Multiple refill type writing instrument

Abstract

To provide a multiple refill type writing instrument which can easily switch refills that write.SOLUTION: A multiple refill type writing instrument 1 includes a barrel 2, an operating member 20 which is provided to be movable in the front-rear direction with respect to the barrel 2, multiple refills 5 and a rotating member 30 which is provided to be able to rotate around the central axis with respect to the barrel 2 while holding the multiple refills 5, in which the operating member 20 and the rotating member 30 move harmoniously in response to the front-rear movements of the operating member 20 to rotate the rotating member 30, and as a result one of the multiple refills 5 moves forward.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a multi-core writing instrument. [Background technology]

[0002] Multi-core writing instruments that are provided with a plurality of refills and allow a desired refill to be selectively protruded and retracted are known (Patent Documents 1 and 2).

[0003] In the multi-core writing instrument described in Patent Document 1, a plurality of operating parts (sliding bodies) are arranged along the circumferential direction on the side of the barrel. Each of the operating parts is movable in the front-rear direction. A plurality of refills are arranged inside the barrel, and each of the refills is connected to a corresponding operating part. By advancing the operating part corresponding to the desired refill, the refill can be brought into a writing state. Therefore, when switching the refill to be used while writing, the writing is first interrupted and the barrel is gripped again, the position of the corresponding operating part corresponding to the desired refill is confirmed, and then the operating part is advanced.

[0004] In the multi-core writing instrument described in Patent Document 2, a window hole is formed in the portion where the fingertip comes into contact during writing, and an operating shaft, which is an operating part, protrudes radially from the window hole. In the multi-core writing instrument described in Patent Document 2, two refills can be selectively inserted and removed. When switching from a non-writing state to a writing state, first, the operating shaft is rotated in a direction corresponding to the desired refill (tentatively referred to as the "first direction"), then the operating shaft is advanced, and then the operating shaft is rotated in the first direction to engage with the locking part, thereby entering the writing state. In addition, when switching the refill to be written with during writing, first, the operating shaft is rotated in a direction opposite to the first direction (tentatively referred to as the "second direction"), then the operating shaft is retreated, then the operating shaft is further rotated in the second direction, then the operating shaft is advanced, and then the operating shaft is rotated in the second direction to engage with the locking part, thereby entering the writing state. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-049192 A [Patent Document 2] JP 2001-219690 A Summary of the Invention [Problem to be solved by the invention]

[0006] With the multi-core writing instrument described in Patent Document 1, each time a refill is changed, it is necessary to change the grip of the multi-core writing instrument, confirm the position of the operating part corresponding to the desired refill, and move the operating part forward, which are bothersome actions. With the multi-core writing instrument described in Patent Document 2, when switching from a non-writing state to a writing state, and when switching the refill to be written with in the writing state, complex finger movements are required, which are also bothersome actions.

[0007] An object of the present invention is to provide a multi-core writing instrument that allows easy switching of refills to be used for writing. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a multi-core writing instrument comprising a barrel, a first operating part provided so as to be movable in the front-rear direction relative to the barrel, a plurality of writing bodies, and a rotating member provided so as to be rotatable about a central axis relative to the barrel while holding the plurality of writing bodies, wherein the first operating part and the rotating member cooperate to rotate the rotating member in response to the front-rear movement of the first operating part, thereby moving one of the plurality of writing bodies forward. Note that in the axial direction of the multi-core writing instrument, the writing part side is defined as the "front" side, and the opposite side to the writing part is defined as the "rear" side.

[0009] The pen may further include a cam surface, and one of the writing bodies may be advanced by cooperation between the writing bodies and the cam surface in response to the rotation of the rotating member. A cam groove may be formed on one of the first operating part and the rotating member, and a cam protrusion may be formed on the other of the first operating part and the rotating member, and the cam groove and the cam protrusion may be formed to rotate the rotating member by cooperation between them. The cam groove may be formed in a spiral shape around a central axis. The pen may further include a second operating part, and the writing body that has advanced may be made to appear and disappear from the barrel by a knock operation that presses the second operating part forward. All or a part of the first operating part or the second operating part may be an erasing part that can erase handwriting of the multi-core writing instrument. The first operating part may be disposed in the front half of the barrel. Effect of the Invention

[0010] According to the aspects of the present invention, a common effect is achieved in that a multi-core writing instrument that allows easy switching of the refill to be used for writing is provided. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a multi-core writing instrument according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the multi-core writing instrument in a non-writing state. [Diagram 3] FIG. 3 is a vertical cross-sectional view of the multi-core writing instrument in a writing state. [Figure 4] FIG. 4 is a vertical cross-sectional view of the multi-core writing instrument in a writing state during refill switching. [Diagram 5] FIG. 5 is a vertical cross-sectional view of the multi-core writing instrument in a writing state after switching of refills. [Figure 6] FIG. 6 is a vertical cross-sectional view of the rear axle. [Figure 7] FIG. 7 is a perspective view of the operating member. [Figure 8] FIG. 8 is a side view of the operating member. [Figure 9]FIG. 9 is a perspective view of the rotating member. [Figure 10] FIG. 10 is a vertical cross-sectional view of the rotating member. [Figure 11] FIG. 11 is a perspective view of the slide cam. [Figure 12] FIG. 12 is a vertical cross-sectional view of the slide cam. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Corresponding components throughout the drawings are designated by common reference numerals.

[0013] Fig. 1 is a perspective view of a multi-core writing instrument 1 according to an embodiment of the present invention. Fig. 2 is a vertical cross-sectional view of the multi-core writing instrument 1 in a non-writing state, Fig. 3 is a vertical cross-sectional view of the multi-core writing instrument 1 in a writing state, Fig. 4 is a vertical cross-sectional view of the multi-core writing instrument 1 in a writing state during refill switching, and Fig. 5 is a vertical cross-sectional view of the multi-core writing instrument 1 in a writing state after refill switching.

