism advances when the writing medium delivery mechanism advances. Forward movement restricting means is provided for inhibiting forward movement of the writing medium delivery mechanism with respect to the outer cylinder by a certain length or more so that a load applied to the cylindrical body from the mechanism is equal to or less than a load for releasing coupling between the plurality of cylindrical bodies. It is characterized by the following.

When the operating medium is operated to advance the writing medium delivery mechanism, the advancement restricting means allows the writing medium to be sent forward, so that the writing medium delivery mechanism sends the writing medium. Can be. On the other hand, if the writing medium feeding mechanism is to be advanced more than a certain length, the advance is prohibited by the advance restricting means. Therefore, the coupling between the cylindrical bodies is not released without applying an excessive load to the cylindrical bodies from the writing medium delivery mechanism during forward movement.

According to a second aspect of the present invention, in the first aspect, a slit extending a predetermined length in the axial direction from the rear end is formed at a rear end of the rearmost cylindrical body. The body has a clip which slides in the slit and extends in the axial direction to the outside of the outer cylinder, and the slit sliding portion of the clip and the slit constitute forward movement restricting means. According to a third aspect of the present invention, in the second aspect, the last tubular body is common to a plurality of types of writing medium delivery mechanisms for writing media. I do.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a first embodiment applied to a mechanical pencil as a writing instrument.
The outer cylinder 10 of the writing instrument is composed of a plurality of cylindrical bodies. In this embodiment, the tubular body is composed of the leading tool 12 and the leading shaft 1.
4 and a rear axle 16, which are screwed together. That is, a male screw 12 a is formed on the outer peripheral surface of the rear end of the leading tool 12, and a female screw 14 a screwed with the male screw 12 a is formed on the inner peripheral surface of the front end of the front shaft 14. A male screw 14b is provided on the outer peripheral surface of the rear end of the tip shaft 14.
And a female screw 16a screwed with the male screw 14b is formed on the inner peripheral surface of the distal end portion of the rear shaft 16. The tip 12 has a conical outer peripheral surface at the tip. A gripper 18 made of an elastic material for preventing slippage of a finger is mounted on the outer periphery of a part of the tip shaft 14 and the tip tool 12.

A writing medium delivery mechanism 20 is inserted into the outer cylinder 10 composed of the front tool 12, the front shaft 14, and the rear shaft 16. The writing medium delivery mechanism 20 includes:
A feeding chuck 22 for feeding a lead, which is a known medium for feeding a lead as a writing medium, a chuck ring 24 which is fitted over the head of the feeding chuck 22 and tightens the head of the feeding chuck 22, and a chuck ring 24 A chuck sleeve 26 abutting on the end, a lead tank 28 connected to the feed chuck 22, and a feed tank 22 inserted between the front end of the lead tank 28 and the front end of the chuck sleeve 26 via the lead tank 28. And a chuck spring 30 that constantly urges the rearward in the axial direction. The front end of the chuck sleeve 26 is in contact with a rear portion 12 b formed on the inner peripheral surface of the leading tool 12, and the rear end thereof is in contact with a step portion 14 c formed on the inner peripheral surface of the front shaft 14. It is fixed inside the cylinder 10. A plurality of openings 26a (only one is visible in the figure) are formed in the center of the chuck sleeve 26 to make the chuck sleeve 26 extendable and contractible in the axial direction. 12
In addition to absorbing the dimensional error between b and the step portion 14c, it also absorbs expansion and contraction when excessive writing pressure is applied, thereby preventing core breakage.

[0010] Further, a tip pipe 32 and a slider 34 connected to the tip pipe 32 are provided in the tip tool 12 so as to be movable in the axial direction. Writing medium delivery mechanism 2
The operating body 36 is connected to the rear end of the zero. Operation body 36
Has a receiving table 38 connected to the core tank 28 and a knock cover 42 detachably attached to the rear end of the receiving table 38, and projects rearward from the rear shaft 16 and is exposed. . The cradle 38 holds an eraser 40 and is integrated with a clip 46 extending in the axial direction to the outside of the outer cylinder 10. A base 46 a of the clip 46 has a slit 16 b formed at the rear end of the rear shaft 16. Is slidably fitted in The slit 16b extends a predetermined length from the rear end of the rear shaft 16.

