CN113928042A - Rotary feeding writing tool - Google Patents

Abstract

The invention provides a rotary writing tool capable of keeping a front writing part protruding from a front opening hole in a straight state (linear state) in a state of being parallel to an axial center line of a penholder. A plurality of writing elements (9) are housed in a pen holder (2), each writing element (9) is supported by a guide tube (11) so as to be movable in the axial direction of the pen holder (2), and a front end writing part (9a) of one writing element (9) is selectively projected from an opening hole (6a) provided in a pen head part (6) of the pen holder by a cylindrical cam (15) which is fixed in the pen holder by receiving a relative rotation operation of the guide tube (11) with respect to the pen holder (2). The writing element (9) in a state where the front writing section (9a) protrudes from the opening hole (6a) is maintained in a straight state by forming the opening hole (6a) of the nib section (6) at a position eccentric from the axial center line of the penholder.

Description

Rotary feeding writing tool

Technical Field

The present invention relates to a rotary writing instrument that accommodates a plurality of writing elements in a barrel and selectively projects the tip end of the writing element from the front of the barrel.

Background

A writing instrument having a structure in which a plurality of writing elements (writing cores) are housed in a barrel and a tip writing section is selectively projected from a tip end of the barrel by a predetermined feed operation.

As a mechanism for feeding out one of a plurality of writing elements accommodated in a barrel, there is a mechanism called a rotary feed-out type in which a rear barrel is relatively rotated with respect to a front barrel to selectively extend and retract a front end writing portion of the writing element from an opening hole formed at a front end portion of the front barrel.

Various improvements and proposals have been made in the rotary feeding writing tool, and the applicant has made several proposals for the rotary feeding writing tool, and one example of the proposals is disclosed in japanese patent laid-open No. 2012-61605 (patent document 1).

According to the rotary feeding writing instrument disclosed in patent document 1, a slide block that slides in contact with a cam is disposed at the rear end of each writing element housed in a barrel. Accordingly, the cylindrical cam mounted in the rear barrel is rotated together with the rear barrel with respect to the front barrel, and the slide block is moved forward and backward by the cylindrical cam, whereby the front writing portion of one writing element can be selectively projected from the opening hole formed in the front end portion of the front barrel.

Further, according to the rotary feed writing instrument disclosed in patent document 1, for example, three writing elements (writing cores) housed in a barrel are supported by guide cylinders so as to be movable in the axial direction. The three writing elements are arranged in parallel to each other along the periphery of the axial center line while avoiding the axial center line of the barrel.

Further, a tip opening hole through which the tip writing section of the writing element is selectively drawn out and retracted is formed in a tip end portion of the pen tip, which is disposed at the tip end portion of the pen barrel and is formed, for example, in a conical shape. Therefore, a structure is adopted in which a front end opening hole for the front end writing part to be protruded and retracted is formed on the shaft center line of the barrel.

According to this configuration, only the writing element selected for writing is in a state in which the tip writing portion thereof is bent from a position avoiding the axial center line of the barrel toward the axial center line of the barrel, and is deformed non-linearly. Therefore, the front writing part protruding from the front opening hole is slightly bent with respect to the axial center line of the barrel, and this gives an appearance that it is uncomfortable for anyone to experience.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above-described conventional rotary-feed writing instrument, and a main object thereof is to provide a rotary-feed writing instrument which is configured such that a tip writing portion protruding from a tip opening hole can be kept in a straight state (linear state) in parallel with an axial center line of a barrel, and which is not visually inconsistent and well balanced as described above.

Means for solving the problems

In the rotary propelling writing instrument according to the present invention, the plurality of writing elements are accommodated in the barrel, each writing element is supported by the guide tube so as to be movable in the axial direction of the barrel, and the tip writing part of one writing element is selectively projected from the opening hole of the writing tip member provided in the barrel by the cylindrical cam fixed in the barrel by receiving the relative rotational operation of the guide tube with respect to the barrel, and the writing element in a state where the tip writing part is projected from the opening hole is maintained in a linear state by forming the opening hole of the writing tip member at a position eccentric from the axial center line of the barrel.

In this case, in a preferred embodiment, the following structure is adopted: the writing elements are three or more, a sliding block which is in sliding contact with the cylindrical cam to move the writing elements in the axial direction of the barrel is connected to the rear end of each writing element, and the cylindrical cam fixed in the barrel includes: the writing instrument includes a cam flat portion formed in an arc shape along a circumferential direction, a pair of left and right cam inclined surfaces formed to be tapered forward from both end sides of the cam flat portion, and a cam apex portion of a predetermined width connecting front ends of the pair of cam inclined surfaces, and a slide block coupled to the writing element abuts on the cam apex portion, whereby a front end writing portion of the writing element protrudes from an opening hole of the writing tip member, and in this state, the slide block coupled to another writing element is positioned on the cam flat portion.

