JP3286510B2 - Writing mechanism in composite writing instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing mechanism in a composite writing instrument for selectively injecting and retracting a plurality of writing bodies for a ballpoint pen, a mechanical pencil and the like by a cam action.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a composite writing instrument in which a plurality of writing bodies, for example, a mechanical pencil element and a ballpoint pen element are housed in a single barrel at the front. JP-B-55- 382
Japanese Patent Publication No. 80 discloses such a composite writing instrument. That is, in this conventional example, the slider (sliding cam)
A mechanical pencil element and a ball-point pen element are selected by a sleeve-shaped operating cam engaging with a shaft and two axially extending guide grooves which are diametrically opposed to each other, and are fixed to a rear end of the shaft case. It was a writing instrument used on a regular basis.

[0003]

However, in these structures, a writing mechanism for selectively appearing / leaving a plurality of writing objects is extremely complicated. That is, in the example in the above publication, a guide component having a complicated shape is interposed between a mechanical pencil element as a writing body and a ballpoint pen element. Accordingly, it is an object of the present invention to provide a writing mechanism in a composite writing instrument in which the guide mechanism having such a complicated structure is eliminated and the writing mechanism is simplified and the operation is reliable.

It is a further object of the present invention to provide a composite writing instrument in which the refill of a mechanical pencil and replacement of a ballpoint pen feel are simplified and operability is improved. Provides a writing mechanism in a composite writing instrument that does not spill when refilling the lead of a mechanical pencil and that can use a short ballpoint pen feel, and that minimizes the residue, that is, the loss, of rod-like objects such as erasers. The purpose is to do.

[0005]

According to the present invention, a plurality of refills are selectively slid in the axial direction so that the tips of the plurality of refills are made to protrude and retract from the distal end opening of the barrel. In a writing mechanism of a writing instrument, a plurality of refills that can slide in the shaft cylinder in the axial direction, sliding cams respectively attached to the rear ends of these refills, and a front part of these sliding cams. cam comprising an elastic body formed by biasing the sliding cam and the refill rearwardly abuts a locking portion for locking the selected refill at the writing position caused to selectively advance the sliding cam The sliding cams are disposed facing each other in a contact state, and guide the sliding cams to the outer wall of these sliding cams and the inner wall of the shaft cylinder in the axial direction. It is noted that the guide means of Writing mechanism in a combined writing tool to obtain.

[0006]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, a plurality of refills, one is a mechanical pencil refill 1, the other is a ballpoint refill 2,
A writing instrument mechanism having such a dual function is provided at the front,
At the rear is shown a composite writing implement with an eraser delivery mechanism.

This writing instrument comprises a front shaft 3 for housing a portion of a writing mechanism located at a front portion, and a rear shaft 4 for housing an eraser feeding mechanism located at a rear portion. A female screw 3 a is formed on the inner periphery of the rear portion of the front shaft 3. Then and center pole 5 is interposed between the rear axle 4 and these front barrel 3,
These form a shaft cylinder A.

[0008] As shown in FIGS.
A male screw 5a is formed in the small diameter portion at the tip of the shaft, and this portion is screwed with the female screw 3a of the front shaft 3, and is removed as necessary to replace or replace the lead of the mechanical pencil. . A stopper engagement piece 5b is integrally provided at the rear end of the center shaft 5, and two notches 5c functioning as knock allowance after assembly are formed on both sides of the engagement piece 5b in the axial direction. I have.

[0009] Between these notches 5c, there is an engaging piece 5
An intermediate guide portion 5d having an intermediate height between the upper side of the notch 5b and the bottom side of the notch 5c is formed, and a protrusion 10b of the cam body 10 described below is formed by radially extending the intermediate guide portion 5d from one of the notches 5c. After that, it moves between the other notches 5c, and when any of the notches 5c is reached, the refills 1 and 2 are selectively fed out. If the selected refill 1 is a mechanical pencil, it is knocked and moves axially in the notch 5c to draw out the lead.

