JPH0353907Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a writing instrument, in particular, a number of short writing cores with sharp tips are inserted into a writing tube in series and can be used as needed. It relates to a writing instrument that can be drawn out.

(Prior art) Conventionally, a short writing core with a sharp tip, such as a pencil lead, is held at the lower end of the writing rod for writing, and the tip of the pencil lead wears out. Then, it was replaced with a new pencil lead with a sharp tip, eliminating the need to sharpen the tip of the pencil lead.
-There is a writing instrument described in Publication No. 176642. This conventional writing instrument will be explained with reference to FIGS. 6 to 12. Reference numeral 10 is a cylindrical outer writing tube with a hollow interior, its lower end 11 and upper end 12 each having a conical shape, and an opening 13, 14 have been established. Locking portions 15 and 16 are provided on the inner surface of the outer writing tube 10 in a protruding manner. Reference numeral 20 denotes a core loading hole 2 in which a large number of pencil leads 50 as writing cores can be accommodated in series.
1, which is fitted into the outer writing tube 10 so as to be freely advanced and retracted, and has an enlarged conical head 24 formed at its lower end, and has an opening 1 at the lower end 11 of the outer writing tube 10.
When it protrudes from 3, it is in a free state, and when it retreats, it engages with the opening 13. Further, the enlarged conical head 24 has two axial grooves 26 and 27, and sandwiched core portions 25 and 25 formed by dividing the enlarged conical head 24 by the grooves 26 and 27.
A front pipe duct 22 having a diameter slightly smaller than the diameter of the core loading hole 21 is formed in the core parts 25, 25.
Reference numeral 30 denotes a compression spring interposed between the outer tube 10 and the inner tube 20, the upper end of which is engaged with protrusions 29, 29 protruding from the outer surface of the inner tube 20. Through this protrusion 29, the inner tube 20
so that it is locked to the locking part 15 of the outer writing tube 10,
The inner tube 20 is urged upward to lock the protrusion 29 of the inner tube 20 to the locking portion 15 of the outer writing tube. The lower end of the compression spring 30 is connected to the locking portion 1 of the outer writing tube 10.
6, and the pushing core part 33 is integrally connected, and this pushing core part 33 enters into the split groove 27.
It is becoming possible to escape. When the inner tube 20 is at the lowest position due to the elasticity of the compression spring 30, the pushing core portion 33 enters the dividing groove 27, and the tip thereof is inserted into the inner tube 2.
0 core loading hole 21 and front pipe duct 22
and the pinched core portions 25, 25.
Lock the upper end of the pencil lead 51 held between the inner tube 2
0 is pushed downward and moves, the pushing lead part 33 is pushed by the upper end wall part of the dividing groove 27 and moves to the side, and the next pencil lead 52 above the pencil lead 51 is moved to the top of the pencil lead 51.
Move forward so that it is directly above the Then, when the downward pressure on the inner tube 20 is released and the inner tube 20 is restored upwardly by the elasticity of the compression spring 30, the tip of the pusher core portion 33 moves along the split groove 27, and the tip of the pusher core portion 33 returns to the core loading hole.
1 and is locked to the upper end of the second pencil lead 52, and as the inner tube 20 moves upward, the second pencil lead 52 is pushed by the tip of the pusher part 33 and becomes the first pencil lead. 51 is pushed out from the pinched core parts 25, 25, and the second pencil lead 52 is held between the pinched core parts in place of the first pencil lead 51.

(Problems to be Solved by the Present Invention) In the conventional writing instrument described above, the lower end of the compression spring is locked to the locking part 16 consisting of two protrusions, so as shown in FIG.
If the spring winding 31 at the lowest end of the pencil is inclined, the pusher lead part 33 may escape from the split groove 27, or the tip end 32 may hit one wall of the split groove as shown in FIG. There was a drawback that the feeding operation was not performed smoothly and the wall of the groove 27 was damaged. Furthermore, as shown in FIG. 14, when the root of the pushing core part 33 rides on the locking part 16, the tip of the pushing core part 33 moves outward from the center line of the core loading hole 21, and the pencil lead is removed. There was an inconvenience that it could come off from the upper end of 51, causing a malfunction.

The present invention has been made to improve the above-mentioned drawbacks of conventional writing instruments.

