JPH01221298A - Composite writing implement - Google Patents

Abstract

PURPOSE:To contrive smoother alternate protruding operations of refills, by restricting the rotating range of a rear outer tube by the engagement between a rotatable-side detent means provided on the side of the rear outer tube and a fixed-side detent means provided at a rear part of a sheath. CONSTITUTION:A rear circular stepped part of a sheath is formed to have a length equal to the lateral size of a sheath shaft part, and a stopper protrusion as a fixed-side detent for restricting the rotation and axial movements of a rear outer tube with a cam tube fixed thereto is provided at an outer peripheral part of the stepped part. On the other hand, a peripheral slide groove as a rotatable-side detent for restricting the rotation of the rear outer tube by engaging with the stopper protrusion is provided at an intermediate part of the outer peripheral surface of the cam tube. By this, when the dam tube is rotatably fitted and fastened to an engaging shaft part of the sheath, the stopper protrusion is simultaneously brought into contact with a rear end wall of the peripheral slide groove, whereby the cam tube can be rotated by 180 deg.. A detent protrusion is provided at a rear end lock part for fastening a cam-engaging protrusion on a slider when each of first and second refills is retracted, whereby forward and reverse rotations of the cam tube are restricted, and over-rotation is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a mechanical pencil with a first and a second refill, such as two types of mechanical pencils with different lead diameters, or a combination of a mechanical pencil and a ballpoint pen. The present invention relates to a composite writing instrument, and more particularly to an improvement of a composite writing instrument equipped with a slider that alternately projects first and second refills.

[Conventional technology]

Conventional composite writing instruments of this type include a sheath connected to the rear end of the front outer cylinder to which a mechanical pencil shaft and a ballpoint pen shaft are slidably attached in the axial direction; consisting of a combination of a rear outer cylinder rotatably connected to the rear end, and a cam cylinder rotatably fitted to the sheath and engaged in multiple directions around the axis within the rear outer cylinder; By rotating the rear outer cylinder, a mechanical pencil shaft and a ballpoint pen shaft are alternately projected from the tip of the front outer cylinder by means of a cam cylinder that rotates together with the rear outer cylinder.

[Problem that the invention seeks to solve]

Such conventional composite writing instruments have problems in that they have a large number of parts and a complicated structure, resulting in high costs, and that productivity is reduced because it takes a lot of time to assemble the parts.

Furthermore, when rotating the rear outer cylinder, there is a problem in that the rotation is not sufficiently prevented, causing the rear outer cylinder to rotate excessively, which may cause a failure.

This invention was made to solve the above-mentioned problems, and it reduces the number of parts, makes the entire writing instrument structure single, and reliably limits the rotation range of the rear outer cylinder. It is an object of the present invention to obtain a composite writing instrument in which the operation of alternately protruding first and second refills by rotation is smoothly and reliably performed.

[Means for solving problems]

The compound writing instrument according to the present invention regulates the rotation range of the rear outer cylinder by engaging the rotating side rotation stopper provided on the rear outer cylinder side and the fixed side rotation stopper provided on the rear part of the sheath. The configuration is such that it performs the following steps.

[Effect]

In the composite writing instrument of the present invention, when the rear outer cylinder whose rotation is restricted by the rotation prevention means is rotated in one direction, one of the first and second refills protrudes and the rear outer cylinder is rotated in the other direction. When rotated in the direction, the other of the first and second refills protrudes.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a front outer cylinder of the composite writing instrument, and a rear outer cylinder 3 is attached to the rear end of the front outer cylinder 1 via a sheath 2, and is rotatable in forward and reverse directions. Connected in a removable manner.

Incidentally, this rear outer cylinder 3 can also be slid in the axial direction so as to perform a knocking operation.

The sheath 2 is removably connected to the rear end of the front outer cylinder 1, and as a connection means, an externally threaded cylindrical part 20 at the tip of the sheath 2 is connected to an internally threaded part at the rear end of the front outer cylinder 1. The front end of the large-diameter step-shaped front circular stepped part 21 is screwed into the front outer cylinder 1 and is integrally connected coaxially with the rear end of the externally threaded cylinder part 20.
It is in contact with the rear end of. In this embodiment, the distal end of the sheath 2 and the rear end of the front outer cylinder 1 are screwed together, but they may be press-fitted or the like.

