Push-out-type writing implement

BACKGROUND OF THE INVENTION

This invention relates to a push-out-type writing implement, that is, pens and/or pencils of click type or push-out type; particularly to ones, in which one of writing element(s) in a main shaft is brought forward to be pushed out by slide-wise handling from outside.

In recent years, various kinds of such click-type or push-out-type writing implements are in widespread use. For example, there are commercialized a kind of writing implements in which a writing element is pushed out from and pulled into a shaft body or barrel through one-touch operation, as well as a kind of ballpoint pen that is constructed as capable of switching between three or four colors.

For most of conventional ones of push-out-type writing implements, a plurality of refills are accommodated in a hollow shaft body; and handling tips or manipulator pieces are connected to rear ends of the refills and engaged in sliding grooves as readily advanced and retracted. Only one of the refills protrudes from the forefront tip of the main shaft when one of the manipulator pieces is pushed forward and secured as locked at this position. When another one of the manipulator pieces is pushed, the already protruded one of the manipulator pieces is retracted while another refill connected to the newly pushed manipulator piece is protruded forward and become available for writing or drawing in another color. When to return and accommodate all the refills into the shaft body, either one of retracted manipulator piece is slightly pushed forward; and thereby locking of the protruded manipulator piece is lifted as to be restored to an original position by action of a restoration spring. Such restoration spring is attached to each of the manipulator pieces.

According to such construction of the conventional writing implements, one of the manipulator pieces is pushed forward and then toward central axis of the shaft body, to be locked in the sliding groove. Thus, such motion has to be allowed in a writing implement, and therefore, there arises a problem that diameter of the shaft body becomes inevitably large.

When to conduct advancing and retracting of the writing elements as well as switching operation in the writing implements, in general, manipulator pieces disposed at rear end of the shaft body is pushed and slid by pressing with a thumb. To conduct such a motion, a user has to loosen and re-grip the shaft body on beforehand of such pressing. The advancing and retracting as well as switching operation would not be achievable by a hand when the writing implement is continuously gripped by the hand.

Present invention is made in view of the above, and is aimed to reduce diameter of shaft body by avoiding a large positional shifting of the writing element. It is further aimed to simplify and reduce assembling procedures and parts, even when the writing element is pushed out by a hand constantly gripping the shaft body, and to enable improvement in ornamental appearance of the writing implements.

BRIEF SUMMARY OF THE INVENTION

According to first aspect of the invention, a writing implement comprising: a plurality of manipulator pieces disposed on outside; a plurality of actuator pieces moved by respective one of the manipulator pieces, in at least foreword and rearward directions; writing elements arranged in a hollow main shaft as to be slidable along an inner face of the main shaft; springs each applying rearward stress on respective one of the actuator pieces; each of said actuator pieces comprising: a first projecting piece projecting in a traverse-sectional wise direction of the main shaft, at forefront part of the actuator piece; and a second projecting piece likewise projecting in a traverse-sectional wise direction of the main shaft, as disposed as distanced from the first projecting piece by a predetermined length; said main shaft having a small-internal-diameter part in vicinity of rearmost retracted position of the first projecting portion, and having a large-internal-diameter part larger in a diameter of the small-internal-diameter part at least in a region forefront of the small-internal-diameter part; said second projecting piece having a cam face as shaped for creating a stress in the traverse-sectional wise direction when another second projecting portion of other one of the actuator pieces axially bears down thereto; and each of said actuator pieces being connectable with respective one of the writing elements.

By such features, shape-wise construction at inner face of the shaft body and at actuating tips are simplified, as to enable cost reduction and reduction of diameter of the shaft body.

According to second aspect of the invention, a writing implement further comprising another cam face on the first projecting portion, for creating a stress in a traverse-sectional wise direction when said another second projecting portion of other one of the actuator pieces axially bears down thereto. By such features, the actuators are moved smoothly and reliably.

According to third aspect of the invention, a laterally-gathered bunch of said forefront part of the actuator pieces has a diameter substantially same with that of a laterally-gathered bunch of rear end faces of the writing elements connected with the actuator pieces.

According to fourth aspect of the invention, each of said manipulator pieces is exposed at a part to be gripped at writing or in vicinity of such to-be-gripped part and is connected with respective one of the actuator pieces as transmitted with handling force applied on the actuator piece. By such features, switching between the writing elements as well as retraction of the writing element at writing position are made by a hand continuously gripping the writing implement and without re-gripping motion.

With respect to connection between the actuator and manipulator pieces as to enable transmittance of hand-applied force, it is adoptable a connection using a connector piece or rod between the actuator and manipulator pieces. Not only such connection, it is also adoptable a connection through a refill or writing element itself onto which the manipulator and actuator pieces are respectively attached.

According to fifth aspect of the invention, each of said manipulator pieces is formed as connected with respective one of the actuator pieces and is exposed to outside from a through hole provided on the main shaft. By such features, the manipulator piece and the respective actuator piece may be integrally formed with each other, as to enhance reliability and to simplify a construction.

