JPS6344560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a type of device that allows the core to be fed out to a fixed length by pressing the core tube that can protrude from the hole at the tip of the barrel against a paper surface and then releasing it. , relates to a so-called tip-knock type sharpening pencil.

This type of sharpening pencil is disclosed in US Pat. No. 2,865,330. According to this, by pushing the core or tip protruding from the tip into the shaft cylinder, the collect chuck device can be temporarily locked in the retracted position, and when the above pushing is stopped and released, The clamped lead moves forward due to the tip and the resistor installed in the tip, after which the locking of the above-mentioned collect chuck device is released and the collect chuck device moves forward, thus holding the core a certain distance from the outlet end of the tip. It has a structure that can be rolled out. However, the means for locking this collection chuck device in the temporarily retracted position tends to be a relatively complicated structure.

SUMMARY OF THE INVENTION An object of the present invention is therefore to provide a tip-notch type sharpening pencil which has a simple structure, requires fewer parts, and has a function to prevent the lead from protruding too much.

The present invention will be explained below using an embodiment shown in the drawings.

In FIG. 1, the barrel 1 is integrated by screwing together a tip member 1a, a front barrel 1b, a connecting barrel 1c, and a rear barrel 1d.
The tapered tip member 1a has a hole 2 in its front end portion and communicates with a cavity having a substantially similar external shape, and the cavity has first, second and third stepped end surfaces 3, 4,
5, forming three cylindrical inner surfaces. Of these, an annular locking body 6 and an annular member 7 are fitted inside the second cylindrical inner surface, and the locking body 6 is fitted into the second cylindrical inner surface.
It is arranged between the stepped end surface 4 of the annular member 7 and the front end surface of the annular member 7 to prevent it from coming off. The annular member 7 has a stepped portion 8 for regulating the retreating position of the slider 10, which will be described later.
There is.

Slider 1 with core tube 9 protruding from hole 2
0 has an annular protrusion 11 formed on its outer circumferential surface, and its rear part is a rear cylinder part 12 into which a core-carrying member 13 is fitted. The rear end surface of the annular projection 11 and the annular member 7
A first compression spring 14 is interposed between the annular projection 1
1 against the first stepped end surface 3, the steady position of the slider 10 is determined. However, by pressing the tip of the core tube 9 against, for example, a paper surface, the slider 10 can be retreated from its normal position against the force of the first compression spring 14, and the length of the retreat is
l ₁ , the annular protrusion 11 connects to the annular member 7
The retracted position of the slider 10 is determined. By the way, during this backward movement, although the locking body 6 can be smoothly retreated, the locking body 6
Since the inner diameter of the slider 10 is smaller than the outer diameter of the annular protrusion 11 of the slider 10, it can be passed through even with a considerable pressing force.
By making the force _Fs for locking the slider 10 by the locking body 6 greater than the return force _F1 of the first compression spring 14, the slider 10 can be parked in its retracted position. However, as in the second embodiment shown in FIG. 5, the locking body 6 fits into the recess of the slider 10, and the inner diameter of the small diameter portion of the annular member 7 is made smaller than the normal outer diameter of the locking body 6. by doing
F _s may be generated.

The construction of a collect chuck device 15 for a sharp pencil that engages and releases lead A is known in the art. In the illustrated example, a chuck body 17 is formed with a concave rolling element seat 16 on the outer surface of a core holding portion that is about to expand in the radial direction with a split from the tip, and a tapered guide surface is provided on the outside of the chuck body 17. 18, and a second chuck actuating body 19 interposed between the chuck body 17 and the chuck actuating body 19.
With the force of the compression spring 21, the rolling element 20 housed in the concave rolling element receiving seat 16 is pressed against the tapered guide surface 18 so as to bite into it. The core holding force by the core entraining member 13 is
When F _g , the force F ₂ of the second compression spring 21 is preferably weaker than F _g so that the chuck body 17 can be pulled out without the core held by the core entraining member 13 slipping.

