Knock-type writing instrument

Abstract

To provide a knock type writing instrument having a knock mechanism which can meet various demands about its design or layout.SOLUTION: A knock type writing instrument 1 includes an operation part 30 and a cover member 50 which covers a rear end part of the operation part 30. A fitting hole 35 is provided on a rear end surface of the operation part 30, and a fitting part 51 protruding forward is provided on an inner rear end surface of the cover member 50. The fitting part 51 is inserted into the fitting hole 35 to fit therewith and thereby causes the cover member 50 to fit in the operation part 30.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a knock-type writing instrument. [Background technology]

[0002] A so-called knock-type knock-type writing instrument is known which has an operating part at the rear end of the barrel, and which switches between a writing state in which the writing part (the tip of the pen) protrudes from the tip of the barrel and a non-writing state in which the writing part is retracted into the barrel by performing a knock operation that presses the operating part forward against the biasing force of a spring located inside the barrel (for example, Patent Document 1).

[0003] The operation of switching between the writing state and the non-writing state by the knock mechanism in a typical knock type writing instrument as shown in Patent Document 1 will be described with reference to the schematic diagrams shown in Figs. 14 and 15. Fig. 14 is a schematic diagram of a knock mechanism 100 having a barrel 130, an operating unit 140, and a rotor 150, which is developed in the circumferential direction. Fig. 15 is a schematic diagram showing the positional relationship between the barrel 130, the operating unit 140, and the rotor 150, and shows the positions of the locking protrusion 141 of the operating unit 140 and the inner cam 156 of the rotor 150 relative to the outer cam 131 developed in the circumferential direction. In the diagram, the lower side is the front of the knock type writing instrument, above It is better to use a knock-type writing instrument. rear The rotor 150 rotates around the central axis with each knock operation, and therefore moves from right to left in the figure.

[0004] The knock mechanism 100 of the knock-type writing instrument has a barrel 130, an operating part 140, and a rotor 150 arranged in front of the operating part 140. Four outer cams 131 are provided at equal intervals in the circumferential direction at the rear end of the inner peripheral surface of the barrel 130. Four first guide grooves 132 extending in the front-rear direction are defined by adjacent outer cams 131. Each of the outer cams 131 is composed of a first protrusion 133, a second protrusion 134, and a third protrusion 135 that extend in the front-rear direction and are arranged continuously in the circumferential direction. The third protrusion 135 arranged in the middle has a radial thickness thinner than the first protrusion 133 and the second protrusion 134. Therefore, a second guide groove extending in the front-rear direction is formed between the first protrusion 133 and the second protrusion 134. In addition, the widths of the first protrusion 133, the second protrusion 134, the third protrusion 135, and the first guide groove 132 in the circumferential direction are formed to be equal. Therefore, the widths of the first guide groove 132 and the second guide groove are equal.

[0005] Eight locking protrusions 141 are provided at equal intervals in the circumferential direction on the outer peripheral surface on the front side of the operating part 140. Each of the locking protrusions 141 is disposed in the first guide groove 132 between adjacent outer cams 131, or on the third protrusion 135, i.e., in the second guide groove between the first protrusion 133 and the second protrusion 134. Each of the locking protrusions 141 is configured to move in the front-rear direction within the first guide groove 132 or the second guide groove by a knock operation. A cam surface 142 is formed on the front end surface of the operating part 140.

[0006] A cam receiving surface 153 that cooperates with and has a complementary shape to the cam surface 142 of the operating portion 140 is formed on the rear end surface of the rotor 150. Four inner cams 156 consisting of protrusions extending in the front-rear direction are provided at equal intervals in the circumferential direction on the outer peripheral surface of the rotor 150. When the rotor 150 rotates around the central axis by a knock operation, the inner cams 156 engage with the outer cams 131 or are disposed in the first guide grooves 132 between the outer cams 131. When the inner cams 156 are disposed in the first guide grooves 132 between the outer cams 131, the outer cams 131 are disposed between the inner cams 156.

[0007] The knock operation is performed by pressing the operating part 140 forward and moving it forward to a predetermined position. As the operating part 140 moves due to the knock operation, the rotor 150 is pressed and moves forward inside the barrel 130. In the non-writing state (FIG. 15(a)), when the operating part 140 is moved forward until the inner cam 156 of the rotor 150 passes the first protrusion 133 of the outer cam 131 of the barrel 130 (FIG. 15(b)), the cam surface 142 and the cam receiving surface 153, which are arranged out of phase with each other, cooperate with each other, and the rotor 150 rotates until the cam surface 142 and the cam receiving surface 153 coincide with each other (FIG. 15(c)). Next, when the force applied to the operating portion 140 is released, the rear end surface of the inner cam 156 and the front end surface of the outer cam 131 cooperate to rotate the rotor 150 until the inner cam 156 engages with the second protrusion 134 of the outer cam 131 (Figure 15 (d)), thereby entering the writing state.

[0008] On the other hand, in the writing state (FIG. 15(d)), when the operating part 140 is moved forward until the inner cam 156 of the rotor 150 passes the second protrusion 134 of the outer cam 131 of the barrel 130 (FIG. 15(b)), the cam surface 142 and the cam receiving surface 153 arranged out of phase with each other cooperate, and the rotor 150 rotates until the cam surface 142 and the cam receiving surface 153 coincide with each other (FIG. 15(c)). Next, when the force applied to the operating part 140 is released, the rear end surface of the inner cam 156 and the front end surface of the outer cam 131 cooperate to rotate the rotor 150 until the inner cam 156 enters the first guide groove 132 (FIG. 15(a)), and the non-writing state is entered. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2015-003443 A Summary of the Invention [Problem to be solved by the invention]

[0010] The knock-type writing instrument described in Patent Document 1 has a knock mechanism that includes an operating part and a cover member that covers the rear end of the operating part. The operating part and the cover member are integrally connected by fitting the outer peripheral surface of the operating part and the inner peripheral surface of the cover member.

