JP2000289387A - Eraser extending device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eraser extending device which is of a simple structure with a reduced number of parts and can be easily assembled at a low cost. SOLUTION: The forward end of a barrel 4a has a connecting part formed to allow no insertion of an eraser holder 37, and slits 32 are provided by perforating longitudinal grooves of small width at the rear end of a longitudinal stretch in the axial direction and transverse grooves of slightly large width which are almost orthogonal with the longitudinal grooves, both longitudinal and transverse grooves being properly spaced from each other at a plurality of spots. In addition, the eraser holder 37 is structured of a rib standing upright on the side face of a barrel part 9 at the rear end as a supporting shaft and a platelike slider monolithically formed with the rib toward the forward part of and in parallel with the barrel part 9. Further, an engaging protrusion is formed in the barrel part 9 appropriately backward of the rib, and the rib of the eraser holder 37 is fitted into the longitudinal grooves of the slit and at the same time, the engaging protrusion is detachably fitted into the transverse grooves of the slit. A crown 36 has an internal barrel integrally formed with the inner wall 44 of an external barrel 45 and the rear end part of the barrel 4a is fitted to the barrel 4a in such a way that the rear end part is inserted into a space between the external barrel 45 and the internal barrel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eraser feeding device connected to a rear end of a writing mechanism.

[0002]

2. Description of the Related Art Conventionally, a mechanical pencil or at least one
2. Description of the Related Art There is known a writing instrument in which a plurality of writing instruments, each of which has a mechanical pencil as a pencil, are mounted and an eraser feeding device is connected to a rear end of a double writing instrument that allows a writing tip to be selectively protruded and retracted from an axis. Such an eraser feeding device has a structure in which the eraser can come out from the rear end by rotating the shaft cylinder of the eraser feeding device or the crown provided at the rear end of the shaft cylinder with respect to the connected writing instrument part. It has been known. Also, with another structure, a slit is provided in the axial direction on the side surface of the shaft cylinder as in the present application, and the slider provided through the slit is slid along the slit, thereby being provided integrally with the slider. It is known that the eraser holder is moved back and forth so that an eraser fixed to the eraser holder is provided so as to protrude and retract from the rear end of the barrel.

[0003]

The conventional eraser feeding device has a problem that the structure is complicated, the number of parts is increased and the cost is increased, and the assembly is difficult.

[0004]

The present invention has the following arrangement to achieve the above object. The eraser feeding device according to claim 1 is provided with a slit in the axial direction on a side surface of the shaft cylinder, and a slider provided through the slit is slid in the front-rear direction along the slit. The eraser provided in the shaft cylinder is moved back and forth so as to interlock with the slider, and the rear end of the eraser fixed to the eraser holder is provided so that it comes out from the rear end of the shaft cylinder. In the feeding device, the front end of the barrel has a connection portion through which the eraser holder cannot be inserted, and the slit has
A narrow vertical groove drilled to the rear end in the axial longitudinal direction and a slightly wide horizontal groove substantially perpendicular to the vertical groove are provided by drilling at a plurality of locations at appropriate intervals, and the eraser holder is A plate-shaped slider is integrally formed with the rib rising on the side surface of the rear end of the cylinder portion as a support shaft, in parallel with the cylinder portion toward the front of the cylinder portion, and further, a locking projection is formed on the cylinder portion at an appropriate rear side of the rib. Then, the ribs of the eraser holder are inserted into the vertical grooves of the slits, and the locking projections can be engaged with and disengaged from the horizontal grooves of the slits, and the crown is formed integrally with the inner cylinder inside the outer cylinder. Then, the rear end of the shaft cylinder is engaged with the shaft cylinder in a state of being inserted between the outer cylinder and the inner cylinder.

According to a second aspect of the present invention, there is provided an eraser feeding device according to the first aspect, wherein a writing mechanism is connected to a connection portion at the front end of the barrel. .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the eraser feeding device of the present invention is characterized in that it is integrally connected to a rear portion of a writing instrument or the like. Further, the embodiment shown in the drawing shows an embodiment in which the writing instrument is a double writing instrument. The double-type writing instrument shown in the figure includes a center shaft 1 integrally provided with a guide cylinder 2, a front shaft 3, an eraser feeding device 4 integrally provided with a cylindrical cam 5, a pair of sliding pieces 6a and 6b, a mechanical pencil writing body 7, A writing body 8 such as a ballpoint pen is a main component. First, as shown in FIG. 1, the center shaft 1 is made of a resin, and has a guide groove 9a which is long in the axial direction and opens on the side surface from a substantially central portion to a rear end, and a guide groove 9b on the opposite side surface. A tube 2 is provided. The front half of the guide cylinder 2 is provided with a cylinder part 9 having a partition part 15 having holes 15a and 15b in communication with the respective guide grooves 9a and 9b and having an open front end. A stepped portion 31 is formed, and a bulging engagement portion 10 is formed on a front outer peripheral portion of the stepped portion 31.

