JPS6021280Y2 - Knot cap for extrusion type sharp pencil - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a knock cap included in an extrusion type writing instrument, and particularly relates to an improvement of a knock cap having a mark for extruding a writing lead.

Knock caps with markings for extruding writing leads are well-known, but the markings include one in which the outer periphery of the knock cap is colored, and one in which the outer periphery of the knock cap is marked 2 times toward the operation end. There are also those that are configured with different diameters, narrowing down to small diameters such as stages and three stages.

The former colored structure has the disadvantage that it peels off or fades with use and does not function as a writing lead extruder.
Although the latter configuration with different diameters has certain advantages, since no effort has been made to connect the knock cap to the base end of the core case, looseness occurs in the connection, and the knock cap often becomes loose. It has the disadvantage of falling off.

The present invention was developed by focusing on such a well-known knock cap, and makes it possible to use an axially long inward protrusion formed on the peripheral wall of the pipe body as a marker for extruding a writing lead, thereby improving the former well-known knock cap. The invention is characterized by eliminating the above-mentioned disadvantages, and by making the connection between the knock cap and the proximal end of the core case firm with the inward protrusion, thereby eliminating the fear that the knock cap will easily fall off. shall be.

To explain the embodiment of the present invention, the peripheral wall of the pipe body 1 has three
The inward protrusions 2 are longer in the axial direction and are squeezed out in the centripetal direction so that an inner diameter that matches the outer diameter of the core case 3 is formed, and an imaginary circle connecting the inward protrusions 2 is formed. It is adapted to the outer diameter of the core case 3, and when placed over the base end of the case, the inward protrusion 2 is brought into pressure contact with the core case 3 to prevent it from easily falling off.

The length of the inward protrusion 2 is configured to be approximately the same length as the stroke 1 for pushing out the writing lead held by the chuck 4 so that it cannot be written on until it is released and becomes available for writing, or slightly longer. Top plate 101 attached to the operating end of the pipe body 1
Press the inward protrusion 2 arranged on the operation end side of the pipe body 1.
When the starting end 201 of the shaft tube 5 reaches the base end of the shaft tube 5, the chuck 4 opens and the writing lead is released. The drawing stroke for the writing lead, which has been released from the chuck 4 and is now ready for writing, to be gripped by the chuck 4 again (from the edge of the chuck indicated by the solid line in figure b to the edge of the chuck shown in figure 0) The length is approximately the same as the length (stroke to the end of the eye) or is slightly longer (same length as the protrusion length of the pipe body that can protrude from the base end in the axial direction in Figure 0).

Therefore, the inward protrusion 2 of the knock cap configured as described above can be used as a marker for extruding a writing lead.

Next, the action of the mechanical pencil using the knock cap of the present invention will be explained with reference to FIG. 1. In the writing lead retracted state shown in FIG.
01 reaches the base end of the barrel 5, the retraction spring 9 is compressed, and at the same time, the chuck 4 and the tightening ring 6 covering the chuck move forward together, and the tightening ring 6 pushes against the barrel 5.
Although the chuck 4 engages with the stepped portion 501 and stops, the chuck 4 continues to move forward and escapes from the stopped tightening ring 6, opens, releases the writing lead, and causes it to protrude from the tip of the barrel 5.

When the writing lead is released, the chuck 4 is shallowly fitted into the moving ring 8 disposed on the cushion spring 7, as shown in Figure b.

When the starting end 201 of the inward protrusion 2 reaches the base end of the shaft tube 5 and the pushing operation is stopped, the retraction spring 9 interposed between the core case 3 and the inner fitting 10 fixed in the shaft tube 5 is released. The chuck 4 is pulled by the elastic force of , fits into the stopped tightening ring 6, and both return together to the original position, where the chuck 4 grips the writing lead and becomes ready for writing.

When pulling in a writable writing lead, use the top plate 10 as shown in figure 0.
1 until it reaches the base end of the barrel 5.

