JPH08175081A - Dual writing instrument - Google Patents

Abstract

PURPOSE: To omit a predetermined number of components with a resin instead of a metal, to simplify the structure and to reduce the cost by extending a rear shaft integrally at the rear of a cylindrical cam, inserting a coiled spring fixed to a head crown in the shaft, and so fastening the crown as to be only rotated only with respect to the shaft. CONSTITUTION: A slightly protruding protrusion 37a out of the rear end of a coiled spring 37 is engaged with the slit 38 of the inner cylinder 35 of a head crown, locked by a stopper 38a, and the spring 37 is fixed integrally with the front side of the crown. The protrusion 41 of an eraser holder 40 fastened with an eraser 44 is engaged with the rear end of the spiral part of the spring 37 to be inserted, and the holder 40 is so guided as to be only movable with respect to a rear shaft 4. When the outer cylindrical part 34a of the crown is rotated with respect to the shaft 4, the holder 40 is moved longitudinally so that the eraser 44 is telescopic from the rear end hole 39 of the crown.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple writing instrument in which the tips of a plurality of writing bodies can be alternately retracted and retracted at the tip of the front shaft, and an eraser can be retracted and retracted from the rear end of the rear shaft.

[0002]

2. Description of the Related Art Heretofore, as an example of a compound writing instrument, as shown in Japanese Utility Model Application Laid-Open No. 64-3491 by the same applicant, a sliding groove for guiding two writing instruments is provided on the leading shaft. The front end has a guide cylinder fixed to the guide cylinder and a cam slope contacting the sliding pieces attached to the two cursive bodies fitted to the guide cylinder. It is equipped with a cylindrical cam that is movable in the axial direction and is integrally rotated in the circumferential direction.By rotating the cap with respect to the tip shaft, the two cursive writing bodies are selectively moved at the tip end opening of the tip shaft. There are multiple writing instruments that can appear and disappear.
Further, as a cited example of the present application, there is a compound writing instrument in which an eraser is projected and retracted by rotating a crown protruding from a rear end of a cap, as seen in Japanese Utility Model Laid-Open No. 60-120889. .

[0003]

The above cited examples have the problems that metal parts are used in many parts, the structure is complicated, the number of parts is large, and the cost is high.

[0004]

SUMMARY OF THE INVENTION A multiple writing instrument of the present invention devised to solve the above-mentioned problems is designed such that a tip of a resin-made front shaft and a tip of a resin-made center shaft are fitted in a non-rotatable and retaining state. The engaging parts to be worn must be provided and fixed to each other. A guide part integrated with the center shaft and a substantially L-shaped window part in which a vertical groove and a peripheral groove are connected to each other through a narrow part are bored on the rear side surface of the center shaft,
A plurality of writing bodies with at least one sliding pencil fixed to the rear end in a plurality of guide grooves provided in the guide tube, which is a mechanical pencil writing body, are movably fitted back and forth through return springs, respectively. A projection is provided on the side surface of the cylindrical cam that has a circumferentially-displaced cam slope that is displaced in the direction, and the projection is elastically fitted into the circumferential groove to allow the cylindrical cam to move within a certain range with respect to the guide and the center shaft. Prevents slippage so that rotation and axis transition are possible,
Only by selecting the mechanical pencil, the tip of each cursive body can be selectively retracted from the tip opening of the tip by alternately moving each sliding piece in the front-back direction by rotating the cylindrical cam with respect to the tip axis or the center axis. The cylindrical cam moves along the axis to extend the core. In addition, a rear shaft is integrally provided behind the cylindrical cam, and a resin crown is rotatably attached to the rear end of the rear shaft, and a coil spring is fixed to the tip of the crown to stop the eraser. The attached eraser holder engages the protrusion with the spiral part of the coil spring and is guided so that it can only move axially with respect to the rear shaft.By rotating the rear shaft with respect to the front shaft or the center shaft, the tip of the writing body appears and disappears. The eraser can be retracted by rotating the crown with respect to the rear shaft.
As described above, the compound writing instrument according to the present invention has a simple structure because the number of parts is omitted, and the assembly is easy. Further, since the spiral groove, which is formed on the upper surface of the molding or die manufacturing process, becomes a coil spring which can be easily processed, the cost can be reduced. In addition, according to the embodiments described later, since the projection of the cylindrical cam does not contact the front wall of the circumferential groove even if a drop impact is applied to the rear end of the rear shaft, there is also an effect of preventing breakage of the projection or the like.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, FIGS. 1 and 3 show a first embodiment of the present invention. The compound writing instrument of the present invention includes a center shaft 1 integrally provided with a guide portion 2, a front shaft 3, a rear shaft 4 integrally provided with a cylindrical cam 5, a sliding piece 6, a 6-pencil pencil writing body 7, a writing body such as a ballpoint pen. 8, crown 34, eraser holder 4
0 and eraser 44 are the main constituent elements. First, the central shaft 1
Is made of resin, and as shown in FIG. 1, there is a guide groove 9 that is long in the axial direction and opens in the side surface from the substantially central portion to the rear end, and a guide portion 2 that has a similar guide groove 9 ″ on the side surface opposite to it. It is provided. The front half of the guide portion 2 is provided with a tubular portion 10 having a partition portion 16 communicating with the guide grooves 9 and 9 ′ and having holes 32 and 32 ′ and having a front end opened. A step portion 31 is provided at an end, and a bulging engagement portion 13 is formed on a front outer peripheral portion of the step portion 31.