As shown in FIG. 2, a vertical groove 17 is formed on the rear side surface of the center shaft 1 through a narrow surface 17a through an inclined surface 17a.
Are connected to the circumferential groove 18 to form a substantially inverted T-shaped window. As will be described later, the protrusion 16 of the cylindrical cam 5 is
The projection 16 elastically expands the inclined surface 17a, passes through the narrow portion 17b, and enters the circumferential groove 18. The cylindrical cam 5 rotates within a range in which the protrusion 16 abuts on both circumferential walls of the circumferential groove 18, and the writing portion of the writing body 8 such as a mechanical pencil 7 or a ballpoint pen alternately protrudes and retracts from the front end of the front shaft. become. In addition, the circumferential groove 18 is made of the mechanical pencil 7
A wide knock groove 19 is provided so that the cylindrical cam 5 can be axially shifted at the position of the projection 16 when the writing element projects, and the position of the projection 16 when the writing object is stored or when the writing object 8 such as a ball-point pen projects. A narrow groove 18c is provided between the rear wall 18b and the front wall 18a of the circumferential groove 18 so that the cylindrical cam 5 cannot move substantially in the axial direction.

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 10 provided on the outer peripheral portion of the cylindrical portion 9 of the guide cylinder so as to prevent the cylindrical portion 9 from slipping out and being prevented from rotating. . In addition, the cylindrical portion 9 and the front shaft 3
Is detachably fixed by an appropriate force.

The eraser feeding device 4 includes a shaft cylinder 4a, an eraser holder 37, an eraser 47, and a crown 36. The shaft cylinder 4a is made of resin and integrally has a cylindrical cam 5 at the tip. The cylindrical cam 5 has a cylindrical shape, and has a cam slope 13 which is displaced circumferentially back and forth at the front end edge.
A cutout 14 is formed at the foremost end of 3. On the side surface of the cylindrical cam 5, there is formed a projection 16 which is inserted into the vertical groove 18 of the center shaft 1 and elastically fits into the circumferential groove 18 to rotate and prevent it from falling within a certain range (approximately 180 degrees). .

A connecting portion (cylindrical cam 5) through which the eraser holder 37 cannot be inserted is formed at the front end of the barrel 4a, and a slit 32 is provided on the side surface of the barrel 4a in the axial direction. The slit 32 is provided with a narrow vertical groove 33 drilled to the rear end in the axial direction and a slightly wide horizontal groove 34 substantially perpendicular to the vertical groove 33 at a plurality of locations at appropriate intervals. Have been.

In the eraser holder 37, a plate-shaped slider 39 is integrally formed in parallel with the cylinder 38 toward the front of the cylinder 38 using a rib 39a standing on the side surface of the cylinder 38 at the rear end as a support shaft. Further, a locking projection 40 is formed on the cylindrical portion 38 at an appropriate rear side of the rib 39a. Also, the shaft cylinder 4a
When the slider 39 is pressed inward, the locking projection 40
A cut groove 37a and the like are formed in the cylindrical portion 38 such that the inward displacement occurs. A partition 37b is formed at the rear end of the cylindrical portion 38, and a cylindrical portion 41 for fixing the front end of the eraser 47 is formed behind the partition 37b.

As described above, the eraser holder 37 is attached to the shaft cylinder 4a.
The rib 39a is inserted into the vertical groove 33 of the slit 32, and the locking projection 40 is elastically detachable from the horizontal groove 34 of the slit. By sliding the slider 39 in the front-rear direction along the slit, the eraser holder 37 provided in the shaft cylinder 4a is moved back and forth so as to interlock with the slider 39, so that the eraser holder 3 is moved.
The rear end of the eraser 47 fixed to 7 can protrude and retract from the rear end of the barrel.

In order for the slider 39 to slide smoothly, it is necessary to increase the width of the rib 39a in the axial direction with respect to the width of the lateral groove 34 to prevent the rib from engaging with the lateral groove. However, when the rib 39a is small due to design reasons, it can be solved by providing a detent between the inner surface of the shaft cylinder and the outer periphery of the cylinder portion of the eraser holder. 4 and 5
Shows another embodiment in which the rib 40a is provided between the rib 39a and the locking projection 40, and this may be used.

By the way, a ridge 43 is formed on the outer periphery of the rear end of the shaft cylinder 4a.
5, an inner cylinder 44 is formed integrally with the outer cylinder 45,
A circumferential groove 46 is formed on the inner surface of the shaft, and the ridge 43 is elastically engaged with the groove 46 in a state where the outer peripheral portion of the rear end of the shaft cylinder 4a is inserted between the outer cylinder 45 and the inner cylinder 44. At the same time, the crown 36 is locked and fixed to the barrel 4a.