When the top plate 101 reaches the base end of the shaft cylinder 5, the stopper tube 301 protruding from the core case 3 comes into contact with the stopper tube 1001 protruding from the inner tool 10, stopping the chuck 4 from moving forward. urge

When the double projecting pipes 301 and 1001 come into contact, the chuck 4 fits into the movable ring 8 somewhat deeply, compressing the cushion spring 7 and stopping the movable ring 8 at the forward position.

At the same time as the chuck 4 stops, the cushion spring 7 rebounds.
The moving ring 8 is gradually pushed back, and the chuck 4 is gradually fitted deeper to grip and hold the writing lead.

When the top plate 101 stops pushing when it reaches the base end of the barrel 5, the retraction spring 9 springs, pushing back the lead case 3 as shown in Figure b, and at the same time retracting the chuck 4 that grips the writing lead. At the start, the chuck 4 is fitted onto the tightening ring 6 that is engaged with the stepped portion 501 of the barrel 5, and both are pulled to the original position shown in Fig. a, and the writing lead is pulled into the barrel 5.

When the chuck 4 starts retracting, the movable ring 8 also moves at the same time, but when this ring comes into contact with the tightening ring 6 that has returned to its original position, it separates from the chuck 4 and releases the cushion spring 7 due to its own weight.
Return to the top and return to the original position.

Therefore, the order of action is a→l) + C→b in Figure 1.
-4-a.

As described above, the present invention comprises three or more axially long inward protrusions on the peripheral wall of the pipe body, and the inner diameter formed by the virtual circle connecting the protrusions is set to a diameter that matches the outer diameter of the core case. Since it has been smoothed out, when the pipe body is placed over the base end of the core case, the inwardly directed protrusions come into pressure contact with the outer peripheral surface of the core case.

Therefore, it becomes possible to securely connect the pipe body to the core case, which has the effect of preventing the pipe body from easily falling off and rattling.

Since the length of the inward protrusion is approximately the same as the stroke for the chuck to grip and release the writing lead, the pipe body placed over the base end of the lead case is pushed and the pipe body When the starting end of the inward protrusion arranged on the operation end side reaches the base end of the shaft barrel, the chuck moves forward, escapes from the tightening ring and opens, releases the writing lead it was gripping, and releases the writing lead from the shaft. When the starting end reaches the base end of the barrel and the pushing operation is stopped, the pipe body and the inward protrusion return to their original positions, and the chuck refits into the tightening ring. Then return to the original position together and grab the writing lead in a state where you can write.

Therefore, there is an effect that the inward protrusion of the pipe body can be used as a marker for extruding a writing core, and even when the protrusion is used as a marker, there is an effect that problems such as peeling and fading do not occur.

In addition, if the drawing depth of the inward ridges of the pipe body is changed for each pipe body, the inner diameter formed by the virtual circle connecting the inward ridges can be changed for each pipe body. Even if the diameter of the other parts (both inner and outer diameters) is large, it can be installed on a thin core case.
This has the effect of widening the scope of use.

Therefore, the known knock caps can be significantly improved and the intended purpose can be distantly related.

[Brief explanation of the drawing]

The drawings show a mechanical pencil using the knock cap of the present invention; Fig. 1 is a partially longitudinal front view showing the action of the mechanical pencil, Fig. 2 is an enlarged longitudinal sectional front view of the main part,
FIG. 3 is a cross-sectional view taken along the line ■--■ in FIG. 2. In the figure, 1 is a pipe body, 2 is an inward protrusion, 3 is a core case, 4
is the chuck and 1 is the stroke.

Claims (1)

[Scope of utility model registration request] A knock cap for a push-out mechanical pencil in which the writing lead moves in and out of the tip of the barrel simply by pushing a pusher that protrudes from the base end of the barrel, and the knock cap has three or more knock caps on the peripheral wall of the pipe body. The inner diameter of the long inward protrusion in the axial direction is configured to have an inner diameter formed by an imaginary circle connecting the protrusion to a diameter that matches the outer diameter of the core case, and the length of the inward protrusion is determined by a writing method. The length is approximately the same as the extrusion stroke until the writing lead gripped by the chuck is released, and the length from the upper end of the inward protrusion to the top of the pipe body can be written on. The length is approximately the same as the stroke for retracting the writing lead until it is gripped again by the chuck.