[0011] Due to design or aesthetic requirements, the operating part is formed into various shapes other than the shape of the operating part described in Patent Document 1. For this reason, depending on the shape of the operating part, it may not be possible to apply the fitting structure between the outer peripheral surface of the operating part and the inner peripheral surface of the cover member as shown in Patent Document 1. For this reason, the more variations there are in the fitting structure between the operating part and the cover member in the knock mechanism, the more design or aesthetic requirements can be met.

[0012] An object of the present invention is to provide a knock-type writing instrument having a knock mechanism that can meet various requirements in terms of aesthetics or design. [Means for solving the problem]

[0013] According to one aspect of the present invention, there is provided a knock-type writing instrument comprising an operating portion and a cover member covering a rear end portion of the operating portion, wherein an engagement hole is provided on the rear end surface of the operating portion, and an engagement portion protruding forward is provided on the inner rear end surface of the cover member, and the engagement portion is inserted into and engages with the engagement hole, thereby engaging the cover member with the operating portion.

[0014] A first locking portion may be provided on the inner surface of the fitting hole, and a second locking portion may be provided on the outer surface of the fitting portion, and the first locking portion and the second locking portion may be capable of locking with each other. The cover member may be formed transparent or translucent. A restricting protrusion may be provided on the inner surface of the cover member, and the rear end of the operating portion may be engaged with the restricting protrusion to restrict the entry of the operating portion into the cover member. The operating portion may have an erasing portion capable of erasing handwriting of the knock type writing instrument. The knock type writing instrument may be a knock type writing instrument having thermochromic ink, and the handwriting of the thermochromic ink may be thermochromic due to frictional heat generated when rubbed by the erasing portion. Effect of the Invention

[0015] According to the aspects of the present invention, a common effect is achieved in that a knock type writing instrument having a knock mechanism that can meet various requirements in terms of design or engineering is provided. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a vertical cross-sectional view of a knock-type writing instrument according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the rear end portion of the knock-type writing instrument of FIG. [Diagram 3] FIG. 3 is a perspective view of the rear end portion of the knock-type writing instrument of FIG. [Figure 4] 4 is a vertical cross-sectional view of the rear end portion of the barrel of the knock-type writing instrument of FIG. [Diagram 5] 5 is a perspective view of an operation unit and a rotor of the knock-type writing instrument of FIG. [Figure 6] FIG. 6 is a schematic diagram of the knock mechanism showing the switching from the non-writing state to the writing state of the knock type writing instrument of FIG. [Figure 7] FIG. 7 is a schematic diagram of the knock mechanism showing the switching from the writing state to the non-writing state of the knock type writing instrument of FIG. [Figure 8] FIG. 8 is a vertical cross-sectional view of a knock-type writing instrument according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a vertical cross-sectional view of the rear end portion of the knock-type writing instrument of FIG. [Figure 10] 10 is a vertical cross-sectional view of the rear end portion of the barrel of the knock-type writing instrument of FIG. [Figure 11] 11 is a perspective view of the operating portion and the rotor of the knock-type writing instrument of FIG. [Figure 12] FIG. 12 is a schematic diagram of the knock mechanism showing the switching from the non-writing state to the writing state of the knock type writing instrument of FIG. [Figure 13] FIG. 13 is a schematic diagram of the knock mechanism showing the switching from the writing state to the non-writing state of the knock type writing instrument of FIG. [Figure 14] FIG. 14 is a schematic diagram of a knock mechanism of a conventional knock-type writing instrument. [Figure 15] FIG. 15 is a schematic diagram of a knock mechanism showing switching from a non-writing state to a writing state of a conventional knock-type writing instrument. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] 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.

[0018] FIG. 1 is a longitudinal cross-sectional view of a knock-type writing instrument 1 according to a first embodiment of the present invention, FIG. 2 is a longitudinal cross-sectional view of the rear end portion of the knock-type writing instrument 1 of FIG. 1, and FIG. 3 is a perspective view of the rear end portion of the knock-type writing instrument 1 of FIG. 1.

[0019] The knock-type writing instrument 1 has a barrel 3 formed in a cylindrical shape and equipped with a tip member 2, a refill 5 which is a writing body arranged inside the barrel 3 and equipped with a writing part 4 at one end, a spring 6 which biases the refill 5 rearward, and a knock mechanism 10 arranged at the rear end of the barrel 3. The knock mechanism 10 has an outer cam 20, an operating part 30, a rotor 40, and a cover member 50. The tip member 2 arranged at the front end of the barrel 3 is formed in a tapered shape toward the front, and has a through hole for allowing the writing part 4 of the refill 5 to protrude.

[0020] In this specification, in the axial direction of the knock type writing instrument 1, the side of the writing part 4 is defined as the "front" side, and the side opposite the writing part 4 is defined as the "rear" side. In addition, in the knock type writing instrument 1, the knock mechanism 10 moves the refill 5 in the front-rear direction within the barrel 3. At this time, the state in which the writing part 4 is retracted into the barrel 3 is referred to as the non-writing state (FIG. 1), and the state in which the writing part 4 protrudes from the barrel 3 is referred to as the writing state (not shown).