Further, it is desirable that a cross-sectional shape of the nib member orthogonal to an axial direction of the barrel constitutes a non-perfect circular shape.

It is desirable that the barrel includes a front barrel and a rear barrel, the nib member is attached to a front end portion of the front barrel, the rear barrel is coupled to the front barrel by a coupling, the barrel is configured such that an alignment opening is formed in one of the nib member and the coupling in an axial direction, a protrusion is formed in the other of the nib member and the coupling to be inserted into the alignment opening in the axial direction, and the protrusion is inserted into the alignment opening in the front barrel, so that an alignment mechanism in an axial rotation direction is formed between the nib member and the coupling.

In a preferred embodiment, a ball-point pen tip is used as the tip writing part, and the ball-point pen tip is provided with a constricted part having an outer diameter gradually decreasing from a portion having the largest outer diameter toward the tip part in a concave curved shape.

In another preferred embodiment, one of the writing elements is preferably a stylus operable on a screen of an electronic device terminal.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the rotary propelling writing instrument of the present invention, the plurality of writing elements housed in the barrel are supported by the guide tube that is manually rotated so as to be movable in the axial direction. Then, the guide barrel receives a rotational movement to sequentially selectively protrude a front writing part of one writing element from an opening hole provided in a nib member of the cartridge under an interaction with a barrel cam fixed in the cartridge.

In this case, the opening hole of the pen tip member is formed at a position eccentric from the axial center line of the barrel, whereby the writing element having the tip writing part protruding from the opening hole can be maintained in a substantially linear state (straight state) in the barrel. Therefore, the problem that the tip writing section of the conventional rotary-feed writing instrument protrudes in a bent posture with respect to the axis of the barrel can be solved.

Further, since the cylindrical cam that projects the front end writing section of the writing element is provided with the pair of left and right cam slopes formed so as to be tapered forward, the replacement operation of the front end writing section can be performed regardless of which direction of the left and right directions the rotation operation of the guide cylinder is performed.

Thus, in the case of the rotary-feed writing instrument in which three or more writing elements are accommodated in the barrel, it is possible to quickly select a desired writing element.

Drawings

Fig. 1 is a perspective view showing an external appearance structure of a rotary feeding writing tool of the present invention.

Fig. 2 shows the entire structure of the rotary feeding writing tool, in which fig. 2 (a) is a front view and fig. 2 (B) is a central sectional view.

Fig. 3 is an enlarged sectional view taken along the line a-a of fig. 2 in the direction of the arrows.

Fig. 4 is a perspective view showing a state where the front barrel is removed and the writing element (cartridge) can be replaced.

Fig. 5 shows a state where the barrel is removed and the front writing part is fed out, fig. 5 (a) is a perspective view seen from the front surface side, and fig. 5 (B) is a perspective view seen from the back surface side.

Fig. 6 shows a state where the barrel is removed and the front writing part is housed, fig. 6 (a) is a perspective view seen from the front surface side, and fig. 6 (B) is a perspective view seen from the back surface side.

Fig. 7 is a developed view of the rotary feed writing instrument shown in fig. 1, exploded in parts, with fig. 7 (a) being a front view and fig. 7 (B) being a perspective view.

Fig. 8 illustrates a one-piece structure of the front barrel, fig. 8 (a) is a perspective view, fig. 8 (B) is a front view, and fig. 8 (C) is a central sectional view.

Fig. 9A shows a one-piece structure of the nib member, fig. 9A (a) is a plan view, fig. 9A (B) is a front view, fig. 9A (C) is a bottom view, and fig. 9A (D) is a central sectional view.

Fig. 9B shows a single structure of the nib member, fig. 9B (E) is a perspective view from the front end side, fig. 9B (F) is a perspective view from the rear end side with the top and bottom reversed, fig. 9B (G) is a left side view, and fig. 9B (H) is a right side view.

Fig. 10 illustrates a one-piece structure of the rear barrel, fig. 10 (a) is a perspective view, fig. 10 (B) is a front view, fig. 10 (C) is a central sectional view, and fig. 10 (D) is a right side view.

Fig. 11A shows a one-piece structure of the cylinder cam, fig. 11A (a) is a plan view, fig. 11A (B) is a front view, fig. 11A (C) is a central sectional view, and fig. 11A (D) is a bottom view.

Fig. 11B shows a one-piece structure of the cylinder cam, fig. 11B (E) is a perspective view, fig. 11B (F) is a left side view, and fig. 11B (G) is a right side view.

Fig. 12 shows a state where the barrel cam is about to be mounted on the rear barrel, fig. 12 (a) is a front view, fig. 12 (B) is a central sectional view, fig. 12 (C) is a perspective view, and fig. 12 (D) is an enlarged side view as viewed from the axial direction.

