JP2606843Y2 - 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 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 filed by the present applicant, a sliding groove for guiding two writing objects is provided on a front shaft. At the front end, a guide cylinder to be fixed and a cam slope contacting a sliding piece attached to two writing bodies fitted to the guide cylinder are provided at a front end portion, and a rear end is formed as a knock portion with respect to the cap. A cylindrical cam mounted so as to be movable in the axial direction and to rotate in the circumferential direction is integrated. There are multiple writing instruments that can appear and disappear.
Further, as a cited example of the present application, as shown in Japanese Utility Model Application Laid-Open No. 60-120889 by the same applicant, there is a double writing instrument in which a crown protruding from a rear end of a cap is rotated to make an eraser appear and disappear. .

[0003]

The above cited reference has the problem that metal parts are used in many parts, the structure is complicated, the number of parts increases, and the cost increases.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a double writing instrument according to the present invention has a front end made of a resin and a front end made of a middle shaft made of a resin fitted to each other so as to be non-rotatable and non-removable. An engaging portion to be attached is provided, and both are fixed, and a return spring is provided between the sliding piece provided at the rear end of the writing body and the guide portion on the guide portion provided integrally with the inner hole of the center shaft. The cursive body is urged rearward and fitted back and forth freely,
A cylinder having a substantially L-shaped window formed by connecting a vertical groove and a peripheral groove through a narrow portion on a rear side surface of the center shaft, and a cam slope displaced in the axial direction is provided circumferentially at a front end portion. A projection is provided on the side surface of the cam, and the projection is elastically fitted into the circumferential groove to prevent the cylindrical cam from rotating and moving in a certain range with respect to the central shaft and to be able to move axially. By rotating the cylindrical cam with respect to the front shaft or the center shaft, the front and rear are alternately moved back and forth, so that the tip of each writing body can be selectively made to come and go from the front end of the front shaft, and at least one of the writing bodies is a mechanical pencil writing body. Only when the mechanical pencil is selected, the cylindrical cam shifts with respect to the center shaft so that the core can be extended, and a cylindrical portion having a slit behind the cylindrical cam is integrally provided, and the cylindrical portion is provided. With a resin cap and a cylindrical cam An elastic portion for holding the eraser in the cylindrical portion of the cylindrical cam and an eraser holder having a protrusion on the front cylindrical portion are fitted with the protrusions fitted in the slits. A spiral groove is formed in the inner hole, and a cylindrical part with a slightly smaller diameter is provided in front of the outer peripheral part and a cylindrical part behind the outer peripheral part, and the front end of the rear cylindrical part is brought into contact with the rear end of the cap. The front cylinder portion is fitted in the rear inner hole of the cap in a state where the cylinder portion of the cylindrical cam is fitted, the crown is fixed to the cap so that it can only rotate, and the projection of the eraser holder is It is made to fit into the spiral groove through the slit, and the eraser can come and go by rotating the cylinder behind the crown with respect to the cap.

[0005]

1 and 3 show an embodiment of the present invention. The dual writing implement of the present invention has a central shaft 1, a front shaft 3, a cylindrical cam 5, a pair of sliding pieces 6, a 6 ｀ mechanical pencil 7, a writing body 8 such as a ballpoint pen, a cap, and a cap, which are integrally provided with a guide cylinder 2 as a guide portion. The four crowns 34, the eraser holder 40, and the eraser 46 are main components. First, the center shaft 1 is made of resin, and as shown in FIG. 1, has 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. A guide tube 2 is provided. The front half of the guide tube 2 is provided with a cylindrical portion 10 having a partition portion 16 having holes 32, 32 ° communicating with the respective guide grooves 9, 9 ° and having an open front end. A stepped portion 31 is formed, and a bulging engagement portion 13 is formed on a front outer peripheral portion of the stepped portion 31.

On the rear side surface of the center shaft 1, as shown in FIG. 2, a vertical groove 18 is connected to a peripheral groove 19 via a slope 47 at the front, 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 47, passes through the narrow portion 48, 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 49 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 51 of the circumferential groove 19 is so arranged that the cylindrical cam 5 cannot move substantially in the axial direction at the position of the projection 17 when the projection is made.
a narrow groove 50 is provided by connecting the inclined surface 51b between the rear surface 51a and the rear wall 51c. As will be described later, the cylindrical cam 5
Is set so that the stepped portion 21 of the cap 4 contacts the rear end of the center shaft 1 and the front end of the projection 17 does not contact the front wall 52 of the circumferential groove 19 when moving 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 circumferential stepped portion 21 formed in the inner hole on the front side. An engaging portion 33 having a circumferential groove is formed in the rear inner hole. Cylindrical cam 5
Has a cam slope 14 which is displaced circumferentially back and forth at the front end edge, and a notch 15 is formed at the foremost end of the cam slope 14. Also, on the side surface of the cylindrical cam 5, the center shaft 1 is provided.
A projection 17 is formed which is inserted into the vertical groove 18 and elastically fits into the circumferential groove 19 to be rotated and prevented from falling out within a certain range (approximately 180 degrees).