[0014] The multi-core writing instrument 1 has a barrel 2, which is a cylindrical member formed in a cylindrical shape. The barrel 2 is composed of a front barrel 3, a center barrel 4, and a rear barrel 10. In addition, a plurality of refills 5, specifically two refills 5, are arranged in the barrel 2 as writing bodies having a writing part 5a at one end. The two refills 5 are referred to as refills 5A and 5B when distinguishing between them. Each of the two refills 5 is independently biased backward by a corresponding spring 6 as an elastic member. The multi-core writing instrument 1 further has an operating member 20, which is a first operating part, a rotating member 30, a slide cam 40, a knock member 50, which is a second operating part, a rotor 60, and a sliding top 70. In this specification, in the axial direction of the multi-core writing instrument 1, the writing part 5a side is defined as the "front" side, and the opposite side to the writing part 5a is defined as the "rear" side. Unless otherwise specified, the central axis or axial direction refers to the central axis or axial direction of the multi-core writing instrument 1.

[0015] The multi-core writing instrument 1 is a knock-type writing instrument in which the refill 5 appears and disappears from the barrel 2 by a knock operation of pressing the knock member 50 forward. That is, by a knock operation of pressing the knock member 50 forward, the refill 5, which is moving forward relatively, specifically the refill 5A in FIG. 2 appears and disappears from the end face of the barrel 2.

[0016] Generally, a knock-type writing instrument has a rotor. A protruding cam portion is provided on the outer peripheral surface of the rotor, and a protruding cam portion that cooperates with the cam portion of the rotor is provided on the inner peripheral surface of the barrel. By knocking, the cam portion of the rotor and the cam portion of the barrel are engaged or disengaged, thereby switching between a writing state and a non-writing state.

[0017] In this embodiment, a cam portion 11, which will be described later, is formed on the inner peripheral surface of the rear end of the rear barrel 10 of the barrel 2. The knock operation is performed by pressing the knock member 50 forward and moving the rotor 60 together with the knock member 50 forward to a predetermined position in the barrel 2. That is, in order for the cam portion (not shown) of the rotor 60 to engage with the cam portion 11 of the barrel 2, the rotor 60 is moved to a predetermined position where the rear end face of the cam portion of the rotor 60 is located at least axially forward of the front end face of the cam portion 11 of the barrel 2. After the rotor 60 has been moved to the predetermined position, the force applied to the knock member 50 is released, and the rotor 60 rotates and moves back slightly due to the biasing force of the spring 6, and the rear end face of the cam portion of the rotor 60 engages with the front end face of the cam portion 11 of the barrel 2, and the multi-core writing instrument 1 is in a writing state (FIG. 3).

[0018] In the writing state, when the knock member 50 is pressed forward by a knock operation and the rotor 60 is moved forward again to a predetermined position, the rear end face of the cam portion of the rotor 60 is disengaged from the front end face of the cam portion 11 of the barrel 2, and the rotor 60 rotates. When the force applied to the knock member 50 is then released, the biasing force of the spring 6 moves the rotor 60 further backward, and the multi-core writing instrument 1 returns to the non-writing state (FIG. 2).

[0019] The configuration of the main parts will be described with reference to FIGS. 6 to 11 as appropriate.

[0020] FIG. 6 is a vertical cross-sectional view of rear barrel 10. In the assembled state of multi-core writing instrument 1, rear barrel 10 is arranged so that the upper side in FIG. 6 is the rear side of multi-core writing instrument 1. Rear barrel 10 is a cylindrical member formed in a cylindrical shape. A rectangular concave-convex shape is formed on the front end face of rear barrel 10. The concave-convex shape on the front end face of rear barrel 10 fits into and is joined to a complementarily formed concave-convex shape (FIG. 1) on the rear end face of center barrel 4. A cam portion 11 is formed on the inner peripheral surface of the rear end of rear barrel 10. Cam portion 11 is made of a plurality of protrusions 12 extending in the axial direction, and as described above, engages or disengages with the cam portion of rotor 60 during knocking operation. Two slide grooves 13 extending rearward from the front end and arranged opposite each other are formed on the inner peripheral surface of rear barrel 10. The inner circumferential surface of the rear of the front end of the rear axle 10 is formed with a smaller diameter than the inner circumferential surface of the front end, and is formed with a first annular step portion 14 facing forward. Also, the inner circumferential surface in front of the cam portion 11 is formed with a second annular step portion 15 facing forward. A first through hole 16a arranged on the front side and a second through hole 16b arranged on the rear side are formed in the peripheral surface of the rear axle 10 along the axial direction.

[0021] FIG. 7 is a perspective view of the operating member 20, and FIG. 8 is a side view of the operating member 20. In the assembled state of the multi-core writing instrument 1, the operating member 20 is arranged so that the upper side in FIG. 7 and FIG. 8 is the rear side of the multi-core writing instrument 1. The operating member 20 is a cylindrical member formed in a cylindrical shape. An operating protrusion 21 is formed on the outer peripheral surface of the front end of the operating member 20. On both sides of the operating protrusion 21 in the circumferential direction of the operating member 20, two slits 22 extending in parallel from the front end toward the rear are formed. On the peripheral surface of the operating member 20, a cam groove 23 is formed in a spiral shape around the central axis. The spiral cam groove 23 is formed clockwise from the vicinity of the rear end toward the front by approximately half a turn when the operating member 20 is viewed from the rear. On the peripheral surface of the operating member 20, one slit 24 extending from the rear end toward the front is formed.

[0022] FIG. 9 is a perspective view of the rotating member 30, and FIG. 10 is a vertical cross-sectional view of the rotating member 30. In the assembled state of the multi-core writing instrument 1, the rotating member 30 is arranged so that the upper side in FIG. 9 and FIG. 10 is the rear side of the multi-core writing instrument 1. The rotating member 30 is composed of a cylindrical small diameter portion 31 located at the front side, a cylindrical large diameter portion 32 formed behind the small diameter portion 31, and a columnar sliding portion 33 formed behind the large diameter portion 32. One cam protrusion 34 is formed on the outer circumferential surface of the small diameter portion 31. The cross-sectional shape of the cam protrusion 34 is an ellipse or a rounded rectangle. The cam protrusion 34 is oriented so as to follow the extension direction of the cam groove 23 arranged as described later. The cam protrusion 34 may be circular. The insides of the large diameter portion 32 and the sliding portion 33 are equally separated by a partition wall 35 extending in the axial direction in order to arrange the two refills 5 at a distance from each other. Furthermore, inside the large diameter portion 32, two insertion holes 36 extending in the axial direction are formed at symmetrical positions with the partition wall 35 in between. A support surface 37 facing rearward is formed on the inner peripheral surface of each of the insertion holes 36. Two rail grooves 38, which are rectangular through-holes extending in the axial direction, are formed on the peripheral surface of the sliding portion 33 at symmetrical positions with the partition wall 35 in between.