Fig. 13 shows a one-piece structure of the guide cylinder, fig. 13 (a) is a perspective view, fig. 13 (B) is a plan view, fig. 13 (C) is a front view, and fig. 13 (D) is a central sectional view.

Fig. 14 shows a one-piece structure of the coupling, fig. 14 (a) is a plan view, fig. 14 (B) is a front view, fig. 14 (C) is a central sectional view, and fig. 14 (D) is a perspective view.

Fig. 15 shows a one-piece structure of the knob, fig. 15 (a) is a perspective view, fig. 15 (B) is a front view, and fig. 15 (C) is a central sectional view.

Description of the reference numerals

1. Rotationally feeding out the writing tool; 2. a pen holder; 3. a front pen holder; 4. a rear penholder; 5. a coupling; 5a, a large diameter part; 5b, aligning and opening; 6. a nib member; 6a, an opening hole; 6d, a convex portion; 7. a knob; 8. a pen clip; 9. writing elements (ballpoint pen refills); 9a, a front end writing part (ball point pen point); 9b, necking down; 9c, writing a ball; 11. a guide cylinder; 11a, a guide hole; 11c, a rod body; 12. a slider; 12a, a small protrusion; 12b, a convex portion; 13. a coil spring; 15. a cylindrical cam; 15a, a cam flat; 15b, cam ramp; 15c, cam top; 16. a tail bolt joint; 17. tail bolt; l1, axial center line of the penholder; l2, axis of nib member opening hole; u1, front penholder unit; u2, rear barrel unit.

Detailed Description

The rotary feed writing instrument of the present invention will be described based on an embodiment using a ballpoint pen refill as a writing element.

In the drawings shown below, the same reference numerals are used to denote the same parts, but in some drawings, the reference numerals are used to denote the representative parts for the convenience of the paper, and the detailed description will be described with reference to the reference numerals used in the drawings that show the respective parts as units.

As shown in fig. 1 and 2 as an overall structure, the rotary propelling writing instrument 1 includes a barrel 2 having an outer contour including a front barrel 3 and a rear barrel 4, and the front barrel 3 and the rear barrel 4 are linearly connected by a coupling 5. A nib member 6 is attached to the tip end of the front barrel 3, and a tip writing portion (ballpoint pen tip) 9a of a ballpoint pen refill 9 as a writing element is configured to protrude from the nib member 6.

Further, a knob 7 is attached to the rear end portion of the rear barrel 4 so as to be rotatable with respect to the rear barrel 4, and the ballpoint pen tip 9a protruding from the nib member 6 can be selected by rotating the knob 7. Further, a proximal end portion of the clip 8 is attached to a rear end portion of the rear barrel 4 at a boundary portion between the rear barrel 4 and the knob 7.

As shown in fig. 4, three ball-point pen refills 9 are housed as writing elements in the barrel 2 so as to be parallel to the axis of the barrel 2. The three ballpoint pen refills 9 are held by guide barrels 11 disposed on the rear end side of the rear barrel 4 so as to be axially movable. Further, by providing at least one of the ballpoint pen refills 9 as an input pen that can be operated on the screen of the terminal of the electronic device, it is possible to use it for writing and input to the terminal, and it is possible to use it as a wide range of composite writing tools.

That is, a guide hole 11a described later into which the rear end portions of the three ballpoint pen refills 9 are inserted is formed in the guide barrel 11, and the slide block 12 is housed in the guide hole 11a as shown in fig. 5 to 7.

The slide block 12 is biased toward the inner bottom of the guide hole 11a by coil springs 13 arranged between the slide block and a spring support portion 14 attached to the front end of the guide tube 11. A small projection 12a (see fig. 2) formed so as to protrude from the distal end of the slide block 12 is fitted into the rear end of the ink storage tube of the ballpoint pen refill 9, and the ballpoint pen refill 9 is held by the slide block 12.

Therefore, when the replacement of the ballpoint pen refill 9 is desired, as shown in fig. 4, the front barrel 3 is pulled out from the coupling 5, the front barrel unit U1 is separated from the rear barrel unit U2, and the replacement of the ballpoint pen refill 9 is performed in this state. As a result, the slider 12 moves forward in the guide tube 11, and the rear end of the ballpoint pen refill 9 is disengaged from the small projection 12a of the slider 12 in a state where the coil spring 13 is compressed to the maximum. Then, a new ballpoint pen refill 9 is inserted, and the rear end portion of the ballpoint pen refill 9 is fitted into the small projection 12a of the slide 12, whereby the new ballpoint pen refill 9 is held again by the slide 12.

In this embodiment, when the replacement of the ballpoint pen refill 9 is desired, as described with reference to fig. 4, the front barrel unit U1 is axially pulled out from the rear barrel unit U2 and replaced, and when the front barrel unit U1 is attached to the rear barrel unit U2, the front barrel unit U1 is axially pushed toward the rear barrel unit U2, and the front barrel unit U1 is axially fitted (so-called loose fitting) to the coupling 5 on the rear barrel unit U2 side.