Further, here, the front circular stepped portion 21 is formed to have an outer diameter smaller than the outer diameter of the front outer cylinder 1.

That is, as shown in FIGS. 3 and 4, the sheath 2 includes, in addition to the externally threaded cylindrical portion 20 and the front circular stepped portion 21, the rear end of the front circular stepped portion 21 is coaxially connected with a K-body. It has a sheath shaft portion 22.

The sheath shaft portion 22 is formed into a rectangular flat plate having a thickness S shown in the fourth figure that is thinner than a width HK shown in the third figure.

Therefore, the axial length and radial dimension of the rear outer cylinder 3 can be shortened compared to the case where the sheath shaft part 22 is composed of a cylindrical shaft separate from the front circular stepped part 21, and the entire writing instrument can be shortened. Can be made compact.

Further, at the rear end of the sheath shaft section 22, there is a large-diameter step-shaped rear circular step section 23, and at the rear end of this rear circular step section 23, a small-diameter stepped cylindrical engagement shaft section 24 is coaxially attached. It is connected to the top.

This engagement shaft portion 24 is formed into a two-part cylindrical shape, and has a locking pawl 24a at the rear end.

As shown in FIGS. 1 and 4, the front circular stepped portion 21 has a sheath shaft that extends into the externally threaded cylindrical portion 20 at a minutely symmetrical position sandwiching the thickness of the flat sheath shaft portion 22. Two sliding holes 25 for refill insertion that open in the direction along the upper and lower surfaces of the portion 22
．． 26 are provided.

Further, as shown in FIGS. 1, 3, and 5 to 7, there is a knock on the rear end side outer peripheral surface of the front circular stepped portion 21 of the sheath 2 for regulating the forward movement of the rear outer cylinder 3. A locking protrusion 27 that functions as a stopper and restricts rotation of the rear outer cylinder 3 is integrally provided.

As a means for regulating the forward movement and rotation of the rear outer cylinder 3, as shown in FIGS. A groove 30 is formed.

The circumferential sliding groove 30 is formed in a substantially semicircular arc shape so that the locking protrusion 21 can be rotated in the forward and reverse directions by 180 degrees. An axial slide @30a is connected to one end.

This axial sliding groove 30a is connected to a mechanical pencil shaft 4 which will be described later.
As shown in FIGS. 1 and 6, between the rear end of this axial sliding groove 30a and the rear end of the locking protrusion 27, there is a Knocking allowance at the end (b)
Knock length (a) equal to or longer than
A distance is provided.

Therefore, the axial sliding groove 30a comes into contact with the rear end of the locking protrusion 27 at the forward knocking position of the rear outer cylinder 3, thereby restricting the forward movement of the rear outer cylinder 3.

In this embodiment, the axial sliding groove 30a is provided only at one end of the circumferential sliding groove 30.

This is because it is not necessary to knock the ballpoint pen shaft 5, which will be described later, so that only the mechanical pencil shaft 4 can be knocked.

However, when both the first and second refills are mechanical pencil shafts, both need to be capable of knocking, so as shown in FIG. 30a and 30b may be connected and formed.

As shown in the first diagram, a mechanical pencil shaft (first refill) 4 and a ballpoint pen shaft (second refill) 5 each slide in the sliding holes 25 and 26 of the sheath 2 in the axial direction. Possibly inserted.

The mechanical pencil shaft 4 has a lead guide 41 detachably connected to the tip of the lead pipe 40 inserted into one of the sliding holes 25, so that the rear outer cylinder 3 can be removed from the front outer cylinder 1. After removing the sheath 2 from the front outer cylinder 1, the core pipe 40 can be refilled by pulling out the core pipe 40 from the lead guide 41.

In this mechanical pencil shaft 4, a lead feeding mechanism 42 is arranged on the distal end side of the lead guide 41. The lead delivery mechanism 42 includes a lead chuck, a chuck tightening ring, and a first elastic body 43 (not shown).