[0023] FIG. 11 is a perspective view of the slide cam 40, and FIG. 12 is a vertical cross-sectional view of the slide cam 40. In the assembled state of the multi-core writing instrument 1, the slide cam 40 is arranged so that the upper side in FIG. 11 is the rear side of the multi-core writing instrument 1. The slide cam 40 has an annular portion 41 formed in an annular shape around the central axis, and a claw portion 42 having a claw shape. A flat surface 43 formed flat and a slanted end surface 44 formed obliquely are formed on the edge of the claw portion 42. The flat surface 43 and the slanted end surface 44 of the claw portion 42 and the front end surface 45 of the annular portion 41 constitute a cam surface 46. Two slide protrusions 47 extending in the axial direction are formed on the outer peripheral surface of the annular portion 41. The two slide protrusions 47 are formed symmetrically around the central axis. The inner peripheral surface near the rear end of the annular portion 41 protrudes in an annular shape, thereby forming an annular support surface 48 facing backward.

[0024] Next, the combination and arrangement of each part in the multi-core writing instrument 1 will be described mainly with reference to FIGS.

[0025] The front shaft 3 is fitted to the front end of the center shaft 4. The rotating member 30 is arranged in the shaft tube 2 so that the front end surface of the small diameter portion 31 faces the rear end surface of the front shaft 3, and the rear end surface of the large diameter portion 32 of the rotating member 30 faces the first step portion 14 of the rear shaft 10. As a result, the rotating member 30 is arranged in the shaft tube 2 so that it can rotate around the central axis while its axial movement is restricted. The rear portion of the front shaft 3 is formed in a cylindrical shape having approximately the same outer diameter and inner diameter as the small diameter portion 32 of the rotating member 30. The operating member 20 is arranged over both the outer surface of the rear portion of the front shaft 3 and the outer surface of the small diameter portion 32 of the rotating member 30. At this time, the cam protrusion 34 of the rotating member 30 is arranged in the cam groove 23 of the operating member 20. In addition, the operating protrusion 21 of the operating member 20 protrudes to the outside of the shaft tube 2 through a window hole 4a formed on the circumferential surface of the center shaft 4. The window hole 4a is a rectangular through hole extending in the axial direction. The operating protrusion 21 abuts against the inner edge of the window hole 4a, thereby restricting the forward and backward movement of the operating member 20 within a predetermined distance range, and also restricting the rotation about the central axis of the operating member 20. When the operating member 20 is placed inside the barrel 2, the slits 22 and 24 formed in the operating member 20 enable elastic deformation in the radial direction, making it easy to place.

[0026] Each of the two refills 5 is inserted into the corresponding insertion hole 36 of the rotating member 30 and separated by the partition wall 35. A sliding top 70 is inserted into the rear end of the refill 5, and the sliding top 70 is connected to the refill 5 by fitting. The sliding top 70 connected to the refill 5 fits into the rail groove 38 of the rotating member 30 and is arranged to be slidable in the axial direction without falling off. The rear end of the sliding part 33 of the rotating member 30 is received in the front part of the slide cam 40. Each of the slide protrusions 47 of the slide cam 40 is arranged in the corresponding slide groove 13 of the rear shaft 10. Thereby, the slide cam 40 is arranged to be slidable in the axial direction without rotating around the central axis.

[0027] The spring 6 is disposed in the insertion hole 36 of the rotating member 30. At this time, the front end of the spring 6 is supported by the support surface 37 of the rotating member 30, and the rear end of the spring 6 abuts against the sliding top 70. As a result, the spring 6 urges the sliding top 70 backward, and in turn urges the refill 5 connected to the sliding top 70 backward. In addition, the rear end of the sliding top 70 abuts against the cam surface 46 of the slide cam 40. Therefore, the spring 6 also urges the slide cam 40 backward via the sliding top 70. In the non-writing state of the multi-core writing instrument 1 (FIG. 2), the rearward movement of the slide cam 40 urged backward is restricted by the support surface 48 of the slide cam 40 abutting against the front end surface of the rotor 60, or by the rear end surface of the slide cam 40 abutting against the second step portion 15 of the rear shaft 10. Furthermore, when the multi-core writing instrument 1 is in the writing state (FIG. 3), the rearward movement of the rearwardly biased slide cam 40 is restricted by the support surface 48 of the slide cam 40 abutting against the front end surface of the rotor 60.

[0028] Next, the operation of the multi-core writing instrument 1 will be described.

[0029] As described above, in the multi-core writing instrument 1, the operating member 20, which is the first operating part, specifically the operating protrusion 21, is provided so as to be movable in the front-rear direction relative to the barrel 2. The multi-core writing instrument 1 is configured so that the operating member 20 and the rotating member 30 cooperate to rotate the rotating member 30 in response to the front-rear movement of the operating member 20, thereby moving one of the multiple refills 5 forward. In other words, the front-rear movement of the operating member 20 is converted into the rotational movement of the rotating member 30, and the rotational movement of the rotating member 30 is converted into the front-rear movement of the refill 5.

[0030] In the state shown in FIG. 2 and FIG. 3, the refill 5A is in a position further forward than the refill 5B. That is, the sliding top 70 to which the refill 5A is connected is disposed on the flat surface 43 of the claw portion 42 on the cam surface 46 of the slide cam 40. On the other hand, the sliding top 70 to which the refill 5B is connected is disposed on the front end surface 45 of the annular portion 41 on the cam surface 46 of the slide cam 40. Therefore, the refill 5A is relatively further forward than the refill 5B. Therefore, in the non-writing state shown in FIG. 2, when the knock member 50, which is the second operating part, is knocked, the refill 5A and the refill 5B advance together with the rotor 60 and the slide cam 40. As a result, only the refill 5A, which has relatively advanced, protrudes from the barrel 2, and the writing state is established (FIG. 3). Note that the knock operation does not move the operating member 20 and the rotating member 30 in the axial direction.