According to sixth aspect of the invention, at least one of said writing element is a mechanical pencil, and said actuator piece is attached on rear end portion of a fastener-bearer of the mechanical pencil. By features of the invention, a force of fastening a pencil lead in a mechanical pencil is enhanced to be substantially same with the single-use or non-multiplex mechanical pencil. To contrary, a conventional multiplex writing implement having a mechanical pencil element has a problem of low fastening force for holding the pencil lead and enduring a relatively strong writing pressure, because it is the lead casing that is held by a main structure.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1

is a longitudinal sectional view of a writing implement in first embodiment;

FIG. 2

is a transverse sectional view of the writing implement shown in the

FIG. 1

;

FIG. 3

is an enlarges partial view of

FIG. 1

, showing an essential portion of the writing implement;

FIG. 4

is another transverse sectional view of the writing implement shown in the

FIG. 1

;

FIG. 5

is a transverse sectional view showing a writing state or a state available for writing, of the writing implement of the

FIG. 1

;

FIG. 6

is a perspective view showing an external shape of a main shaft of the writing implement of the

FIG. 1

;

FIG. 7

shows the writing implement disposed with a gripper element;

FIG. 8

shows a modified embodiment by a longitudinal sectional view corresponding the

FIG. 3

;

FIG. 9

shows another modified embodiment by a longitudinal sectional view corresponding the

FIG. 3

;

FIG. 10

shows a traverse sectional view of the writing implement shown in

FIG. 9

;

FIG. 11

is a longitudinal sectional view showing a writing implement of second embodiment;

FIG. 12

is a longitudinal sectional view showing an essential portion of the writing implement of the

FIG. 11

;

FIG. 13

is a transverse sectional view showing a writing state of the writing implement of the

FIG. 11

;

FIG. 14

is an enlarges partial view of the

FIG. 13

, showing an essential portion;

FIG. 15

is a transverse sectional view of the writing implement shown in the

FIG. 11

;

FIG. 16

is a perspective view showing an actuator piece. of the second embodiment, appeared especially in

FIG. 14

;

FIG. 17

is a longitudinal sectional view showing essential part of a writing implement in third embodiment;

FIG. 18

is a perspective view showing actuator and manipulator pieces of the writing implement of the

FIG. 17

;

FIG. 19

shows a writing state of the writing implement of the

FIG. 17

; and

FIG. 20

shows the rearmost part of the writing implement of the fourth embodiment.

DETAILED DESCRIPTION OF THE INVENTION

First embodiment of the present invention will be described with reference to

FIGS. 1-7

.

FIG. 1

shows a push-out-type writing implement

1

, which is comprised of; a rear cap

2

; main shaft

3

whose rear end is closed by the rear cap

2

; four writing elements

4

accommodated in the main shaft

3

; and a front shaft

5

that forms an opening for pushing out and retrieval of writing tip

4

a

of the writing element

4

.

As shown in

FIG. 1

, the four writing elements

4

accommodates, which are ball-point-pen refills in colors different with each other, has a rear end portions

4

b

that extends to penetrate through an actuator piece

6

and supporter portion

3

a

, so as the rear end portions

4

b

reach rear part of the main shaft

3

. At rearward of the of the actuator piece

6

, as shown in

FIG. 2

, a supporting portion

3

a

is integrally formed on inner face of the shaft body

3

for supporting a spring

7

and an actuator piece

6

or the like; a refill bearer

8

is formed at rear part of the shaft

9

; and a restoration spring

7

is attached to the refill bearer

8

. The refills

4

and the restoration springs

7

are held by the supporter portion

3

and the refill bearer

8

in a manner that the restoration springs

7

constantly applies a rearward stress on the actuator pieces

6

and refills

4

.

The actuator pieces

6

are for pushing out and retrieval of the writing element

4

or for switching between colors, in response of moving of manipulator pieces

10

that are provided on outside of large-internal-diameter part

3

b

of the main shaft

3

. The actuator piece

6

acts in this manner when respective manipulator piece

10

is slide-wise moved with a thumb or the like while the main shaft

3

being gripped with a hand in a position of writing. The each actuator piece

6

is connected with the respective manipulator piece

10

through a connector

11

, the connection being made from inside to outside of the main shaft

3

.

The actuator pieces

6

are formed as rod-shaped pieces elongated in an axial direction having same shape. At forefront end of each of the actuator pieces

6

, there is formed a first projecting portion

6

a

having a substantially right-angled sector shape expanding in a radially outward direction. Circumferential faces of the first projecting portions

6

a

substantially coincide with an inner face of the main shaft

3

; and the first projecting portions

6

a

has a cam face

6

b

that is sloped as tapered toward its projecting end.

At rear end of each of the actuator pieces

6

, there is formed a second projecting portion

6

c

having a sector form in a cross section as in same manner with the first projection, which has a slope

6

d

at convex surface thereof. Projecting-wise dimension of the each second projecting portion

6

c

is smaller than that of the each first projecting portion

6

a.