On the other hand, the ballpoint pen shaft 5 is detachably connected to the front end of a pen mounting shaft 50 that is slidably inserted into the other sliding hole 26 . The ballpoint pen shaft 5 may be connected to the front end of a pen mounting shaft 50 via a pen holder 51, as shown in FIG. In this case, the pen holder 51 includes a small-diameter shaft portion 50a at the tip end of the pen mounting shaft 50 and a connecting cylinder portion 51A having the smallest diameter, which is connected by press-fitting, adhesive, etc. A large-diameter step-like small-diameter fitting tube portion 51B into which the core pipe 40 can be fitted and connected; and a large-diameter step-like large-diameter fitting tube portion 51B communicating with this tip to which the rear end side of the ballpoint pen shaft 5 is removably connected. It has a structure consisting of a joint tube portion 51C.

With this pen holder 51, its large diameter fitting cylinder portion 51C
By removing the ballpoint pen shaft 5 that has been fitted and connected to the mechanical pencil shaft 4 and fitting and connecting another mechanical pencil shaft with a different core diameter or type from the mechanical pencil shaft 4 to the small diameter fitting tube portion 51B, refill compatibility can be achieved. You can get sex.

Sliders 6.7 are integrally connected to the rear ends of the mechanical pencil shaft 4 and the ballpoint pen shaft 5, respectively.

As shown in FIG. 9, the slider 6.7 consists of a symmetrical semicircular member, and an axial sliding groove 60.70 is provided on the flat surface on the center side of each arc.

These axial sliding grooves 60 and 70 are formed to have a groove width corresponding to the width H of the sheath shaft 22, and are fitted into the sheath shaft 22 from above and below, so that the sheath shaft 22 can be held in place. They can be slid individually in the axial direction.

Therefore, each of the side walls of the axial sliding grooves 60 and 70 includes a hook leg portion 60a that is slidable in the axial direction on both side surfaces of the sheath shaft portion 22 and is secured in the axial direction. 60a
and 70a, 70a are formed.

Here, the slider 6.7 has the axial sliding groove 60.
The bottom surface of 70 is in surface contact with the upper and lower flat surfaces of the sheath shaft portion 22, and the above-mentioned hook leg portion 60a
JOa and 70a, 70a engage with the side surface of the sheath shaft portion 22, so the slider 6°7 engages with the side surface of the sheath shaft portion 22.
2. It can slide stably and smoothly without coming off.

In addition, at the center of the outer peripheral surface of each of the sliders 6.7, the rear end is pressed against the cam surface of a cam cylinder 8, which will be described later, as shown in FIGS. Cam engagement protrusion 61 for engaging and pushing the slider 6.7 forward
．． 71 is integrally provided.

The rear end portion of each cam engaging protrusion 61, 71 is formed into a sharp tapered shape as shown in FIGS. 2 and 10, or a circular shape (not shown).

The mechanical pencil shaft 4 and the ballpoint pen shaft 5 are always moved backward by elastic bodies 44 and 52 interposed between the rear end of the front circular stepped portion 21 of the sheath 2 and the front ends of the sliders 6.7. energized.

This allows the cam engagement protrusion 61. of each slider 6.7.
The rear end of γ1 is pressed into engagement with the cam surface of the cam cylinder 8.

At the rear end side of the sheath shaft portion 22 of the sheath 2, in which the mechanical pencil shaft 4 and the ballpoint pen shaft 5 are attached as a unit, there is a cam tube 8 for causing the mechanical pencil shaft 4 and the ballpoint pen shaft 5 to alternately protrude. are fitted and engaged so that they can rotate forward and backward.

That is, by inserting and passing the locking pawl 24a of the engagement shaft portion 24 at the rear end of the sheath shaft portion 22 from the front end side into the small diameter shaft insertion hole 80 provided at the rear end side shaft center of the cam cylinder 8, This locking pawl 24a is a button that engages with the rear end wall surface of the shaft insertion hole 80 so that the cam cylinder 8 can rotate around the engagement shaft portion 24.

Here, as shown in the first figure, in a state where the rear end wall surface of the shaft insertion hole 80 is engaged with the locking pawl 24a, the rear end surface of the sheath shaft portion 22 and the front end wall surface of the shaft insertion hole 8° A distance can is provided between the two.

This distance (b) serves as a knock for feeding out the lead of the mechanical pencil shaft 4, and is equal to the distance (a) above, or
It is formed to a length equivalent to that length.

Therefore, the cam cylinder 8 can move forward in the axial direction by the distance (b), thereby enabling knocking.

Further, the cam cylinder 8 is engaged with the rear outer cylinder 3 in the axial direction.