[0021] FIG. 4 is a vertical cross-sectional view of the rear end of the barrel 3 of the knock-type writing instrument 1 of FIG. 1. In FIG. 4, the lower side is the front of the knock-type writing instrument 1. Four outer cams 20 constituting a part of the knock mechanism 10 are provided at equal intervals in the circumferential direction on the inner surface of the rear end of the barrel 3. Four first guide grooves 21 extending in the front-rear direction are defined by adjacent outer cams 20. Each of the outer cams 20 is composed of a first protrusion 22 and a second protrusion 23 extending in the front-rear direction and arranged continuously in the circumferential direction. The first protrusion 22 and the second protrusion 23 have the same shape. A second guide groove 24 extending in the front-rear direction is formed between the first protrusion 22 and the second protrusion 23. The width of the first guide groove 21 in the circumferential direction is larger than the width of the second guide groove 24 in the circumferential direction. The depth of the first guide groove 21 and the depth of the second guide groove 24 are the same. In the outer cam 20, a regulating surface 25 is provided at the rear ends of the first guide groove 21 and the second guide groove 24. In addition, the surface of the outer cam 20 opposite to the regulating surface 25, i.e., the rear end surface of the outer cam 20, forms an abutment surface 26 with which the front end surface of the cover member 50 can abut.

[0022] Fig. 5 is a perspective view of the operation unit 30 (so-called knock bar) and rotor 40 of the knock type writing instrument 1 of Fig. 1. In Fig. 5, the lower side is the front of the knock type writing instrument 1.

[0023] The operating part 30 is a cylindrical member formed in a gentle taper toward the rear. Eight locking protrusions 31 are provided at equal intervals in the circumferential direction on the outer peripheral surface of the front side of the operating part 30. Each of the locking protrusions 31 is disposed in the first guide groove 21 between the adjacent outer cams 20, or on the second protrusion 23, i.e., in the second guide groove 24 between the first protrusion 22 and the second protrusion 23. Each of the locking protrusions 31 is configured to move in the front-rear direction in the first guide groove 21 or the second guide groove 24 by a knock operation.

[0024] A cam surface 32 is formed on the front end surface of the operating part 30. The cam surface 32 has eight peaks 33 and valleys 34. A circular fitting hole 35 into which a fitting portion 51 of a cover member 50 described later is inserted is provided at the rear end of the operating part 30. A first locking portion 36 that protrudes radially inward is provided on the inner surface near the opening of the fitting hole 35 (FIG. 2).

[0025] The rotor 40 is composed of a small diameter portion 41 that is inserted into the front end of the operating part 30 and used for centering, and a large diameter portion 42 that is disposed in front of the small diameter portion 41. The large diameter portion 42 has a diameter larger than that of the small diameter portion 41. A cam receiving surface 43 that cooperates with and has a complementary shape to the cam surface 32 of the operating part 30 is formed on the rear end surface of the large diameter portion 42. The cam receiving surface 43 has eight peaks 44 and valleys 45, similar to the cam surface 32 of the operating part 30. Four inner cams 46, which are protrusions extending in the front-rear direction, are provided at equal intervals in the circumferential direction on the outer circumferential surface of the large diameter portion 42. As shown in FIG. 2, the rear end of the refill 5 is inserted into the front end opening of the rotor 40. This allows the overall length of the knock-type writing instrument 1 to be shortened.

[0026] FIG. 6 is a schematic diagram of the knock mechanism 10 showing the switching from the non-writing state to the writing state of the knock type writing instrument 1 of FIG. 1. That is, FIG. 6 is a schematic diagram showing the positional relationship between the outer cam 20, the operating part 30, and the rotor 40, and shows the positions of the locking protrusion 31 of the operating part 30 and the inner cam 46 of the rotor 40 with respect to the outer cam 20 developed in the circumferential direction. In the figure, the lower side is the front of the knock type writing instrument 1, and the upper side is the rear of the knock type writing instrument 1. The rotor 40 is given a rotational force by the cooperation of the cam surface 32 of the operating part 30 and the cam receiving surface 43 of the rotor 40, and rotates around the central axis. Therefore, the rotor 40 moves from right to left in FIG. 6 with each knock operation.

[0027] 6(a) is a schematic diagram of the knock mechanism 10 in the non-writing state of the knock-type writing instrument 1. At this time, the inner cam 46 of the rotor 40, which is urged backward by the spring 6 via the refill 5, is disposed in the first guide groove 21 between the outer cams 20. Therefore, in this state, the writing part 4 is sunk in the barrel 3. Also, the locking protrusion 31 of the operating part 30 is disposed in the first guide groove 21 or the second guide groove 24. The cam surface 32 and the cam receiving surface 43 are disposed out of phase with each other.

[0028] 6(a), a knock operation is performed to press the operating part 30 against the biasing force of the spring 6, thereby moving the operating part 30 and the rotor 40 forward. At this time, the locking protrusion 31 of the operating part 30 and the inner cam 46 of the rotor 40 move forward in the first guide groove 21. In addition, the operating part 30 and the rotor 40 receive circumferential force components in opposite directions via the inclined surfaces of the cam surface 32 and the cam receiving surface 43, but the circumferential movement is restricted by the abutment of the locking protrusion 31 with the side surfaces of the first protrusion 22 and the second protrusion 23 of the outer cam 20.

[0029] When the operating part 30 and the rotor 40 move further forward, the rear end of the inner cam 46 passes over the front end of the outer cam 20 in the front-rear direction, i.e., the first protrusion 22 (FIG. 6(b)). At this time, the restriction of the circumferential movement of the rotor 40 by the outer cam 20 is released, and the cam surface 32 and the cam receiving surface 43 coincide with each other.