Four of the actuator pieces

6

, in correspondence with number of the refills, are arranged along an inner face of the main shaft

3

having a hollow cylindrical shape; in a manner that the first projecting portions

6

a

in a sector-shaped cross section are tightly press-contacted with each other in a lateral or traverse direction of the main shaft

3

. A laterally outward propelling force is created by the cam faces

6

b

,

6

d

when one first projecting portion

6

a

of one actuator piece

6

axially bears down, or contacts as axially approached, to another first projecting portion

6

a

′ that belongs to an other actuator piece

6

′. Such propelling force is also created when the other first projecting portion

6

a

′ axially bears down to the second projecting portion

6

c

of the one actuator piece

6

.

If either one of the actuator pieces

6

is moved forward, the first projecting portion

6

a

comes ahead of the other first projecting portion

6

a

′, thereby forming a gap space or a clearance in a lateral direction, at inside of the main shaft

3

. Then, to the gap space, the second projecting portion

6

c

at rear side comes forward. The second projecting portion

6

c

comes to bear on the other first projecting portion

6

a

′ as to effect pushing-out action on the other first projecting portion

6

a

in the laterally outward direction, by the sloped cam faces

6

b

′,

6

d

of these projecting portion. Consequently, the second projecting portion

6

c

is pushed out ahead of the other first projecting portion

6

a

′ of the other actuator pieces

6

′.

If acting-on force is lifted after the pushing out action, the restoration spring

7

applies a rearward pulling force on the actuator piece

6

a

. Then, the one second projecting portion

6

c

thus stressed rearward is prevented from rearward shifting by a set of other three first projecting portions

6

a

′ that are arranged as tightly continued with each other in circumferential direction. Thus, a writing element

4

connected with the one second projecting portion

6

a

is kept in a pushed out position as shown in

FIG. 5

, thereby writing being enabled. When an other actuator piece

6

′ is moved forward at such writing-enabled state, one other first projecting portion

6

a

′ comes off from the tightly continued arrangement that has been in support of the one second projecting portion

6

c

positioned at the writing-enabled state. Thus, each of the three other first projecting portions

6

a

′ is allowed to move laterally outward by action of the cam face

6

a

′; and the second projecting portion.

6

c

returns backward to pass over the other first projection

6

a

′ and then to a retracted position.

If the one other actuator piece

6

′ is continuously moved forward, this actuator piece

6

′ is pushed ahead of the first projecting portions

6

a

. Then, after lifting of hand-applied force, a writing element

4

connected to the actuator piece

6

′ is kept in a position to be readily available for writing.

The actuator piece

6

may be provided with a third projecting portion, not shown in the figure, at between the first and second projecting portions

6

a

,

6

c.

The actuator

6

explained above moves as adopting single-stroke shifting between two latched positions in respect of the first and second projecting positions

6

a

,

6

c,

respectively corresponding an accommodated state and a writing-enabled state. Nevertheless, two-stroke slide-wise shifting action is adoptable in which the actuator

6

momentarily stops at a position in respect of the third projecting portion. By such construction, children with small hand or elder people easily make shifting operation.

At outside of substantially central part of the main shaft

3

, as shown in

FIG. 6

, manipulator pieces

10

are arranged for forward and rearward shifting of the actuators

6

as to facilitate protruding and retracting of the writing element

4

a

from tip of the forefront shaft

5

and to thereby keep or evade from the position for writing. The manipulator pieces

10

are engaged as readily slidable in a guide slit

12

and guide groove

13

that are bored at outside of the main shaft

3

. The guide slit

12

has a length required for forward shifting of the actuator piece

6

from an original retracted position at rear, to a forefront latched position available for writing. The guide slit

12

has a width-wise dimension for penetrating a connecting bit

11

a

that connects the manipulator piece

10

with a connector

11

, from outside to inside of the main shaft

3

. At rear of the slit

12

, the guide groove

13

is disposed as slightly recessed from outer main surface of the main shaft

3

. At forefront of the guide slit

12

and as to be continuous with the guide slit

12

, a wide slit

14

is disposed which have a length substantially equal to that of the guide slit

12

and have a width wider than that of the manipulator piece

10

.

The manipulator piece

10

has a shape elongated in a longitudinal direction of the main shaft

3

and has a rugged face or knurled face for improving friction with a finger. The connecting bit

11

a

is formed as extended to be inwardly turned from forefront end of the manipulator piece

10

and to reach inside of the main shaft

3

; and the connector

11

is formed as extended rearward from the connecting bit

11

a,

at inside of the main shaft

3

. Width of the connecting bit

11

a,

which is a kind of a thicken portion for communicating between inside and outside of the main shaft

3

, is set to be slightly smaller than that of the guide slit

12

. By this manner, sliding of the connector bit

11

a

along the guide slit

12

is facilitated to enable forward and rearward moving of the manipulator piece

10

.

The connector

11

is extended rearward until meeting with the actuator piece

6

; and, meanwhile, a protrusion

15

is extended from forefront end of the connector

11

as to have length and width that are tantamount to those of the guide slit

12

. The protrusion

15

slide-wise moves within a guide slit

12

and the wide slit

14

in correspondence with slide-wise moving of the manipulator piece

10

. In particular, when the manipulator

10

is positioned at rearmost possible position, the protrusion

15

is disposed at the guide slit

12

as to conceal a perforation of the guide slit

12

; thus, preventing the perforation to be exposed to view from outside, and thereby improving ornamental effect.