The cylindrical cam 5 has a cylindrical portion extending rearward, and a circumferential flange 20 is formed on the side surface of the cylindrical portion.
Further, a long slit 37 is formed behind the step portion 45. On the other hand, the crown 34 made of resin has a spiral groove 36 in its inner hole.
Is formed, a tubular portion 34 # is provided at the rear and a tubular portion 35 is provided at the front, and a protruding engagement portion 35 # is formed on the peripheral surface of the tubular portion 35. The cylindrical cam 5 is fitted in the inner hole of the cap 4, and the flange 20 abuts the step 21. A groove and a rib or a non-circular portion are provided between the peripheral surface of the cylindrical cam and the inner surface of the step portion, and the rotation is stopped. (Not shown)
It is also possible to provide a part for stopping rotation between the flange 20 and the inner hole of the cap 4.

By the way, the cylindrical portion 35 of the crown 34 is fitted in the rear inner hole of the cap 4 while being fitted on the outer periphery of the cylindrical portion having the slit 37, and the engaging portion 35 Is elastically fitted to the engaging portion 33 of the cap 4, and the flange 20 of the cylindrical cam 5 is clamped between the step 21 of the cap and the tip of the cylindrical portion 35 of the crown. 5, the crown 34 is fixed to the cap 4 so that it can only rotate.

An eraser holder 40 having an eraser 46 fixed to the rear end is mounted in the cylindrical portion having the slit 37 of the cylindrical cam. The eraser holder 40 is formed with a pair of elastic pieces 43 that sandwich the eraser 46 at the rear, and has an engaging projection 44 on the inner surface of the elastic piece 43. A projection 42 is formed on the outer periphery of the front cylindrical portion 41. The eraser holder 40 has a protrusion 42 and an elastic piece 43 fitted in the slit 37 of the cylindrical portion.
6 and is disposed in the tubular portion. In this state, when the cylindrical portion 34 ° of the crown is rotated with respect to the cap 4, the eraser holder 40 moves back and forth, and the eraser 46 can be protruded and retracted from the rear end hole 38 of the crown.

The sliding piece 6 has a projection 22 on the outer surface, a central portion protruding from the rear end surface of the projection 22, and both sides thereof have a cam having substantially the same gradient as the cam slope 14 of the cylindrical cam 5 described above. It has a slope. 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. In the drawing body 8 such as a mechanical pencil 7 and a ballpoint pen, each sliding piece 6, 6 # is connected to the rear end, and each of the guide shafts 2 of the center shaft described above 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.

On the other hand, the cylindrical cam 5 is fitted in the inner hole of the cap 4, and an eraser holder 40 having an eraser 46 fixed thereto is fitted in a cylindrical portion having a slit 37, and the cylindrical portion 35 of the crown 34 is mounted. The cylindrical cam 5 is fitted in the inner hole of the cap 4 so as to be fitted, the crown 34 is fixed to the cap 4 so that it can only rotate, and the flange 20 of the cylindrical cam is set to the step of the cap. The cylindrical cam 5 is integrated with the cap by being sandwiched between the portion 21 and the tip of the cylindrical portion 35. At this time, the projection 42 of the eraser holder 40 is elastically fitted into the spiral groove 36. (In order to fit the projection 42 into the spiral groove 36, there is an operation of fitting the crown 34 while rotating the crown appropriately.) As described above, when the crown portion 34 ° of the crown is rotated left and right with respect to the cap 4, the rear end The eraser 46 comes out of the hole 38.

In this state, 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 180 ° in the circumferential direction with respect to the central shaft 1. Stop and secure. In addition, mechanical pencil 7
Is protruded, the cap 4 can be shifted by the stroke necessary for centering the core 1 with respect to the center shaft 1, and when the writing body is stored or the writing body 8 such as a ballpoint pen projects,
Axis transition is made impossible. Since the sliding pieces 6, 6 # are constantly urged rearward by the return springs 30, 30 #, the cam slopes of the projections 22, 22 # are always kept in contact with the cam slope 14 of the cylindrical cam 5. ing.

The engaging portion 13 of the cylindrical portion 10 is elastically fitted in 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.

FIGS. 3 and 4 show another example of the engagement between the projection 17 of the cylindrical cam and the central shaft 1 °. In this case, as means for fitting the projection 17 into the circumferential groove 60,
A partition wall 62 having an inclined surface 63 is provided on an upper wall of a guide groove 61 in which the projection 17 is fitted from the rear end of the central shaft 1 #.
The reason for providing the partition wall 62 is to enhance the rigidity of the center shaft 1 ° at the engaging portion.