As the engagement means, an axial locking groove 81 (see FIGS. 1 and 11 to 13) provided on the outer circumferential surface of the rear end of the cam cylinder 8
A detent projection 31 (see FIGS. 1 and 13) integrally protruding from the inner circumferential surface of the rear end of the rear outer cylinder 3 is fitted and engaged with the rear outer cylinder 3 (see FIG. 1).

This allows the cam cylinder 8 to rotate integrally with the rear outer cylinder 3.

An internal threaded portion 8 provided on the rear end side of the cam cylinder 8
2 is screwed with an externally threaded cylindrical portion 90 of the top vista. At the time of screwing, the plunge shaft portion 93 integrally protruding from the shaft center of the crown screw 9 is inserted into the engagement shaft portion 24, thereby press-contacting the locking pawl 24a against the shaft insertion hole 8o. This makes the engagement even more reliable and firm.

Further, in the top vista, the base of the chryso 7'' 100 is collinear with the rear end of the rear outer cylinder 3.

The cam cylinder 8 is shown in FIGS.
2. As shown in Figure 2, curved inclined cam surfaces 83.8 on both sides of the front end.
4, a tip locking portion 85 provided at the most extreme end of these curved inclined cam surfaces 83.84, and the curved inclined cam surfaces 83.
84 and a rear end engaging portion 86.

When the slider 6.7 is retracted into the front outer cylinder 1, the cam engaging protrusion 61 of the slider 6 of the mechanical pencil shaft 4 is on one curved inclined cam surface 83, and the cam engaging protrusion 61 of the slider 6 of the mechanical pencil shaft 4 is The slider T of the ballpoint pen shaft 5 is attached to the curved inclined cam surface 84.
The cam engaging protrusions 71 are pressed and engaged by the biasing force of the elastic bodies 44 and 52, respectively.

Therefore, as shown in FIGS. 2 and 14, when the cam barrel 8 rotates and the cam engaging protrusion 61.71 is held at the intermediate portion of the curved inclined cam surface 83.84, the mechanical pencil shaft 4
The ballpoint pen shaft 5 is housed and held in the retracted position within the front outer cylinder 1. Furthermore, when the cam engagement protrusion 61 of the mechanical pencil shaft 4 engages with the front end locking portion 85, the mechanical pencil shaft 4 protrudes, and at the same time, the cam engagement projection 71 of the ballpoint pen shaft 5 engages with the rear end locking portion 86. Thus, the ballpoint pen shaft 5 is held in the retracted storage position. Conversely, when the cam engaging projection 61 on the mechanical pencil shaft 4 side engages with the rear end engaging portion 86 and the cam engaging projection 71 on the ballpoint pen shaft 5 side engages with the tip engaging portion 85, the mechanical pencil shaft 4 The ballpoint pen shaft 5 is held at the stored position and at the protruding position.

In this manner, the rotation of the cam barrel 8 causes the mechanical pencil shaft 4 and the ballpoint pen shaft 5 to advance alternately and to be retracted at the same time.

Next, the operation of the above embodiment will be explained. When the rear outer cylinder 3 is rotated in one direction, the cam cylinder 8 integrally engages the cam engaging protrusion 61 of the 6 with one curved inclined cam surface 83 as shown in FIG.
is moved forward toward the tip locking portion 85 side. At this time,
The slider 6 is subjected to the rotational load of the cam cylinder 8, but this load is caused by the hooking legs 60a, 60a of the slider 6 engaging with both sides of the sheath shaft 22, as shown in FIG. Therefore, the above slider 6
slides smoothly forward along the sheath shaft portion 22.

As a result, the mechanical pencil shaft 4 moves forward.

At the same time, the cam engaging protrusion 71 of the slider 7 of the ballpoint pen shaft 5 engages the other curved inclined cam surface 84 in the rear end locking portion 8.
6, the ballpoint pen shaft 5 moves backward. This backward movement is performed by the urging force of the elastic body 52.

Then, the cam engagement protrusion 61 on the mechanical pencil shaft 4 side engages with the tip locking portion 85, and the cam engagement protrusion 71 on the ballpoint pen shaft 5 side engages with the rear end locking portion 86. The mechanical pencil shaft 4 is held at a position protruding from the tip of the front outer cylinder 1, and at the same time, the ballpoint pen shaft 5 is housed and held at a retracted position within the front outer cylinder 1.