The manipulator piece

10

and actuator piece

6

are integrally molded. When assembling to a writing implement, the integrally molded product is inserted from forefront opening of the main shaft

3

; and then, manipulator piece

10

is pulled out through the wide slit

14

and is mounted onto the guide slit

12

and guide groove

14

. After such inserting and mounting, a forefront shaft

5

is fixed on forefront end of the main shaft

3

to complete a writing implement

1

. At this completed state, rear fringe of the forefront shaft

5

reaches forefront of the guide slit

12

; and the forefront shaft

5

covers the wide slit

14

that is for assembling the manipulator piece

10

by pulling out the manipulator piece

10

from inside of the main shaft

3

. Thus, the wide slit

14

is not exposed to outside and no damaging of appearance is made.

Following construction of the forefront shaft

5

may also be adopted: only rear fringe portion of the forefront shaft

5

overlaps the main shaft

3

; and a slip-preventing gripper element

16

formed of elastic material is disposed at an area including the wide slit

14

, with which finger tips are to contact, as to cover the wide slit

14

; as shown in

FIG. 7

at use of the writing implement

1

.

Whereas four writing elements

4

are explained as accommodated in the above-mentioned embodiment, there may arise a following problem. Slits

12

,

14

slightly weaken shaft strength of the writing implement

1

, when the slits

12

,

14

having several millimeter widths and having ten and several millimeter lengths are disposed at center portion of the main shaft

3

having a diameter of about 12 mm. When wall thickness of the main shaft

3

is increased in view of strength, external dimension of the main shaft

3

further increases. To cope with this problem, reinforcing ribs in axial direction, which are formed of ridges with projecting dimension of slightly less than 1 mm, may be disposed between guide slits

12

on central portion of the main shaft

3

. The reinforcing ribs may be disposed to extend from forefront region having the wide slit

14

to a region having the actuator pieces

6

. Number of the writing elements

4

accommodated in the writing shaft may be not limited to four but may be three or one.

The main shaft

3

including the reinforcing ribs is to be formed as slender and elongated due to usage in a writing implement. Inside of the main shaft

3

, a supporter portion

3

a

is formed to support the actuator pieces

6

and the restoration springs

7

. Thus, a resin-molding tool is constructed to open in the fore-to-rear direction of the main shaft

3

. When the reinforcing ribs at forefront of the supporting portion

3

a

are disposed as distanced from the supporting portion

3

a

, undercut portions arise. In view of this, the reinforcing ribs are disposed to continue from the supporting portion

3

a

to the forefront region; and inner diameter of the main shaft

3

is set to slightly become larger and larger as approaching forefront in tool opening or separating-out direction. If constructed in this way, the supporting portion

3

a

acts as tool-opening line and the resin-molding tool do not become complicated due to a construction of fore-to-rear separation of the tool while preventing increase of parts or elements for the main shaft.

Assembling of the above-wise constructed writing implement

1

may be made as follows. Firstly, actuator-manipulator units each comprised of the manipulator piece

10

, the actuator piece

6

and connector

11

are inserted from forefront opening of the main shaft

3

. Then, the manipulator pieces

10

are respectively pulled out through the wide slits

14

, as to secure the actuator-manipulator units by hooking the connecting bit

11

a

on the guide slit

12

. Hereafter, refills

4

are inserted from the forefront opening of the main shaft

3

, so as rear ends of the refills

4

pass through respective through holes penetrating the actuator pieces

6

and further pass through the restoration springs

7

or coil springs to be seized by refill seizers

8

that hold the restoration springs

7

. In this way, writing elements and manipulator mechanisms are arranged on their operation positions at inside and outside of the main shaft

3

. When the forefront shaft

5

is mounted to the forefront opening of the main shaft

3

, assembling of the writing implement

1

is completed.

In hereto-mentioned embodiment, refills

4

pass through actuator pieces

6

and are supported by the refill seizers

8

on a rear cap

2

, as to secure enough length for the refills. Nevertheless, to achieve advancing and retracting action of the writing elements or refills

4

, a construction shown in

FIG. 8

may also be adopted, in which rear end portions

4

b

of the refills

4

are fitted into the actuator pieces

6

by a predetermined penetrating length; rods

9

are respectively formed at rear of the actuator pieces

6

; and spring seizers

9

a

are formed at rear ends of the rods

9

to hold the restoration springs

7

. When this structure is compared with a conventional structure of seizing the refills

4

which has refill seizers projected forward from the actuator pieces, length for the refills are longer by an extent of penetrating the rear end portions

4

b

into the actuator pieces

6

.

FIGS. 9 and 10

show another modification in respect of the essential part shown in the FIG.

3

. This modification comes under the third aspect of the invention mentioned in the summary of the invention.

FIG. 10

shows a transverse section corresponding FIG.

4

. As shown in the

FIG. 9

, traverse-sectional dimensions of the actuator pieces

6

are reduced to coincide with diameters of a bunch of the refills

4

. Arrangement for accommodating the refills

4

or writing elements is same with that shown in FIG.

1

. Nevertheless, a manner of securing the actuator pieces that advanced forward is slightly different from the arrangement of the

FIG. 1

, when writing elements or refills

4

are kept in a position for writing as in the FIG.