[0019]

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 49 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 shifted axially, 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 a state in which the chuck comes into contact with 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 is retracted, and the writing tip of the writing body 8 such as a ball-point pen projects from the tip of the front shaft. In addition, when the cursive body is stored, when the cursive body such as a ballpoint pen is projected,
The projection 17 is located in the narrow groove 50 of the peripheral groove 19, and the projection 17 contacts the front wall 52 of the peripheral groove 19 in a state where the projection 17 is knocked and abutted against the step 21 of the cap 4 at the rear end of the center shaft 1. Since it does not, the projections and the like do not break. Next, when the crown 34 is rotated left and right with respect to the front of the cap 4, the eraser holder 40 moves back and forth, and the eraser 46 comes out of the rear end hole 38.

[0020]

As described above, according to the present invention, the cylindrical portion having the slit is extended behind the cylindrical cam, the cylindrical cam is fitted in the resin cap, and the spiral groove is formed in the inner hole. The formed resin crown was fitted to the cap in a state of being fitted to the cylindrical portion of the cylindrical cam, and the cylindrical cam was integrated with the cap, and the crown was fixed so that it could only rotate with respect to the cap. As compared with the conventional example, the metal is replaced with a resin, the number of parts is omitted, the structure is simplified, the assembling is easy, and the cost is reduced. Further, according to the embodiment, the front shaft, the center shaft integrally provided with the guide portion as a resin molded product,
Conventionally, the protrusion provided on the side surface of the cylindrical cam is elastically fitted into a peripheral groove formed in the rear of the central shaft, and the central shaft is integrally provided with an engaging portion for joining with the front shaft and the cap. The number of parts is omitted for the dual writing instrument, the structure is simplified,
Moreover, assembling is facilitated, and further cost reduction is achieved. 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 longitudinal cross-sectional view of an entire main part showing an 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 an explanatory view showing another example of an engagement state between a projection of a cylindrical cam and a peripheral groove of a center shaft.

FIG. 4 is a cross-sectional view of a main part of an engaging portion in FIG. 3;

[Explanation of symbols]

 Reference Signs List 1 center shaft 1 ｀ center 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 cylinder part 11 knock spring 12 Mating groove 13 Engagement part 14 Cam slope 15 Notch 16 Partition part 17 Projection 18 Vertical groove 19 Peripheral groove 20 Flange part 21 Step part 22 Projection 22 ｀ Projection 23 Core pipe 24 Flange part 25 Tail plug 26 Lock part 27 Inner part 28 step portion 29 joint 30 return spring 30 リ タ ー ン return spring 31 step portion 32 hole 32 ｀ hole 33 engagement portion 34 crown 34 ｀ cylinder portion 35 cylinder portion 35 ｀ engagement portion 36 spiral groove 37 slit 38 rear end hole 39 Contact part 40 eraser holder 41 cylindrical part 42 projection 43 elastic piece 44 locking projection 45 step 46 eraser 47 inclined surface 48 Isthmus 49 Habahiromizo 50 Habasemamizo 51a rear wall 51b inclined face 51c rear wall 52 front wall 60 peripheral groove 61 guide groove 62 partition wall 63 inclined surface

Claims (1)

(57) [Scope of request for utility model registration] 1. A guide in which a resin-made front shaft and a resin-made middle shaft are provided with engaging portions which are fitted to each other in a non-rotatable and non-removable state, and are fixed to each other. A cam that displaces in the axial direction by providing a return spring between the sliding piece provided at the rear end of the writing body and the guide part to urge each writing body backward and to be able to move back and forth freely. A cylindrical cam provided with a slope at the front end at the front end is rotatably retained with respect to the center shaft, and each sliding piece is brought into contact with the cam slope so that the rotation of the cylindrical cam with respect to the front shaft or the center shaft alternately moves back and forth. By moving the writing tool, the tip of each writing tool can be selectively protruded and retracted from the tip end of the tip shaft.At least one of the writing tools is a mechanical pencil writing tool. Is made possible,
Further, a cylindrical portion having a slit 37 is provided integrally with the rear of the cylindrical cam 5, and a resin cap 4 is provided integrally with the cylindrical portion and the resin cap 4 is provided integrally with the cylindrical cam 5. The elastic portion for sandwiching the eraser 46 in the portion and the front cylindrical portion 41
An eraser holder 40 having a projection 42 is fitted with the projection 42 fitted in the slit 37. The crown 34 made of resin has a spiral groove 36 formed in the inner hole and a rear portion of the outer periphery. A slightly smaller-diameter cylindrical portion 35 is provided in front of the cylindrical portion 34 ', and a front end of the cylindrical portion 34' is
4 is brought into contact with the rear end, and the front cylindrical portion 35 is
In the rear inner hole of the cap 4 in a state where the cylindrical portion is fitted.
The crown 34 is fixed to the cap 4 so that it can only rotate, and the projection 42 of the eraser holder 40 is fitted into the spiral groove 36 through the slit 37, so that the front shaft 3 or the center shaft 1 is inserted. By rotating the cap 4 with respect to the cap, the tip of the cursive appears and disappears.
4. A double writing implement characterized in that the eraser 46 is made to be able to protrude and disappear by rotating the rear cylindrical part 34 # of the fourth writing implement.