A protrusion 23 is provided on the outer circumferential surface of the chuck actuating body 19 having a front end surface 22 so as to fit with the third cylindrical inner circumferential surface of the tip member 1a to enable movement in the axial direction.
There is. This protrusion 23 is located at the end surface 3 of the front shaft cylinder 1b.
5 to prevent the core from sticking out too much, but I will discuss this in detail later. An annular stepped portion 24 is provided at the middle of the outer circumference of the chuck operating body 19.
and a small-diameter cylindrical portion 25 behind it, and a spring seat body 26 that is slidably fitted into the small-diameter cylindrical portion 25 is connected to the stepped portion 2.
It is locked at 4 and cannot proceed any further.

The core storage tube 27, which is guided by the inner surface of the connecting shaft cylinder 1c and is movable in the axial direction, has a terminal member 26 fixed to its tip, and a friction resistance tube 29 fixed to the tip of the terminal member 28. do. The front end portion of the friction resistance tube 29 is connected to the small diameter cylindrical portion 25 of the chuck actuating body 19.
are fitted with relatively strong sliding friction resistance and are slidably connected. The portion designated by numeral 30 shows an indentation that has been deformed to provide such resistance.

An annular projection 31 formed on the outer peripheral surface of the terminal member 28
A third compression spring 32 is interposed between the spring seat body 26 and the spring seat body 26, and the spring seat body 26 is placed on the front inner end surface of the front shaft cylinder 1b, and the annular protrusion 31 is placed on the front inside of the connecting shaft cylinder 1c. The steady position of the chuck actuating body 19 and the wick storage tube 27 is determined by pressing against the respective end faces. When the normal position of the chuck operating body 19 is determined, the normal position of the chuck body 17 is also determined. The terminal member 28 also has a protruding end surface 33 that can press against the receiving surface 34 of the chuck body 17.
There is.

When the slider 10, the chuck body 17, the chuck actuating body 19, and the core storage tube 27 each occupy their normal positions, the retraction distance l ₁ of the slider 10, the rear end surface of the rear cylinder portion 12 of the slider 10, and the front end surface 22 of the chuck actuating body 19 the opposing distance l ₂ between the protruding end surface 33 and the receiving surface 34, the distance _{l 4 between} the rear end surface of the small diameter cylindrical portion 25 of the chuck actuating body 19 and the opposing surface of the terminal member 28; The distance l ₅ between the protrusion 23 of the actuating body 19 and the front end surface 35 of the front shaft cylinder 1b is set such that l ₂ < l ₁ < l ₃ < ₄ , l ₅ < l ₃ < l ₄ . stipulate. _l2 is approximately 0.5 to 1.0 mm.

The locking force of the slider 10 by the locking body 6 has already been increased.
The relationship between F _s and the return force F ₁ of the first compression spring 14 is F ₁
<F _s , the core holding force by the core-carrying member 13
The relationship between F _g and the force F ₂ of the second compression spring 21 is F ₂ <F _g
I have already mentioned that. The relationship between the sliding frictional resistance F _f exhibited by the frictional resistance tube 29 and the small diameter cylindrical portion 25 of the chuck actuating body 19 and the force F ₃ of the third compression spring 32 is set as F ₂ <F _f <F ₃ . For example, F ₂ 6
g, F ₁ 10g, F _g 15g, F _s , F _f is 100g, F ₃ is 500
It is about g.

Next, the operating mode of the sharpening pencil with the above configuration will be described.

(i) Initial centering Initially, the lead A, which is stopped on the inner surface of the closed chuck body 17, falls freely to the lead-carrying member 13 of the slider 10 when the mouth of the chuck body 17 is opened. The core must be fed by overcoming the resistance of the member 13. To do this, just as in the case of a normal rear-end snap-type sharp pencil, the lock cap (not shown) fitted to the rear end of the lead storage tube 27 can be pushed and released with a fingertip. That is, the friction resistance tube 29, which is integral with the core storage tube 27, is connected to the chuck actuating body 19 with a relatively strong sliding friction resistance F _f , and the spring seat body 26 can freely slide on the small diameter cylindrical portion 25. When the core storage tube 27 is advanced against the third compression spring 32, the collection chuck device 15 is also advanced, and when the core storage tube 27 is advanced by _l2 , the front end surface 27 is moved forward.
Since this contacts the end surface of the rear shaft cylinder 12 of the slider 10, the chuck actuating body 19 is prevented from moving forward.
As the core storage tube 27 continues to move forward thereafter, the degree of overlap between the small diameter cylindrical portion 25 and the friction resistance tube 29 increases (l ₃ decreases), and finally the protruding end surface 33 of the terminal member 28
Press the receiving surface 34 of the chuck body 17 to compress the second compression spring 21 and move only the chuck body 17 forward. This forces the rolling elements 20 toward the expanded diameter side of the tapered guide surface 18, so that the opening of the chuck body 17 expands by its own expansion force.