[0031] In the state shown in FIG. 3, the operation protrusion 21 of the operation member 20 is disposed at the front end in the window hole 4a, and the cam protrusion 34 of the rotating member 30 is disposed at the rear end in the cam groove 23 of the operation member 20. In this state, when the operation protrusion 21 of the operation member 20 is moved backward, the cam protrusion 34 moves relatively forward along the spiral track of the cam groove 23. This causes the rotating member 30 to rotate around the central axis (FIG. 4). At this time, the refill 5 and the sliding top 70 rotate around the central axis together with the rotating member 30 while being biased backward by the spring 6. As a result, each of the sliding tops 70 moves in the circumferential direction along the cam surface 46 of the slide cam 40. Therefore, the sliding top 70 connected to the refill 5A moves from the flat surface 43 of the claw portion 42 along the inclined end surface 44 toward the front end surface 45 of the annular portion 41 on the cam surface 46 of the slide cam 40. On the other hand, the sliding top 70 to which the refill 5B is connected moves on the cam surface 46 of the slide cam 40 from the front end surface 45 of the annular portion 41 along the inclined end surface 44 toward the flat surface 43 of the claw portion 42 .

[0032] When the operation protrusion 21 of the operation member 20 is further moved backward until it reaches the rear end in the window hole 4a, the cam protrusion 34 of the rotating member 30 reaches the front end in the cam groove 23 of the operation member 20. This completes the rotation around the central axis of the rotating member 30, specifically, a 180-degree rotation. That is, the sliding top 70 to which the refill 5A is connected is disposed on the front end surface 45 of the annular portion 41 on the cam surface 46 of the slide cam 40. On the other hand, the sliding top 70 to which the refill 5B is connected is disposed on the flat surface 43 of the claw portion 42 on the cam surface 46 of the slide cam 40. Therefore, the refill 5B moves forward relatively more than the refill 5A and protrudes from the barrel 2, and is in a writing state (FIG. 5).

[0033] In the state shown in FIG. 5, when writing again with refill 5A, the operation protrusion 21 of the operation member 20 is moved forward. By moving the operation protrusion 21 backward, the cam protrusion 34 moves relatively backward along the spiral track of the cam groove 23. This causes the rotating member 30 to rotate about the central axis in the opposite direction to the previous rotation (FIG. 4). As a result, the refill 5A moves forward relatively more than the refill 5B and protrudes from the barrel 2, and the writing state is reached (FIG. 3). Note that, although the switching of the refill 5 in the writing state of the multi-core writing instrument 1 has been described with reference to FIGS. 3 to 5, the switching of the refill 5 can also be performed in a similar manner when the multi-core writing instrument 1 is in a non-writing state.

[0034] Next, the operation of the multi-core writing instrument 1 by a user will be specifically described. A user usually holds the center shaft 4 of the multi-core writing instrument 1 with the thumb, index finger, and middle finger and writes. At this time, the multi-core writing instrument 1 is held so that the operation protrusion 21 of the operation member 20 is positioned between the thumb and index finger. When switching refills, the user supports the multi-core writing instrument 1 with the index finger and middle finger and slides or flicks the operation protrusion 21 forward or backward with the thumb. After that, the user can write by returning the thumb to its original position and holding the multi-core writing instrument 1.

[0035] Therefore, the multi-core writing instrument 1 allows the user to easily switch between refills to be used. In particular, it is preferable that the first operating portion, i.e., the operating member 20 or the operating protrusion 21, is located in the front half of the barrel 2 so that it is easy to operate with the thumb. Furthermore, the multi-core writing instrument 1 allows the user to switch between refills to be used while writing without having to stop writing and change the grip of the barrel 2. Furthermore, the user can easily determine whether the refill 5A or the refill 5B is in the advanced position by looking at or touching the position of the operating protrusion 21 within the window hole 4a.

[0036] In addition, the user can determine whether the refill 5A or the refill 5B is in the forward position by checking the inside of the barrel 2 through the first through hole 16a and the second through hole 16b formed in the rear barrel 10. For this purpose, a sliding top 70 colored in the same color as the ink contained in the connected refill 5 is used. For example, in the state shown in FIG. 2, the sliding top 70 of the refill 5A is visible through the first through hole 16a and the second through hole 16b. Therefore, the user can determine that the refill 5A protrudes from the barrel 2 when performing a knock operation in this state. Also, in the writing state shown in FIG. 3, the sliding top 70 of the refill 5A is visible only through the first through hole 16a. Therefore, the user can determine that the refill 5A protrudes from the barrel 2. On the other hand, in the state shown in FIG. 5, the sliding top 70 of the refill 5B is visible only through the first through hole 16a. Therefore, the user can tell that the refill 5B is protruding from the barrel 2.

[0037] In the above-described embodiment, the multi-core writing instrument 1 is a knock-type writing instrument, but it may be configured as a writing instrument that can switch the refill 5 protruding from the barrel 2 without performing a knock operation. That is, the knock member 50 and the rotor 60 are eliminated from the multi-core writing instrument 1, and the slide cam 40 is fixed at the position shown in Figs. 3 to 5. In this case, the slide cam 40 may be formed integrally with the barrel 2. In the multi-core writing instrument configured in this manner, as shown in Fig. 4, when the operation protrusion 21 is disposed at the intermediate position in the front-rear direction of the window hole 4a, the multi-core writing instrument can be in a non-writing state. When the operation protrusion 21 is moved forward from this state, the refill 5A can be protruded from the barrel 2, and when the operation protrusion 21 is moved backward, the refill 5B can be protruded from the barrel 2, and the multi-core writing instrument can be in a writing state.