In this state, when the rear outer cylinder 3 is knocked, the cam cylinder 8 moves forward together with the rear outer cylinder 3, and the slider 6 of the mechanical pencil shaft 4 moves forward with the cam cylinder 8, which causes the lead pipe to move forward. 40 is pushed forward and the core feeding mechanism 42 operates to perform core feeding.

When the rear outer cylinder 3 is rotated in the other direction from this state, the cam W8 integrated therewith is rotated in the other direction, and the mechanical pencil shaft 4 moves along one curved inclined cam surface 83 of the cam cylinder 8. At the same time that the cam engaging protrusion 61 on the side moves backward, the cam engaging protrusion 71 on the ballpoint pen shaft 5 side is moved forward by the other curved inclined cam surface 84 of the cam barrel 8.

As a result, the ballpoint pen shaft 5 moves forward and protrudes, and at the same time, the cam engaging protrusion 71 engages with the tip locking portion 85 to be held at that position, and at the same time, the mechanical pencil shaft 4 retreats and is stored. Ru.

FIG. 15 shows another embodiment of the slider 6.7. In this embodiment, by removing one of the hook legs 60a and 70a of each of the sliders 6 and 7 shown in FIG. Sections 60a and 70a are provided.

In this case, the hook leg portions 60a e 70a absorb the rotational load of the cam barrel 8 when the cam barrel 8 rotates in the forward direction of the mechanical pencil shaft 4 (rotation in the direction of arrow (A) in FIG. 115). The hook leg 60a of the slider 6 on the side of the mechanical pencil shaft 4
is engaged with one side of the sheath shaft portion 22, and the ballpoint pen shaft 5
When the cam barrel 8 rotates in the forward direction (rotation in the direction of arrow (B)), the rotational load of the cam barrel 8 causes the ballpoint pen shaft 5 to
The hook legs 70a of the side sliders 7 are provided on each side of each of the sliders 6.7 so as to engage with the other side of the sheath shaft 22.

As a result, when the mechanical pencil shaft 4 and the ballpoint pen shaft 5 move forward, the rotational load of the cam cylinder 8 causes the above-mentioned hook leg portion 60 to
Since the sliders 6 and 70a alternately engage with the side surfaces of the sheath shaft portion 22, the sliders 6 and 7 do not come off from the sheath shaft portion 22 due to the rotational load of the cam cylinder 8, and the sliders 6.7 As in the case of the example, the sheath shaft portion 22 is stably and smoothly slid forward.

16 to 18 and 19 to 21 show embodiments of a rotation restriction mechanism, which is a main part of the present invention, which restricts the rotation range of the rear outer cylinder 3 to which a cam cylinder is fixed. In this second embodiment, the sheath 2 and the cam barrel 8 are each improved.

First, the structure of the sheath 2 will be explained with reference to FIGS. 16 to 18.

The rear circular stepped portion 23 of the sheath 2 is formed to have a length equal to the width H of the sheath shaft portion 22, and a cam # is formed on the outer periphery of the rear circular stepped portion 23.
A stopper protrusion 28 serves as a fixed-side rotation stopper for regulating the rotation and axial movement of the rear outer cylinder 3 to which 8 is fixed.
It is integrally installed.

On the other hand, the structure of the cam cylinder 8 will be explained with reference to FIGS. 19 to 22.

A circumferential sliding groove 87 is provided in the middle of the outer circumferential surface of the cam cylinder 8 to engage with the stopper protrusion 28 and serve as rotation stopping means for restricting the rotation of the cam cylinder 8 and, in turn, the rear outer cylinder 3. There is.

This circumferential sliding groove @87 is formed in a semicircular shape over the half circumferential surface of the cam cylinder 8 on the maximum axis length side, and one end of the circumferential sliding groove 87 has a knock securing groove extending rearward. The front end of the axial sliding groove 88 is connected.

The distance (c) between the rear end of the axial sliding groove 88 and the rear end of the stopper protrusion 28 is equal to or greater than the distances (, ) and (b) shown in the first diagram, as shown in FIG. 22. It is formed to a corresponding length.

Further, a guide 1118g extending axially forward is provided in the middle of the axial sliding groove 88 to facilitate assembly of the cam cylinder 8 to the sheath 2.