[0030] When the pressure of the operating part 30 is released from the state where the cam surface 32 and the cam receiving surface 43 are aligned, the operating part 30 and the rotor 40 move backward by the biasing force of the spring 6. At this time, the rotor 40 receives a component force from the inclined surface of the outer cam 20 and rotates around the central axis. That is, the inner cam 46 of the rotor 40 moves along the inclined surface of the outer cam 20 until it abuts against the front end side surface of the second protrusion 23, and the rotation of the rotor 40 stops. As described above, the width of the inner cam 46 in the circumferential direction is smaller than the width of the first guide groove 21 and larger than the width of the second guide groove 24, so that the inner cam 46 cannot enter the second guide groove 24. Therefore, the inner cam 46 engages with the front end surface of the first protrusion 22, and the backward movement of the rotor 40 is restricted (FIG. 6(c)). As a result, the writing part 4 of the refill 5 arranged in front of the rotor 40 protrudes from the barrel 3, and the knock-type writing instrument 1 enters a writing state.

[0031] Fig. 7 is a schematic diagram of the knock mechanism 10 showing the switching from the writing state to the non-writing state of the knock-type writing instrument 1 in Fig. 1. Fig. 7 shows the positional relationship between the outer cam 20, the operating part 30, and the rotor 40 in the same manner as Fig. 6.

[0032] FIG. 7(a) is a schematic diagram of the knock mechanism 10 in the writing state of the knock-type writing instrument 1, and is the same schematic diagram as FIG. 6(c). From the state of FIG. 7(a), a knock operation is performed to press the operating part 30 against the biasing force of the spring 6, thereby moving the operating part 30 and the rotor 40 forward. At this time, the locking protrusion 31 of the operating part 30 and the inner cam 46 of the rotor 40 move forward in the first guide groove 21. In addition, the operating part 30 and the rotor 40 receive circumferential force components in opposite directions via the inclined surfaces of the cam surface 32 and the cam receiving surface 43, but the circumferential movement is restricted by the abutment of the locking protrusion 31 with the side surfaces of the first protrusion 22 and the second protrusion 23 of the outer cam 20.

[0033] When the operating part 30 and the rotor 40 move further forward, the rear end of the inner cam 46 passes over the front end of the outer cam 20 in the front-rear direction, i.e., the second protrusion 23 (FIG. 7(b)). At this time, the restriction of the circumferential movement of the rotor 40 by the outer cam 20 is released, and the cam surface 32 and the cam receiving surface 43 coincide with each other.

[0034] When the pressure on the operating part 30 is released from the state where the cam surface 32 and the cam receiving surface 43 are aligned, the operating part 30 and the rotor 40 move backward due to the biasing force of the spring 6. At this time, the rotor 40 receives a component force from the inclined surface of the outer cam 20 and rotates around the central axis. That is, the inner cam 46 of the rotor 40 enters the first guide groove 21 from the inclined surface of the outer cam 20 and moves backward, so that the operating part 30 and the rotor 40 move backward. The backward movement of the operating part 30 and the rotor 40 is restricted by the engagement of the locking protrusion 31 of the operating part 30 with the restriction surface 25 provided at the rear end of the first guide groove 21 and the second guide groove 24 (FIG. 7(c)). As a result, the writing part 4 of the refill 5 arranged in front of the rotor 40 is retracted into the barrel 3, and the knock-type writing instrument 1 is in a non-writing state.

[0035] As described above with reference to Fig. 15, in the outer cam 131 of the conventional knock mechanism 100 as described in Patent Document 1, the third protrusion 135 disposed in the middle is a second guide groove in which the locking protrusion 141 of the operation part 140 is disposed. At the same time, as shown in Fig. 15(d), the third protrusion 135 functions as a locking part that locks with the inner cam 156 so that the rotor 150 does not move backward in the writing state. Therefore, the outer cam 131 needs to have a certain thickness in two stages so that it also functions as a locking part.

[0036] On the other hand, the knock mechanism 10 of the above-mentioned knock type writing instrument 1 does not have a configuration equivalent to the third protrusion 135 in the conventional knock mechanism 100, but instead prevents the inner cam 46 from entering by narrowing the width of the second guide groove 24, and the first protrusion 22 functions as a locking part that locks with the inner cam 46 so that the rotor 40 does not move backward in the writing state. Therefore, the outer cam 20 as a whole only needs to have one thickness stage, that is, the first protrusion 22 and the second protrusion 23.

[0037] As a result, the outer cam 20 can be made thinner than the outer cam 131 in the conventional knock mechanism 100, and when considering a barrel with the same inner diameter, the inner diameter of the outer cam 20 portion can be made larger. Therefore, the outer diameter of the operating part 30 that moves in the front-rear direction inside the radial direction of the outer cam 20 in the barrel 3 of the knock type writing instrument 1 can be made larger, and various requirements in terms of design and aesthetics can be met.

[0038] The cover member 50 will be described with reference to FIG. 2. The cover member 50 has an inner rear end surface provided with a fitting portion 51 that protrudes forward. When the cover member 50 is fitted to the operating unit 30, the fitting portion 51 is inserted into the fitting hole 35 of the operating unit 30. The fitting portion 51 is, for example, cylindrical, and a second locking portion 52 that protrudes outward with respect to the central axis is provided on the outer surface of the front end of the fitting portion 51. The front end of the fitting portion 51 can be bent radially inward by, for example, providing a plurality of slits extending rearward from the front end. When the fitting portion 51 of the cover member 50 is inserted into the fitting hole 35 of the operating unit 30, the second locking portion 52 of the fitting portion 51 of the cover member 50 rides over the first locking portion 36 of the fitting hole 35 of the operating unit 30, so that the operating unit 30 and the cover member 50 are fitted together in a snap manner. The first locking portion 36 and the second locking portion 52 can be locked to each other when the cover member 50 is fitted to the operating portion 30. In other words, as long as the first locking portion 36 and the second locking portion 52 can be locked to each other, the first locking portion 36 and the second locking portion 52 can be configured in any manner.