[0038] In the above-described embodiment, the cam groove 23 is formed in the operating member 20 and the cam protrusion 34 is formed in the rotating member 30, but a cam protrusion protruding radially inward may be formed in the operating member and a cam groove may be formed in the rotating member. That is, any configuration may be adopted as long as a cam groove is formed in one of the first operating part and the rotating member and a cam protrusion is formed in the other of the first operating part and the rotating member, and the first operating part and the rotating member cooperate with each other by the cam groove and the cam protrusion. In addition, any configuration may be adopted for the shape of the cam groove as long as the forward and backward movement of the first operating part is converted into the rotational movement of the rotating member.

[0039] In the above-mentioned embodiment, the multi-core writing instrument 1 has two refills 5, but may have three or more refills. The number of insertion holes of the rotating member, the shape of the partition, and the shape of the cam surface of the slide cam can be arbitrarily configured according to the number of refills. That is, the position and shape of the claw portion of the cam surface of the slide cam can be configured so that one of the multiple refills advances by cooperation between the multiple refills and the cam surface in response to the rotation of the rotating member. At this time, the position of the operation protrusion and the protruding refill, that is, the position of the cam protrusion in the cam groove and the protruding refill, are in a corresponding relationship. In the above-mentioned embodiment, since there were two refills, when the operation protrusion 21 is at the front end and the rear end in the window hole 4a, one refill is configured to protrude from the barrel 2. For example, when there are three refills, when the operation protrusion 21 is at the front end, the center, or the rear end in the window hole 4a, one of the three refills can be configured to protrude.

[0040] The refill 5 described above may be a ballpoint pen refill, or may be other types of refills such as mechanical pencils, marking pens, touch pens, erasers, or friction bodies. In addition, the entirety of the operation member 20, which is the first operation part, or a part of the operation member 20 may be bonded or molded in two colors to make the operation member 20 an erasing member that erases handwriting made by the refill 5. In addition, the entirety of the knock member 50, which is the second operation part, or a part of the knock member 50 may be bonded or molded in two colors to make the knock member 50 an erasing member that erases handwriting made by the refill 5. In addition, other parts of the multi-core writing instrument 1, such as the front end of the front shaft 3, may be used as an erasing member.

[0041] The refill may be a ballpoint pen containing thermochromic ink, a mechanical pencil containing a thermochromic core, or the like. In this case, the multi-core writing instrument 1 is a thermochromic writing instrument, and the handwriting can be thermochromic due to frictional heat generated when rubbed by a friction body that is an erasing member. Here, the thermochromic ink refers to an ink that has the property of maintaining a predetermined color (first color) at room temperature (e.g., 25°C), changing to another color (second color) when heated to a predetermined temperature (e.g., 60°C), and then returning to the original color (first color) when cooled to a predetermined temperature (e.g., -5°C). In a writing instrument using thermochromic ink, the second color is made colorless, and the term "erasing" refers to heating a line written in the first color (e.g., red) to make it colorless. Therefore, the friction body as the erasing part rubs against the writing surface on which the drawn lines have been drawn to generate frictional heat, thereby changing the drawn lines to colorless, that is, erasing them. It should be noted that the second color may of course be a color other than colorless.

[0042] The thermochromic microencapsulated pigment that serves as the thermochromic colorant is not particularly limited as long as it has the function of changing color due to heat such as frictional heat, for example, from colored to colorless, from colored to colored, or from colorless to colored, and various types can be used. Examples of the thermochromic microencapsulated pigment include a thermochromic composition that contains at least a leuco dye, a color developer, and a color change temperature regulator.

[0043] The leuco dye that can be used is not particularly limited as long as it is an electron donating dye and functions as a color former. Specifically, from the viewpoint of obtaining an ink having excellent color development characteristics, conventionally known dyes such as triphenylmethane, spiropyran, fluoran, diphenylmethane, rhodamine lactam, indolylphthalide, and leucoauramine can be used alone (one type) or in a mixture of two or more types (hereinafter simply referred to as "at least one type").

[0044] Specifically, 6-(dimethylamino)-3,3-bis[4-(dimethylamino)phenyl]-1(3H)-isobenzofuranone, 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-diethylaminophenyl)-3-(1-ethyl-2-methylindol-3-yl)phthalide, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindol-3-yl)- 4-Azaphthalide, 1,3-dimethyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-dimethylaminofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-xylidinofluoran, 2-(2-chloroanilino)-6-dibutylaminofluoran, 3,6-dimethoxyfluoran, 3,6- Di-n-butoxyfluoran, 1,2-benz-6-diethylaminofluoran, 1,2-benz-6-dibutylaminofluoran, 1,2-benz-6-ethylisoamylaminofluoran, 2-methyl-6-(Np-tolyl-N-ethylamino)fluoran, 2-(N-phenyl-N-methylamino)-6-(Np-tolyl-N-ethylamino)fluoran, 2-(3'-trifluoromethylanilino)-6-diethylamino nofluoran, 3-chloro-6-cyclohexylaminofluoran, 2-methyl-6-cyclohexylaminofluoran, 3-di(n-butyl)amino-6-methoxy-7-anilinofluoran, 3,6-bis(diphenylamino)fluoran, methyl-3',6'-bisdiphenylaminofluoran, chloro-3',6'-bisdiphenylaminofluoran, 3-methoxy-4-dodecoxystyrinoquinoline, and the like.

[0045] These leuco dyes have a lactone skeleton, a pyridine skeleton, a quinazoline skeleton, a bisquinazoline skeleton, or the like, and develop color by opening these skeletons (rings).

[0046] The color developer that can be used is a component that has the ability to cause the above-mentioned leuco dye to develop color, and examples thereof include phenolic resin-based compounds, salicylic acid metal chlorides, salicylic acid resin-based metal salt compounds, solid acid-based compounds, etc.