(Means for Solving the Problems) The present invention has been developed in view of the drawbacks of the above-mentioned conventional writing instruments.
An outer writing tube having openings at the upper and lower ends, respectively, and a number of short writing cores arranged in series, each of which is fitted into the outer writing tube so as to be freely retractable and has a sharp tip inside. It is formed to be inserted, has a protrusion protruding from its outer surface, and has an enlarged conical head at its lower end that advances and retreats from the opening at the lower end of the outer writing tube, and this enlarged conical head has an axial direction. an inner tube provided with a groove, and an inner tube interposed between the outer tube and the inner tube, the upper end of which is engaged with a protrusion of the inner tube to urge the inner tube upward;
The compression spring is provided at the lower end of the inner tube with a pushing core part that advances and retreats through the grooves of the enlarged conical head of the inner tube. A stepped portion is formed which engages and locks almost the entire lower surface of the lowermost winding, and this stepped portion is provided with a guide groove that corresponds to the split groove of the enlarged conical head of the inner tube, so that the compression spring There is provided a writing instrument characterized in that the pushing core portion guides the movement of the enlarged conical head of the inner tube toward and away from the split groove.

(Function) In the writing instrument of the present invention, substantially the entire lower surface of the lowermost winding of the compression spring comes into contact with and is locked to the stepped portion formed inside the lower end of the outer writing tube. Therefore, the lowermost winding of the compression spring does not tilt. Further, the direction of the pushing core portion is always maintained constant. In addition, since a guide groove is provided in the step part corresponding to the groove in which the pusher core advances and retreats, the pusher core does not escape from the groove, and there is no problem in the operation of feeding out the pencil lead. do not have.

(Example) Next, the writing implement of the present invention will be explained with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the writing instrument of the present invention, and 10 has an upper tapered part 12 and an upper opening 14 at the upper end, and a lower tapered part 11 and a lower opening 13 at the lower end. Outer writing tube; 20 is fitted into the outer writing tube 10 so as to be able to move forward and backward, and a core loading hole 21 into which a number of short writing cores 50 each having a sharp tip are inserted in series into the interior 21; A protrusion 29 is formed on the outer surface thereof, and an enlarged conical head 24 is formed at the lower end thereof, and the enlarged conical head 24 is inserted into and exited from the opening 13 at the lower end of the outer writing tube 10. As shown in FIGS. 2 and 3, the grooves 26 in the axial direction,
27 is provided to form the sandwiched core portions 25, 25; and 30 is the outer writing tube 10 and the inner tube 20.
The upper end is engaged with the protrusion 29 of the inner tube 20 to urge the inner tube 20 upward, and the lower end is inserted along the groove 27 of the enlarged conical head 24 of the inner tube 20. This is a compression spring in which a pushing core part 33 that moves forward and backward is integrally formed. A second protrusion 29A is provided at the upper end of the inner tube 20, and is engaged with the inner surface of the tapered portion 12 at the upper end of the outer tube 10 by the biasing force of the compression spring 30. Thus, the upward movement of the inner tube 20 is stopped in a fixed position. In addition, as shown in FIGS. 4 and 5, the outer writing tube 10
A stepped portion 11A is formed inside the lower end portion 11, and from this stepped portion 11A to the lower end opening 13 of the outer writing tube 10, the inner tube 20 can freely move, although the diameter is smaller than the inner diameter of the outer writing tube. A through hole 13A that can move forward and backward is provided, and an axial guide groove 17 is formed. and the lowest winding 3 of the compression spring 30
1 is adapted to be locked to this stepped portion 11A.

A front pipe duct 22 having a diameter slightly smaller than the diameter of the lead loading hole 21 but almost the same as the diameter of the pencil lead 50 is formed in the enlarged conical head 24 formed at the lower end of the inner pipe 20. When the protrusion 29A is in the uppermost position, that is, the position where the protrusion 29A is locked inside the tapered part 12 at the upper end of the writing tube 10, the enlarged conical head 24 engages with the lower end opening 13 of the writing tube 10. The pinching lead parts 25, 25 are pressed to squeeze the pencil lead 51 fitted into the front pipe duct 22. Then, when the inner tube 20 is pressed downward from the upper end and moves downward, and the enlarged conical head 24 advances to the outside to protrude from the lower end opening 13 of the outer writing tube 10, the pressure on the pinch core parts 25, 25 is released. Then, the pencil lead inserted into the front pipe duct 22 is released. In this position, as shown in Figure 15,
The pushing core portion 33 of the compression spring 30 is pushed up by the upper end wall portion of the split groove 27 and moved outward, so that the second pencil lead 52 is positioned above the first pencil lead 51. Then, when the pressure on the upper end of the inner tube 20 is released and the inner tube 20 moves upward by the elasticity of the compression spring 30, the pushing core part 33 of the compression spring 30 returns to the inside along the split groove 27 by its own elasticity. The tip is adapted to lock onto the upper end of the second pencil lead 52. Then, while the inner tube 20 reaches the uppermost position, the second pencil lead is inserted into the pushing core part 3 of the spring 30.
3 prevents the first pencil lead 51 from moving upward, and as a result, the first pencil lead 51 escapes from the front pipe duct 22 and the second pencil lead 5
2 is inserted into the front pipe duct 22 and sandwiched between the pinched core parts 25, 25, the enlarged conical head 24 engages with the lower end opening 13 of the outer pencil tube 10, and the second pencil lead 52 is pushed by the compression spring 30. While being locked to the core 33, it is squeezed by the pinched cores 25, 25.

