JP2605500Y2 - Double writing instrument - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the provision of a double-type writing instrument in which the tips of a plurality of writing bodies are made to be able to come and go alternately at a tip end of a front shaft and an eraser is made to come and go from the rear end of a cap.

[0002]

2. Description of the Related Art Conventionally, as an example of a double-type 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 objects is provided on a front shaft. The front end has a guide tube fixed to the guide tube and a cam slope contacting a sliding piece attached to two writing bodies fitted to the guide tube, and the rear end forms a knock portion to the cap. Equipped with a cylindrical cam mounted so as to be movable in the axial direction and integrated in the circumferential direction, and by selectively rotating the cap with respect to the front shaft, two writing bodies can be selectively placed at the front end of the front shaft. There are multiple writing instruments that can appear and disappear.
Further, as a cited example of the present application, there is a double writing instrument in which an eraser is made to protrude and disappear by rotating a crown protruding from the rear end of a cap as seen in Japanese Utility Model Application Laid-Open No. 60-120889 by the present applicant. .

[0003]

The above cited reference has a first problem in that metal parts are used in many parts, the structure is complicated, the number of parts is increased, and the cost is increased. or,
Since the crown that protrudes from the rear end of the cap is short, there is a second problem in that it is difficult to pick with a finger, and it is difficult to operate the eraser in and out. In addition, the same applicant filed a similar application on June 9, 1992 (Japanese Utility Model Application Laid-Open No. 6-34990). It is an improvement.

[0004]

SUMMARY OF THE INVENTION The dual writing implement of the present invention devised to solve the above-mentioned problem has the following configuration and features. An engaging portion for fitting the front end of the resin-made shaft and the front end of the resin-made middle shaft in a non-rotatable and non-removable state is provided respectively, and both are fixed, and a plurality of guide grooves of a guide cylinder integrated with the middle shaft are provided. A return spring is provided between the guide cylinder and the sliding piece with at least one of the writing pieces fixed to the rear end of the sliding piece and a mechanical pencil, and each writing piece is urged rearward. In the compound writing instrument which is fitted so as to be able to move back and forth in the axial direction, a substantially L-shaped window portion is formed in the rear side surface of the center shaft by connecting a vertical groove and a circumferential groove at a narrow portion. Also, a projection is provided on a side surface of a cylindrical cam in which a cam slope displaced in the axial direction is circumferentially provided at a front end portion,
The projection is elastically fitted into the circumferential groove having a wide groove and a narrow groove by the inclined surface through the vertical groove, so that the cylindrical cam can rotate within a certain range with respect to the guide cylinder and the center shaft, and the shaft can be shifted. The sliding pieces are prevented from falling off, and the sliding pieces come into contact with the cam slopes of the cylindrical cams. When the mechanical pencil is selected, the cylindrical cam can be shifted and the lead can be extended.When the cylindrical cam is moved forward, the cylindrical cam protrudes to the front wall of the circumferential groove. It is set so that it does not abut. In addition, a slit is provided in the cylindrical portion extending behind the cylindrical cam to form a resin cap, and protrusions and grooves are alternately provided on both sides of the slit of the cylindrical portion, and an eraser is fixed to the rear. An eraser holder is mounted by removably engaging a protrusion provided on the outer periphery thereof with the groove of the slit, and moving the eraser holder back and forth with respect to the cap so that the eraser can freely come out of the rear end of the cap. . As described above, since the dual writing instrument of the present application has a simplified number of parts and a simple structure, the assembly is easy and the cost can be reduced. Further, the operation of feeding the eraser is easy. In addition, even if a drop impact is applied to the rear end of the cap, the projection of the cylindrical cam does not abut against the front wall of the circumferential groove, so that the projection and the like are prevented from being broken.