FIG. 6 shows an eraser feeding device 48 according to another embodiment. Explaining only the differences from the above-described embodiment, a protrusion 51 is formed at the center of an elastic piece whose both ends are supported at positions opposite to the position where the slider 49 of the cylindrical portion 50 is located, and the protrusion 51 is pressed. As a result, the locking projection 52 can be elastically engaged with and disengaged from the lateral groove of the slit.

FIG. 7 shows an eraser feeding device 53 according to still another embodiment. Explaining only the differences from the above-described embodiment, a protrusion 58 is formed at the other end of a cantilevered elastic piece having one end supported at a position opposite to the position where the slider 56 of the cylindrical portion 54 is located. Is pressed, the locking projection 55 can be elastically disengaged from the lateral groove of the slit.

On the other hand, the sliding piece 6a has a projection 22a on the outer surface, a central portion protruding from the rear end face of the projection 22a, and both sides thereof have a cam slope having substantially the same slope as the cam slope 13 of the cylindrical cam 5 described above. have. 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 6b has a projection 22b and a cam slope like the sliding piece 6a, and has a locking portion 26 at its tip for fastening the rear end of the writing body 8 such as a ball-point pen. 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 pipe 6a is fitted in contact with the sliding pipe 6a, and the core pipe 2 protrudes from the rear end of the sliding piece 6a.
3 is closed with a tail plug 25 or the like. The leading of the lead is performed by moving the chuck according to the axial movement of the sliding piece 6a in a state where the step 28 at the tip 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. For the writing body 8 such as a mechanical pencil 7 and a ballpoint pen, each sliding piece 6a, 6b is connected to the rear end, and each guide of the center axis guide tube 2 is connected. The return spring 3 is movably fitted in the grooves 9a, 9b, and is interposed between the front end surfaces of the sliding pieces 6a, 6b and the partition portions 15 on the front surfaces of the guide grooves 9a, 9b.
It is urged rearward by 0a, 30b. The eraser feeding device 4 inserts the cylindrical cam 5 into the rear end hole of the center shaft 1 to elastically fit the projection 16 into the circumferential groove 18, and is rotatable about 180 degrees in the circumferential direction with respect to the center shaft 1 and It stops and comes off. Further, the eraser feeding device 4 can shift the axis necessary for the center feeding with respect to the center shaft 1 in a state where the mechanical pencil 7 is protruded, and when the writing material is stored or the writing material 8 such as a ballpoint pen is projected. In this state, the axis transition is disabled. Since the sliding pieces 6a and 6b are always urged rearward by the return springs 30a and 30b, the cam slopes of the projections 22a and 22b are always kept in contact with the cam slope 13 of the cylindrical cam 5.

The engaging portion 10 of the cylindrical portion 9 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. In this state, when the eraser feeding device 4 is rotated in one direction with respect to the front shaft 3 or the center shaft 1, the sliding piece 6a moves forward and the cam slope 13 of the cylindrical cam 5 is moved.
Notch 14 at the forefront is one of the mechanical pencil 7
The writing tip is locked to the projection 22a of the sliding piece 6a so that the writing tip projects from the tip end of the front shaft. When the eraser feeding device 4 is rotated with respect to the front shaft 3 or the center shaft 1 in the other direction, the sliding piece 6a is retracted, and the writing tip of the mechanical pencil 7 penetrates from the tip of the front shaft, and slides. Top 6b
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, the eraser feeding device 4 includes a shaft cylinder 4
The eraser holder 37 is fitted from the rear end of the cylindrical portion of a,
The locking projection 40 of the eraser holder 37 is elastically engaged with the lateral groove 34 of the slit 32 provided in the barrel, and the eraser holder 37 is slidable with respect to the barrel. A crown 36 is fixed to the rear end of the barrel, and an eraser 4
Reference numeral 7 denotes an eraser holder 3 which is inserted through an opening at the rear end of the crown 36 (the inner hole of the inner cylinder 44 of the crown) and the rear end of the eraser 47 is erased.
7 is fixed to the cylindrical portion 41. As described above, when the eraser holder 37 is moved back and forth, the eraser 47 comes out of the opening of the crown 36. Note that the inner diameter of the opening of the crown 36 is provided slightly larger than the outer diameter of the eraser 47.