5

.

As evident from the

FIGS. 9 and 10

, a second projecting portion

6

c

at rear end portion of the actuator piece

6

at advanced position is not supported nor seized by a set of the first projections

6

a

′ of the other actuator pieces

6

′. The rear end portion having the second projection

6

c

is pressed to be outward in radial direction, as viewed in a transverse section of the main shaft

3

, by a set of the first projecting portions

6

a

′ of the other actuator pieces

6

. Thus, the rear end portion of the actuator piece

6

comes to bear on a shoulder

3

c

formed on inner surface of the main shaft

3

at verge of large-internal-diameter part

3

b

of the main shaft

3

. In this way, rearward moving of the actuator piece

6

at advanced position is prevented, as to facilitate writing.

Forefront end portion of the actuator piece

6

having the first projecting portion

6

a

is explained to be sector-shaped as expanded outward in a transverse section of the main shaft; nevertheless, the forefront end portion of the actuator piece

6

may be column-shaped in same diameter with the refills

4

b

. In other words, the action of outward pressing on an inner surface of the main shaft

3

may be made by pressing the rear end portion of the actuator

6

having the second projecting portion

6

c,

and subsequently moving radially outward. Therefore, the first projecting portion

6

a

may be shaped to merely take a role of bearing and supporting a rear end portion

4

b

of the refill

4

, so as the role of the forefront end portion having the first projecting portion

6

a

in the above embodiment is taken by the rear end portion

4

b

of the refill

4

.

Whereas the inner face of the main shaft

3

is illustrated as a circular cylinder in

FIG. 10

, traverse-sectional shape of the inner face may be polygonal, of star or the like. When shaped polygonal so as the wall thickness of the main shaft is varied, such thicken portions may be extended to forefront end of the main shaft to take a role of the above-mentioned reinforcing ribs.

In following, second embodiment of the invention will be described with reference to

FIGS. 11-16

.

FIG. 11

shows a longitudinal section of the writing implement, as in a same manner with the FIG.

1

. Slide-wise handling of the writing elements are made by manipulator pieces equipped at rear end of the writing implement. The push-out-type writing implement

51

of this embodiment is comprised of; a rear shaft

52

; main shaft

3

whose rear end is closed by the rear shaft

52

; four ball-point-pen refills

4

,

4

′, which are different in color with each other, and accommodated in the main shaft

3

; and a front shaft

5

that forms an opening for pushing out and retrieval of writing tip

4

a

of the refills

4

.

As shown in

FIG. 12

in detail, the rear shaft

52

is comprised of a supporting portion

58

for fitting with and closing up a rear end opening of the main shaft

3

; and a hollow cylinder extending rearward and having a rear opening provided with manipulator pieces

57

,

57

′, each of which is used for slide-wise moving respective one of the refills

4

to a position available for writing. Rear portion of the each refill

4

is secured as fitted onto a respective refill bearer

56

d

that is integrally formed with an actuator piece

6

at forefront end thereof. In rear of the each actuator piece

6

, a rod

9

is integrally formed with the actuator piece

6

, for slide-wise moving the actuator piece

6

. The each rod

9

penetrates through the supporting portion

58

and protrudes out from rear end of the main shaft

3

. A restoration spring

7

is attached on the each rod

9

.

The restoration spring

7

, which is a compression spring, constantly applies a stress on the rod

9

in a direction of pulling it rearward; and thus, in normal state, the actuator pieces

6

engaged with the refills

4

are latched as butted on a wall face of the supporting portion

58

. At rear end of the each rod

9

, cap-shaped manipulator pieces

57

are respectively disposed to cover the rod

9

and the restoration spring

7

at an area protruding from the main shaft

3

, in a decorative way.

FIGS. 13 and 14

show the writing implement

1

in a position or state readily available for writing. To reach such a writing position, the actuator pieces

6

, which is illustrated in a perspective view of

FIG. 16

, is slide-wise moved forward by pushing to slide a manipulator piece

57

on rear end of the rear shaft

52

, using one of the fingers (including a thumb); in a manner as to move the rod

9

forward against a stress of the restoration spring

7

. In this way, a refill

4

to be used is pushed out and is retracted after use; or a refill

4

of one color is changed with a refill

4

of another color for switching colors. As shown in

FIG. 16

, the actuator piece

6

is shaped as an axially elongated rod and has a first projecting portion

56

a

at forefront end thereof, which has same diameter with the rear end portion of the refill

4

.

As shown in

FIG. 15

, when four refills

4

each connected with first projecting portion

56

a

are laterally gathered together, a bunch of the four refills

4

together with the first projecting portion

56

a

has an overall periphery that is almost coincided with, and at same time slightly distanced, from the inner face of the main shaft

3

. In this way, diameter of the main shaft

3

is ultimately minimized in a multiplex writing implement. It is needless to say that a forefront part of the writing implement has a minimum clearance required for to-center-axis swerving of the refill

4

while advancing toward writing position.

