JP4792654B2 - mechanical pencil - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mechanical pencil having a slide member that can be projected and retracted at the tip of a shaft tube.
[0002]
[Prior art]
As an example, there is a mechanical pencil in which a mechanical pencil unit is disposed in an outer shaft, and the mechanical pencil unit is pressed from behind to project the tip. A typical example is Japanese Utility Model Laid-Open No. 63-180283. The utility model registration claim of that publication states that “the inner shaft of the inner structure having a tip pipe on the outer shaft is stored with a spring provided between the inner shaft portion of the outer shaft, the middle shaft, and the stopper, An elastic part that adjusts the core pressure is provided at the rear end of the sleeve, a cam cylinder containing a pushing part of a knocking rod that abuts on the rear side of the central axis is inserted into the outer axis, and the cam cylinder is a fixed cylinder at the rear end of the outer axis. And a spring that abuts against and urges the lower end surface of the rotating cam to provide a double knock mechanical pencil. " In other words, it is a device in which the middle shaft (mechanical pencil unit) is moved back and forth through a cam mechanism called a debit cam, and the tip of the middle shaft is projected and retracted from the tip of the outer shaft.
[0003]
[Problems to be solved by the invention]
However, in the above prior art, in order to project the middle shaft from the tip of the outer shaft, the knock portion must be pressed at least by the same amount as the amount of projection of the middle shaft, and the middle shaft with respect to the outer shaft. The locking / releasing operation must also be performed. For this reason, the knock portion has to be pressed more than the protruding amount of the central shaft. As a result, not only is the pressing operation cumbersome, but in the retracted state of the center shaft, the knock portion protrudes considerably from the rear end of the outer shaft, which significantly deteriorates the appearance. It was.
[0004]
[Means for Solving the Problems]
The present invention relates to a mechanical pencil having a slide member retractable into the distal end of the barrel, with its rearward of the slide member arranged Tamabachi member, to bias the slide member forward by the Tamabachi member A locking means for maintaining the state in which the slide member is housed in the shaft cylinder is disposed inside the shaft cylinder, and a rubber-like elastic body to be locked to the locking means is fitted on the outer peripheral surface of the slide member; A chuck body for gripping and releasing the core is disposed in front of the shaft cylinder, the chuck body is brought into contact with the slide member, and the locking means is unlocked by the contact operation. This is the gist.
[0005]
[Action]
After unlocking, the slide member protrudes from the barrel by the force of the elastic member.
[0006]
【Example】
One example will be described with reference to FIG. A core tank 2 is disposed in the shaft cylinder 1 so as to be movable back and forth. A knock member that also serves as a lid of the core tank 2 is detachably attached to the rear end of the core tank 2. Of course, the knock member protrudes from the rear end of the shaft tube 1.
On the other hand, a chuck body 4 is fixed to the front end of the lead tank 2 via a joint 3. A chuck ring 5 for opening and closing the chuck body 4 is loosely inserted on the front outer periphery of the chuck body 4, and the chuck ring 5 is movable in the front-rear direction in the inner peripheral recess 7 of the intermediate member 6. positioned. Reference numeral 8 is a ring member fixed in front of the inner peripheral recess 7, and restricts the advance position of the chuck ring 5. That is, when the chuck ring 5 comes into contact with the ring member 8, the chuck body 4 is expanded and the gripped core is released.
The intermediate member 6 has a flange 9 at the rear part, and the flange 9 is a front end portion of the shaft tube 1 and a stepped portion of a tip member 10 screwed to the front end of the shaft tube 1. 11 is sandwiched between them. That is, the flange 9 is sandwiched and fixed in the shaft tube 1, whereby the intermediate member 6 itself is fixed to the shaft tube 1.
Reference numeral 12 denotes an elastic member such as a coil spring that urges the lead tank 2 and the chuck body 5 backward.
[0007]
In addition, a slide member 13 is disposed in front of the chuck body 4, and a cylindrical portion 13 a extends from the rear portion of the slide member 13, and the front portion of the relay member 6, And the middle part is covered. And the O-ring which consists of rubber-like elastic bodies is fitted by the rear outer peripheral surface of the cylindrical part 13a, and it latches on the protruding latching member 15 fixed to the front inner surface of the shaft cylinder 1. is doing. In this embodiment, the locking member 15 is actually fixed to the inner surface of the rear portion of the tip member 10.
On the other hand, a reduced diameter portion 16 is formed on the front inner side of the slide member 13, and a core detent member 17 made of a rubber-like elastic body that prevents the retraction of the core is press-fitted and fixed to the reduced diameter portion 16. However, it may be formed integrally with the slide member 13. The diameter of the reduced diameter portion 16 is slightly smaller than the outer diameter at the front end portion of the chuck body 4. That is, the front end surface of the chuck body 4 can come into contact with the reduced diameter portion 16. Further, an outer cone portion 18 is formed in the vicinity of the outer peripheral surface of the reduced diameter portion 16 so that it can come into contact with an inner cone portion 19 formed on the front inner surface of the tip member 10. Reference numeral 20 denotes a core protection tube made of a metal material fixed to the front end of the slide member 13, but may be formed integrally with the slide member. Reference numeral 21 denotes an elastic member such as a coil spring that urges the slide member 13 forward, but is set smaller than the locking force of the slide member 13 to the locking member 15 of the O-ring 14. .
