JPH0368839B2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention provides a method for pressing the tip against the writing surface with writing pressure or a slightly stronger force while holding the main body in the writing position when the lead wears out during writing. Regarding a writing instrument that allows the lead to be fed out to a fixed length by releasing the pressing force, more specifically, when pressing force is applied to the lead, the lead retreats and the slider and chuck mechanism also move together through the lead. However, when the pressing force is released, that is, when the writing tip is pulled away from the paper surface and the slider and chuck mechanism are returned to their original positions, the return of the slider is delayed compared to the return of the chuck mechanism, and the slider's return is delayed. A continuous writing sharp that can be used in the drawing head of an automatic drafting machine, allowing the lead to be drawn out by the advancement of the chuck mechanism during temporary locking, and then allowing the slider to return while maintaining the protruding amount of the lead. It's about pencils.

<Background technology> The slider and the chuck mechanism are moved back a predetermined distance via the core, and both return to their original positions when the pressing force is released. At this time, the slider is temporarily locked in the retreated position. A sharpening pencil in which centering is performed by returning the chuck mechanism during that time and then returning the slider is generally called a tip-knock type, and is disclosed, for example, in Japanese Patent Application Laid-open No. 14099/1983 by the applicant of the present application. .
This structure employs an O-ring supported on the inner wall of the shaft cylinder as a temporary locking means for the slider, but there is room for improvement in the reliability and durability of its operation.

In addition to the above-mentioned structure in which the slider and the chuck mechanism have the same amount of retraction and centering is performed by relatively staggering the return times of both, there is a slider that is mounted on a cylindrical inner frame equipped with a chuck mechanism. The inner frame holds a ball that can move in the radial direction, and the outer peripheral surface of the slider, which is the ball abutting surface, is designed to move the slider back and forth with respect to the inner frame as the ball moves. JP-A-57-189898 discloses a structure in which a tapered portion is formed. However, this structure has the following drawbacks.

In other words, centering is performed by changing the amount of return of the middle frame and slider when the writing pressure is released, but it is extremely difficult to do this with a small amount of retraction, and the timing is difficult to do. If the writing is done incorrectly, there is a risk that it will not work, and since writing pressure must be applied to move the inner frame back a great deal, smooth centering cannot be achieved while writing.

<Disclosure of the Invention> The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional sharpening pencil, to reduce the play of related members until the centering operation, to enable centering while writing, and to improve the writing posture. To provide an improved sharp pencil capable of centering with writing pressure or a pressure slightly stronger than that without performing a special knocking operation while being held.

In short, the sharp pencil of the present invention slides in the axial direction with a slider having a chuck mechanism that prevents the lead from retreating and a lead-carrying member that holds the lead with a moderate frictional force biased forward. Between the chuck mechanism and the slider, there is provided means for temporarily locking the slider in its retracted position.
It has a rotor pressing member that rotates a rotor swingably supported on a shaft cylinder by retraction of the chuck mechanism, and a rolling element holder having a rolling element that moves in the axial direction by tilting of the rotor, On the outside of the rolling elements, a rolling element receiving member is provided which has an inclined guide surface that expands rearward.

<BEST MODE FOR CARRYING OUT THE INVENTION> The specific structure of the sharpening pencil according to the present invention will be described with reference to FIG. A rear shaft 1 which is operatively connected to a core tank 3 via a C ring 2 to a front cylinder part 1b having a tip 1a having a conical outer shape engaged with the front end.
c are screwed together to form the barrel 1 which becomes the pencil body. Inside the shaft cylinder, there are a slider 5 equipped with a core guide tube 4 protruding from the tip 1a, a rolling element 6 such as a ball that can press against the slider and hold the slider in the retreated position, a rolling element holder 7, etc. A slider locking means 8 consisting of a slider locking means 8, and a chuck mechanism 9 which allows the core to advance but prevents its retreat are arranged as follows.

First, the cylindrical slider 5 with the core guide tube 4 connected thereto is biased forward by a spring 10 whose rear end is fixed to the shaft tube 1, and is a core-carrying member that grips the core with a moderate frictional force. 11 and a rearward protrusion 5a so that it can come into pressure contact with a rolling element 6 of a slider locking means 8, which will be described later.

The rolling elements 6 are held in a plurality of holes equally spaced on the circumferential surface of the rolling element holder 7 so as to be freely movable in the radial direction. As shown in the figure, the rolling element holder 7 is provided outside the slider rear protrusion 5a, and the spring 1
2, it is urged forward. Rolling element holder 7
is adapted to be able to retreat against the spring 12 in accordance with the retreat of the chuck mechanism by a slider locking means 8 which will be described later.