[0005]

1 and 2 show a first embodiment of the present invention. The dual writing implement of the present invention includes a central shaft 1 integrally provided with a guide tube 2, a front shaft 3, a cap 4 integrally provided with a cylindrical cam 5, a pair of sliding pieces 6, 6 ｀, a pencil pencil writing body 7, a ballpoint pen, and the like. Cursive 8, eraser holder 3
6. The eraser 50 is a main component. First, center axis 1
As shown in FIG. 1, is a guide tube 2 having an axially long guide groove 9 opened to the side surface from a substantially central portion to a rear end and a similar guide groove 9 ｀ on the opposite side surface. Is provided. The front half of the guide tube 2 is provided with a tube portion 10 having a partition portion 16 having holes 41, 41 ° communicating with the respective guide grooves 9, 9 ° and having an open front end. A step portion 31 is provided at an end, and a bulging engagement portion 13 is formed on the outer peripheral portion in front of the step portion 31.

On the rear side surface of the center shaft 1, as shown in FIG. 2, a longitudinal groove 18 is connected to a circumferential groove 19 via a slope 42 on the front side, and a substantially L-shaped window portion is formed. Are drilled. As will be described later, the projection 17 of the cylindrical cam 5 is inserted from the vertical groove 18, and the projection 17 elastically expands the inclined surface 42, passes through the narrow portion 43, and enters the circumferential groove 19. The cylindrical cam 5 rotates while the projection 17 abuts on the rear wall of the circumferential groove 19 in the circumferential direction, so that the writing part of the writing body 8 such as the mechanical pencil 7 or the ballpoint pen alternately protrudes and retracts from the front end of the front shaft. Become. The circumferential groove 19 is provided with a wide groove 44 so that the cylindrical cam 5 can move axially at the position of the projection 17 when the mechanical pencil 7 protrudes. The rear wall 46 of the circumferential groove 19 is arranged such that the cylindrical cam 5 cannot move substantially in the axial direction at the position of the projection 17 at the time the
a narrow groove 45 is provided between the a and the rear wall 46c to connect the inclined surface 46b. As will be described later, the cylindrical cam 5
Is set such that the wall 20 of the cap 4 abuts on the rear end of the center shaft 1 and the front end of the projection 17 does not abut on the front wall 47 of the circumferential groove 19 when the front end is moved forward.

[0007] The front end of the shaft 3 is tapered, and the front end of the shaft 3 has an inner step 27 at the end of the inner hole. In the rear end hole, an engagement groove 12 is provided, which engages with an engagement portion 13 provided on the outer peripheral portion of the cylindrical portion 10 of the guide cylinder, and prevents the cylindrical portion 10 from slipping out and rotating. . The cylindrical portion 10 and the front shaft 3 are detachably fixed by an appropriate force. (Showa 6
(Same as the configuration of the front shaft in JP-A-4-3491)

The cap 4 is made of resin and has a cylindrical cam 5 at the tip.
Are integrally provided. The cylindrical cam 5 has a cylindrical shape, and has a cam slope 14 that is displaced circumferentially back and forth at a front end edge, and a notch 15 is formed at the foremost end of the cam slope 14. or,
On the side surface of the cylindrical cam 5, there is formed a projection 17 which is inserted into the vertical groove 18 of the center shaft 1 and elastically fits into the circumferential groove 19 to rotate and prevent it from falling out within a certain range (about 180 degrees).

The cap 4 has a tubular portion extending behind the cylindrical cam 5, and a slit 3 is provided on the side surface of the tubular portion.
2, a projection 33 and a groove 3 are provided on both sides of the slit 32.
4 are provided alternately. Further, an eraser holder 36 having an eraser 50 fixed to the rear end thereof is mounted in the cylindrical portion so that an engagement protrusion 39 provided on an outer periphery thereof is removably fitted into the groove 34 of the slit 32. The engagement protrusion 39 is formed at the tip of an elastic piece 38 provided on the side surface of the eraser holder 36, and engages while elastically displacing with the groove 34 while sliding to keep the eraser 50 in the projected state. Also, the engagement protrusion 3
The center of 9 is slightly protruded to form an operation projection 40, and the operation projection 40 is moved back and forth to release the engagement between the engagement projection 39 and the groove 34, thereby enabling the eraser holder 36 to move. A crown 35 is fixed to the rear end of the cylindrical portion.
The rear end portion 48 of the cylindrical portion and the contact portion 49 of the crown 35 form an inclined surface and are substantially in contact with each other, thereby suppressing deformation of the rear end of the slit 32.