Further, as shown in FIG. 2, on the rear side surface of the center shaft 1, the vertical groove 18 is connected to the circumferential groove 19 through the narrow inclined portion 45 and the narrow groove portion 46 is connected to the circumferential groove 19. Has been drilled. Further, as will be described later, the protrusion 17 of the cylindrical cam 5 is inserted from the vertical groove 18, and the protrusion 17 elastically expands the inclined surface 45, passes through the narrow portion 46, and enters the circumferential groove 19. The cylindrical cam 5 rotates while the projection 17 abuts on the circumferential rear wall of the circumferential groove 19 so that the writing parts of the mechanical pencil writing body 7 or the writing body 8 such as a ball-point pen are alternately projected and retracted from the leading end of the leading shaft. Become. Further, the circumferential groove 19 is provided with a wide groove 47 so that the cylindrical cam 5 can be axially moved at the position of the projection 17 when the mechanical pencil writing body 7 projects, and when the writing body is stored or the writing body 8 such as a ballpoint pen is used. The rear wall 49 of the circumferential groove 19 is arranged so that the cylindrical cam 5 cannot substantially move along the axis at the position of the protrusion 17 when protruding.
An inclined surface 49b is connected between a and the rear wall 49c to form a narrow groove 48. Further, as will be described later, the wall 20 of the rear shaft 4 comes into contact with the rear end of the center shaft 1 at the front end of the axial transition, and the projection 17
Is set so that the front end thereof does not contact the front wall 49d of the circumferential groove 19.

The front end of the front shaft 3 is tapered, and the front end of the inner hole is provided with an inner step portion 27. Further, the rear end hole is provided with an engaging groove 12 which is engaged with an engaging portion 13 provided on the outer peripheral portion of the tubular portion 10 of the guide tube and which prevents the tubular portion 10 from coming off and rotation. . The cylindrical portion 10 and the tip shaft 3 are detachably fixed with an appropriate force. (Actual development 6
(Same as the configuration of the front shaft in the publication of 4-3491)

The rear shaft 4 is made of resin, and has a circumferential wall 20 for axially supporting the cylindrical cam 5 formed in the inner hole of the front side. Further, in the rear of the outer peripheral portion, a protruding engagement portion 33 is provided on the shaft portion 4b having a slightly smaller diameter.
Are formed. The cylindrical cam 5 has a tubular shape, has a cam slope 14 that is circumferentially displaced forward and backward at the front edge, and a notch 15 is formed at the forefront end of the cam slope 14. Further, on the side surface of the cylindrical cam 5, the cylindrical cam 5 is inserted into the vertical groove 18 of the center shaft 1 and elastically fitted into the circumferential groove 19 so as to have a predetermined range (approximately 180).
The protrusion 17 is formed so as to rotate and prevent it from coming off.

By the way, the cylindrical cam 5 has a cylindrical portion 36 extending rearward, and a long slit portion 36a is formed behind the stepped portion 36b. On the other hand, the resin crown 34 has an outer cylinder portion 34a formed at the rear side thereof, and an inner cylinder portion 35 provided inwardly toward the front thereof, and the slit portion 38 and the slit 38 are provided on one side of the inner cylinder portion 35. An inwardly projecting stopper 38a is provided at an appropriate position. Also, the outer cylinder portion 34a
An engaging portion 34b having a circumferential groove is formed on the inner surface of the.