The operation of the writing instrument configured as described above will be described. When the operating body 36 is knocked forward to feed the lead, the lead tank 28 connected to the operating body 36 moves forward, and at the same time, the feeding chuck 22 moves forward, feeds a predetermined amount of lead and moves the slider 34 forward. Extrude. Thus, the tip pipe 32 together with the slider 34
Moves forward, protruding beyond the tip of the leading tool 12, and can be written.

Here, the axial length of the sliding portion 46b that slides on the slit 16b of the base 46a of the clip 46 is slightly longer than the length required for the base 46a of the clip 46, and , Slider 34
The length L between the tip of the sliding portion 46b and the tip of the slit 16b when the core is retracted is equal to the length of the tip pipe 32.
In addition, from the state where the lead is retracted, the feeding chuck 22 moves forward and the tip pipe 32 is protruded from the tip of the tip 12 by a length necessary for projecting the tip pipe 32, in other words, the slider 34 is moved inside the tip 12. The length before contact with the front part 12c on the peripheral surface is about L1 or slightly shorter (small length in the illustrated example). To explain this point a little more, the writing medium delivery mechanism 20 includes the clip 4
6 can be advanced to the maximum by the length L at which the sliding portion 46b of the sixth abuts against the tip of the slit 16b. If the length L
However, assuming that the advance length of the feeding chuck 22 required for bringing the slider 34 into contact with the front stage portion 12c is considerably longer, the sliding portion 46b of the clip 46
If the clip 46 is to be advanced until it comes into contact with the front end of the front part 12b, the slider 34 comes into contact with the front part 12c and cannot move any further, so that the leading tool 12 is pushed forward. Therefore, if the connecting force between the leading tool 12 and the leading shaft 14 is weak, the binding between the leading tool 12 and the leading shaft 14 may be released. Therefore, in order to prevent such a release from occurring, the tip pipe 3 is set so that the load applied to the leading tool 12 is equal to or less than the load for releasing the connection between the leading tool 12 and the leading shaft 14.
2. With the slider 34 and the core retracted, the length L between the sliding portion 46b and the tip of the slit 16b is set to regulate the advance of the writing medium delivery mechanism 20. By setting the length L to about the length L1 or a length slightly smaller than the length L, when the feeding chuck 22 advances by L, the slider 34 only comes into contact with the front section 12c of the leading tool 12 or the front section 12c does not. In order to stop where it does not reach, little load is applied to the leading tool 12. However, it goes without saying that L is equal to or longer than the length required for the feeding chuck 22 to feed the core.
In this way, the sliding portion 46b of the clip 46 and the slit 16b of the rear shaft 16 constitute the forward movement restricting means.

In order to retract the core and the tip pipe 32, the operating body 36 is knocked again, and the core and the tip pipe 32 are moved into the tip 12 when the feeding chuck 22 releases the fastening to the core. Pressing is done conventionally. As described above, since an excessive load does not act on the tubular member 12, the front shaft 14, or the rear shaft 16 by the forward movement restricting means, it is not necessary to set these coupling forces so strong. Therefore, when forming the front shaft 14 and the rear shaft 16 on which the female screws 14a and 16a are formed, without forcibly pulling out the molded product while rotating the core pin, the thread of the female screws 14a and 16a is removed. Can be prevented from being released even if the force is slightly lowered and the bonding force when screwed is weakened.

FIG. 2 is a longitudinal sectional view showing a second embodiment applied to a ballpoint pen as a writing instrument. The outer cylinder 50 of the writing instrument includes a tubular tool 52, a front shaft 54 and a rear shaft 16, which are connected to each other by screwing. That is, a male screw 52a is formed on the outer peripheral surface of the rear end portion of the leading tool 52, and a female screw 54a screwed with the male screw 52a is formed on the inner peripheral surface of the distal end portion of the front shaft 54. A male screw 54 b is formed on the outer peripheral surface of the rear end of the front shaft 54, and a female screw 16 a screwed with the male screw 54 b is formed on the inner peripheral surface of the front end of the rear shaft 16. still,
Here, the rear shaft 16 is the same as the rear shaft of the first embodiment, and is a common component.