[0039] A restricting portion 53 is provided on the inner surface of the rear end portion of the cover member 50. When the operating portion 30 and the cover member 50 are fitted together, the rear end portion of the operating portion 30 engages with the restricting portion 53, thereby restricting the operation portion 30 from entering the cover member 50. A ring-shaped or arc-shaped ventilation hole 54 is provided at the rear end portion of the cover member 50. The provision of the ventilation hole 54 makes it possible to ensure safety without blocking the airway even if an infant or the like accidentally swallows the cover member 50.

[0040] In a state where the operating unit 30 and the cover member 50 are fitted together, the inner surface of the cover member 50 is in close contact with or close to the outer surface of the operating unit 30 as a whole. In other words, the operating unit 30 and the cover member 50 are formed so that the inner surface of the cover member 50 is in close contact with or close to the outer surface of the operating unit 30 as a whole. Therefore, the operating unit 30 can be formed thicker. Since the fitting portion 51 of the cover member 50 is inserted into the fitting hole 35 of the operating unit 30, the rear end portion of the operating unit 30 is in a state of being sandwiched between the inner surface of the cover member 50 and the fitting portion 51, and a stronger fit can be achieved.

[0041] Also, in order to fit the operating unit 30 into the fitting portion 51 provided on the inner rear end surface of the cover member 50, it is necessary to insert the operating unit 30 deep into the cover member 50. For this reason, for example, by making the cover member 50 transparent or semi-transparent or by providing a window or slit on the side of the cover member 50, the operating unit 30 arranged inside the cover member 50 can be made visible over substantially the entire length of the cover member 50. As a result, for example, by making the writing color of the refill 5 the same as the color of the operating unit 30, the user can easily recognize the writing color. Also, when the product is displayed in a store or when the product is purchased in a store, the writing color can be easily recognized and specified.

[0042] According to the above-described operating unit 30 and cover member 50, it is possible to increase the variety of fitting structures, and to provide a knock-type writing instrument 1 having a knock mechanism that can meet various design or engineering requirements.

[0043] Fig. 8 is a vertical cross-sectional view of a knock type writing instrument 11 according to a second embodiment of the present invention, and Fig. 9 is a vertical cross-sectional view of the rear end portion of the knock type writing instrument 11 of Fig. 8. The knock type writing instrument 1 according to the first embodiment and the knock type writing instrument 11 according to the second embodiment are significantly different in the shape and configuration of the knock mechanism.

[0044] The knock-type writing instrument 11 has a barrel 3 formed in a cylindrical shape and equipped with a tip member 2, a refill 5 which is a writing body arranged inside the barrel 3 and equipped with a writing part 4 at one end, a spring 6 which urges the refill 5 rearward, and a knock mechanism 60 arranged at the rear end of the barrel 3. The knock mechanism 60 has an outer cam 70, an operating part 80, a rotor 90, and a cover member 50. The tip member 2 arranged at the front end of the barrel 3 is formed in a tapered shape toward the front, and has a through hole for allowing the writing part 4 of the refill 5 to protrude.

[0045] FIG. 10 is a vertical cross-sectional view of the rear end of the barrel 3 of the knock-type writing instrument 11 of FIG. 8. In FIG. 10, the lower side is the front of the knock-type writing instrument 11. Four outer cams 70 constituting a part of the knock mechanism 60 are provided at equal intervals in the circumferential direction on the inner surface of the rear end of the barrel 3. Four first guide grooves 71 extending in the front-rear direction are defined by adjacent outer cams 70. Each of the outer cams 70 is composed of a first protrusion 72, a second protrusion 73, and a third protrusion 74 that extend in the front-rear direction and are arranged continuously in the circumferential direction. The third protrusion 74 arranged in the middle has a thinner radial thickness than the first protrusion 72 and the second protrusion 73. Therefore, a second guide groove 75 extending in the front-rear direction is formed between the first protrusion 72 and the second protrusion 73. In addition, the widths of the first protrusion 72, the second protrusion 73, the third protrusion 74, and the first guide groove 71 in the circumferential direction are formed to be equal. Therefore, the widths of the first guide groove 71 and the second guide groove 75 are equal.

[0046] A wedge-shaped locked portion 76 protruding into the second guide groove 75 is provided on a circumferential side surface of the first protrusion 72, particularly on the side surface near the rear end. Similarly, a protruding locked portion 76 protruding into the first guide groove 71 is provided on a circumferential side surface of the second protrusion 73, particularly on the side surface near the rear end. The locked portion 76 may protrude into the first guide groove 71 from the opposite circumferential side surface of the first protrusion 72, and may protrude into the second guide groove 75 from the opposite circumferential side surface of the second protrusion 73. In other words, the locked portion 76 is a convex portion protruding in the same circumferential direction from the side surfaces of the first protrusion 72 and the second protrusion 73.