Next, the pressing force of the lock cap is released and the restoring force of the third compression spring 32 returns to the initial state.
9 and the friction resistance tube 29 are connected with relatively strong friction resistance, the chuck is pushed back until the stepped portion 24 of the chuck actuating body 19 hits the spring seat 26 with the mouth of the chuck open, and then the protruding end surface 33 and the receiving surface 34 move away from each other, but the friction resistance tube 29 decelerates and retreats due to the relatively large sliding friction resistance exhibited by the small diameter cylindrical portion 25 and the friction resistance tube 29. As a result, the second The return of the compression spring 21, that is, the return of the chuck body 17 is also carried out slowly, and finally the core A is held in its grip. Therefore, when the core storage tube 27 moves forward, the core entraining member 13
The core A is sent over the resistance of the core storage pipe 27.
When retracting, the chuck body 17 is retracted with its mouth open, and finally the lead A is held in its mouth again, so that the desired centering can be achieved by repeating the above-mentioned knocking operation.

(ii) Centering using tip notch Core tube 9 and core A (first
(see figure), the first compression spring 14 is compressed by pressing the first compression spring 14 against the paper surface P, etc., and the length l 1 of the annular protrusion 11 of the slider 10 comes into contact with the step 8 of the annular member _7.
move back. In such a case, the collection chuck device 15 that clamps the core A through the core A also resists the third compression spring 32 and maintains the same relative positional relationship with the slider 10, that is, keeps l ₂ constant. Retreat while holding. Chuck operating body 1
9 and the friction resistance tube 29 become larger (see FIG. 2). Next, the core tube 9 is separated from the paper surface P. As described above, since the locking force by the locking body 6 is stronger than the return force of the first compression spring 14, the slider 10 remains in the retreated position. In contrast, the collection chuck device 15 moves forward due to the strong return force of the third compression spring 32. In other words, the collect chuck device 15 feeds the clamped lead A by overcoming the resistance of the lead carrying member 13. FIG. 3 shows that the collector chuck device 15 has been advanced by a length l ₂ , so that the core A projects from the outlet of the core tube 9 by a length l ₂ , and the front end face 22 of the chuck actuating body has been moved forward by a length l 2 of the rear barrel part 12 of the slider. This shows the state immediately after the collision with the end face.

The slider 10 that was hit by the front end surface 22 slips out of the locking body 6 and hits the first compression spring 1.
The annular protrusion ₁₁ abuts against the first step end surface 3 and stops. On the other hand, the collect chuck device 15 advances the remaining distance (l ₁ -l ₂ ) and stops when the spring seat body 26 comes into contact with the inner end surface of the front shaft cylinder 1b (see FIG. 4). In this way, a relative deviation occurs in the forward movement of the slider 10 and the collect chuck device 15, but for the reasons described below, they can return to their respective steady state positions while maintaining the above-mentioned centered state. be. That is, the core A held by the core entraining member 13 is compressed by the force of the first compression spring 14.
While trying to move forward by Satsusato l ₁ ,
The chuck actuating body 19 is braked by the above-mentioned sliding frictional resistance and moves slowly along (l ₁ −l ₂ ), while, as mentioned above, the core clamping force F _g exerted by the core entraining member 13 is Since the force F ₂ of the second compression spring 21 is stronger, the core entraining member 1 of the slider 10
The core A, which is held at 3 and advances smoothly, is the second
The chuck body 17 is pulled out so that the compression spring 21 of the chuck body 17 is compressed to advance the rolling element 20 toward the larger diameter side of the tapered guide surface 18, and the core clamping force by the chuck body 17 is weakened. In this way, the core entraining member 13
The core A held between the slider 10 moves completely together with the slider 10, and therefore, the centering length from the outlet of the core tube 9 is the same between FIG. 3 and FIG. 4, and is approximately equal to _l2 . .