As shown in

FIG. 16

, each of the actuator pieces

6

has a second projecting portion

56

b

shaped as a substantially right-angled sector expanding in radially outward, which has a circumferential face extending along an inner face of the main shaft

3

and has a sloped cam face

56

c.

The second projecting portion

56

b

is distanced rearward from the first projecting portion

56

a

by a stroke for switching the refills

4

. In original normal state as shown in

FIGS. 15 and 16

, a bunch of four of the second projecting portions

56

b,

which is gathered together in side by side manner at rear of the bunch of the four refills

4

, has an overall outer periphery shaped as a circle formed of four sector bunched together. The bunch of the second projecting portions

56

b

is kept as butted on the supporting portion

58

by action of the restoration spring

7

for pulling the rod

9

and function of the sloped cam face

56

c.

The main shaft

3

has a small-internal-diameter portion

61

formed of a ring-band shaped projection that is slightly projected from and stepped with other part of inner face of the main shaft

3

, at rear of the first projecting portion

56

a

of the actuator piece

6

that butts on the supporting portion

58

. As shown in

FIG. 15

, the internal diameter of the main shaft

3

is set as to facilitate slide-wise moving of the four refills

4

; and meanwhile, diameter of the small-internal-diameter portion

61

is set as smaller as not to allow disposing of the bunch of the first projecting portions

56

a

that are gathered side by side. When to shift to a writing position, one of the actuator pieces

6

for respective one of the refills

4

is moved forward; and then, a second projecting portion

56

c

of the one actuator piece

6

is moved to pass over the small-diameter-portion

61

, as to approach with first projecting pieces

56

a

′ of the other three actuator pieces

6

′. In this occasion, radially outward propelling force is created by function of the sloped cam face

56

c,

so as the very second projecting portion

56

c

to be disposed side by side with the first projecting portions

56

a

′ of the other actuator pieces

6

′. Then, by a stopper-bar function of a stepped portion at verge of the small-diameter-portion

61

, such writing position is kept after release of the pressing force on the manipulator piece

57

.

When one of the actuator piece

6

is moved forward by pressing a respective manipulator piece

57

as to shift one of the refills

4

to a writing position, one of first projecting portions

56

a

comes forefront of the other first projecting portions

56

a,

as to form a lateral clearance within the main shaft

3

. Then, a second projecting portion

56

b

at rear of the one first projecting portion

56

a

advances into the lateral clearance. This second projecting portion

56

a

passed through the small-diameter-portion

61

and engages with a set of the first projecting portions

56

a

′ of the other three actuators

6

′. In this occasion, the other first projecting portions

56

a

′ are pushed outwardly by function of the sloped cam face

56

c.

Consequently, when having got over the small-diameter-portion

61

, the second projecting portion

56

b

comes to be disposed side-by-side with the first projecting portions

56

a′.

After such pushing out action, if manipulating force is lifted, rearward-pulling stress of the restoration spring

7

is applied on actuator piece

6

. However, rearward moving of the actuator piece

6

is prevented by a stepped portion on verge of the small-diameter-portion

61

. Thus, refill

4

connected to the advanced actuator piece

6

is kept at a position available for writing, as shown in

FIGS. 13 and 14

. In such writing position, when one of the another actuator pieces

6

′ is moved forward, corresponding one of the first projecting pieces

56

a

comes off forward which has supported the second projecting portion

56

b

of the advanced actuator

6

for the writing-position. Thus, the second projecting portion

56

b

moves inward; or toward a central axis, and then, gets over the stepped portion on a verge of the small-diameter-portion

61

, to thereby return rearward and butts on the supporting portion

58

. If the one of another actuator pieces

6

′ thus advanced is further moved forward, a second projecting portion

56

b

of this actuator piece

6

′ gets over the small-diameter-portion

61

and comes to be disposed side by side with a set of three of the first projecting portions

56

a′.

When hand-applied force or manipulating force is lifted, a refill

4

engaged with the newly advanced actuator piece

6

′ is kept at a writing position, by herefore-mentioned mechanism.

In following, third embodiment of the invention is described with reference to

FIGS. 17-19

, and part of the FIG.

20

. In this embodiment, a writing implement

71

is a multiplex writing implement in which mechanical pencil(s) and ballpoint pen(s) are disposed as readily slidable. The writing implement may be a complex of one mechanical pencil and one ballpoint pen, a complex of mechanical pencils with different diameters of lead and one or more ballpoint pen(s), or a complex of ballpoint pen in different colors and one or more mechanical pencil(s).

At outside of a near-center portion of the main shaft

3

, manipulator pieces

10

are disposed, as shown in

FIG. 18

that illustrates a construction having actuator and manipulator pieces as in FIG.

6

. By handling of a manipulator piece

10

, an actuator piece

76

disposed inside of the main shaft

3

is moved forward and rearward to push out and retract a tip of ballpoint-pen refill

4

from a tip of a forefront shaft; thus, a writing position of the refill

4

being kept or lifted. The manipulator piece

10

is positioned at rear of the actuator piece

76

that is hooked as readily slidable on a guide slit

12

perforated on the main shaft

3

. The manipulator piece

10

is integrally connected with a connector

78

disposed in the main shaft

3

from outside to inside.