The sliding piece 6 has a projection 22 on its outer surface.
The rear end surface of the projection 22 has a central portion protruding, and both sides thereof have a cam slope having substantially the same gradient as the above-described cylindrical cam 45 cam slope 14. Further, a hole is provided which abuts against the flange portion 24 of the core pipe 23 to protrude and fit the rear of the core pipe 23 long. The sliding piece 6 # has a projection 22 # and a cam slope like the sliding piece 6, and a locking portion 26 for fixing the rear end of the writing body 8 such as a ball-point pen is provided at the tip. Incidentally, the locking portion may be formed in a pipe shape and the rear end of the writing body may be fitted.

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

Next, a description will be given in assembling order. A writing body 8 such as a mechanical pencil 7 and a writing pen 8 such as a ball-point pen are connected with respective sliding pieces 6 and 6 # at the rear ends thereof, so that each of the above-mentioned center axis guide cylinders 2 is connected. It is movably fitted in the guide grooves 9, 9 ｀, and the front end face of each sliding piece 6, 6 ｀ and the partition 1 on the front of the guide grooves 9, 9 ｀.
6 is urged rearward by return springs 30 and 30 # interposed between the springs. The cap 4 is configured such that the cylindrical cam 5 is inserted into the rear end hole of the central shaft 1 so that the projection 17 is elastically fitted into the circumferential groove 19, and is rotatable at substantially 180 degrees in the circumferential direction with respect to the central shaft 1 and is prevented from coming off. Is stopped. In a state where the mechanical pencil 7 is protruded, the cap 4 can be shifted by the stroke necessary for centering the center shaft 1 with respect to the center shaft 1, and when the cursive body is stored or the writing body 8 such as a ballpoint pen is protruded. The axis transition is made impossible. Each sliding piece 6, 6 ｀
Is always urged rearward by the return springs 30 and 30 °, so that the cam slopes of the projections 22 and 22 ° always contact the cam slope 14 of the cylindrical cam 5.

The engaging portion 13 of the cylindrical portion 10 is elastically fitted into the engaging groove 12 of the front shaft 3 with the rear end surface of the front shaft 3 in contact with the front surface of the step portion 31 of the center shaft 1. Thus, the front shaft 3 and the center shaft 1 are fixed in a state where rotation is prevented and the shaft is prevented from coming off. The tip shaft 3 is detachable with an appropriate force. When the cap 4 is rotated in one direction with respect to the front shaft 3 or the center shaft 1 in this state, the sliding piece 6 advances, and the notch 15 at the foremost end of the cam slope 14 of the cylindrical cam 5 becomes one of the mechanical pencils 7. The writing tip is locked to the projection 22 of the sliding piece 6 so that the writing tip projects from the tip end of the front shaft. Further, when the cap 4 is rotated to the other end with respect to the front shaft 3 or the center shaft 1, the sliding piece 6 is retracted so that the writing tip of the mechanical pencil 7 penetrates from the tip of the leading shaft and the sliding piece 6 is moved.前進 moves forward, and the writing tip of the writing body 8 such as a ballpoint pen projects from the tip end of the front shaft.