As shown in fig. 2, a lever 11c, which will be described later, is formed on the rear end portion side of the guide tube 11, and the knob 7 is attached to an end portion of the lever 11 c. Therefore, the guide cylinder 11 is configured to be axially rotated in a state where three ballpoint pen refills 9 are mounted by turning the operation knob 7.

As shown in fig. 2, 5 and 6, a cylindrical cam 15 is mounted in the rear barrel 4 so as to surround the rear half of the guide tube 11.

The guide cylinder 11 is rotated by the rotational operation of the knob 7, and accordingly, the protrusions 12B (see fig. 2, 5, and 6) formed on the slide block 12 are gradually raised along a cam slope 15B of the cylindrical cam 15, which will be described later, so that the slide block 12 moves forward, and the detailed configuration of the cylindrical cam 15 will be described later with reference to fig. 11A and 11B in which the cylindrical cam 15 is shown as a single piece.

As shown in fig. 1 and 2, the writing portion (ballpoint pen tip) 9a at the tip of the ballpoint pen refill 9 to which the advancing slider 12 is attached protrudes from the opening 6a of the pen tip member 6, and can write.

Hereinafter, each member constituting the rotary feeding writing instrument 1 will be described based on the drawings showing the unit of the component.

Fig. 8 shows a one-piece construction of the front barrel 3. The front barrel 3 is preferably formed in a cylindrical shape from a metal material such as aluminum, and the front end portion is obliquely cut to form an oblique cut portion 3a, and the rear end portion is cut in a state orthogonal to the axis. Furthermore, shallow grooves 3b are formed in a cylindrical surface on the outer side of the front barrel 3 in a concentrated manner at a plurality of locations around the axis, respectively, along the axial direction. When the writing instrument 1 is rotated and fed while being held, the front barrel 3 functions as a grip portion.

As shown in fig. 8 (C), the rear end inner periphery of the front barrel 3 is formed to be slightly thick to form a thick portion 3C. The thick portion 3c functions as a stopper for a thin-walled tube member 21 (see fig. 7) made of, for example, brass and disposed along the inner peripheral surface of the front barrel 3. That is, the tube member 21 is inserted from the side of the inclined cut portion 3a at the front end portion of the front barrel 3, is disposed in the front barrel 3, and the tube member 21 is positioned by the thick portion 3c functioning as a stopper.

Fig. 9A and 9B show a one-piece structure of the nib member 6. The nib member 6 is made of a resin material such as ABS (acrylonitrile butadiene styrene), and is attached to the distal end of the front barrel 3.

As described above, the opening hole 6a through which the ballpoint pen tip 9a protrudes is formed in the tip portion of the nib member 6. Further, a cylindrical portion 6b is formed on the rear end side of the nib member 6, and the cylindrical portion 6b is attached to the front barrel 3 in a state of being fitted into the pipe member 21 disposed in the front barrel 3.

Further, an abutting portion 6c that abuts along the inclined cut portion 3a of the front barrel 3 is formed obliquely to the tip member 6, and the rear half portion of the tip member 6 with the inclined abutting portion 6c as a boundary is housed and attached in the front barrel 3.

As shown in fig. 9A (D), in the nib member 6, an opening hole 6a formed in the tip end of the nib member 6 is formed at a position eccentric from the axial center line of the barrel 2.

That is, the axial center line L1 of the barrel 2 corresponds to the axis of the cylindrical portion 6b formed in the nib member 6, and the axis of the opening hole 6a of the nib member 6 is denoted by reference numeral L2.

This is because the ballpoint pen refill 9 in which the tip writing part (ballpoint pen tip) 9a protrudes from the opening hole 6a of the nib member 6 is located at a position slightly separated from the axial center line L1 of the barrel 2, and therefore the position of the opening hole 6a is intentionally eccentric to that.

This makes it possible to keep the ballpoint pen refill 9, the tip writing part 9a of which protrudes from the opening hole 6a, straight (in a straight state) in the barrel 2.

Therefore, since the nib member 6 of this embodiment has the above-described structure, the sectional shape of the nib member 6 perpendicular to the axial direction of the barrel 2 is configured to be a non-perfect circle shape, instead of the generally used conical nib member.

In the nib member 6, a convex portion 6d curved in an arc shape is formed integrally with the cylindrical portion 6b from the cylindrical portion 6b toward the rear end side. Three ribs 6e are formed on the arc-shaped inner peripheral surface of the convex portion 6d along the axial direction.

The convex portion 6d forms an alignment mechanism in the shaft rotation direction between the convex portion and an alignment opening 5b formed in the coupling 5, which will be described later.