The actuator pieces

76

and connectors

78

have cylindrical hollows or are hollow cylindrical; and each refill

4

is inserted into such cylindrical hollows as to be held in them. Outside shaping of the actuator pieces

76

are rather similar with the actuator piece

6

of the second embodiment; each actuator piece

76

has a first projecting portion

76

a

at forefront, and has, at rear, a second projecting portion

76

b

having a sloped cam face

76

c

and having an external diameter slightly larger than that of the first projecting portion

76

a.

Whereas the first and second projecting portions

76

a,

76

b

have cylindrical hollows, a pair of them are integrally connected with each other by connecting strip(s)

76

e.

At forefront of the first projecting portion

76

a,

an outward-bulging stopper

74

a

is disposed on a refill

4

to prevent rearward shifting of the refill

4

relative to the actuator piece

76

. Therefore, external diameter of the first projecting portion

76

a

becomes larger than that in the second embodiment, by a dimension of thickness of the first projecting portion

76

a.

The manipulator pieces

10

butts on rear edge of the guide slit

12

and stopped. In such returned or retracted position, the first projecting portion

76

a

of the actuator piece

76

is disposed at a small-internal-diameter portion

61

in a ring-band shape, which is slightly step-wise protruding from an inner face of the main shaft

3

. Rearward stopping of the refill

4

at returned position may be made by stopping on rear part of the main shaft, as shown in

FIG. 20

, instead of the above where stopping is made by abutting rear end of the manipulator piece

10

onto rear edge of the guide slit

12

.

As in same manner with the second embodiment, the main shaft

3

has an internal diameter allowing four refills

4

to slide-wise moving; and the small-internal-diameter portion

61

has an internal diameter allowing four of the first projecting portions

76

a,

each inserted with a refill

4

, to be side-by-side wise disposed. When one of the actuator piece

76

for a refill

4

is moved forward, a second projecting portion

76

b

of the one actuator piece

76

comes close to the small-internal-diameter portion

61

. In this occasion, as shown in

FIG. 19

, the second projecting portion

76

b

engages with first projecting portions

76

a

of the other actuator pieces

76

that are inserted with refills

4

′ or a fastener-bearer portion

84

a

of a mechanical pencil

84

. After further moving forward, the second projecting portion

76

b

gets over the small-internal-diameter portion

61

; and then first projecting portion

76

′ inserted with other refill

4

′ returns rearward by action of the restoration spring

7

at rear.

After such pushing out of the refill

4

, when hand-applied force is lifted, the actuator piece

76

in advanced position undergoes rearward force. Nevertheless, the second projecting piece

76

b

in advanced position is prevented from rearward moving, by a set of first projections

76

a

′ of the other actuators

76

′, and by a stopper action of a stepped portion on verge of the small-internal-diameter portion

61

. Thus, after lifting of hand-applied force on the manipulator piece

10

, the writing position is continuously kept.

In such a writing position, it goes same manner as described earlier; with respect to restoration action of the actuator and manipulator pieces

76

,

10

by advancing the another actuator

76

′; and then, with respect to keeping the advanced refill

4

′ at writing position after further advancing the another actuator

76

.

Assembling of the writing implement

71

may be made as follows. Firstly, an integrally molded unit is prepared, which is comprised of a manipulator piece

10

, an actuator piece

76

and connector

78

; a stopper

74

a

and a spacer

79

are fitted on a refill

4

; and, into a cylindrical hollow portion of the integrally molded unit, the refill

4

is inserted until a stopper

74

a

abuts on forefront end of the actuator piece

76

, as to complete a writing unit. Thus completed writing units are inserted into a main shaft

3

from a forefront opening thereof; and the manipulator pieces

10

are pulled out to outer face of the main shaft

3

through respective guide slits

12

, as to be held in the main shaft. Naturally, the spacers

79

are moved to their illustrated position after the manipulator pieces

10

arrive on guide slits

12

.

As shown in

FIG. 20

, rear end portion of each refill

4

is inserted as to pass through a respective through hole on a supporting portion

88

disposed on rear part of the main shaft

3

, and then, inserted into a restoration spring

7

mounted on a refill bearer

8

as to abut on the refill bearer

8

. In this way, all of writing elements and manipulation mechanism are accommodated in the main shaft or held on manipulation positions on outside of the main shaft. By mounting a forefront shaft on a forefront opening of the main shaft

3

, assembling of the writing implement

71

is completed.

In following, a construction of a mechanical pencil

8

is described. In

FIG. 17

, numeral

84

a

designates a fastener-bearer formed of metal pipe or plastic pipe. Though not shown, forefront tip of the fastener-bearer

84

a

is connected with a writing element proper. Numeral

84

b

designates lead casing, which has a chuck on forefront end though not shown and is inserted into the fastener-bearer

84

a

. By clicking of the lead casing.

84

b

, a lead is gradually pushed out forward.