[0047] The locked portion 76 has the same radial thickness as the first protrusion 72 and the second protrusion 73. The rear end surface of the locked portion 76 is flush with the rear end surfaces of the first protrusion 72 and the second protrusion 73, which are planes perpendicular to the central axis of the barrel 3. Since the locked portion 76 is wedge-shaped, the locked portion 76 facing the first guide groove 71 and the second guide groove 75 has a locked inclined surface 77 inclined in the circumferential direction with respect to the plane perpendicular to the central axis of the barrel 3. As described later, the locked inclined surface 77 of the locked portion 76 has the same function as the regulating surface 25 in the knock-type writing instrument 1 according to the first embodiment in that it engages with the locking protrusion 81 of the operating part 80. The rear end surface of the outer cam 70 constitutes an abutting surface 78 with which the front end surface of the cover member 50 can abut.

[0048] Fig. 11 is a perspective view of the operation unit 80 and the rotor 90 of the knock type writing instrument 11 of Fig. 8. In Fig. 11, the bottom is the front of the knock type writing instrument 11.

[0049] The operating part 80 is a cylindrical member formed in a gentle taper toward the rear. Eight locking protrusions 81 are provided at equal intervals in the circumferential direction on the outer peripheral surface of the front end of the operating part 80. Each locking protrusion 81 has a long and slender protruding leg 87 extending in the axial direction and a head 88 provided at the front end of the leg 87. Each of the locking protrusions 81 is disposed in the first guide groove 71 between the adjacent outer cams 70, or on the second protrusion 73, i.e., in the second guide groove 75 between the first protrusion 72 and the second protrusion 73. Each of the locking protrusions 81 is configured to move in the front-rear direction in the first guide groove 71 or the second guide groove 75 by a knock operation.

[0050] A cam surface 82 is formed on the front end surface of the operating portion 80. In detail, the front end surface of the locking projection 81, i.e., the front end surface of the head 88, constitutes part of the cam surface 82. The cam surface 82 has eight peaks 83 and valleys 84. A circular fitting hole 85 into which the fitting portion 51 of the cover member 50 is inserted is provided on the rear end of the operating portion 80. A first locking portion 86 that protrudes radially inward is provided on the inner surface near the opening of the fitting hole 85.

[0051] The rotor 90 consists of a small diameter section 91 that is inserted into the front end of the operating part 80 and used for centering, and a large diameter section 92 that is located in front of the small diameter section 91. The large diameter section 92 has a larger diameter than the small diameter section 91. A cam receiving surface 93 that cooperates with the cam surface 82 of the operating part 80 is formed on the rear end surface of the large diameter section 92. The cam receiving surface 93 has four peaks 94 and a valley 05. Four inner cams 96, which are protrusions that extend in the front-rear direction, are provided at equal intervals in the circumferential direction on the outer circumferential surface of the large diameter section 92.

[0052] The fitting structure between the operating portion 80 and the cover member 50 and the effects achieved thereby are the same as those described in the first embodiment, and therefore will not be described again.

[0053] FIG. 12 is a schematic diagram of the knock mechanism 60 showing the switching from the non-writing state to the writing state of the knock type writing instrument 11 of FIG. 8. That is, FIG. 12 is a schematic diagram showing the positional relationship between the outer cam 70, the operating part 80, and the rotor 90, and shows the positions of the locking protrusion 81 of the operating part 80 and the inner cam 96 of the rotor 90 with respect to the outer cam 70 developed in the circumferential direction. In the figure, the lower side is the front of the knock type writing instrument 11, and the upper side is the rear of the knock type writing instrument 11. The rotor 90 is given a rotational force by the cooperation of the cam surface 82 of the operating part 80 and the cam receiving surface 93 of the rotor 90, and rotates around the central axis. Therefore, the rotor 90 moves from right to left in FIG. 12 with each knock operation.

[0054] 12(a) is a schematic diagram of the knock mechanism 60 of the knock-type writing instrument 11 in a non-writing state. At this time, the inner cam 96 of the rotor 90, which is urged backward by the spring 6 via the refill 5, is disposed in the first guide groove 71 between the outer cams 70. Therefore, in this state, the writing part 4 is sunk in the barrel 3. The cam surface 82 and the cam receiving surface 93 are disposed out of phase with each other.

[0055] The locking protrusion 81 of the operating portion 80 is disposed in the first guide groove 71 or the second guide groove 75. In detail, the leg 87 of the locking protrusion 81 is always disposed between the locked portion 76 and the first protrusion 72 or between the locked portion 76 and the second protrusion 73 of the outer cam 70 during the knocking operation. In addition, the rear end of the leg 87 of the locking protrusion 81 always protrudes rearward beyond the outer cam 70 during the knocking operation.

[0056] 12(a), a knock operation is performed to press the operating part 80 against the biasing force of the spring 6, thereby moving the operating part 80 and the rotor 90 forward. At this time, the locking protrusion 81 of the operating part 80 and the inner cam 96 of the rotor 90 move forward in the first guide groove 71. In addition, the operating part 80 and the rotor 90 receive circumferential force components in opposite directions via the inclined surfaces of the cam surface 82 and the cam receiving surface 93, but the circumferential movement is restricted by the abutment of the locking protrusion 81 with the side surfaces of the first protrusion 72 and the second protrusion 73 of the outer cam 70.

[0057] When the operating part 80 and the rotor 90 move further forward, the rear end of the inner cam 96 passes over the front end of the outer cam 70 in the front-rear direction, i.e., the first protrusion 72 (FIG. 12(b)). At this time, the restriction of the circumferential movement of the rotor 90 by the outer cam 70 is released, and the cam surface 82 and the cam receiving surface 93 coincide with each other.

