JPS6229270Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a sharp pencil using a ball chuck, and when a lead protection tube that can be inserted and stored inside the shaft is protruded from the tip of the shaft when writing,
At the same time, by automatically protruding the lead by a predetermined initial centering length from the tip of the lead protection tube, it can be used for writing immediately without any special centering operation. This is what I did.

The structure and function of a ball chuck as one of the core clamping mechanisms is conventionally known, and in response to a force that pushes the clamped core, the ball chuck acts to increase the core clamping force through a wedge action, but on the contrary, The core clamping force is easily weakened even with a relatively weak force for pulling out the core, making it possible to pull out the core. Therefore, by attaching a core detent member to the slider to which the core protection tube is fixed, and by combining this with a structure in which the slider is always repelled forward, when the slider that has been moved backward returns to its original position, the core will return to its original position. The core can be pulled out from the ball chuck by the core holding force provided by the stopper member (see Japanese Patent Application Laid-Open No. 122326/1983). However, with this method, although it is possible to make the core and the tip of the core protection tube flush with each other, it is not possible to make the core protrude from the tip of the core protection tube. There was the inconvenience of having to perform the centering operation again.

On the other hand, Japanese Patent Application Laid-Open No. 53-145734 discloses that when the tip of a sharp pencil is pressed, a slider with a core detent member installed inside and a chuck holding the lead move back together, but when the pressure is released, the slider By providing a delay mechanism that allows one of the front and chuck to move forward and return to its original position first, and the other to return to its original position later, a configuration is shown in which the lead can be fed out using the tip knob. In order to keep the lead protection tube fixed to the tip of the slider retracted into the barrel, the slider can be pushed in and locked, and to release the lock when writing, the slider must be moved forward by the chuck. There is a description of what you can do by pushing it out. Furthermore, a configuration is also disclosed in which a floating piece that exerts an expanding action on the tip of the chuck is disposed in a free state between the slider and the chuck to forcibly expand the chuck.

However, in the case where there is a floating piece between the push-lockable slider and the chuck, the following problems are expected, although there is no specific description in the above-mentioned publication. First, since the length of the core holding tube is relatively long, the amount of retraction it hides is quite large, and there is another floating piece behind the slider that has a large amount of retraction, so there is no waste. There was a tendency to encourage a long remaining core length. Another problem is that if the free moving piece is in a free state, it will make a rattling sound when you shake the pencil, and the function of bringing the free moving piece together when the expanded chuck returns to its original position is less reliable. I had a tendency to retract the lead that was drawn out.

The purpose of the present invention is to eliminate such drawbacks, and the configuration thereof will be explained below using the illustrated embodiments.

The shaft body 1 of the illustrated sharpening pencil consists of a joint tube 3 into which a tip 2 is fitted, and a shaft tube 4 into which the joint tube 3 is screwed onto the tip. As before, the slider 7, which has the lead protection tube 5 fixed to the front and the lead detent member 6 attached to the inside, is provided inside the tip 2 so as to be movable in the front and back direction, and is always elastically moved forward by the elastic member 11. By flicking, the overhanging portion 8 of the slider 7 is pressed against the inner end surface of the tip 2, thus bringing the slider 7 to its steady rest position. When the slider 7, which is in a steady stationary position, is pushed against the elastic member 11 until the core protection tube 5 is almost flush with the front end surface of the tip 2 (see Figure 5), or it protrudes slightly from the tip 2. When it is pushed in as far as it will go, it is locked by the locking means 9 which cannot be released from its locking state even with some vibration or the like. As such a locking means 9, an O-ring 9a having an inner hole through which the protruding portion 8 can pass even if somewhat forcefully is attached to the inner surface of the tip 2 by a member 10. However, it is also possible to provide it on the slider 7 side or to employ a locking means other than the O-ring.