Rear end of the fastener-bearer

84

a

fits into a cylindrical hollow of the first and second projecting portions

86

a,

86

b

of the integrally formed actuator

86

as to be secured with each other. As rearward distanced from the actuator piece

86

by a predetermined distance, the lead casing

84

b

is fitted into and secured with a cylindrical holder

87

a

on a manipulator piece

87

that is disposed on a guide slit

12

and at outside of the main shaft

3

. Construction for holding the mechanical pencil is same with that for the ballpoint pen described earlier; in respect of shapes and dimensions of the first and second projecting portions

86

a,

86

b

of the actuator piece

86

; in respect of positional relationship between the small-internal-diameter portion

61

and the projecting portions; and in respect of dimensions of, and positional relationship between the actuator and manipulator pieces

87

.

In above manner, the lead casing

84

b

of the mechanical pencil is fitted into the holder

87

a

on a manipulator piece

10

as to be held. Thus, hand-applied force is transmitted from the lead casing

84

b

to the actuator

86

attached on a rear end portion of the fastener-bearer

84

a

; so as to facilitate pushing out of the mechanical pencil by handling the manipulator piece

10

, and as to facilitate gradual pushing out or clicking out of pencil lead by pushing and forward shifting of the lead casing

84

b.

In conventional multiplex writing implement containing a mechanical pencil usually has a problem in that force of gripping a lead is weak so as the pencil lead sinks into a writing implement under a pressure while writing, because supporting and holding is made to the lead casing itself. According to the above invention-wise construction, to contrary, force of gripping the pencil lead is made as high as that of a mechanical pencil of single use or non-multiplex type, as to eliminate the problem of the conventional multiplex writing implement. Moreover, the manipulator

87

takes a role of advancing the actuator piece

86

that is separate with the manipulator

87

and, in same time, a role of gradual forward feeding of the pencil lead by advancing the lead casing

84

b.

In the above embodiment, the actuator piece

86

is formed separate with the mechanical pencil and secured on a fastener-bearer

84

a

. Nevertheless, protrusions congruent with the first and second projecting portions

86

a,

86

b

may be integrally formed on the fastener-bearer

84

a

, as to be hooked on the small-internal-diameter portion

61

. In this occasion, across section at the protrusion in lieu of the second projecting portion is circular; thus, corresponding portion on the small-internal-diameter portion is formed to be congruent with the circular cross section as to reliably achieve supporting and hooking. By such construction, after a user has pulled out a mechanical pencil element for charging of pencil leads, reinserting of the mechanical pencil element is easily made with no care of a direction of the actuator piece.

Another embodiment will be described with reference to

FIG. 20

, which is an enlarged view showing rear end portion of a multiplex writing implement having a mechanical pencil and ballpoint-pen refills. For this embodiment, parts not shown in the

FIG. 20

may be constructed in same manner with either of the first, second and third embodiments and their modifications mentioned earlier.

A refill

4

disposed in the main shaft

3

penetrates through a supporting portion

88

and extends to a rear cap

92

closing a rear opening of the main shaft

3

. A refill bearer is

8

mounted on rear end of a restoration spring

7

deposed around the refill

4

; and the refill bearer

8

abuts on the rear cap

92

under stress applied by the restoration spring

7

. In this way, the refill

4

is held in a position.

Meanwhile, rear end of the lead casing

84

b

is fitted into and held in an open cylindrical hollow of receptacle

93

, which is disposed at rear of the rear cap

92

. A recess

94

formed on rear of the receptacle

93

holds an eraser

96

, external faces of which are enclosed by a cover

95

. The receptacle

93

is forward and rearward slidable within a predetermined length in a cylindrical hollow of the rear cap

92

, under a stress of the restoration spring

7

that is disposed between the supporting portion

88

a

of the main shaft

3

and the receptacle

93

. By such sliding motion, the lead casing

84

b

is stepwise advanced by clicking as to feed out the pencil lead from a tip of the mechanical pencil.

In an example of the above embodiment, feeding out of the pencil is made by the sliding motion of the receptacle

93

; and the advancing and retracting of the actuator piece together with the writing element is made at a manipulator piece

87

at forefront part of the main shaft

3

as in the third embodiment. Nevertheless, both of the feeding out of the pencil lead and of the advancing of the actuator may be made by the sliding motion of the receptacle

93

.

In the example of the above embodiment, the actuator piece

86

is disposed at rear end of the fastener-bearer

84

a

of the mechanical pencil; and the manipulator piece

87

is attached on the lead casing

84

b

. Nevertheless, the manipulator piece may be attached on the fastener-bearer

84

a

. Meanwhile, in respect of advancing of the ballpoint-pen refill

4

, the manipulator piece may be disposed at near of the rear end of the main shaft as in

FIGS. 3-4

, instead of disposing at near of the actuator piece

76

.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefits of priority from the prior Japanese Patent Applications No. 2001-153148 filed on May 22, 2001, and No. 2002-39275 filed on Feb. 15, 2002; the contents of which are incorporated herein by reference.

Number	Date	Country	Kind
2001-153148	May 2001	JP
2002-039275	Feb 2002	JP

Number	Name	Date	Kind
3294068	Hechtle	Dec 1966	A
5599122	Yu	Feb 1997	A
5749663	Takahashi	May 1998	A
5899618	Kobayashi et al.	May 1999	A
5927881	Yang	Jul 1999	A

Push-out-type writing implement

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (2)

US Referenced Citations (5)