In addition, the inner tube 20 has a dividing groove 27 that is connected to the outer tube 1.
The compression spring 3 is inserted into the outer writing tube 10 so as to correspond to the guide groove 17 provided in the stepped portion 11A of the
0, almost the entire lower surface of the lowermost winding 31 is in contact with the stepped portion 11A, and the pushing core portion 33 is in contact with the stepped portion 11A.
is configured to enter and exit the split groove of the inner tube 20 along the guide groove 17.

The method of using the writing instrument of this invention is mentioned above.
Since it is the same as that described in Publication No. 176642, its explanation will be omitted.

[Effect of idea]

As described above, the writing instrument according to the present invention has a stepped portion inside the lower end of the outer writing tube to lock the lower end of the compression spring so that almost the entire lower surface of the lowermost winding comes into contact with the stepped portion. As a result, the lowermost winding or pushing core part of the spring does not tilt, and a guide groove corresponding to the split groove of the inner tube is provided in the step part to prevent the pushing core part of the spring from protruding into the split groove of the inner tube. Since it is designed to guide the insertion, the push-in core part does not escape from the split groove, and the failures that occur with conventional writing instruments do not occur at all, making it possible to provide a highly reliable and easy-to-use writing instrument. .

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is a three-dimensional view showing the lower end of the inner tube, Fig. 3 is a sectional view taken along line A-A, and Fig. 4 is the lower end of the outer tube. 5 is a partially cutaway three-dimensional view showing the lower end of the outer writing tube, FIG. 6 is a vertical sectional view showing an example of a conventional writing instrument, and FIG. 7 is a cross-sectional view of the outer writing tube. A three-dimensional view, FIG. 8 shows the cap, FIG. 9 shows the compression spring, FIG. 10 shows the inner tube, and FIG. 11 shows a longitudinal sectional view of the lower end of the inner tube. FIG. 15 is an explanatory diagram showing a failure state of a conventional writing instrument, and FIG. 15 is an explanatory diagram showing one operation of the writing instrument of the present invention. In the figure, 10...external writing tube, 11A...stepped section,
13... Outer writing tube lower end opening, 15... Locking part, 16
... Locking part, 17 ... Guide groove, 20 ... Inner pipe, 2
1... Core loading hole, 22... Front pipe duct, 24... Enlarged conical head, 25... Pincer part, 26, 27... Division groove, 29, 29A... Protrusion, 31... Compression spring, 31... Winding wire, 3
3...Pushing core part, 50, 51, 52...Pencil lead.

Claims (1)

[Scope of Claim for Utility Model Registration] An outer writing tube having openings at the upper end and lower end, respectively, and a short-shaped writing tube that is fitted into the outer writing tube so as to be able to move forward and backward, and has a sharp tip inside. It is formed so that a large number of writing cores can be inserted in series, has a protrusion protruding from its outer surface, and forms an enlarged conical head at its lower end that is inserted into and exited from the opening at the lower end of the outer writing tube; This enlarged conical head is interposed between an inner tube provided with an axial groove, and the outer tube and the inner tube, and the upper end is engaged with a protrusion of the inner tube to connect the inner tube. A compression spring is biased upward to lock the upward movement of the inner tube in a fixed position, and a compression spring is integrally formed at the lower end with a pushing core portion that advances and retreats through the split groove of the enlarged conical head of the inner tube. In the device, a step portion is formed inside the lower end portion of the outer writing tube, and substantially the entire lower surface of the lowermost winding of the compression spring is brought into contact with and locked, and the step portion is provided with the step portion. A guide groove corresponding to the split groove of the enlarged conical head of the inner tube is provided so that the pushing core portion of the compression spring guides the advancing and retreating movement of the enlarged conical head of the inner tube with respect to the split groove. A writing instrument.