Further, a pair of thick portions 5f facing the rear portion of the central shaft 5 are provided with through holes 5e, and four axially formed in the inner peripheral portion of the central shaft 5 at 90 ° intervals. 5 g of guide ribs are formed.

Further , one ends of return springs 6 and 7 for urging the refills 1 and 2 rearward, respectively, are locked to the front portion of the center shaft 5. The sliding cams 8 and 9 are attached to the rear portions of the refills 1 and 2 and are locked to the other ends of the return springs 6 and 7 (elastic bodies) to be urged rearward, respectively. As shown in FIGS. 5 to 11, these sliding cams 8 and 9, the cam operating portion 8a which allowed to advance to the selected択的presses any of the rear end of the refill 1, 2, 9a
At the front.

Further, the engaging grooves 8b, 9b (guide means) provided on the cam operating portions 8a, 9a are engaged with guide ribs 5g (guide means) provided on the inner wall of the center shaft 5, respectively. Smooth up and down movement of 8,9. Since the function for smoothing the vertical movement of the sliding cams 8 and 9 may be obtained, the engaging grooves 8b and 9b and the guide ribs 5g are reversed so that the former slides around the center shaft and the latter slides. The cams 8 and 9 may be formed. Further, in the above-described embodiment, the guide rib 5g is provided on the inner wall portion of the center shaft because the rod-shaped object feeding mechanism is provided on the rear portion. Is possible.

A D-shaped portion 8 is provided at the rear of the sliding cams 8, 9.
c, 9c, and the D-shaped portions 8c, 9c
It is slidably inserted inside the front end of the “0”. Therefore,
Fixed to the rear end of the two guide grooves and shaft case for diametrically opposed extending sleeve-shaped actuating cam axially to the slider engaging as in the conventional example described in Gazette of the Japanese Patent Publication 55- No. 38280 There is an advantage that a complicated configuration such as a guided guide is not required. 7 and 10, reference numerals 8d and 9d denote fitting adjustment projections for adjusting the variation in the pipe diameter of the refill formed by extrusion.

Next, as shown in FIGS. 12 to 14, the cam body 10 is engaged with the center shaft 5 to slide in the direction of the front shaft 3 and to be rotatable.
a is provided on the outer periphery thereof. If this point is explained in detail, the above-mentioned center shaft 5 has a pair of thick portions 5f facing the rear portion, and a through hole 5e.
When the front end of the cam body 10 is press-fitted into the center shaft 5, the ring-shaped engaging projection 10a pushes the thick portion 5f to open and inserts into the through-hole 5e to be rotatably fitted. It is slidable forward but locked rearward.

Although the cam body 10 is rotatable with respect to the center shaft 5, a stopper protrusion 10b is formed in the front outer wall of the cam body 10 in the axial direction, and the stopper protrusion 10b projects rearward of the center shaft 5. Since the rotation direction is regulated by the engagement piece 5b, the rotation is not made one rotation, but at most, an angle sufficient to select the sliding cams 8, 9; that is, the angle from one end edge to the other end edge of the engagement piece 5b. It is only turned between.

The outer diameter of the cam body 10 is preferably gradually reduced toward the rear so that it can be easily inserted from the front of the rear shaft 4 during assembly. The cam body 10 may be formed in a polygonal shape instead of the notch 10d, or may be simply press-fittable. Reference numeral 10f in the figure denotes a locking portion formed at the vertex of the cam operating portion at the front of the cam body 10.

Hereinafter, the operation of the composite writing instrument according to the embodiment of the present invention will be described. First, in order to project the core of a mechanical pencil is the rear axle 4 or clip 4b
When the cam body 10 is rotated while holding the cam body 10, the sliding cam 8 of the mechanical pencil refill 1 is driven forward by the operating portion of the cam body 10 and the cam body is protruded from the front end opening of the front shaft 3 when the front end thereof is projected. It is locked by a locking portion 10f formed at the front of the device 10. Lead tank 1a via sliding cam 8
Is also advanced. At this time, the rear end of the rear shaft 4 is knocked to release the chuck in the chuck ring from the chuck ring and the core can be extended. When the knock is stopped, the chuck retreats again and engages with the chuck ring to clamp the core. Write-enabled.

