JPS6123438Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a notch-type sharp pencil, and when writing is started with the lead protruding a predetermined length from the tip of the cylindrical lead guide, the lead of this protruding length is consumed. It is an object of the present invention to provide an improved sharpening pencil in which the lead can further protrude from the tip of the lead guide without performing a lead feeding operation using a notch.

When performing normal writing using a sharp pencil, the length of the lead protruding from the tip of the lead guide is as follows:
The protrusion length is limited to a constant value due to the ease of breakage of the lead, and if this protrusion length becomes shorter due to wear during writing, the lead feed operation depending on the type of sharp pencil, such as the holding tube. It is necessary to click a button provided at the rear end of the lead to send out the lead by the desired length. However, since this lead feeding operation cannot be performed without interrupting the writing operation, it is often undesirable from the point of view of writing efficiency.

This invention provides a sharp pencil in which, if the lead feeding operation is performed at any time, the lead feeding operation is not required until the lead length equivalent to several times the protruding length of the lead is consumed. One embodiment of this will be described below with reference to the drawings.

In the figure, numeral 1 is a holding cylinder, and 2 is this holding cylinder 1.
This is a tip attached to the tip of the tip, and inside thereof, a cylindrical sliding hole 2a, a friction member sliding hole 2b, and a chuck ring sliding hole 2c, each having a different diameter, are formed. Reference numeral 3 indicates an inner cylinder coaxially inserted into the holding cylinder 1, 4 a lead chuck attached to the tip of the inner cylinder 3, and 5 a click button detachably attached to the rear end of the inner cylinder 3. 5
An eraser 6 is attached to the rear end of the eraser 6 if necessary. The leading end of the lead chuck 4 passes through the center hole of a chuck ring 7, and the rear end of the chuck ring 7 faces the front end of a sleeve 8 that is axially movable within the holding cylinder 1. This sleeve 8 is
A protrusion 1a provided on the holding cylinder 1 and protruding inward
a spring 9 whose rear end is engaged and supported by
is pushed toward the front end of its range of motion by
Further, the inner cylinder 3 is biased in the backward direction by a spring 10 provided between the inner cylinder 3 and the sleeve 8.

When no external force is applied, the sleeve 8 is held at the front end of its range of movement (the position shown in the drawing), while the lead chuck 4 fixed to the inner cylinder, which is biased in the backward direction, is held against the chuck ring 7. As the lead chuck 4 moves backward, the tip end of the lead chuck 4 tightens the core 11 passing through its center hole.
When the button 5 is pressed in this state, the inner cylinder 3 and the lead chuck 4 move forward together with the chuck ring 7 engaged with the tip thereof. After the chuck ring 7 reaches the position where it engages with the stepped portion 12 of the tip 2, the lead chuck 4 moves forward with respect to the chuck ring 7, and the tightening of the core 11 is released. Furthermore, when the lock button 5 is released, the inner cylinder 3 and lead chuck 4 move backward,
When the chuck ring 7 comes into contact with the sleeve 8 and the tip of the lead chuck 4 is tightened at this position, the inner cylinder 3 and the sleeve 8 stop. By repeating this operation, the cores 11 are sequentially fed out, and the length of the cores 11 fed out in one core feeding operation is approximately equal to the distance from the front end of the chuck ring 7 to the stepped portion 12.

Further, a cylindrical core guide 13 through which a core 11 passes through the tip 2 is fitted and supported so as to be movable in the axial direction, and a cylindrical body 14 and a friction member 15 are fixed to the rear end of the core guide 13. ing. The cylindrical body 14 is for regulating the front end of the movement range of the core guide 13 and for bringing the friction member 15 into accurate contact between the core 11 and the tip 2, and is provided with the cylindrical body sliding hole 2a of the tip 2. It has a cylindrical shape with approximately the same diameter, and is formed to be slidable in the axial direction within the cylindrical sliding hole 2a.