In addition, the three ribs 6e function as: when the coupling 5 is brought into contact with the nib member 6 in a state where the shaft is not aligned in the rotational direction, the coupling 5 is prevented from being assembled in a state where a part of the coupling is pressed against the arc-shaped inner peripheral surface of the convex portion 6d formed on the nib member 6.

In the present embodiment, the open hole 6a of the nib member 6 is formed at a position eccentric from the axial center line of the barrel 2, and the ballpoint pen refill 9 having the tip writing part protruding from the open hole 6a is kept straight (in a straight state) in the barrel 2, but in addition to this, the ballpoint pen refill 9 used in the present embodiment is also studied on the shape of the tip writing part (ballpoint pen tip) 9 a.

That is, as shown in fig. 4 in an enlarged manner in which the writing portion (ballpoint pen tip) 9a at the tip of the ballpoint pen refill 9 is shown, the ballpoint pen tip 9a used in the ballpoint pen refill 9 is provided with a constricted portion 9b in which the outer diameter gradually decreases from the portion having the largest outer diameter of the ballpoint pen tip 9a toward the tip thereof in a concave curved shape. That is, the side surface of the constricted portion 9b is a concave curved surface, and the writing ball 9c is attached to the tip portion of the small diameter ball-point pen tip 9a by caulking.

By using the ballpoint pen tip 9a, not only can an appearance effect of making the pen tip look thin compared to a conventional ballpoint pen refill having a conical tapered portion at the pen tip, but also a practical effect of making the trace portion at the tip end easily visible during writing can be obtained.

In particular, the ballpoint pen refill 9 that is set in the writable state as described above is disposed so as to be kept straight (in a straight state) in the barrel 2, and the ballpoint pen tip 9a at the tip of the ballpoint pen refill 9 is a ballpoint pen tip having the constricted portion 9b in a concave curved surface shape, so that these structures work in cooperation with each other, and the rotary feed writing instrument 1 can contribute to unique beauty.

Fig. 10 shows a one-piece structure of the rear barrel 4. The rear barrel 4 is formed into a regular hexagonal tubular shape by press molding using aluminum as a raw material, for example. The front end portion is open, and the rear end portion is formed with an end surface 4a by bending. A pair of notches 4b are formed in the axial direction from the end surface 4a, and the pair of notches 4b serve as through holes for a pair of proximal ends of the clip 8.

The central portion of the end surface 4a is open and constitutes a through hole 4c to be described later, which is applied to a male screw 16a or the like of the tail plug 16.

The cylindrical cam 15, the guide tube 11, and the coupling 5, which will be described later, are inserted in this order from the front end opening side of the rear barrel 4, thereby forming a rear barrel unit U2 shown in fig. 4. Hereinafter, the respective members will be described in order.

Fig. 11A and 11B show a one-piece structure of the cylinder cam 15. The cylindrical cam 15 is made of a resin material such as POM (polyacetal), and as shown in fig. 11A (a), a front half portion 15A is formed in a cylindrical shape to form a cam forming portion, and a rear half portion 15B is formed in a smaller diameter to form a mounting portion, a shaft support hole, and the like of the cylindrical cam.

The front half portion 15A is formed with a cam flat portion 15A formed in an arc shape along the circumferential direction. Further, a pair of left and right cam inclined surfaces 15b are formed to taper forward from both end sides of the cam flat portion 15 a. The pair of cam slopes 15b are formed in arc shapes that are bilaterally symmetrical along the axial direction, and the leading ends thereof are connected to both ends of a cam apex 15c having a predetermined width.

Further, since the cam top 15c is a portion to be brought into contact with the convex portion 12b (see fig. 5 and 6) of the slide block 12 coupled to the selected writing element (ballpoint pen refill) 9, the cam top 15c is formed into a gentle concave shape as shown in the drawings, thereby improving stability.

In this embodiment, a pair of recessed portions 15d are formed at the boundary between the cam flat portion 15a and the cam inclined surface 15b, and the convex portions 12b of the slide block 12 connected to the other two unselected writing elements are located in the recessed portions 15d, respectively. Therefore, when convex portions 12b of each slide block 12 are fitted in the pair of concave portions 15d, an appropriate click feeling can be obtained.

The rear half 15B of the cylindrical cam 15 constitutes a small diameter portion 15e, and a pair of locking convex portions 15f are formed in the small diameter portion 15e in the vertical direction. A metal end plug 16 formed in an annular shape is attached to the small diameter portion 15e and the locking convex portion 15f (see fig. 7 and 12). The end plug 16 is used to mechanically attach the barrel cam 15 and the base end portion of the clip 8 to the rear portion of the rear barrel 4.