[0058] When the operating part 80 is released from the state where the cam surface 82 and the cam receiving surface 93 are aligned, the operating part 80 and the rotor 90 move backward due to the biasing force of the spring 6. At this time, the rotor 90 receives a component force from the inclined surface of the outer cam 70 and rotates around the central axis. That is, the inner cam 96 of the rotor 90 moves along the inclined surface of the outer cam 70 until it abuts against the front end side surface of the second protrusion 73, and the rotation of the rotor 90 stops. At this time, the inner cam 96 engages with the front end surface of the third protrusion 74, and the backward movement of the rotor 90 is restricted (FIG. 12(c)). As a result, the writing part 4 of the refill 5 arranged in front of the rotor 90 protrudes from the barrel 3, and the knock-type writing instrument 11 is in a writing state.

[0059] Fig. 13 is a schematic diagram of the knock mechanism 60 showing the switching from the writing state to the non-writing state of the knock type writing instrument 11 in Fig. 8. Fig. 13 shows the positional relationship between the outer cam 70, the operating part 80, and the rotor 90 in the same manner as Fig. 12.

[0060] FIG. 13(a) is a schematic diagram of the knock mechanism 60 in the writing state of the knock-type writing instrument 11, and is the same schematic diagram as FIG. 12(c). From the state of FIG. 13(a), a knock operation is performed to press the operating part 80 against the biasing force of the spring 6, thereby moving the operating part 80 and the rotor 90 forward. At this time, the locking protrusion 81 of the operating part 80 and the inner cam 96 of the rotor 90 move forward in the first guide groove 71. In addition, the operating part 80 and the rotor 90 receive circumferential force components in opposite directions via the inclined surfaces of the cam surface 82 and the cam receiving surface 93, but the circumferential movement is restricted by the side surfaces of the first protrusion 72 and the second protrusion 73 of the outer cam 70.

[0061] When the operating part 80 and the rotor 90 move further forward, the rear end of the inner cam 96 passes over the front end of the outer cam 70 in the front-rear direction, i.e., the second protrusion 73 (FIG. 13(b)). At this time, the restriction of the circumferential movement of the rotor 90 by the outer cam 70 is released, and the cam surface 82 and the cam receiving surface 93 coincide with each other.

[0062] When the pressure on the operating part 80 is released from the state where the cam surface 82 and the cam receiving surface 93 are aligned, the operating part 80 and the rotor 90 move backward due to the biasing force of the spring 6. At this time, the rotor 90 receives a component force from the inclined surface of the outer cam 70 and rotates around the central axis. That is, the inner cam 96 of the rotor 90 enters the first guide groove 71 from the inclined surface of the outer cam 70 and moves backward, so that the operating part 80 and the rotor 90 move backward. The backward movement of the operating part 80 and the rotor 90 is restricted by the locking protrusion 81 of the operating part 80 engaging with the locked part 76 provided at the rear end of the first guide groove 71 or the second guide groove 75 (FIG. 13(c)). Specifically, the head 88 of the locking protrusion 81 engages with the locked inclined surface 77 of the locked part 76, so that the backward movement of the operating part 80 and the rotor 90 is restricted. The head 88 has a shape complementary to the locked inclined surface 77 of the locked portion 76. In other words, the convex shape of the locked portion 76 is a shape complementary to a part of the locking protrusion 81. As a result, the writing part 4 of the refill 5 arranged in front of the rotor 90 is recessed into the barrel 3, and the knock-type writing instrument 11 is in a non-writing state.

[0063] According to the knock mechanism 60, when the stroke required for the knock operation is the same, the overall length of the outer cam in the axial direction can be made shorter than that of the knock mechanism 100 described in Patent Document 1. This will be described with reference to Figs. 12 and 15.

[0064] First, referring to FIG. 15(a) for the knock mechanism 100 described in Patent Document 1, the total length of the outer cam 131 is L1. The front end is the tip of the first protrusion 133 or the second protrusion 134, and the rear end is a surface corresponding to the abutment surface 26 with the cover member 50 in the knock-type writing instrument 1 according to the first embodiment. The stroke L0 required for the knock operation is equal to the distance between the tip of the inner cam 156 and the tip of the first protrusion 133 or the second protrusion 134. In the knock mechanism 100, the rotation of the operating part 140 around the central axis is restricted by the locking protrusion 141, which is short in the axial direction. Therefore, as shown in FIG. 15(b), the locking protrusion 141 is provided behind the cam surface 142 so as not to come off the first guide groove 132 or the second guide groove even when the operating part 140 advances by the knock operation. Therefore, in order to shorten the overall length of the outer cam 131, it is necessary to reduce the difference between L1 and L0.

[0065] Next, referring to FIG. 12(a) for the knock mechanism 60 in the second embodiment, the total length of the outer cam 70 is L5. As described above, the stroke L0 required for the knock operation is equal to the distance between the tip of the inner cam 96 and the tip of the first protrusion 72 or the second protrusion 73. In the knock mechanism 60, the rotation of the operating part 80 around the central axis is restricted by the locking protrusion 81 that is elongated in the axial direction. That is, the leg 87 of the locking protrusion 81 is always disposed between the locked part 76 and the first protrusion 72 of the outer cam 70, or between the locked part 76 and the second protrusion 73 during the knock operation, thereby restricting the rotation of the operating part 80 around the central axis. As a result, the head 88 of the locking protrusion 81 can be disposed at the front end of the operating part 80 near the cam surface 82.