Furthermore, the friction member 15 provides appropriate frictional resistance against relative movement between the core guide 13, the core 11, and the tip 2, and as described above, the cylinder 14 has approximately the same diameter as the cylinder sliding hole 2a. Since the friction member 15 is formed in a cylindrical shape, there is no risk of tilted contact or rattling with the tip 2 and the core 11, and provides accurate frictional resistance to the rear end of the core guide 13 and a predetermined position. There is an interval of . Furthermore, as is clear from the figure, the inner circumferential portion of this friction member 15 is formed to have a larger diameter toward the rear end over a length longer than the amount of lead feeding by one notch for lead guidance. There is.

In the sharpening pencil configured in this way, in the process of advancing the lead 11 by the lead feeding operation described above, the frictional resistance between the lead 11 and the friction member 15 is greater than that between the friction member 15 and the tip 2. Since the core 11 is smaller than that in between, the core 11 advances relative to the core guide 13. Therefore, by protruding the lead 13 by an appropriate length from the tip of the lead guide 13, writing can be performed in the same manner as with a normal sharp pencil. While writing in this state, if the tip of the lead 11 becomes worn or broken and its protruding length becomes insufficient, perform an operation of pressing the tip of the lead 11 against the paper surface while holding the holding tube 1. . By this operation, the lead chuck 4 holding the lead 11
A pressing force in the backward direction acts on the inner cylinder 3 which is integral with the inner cylinder 3, and these members, together with the chuck ring 7 and the sleeve 8, move backward against the spring 9. Note that the movement range of these members in the backward direction is set to a value of about 0.5 to 1.0 mm. By the way, since the rear end of the spring 9 is engaged and supported by the protrusion 1a provided on the holding cylinder 1, the range of movement of these members in the rear end direction is at its maximum, and is at the maximum compressible position of the spring 9. It is possible up to
In this retraction process of the core 11, after the tip of the core 11 has retreated to the position of the tip of the core guide 13, a pressing force from the paper surface etc. will also act on the core guide 13, and the core guide 13 will be It retreats together with the cylindrical body 14 and the friction member 15. and core 11
When the core 11 and the core guide 13 have moved to the rear end of their movement range, the positions of the core 11 and the core guide 13 are aligned. Then, when the force pressing the holding cylinder 1 toward the paper surface is released, the restoring force of the spring 9 causes the sleeve 8 to
moves to the front end of its range of movement, whereby the chuck ring 7 moves forward together with the lead chuck 4 and the core 11 holding it and returns to its original position. However, the core guide 13
5 and the tip 2, the tip of the lead 11 does not advance due to the large frictional resistance between the lead 13 and the lead guide 13.
It protrudes from the tip of the core guide 13 by a length corresponding to the amount of retreat. And similar behavior is
This can be repeated until the core guide 13 reaches the rear end of its travel range.

If it becomes necessary to further protrude the lead 11 after the lead guide 13 has reached the rear end of its movement range, the knock button 5 is pressed to perform a normal lead feeding operation. In this operation, lead chuck 4
In the process of moving further forward after releasing the tightening of the core 11, the friction member 15 comes into contact with the rear end of the friction member 15, and advances this to the front end of the movement range. At this time, core 11
The core 11 moves forward by the same distance together with the friction member 13, so that the leading end of the lead 11 remains substantially aligned with the position of the leading end of the lead guide 13. Then, when the lock button 5 is released, the lead chuck 4 is moved to the lead 11.
Then, the core guide 13 is left in that position and is moved backward, stopping at the position where it engages with the chuck ring 7. If the button 5 is clicked again in this state, the lead 11 can be advanced by a predetermined length by the above-described operation. In this invention, as described above, the inner circumferential portion of the friction member 15 is formed to have a larger diameter successively toward the rear end over the amount of core feed by one knot, and the inclination of the inner circumferential portion is extremely gentle. Because of this, when the lead 11 attached to the lead chuck 4 is advanced by a knocking action or the like and penetrates the friction member 15, the tip of the lead 11 can be guided smoothly and reliably, and the lead 11 can be prevented from accidentally moving. It is possible to effectively prevent breakage of the core, interruption of the core feeding operation, unnecessary failure of the core feeding mechanism, etc.