The stopper protrusion 28 of the sheath 2 is fitted into the guide groove 89 from the inside when the sheath 2 is inserted into the shaft insertion hole 80 of the cam cylinder '8.

That is, by inserting and passing the locking claw 24a of the sheath 2 into the shaft insertion hole 80 with the stopper protrusion 28 fitted into the guide groove 89 from the inside, the cam cylinder 8 engages the engaging portion 24 of the sheath 2. It is fitted and locked so that it can rotate freely. At the same time, the stopper protrusion 28 comes into contact with the rear end wall of the circumferential sliding groove 8γ, and slides within the circumferential sliding groove 81 by the rotation of the cam cylinder 8, thereby causing the cam cylinder 8 can be rotated by 180 degrees. Therefore, the axial engagement between the stop projection 31 of the rear outer cylinder 3 and the cam cylinder 8 in FIG.
1 is unnecessary), these can be removed.

Furthermore, when the stopper protrusion 28 engages with one end of the circumferential sliding groove 87 on the axial sliding groove 88 side, the stopper protrusion 28 becomes able to slide within the axial sliding groove 88. This allows the cam 8 to move forward when the mechanical pencil shaft 4 is knocked to feed out the lead.

Therefore, in this embodiment, the cam cylinder 8 is integrated with the rear outer cylinder 3.
When the stopper protrusion 28 of the sheath 2 engages with one end of the circumferential sliding groove 81 of the cam cylinder 8 by rotating in one direction, the unidirectional rotation of the cam cylinder 8 is restricted, and the front portion At the same time that the mechanical pencil shaft 4 protrudes from the tip of the outer cylinder 1, the ballpoint pen shaft 5 is stored in the retracted position within the front external cylinder 1.

In this state, when the rear outer cylinder 3 is knocked, the cam cylinder 8 moves forward together with the rear outer cylinder 3. In this case, the stopper protrusion 28 is inserted into the axial sliding groove 8 of the cam cylinder 8.
By moving backward within the cam cylinder 8, the cam cylinder 8 is allowed to move forward. When the lead pipe 4o of the mechanical pencil shaft 4 is pushed forward by the cam cylinder 8, the lead delivery mechanism 42 is operated to perform lead feeding.

When the knock of the rear outer cylinder 3 is released, the cam cylinder 8 moves backward by the elastic force of the elastic body 44, 52, and the stopper protrusion 28 engages with the front end of the axial sliding groove 88, causing the cam cylinder 8 to move backward due to the elastic force of the elastic body 44. It is held in a slidable state within the directional sliding groove 87.

When the rear outer cylinder 3 is rotated in the other direction from this state, the cam cylinder 8 is rotated in the other direction together with the rear outer cylinder 3, and the stopper protrusion 28 slides in the circumferential sliding groove 81 in the other direction. As the ballpoint pen shaft 4 moves, the cam engaging protrusion 61 of the slider 6 of the ballpoint pen shaft 4 moves one curved inclined cam surface 83 from the tip locking portion 85 to the rear end locking portion 86, and the ballpoint pen shaft 5 moves in the opposite direction. The cam engaging protrusion T1 of the slider 7 moves on the other curved inclined cam surface 84.

As a result, the ballpoint pen shaft 5 protrudes and the mechanical pencil shaft 4 is retracted and stored, and at the same time, the stopper protrusion 28 engages with the other end of the circumferential sliding groove 87 at that position, and the cam barrel 8 is restricted from rotating in the other direction.

FIG. 23 shows a second embodiment of a rotation regulating mechanism for regulating the rotation of the rear outer cylinder 3, which is the essential part of the present invention.

In this embodiment, first mechanical pencil shafts 4 having different lead diameters are used.
and the second mechanical pencil shaft 5 are alternately projected by a cam barrel 8.

That is, in order to obtain knocks for lead feeding at the respective protruding positions of the first and second mechanical pencil shafts 4 and 5, axial sliding grooves are provided at both ends of the circumferential sliding groove 8T, which serves as a rotation stopper. The moving grooves 88 and 88a are connected.