The distance A until the chuck body 5 releases the lead is set to be shorter than the distance B at which the O-ring 14 is detached from the locking member 15. That is, after the chuck body 4 releases the lead, the front end of the chuck body 4 comes into contact with the reduced diameter portion 16 of the slide member 13, and then the O-ring 14 is detached from the locking member 15. Further, the protruding length D of the slide member 13 from the tip of the shaft cylinder 1 is based on a pressing operation distance (B + C (distance until the front end surface of the chuck body 4 contacts the reduced diameter portion 16) of the knock member). Is also set longer. Incidentally, in this example, the length is set to about twice.
[0008]
Next, the operation will be described. When a knock member (not shown) is pressed, the lead tank 2 and the chuck body 4 move forward. As the chuck body 4 advances, the core also advances and protrudes from the tip of the core protection tube 20, but when the chuck ring 5 comes into contact with the ring member 8, the chuck body 4 expands to release the gripped core. . Here, when the chuck body 4 further advances, the front end thereof comes into contact with the reduced diameter portion 16 of the slide member 13 to advance the slide member 13. As the slide member 13 advances, the O-ring 14 of the slide member 13 is detached from the locking member 15. At this time, the slide member 13 vigorously protrudes from the tip end of the shaft tube 1 by the elastic force of the elastic member 21 and the outer surface conical portion 18 of the slide member 13 fits into the inner surface conical portion 19 of the tip member 10. Abut. That is, depending on the length of the cylindrical portion 13a of the slide member 13, the slide member 13 moves forward and protrudes more than the pressing operation of the knock member. Specifically, in the slide member 13 of this example, the slide member 13 moves forward and protrudes about twice as long as the pressing operation distance. At this time, since the lead is lightly held by the lead detent member 17, the lead is also pulled out together with the slide member 13 .
Here, when the pressing operation of the knock member is released, the chuck body 4 is retracted by the elastic member 12 and is closed by the chuck ring 5 to grip the core again.
When the slide member 13 is stored in the shaft cylinder 1, the knock member is pressed again, the chuck body 4 is expanded, and the tip of the slide member 13 is lightly pressed on the desk or the like while maintaining the state. By this operation, the slide member 13 moves backward while resisting the elastic force of the elastic member 21, and the O-ring 14 of the slide member 13 is engaged with the engaging member 15 again.
[0009]
【The invention's effect】
The present invention relates to a mechanical pencil having a slide member retractable into the distal end of the barrel, with its rearward of the slide member arranged Tamabachi member, to bias the slide member forward by the Tamabachi member A locking means for maintaining the state in which the slide member is housed in the shaft cylinder is disposed inside the shaft cylinder, and a rubber-like elastic body to be locked to the locking means is fitted on the outer peripheral surface of the slide member; A chuck body for gripping and releasing the core is disposed in front of the shaft tube, the chuck body is brought into contact with the slide member, and the locking means is unlocked by the contact operation. Therefore, the projecting operation of the slide member is easy, and a mechanical pencil excellent in design can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal half sectional view (stored state) showing an example of the present invention.
FIG. 2 is a longitudinal half sectional view showing an operation (protruding state).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 core tank 3 Joint 4 Chuck body 5 Chuck ring 6 Intermediate member 7 Circumferential recessed part 8 Ring member 9 Grow part 10 Tip member 11 Step part 12 Repellent member 13 Slide member 13a Cylindrical part 14 O-ring 15 Locking Member 16 reduced diameter portion 17 core detent member 18 outer surface conical portion 19 inner surface conical portion 20 core protection tube 21 elastic member

Claims (2)

A mechanical pencil having a sliding member retractable into the distal end of the barrel, arranged Tamabachi member rearwardly of the slide member, thereby biasing said slide member forward by the Tamabachi member, the sliding member Locking means for maintaining the storage state in the shaft tube is disposed inside the shaft tube, and a rubber-like elastic body to be locked to the locking means is fitted on the outer peripheral surface of the slide member . A chuck body for holding and releasing the core is disposed in front, the chuck body is brought into contact with the slide member, and the locking means is unlocked by the contact operation. Mechanical pencil to do.   The mechanical pencil according to claim 1, wherein an outer surface conical portion is formed in an intermediate portion of the slide member, and an inner surface conical portion that contacts the outer surface conical portion is formed on a front inner surface of the shaft cylinder.

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