By the way, a projection 37a slightly protruding outward from the rear end of the coil spring 37 is fitted in the slit portion 38 of the inner cylindrical portion 35 of the crown, and the stopper 38a.
And the coil spring 37 is integrally fixed in front of the crown 34. Further, the projection 41 of the eraser holder 40 having the eraser 44 fixed to the rear end is engaged with and inserted into the spiral portion of the coil spring 37. In this state,
The engaging portion 34b of the outer cylindrical portion 34a of the crown is elastically fitted to the engaging portion 33 of the shaft portion 4b of the rear shaft by being inserted into the rear inner hole of the rear shaft 4, and the crown 4 is attached to the rear shaft 4. 34 is rotatably locked.
The coil spring 37 is formed in a spiral shape by a wire rod having a round cross section or a rectangular wire rod. Also, eraser 44
The direction of rotation of the crown 34 with respect to the appearance and disappearance of is selected by the winding direction of the coil spring 37.

Further, at that time, the slit portion 36a of the cylindrical cam is provided.
The eraser holder 40 is mounted in the cylindrical portion 36 having the above, the protrusion 41 is fitted in the slit portion 36a, and the eraser holder 40 is guided so as to be axially movable only with respect to the rear shaft 4. By the way, the eraser holder 40 has a pair of elastic locking pieces 42 that sandwich the eraser 44 at the rear.
Is formed, and a locking protrusion 43 is provided on the inner surface of the locking piece 42. A protrusion 41 is formed on the front side surface of the locking piece 42. In this state, the outer shaft 3 of the crown is attached to the rear shaft 4.
When the 4a is rotated, the eraser holder 40 moves back and forth so that the eraser 44 can be retracted from the rear end hole 39 of the crown.

Further, the sliding piece 6 has a projection 22 on the outer surface thereof, and a central portion projects from the rear end surface of the projection 22 and both sides of the projection are substantially the same slope as the cam slope 14 of the cylindrical cam 5 described above. It has a slope. Further, there is provided a hole that abuts on the flange portion 24 of the core pipe 23 and projects and fits behind the core pipe 23 for a long time. Similarly to the sliding piece 6, the sliding piece 6'has a projection 22 'and a cam slope, and an engaging portion 26 for fixing the rear end of the writing body 8 such as a ballpoint pen is provided at the tip. The locking portion may be formed in a pipe shape and the rear end of the writing body may be fitted therein.

The mechanical pencil writing body 7 has a built-in general chuck mechanism, and is joined to the core pipe 23 through a joint 29 connected to the chuck mechanism at the rear end thereof.
A core pipe 23 protruding from the rear end of the sliding piece 6 is fitted with the sliding piece 6 in contact with a flange portion 24 provided at the rear of the sliding piece 6.
The rear end hole is closed with a tail plug 25 or the like. The lead-out is performed by moving the chuck by the axial transition of the sliding piece 6 in a state where the step portion 28 at the tip of the mechanical pencil writing body 7 is in contact with the inner step portion 27 of the tip shaft 3.

Explaining in the order of assembling, the mechanical pencil writing body 7 and the writing body 8 such as a ballpoint pen are connected to the sliding pieces 6 and 6'at their rear ends, respectively, and each of the guide portions 2 of the center shaft described above is connected. The front end face of each sliding piece 6, 6'and the partition 1 on the front face of the guide groove 9, 9 'are movably fitted in the guide grooves 9, 9'.
It is urged rearward by the return springs 30 and 30 'which are interposed between the rear and the rear side.

From this state, the cylindrical cam 5 is inserted into the rear end hole of the center shaft 1 and the projection 17 is elastically fitted into the circumferential groove 19, so that the center shaft 1 is rotatable by 180 degrees in the circumferential direction. Prevent it from coming off and fasten it. Also, mechanical pencil cursive script 7
The rear shaft 4 is capable of changing the stroke by the stroke required for feeding the center with respect to the center shaft 1 in a state where the writing body is housed or the writing body 8 such as a ball-point pen is not protruding. Is done. Since the sliding pieces 6, 6'are always urged rearward by the return springs 30, 30 ', the cam slopes of the protrusions 22, 22' are always kept in contact with the cam slope 14 of the cylindrical cam 5. ing.

Further, with the rear end surface of the front shaft 3 in contact with the front surface of the stepped portion 31 of the center shaft 1, the engagement portion 13 of the tubular portion 10 is elastically fitted into the engagement groove 12 of the front shaft 3. As a result, the front shaft 3 and the center shaft 1 are fixed in a rotation-stopping and slip-out preventing state. The front axle 3 can be attached and detached with an appropriate force. In this state, when the rear shaft 4 is rotated to one side with respect to the front shaft 3 or the center shaft 1, the sliding piece 6 moves forward and the notch 15 at the front end of the cam slope 14 of the cylindrical cam 5 is moved.
Is locked to the projection 22 of the sliding piece 6 of one of the mechanical pencil writing bodies 7, and the writing tip end portion is in a protruding state from the tip end tip opening. Further, when the rear shaft 4 is rotated to the other side with respect to the front shaft 3 or the center shaft 1, the sliding piece 6 retracts and the writing tip portion of the mechanical pencil writing body 7 is retracted from the tip end opening of the leading shaft. The 6 ”advances and the writing tip of the writing body 8 such as the other ballpoint pen projects from the tip end opening of the tip shaft.

