JP2578084Y2 - mechanical pencil - Google Patents

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 in which a core is extended by shaking a barrel.

[0002]

2. Description of the Related Art Conventionally, there has been known a mechanical pencil in which a shaft cylinder is lightly shaken to draw out a lead by using an inertia force of a weight. In addition, a knock portion that is interlocked with the chuck is provided at the rear end of the barrel so that the lead is excessively extended and the lead is immersed. Further, an eraser is mounted in the knock portion. In this type, the chuck is axially shifted with a weak force so that the core is extended only by shaking, so the conventional one biases the knock part with a strong spring different from the chuck spring. When the eraser is used, the core is hardly extended, but there is a problem that the core is extended when a strong force is applied.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art.

[0004]

In order to achieve the above object, the mechanical pencil according to the present invention is provided with a lead case having a chuck fixed to the tip in a shaft cylinder such that the chuck can be moved in the axial direction. A chuck spring that rebounds with a weak force is attached, and a weight that can be fitted to the lead case between the leading end and the rear end of the lead case and that can be shifted by its own weight is arranged, and the chuck is shaken by shaking the barrel. A mechanical pencil that is designed so that the core moves out along the axis, and is arranged behind the barrel.
The provided knock cylinder is provided with a shaft portion at the front axis,
A step is formed at the front end of the shaft and in front of the step
A slightly thinner shaft portion is provided, and further on the shaft center side outside the shaft portion
A displaceable elastic piece is provided and substantially outside the front end of the elastic piece.
A protrusion is formed around the circumference, and an eraser
And a knocking part is provided that protrudes from the rear end of the barrel.
And the fine shaft of the knock cylinder is loosely fitted into the rear end hole of the lead case.
As well as the stepped portion is brought into abutment with the rear end of the lead case.
The knock cylinder can be moved axially in conjunction with the core case.
On the other hand, in the shaft cylinder, the inclined step
Part is provided, and when the rear end of the barrel is turned downward, the weight
It is inserted by its own weight inside the elastic piece of the knock cylinder,
Is displaced in the axial direction even if the
It can be stopped.

[0005]

FIG. 1 shows an embodiment of the present invention. First,
A tip pipe 7 through which a core can be inserted is fixed to the tip of the base 5, and a holding chuck 8 made of rubber or the like through which the core is appropriately frictionally engaged and inserted is fixed to the end of the inner hole. A screw portion (female screw) having a stepped portion 6 at the end is provided behind the inner hole of the base 5.

[0006] The shaft cylinder 1 has a screw portion (male screw) at the tip of the cylinder.
The shaft 2 is provided with a hole having a front section 4, and the hole communicates with the inner hole of the rear cylinder. A step 3 is provided at the tip of the inner hole, and an inclined step 19 is provided at the rear end of the inner hole to engage with a projection 22 of a knock cylinder 20 described later.

The chuck 12 is fitted with the head of the fastener 13 engaged with the hole of the shaft portion 2 of the shaft cylinder, and the core case 9 is inserted into the inner hole portion of the shaft cylinder 1 to form the core case. A rear end of the chuck 12 is fixed to a front end of the chuck 9. At this time, a chuck spring 14 is urged between the step 3 at the tip of the inner hole and the collar 10 provided at the substantially tip of the core case 9. Note that the chuck spring 14 resiliently pushes the chuck 12 rearward with an appropriate weak force. The lead case 9 is provided with the chuck 12
A cylindrical body provided with a core accommodating portion through which a core can be inserted. A flange portion 16 is formed at a rear end of the cylindrical body with a slit 17 at an appropriate position. A cushioning material 11 such as rubber is fixed to the outer periphery of the leading end of the lead case 9 in contact with the rear end of the collar portion 10, and a weight 15 is fitted further rearward by elastic deformation of the flange portion 16. The weight 15 can be axially shifted between the cushioning material 11 and the flange portion 16 by its own weight.

[0010] A knock cylinder 20 is provided behind the shaft cylinder 1 so as to be able to shift the shaft in conjunction with the core case 9. The knock cylinder 20 is provided with a shaft portion 23 at the front axis of the flange portion 26.
As a result, a step 25 is formed at the front end of the shaft 23.
Slightly shaft portion 24 of the minutia is provided substantially at the front end outer periphery of the elastic piece 21 is further displaceable elastic piece 21 is provided on the outside of the shaft portion 23 and 24 in an axial side in front of the stepped portion 25 with
Projection 22 is formed on, and in its inner hole portion cylindrical portion 27 at a rear portion of the flange portion 26 is provided, sandwiched eraser 31
At the same time, an eraser stopper 29 to which a cleaning rod 30 is fixed is fixed to the end. A knock cover 32 is detachably fixed to the outer periphery of the cylindrical portion 27.