A chuck mechanism 9 is provided behind the rolling element holder 7 that holds the rolling elements 6 so as to be movable in the axial direction. The structure of the chuck mechanism itself may be a ball chuck structure similar to the conventional one, and includes a chuck body 13 and a chuck operating body 14, which exhibit a wedge action due to the cooperation of the ball 17 and an inclined surface, and a rear end of the chuck body 13 and the chuck operating body 14. Under normal conditions, the opening of the chuck body 13 is closed by the spring 15 stretched between the two and the wedge action, thereby preventing the core from retreating. A friction resistance pusher 24 connected to the core tank 3 is fitted onto the rear of the chuck actuating body 14 with a moderate frictional force, and a rear end knob type is operated by the operation of the lock cap 30 integrally connected to the core tank 3. It is now possible to perform centering.

On the outside of the chuck operating body 14, there is a rotor pressing member 19 that is movable in the axial direction and has a shoulder portion 19a that can engage with the protrusion 18 of the chuck operating body so that it moves back together with the chuck operating body when the chuck operating body retreats. It is provided. This rotor pressing member 19 constitutes the slider locking means 8 in cooperation with a rotor 20 which is pivotally supported by the shaft cylinder 1 and whose inner end is engaged with the rolling element holder 7. The rotor pressing member 19 is urged forward by a spring 21 and comes into contact with the stepped portion 23 of the front shaft 1b, and its front end normally pushes the outer end of the rotor 20 forward to tilt it. In this way, the rolling element holder 7 is moved backward against the spring 12. In this state, the rolling element holder 7 retreats, so that the rolling element 6 is located at the rearward widening portion of the inclined guide surface 22a of the rolling element receiving member 22 provided on the inner surface of the tip 1a.

Next, the operation of the sharpening pencil according to the present invention will be explained with reference to FIGS. 1 to 4.

FIG. 1 shows a state in which the lead A protrudes from the lead guide tube 4 and is ready for writing. In this state, the spring 21
Since the rotor pressing member 19, which is biased forward at The body 7 has moved rearward, and the rolling elements 6 have retreated along the inclined guide surface 22a of the rolling element receiving member 22 to its widened portion. In this state, the wedge action by the rolling elements 6 does not move.

When the lead protruding from the lead guide tube becomes worn due to writing, the chuck mechanism, that is, the chuck body 13 and the chuck operating body, can be removed by applying the lead to the paper surface P and applying writing pressure or a slightly larger force as shown in Fig. 2. 14 retreat together as a unit due to the wedge action of the ball 17, and at the same time, the rotor pressing member 19, which had been urged forward until then, is dragged backward against the spring 21, and the rotor 20 is pushed back by the pressing member 19. It is released from the pressing force and becomes free, and spring 1
2, the rolling element holder 7 moves forward, and the rolling element 6 is moved to the inclined guide surface 22a of the rolling element receiving member 22.
As a result, the slider 5 is pushed into the reduced diameter portion of the slider 5, and a wedge action is exerted on the slider 5. The slider 5 is thus locked in its retracted position as shown in FIG. In order to cause such a slider locking action, the force F1 of the spring 10 that urges the slider 5 forward and the core gripping force of the core entraining member 11 attached to the slider 5 are used.
Due to the wedge action of Fg and the rolling elements 6, the slider 5
The relationship between the force Fs that locks the
<Fs. 11 in FIG. 2 indicates the retreat distance of the rotor pressing member 19.

FIG. 3 shows the state immediately after the core is separated from the surface of the paper and the pressing force applied to the core is released. In this figure, the chuck mechanism 9 is in the middle of returning, and the rotor pressing member 19, which is biased forward by the spring 21, moves forward and pushes the outer end of the rotor 20. The slider 5 moves backward until the wedge action of the rolling element 6 is released.
remains stopped in the reverse position. Therefore, the retreating distance of the rotor pressing member 19 is set to l1 (FIG. 2), and this pressing member 19 moves forward to push the rolling elements 6
If the position where the wedge action is released and the slider 5 is allowed to move forward and the distance from which the pressing member 19 moves further until it comes into contact with the stepped portion 23 of the shaft cylinder after the wedge action is released is 12, then The difference between l1 and l2 is the actual centering amount.

As described above, when the rotor pressing member 19 moves forward, the rotor 20 tilts and moves the rolling element holder 7 rearward. Since the slider 5 retreats to the expanded portion of the guide surface 22a, the lock of the slider 5 is released. The slider 5 whose wedge action has been released is the third
Spring 10 while maintaining the amount of core protrusion achieved in the figure.
Due to the action of , it moves forward and comes into contact with the locking surface in the tip 1a and stops, resulting in the state shown in FIG. 4. In this case, the chuck body 13 prevents the core from retreating but allows the core to move forward, as described above. Therefore, when transitioning from the state shown in FIG. 3 to FIG. The lead gripping force allows the lead to move forward together with the lead while maintaining its protruding length.