On the other hand, an eraser holder 36 is fitted from the rear end of the cylindrical portion of the cap 4, and the engaging projections 39 of the eraser holder 36 are engaged with the grooves 34 of the slits 32 provided in the cylindrical portion. Is slidable with respect to the cylindrical portion. The crown 35 is fixed to the rear end of the cylindrical portion, and the eraser 50 is inserted from the opening at the rear end of the crown 35, and the rear end of the eraser 50 is fixed to the eraser holder 36.
As described above, when the eraser holder 36 is moved back and forth, the eraser 50 appears and disappears from the opening of the crown 35. The inner diameter of the opening of the crown 35 is provided slightly larger than the outer diameter of the eraser 50.

FIG. 3 shows a second embodiment of the present invention. This embodiment is almost the same as the previous embodiment, and only the differences will be described. Sliding piece 5 fixed to the rear end of core pipe 55
There is a tubular portion extending behind 1, a cutout window 54 communicating with the hole 52 is formed on the outer side, and a rear end 53 is provided integrally. The core pipe 55 is fitted into the hole 52, and the rear end of the core pipe 55 is in close contact with the rear end 53. The reason why the sliding piece 51 is provided in this way is that the cost is reduced by omitting the members and processing the core pipe. or,
The reason why the cutting window 54 is provided is that when the mechanical pencil 7 protrudes from the front end of the front shaft 3, it is centered at the front end and the cylinder portion behind the sliding piece 51 is pressed against the inner wall of the cylindrical cam 5. , Provided as an escape at that time. Without the cutout window 54, the mechanical pencil cannot be centriped and poor sliding occurs. Alternatively, it is necessary to increase the inner diameter of the cylindrical cam 5 (that is, the center shaft becomes thicker), resulting in a problem that the appearance is deteriorated.

[0016]

When the cap 4 is rotated in one direction with respect to the front shaft 3 or the center shaft 1, the cam slope 1 of the cylindrical cam 5 is rotated as shown in FIG.
A notch 15 provided at the front end of the pen 4 engages with the sliding piece 6 of one of the mechanical pencils 7 to protrude the writing end from the front end of the front shaft. At this time, the projection 17 of the cylindrical cam 5 is located in the wide groove 44 in the circumferential groove 19 of the center shaft 1. In this state, when the rear end of the crown 35 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 7 and the step 28 of the writing tip is moved. From the state in which the chuck abuts on the inner step portion 27 of the front shaft 3, the chuck moves along with the joint 29 so that the core is extended. When the cap 4 is rotated to the other end with respect to the front shaft 3 or the center shaft 1, the mechanical pencil 7 retreats, and instead the writing tip of the writing pen 8 such as a ballpoint pen projects from the tip of the front spindle. In addition, when the cursive body is stored, when the cursive body such as a ballpoint pen protrudes,
The projection 17 is located in the narrow groove 45 of the circumferential groove 19 and the crown 35
When the rear end is knocked, the wall 20 of the cap 4 comes into contact with the rear end of the center shaft 1 and the projection 17 does not come into contact with the front wall 47 of the circumferential groove 19, so that the projection or the like does not break. . It is to be noted that even when the writing tip of the mechanical pencil is protruding from the tip end of the front shaft, the projection 17
Does not contact the front wall 47 of the circumferential groove 19.

Next, when the operation projection 40 of the eraser holder 36 is pressed and retracted with respect to the cap 4, the engagement projection 3
9 moves away from the groove 34 of the slit 32,
The eraser holder 36 gradually retreats, and the eraser 50
Is fed out from the opening of the crown 35. Also, the operation protrusion 4
When “0” is pushed forward, the eraser holder 36 advances, and at the same time, the eraser 50 enters through the opening of the crown 35.