[0047] Specifically, o-cresol, tertiary butyl catechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, hexafluorobisphenol, n-butyl p-hydroxybenzoate, n-octyl p-hydroxybenzoate, resorcin, dodecyl gallate, 2,2-bis(4'-hydroxyphenyl)propane, 4,4-dihydroxydiphenyl sulfone, 1,1-bis(4'-hydroxyphenyl)ethane, 2,2-bis(4'-hydroxy-3-methylphenyl)propane, bis(4-hydroxyphenyl)sulfide, 1-phenyl-1,1-bis( 1,1-bis(4'-hydroxyphenyl)ethane, 1,1-bis(4'-hydroxyphenyl)-3-methylbutane, 1,1-bis(4'-hydroxyphenyl)-2-methylpropane, 1,1-bis(4'-hydroxyphenyl)n-hexane, 1,1-bis(4'-hydroxyphenyl)n-heptane, 1,1-bis(4'-hydroxyphenyl)n-octane, 1,1-bis(4'-hydroxyphenyl)n-nonane, 1,1-bis(4'-hydroxyphenyl)n-decane, 1 ,1-bis(4'-hydroxyphenyl)n-dodecane, 2,2-bis(4'-hydroxyphenyl)butane, 2,2-bis(4'-hydroxyphenyl)ethyl propionate, 2,2-bis(4'-hydroxyphenyl)-4-methylpentane, 2,2-bis(4'-hydroxyphenyl)hexafluoropropane, 2,2-bis(4'-hydroxyphenyl)n-heptane, and 2,2-bis(4'-hydroxyphenyl)n-nonane may be mentioned.

[0048] The amount of the developer used may be selected arbitrarily depending on the desired color density, and is not particularly limited; however, it is usually preferable to select the amount within the range of about 0.1 to 100 parts by mass per 1 part by mass of the above-mentioned leuco dye.

[0049] The discoloration temperature regulator that can be used is a substance that controls the discoloration temperature in the coloring of the leuco dye and the color developer. The discoloration temperature regulator that can be used is a conventionally known one. Specific examples of the discoloration temperature regulator that can be used include alcohols, esters, ketones, ethers, acid amides, azomethines, fatty acids, and hydrocarbons.

[0050] More specifically, bis(4-hydroxyphenyl)phenylmethane dicaprylate (C 15 ), bis(4-hydroxyphenyl)phenylmethane dilaurate (C 11 H 23 ), bis(4-hydroxyphenyl)phenylmethane dimyristate (C 13 H 27 ), bis(4-hydroxyphenyl)phenylethane dimyristate (C 13 H 27 ), bis(4-hydroxyphenyl)phenylmethane dipalmitate (C 15 H 30 ), bis(4-hydroxyphenyl)phenylmethane dibehenate (C 21 H 43 ), bis(4-hydroxyphenyl)phenylethylhexylidene dimyristate (C 13 H 27 ) and the like.

[0051] The amount of the discoloration temperature regulator used may be appropriately selected depending on the desired hysteresis width and color density at the time of color development, and is not particularly limited. However, it is usually preferable to use it in the range of about 1 to 100 parts by mass per 1 part by mass of the leuco dye.

[0052] The thermochromic microencapsulated pigment can be produced by microencapsulating a thermochromic composition containing at least the above-mentioned leuco dye, color developer, and color-changing temperature regulator so that the average particle size is 0.2 to 5 μm. Examples of the microencapsulation method include an interfacial polymerization method, an interfacial polycondensation method, an in situ polymerization method, a liquid hardening coating method, a phase separation method from an aqueous solution, a phase separation method from an organic solvent, a melting dispersion cooling method, an air suspension coating method, and a spray drying method, and can be appropriately selected depending on the application.

[0053] For example, in the phase separation method from an aqueous solution, the leuco dye, developer, and discoloration temperature regulator are heated and melted, then added to an emulsifier solution, and heated and stirred to disperse them into oil droplets. Next, a resin raw material or the like is used as an encapsulation membrane agent, for example, an amino resin solution, an isocyanate resin solution, etc. is gradually added, and the mixture is allowed to react to prepare the desired thermochromic microcapsule pigment, by filtering the dispersion.

[0054] The contents of these leuco dye, developer, and discoloration temperature regulator vary depending on the types of leuco dye, developer, and discoloration temperature regulator used, the microencapsulation method, etc., but the mass ratio of the developer to the dye is 0.1 to 100, and the mass ratio of the discoloration temperature regulator to the dye is 1 to 100. The mass ratio of the capsule membrane agent to the capsule contents is 0.1 to 1.

[0055] By appropriately combining the types and amounts of the above-mentioned leuco dye, developer, and discoloration temperature regulator, the thermochromic microcapsule pigment can be set to an appropriate temperature for each color's color development temperature (e.g., color development at 0°C or higher) and color loss temperature (e.g., color loss at 50°C or higher), and it is preferable that the thermochromic microcapsule pigment changes from colored to colorless due to heat such as frictional heat.

[0056] In the case of the thermochromic microcapsule pigment, in order to further improve the line density, storage stability, and writing ability, it is preferable that the wall film is formed of a urethane resin, a urea / urethane resin, an epoxy resin, or an amino resin. Examples of the urethane resin include a compound of an isocyanate and a polyol. Examples of the epoxy resin include a compound of an epoxy resin and an amine. Examples of the amino resin include a melamine resin, a urea resin, and a benzoguanamine resin. The thickness of the wall film of the microcapsule color material is appropriately determined according to the required strength of the wall film and the line density.

[0057] The average particle size of the thermochromic microencapsulated pigment is preferably 0.2 to 5 μm, more preferably 0.3 to 3 μm, from the viewpoints of colorability, color development, easy decolorization, stability, fluidity in ink, suppression of adverse effects on writing properties, compatibility with the photochromic microencapsulated pigment described below, etc. The "average particle size" specified here is the value obtained by measuring the average particle size (50% diameter) (refractive index 1.8) using a particle size analyzer [Microtrac HRA9320-X100 (manufactured by Nikkiso Co., Ltd.)].

[0058] If the average particle size is less than 0.2 μm, sufficient line density cannot be obtained, while if it exceeds 5 μm, it is undesirable because it deteriorates writing properties, reduces the dispersion stability of the thermochromic microencapsulated pigment, and tends to cause ink back due to vibration. Furthermore, the 90% diameter is 8 μm or less, preferably 6 μm or less. If a certain proportion or more of particles with large diameters are present, the above-mentioned effects tend to become more pronounced. Note that the microencapsulated pigment having the above-mentioned average particle size range (0.2 to 5 μm) varies depending on the microencapsulation method, but in a phase separation method from an aqueous solution, it can be prepared by appropriately combining the stirring conditions when producing the microencapsulated pigment.