[0066] Here, comparing the distance L1 of the outer cam 131 in Patent Document 1 with the distance L5 of the outer cam 70 in the second embodiment, the distance L5 is shorter than the distance L1 by approximately the distance L2 between the rear end of the locking protrusion 141 and the rear end face of the outer cam 131 in FIG. 15(a) and the distance L3 between the front end of the locking protrusion 141 and the crest 143 of the cam face 142. That is, the distance in FIG. 12(a) corresponding to the distance L2 in FIG. 15(a) corresponds to the distance between the rear end of the locking protrusion 81, i.e., the rear end of the head 88, and the abutting face 78, but is substantially zero because the locked portion 76 is wedge-shaped. Also, the distance in FIG. 12(a) corresponding to the distance L3 in FIG. 15(a) is substantially zero because the front end face of the locking protrusion 81, i.e., the front end face of the head 88, constitutes a part of the cam face 82. Therefore, according to the knock mechanism 60, compared to the knock mechanism 100 described in Patent Document 1, the overall length of the outer cam can be shortened by the distance L2 and the distance L3 in FIG. 15(a).

[0067] By shortening the overall length of the outer cam without changing the stroke of the knock operation, the overall knock mechanism can be shortened, and as a result, the overall length of the knock-type writing instrument can be shortened. Therefore, it is possible to provide a knock-type writing instrument having a knock mechanism that can meet various design and design requirements.

[0068] In the second embodiment, the locked portion 76 has a locked inclined surface 77. The head 88 of the locking protrusion 81 that locks with the locked inclined surface 77 also has a shape complementary to the locked inclined surface 77, i.e., a slope. Therefore, when assembling the knock type writing instrument 11, the operating part 80 can be smoothly inserted from the front of the barrel 3, improving the ease of assembly. The locked portion 76 can be provided at any position and in any shape (for example, a circular protrusion) on the side surface of the first protrusion 72 and the second protrusion 73 as long as it protrudes into the first guide groove 71 and the second guide groove 75. In contrast, the head 88 of the locking protrusion 81 can be configured as desired as long as it can be locked with the locked portion 76. In addition, the leg 87 of the locking protrusion 81 can be configured as desired so long as it is always positioned between the locked portion 76 and the first protrusion 72, or between the locked portion 76 and the second protrusion 73 of the outer cam 70 during the knocking operation, thereby restricting rotation around the central axis of the operating part 80.

[0069] Incidentally, characters such as the ball diameter of the ballpoint pen may be attached to the outer rear end surface 55 of the cover member 50 by printing by pad printing or attaching a sticker. The attached characters serve as a guide for aligning the orientation of the knock-type writing implements so that they are arranged in an orderly manner when displayed in a store. The barrel 3 has a clip 8 with a ball portion 7 (Figs. 1 and 8). It is preferable to make the distance between the barrel 3 and the ball portion 7 of the clip 8 narrower so that a thinner object, such as a piece of paper, can be clamped. It is preferable to make the draft angle at the time of molding the wide upper surface 9 (Fig. 3) of the clip 8 flatter, as this creates an aesthetic impression. It is preferable that the boundary portion between the tip member 2 and the barrel 3 is formed continuously and smoothly so that it cannot be recognized by the user. The front end of the spring 6 may be fitted to the inner surface of the tip member 2. In this case, even if the tip member 2 is removed from the barrel 3 when replacing the refill 5, the spring 6 is prevented from falling off and being lost.

[0070] The refill 5 may be a ballpoint pen, or other types of writing implements such as a marking pen, a touch pen, an eraser, etc. In addition, a part or the whole of the operating unit or the cover member 50 may be an erasing unit that erases handwriting made by a knock-type writing implement.

[0071] The refill 5 may be a ballpoint pen containing thermochromic ink. Here, the thermochromic ink refers to 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 thermochromic writing instrument using thermochromic ink, the second color is made colorless, and the term "erasing" refers to heating a line drawn in the first color (e.g., red) to make it colorless. Therefore, the friction member, which is the erasing part, rubs against the writing surface on which the line was drawn to generate frictional heat, thereby changing the drawn line to colorless, that is, erasing it. It should be noted that the second color may be a color other than colorless. [Explanation of symbols]

[0072] 1. Knock-type writing implement 10 Knock mechanism 20 Outer Cam 21 First guide groove 22 1st protrusion 23 Second protrusion 24 Second guide groove 30 Control section 31 Locking protrusion 32 Cam surface 35 Fitting hole 40 Rotor 43 Cam receiving surface 46 Inner Cam 50 Cover member 51 Fitting part

Claims

1. A knock-type writing instrument comprising a knock bar and a cover member covering a rear end face and an outer surface of the knock bar, a fitting hole is provided on a rear end surface of the knock bar, and a fitting portion protruding forward is provided on an inner rear end surface of the cover member, A knock-type writing implement, characterized in that the fitting portion is inserted into the fitting hole and fitted thereto, thereby fitting the cover member to the knock bar.

2. 2. The knock-type writing instrument according to claim 1, wherein a first locking portion is provided on an inner surface of the fitting hole, a second locking portion is provided on an outer surface of the fitting portion, and the first locking portion and the second locking portion are capable of locking with each other.

3. 3. The knock type writing implement according to claim 1, wherein the cover member is transparent or translucent.

4. 4. The knock type writing instrument according to claim 1, wherein a restricting protrusion is provided on an inner surface of the cover member, and a rear end surface of the knock bar is engaged with the restricting protrusion, thereby restricting the entry of the knock bar into the cover member.

5. 5. The knock type writing instrument according to claim 1, wherein the knock bar has an erasing portion capable of erasing handwriting made with the knock type writing instrument.

6. The knock-type writing instrument according to claim 5, characterized in that the knock-type writing instrument is a knock-type writing instrument having thermochromic ink, and the writing made with the thermochromic ink can be thermally discolored by frictional heat generated when rubbed by the erasing part.

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