At the end of writing, the rear shaft 4 or the clip 4
If the cam body 10 is rotated in the reverse direction while holding the b, the refill can be stored in the shaft cylinder by the reverse operation. When it is desired to take out the other refill, it is preferable to further rotate in the same direction as the rotation direction when the other refill is stored.

On the other hand, when it is desired to use this writing instrument as a ballpoint pen, the cam shaft formed on the front portion of the cam body 10 can be formed by rotating the rear shaft 4 or the clip 4b in the direction opposite to the direction in which the refill 1 of the mechanical pencil is projected. Department
By 9a , the ballpoint pen refill 2 is advanced, protrudes from the opening of the front shaft 3, and can be written. After use, the refill 2 can be easily stored in the writing implement by rotating the rear shaft 4 or the clip 4b in the opposite direction.

Further, the refilling of the lead for the mechanical pencil and the replacement of the refill for the ballpoint pen can be easily performed by turning the front shaft 3 to release the screw engagement with the center shaft 4 and removing the front shaft 3. That is, a male screw 5a is formed at the small diameter portion at the front end of the center shaft 5, and this portion is screwed with the female screw 3a of the front shaft 3, and is removed as necessary to refill the lead of the mechanical pencil. Since it can be replaced, there is an advantage that it is free from the inconvenience of removing the entire rod feeding mechanism at the rear part and refilling the core or the like from the rear end.

At least one of the plurality of refills 1 and 2 is formed integrally with the sliding cam 8. That is, at least one of the plurality of refills 1 and 2 is a refill 1 of a mechanical pencil, and a lead tank 1a constituting the refill 1 is formed integrally with a sliding cam 8, and the tip of the refill 1 is If the pen tip 1b is press-fitted into the lead tank 1a in a detachable manner, the pen tip 1b is removed when the lead is refilled and the lead tank 1a is removed.
Since it can be replenished in a, there is an advantage that there is no fear of spillage. It is possible to further insert the shorter ball point pen refill thereto by forming a pipe-like connector integrated with the slide cam 9 to the rear of the ball point pen refill 2.

FIG. 17 shows a modification of the sliding cams 8 and 9, and reference numerals 8f and 9f denote side guide ribs, respectively. These ribs 8f, 9f are such that when the sliding cams 8, 9 are set in the cam body 10 with their planes facing each other, the outer diameter of their cross-sectional arcs is set to the inner circumference of the perfect circular shape of the cam body 10. To match. With the ribs 8f, 9f formed in this way, the sliding cams 8, 9 have an advantage that the frictional area between them becomes small and the inner wall of the cam main body 10 does not rattle, so that a smooth vertical movement can be obtained.

In the above-described embodiment, the case of two refills 1 and 2 has been described, but the case of three or more refills is also possible.

[0024]

Since the present invention has the above-described structure, the writing mechanism has a very simple structure and a reliable operation, and the operability is improved by simplifying the refilling of the lead and replacement of the ballpoint pen refill. It enables a writing mechanism in a composite writing instrument.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a composite writing instrument in which a writing instrument mechanism according to an embodiment of the present invention is incorporated.

FIG. 2 is a front view of the center axis of FIG. 1;

FIG. 3 is a longitudinal sectional view of a center axis of FIG. 1;

FIG. 4 is a plan view of the center axis of FIG. 1;

FIG. 5 is a front view of a sliding cam of the mechanical pencil refill of FIG. 1;

FIG. 6 is an enlarged plan view of the sliding cam of FIG.

FIG. 7 is a longitudinal sectional view of the sliding cam of FIG. 5;

FIG. 8 is a front view of a sliding cam of the ballpoint pen refill of FIG. 1;

FIG. 9 is an enlarged plan view of the sliding cam of FIG. 8;

FIG. 10 is a longitudinal sectional view of the sliding cam of FIG.