The rear end of the elastic member 11 described above is supported by a chuck expansion ring 13 that is movable between the rear end surface of the member 10 and the front end surface of the inner protrusion 12 formed on the joint pipe 3, and the chuck expansion ring 13 is movable between the rear end surface of the member 10 and the front end surface of the inner protrusion 12 formed on the joint pipe 3. The rear end surface of the ring 13 is connected to the inner protrusion 12.
By pressing against the front end surface of the chuck expansion ring 1
The steady rest position of No. 3 is determined. The slider 7 described above smoothly moves back and forth inside the chuck expansion ring 13. An expanding protrusion 14 is provided on the rear end surface of the chuck expanding ring 13 . Ball chuck set 15 is
A chuck body 16 to which a self-expanding force is applied in advance to the split head, and a chuck operating body 1 having an inclined surface.
7 are pressed in opposite directions by a chuck spring 18, and a rolling element 19 is disposed between the inclined surfaces of the chuck body 16 and the chuck actuating body 17, thereby achieving tightening that overcomes the self-expanding force of the chuck body 16. It obtains force, that is, core clamping force. The rollers 19 may be rollers in addition to balls. An expansion protrusion 20 is provided on the front end surface of the head of the chuck body 16 to face and cooperate with the expansion protrusion 14 described above.

A protrusion 2 is provided approximately in the middle of the outer surface of the chuck operating body 17.
1, and the setting spring 22 disposed in front of the protrusion 21 presses the rear end surface of the protrusion 21 against the barrel stepped portion 4a, thereby setting the entire ball chuck set 15 including the chuck actuating body 17. Bring it to its steady rest position. To perform centering using the ball chuck set 15 described above, the chuck actuating body 17 is pressed and moved forward by a predetermined length while the ball chuck set 15 is held between the cores, and then the expanding protrusion 1 of the chuck expanding ring 13 is moved forward.
4 and the expanding protrusion 20 of the chuck body 16 cooperate to push the chuck body 16 forward to release the core. This can be done according to the side-knock method in which the knob is pressed in the axial direction or in the axial center direction. In this embodiment, for this reason, the shaft cylinder 4
A knob 25 is inserted into the elongated hole 24 drilled at the position of the gripping fingertip.
The shaft 26 of the chuck body 16 is inserted through the shaft 26 and fixed to a push pipe 27 disposed opposite to the rear end of the chuck body 16. On the other hand, a sliding push pipe 28 is provided which can freely slide on the chuck actuating body 17. A push spring 23 having a stronger spring force than the spring 22 constantly pushes the sliding push pipe 28 backward. Of course, the push spring 23 may be interposed between the knob shaft 26 and the rear end of the chuck actuating body 17. When the chuck actuating body 17 in a steady stationary position is moved forward against the setting spring 22, the front end surface of the protrusion 21 comes into contact with the rear end surface 3a of the joint pipe 3 and stops. The front end surface of 17 may be regulated by coming into contact with the rear end surface of the inward protrusion 12 of the joint pipe 3.

The important point of this invention is that the chuck operating body 17 is in a steady stationary position, and the core protection tube 5 fixed to the tip of the slider 7 is connected to the shaft body 1, as shown in FIG.
When the slider 7 is locked by the locking means 9 in the pushed-in position, the rear end surface of the slider 7 protrudes rearward from the rear end surface of the chuck expansion ring 13, and the chuck body 16, which is in a steady stationary position, is It is to face the front end surface with a distance A corresponding to a predetermined initial centering length.

The operation shown when the above configuration is adopted will be explained next. When the sharp pencil in the writable state shown in FIG. A pressing force is applied to 28 and the pressing spring 23. Then, the weak setting spring 22 is compressed and moves the chuck operating body 17 forward, and the protrusion 21 hits the rear end surface 3a of the joint pipe 3 and is prevented from moving forward.
Since the mutual positional relationship of the chuck body 16, chuck operating body 17, and push pipe 27 remains unchanged and maintains the initial core clamping force, if the lead is gripped by the chuck body 16, the centering will be equivalent to the forward movement length of the chuck operating body 17. In this process, the expanding protrusion 20 of the chuck body 16 is connected to the expanding protrusion 1 of the chuck expanding ring 13.
4, the chuck expansion ring 13 is moved forward against the force of the resilient member 11 (see FIG. 2).