(iii) Preventing excessive centering In actual use, as shown in FIG. 4, for example, the tip A may be pressed against the paper surface etc. that is already protruding from the core tube 9, and the tip notch may be repeated in order to make the core A protrude longer. be. However, if it protrudes too long from the tip of the core tube 9, there is a risk that the lead A will break during writing, so no matter how many times the tip is punched, the length of the protrusion will not cause the lead A to break during writing. It is desirable to have a mechanism to prevent the core A from protruding too much. In the sharpening pencil of the present invention, over-centering can be prevented in the following manner.

In FIG. 4, assume that the tip of lead A is pressed against the paper surface. The difference from the case in which the core A extends to the exit of the core tube 9 in FIG. ₁ is that in the case of FIG. In the case of Fig. 4, the retraction length of core A is (l ₁
+l ₂ ), and therefore the interval indicated by l ₅ ' in FIG. 2 is shortened by l ₂ . Furthermore, if the core A protrudes 2l ₂ from the outlet of the core tube 9, the retraction length of the core A in that case is (l ₁ +2l ₂ ), which is shown in Fig. 2.
It can be seen that the interval indicated by l ₅ ' is shortened by 2l, and as the protrusion length l ₂ increases in this way, the protrusion 23 comes into contact with the end surface 35 of the front shaft cylinder 1b.
Since l ₅ < l ₃ < l ₄ , the chuck operating body 1
9 or the rear end of the chuck body 17 does not prevent each retreat. The protrusion 23 is the end face 3
When the core A alone or the core A and the core tube 9 are pressed and pushed forward even after hitting the core 5, the chucking force by the chuck body 17 becomes stronger and stronger, so there is no possibility of the core slipping. You can feel strong resistance in your hands. Therefore, release the pressure there. No matter how many times I repeat the tip, I feel a strong resistance in my hand and release the pressure there. Therefore, the length by which the core A protrudes from the core tube 9 will not exceed a certain certain length.

As is clear from the above explanation, since the slider 10 is locked by the locking body 6 in the present invention, the structure is simpler and the number of parts used is reduced compared to the type of locking the collect chuck device described above. In addition, if the function of preventing the core from protruding too much is performed, for example, with the rear end surface of the chuck body 17 preventing the core from retreating, core powder may be generated due to the core A slipping in the chucking part, and the core powder may be removed. This method is extremely superior in that over-centering can be prevented without causing this problem, which used to be the case due to inhibiting the chucking effect.

[Brief explanation of drawings]

FIGS. 1 to 4 are cross-sectional views of the knurled sharpener pencil of the present invention in the order of operation. Further, FIG. 5 is a sectional view of a slider portion of another embodiment. 1... Shaft tube, 2... Hole, 6... Locking body, 9... Core tube, 1
0... Slider, 13... Core entrainment member, 14... First
compression spring, 17... chuck body, 19... chuck operating body, 21... second compression spring, 22... front end surface,
23... Protruding portion, 27... Core storage tube, 32... Third compression spring, 33... Projecting end surface, 34... Receiving surface, 35...
End face.

Claims (1)

[Claims] 1 Slider 1 that partially protrudes from the tip of shaft cylinder 1
0 into the barrel 1, the collection chuck device 15 holding the core is simultaneously retracted by the same length, and when the tip is released, the slider 10
In the sharp pencil, the slider 10 is temporarily locked in a retracted position, and after the collect chuck device 15 moves forward, the slider 10 moves forward to return the slider 10 and the collect chuck device 15 to their initial positions to feed out the lead. a locking body 6 that locks the slider 10 in the backward position; and a chuck actuator that is slidable within the shaft cylinder 1 and is normally opposed to the slider 10 at an interval shorter than the forward and backward distance of the slider 10. A protrusion 23 is formed on the outer surface of the chuck operating body 19 to limit the sliding distance of the chuck operating body 19 by coming into contact with an end surface 35 formed on the inner surface of the shaft cylinder 1. A sharpening pencil with a notched tip.