As shown in fig. 11A (C), a shaft hole 15g is formed in the small diameter portion 15e, and the rod body 11C of the guide cylinder 11 is inserted through the shaft hole 15g, thereby realizing a function of rotatably supporting the guide cylinder 11.

Four ribs 15h are formed in parallel in the axial direction on the cylindrical surface between the cam flat portion 15a and the small diameter portion 15 e. When the cylindrical cam 15 is inserted and fixed into the rear barrel 4, the ribs 15h come into contact with four points in the inner edge portion of the rear barrel 4 formed in a regular hexagonal cylinder shape, respectively, thereby restricting movement (play) of the cylindrical cam 15 in the axial rotation direction with respect to the rear barrel 4.

Fig. 12 shows a state where the barrel cam 15 is inserted into the rear barrel 4 and fixed. When the barrel cam 15 is inserted into the rear barrel 4, the end plug 16 is inserted into the small diameter portion 15e of the barrel cam 15. As described above, the pair of locking convex portions 15f are formed in the small diameter portion 15e of the cylindrical cam 15. The tail plug 16 is attached to the small diameter portion 15e in a state locked by the pair of locking convex portions 15f so as not to rotate.

Then, the cylindrical cam 15 is inserted into the rear barrel 4 so that the cam top portion 15C of the cylindrical cam 15 is in contact with the inner surface side of a surface 4d [ (see (C) of fig. 12) ] sandwiched between the pair of notch portions 4b formed in the rear barrel 4 formed in a regular hexagonal tubular shape.

As shown in fig. 12 (B), the tail plug 16 is provided with a male screw 16 a.

In the state shown in fig. 12, when the cylindrical cam 15 is pushed toward the rear portion in the rear barrel 4 in a state where the right and left base end portions of the clip 8 formed in a U shape are inserted into the pair of notches 4b formed in the rear barrel 4, the small diameter portion 15e of the cylindrical cam 15 and the male screw 16a of the plug 16 protrude from the male screw through hole 4c of the rear barrel 4.

In this state, a ring-shaped end plug 17 (see fig. 7) having a flange on an end surface thereof is screwed into a male screw 16a of an end plug adapter 16 protruding from the rear portion of the rear barrel 4, and the cylindrical cam 15 and the clip 8 are mounted to the rear portion of the rear barrel 4.

Further, fig. 3 shows an installation state thereof in a sectional view for a main portion including the barrel cam 15 and the clip 8 installed at the rear of the rear barrel 4.

Fig. 13 shows a one-piece structure of the guide cylinder 11. The guide tube 11 will be partially described, but the entire guide tube 11 is made of a transparent resin material such as PC (polycarbonate). Further, in the front half portion, guide holes 11a into which the rear end portions of the three ballpoint pen refills 9 are inserted are formed at equal intervals around the axis line and in parallel with each other.

Further, for each guide hole 11a, a slit 11b is formed along the longitudinal direction of each guide hole 11a so as to communicate with the side surface of the guide tube 11. Convex portion 12b (see fig. 2, 5, and 6) of slide block 12 housed in guide hole 11a is located outward of slit 11 b. Convex portion 12b of slide block 12 is configured to be movable in guide hole 11a while contacting cam slope 15b of cylindrical cam 15 described above. This causes the ballpoint pen refill 9 to advance and move.

In each guide hole 11a of the guide tube 11, a coil spring 13 is accommodated in the front side of the slide block 12, and the front end portion of each coil spring 13 is locked by a spring support portion 14 attached to the front end portion of the guide tube 11.

As described above, the small protrusions 12a (see fig. 2) formed so as to protrude from the front end of the slide block 12 are fitted to the rear end of the ink storage tube of the ballpoint pen refill 9, whereby the ballpoint pen refill 9 is held by the slide block 12 and the ballpoint pen refills 9 are biased in the backward direction by the coil spring 13.

A rod 11 having a small diameter and formed in a cylindrical shape is formed in the rear half of the guide cylinder 11, and a short groove 11d is formed in the rear end of the rod 11 in the axial direction. Further, a fitting portion 11e having an outer diameter in a concave-convex state along the axial direction is formed along the groove portion 11 d.

The rod 11 is connected to a shaft hole 15g of a cylindrical cam 15 fitted in the rear end of the rear barrel 4 in an inscribed manner, and the guide barrel 11 is supported to be rotatable, and the groove 11d and the fitting portion 11e are projected from the rear barrel 4 to fit the knob 7 in a state where the writing instrument 1 is fed out by rotation after being fitted.

Fig. 14 shows the one-piece construction of the coupling 5. The coupling 5 is also made of a resin material such as ABS, similarly to the nib member 6, and the coupling 5 is attached to the front end of the rear barrel 4.

That is, after the cylindrical cam 15 and the guide barrel 11 are inserted into the rear barrel 4, the coupling 5 is finally attached to the front end of the rear barrel 4.