If the knob 25 is continued to be pressed forward even after the chuck actuating body 17 is prevented from moving forward, the push spring 23 will be compressed and the push tube 27 will be pushed against the chuck body 16.
It hits the rear end surface, compresses the chuck spring 18, and the chuck body 16 continues to move forward. After the chuck expansion ring 13 comes into contact with the rear end surface of the member 10, the expansion protrusion 20 of the chuck body 16 rides on the expansion protrusion 14 of the chuck expansion ring 13, and the head of the chuck body 16 (See Figure 3). In this expanded state, the core end protruding from the core protection tube 5 is then pressed against the paper surface or the like. Then, the core slides on the six core detent members and becomes flush with the core protection tube 5.
In this state, the slider 7 moves back (see FIG. 4). When the tip of the core protection tube 5 is pushed in sufficiently until it is almost flush with the tip 2, the slider 7 is locked by the locking means 9 as described above.
Furthermore, when you release your finger from the knob 25, the chuck expansion ring 13, the ball chuck set 15 including the chuck actuating body 17, and the push tube 27 return to their normal resting positions, and the lead is clamped again ( (See Figure 5). This state is when the device is carried or not in use, but as mentioned above, there is a gap A corresponding to a predetermined initial centering length between the rear end surface of the slider 7 and the front end surface of the chuck body 16. be. Therefore, when writing with this pencil, when the knob 25 is moved forward, the chalk body 16
The front end surface of the slider 7 presses the rear end surface of the slider 7 to release the locking means 9, and the slider 7 returns to its steady rest position by the restoring force of the resilient member 11. At that time, the core is
The tip of the core protection tube 5 protrudes further from the tip of the shaft body 1 by a length equivalent to the distance A.

As described above, the present invention not only allows the core protection tube 5 to be stored in the shaft body 1 which is preferable for safety when carrying, but also automatically stores the core protection tube 5 from the protruding core protection tube 5 when it protrudes during writing. It is extremely superior in that the lead can be protruded by the initial centering length and can be used for writing immediately. Further, since the slider 7 disposed inside the chuck expanding ring 13 protrudes rearward from the rear end surface of the chuck expanding ring 13 when the chuck is locked by pushing, it can closely face the ball chuck set 15, thereby increasing the remaining core length. This is effective in reducing the length of time. Furthermore, since the chuck expansion ring 13 is urged backward by the elastic member 11,
When the expanded chuck body 16 returns to its original position, the chuck expansion ring 13 returns together with the chuck body 16, and there is no chance of retracting the lead that has been pushed out.

[Brief explanation of the drawing]

The figure is a sectional view showing one embodiment of the present invention,
1 to 5 sequentially show the process of changing from the writing state to the carrying state. 1... Shaft body, 4... Shaft cylinder, 5... Core protection tube, 6
... Core detent member, 7 ... Slider, 9 ...
Locking means, 11... Elastic member, 13... Chuck expansion ring, 15... Ball chuck set, 16...
...Chick type.

Claims (1)

[Scope of utility model registration request] A slider 7 with a core detent member 6 mounted inside the shaft body 1, a chuck expansion ring 13 movably disposed outside the slider 7, and the chuck expansion ring 1.
3, a ball chuck set 15 that allows the chuck body 16 to expand, and a slider 7
A locking means 9 is provided for locking the slider 7 at the position where the core protection tube 5 fixed to the tip of the shaft is pushed into the shaft body 1, and an elastic member 11 is provided between the slider 7 and the chuck expansion ring 13. The chuck expansion ring 13 and the ball chuck set 15 are set by pressing the ball chuck set 15 rearward with the setting spring 22.
is brought to a steady stationary position, and the rear end surface of the slider 7, which is pushed and locked, protrudes rearward from the rear end surface of the chuck expansion ring 13, and aligns with the front end surface of the chuck body 16, which is in the steady stationary position, at a predetermined initial center. Sharp pencils are made of facing paper with a distance A corresponding to the protrusion length.