[0059] The specific gravity of the thermochromic microencapsulated pigment is in the range of 0.9 to 1.3, preferably 1.0 to 1.2. If the specific gravity is outside this range, the dispersion stability of the microencapsulated pigment is likely to decrease. Furthermore, if the specific gravity exceeds 1.3, ink back is likely to occur due to vibration.

[0060] In the aqueous ink composition for writing instruments, in addition to the above-mentioned thermochromic microencapsulated pigment, the remainder is water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.) as a solvent, and in addition, depending on the application of each writing instrument (for ballpoint pen, marking pen, etc.), water-soluble organic solvents, thickeners, lubricants, rust inhibitors, preservatives, antibacterial agents, etc. may be appropriately contained within a range that does not impair the effects of the agent.

[0061] Examples of the water-soluble organic solvent that can be used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, 3-butylene glycol, thiodiethylene glycol, and glycerin, as well as ethylene glycol monomethyl ether and diethylene glycol monomethyl ether, which can be used alone or in combination.

[0062] Of these, it is preferable to use glycerin in order to prevent ink solidification at the writing part due to the ink bag, and the amount added is preferably 1 to 10 mass % of the total amount of ink. Although the mechanism of action of glycerin is unknown, it is presumed to have the effect of reducing the cohesive force between the pigment and ink components in a dry state.

[0063] The usable thickener is preferably at least one selected from the group consisting of synthetic polymers, cellulose, and polysaccharides.Specific examples of the thickener include gum arabic, tragacanth gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, welan gum, succinoglycan, diutan gum, dextran, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, starch glycolic acid and its salts, propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, polyacrylic acid and its salts, carboxyvinyl polymer, polyethylene oxide, copolymer of vinyl acetate and polyvinylpyrrolidone, crosslinked acrylic acid polymer and its salts, non-crosslinked acrylic acid polymer and its salts, styrene acrylic acid copolymer and its salts, etc.

[0064] Among these, it is preferable to use polysaccharides. Due to their rheological properties, polysaccharides tend to be less susceptible to the influence of vibration on the fluidity, and are less likely to cause problems such as poor writing caused by ink bag. Xanthan gum is particularly preferable because it has an excellent balance with other properties required for writing instrument inks.

[0065] Examples of lubricants include fatty acid esters of polyhydric alcohols, higher fatty acid esters of sugars, polyoxyalkylene higher fatty acid esters, alkyl phosphate esters, alkyl sulfonates of higher fatty acid amides, alkyl aryl sulfonates, derivatives of polyalkylene glycols, fluorine-based surfactants, polyether-modified silicones, etc., which are also used as surface treatment agents for pigments. Examples of rust inhibitors include benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, saponins, etc. Examples of preservatives or antibacterial agents include phenol, sodium omadine, sodium benzoate, and benzimidazole-based compounds.

[0066] To produce this aqueous ink composition for writing instruments, a conventionally known method can be adopted, and for example, the composition can be obtained by blending the thermochromic and photochromic microencapsulated pigments and the other aqueous components in predetermined amounts, and stirring and mixing them with a stirrer such as a homomixer or a disperser. If necessary, coarse particles in the ink composition may be removed by filtration or centrifugation.

[0067] The viscosity value of the aqueous ink composition for writing instruments is preferably 500 to 2000 mPa·s at 25°C and a shear rate of 3.83 / s, and 20 to 100 mPa·s at a shear rate of 383 / s. By setting the viscosity within the above range, an ink having excellent writing properties and stability over time can be obtained. Furthermore, when S=αD n (where 1>n>0) (S is the shear stress (dyn / cm 2 ), D is the shear rate (s -1 It is preferable that the non-Newtonian viscosity index n, calculated by the viscosity equation expressed by (α is the non-Newtonian viscosity coefficient), is 0.2 to 0.6. By setting the non-Newtonian viscosity index n within the above range in addition to the above viscosity range, it becomes possible to appropriately set the fluidity of the ink against vibration, and it becomes possible to prevent the occurrence of ink back.

[0068] The surface tension of the aqueous ink composition for writing instruments is preferably 25 to 45 mN / m, more preferably 30 to 40 mN / m. Within this range, the balance between the wettability of the inside of the pen tip and the ink becomes appropriate, making it possible to prevent the occurrence of ink back.

[0069] In the refill, an ink follower may be disposed immediately behind the ink. The material constituting the follower may be composed of at least a non-volatile or low-volatility organic solvent and a thickener. The non-volatile or low-volatility organic solvent used in the ink follower is used as the base oil of the ink follower, and liquid paraffin is used, for example. Mineral oil and chemically synthesized oil are used for the liquid paraffin, and polybutene, polyα-olefin, ethylene α-olefin oligomer, etc. can be used as the chemically synthesized oil.

[0070] Specific examples of mineral oils that can be used include commercially available Diana Process Oil NS-100, PW-32, PW-90, NR-68, and AH-58 (manufactured by Idemitsu Kosan Co., Ltd.).

[0071] Specific examples of polybutenes that can be used include commercially available products such as Nissan Polybutene 200N, Polybutene 30N, Polybutene 10N, Polybutene 5N, Polybutene 3N, Polybutene 015N, Polybutene 06N, and Polybutene 0N (all manufactured by NOF Corporation), Polybutene HV-15 (manufactured by Nippon Petrochemical Industry Co., Ltd.), and 35R (manufactured by Idemitsu Kosan Co., Ltd.).

[0072] Specific examples of poly-α-olefins that can be used include commercially available barrel process oils P-26, P-46, P-56, P-150, P-350, P-1500, P-2200, (P-10000, P-37500) (manufactured by Matsumura Oil Co., Ltd.), and the like.

[0073] Specific examples of ethylene α-olefin oligomers that can be used include commercially available products such as LUCANT HC-10, HC-20, HC-100, HC-150, (HC-600, HC-2000) (all manufactured by Mitsui Chemicals, Inc.).

[0074] These non-volatile or slightly volatile organic solvents can be used alone or in combination of two or more.