The coupling 5 is formed in a cylindrical shape as a whole, and a large diameter portion 5a is formed at a substantially central portion in a longitudinal direction thereof. The front half (left side in fig. 14) of the large diameter portion 5a is inserted into the rear end of the front barrel 3, and is aligned in the axial rotation direction with the nib member 6 inserted into the front end of the front barrel 3.

Therefore, a positioning opening 5b having a relatively wide width is formed in a partial groove shape on a side surface of the cylindrical body at a distal end portion of the coupling 5. The protruding portions 6d of the nib member 6 attached to the distal end portion of the front barrel 3 are aligned with each other so as to enter the alignment opening 5b, thereby aligning the nib member 6 and the coupling 5 in the axial rotation direction.

A cylindrical portion 5c is formed between the wide alignment opening 5b of the coupling 5 and the large diameter portion 5a, and a narrow slit 5d is formed in a part of the cylindrical portion 5c so as to be continuous with the wide alignment opening 5 b.

A fitting sleeve 22 (see fig. 4 and 7) formed in a cylindrical shape from a thin-walled metal or other material is attached to the cylindrical portion 5c, and as shown in fig. 4, the rear end portion of the front barrel 3 constituting the front barrel unit U1 is loosely fitted into the fitting sleeve 22.

Therefore, the fitting sleeve 22 is easily damaged, and replacement may be necessary. The slit 5d formed in the cylindrical portion 5c is provided to facilitate reduction of the outer diameter of the cylindrical portion 5c when the fitting sleeve 22 is replaced.

The rear half of the coupling 5 has an engaging portion 5e for the rear barrel 4, and the outer surface thereof is formed in a regular hexagonal prism shape. The fitting portion 5e is inserted into and fitted into the front end opening of the rear barrel 4 formed in a regular hexagonal tubular shape, whereby the coupling 5 is attached to the front end portion of the rear barrel 4.

When the coupling 5 is fitted to the rear barrel 4, it is necessary to perform fitting after the alignment is performed so that the position of the alignment opening 5b formed in the coupling 5 is located on the opposite side of the clip 8 attached to the rear barrel 4.

By performing the above-described alignment and attaching the coupling 5 to the rear barrel 4, the convex portion 6d of the nib member 6 attached to the front end portion of the front barrel 3 enters the alignment opening 5b formed in the coupling 5, and thereby the alignment in the axial rotation direction between the nib member 6 and the coupling 5 can be performed.

This positioning is also performed when the front barrel unit U1 is attached to the rear barrel unit U2 as shown in fig. 4, whereby the ballpoint pen tip 9a of the ballpoint pen refill 9 selected as the writing section can be projected in a state of being kept straight from the opening hole 6a formed in the pen tip member 6 at a position eccentric from the axial center line of the barrel.

As described above, when the joint 5 is attached to the rear barrel 4, the guide tube 11 accommodated in the rear barrel 4 is pressed by the joint 5, and the groove 11d and the fitting portion 11e formed in the rod body 11c protrude from the rear portion of the rear barrel 4. The knob 7 is attached to the rear end of the rear barrel 4 by the groove 11d and the fitting portion 11e formed in the rod 11 c.

Fig. 15 shows a one-piece structure of the knob 7. The knob 7 is formed with a knob portion 7a having a reduced outer diameter toward the rear end side, and at the rear end thereof, mark recesses 7b, which are recesses colored in three places along the circumferential direction, are formed. In the mark recessed portion 7b, it is preferable to apply a color corresponding to each ink color (for example, red, green, and black) of the ballpoint pen refill 9 attached to the rotary feed writing instrument 1.

Further, a mounting hole 7c having an inner diameter narrowed in a stepwise manner is formed on the axis of the knob 7, and a fitting portion 7d having an inner diameter in a concave-convex shape along the axial direction and a rib 7e protruding in the axial direction are formed at the deepest portion of the mounting hole 7 c.

The knob 7 is attached by pressing the attachment hole 7c into a rod body 11c of the guide barrel 11 protruding from the rear end of the rear barrel 4.

At this time, an O-ring 18 (see fig. 2 and 7) is preferably attached to a small diameter portion 15e of the cylindrical cam 15 protruding to the rear of the rear barrel 4, and a ball 19 (see fig. 2 and 7) is preferably inserted into the attachment hole 7c of the knob 7.

Then, the rib 7e formed in the mounting hole 7c of the knob 7 is aligned with the groove 11d formed in the rod body 11c of the guide tube 11, and the knob 7 is pushed toward the rod body 11c in this state. By this press-fitting operation, the concave-convex fitting portion 7d of the knob 7 is fitted and coupled to the concave-convex fitting portion 11e on the lever body 11c side.

This allows the guide tube 11 in the rear barrel 4 to be rotated in response to the rotation operation of the knob 7.