[0009] The shaft portion 24 of the knock sleeve 20 is loosely fitted in the rear end hole of the lead case 9, formed on the resilient piece 21 of the knock sleeve
The protruded portion 22 contacts the inclined step portion 19 of the bore of the barrel 1, and a crown 28 is fixed to the rear end hole of the barrel 1, and the crown 28 is
Front end in the state where substantially in contact with the rear end of the flange portion 26 of the knock sleeve 20. In this state, when the rear end of the barrel 1 is turned downward, the weight 15 moves by its own weight, abuts against the flange 16 at the rear end of the core case 9 and the elastic piece 2 on which the protrusion 22 is located.
1 inside.

[0010]

First, in order to extend the lead, the weight 15 is moved forward by grasping the barrel 1 and swinging it forward in the axial direction.
The wick case 9 and the chuck 12 are advanced by the inertia force of, and the wick is drawn out. When returning the core that has excessively protruded from the end pipe 7, the knock cover 32 is advanced with respect to the barrel 1, and the step portion 25 of the knock cylinder 20 pushes the rear end of the core case 9 to advance the chuck 12 together with the core case. Do. At this time, since there is nothing to prevent the elastic piece 21 and the protrusion 22 from displacing inward, the protrusion 22 is moved toward the axial center by the inclined step portion 19.
Displacement enables axis transition. The strength of the chuck spring 14 and the rigidity of the elastic piece 21 are set such that the elastic piece 21 and the protrusion 22 return to the displacement in conjunction with the retraction of the lead case 9. When using the eraser 31, the knock cover 32 is removed and the rear end of the barrel 1 is turned downward.
The weight 15 has its own weight inside the elastic piece 21 where the protrusion 22 is located.
And the protrusion 22 is axially inserted into the inclined step portion 19.
Even when pressed, displacement in the axial direction is prevented, so that even when the eraser rubber 31 is pressed, the core is not extended.

[0011]

[Effect of the Invention] The structure and operation of the mechanical pencil of the present invention are as described above. The core can be extended only by shaking the writing instrument forward in the axial direction, and knocking is prevented when the eraser is used, so that the usability is extremely good. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a mechanical pencil according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view showing a state where an eraser is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft barrel 2 Shaft part 3 Step part 4 Front part 5 Base 6 Step part 7 Tip pipe 8 Holding chuck 9 Core case 10 Flange part 11 Buffer material 12 Chuck 13 Fastener 14 Chuck spring 15 Weight 16 Flange part 17 Swarri 18 Gap 19 Inclined step part 20 Knock cylinder 21 Elastic piece 22 Protrusion part 23 Shaft part 24 Shaft part 25 Step part 26 Collar part 27 Tube part 28 Crown 29 Eraser stopper 30 Cleaning stick 31 Eraser 32 Knock cover 33 Core 34 Built-in core

Claims (1)

(57) [Scope of request for utility model registration] 1. A wick case having a chuck fixed to a tip thereof is housed in a shaft cylinder so as to be axially movable, and a chuck spring for resiliently pushing the zipper backward is attached between the tip and the rear end of the wick case. In a mechanical pencil, a weight that can be axially shifted by its own weight by being fitted to the lead case is arranged, and the chuck is shifted by the shaking of the shaft to draw out the lead . The knock cylinder arranged at the rear is
A shaft is provided at the center of the shaft, and a step is formed at the front end of the shaft.
And a slightly thinner shaft is provided in front of the step.
And an elastic piece that can be displaced toward the axis outside the shaft
And a projection is formed on the outer periphery of the substantially front end of the elastic piece,
An eraser is attached to the rear of the knock cylinder, and the rear end of the shaft cylinder
A knocking part is provided that protrudes from the knock cylinder.
The shaft of the eye is loosely fitted into the rear end hole of the lead case and the step
The rear end of the lead case is almost in contact with the knock case.
The shaft can be shifted in conjunction with the case, while the
An inclined step is provided at a position facing the protrusion of the knock cylinder.
When the rear end of the barrel is turned downward, the weight
The projection is inserted into the elastic piece by its own weight,
Axial displacement is prevented even when pressed in the axial direction
A mechanical pencil characterized as follows.