Therefore, when the cam barrel 8 is rotated in one direction together with the rear outer barrel 3, the cam engaging protrusion 61 of the slider 6 of the first mechanical pencil shaft 4 locks the tip of one curved inclined cam surface 83. At the same time, the cam engaging protrusion 71 of the other mechanical pencil shaft 5 system engages the other curved inclined cam surface 84.
By moving toward the rear end locking portion 86, the first mechanical pencil shaft 4 moves forward, and the second mechanical pencil shaft 5 moves backward.

Then, by engaging the stopper protrusion 28 as a movable rotation stopper with one end of the circumferential sliding groove 87,
The unidirectional rotation of the cam cylinder 8 is restricted, and at the same time the first mechanical pencil shaft 4 protrudes from the tip of the front outer cylinder 1, the second mechanical pencil shaft 5 retracts within the front external cylinder 1. stored in position.

In this state, by knocking the rear outer cylinder 3, the cam cylinder 8
When the mechanical pencil shaft 4 moves forward, the lead of the first mechanical pencil shaft 4 is fed.

Next, when the cam barrel 8 is rotated in the other direction, the first mechanical pencil shaft 4 retreats and the second mechanical pencil shaft 5 advances and protrudes, and the subsequent knocking action causes the cam barrel to move backward. 8 moves forward, the lead of the second mechanical pencil shaft 5 is fed.

In this manner, the first and second mechanical pencil shafts 4.5 are caused to protrude from each other by the forward and reverse rotation of the cam cylinder 8 by the rear outer cylinder 3.

When the cam barrel 8 rotates in one direction, one of the first and second mechanical pencil shafts 4 protrudes and the other retracts, and the stopper protrusion 28 engages with one end of the circumferential sliding groove 87. By doing so, the unidirectional rotation of the cam cylinder 8 is restricted.

Further, due to the rotation of the cam barrel 8 in the other direction, the rotation of the cam barrel 8 in the other direction is restricted at a position where one of the mechanical pencil shafts 4.5 is retracted and the other protrudes.

When the cam barrel 8 is further rotated approximately 90 degrees, the cam engaging protrusions 61.71 of the sliders 6.7 of the first and second mechanical pencil shafts 4.5 engage the curved inclined cams on both sides of the cam barrel 8. It is held in the middle of each of the surfaces 83,84. As a result, the first and second mechanical pencil shafts 4.5 are each held in the storage position within the front outer cylinder 1.

FIGS. 24 to 29 show a third embodiment of the rotation regulating mechanism which is the main part of the present invention. In this embodiment, as a rotation restricting means of the rear outer cylinder 3 to which the cam cylinder 8 is fixed, a rotation prevention protrusion 80a as a rotation side rotation prevention means protruding from the inner circumferential surface of the cam cylinder 8; This is achieved by engagement with an engagement groove 23a, which is formed on the sheath 2 and serves as a stationary side rotation preventing means.

That is, a detent projection 80a is provided on the inner peripheral surface of the cam cylinder 8 and protrudes from the front end side of the shaft insertion hole 80.

In addition, 8a is the locking groove 3a of the rear outer cylinder 3, as described later.
This is a locking protrusion that engages with the cam cylinder 8 and rotates the rear outer cylinder 3 integrally.

On the other hand, on the outer circumferential surface of the rear circular stepped portion 23 of the sheath 2, as shown in FIGS. 25 to 27, there is a cutout engagement groove 23a that engages with the rotation prevention protrusion 80a and restricts its rotation range. It is formed.

The notch engagement groove 23a allows the rotation prevention protrusion 80a to
It is formed into a substantially semicircular arc shape that can be rotated forward and backward by 80 degrees.

The cam cylinder 8 is attached to the inner circumferential surface of the rear outer cylinder 3.
The directions are engaged so that the rear outer cylinder 3 and the rear outer cylinder 3 rotate in the forward and reverse directions.

As the engagement means, as described above, the locking protrusion 8a provided on the outer peripheral surface of the rear end side of the cam cylinder 8 is fitted and engaged with the locking groove 3aK provided on the inner peripheral surface of the rear outer cylinder 3. There is. In contrast to this embodiment, a locking groove may be provided on the outer peripheral surface of the rear end of the cam cylinder 8, and a locking protrusion may be provided on the inner peripheral surface of the rear outer cylinder 3.