Further, since the rib 7e formed in the mounting hole 7c of the knob 7 is mounted so as to be aligned with the groove portion 11d of the shaft body 11c, the tip writing portion 9a of the ink color corresponding to the marking recess 7d located on the clip 8 side can be linked so as to protrude from the opening hole 6a of the nib member 6.

According to the rotary writing instrument having the above-described configuration, the guide barrel 11 in the barrel 2 is rotated by the rotation operation of the knob 7, and the slide block 12 moves forward along the cam slope 15b of the cylindrical cam 15 fixed in the barrel 2 in accordance with the rotation of the guide barrel 11. As a result, writing element 9 coupled to slide block 12 moves forward, and tip writing section 9a protrudes from opening 6a of nib member 6, and becomes writable.

By further turning operation of the knob 7, the writing element 9 is retreated by the urging force of the spring 13, and the newly selected adjacent writing element 9 is advanced in the same manner as described above, and the writing state is repeatedly made.

In this case, the opening hole 6a of the nib member 6 is formed at a position eccentric from the axial center line of the barrel, and thus the writing element 9 having the tip writing portion 9a protruding from the opening hole 6a can be maintained in a substantially linear state (straight state) in the barrel. Therefore, the problem of poor appearance of the conventional rotary feed writing instrument in which the distal writing portion 9a protrudes in a curved posture with respect to the axis of the barrel can be solved.

Further, since the cylindrical cam 15 for projecting the front end writing portion 9a of the writing element 9 is provided with the pair of left and right cam slopes 15b formed to be tapered forward, the operation of extending and retracting the front end writing portion 9a can be performed regardless of which direction the knob 7 is rotated in.

Thus, in the case of the rotary-feed writing instrument in which three or more writing elements 9 are accommodated in the barrel, there is provided a rotary-feed writing instrument which can rapidly perform the operational effects described in the effect section of the above invention, such as selection of a desired writing element.

In the aligning mechanism in the shaft rotation direction formed between the coupling 5 side and the nib member 6 side in the above-described embodiment, the aligning opening 5b is formed on the coupling 5 side, and the convex portion 6d inserted into the aligning opening 5b is formed on the nib member 6 side.

However, the positioning mechanism having the same operational effects can be realized by replacing the positioning opening 5b and the convex portion 6d with each other and by providing a mechanism corresponding to the positioning opening 5b on the nib member 6 side and a mechanism corresponding to the convex portion 6d on the coupling 5 side.

Claims (6)

1. A rotary feed writing instrument in which a plurality of writing elements are housed in a barrel, each writing element is supported by a guide tube so as to be movable in an axial direction of the barrel, and a front end writing portion of one writing element is selectively projected from an opening hole of a writing tip member provided in the barrel by a cylindrical cam fixed in the barrel by receiving a relative rotation operation of the guide tube with respect to the barrel,

the writing element in a state in which the tip writing section protrudes from the opening hole is maintained in a linear state by forming the opening hole of the pen tip member at a position eccentric from the axial center line of the pen shaft.

2. The rotary feed writing instrument of claim 1,

a slide block which is in sliding contact with the cylindrical cam to move the writing elements in the axial direction of the barrel is connected to the rear end of each writing element,

the cylinder cam fixed in the barrel has: a cam flat portion formed in an arc shape along a circumferential direction, a pair of left and right cam inclined surfaces formed to taper forward from both end sides of the cam flat portion, and a cam top portion of a predetermined width connecting front ends of the pair of cam inclined surfaces,

when the slide block connected to the writing element abuts on the cam top, the writing part at the front end of the writing element protrudes from the opening hole of the pen point member, and in this state, the slide block connected to another writing element is positioned at the cam flat part.

3. The rotary feed writing tool of claim 1 or 2,

the section of the pen point component, which is orthogonal to the axial direction of the pen holder, is in a non-perfect circle shape.

4. The rotary feed writing tool of claim 1 or 2,

the pen holder comprises a front pen holder and a rear pen holder, the pen point component is arranged at the front end part of the front pen holder, and the rear pen holder is connected with the front pen holder by means of a coupler so as to form the pen holder,

an alignment opening is formed in one of the nib member and the coupling in the axial direction, and a convex portion inserted into the alignment opening in the axial direction is formed in the other of the nib member and the coupling,

and inserting the convex part into the alignment opening in the front penholder so as to mutually form an alignment mechanism in the shaft rotation direction between the pen point component and the coupling.

5. The rotary feed writing tool of claim 1 or 2,

a ball-point pen tip is used as the tip writing part, and the ball-point pen tip is provided with a constricted part having an outer diameter gradually decreasing from a portion having the largest outer diameter toward the tip part in a concave curved shape.

6. The rotary feed writing tool of claim 1 or 2,

at least one of the writing elements is an input pen capable of operating on a screen of the electronic equipment terminal.

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