[0018]

As described above, according to the present invention, the center shaft integrally provided with the leading shaft and the guide portion is formed as a resin molded product, and the protrusion provided on the side surface of the cylindrical cam is elastically provided in the circumferential groove formed in the rear of the center shaft. And the central shaft is integrally provided with an engaging portion for joining with the front shaft and the cap, so that the number of parts is reduced with respect to the conventional dual writing implement, the structure is simplified, and assembly is easy. And cost reduction is achieved. In addition, a slit provided with a projection and a groove alternately formed in the cylindrical portion behind the cap is formed so that the projection of the eraser holder fitted in the cylindrical portion is engaged with the groove of the slit. However, metal parts are replaced with resin, and the number of parts is reduced.
Further, since the assembly is facilitated, the cost can be reduced and the product can be provided at a low cost. In addition, since the operation projection is provided so as to be able to move back and forth, the operation of feeding out the eraser is easy and the usability is good. Further, even when an impact such as a rear end drop is applied, the projection for locking the cylindrical cam and the central shaft does not abut against the front wall of the peripheral groove, thereby preventing a problem such as breakage.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of the entire main part showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an engagement state between a projection of a cylindrical cam and a peripheral groove of a center shaft.

FIG. 3 is a longitudinal sectional view of the entire main part showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Middle shaft 2 Guide cylinder 3 Front shaft 4 Cap 5 Cylindrical cam 6 Sliding piece 6 ｀ Sliding piece 7 Mechanical pencil writing body 8 Writing body such as ballpoint pen 9 Guide groove 9 ｀ Guide groove 10 Cylindrical part 11 Knock spring 12 Engaging groove 13 Engaging part 14 Cam slope 15 Notch 16 Partition part 17 Projection 18 Vertical groove 19 Peripheral groove 20 Wall 21 Window 22 Projection 22 ｀ Projection 23 Core pipe 24 Flange part 25 Tail plug 26 Locking part 27 Inner part 28 Step part 29 Joint Reference Signs List 30 return spring 30 return spring 31 step 32 slit 33 protrusion 34 groove 35 crown 36 eraser holder 37 fitting portion 38 elastic piece 39 engagement protrusion 40 operation protrusion 41 hole 41 操作 hole 42 inclined surface 43 narrow portion 44 width Wide groove 45 Narrow groove 46a Rear wall 46b Inclined surface 46c Rear wall 47 Front wall 48 Rear end 49 Part 50 eraser 51 sliding pieces 52 holes 53 rear portion 54 cut window 55 tubular core

Claims (2)

(57) [Scope of request for utility model registration] A plurality of guide cylinders integrated with a center shaft are provided by providing engaging portions for fitting the front end of the resin shaft and the center shaft of the resin in a non-rotatable and non-removable state. In the guide groove, at least one writing piece with the sliding piece fixed to the rear end is made of a mechanical pencil, and a plurality of writing pieces are provided with a return spring between the guide cylinder and the sliding piece, and each writing piece is moved backward. And a substantially L-shaped window in which a vertical groove and a circumferential groove are connected to a rear side surface of the center shaft by a narrow portion at the rear side surface of the center shaft. A projection is provided on the side surface of a cylindrical cam having a cam slope displaced in the axial direction at the front end thereof, and the projection is formed by the inclined surface through the vertical groove. The cylindrical cam is fitted elastically into the circumferential groove having a narrow groove so that the cylindrical cam is Each sliding piece is rotated in a fixed range, and the axis can be shifted.The sliding piece is abutted against the cam slope of the cylindrical cam. To allow the tip of each cursive body to be selectively protruded and retracted from the tip of the tip of the tip shaft.When the mechanical pencil is selected, the cylindrical cam can be shifted axially and the core can be extended, and the cylindrical cam can be moved forward by moving the cylindrical cam forward. A compound writing implement characterized in that the projection of the cam is set so as not to contact the front wall of the circumferential groove. 2. A resin cap is formed by providing a slit in a cylindrical portion extending rearward of the cylindrical cam, and a projection and a groove are alternately provided on both sides of the slit of the cylindrical portion, and an eraser is provided rearward. A fixed eraser holder is attached by detachably engaging a protrusion provided on its outer periphery with the groove of the slit, and attached.
2. The double writing implement according to claim 1, wherein the eraser holder is moved back and forth with respect to the cap so that the eraser can be freely protruded and retracted from the rear end of the cap.