FIG. 11 is a plan view showing a state where the sliding cams of FIGS. 5 and 8 are set in a center shaft.

FIG. 12 is a front view of the cam body of FIG. 1;

FIG. 13 is a side view of the cam body of FIG.

FIG. 14 is a longitudinal sectional view of the cam body of FIG.

15 is a longitudinal sectional view of a modification of the sliding cam of the mechanical pencil refill of FIG. 5;

FIG. 16 is a longitudinal sectional view of a modified example of the sliding cam of the ballpoint pen refill of FIG. 8;

FIG. 17 is a plan view showing a further modified example of the sliding cam shown in FIGS. 5 and 8 set in a center shaft.

[Explanation of symbols]

 A Shaft tube 1 Mechanical pencil refill 1a Core tank 1b Pen tip 2 Ballpoint pen refill 3 Front shaft (shaft tube) 3a Female screw 4 Rear shaft (shaft tube) 4b Clip 5 Middle shaft (shaft tube) 5a Male screw 5b Engagement piece 5c Cutting Notch 5d Intermediate guide part 5e Through hole 5f Thick part 5g Guide rib (guide means) 6 Return spring 7 Return spring 8 Sliding cam 8a Cam operating part 8b Engagement groove (guide means) 8c D-shaped part 8d Projection 8f rib 9 slide Moving cam 9a cam operating portion 9b engaging groove (guide means) 9c D-shaped portion 9d protrusion 9f rib 10 cam body 10a engaging protrusion 10b stopper protrusion 10d notch 10f locking portion

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiichi Kobayashi 2-5-12 Irie, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Pencil Co., Ltd. Yokohama Office (72) Inventor Naoki Sekiguchi 2 Irie 2, Kanagawa-ku, Yokohama-shi, Kanagawa No. 5-12 Mitsubishi Pencil Co., Ltd. Yokohama Office (56) References JP-A-63-41198 (JP, A) JP-A-3-79397 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B43K 24/14 B43K 24/18

Claims (6)

(57) [Claims] 1. A writing mechanism for a composite writing instrument in which a plurality of refills are selectively slid in an axial direction so that tips thereof are made to protrude and retract from a tip end opening of a shaft cylinder. A plurality of refills, sliding cams respectively attached to the rear ends of these refills, and an elasticity which abuts on the front portions of these slide cams and urges the sliding cams and refills rearward. Body, and a cam body having a locking portion for selectively advancing the sliding cam and locking the selected refill at the writing position, wherein the sliding cams face each other in a contact state. A writing mechanism provided in the composite writing instrument, wherein guide means for guiding the sliding cam in the axial direction are provided on the outer wall of the sliding cam and the inner wall of the barrel. . 2. The guide means comprises a concave portion or a convex portion formed on an inner peripheral portion of the barrel, and a corresponding convex or concave portion formed on an outer wall portion of the sliding cam. 2. A writing mechanism for a composite writing instrument according to claim 1, wherein: 3. The shaft barrel comprises a front shaft, a center shaft, and a rear shaft, and the guide means includes an engagement groove provided on an outer wall of the sliding cam and a guide rib formed on an inner wall of the center shaft. The writing mechanism according to claim 1, wherein the writing mechanism comprises: 4. A sliding cam having a cam operating portion at a front portion and a rear portion having a D-shaped portion, wherein the D-shaped portion is slidably inserted inside a tip end portion of the cam body. The writing mechanism of the composite writing instrument according to claim 1, wherein: 5. The writing mechanism according to claim 1, wherein at least one of the plurality of refills is formed integrally with the sliding cam. 6. A refill for a mechanical pencil, wherein at least one of the plurality of refills is a refill for a mechanical pencil, and a lead tank constituting the refill is formed integrally with the sliding cam. A writing mechanism in the composite writing instrument according to 5.