FIGS. 30 and 31 show a fourth embodiment of the rotation regulating mechanism, which is the main part of the present invention. In this embodiment, the rotation restricting means for the rear outer cylinder 3 is different from that in the third embodiment, and a rotation preventing protrusion 80a is provided as a means for preventing the number of rotations υ provided protruding from the inner circumferential surface of the cam cylinder 8. This is done by engagement with the cam engagement protrusion 61.71 of the slider 6.7.

Therefore, the rear circular step 2 of the sheath 2 is different from the third embodiment.
No. 3 engagement groove 23a is required.

That is, in this embodiment, as shown in FIG. 30, a detent projection 80 is provided on the rear end locking portion that locks the cam engaging projection 61.71 of the slider 6° 1 when the reflex wheel 4.5 is retracted.
a is formed.

Therefore, in this fourth embodiment, the anti-rotation protrusion 80a engages with the cam engagement protrusion 61t or 71, restricts the forward and reverse rotation of the cam cylinder 8, and prevents the cam cylinder 8 from rotating too much. . still,
This embodiment also ensures a knock (b) between the cam engaging protrusion 61 or 11 and the rear end engaging portion 86, and the first. Either one of the second refills 4.5 (in this case, the third refill)
The reference numeral 86 in FIGS. 0 and 31 is formed as indicated by a dotted line. ) or both (in this case, the reference numeral 86 in the above figure is indicated by a solid line) can be knocked.

32 to 34 show other embodiments of the connection structure between the front outer cylinder 1 and the sheath 2. In this embodiment, a small-diameter step-shaped cylindrical portion 22A is provided at the front end side of the front circular stepped portion 21 of the sheath 2, and this cylindrical portion 22A is formed to have an outer diameter equal to the inner diameter of the front outer cylinder 1. A plurality of locking protrusions 228 are integrally provided on the outer peripheral surface of the portion 22A.

Further, on the rear end side of the front outer cylinder 1, as shown in Fig. 33,
An axial guide hole 11 into which the locking protrusion 228 is introduced from the rear end, and a circumferential lock which communicates with the front end of the axial guide hole 11 and introduces the locking protrusion 228 from the outer cylinder axial guide hole 11. A hole 12 is provided.

On the entrance side of the circumferential locking hole 12, a locking step 13 is provided.
An elastic locking piece 14 which is inclined on the opposite side is provided.

Therefore, when the locking projection 228 is pushed into the axial guide hole 11 from the rear end and the sheath 2 is rotated in one direction, the locking projection 228 is pushed into the circumferential locking hole 12.
And, due to the elastic force of the elastic locking piece 14, the locking step portion 13
It is press-fitted and locked inside.

Thereby, the sheath 2 can be detachably connected to the front outer cylinder 1 with one touch. The other configurations of this embodiment are the same as those of the first embodiment. Therefore, the same effects as in the first embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the rear outer cylinder can be securely moved by the engagement between the rotating side rotation preventing means provided on the rear outer cylinder side and the fixed side rotation preventing means provided on the rear part of the sheath. Moreover, there is an effect that smooth rotation regulation can be achieved.

Claims (3)

[Claims] (1) A sheath (2) detachably connected to the rear part of the front outer cylinder (1) and having the first and second refills (4) and (5) attached so as to be slidable in the axial direction; , first and second sliders connected to the rear portions of the first and second refills (4) and (5), respectively, and inserted into the rear outer cylinder (3) so as to be slidable in the axial direction. 6), (7) and
It is provided on the rear outer cylinder (3) side, and presses and engages at least one of the first and second sliders (6) and (7) when the refill is projected, and when the rear outer cylinder (3) rotates, , pressing protrusion means (34) for alternately protruding the first refill (4) and the second refill (5);
and a rotation restriction mechanism that restricts rotation of the rear outer cylinder (3), and the rotation restriction mechanism includes a rotation side detent means (87) formed on the rear outer cylinder (3) side. , 80a) and
A stationary side detent means (28, 23a) A composite writing instrument characterized by comprising: (2) The compound according to claim 1, characterized in that the rotation side detent means (87, 80a) is formed of a detent protrusion protruding from the rear outer cylinder (3) side. Writing implements. (3) The rotation side detent means (87, 80a) include:
The fixed side rotation preventing means (28, 23a) is capable of knocking.
3. The composite writing instrument according to claim 1, wherein grooves (88, 88a) are formed in which the writing instrument is slidable in the axial direction.