[0022]

When the eraser feeding device 4 is rotated in one direction with respect to the front shaft 3 or the center shaft 1, as shown in FIG.
The notch 14 provided at the tip of the cam slope 13 engages with the sliding piece 6a of one of the mechanical pencils 7 to protrude the writing tip from the tip end of the front shaft. At this time, the projection 16 of the cylindrical cam 5 is located at the knock groove 19 in the circumferential groove 18 of the center shaft 1. In this state, when the rear end of the crown 36 is knocked and the cylindrical cam 5 is shifted axially, the operation is transmitted to the sliding piece 6a, 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 eraser feeding device 4 is rotated with respect to the front shaft 3 or the center shaft 1 in the other direction, the writing pencil 7 of the mechanical pencil retreats, and instead the writing tip of the writing pencil 8 such as a ball-point pen projects from the tip end of the front spindle.

Next, when the slider 39 is retracted with respect to the eraser feeding device 4, the locking projection 40 is elastically separated from the lateral groove 34 of the slit 32 and moves, so that the eraser holder 37 is gradually retracted. The eraser 47 is paid out from the opening of the crown 36. Also, slider 3
9 is pushed forward, the eraser holder 37 advances, and the eraser 47 is immersed through the opening of the crown 36.

[0024]

As described above, the eraser feeding device of the present invention, which is integrally connected to the rear portion of a writing instrument or the like, has a simple structure, and the slider can be formed integrally with the eraser holder. Therefore, the number of parts is reduced compared to the conventional example, and the assembling is facilitated, so that it is possible to provide the device at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal cross-sectional view of a main part of an entire writing instrument showing an embodiment of the present invention.

FIG. 2 is a view showing a joining relationship between a cylindrical cam and a center shaft.

FIG. 3 is an external view of a main part showing a relationship between a slider and a slit.

FIG. 4 is a sectional view of a main part showing another embodiment of the slider.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a longitudinal cross-sectional view of a main part of the entire writing instrument, showing another embodiment of the eraser feeding device.

FIG. 7 is a longitudinal sectional view of a main part of the entire writing implement, showing a further alternative embodiment of the eraser feeding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Middle shaft 2 Guide cylinder 2a Guide groove 2b Guide groove 3 Front shaft 4 Eraser feeding device 4a Shaft cylinder 4b Clip 5 Cylindrical cam 6a Sliding piece 6b Sliding piece 7 Pencil writing body 8 Writing body such as ballpoint pen 9 Cylindrical part 10 Engagement Part 11 Knock spring 12 Engagement groove 13 Cam slope 14 Notch 15 Partition part 15a Hole 15b Hole 16 Projection 17 Vertical groove 17a Inclined surface 18 Peripheral groove 18a Front wall 18b Back wall 18c Narrow groove 19 Knock groove 20 Wall 21 Window 22a Projection 22b Projection 23 Core pipe 24 Flange 25 Tail plug 26 Locking portion 27 Inner step 28 Step 29 Joint 30a Return spring 30b Return spring 31 Step 32 Slit 33 Vertical groove 34 Horizontal groove 35 Locking step 36 Crown 37 Eraser holder 37a Groove 37b Partition 38 Cylinder 39 slider 39a rib 39b projection 40 locking projection 40a rib 41 cylinder 42 opening 43 projection ridge 44 inner cylinder 45 outer cylinder 46 groove 47 eraser 48 eraser feeding unit 48a shaft cylinder 49 slider 50 cylinder 51 projection 52 Stop projection 53 Eraser feeding device 53a Shaft cylinder 54 Tube section 55 Engagement projection 56 Slider 57 Elastic piece 58 Projection

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[Procedure amendment]

[Submission date] April 9, 1999 (1999.4.9)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG.

FIG. 6

FIG. 7

Claims (2)

[Claims] A slit is provided in an axial direction on a side surface of a shaft cylinder, and a slider provided through the slit is slid in the front-rear direction along the slit, so that the shaft cylinder is interlocked with the slider. An eraser feeding device provided such that an eraser holder provided therein is moved back and forth so that a rear end of the eraser fixed to the eraser holder protrudes and retracts from a rear end of the shaft cylinder. The front end has a connection portion through which the eraser holder cannot be inserted, and the slit has a narrow vertical groove perforated to the rear end in the axial direction longitudinally and slightly perpendicular to the vertical groove. Wide transverse grooves are provided at a plurality of locations at appropriate intervals, and the eraser holder is integrally formed with a plate-shaped slider in front of the cylinder portion using a rib standing on the side surface of the rear cylinder portion as a support shaft. Toward the cylinder It is formed in parallel, and furthermore, a locking projection is formed on the cylinder part appropriately behind the rib, and the rib of the eraser holder is inserted into the vertical groove of the slit, and the locking projection can be engaged and disengaged with the horizontal groove of the slit. Made
The crown has an inner cylinder integrally formed inside the outer cylinder, and is locked to the shaft cylinder in a state where the rear end of the shaft cylinder is inserted between the outer cylinder and the inner cylinder. An eraser feeding device, characterized in that: 2. The eraser feeding device according to claim 1, wherein a writing mechanism portion is connected to the connection portion at the front end of the barrel.