In the outer cylinder 50, a writing medium delivery mechanism 6 is provided.
0 is inserted. The writing medium delivery mechanism 60 is composed of a known mechanism that sends out an ink refill 62 as a writing medium, and a spring receiving portion 62a of the ink refill 62 and a leading tool 52 for urging the ink refill 62 rearward.
Return spring 6 inserted between the stepped portion 52b
4, a rotary cam 66 into which the rear end of the ink refill 62 is inserted and abutted, a knock cam 68 capable of pushing the rotary cam 66 forward, and a cam body integrally formed on the inner peripheral surface of the rear shaft 16. 70. Cam body 70
A cam portion having a saw-toothed tip and a groove portion are formed alternately in the circumferential direction on its inner peripheral surface, and a cam projection of the rotating cam 66 is engaged with the cam portion to advance the rotating cam. In this state, the cam projections 66 can be stored in the groove portions and retracted. The knocking cam 68 at the rear end of the writing medium delivery mechanism 60 has an operating body 7
2 are connected. The operating body 72 is integrated with a clip 74 extending in the axial direction outside the outer cylinder 50.
Is slidably fitted in a slit 16b formed in the rear end of the rear shaft 16.

The operation of the writing instrument configured as described above will be described. When the operating body 72 is knocked forward to send out the leading end of the ink refill 62 from the state where the leading end of the ink refill 62 is retracted in the leading tool 52, the knock cam 68 connected to the operating body 72 moves forward,
The rotating cam 66 is pushed forward of the cam body 70, and the rotating cam 66 is rotated by a predetermined angle so that the cam projection of the rotating cam 66 is engaged with the cam portion of the cam body 70 so as to be advanced. In this way, the ink refill 62 moves forward with the rotating cam 66, protrudes from the tip of the leading tool 52, and can write. When the operating body 72 is knocked forward again, the rotating cam 66 rotates by a predetermined angle, the cam projection is housed in the groove of the cam body 70, and the tip of the ink refill 62 retreats into the leading tool 52. I do.

Here, the axial length of the sliding portion 74b that slides on the slit 16b of the base 74a of the clip 74 is different from that of the sliding portion 74b when the tip of the ink refill 62 is retracted. The length L2 between the leading end of the slit 16b and the rotating cam 66 moves forward from the state where the leading end of the ink refill 62 is retracted and is pushed out to the front of the cam main body 70 to be free from the cam main body 70. The length is set to be about L3 or slightly longer (large length in the illustrated example).
If the length L2 is much larger than L3,
When the clip 74 moves forward until the sliding portion 74b of the clip 74 comes into contact with the tip of the slit 16b, the ink refill 62 moves forward together with the rotating cam 66 and pushes the leading tool 52 forward via the return spring 64. Will be. Since the return spring 64 is interposed, the load acting on the leading tool 52 is reduced. However, if the coupling force between the leading tool 52 and the leading shaft 54 is weak, the leading tool 52 and the leading shaft 54 will not be connected. May be uncoupled. Therefore, the tip of the ink refill 62 is retracted so that the load applied to the leading tool 52 is equal to or less than the load for releasing the connection between the leading tool 52 and the leading shaft 54 so that the release does not occur. The length L2 between the sliding portion 74b and the tip of the slit 16b is set to restrict the advance of the writing medium delivery mechanism 60. However, the length L2 needs to be equal to or longer than the length L3 necessary for the rotary cam 66 to reliably advance and rotate beyond the cam body 70. Thus,
The clip 74 and the slit 16b constitute a forward regulating means.