FIGS. 3 and 4 show another corresponding example showing the engagement state between the protrusion 17 of the cylindrical cam and the center shaft 1 '. In this case, as means for fitting the protrusion 17 into the circumferential groove 50,
A partition wall 52 having an inclined surface 53 is provided on the upper wall of the guide groove 51 in which the protrusion 17 is fitted from the rear end of the center shaft 1 '.
The reason why the partition wall 52 is provided is to enhance the rigidity of the center shaft 1'at the engaging portion.

FIG. 5 shows a second embodiment of the present invention. This embodiment is almost the same as the first embodiment, and only different points will be described. As shown in the drawing, a vertical groove 61 is formed on the inner surface of the rear shaft 60 integrally formed with the cylindrical cam 5 '. The inward projection 65a at the rear end of the coil spring 65 is a slit portion 64a provided on one side of the inner cylindrical portion 64 of the crown 62.
The crown 62 and the coil spring 65 are integrally fixed together. A projection 67 provided on the side surface of the eraser holder 66 engages with the spiral portion of the coil spring 65, and is fitted into the vertical groove 61 of the rear shaft 60 to be guided. With the above, the crown 6 with respect to the rear shaft 60
When 2 is rotated, the eraser holder 66 moves axially, and the eraser 68 projects from the rear end of the crown 62.

[0019]

When the rear shaft 4 is rotated to one side with respect to the front shaft 3 or the center shaft 1, the notch 15 provided at the tip of the cam slope 14 of the cylindrical cam 5 of the mechanical pencil writing body 7 on one side as shown in FIG. It engages with the sliding piece 6 to project its writing tip portion from the tip end opening of the tip shaft. At this time, the protrusion 17 of the cylindrical cam 5 is located in the wide groove 48 in the circumferential groove 19 of the center shaft 1. In this state, when the rear end of the crown 34 is knocked and the cylindrical cam 5 is axially moved, the operation is transmitted to the sliding piece 6, the core pipe 23, and the mechanical pencil writing body 7, and the step portion 28 at the writing tip portion is moved. The chuck moves axially together with the joint 29 from the state of being in contact with the inner step portion 27 of the leading shaft 3 to feed the core. Further, when the rear shaft 4 is rotated to the other side with respect to the front shaft 3 or the center shaft 1, the mechanical pencil writing body 7 is retracted, and instead, the writing tip portion of the writing body 8 such as a ballpoint pen projects from the leading tip end opening. When the cursive body is stored or when the cursive body such as a ballpoint pen is projected, the protrusion 17
Is located in the narrow groove 48 of the circumferential groove 19 and knocks to the center shaft 1
Since the projection 17 does not contact the front wall 49d of the circumferential groove 19 with the wall 20 of the rear shaft 4 in contact with the rear end, the projection or the like is not destroyed. Next, when the outer cylinder portion 34a of the crown is rotated to the left and right with respect to the front of the rear shaft 4, the eraser holder 40 moves back and forth, and the eraser 44 appears and disappears from the rear end hole 39.
Since the second embodiment operates in the same manner, its explanation is omitted.

[0020]

As described above, according to the present invention, the rear shaft is integrally extended to the rear of the cylindrical cam, and the coil spring fixed to the crown is fitted into the rear shaft, so that the crown is moved backward. Since the metal is fixed to the shaft so that it can only rotate, the metal is replaced by resin as compared with the conventional example, the number of parts is omitted, the structure is simplified, the assembly is facilitated, and the cost is reduced. Further, according to the embodiment, the center shaft integrally provided with the front shaft and the guide portion is a resin molded product, and the protrusion provided on the side surface of the cylindrical cam is elastically fitted into the circumferential groove formed behind the center shaft, Further, since the center shaft is integrally provided with the engaging portion for joining the front shaft and the rear shaft, the number of parts is omitted as compared with the conventional double writing instrument, the structure is simplified, and the assembly is facilitated. Cost reduction is achieved. Further, even if an impact such as a fall at the rear end is applied, the protrusion that locks the cylindrical cam and the center shaft does not come into contact with the front wall of the circumferential groove, so problems such as damage are prevented.