[0075] Examples of thickeners used in the ink follower include calcium salts of phosphate esters, fine silica particles, polystyrene-polyethylene / butylene rubber-polystyrene block copolymers, polystyrene-polyethylene / propylene rubber-polystyrene block copolymers, hydrogenated styrene-butadiene rubber, styrene-ethylenebutylene-olefin crystal block copolymers, olefin crystal-ethylenebutylene-olefin crystal block copolymers, and acetoalkoxyaluminum dialkylates, and these may be used alone or in combination of two or more.

[0076] A preferred commercially available product of calcium salt of phosphoric acid ester that can be used is Crodax DP-301LA (manufactured by Croda Japan Co., Ltd.) etc. The particulate silica that can be used includes hydrophilic particulate silica and hydrophobic particulate silica, and preferred commercially available products of hydrophilic silica include AEROSIL-300 and AEROSIL-380 (manufactured by Nippon Aerosil Co., Ltd.) etc., and preferred commercially available products of hydrophobic silica include AEROSIL-974D and AEROSIL-972 (manufactured by Nippon Aerosil Co., Ltd.) etc.

[0077] In addition, preferred commercially available polystyrene-polyethylene / butylene rubber-polystyrene block copolymers include Kraton GFG-1901X, Kraton GG-1650 (both manufactured by Shell Japan), Septon 8007, Septon 8004 (both manufactured by Kuraray Co., Ltd.), etc. Furthermore, preferred commercially available polystyrene-polyethylene / propylene rubber-polystyrene block copolymers include Kraton GG-1730 (manufactured by Shell Japan), Septon 2006, Septon 2063 (both manufactured by Kuraray Co., Ltd.), etc.

[0078] Preferred commercially available hydrogenated styrene-butadiene rubbers include DYNARON 1320P, DYNARON 1321P (both manufactured by JSR Corporation), Tuftec H1041, and Tuftec H1141 (both manufactured by Asahi Chemical Industry Co., Ltd.).

[0079] Preferred commercially available styrene-ethylenebutylene-olefin crystalline block copolymers include DYNARON 4600P (manufactured by JSR Corporation), and preferred commercially available olefin crystalline-ethylenebutylene-olefin crystalline block copolymers include DYNARON 6200P and DYNARON 6201B (manufactured by JSR Corporation).

[0080] A preferred commercially available acetoalkoxyaluminum dialkylate is PLENACT AL-M (manufactured by Ajinomoto Fine-Techno Co., Ltd.).

[0081] Among these thickeners, in order to further exert the effects of the present invention, it is preferable to use thermoplastic olefin-based elastomers such as styrene-ethylenebutylene-olefin crystalline block copolymers and olefin crystalline-ethylenebutylene-olefin crystalline block copolymers.

[0082] Furthermore, in order to obtain an ink follower that prevents the occurrence of ink back, it is preferable that the average value of tan δ measured for each frequency while exponentially increasing in the frequency range of 1 to 63 rad / s is 1.0 or more, and more preferably 1.7 to 3.4.

[0083] Here, tan δ is a value that means the loss modulus / storage modulus, and it has been known in the past that the average value of tan δ measured for each frequency while exponentially increasing in the frequency range of "1 to 63 rad / s" is preferably 1.0 or less. In the present invention, by making the average value of tan δ measured for each frequency in the above 1 to 63 rad / s 1.0 or more, it becomes possible to absorb vibration and prevent the occurrence of ink back.

[0084] The material for forming the friction body may be a rubber elastic material such as thermosetting rubber, such as silicone rubber, nitrile rubber, ethylene propylene rubber, ethylene propylene diene rubber, etc.; a thermoplastic elastomer, such as a styrene-based elastomer, an olefin-based elastomer, a polyester-based elastomer, a urethane-based elastomer, etc.; a mixture of two or more rubber elastic materials; or a mixture of a rubber elastic material and a synthetic resin. The friction body is formed by configuring this so that the Taber abrasion amount is less than 25 mg when using the abrasion wheel CS-17 of the Taber abrasion tester under a load of 9.8 N and 1000 rpm in the abrasion test (ASTM D1044) specified in JIS K7204.

[0085] Moreover, alkylsulfonic acid phenyl ester and cyclohexanedicarboxylic acid ester may be added to the material of the friction body. By including alkylsulfonic acid phenyl ester and cyclohexanedicarboxylic acid ester in the friction body, it becomes possible to erase handwriting without damaging the paper surface and without blurring the printed characters. Furthermore, it is preferable that the friction body has a durometer D hardness of 30 or more as specified in JIS K6203. This ensures a predetermined hardness and enables a more stable rubbing operation. The friction body can also be used as a touch pen or a stylus pen, and may be made conductive.

[0086] In addition, the friction body is preferably colored with a color having a lower brightness value than the color of the thermochromic ink contained in the refill. In other words, when the thermochromic ink of the multi-core writing instrument 1 is transferred to the surface of the friction body without discoloration during use of the friction body, the transfer of the thermochromic ink can be made inconspicuous. In particular, by making the color of the friction body black or having a brightness value of 2.5 or less, it is possible to make the stains on the surface of the friction body that occur during use less noticeable.

[0087] The lightness value is determined by using the Munsell color system with a measuring device such as a general-purpose color difference meter (TC-8600A, manufactured by Tokyo Denshoku Co., Ltd.), the lightness value of the friction body is measured on the surface, and the lightness value of the thermochromic ink is determined by measuring the ink on a line drawn on paper (old JIS P3201; high-quality paper made from 100% chemical pulp, basis weight range 40 to 157 g / m2, whiteness 75.0% or more) at a writing speed of 4.5 m / min with a pitch interval of 0.1 mm. [Explanation of symbols]

[0088] 1 Multi-core writing instrument 2 shaft cylinder 3 Front axle 4 Center axis 5 Refills 6 Spring 10 rear axle 20 Operation member 21 Operation protrusion 23 Cam groove 30 Rotating member 34 Cam protrusion 40 Slide Cam 50 Knock parts 60 Rotor 70 Slider

Claims

[Claim 1] The invention described herein.

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