As described above, the same effects as those of the first embodiment can be obtained in the second embodiment. Further, since the rear shaft 16 of the first embodiment and the second embodiment is a common component, the same component can be used even if the writing medium is different, and the production efficiency can be improved. it can. It is not necessary to change the length of the slit 16b formed in the rear shaft 16 according to the writing medium. Generally, since the length L3 is longer than the length L1, the length of the sliding portions 46b, 74b of the bases 46a, 74a of the clips 46, 74 is changed for the same slit 16b. be able to. In addition to the rear shaft 16, the other front shafts 14, 5
4 and the leading tools 12, 52 can also be shared. Further, not only the connection between the front members 12, 52 and the front shafts 14, 54 but also the connection between the front shafts 14, 54 and the rear shaft 16 are not released.

In the above embodiment, the forward regulating means is provided between the operating body and the rear shaft. However, the present invention is not limited to this, and the forward regulating means may be provided between the writing medium delivery mechanism and the outer cylinder. Is also possible. Further, in the mechanical pencil according to the first embodiment, an example in which a movable tip pipe is provided has been described. However, the present invention is not limited thereto, and a mechanical pencil having a fixed tip pipe can be similarly applied. . Even in this case, it is preferable to provide the advance regulating means so that the load applied to the cylindrical body such as the leading tool by the advance of the feeding chuck of the writing medium feeding mechanism is equal to or less than the load for releasing the coupling between the cylindrical bodies.

[0020]

As described above, according to the first to third aspects of the present invention, advancement of the writing medium delivery mechanism by a predetermined length or more is prohibited by the advancement restricting means. It is possible to prevent a situation in which the medium is excessively advanced beyond the advance required for feeding the medium and a part of the cylindrical bodies is pressed to disconnect the cylindrical bodies. Therefore, it is not necessary to set the coupling force between the cylindrical bodies so much, and the work for coupling or the manufacturing work of the cylindrical bodies can be made more efficient.

According to the second aspect of the invention, by adjusting the length of the slit sliding portion of the clip, the allowable advance length of the writing medium feeding mechanism can be set. According to the third aspect of the present invention, the production efficiency can be improved by making the tubular body common to a plurality of types of writing medium delivery mechanisms for writing media.

[Brief description of the drawings]

FIG. 1 is a first example applied to a mechanical pencil as a writing instrument.
It is a longitudinal section showing an embodiment.

FIG. 2 is a longitudinal sectional view illustrating a second embodiment applied to a ballpoint pen as a writing instrument.

[Explanation of symbols]

 10, 50 Outer cylinder 12, 52 Tip (cylindrical body) 14, 54 Tip shaft (cylindrical body) 16 Rear shaft (cylindrical body) 20, 60 Writing medium delivery mechanism 36, 72 Operating body 46, 74 Clip 46b , 74b sliding part

Claims (3)

[Claims] An outer cylinder is composed of a plurality of cylindrical bodies connected to each other by screwing or press-fitting. A writing medium delivery mechanism is inserted into the outer cylinder, and writing is performed to advance the writing medium delivery mechanism. In a writing instrument, an operating body connected to the medium delivery mechanism is exposed from the outer cylinder, a writing medium delivery mechanism or a writing medium delivery mechanism necessary for delivering the writing medium between the operating body and the outer barrel. While allowing the advancement with respect to the outer cylinder, the writing medium delivery is performed such that the load applied to the cylindrical body from the writing medium delivery mechanism when the writing medium delivery mechanism advances is equal to or less than the load for releasing the coupling between the plurality of cylindrical bodies. A writing instrument, comprising: a forward movement restricting means for prohibiting forward movement of a mechanism relative to an outer cylinder by a certain length or more. 2. A slit extending from the rear end to the rear end of the cylindrical body by a predetermined length in the axial direction is formed, and the operating body slides through the slit and moves the shaft out of the outer cylinder. 2. The writing instrument according to claim 1, further comprising a clip extending in the direction, wherein the slit sliding portion of the clip and the slit constitute a forward movement restricting means. 3. The writing implement according to claim 2, wherein the last tubular body is common to a plurality of types of writing medium delivery mechanisms for writing media.