In the above, when the lead already protruding from the lead guide tube 4 is worn out due to writing, centering can be performed by pressing the lead against the paper surface while maintaining the writing posture, applying a pressing force to the lead, and releasing the pressing force. This is the operation when performing. The initial centering operation and other normal centering operations for notching the rear end are similar to those disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 14099/1982, and will be briefly explained below.

First, when the mouth of the chuck body 13 is opened, the lead supplied from the lead tank 3, which is stopped on the inner surface of the closed chuck body 13, is transferred to the lead-carrying member 11 of the slider 5.
After that, the core must be fed by overcoming the abrasion resistance of the core-carrying member 11. To do this, just like a normal rear-end snap-type sharp pencil, push and release the lock cap 30 fitted to the rear end of the lead tank 3 with your fingertips. That is, the friction resistance pusher 24 integrated with the core tank 3 is connected to the chuck actuating body 14 with relatively strong sliding friction resistance, and the chuck actuating body 14 is connected to the rotor pressing member 19 on the outside thereof.
Therefore, when the core tank 3 is moved forward against the spring 25, the chuck mechanism 9 also moves forward, and its front end comes into contact with the protrusion 26 of the rotor pressing member, preventing it from moving further. is prevented. When the core tank 3 is further advanced thereafter, the leading end surface of the core tank presses the rear end surface of the chuck body 13 and compresses the spring 15 tensioned on the chuck mechanism, thereby moving only the chuck forward. As a result, the ball 17 of the chuck mechanism 9 is driven to the widening portion of the tapered guide surface of the chuck operating body 14, and the mouth of the chuck body 13 is expanded by its own expanding force.

Next, the pressing force applied to the chuck cap 30 is released and the restoring force of the compression spring 25 returns it to its original state, but since the chuck actuating body 14 is connected to the frictional resistance pusher 24 by frictional resistance. While keeping the mouth of the chuck body 13 open, press the chuck operating body 14.
The protrusion 18 of the rotor press member 19 is pushed back until it hits the shoulder 19a of the rotor pressing member 19, and the friction resistance pusher 24 decelerates and retreats while receiving sliding friction resistance.As a result, the spring 15 in the chuck mechanism returns, that is, the chuck body returns. The core is slowly squeezed, and when it returns, the core is held tightly again. In this way, as the lead tank 3 moves forward, the lead A is moved forward by overcoming the resistance of the lead carrying member 11 of the slider 5, and when the lead tank moves back, it moves back with the mouth of the chuck body 13 open, and when the lead tank 3 is moved back, the lead A is moved forward. Since the core A will be clamped again at the point where the center ends, the desired centering can be achieved by repeatedly operating the knob cap 30.

Since the sharp pencil of the present invention has the above-described structure, it is possible to perform centering operations extremely smoothly by simply applying writing pressure or a force slightly larger than that, and the slider can be reliably temporarily locked for centering. It can be used not only as a normal mechanical pencil but also as a drawing head for an automatic drawing machine.

[Brief explanation of drawings]

Figures 1 to 4 are longitudinal cross-sectional views of a sharpening pencil according to an embodiment of the present invention, with Figure 1 showing the state before writing, and Figure 2 showing the state in which the lead is placed on the paper and pressure is applied. Figure 3 shows the state in which the chuck mechanism is in the process of returning immediately after the core has been released from the paper surface, and Figure 4 shows the state in which the slider has also returned after the chuck mechanism has returned and centering has been performed. It is a diagram. 4... Core guide tube, 5... Slider, 6... Rolling element,
7... Rolling element holder, 8... Slider locking means, 9
...Chuck mechanism, 11... Core entraining member, 13... Chuck body, 14... Chuck operating body, 19... Rotor pressing member, 20... Rotor, 22... Rolling element receiving member, 2
2a... Inclined guide surface.

Claims (1)

[Scope of Claims] 1. A slider equipped with a core guide tube and a core-carrying member that can protrude from the tip of the barrel can be freely pushed into the barrel and is elastically biased forward to prevent the core from retreating. The ball chuck mechanism, which is movable in the direction, is capable of retracting, and the slider is locked in its retracted position by having a locking means that exerts a locking force stronger than the return force of the slider that is elastically biased forward. In the sharp pencil, the chuck mechanism is moved forward during the centering process, and the locking means includes: (a) a rolling element receiving member provided in the shaft cylinder and having an inclined guide surface; (b) a rolling element disposed between the inclined guide surface and the outer surface of the slider and capable of locking the slider; (c) a rolling element holder that holds the rolling element and is elastically biased forward. (d) a pressing member provided on the outside of the chuck mechanism so as to be able to move back and forth as the chuck mechanism moves in the axial direction; and (e) a pressing member having an inner end engaged with the rolling element holder and an outer end. has a tiltable rotor that cooperates with the pressing member,
A sharp pencil capable of locking the slider formed by advancing the rolling element by tilting the rotor.