In particular, the core 11 is often slightly bent due to manufacturing variations, and the sliding path in the axial direction of the lead chuck 4 is not always strictly the same. The above structure is extremely effective.

Furthermore, a predetermined gap 16 is provided between the core guide 13 and the friction member 15, so that the two do not come into direct contact. If the two are in contact, the gripping force of the friction member 15 on the core 11 will immediately change by 20 g to 30 g. Therefore, an operation that is performed through a subtle frictional force between the friction member 15 and the lead 11, for example, a tip knob that presses the tip of the lead guide 13 against the paper surface and keeps the lead 11 in a writable state for a long period of time. The operation of penetrating the friction member 15 with the core 11 described above is greatly affected, and there is a possibility that it will be difficult to perform it smoothly and reliably.

However, in this invention, as described above, the predetermined interval 16 is provided between the core guide 13 and the friction member 15, so that the above-mentioned operation can be performed smoothly and reliably.

As explained above, in the sharp pencil of this invention, when the lead guide 13 is in a position where it can be retracted, the tip of the lead 11 can be moved by simply pressing the tip of the lead 11 against the paper surface etc. without performing a knock operation. 1
1 can be made to protrude by the required length. This means that while the lead 11 is consumed by the length corresponding to the amount of movement of the lead guide, the lead feeding operation using the notch becomes unnecessary, and therefore, it is possible to write for a long time without changing the writing state. becomes possible. Further, when excessive pressure (writing pressure) is applied to the lead 11 during writing, the lead 11 elastically retreats, so that breakage of the lead 11 can be effectively prevented.

[Brief explanation of the drawing]

The drawing is a partially cutaway sectional view of a sharpening pencil according to an embodiment of the invention. 1... Holding tube, 1a... Protrusion, 2... Tip, 3
... Inner cylinder, 4 ... Lead chuck, 5 ... Knock button, 7 ... Chuck ring, 8 ... Sleeve, 11 ... Core, 13 ... Core guide, 14 ... Cylindrical body, 15 ... Friction member.

Claims (1)

[Scope of utility model registration request] An inner cylinder 3 housed movably in the axial direction in a holding cylinder 1 having a tip 2, a lead chuck 4 connected to this inner cylinder 3, a chuck ring 7 for tightening the tip of this lead chuck 4, and this chuck ring. The above-mentioned holding cylinder 1 is in contact with the rear end of 7.
A cylindrical sleeve 8 movable in the axial direction relative to the
a first spring 9 that urges the sleeve 8 in the forward direction; and a second spring that is attached between the sleeve 8 and the inner cylinder 3 and urges the inner cylinder 3 in the backward direction. 10, a core guide 13 having a center hole through which the core 11 passes, and is fitted into the tip 2 so as to be movable in the axial direction within a predetermined range; A cylindrical body that is fitted and fixed to the rear end, is formed into a cylindrical shape having approximately the same diameter as the cylindrical body sliding hole 2a inside the tip 2, and is slidable in the axial direction within the cylindrical body sliding hole 2a. 14 and the above core guide 1
3 and fixed to the cylindrical body 14 with a predetermined interval 16, and the cylindrical body sliding hole 2 of the tip 2 is fixed at the outer peripheral part.
With respect to the inner wall of the friction member sliding hole 2b having a larger diameter than a,
It slides into contact with a predetermined friction pressure without tilting or wobbling, and applies a predetermined friction pressure to the inserted core 11 on the inner surface, and over a length that is greater than the amount of core feed by one notch on the inner surface, The retracting distance of the friction member 15 and the sleeve 8, which are formed to have larger diameters in order toward the rear end side, is expanded to the maximum extent to the compressible limit position of the first spring 9, and the core 1
In order to make it possible to arbitrarily select the amount of protrusion of the first spring 9 depending on the usage condition, the first spring 9 is provided with a support member 1a that is provided at a predetermined position of the holding cylinder 1 and that engages and supports the rear end of the first spring 9. Sharp pencil.