[Brief description of drawings]

FIG. 1 is a longitudinal cross-sectional view of an essential part of the whole showing a first embodiment of the present invention.

FIG. 2 is an explanatory view showing an engagement state between a protrusion of a cylindrical cam and a circumferential groove of a center shaft.

FIG. 3 is an explanatory view showing another corresponding example of the engagement state between the protrusion of the cylindrical cam and the circumferential groove of the center shaft.

FIG. 4 is a cross-sectional view of an essential part of an engaging portion in FIG.

FIG. 5 is a longitudinal cross-sectional view of a main part of the whole showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Middle shaft 1 `Mid shaft 2 Guide part 3 Front shaft 4 Rear shaft 4a Cylinder part 4b Shaft part 5 Cylindrical cam 5` Cylindrical cam 6 Sliding piece 6` Sliding piece 7 Mechanical pencil writing material 8 Ballpoint pen and other writing material 9 Guide groove 9 ｀ Guide groove 10 Cylinder part 11 Knock spring 12 Engagement groove 13 Engagement part 14 Cam slope 15 Notch 16 Partition part 17 Projection 18 Vertical groove 19 Circumferential groove 20 Wall 21 Window 22 Projection 22 'Projection 23 Core pipe 24 Flange part 25 tail Plug 26 Engagement part 27 Inner step part 28 Step part 29 Joint 30 Return spring 30 'Return spring 31 Step part 32 Hole 32' Hole 33 Engagement part 34 Crown 34a Outer tube part 34b Engagement part 35 Inner tube part 36 Tube Part 36a Slit part 36b Step part 37 Coil spring 38 Slit part 38a Stopper 39 Rear end hole 40 Eraser holder -41 protrusion 42 locking piece 43 locking protrusion 44 eraser 45 inclined surface 46 narrow portion 47 wide groove 48 narrow groove 49a rear wall 49b inclined surface 49c rear wall 49d front wall 50 circumferential groove 51 guide groove 52 partition wall 53 Inclined surface 60 Rear shaft 61 Vertical groove 62 Crown crown 63 Outer cylinder part 64 Inner cylinder part 64a Slit part 65 Coil spring 65a Protrusion 66 Eraser holder 67 Protrusion 68 Eraser

Claims (4)

[Claims] 1. A guide part and a guide integrated with the center shaft by respectively providing engagement parts for fitting the front end of the resin-made front shaft and the front end of the resin-made middle shaft in a non-rotatable and retaining state, and fixing them. The cursive body is fitted in the guide grooves of the guide part between the guide part and the sliding piece so that it can be moved back and forth by urging the return springs. -Shaped cylindrical cam is rotatably prevented with respect to the guide portion or the center shaft, and each sliding piece is brought into contact with the inclined surface of the cam to alternately move back and forth by the rotation of the cylinder cam with respect to the leading shaft or the center shaft. In a compound writing instrument capable of selectively projecting and retracting the tip of each writing body from the tip opening of the tip shaft, a rear shaft is integrally provided behind the cylindrical cam, and a resin ceiling is provided at the rear end of the rear shaft. The crown is locked so that it can only rotate, and the coil extends forward of the rear bore. A spring is arranged, the rear end of the coil spring is fixed to the crown, and an eraser holder having an elastic portion for sandwiching the eraser and a protrusion on the side surface engages the protrusion with the spiral portion of the coil spring. In addition, the tip of the cursive body appears and disappears by rotating the rear shaft with respect to the front shaft or the center shaft while being guided only by axial movement with respect to the rear shaft, and the eraser appears and disappears by rotating the crown with respect to the rear shaft. A compound writing instrument characterized by being configured so that it is possible. 2. The multiple writing instrument according to claim 1, wherein at least one of them is a mechanical pencil writing body, and a cylindrical cam is axially shifted with respect to the center shaft and the guide cylinder so that the lead can be drawn out. . 3. A cylindrical portion extending rearwardly of the cylindrical cam into an inner hole of a rear shaft is formed, and a slit portion is provided rearward on a side surface of the cylindrical portion, and a protrusion of an eraser holder is fitted into the slit portion. The double-sided writing instrument according to claim 1, wherein the eraser holder can move only axially with respect to the rear shaft. 4. A vertical groove is formed on a side surface of an inner hole of the rear shaft, and a protrusion of the eraser holder is fitted into the vertical groove so that the eraser holder can only move axially with respect to the door shaft. The compound writing instrument according to claim 1.