CN211364058U - Pen instrument - Google Patents

Abstract

The utility model provides a pen tool, this pen tool can not rely on the mode of exerting of power to the frictional body, and the frictional body is firmly fixed and is restrained rotatoryly. A mounting hole which opens rearward of the shaft is provided at the rear end of the barrel of the pen, a friction body made of an elastic material is inserted into the mounting hole, an inward protrusion is formed on the inner peripheral surface of the mounting hole, an outward protrusion is formed on the outer peripheral surface of the friction body, and the outward protrusion and the inward protrusion are locked in the front-rear direction. The friction body has a friction portion projecting axially rearward from the rear end of the cylindrical body, and a front projection on the front end surface of the friction portion. The barrel has a rear protrusion on a rear end surface of the barrel. The front projection and the rear projection are engaged with each other in a rotational direction around the axis.

Description

Pen instrument

Technical Field

The utility model relates to a pen. More specifically, the present invention relates to a pen instrument in which a mounting hole opened rearward with respect to an axis is provided at a rear end portion of a cylindrical body such as an axis tube or a cap of the pen instrument, and a friction member is inserted into the mounting hole.

Background

Patent document 1 describes a mounting structure of a soft member in which a mounting hole opened axially upward is provided at an upper end portion of a tube body such as a barrel or a cap of a pen tool, and the soft member is inserted into the mounting hole, wherein an inward protrusion is formed on an inner peripheral surface of the mounting hole, an outward protrusion is formed on an outer peripheral surface of the soft member, and the outward protrusion passes over the inward protrusion from above downward.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2007-144991

SUMMERY OF THE UTILITY MODEL

The technique disclosed in patent document 1 is a configuration in which: the outer peripheral surface of the rear end portion of the small diameter portion (corresponding to the friction portion) of the soft member (corresponding to the present invention) (i.e., the outer peripheral surface of the connecting portion between the small diameter portion of the soft member and the shoulder portion of the large diameter portion (corresponding to the friction portion of the present invention)) forms a base portion of an inclined surface shape (i.e., a conical surface shape) whose outer diameter gradually increases as approaching upward. In particular, when the friction portion has a non-circular cross section, rotation is likely to occur.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a pen that is firmly fixed to a frictional body and is prevented from rotating during friction, regardless of the manner of applying force to the frictional body.

In the present invention, "rear" means the side of the friction member in the entire pen, and "front" means the side opposite to the side of the friction member. In addition, the present invention is configured such that the "pen tip entering state" means a state in which the pen tip enters the barrel, and the "pen tip protruding state" means a state in which the pen tip protrudes to the outside from the front end hole of the barrel.

The utility model provides a pen tool is provided with to axle rear open-ended mounting hole at the rear end of the barrel of the axle tube of pen tool or pen socket the friction body that is formed by elastic material is inserted in the mounting hole, a serial communication port the inner peripheral surface of mounting hole is formed with and is protruding inwards the outer peripheral face of friction body is formed with and is protruding outwards, protruding outwards with protruding in the front in the rear direction card inwards, the friction body possesses the follow the convex friction portion of rear end to axial rear of barrel, and the preceding terminal surface of friction portion possesses the place ahead arch, the barrel is in the rear end face of barrel possesses the rear arch, the place ahead arch with the rear arch meshes respectively in the direction of rotation that uses the axle center as the center.

In the pen of the present invention, the outer surface of the friction portion may have a non-circular cross-sectional shape.

The utility model discloses an among the pen tools, can be, the inner peripheral surface of the mounting hole of barrel has the circular form of cross section, the friction body possesses cartridge portion, cartridge portion follows friction portion set up and the cartridge to the place ahead body coupling in the mounting hole, the surface of cartridge portion has the circular form of cross section cartridge portion outer peripheral face forms outside protruding.

In the pen of the present invention, the insertion portion may include: a base part formed on the outer peripheral surface of the rear end part of the insertion part and not contacted with the inner peripheral surface of the opening edge of the mounting hole during non-friction; and a contact portion formed at a rear end portion of the base portion and contacting an inner peripheral surface of an opening edge of the mounting hole during rubbing.

The utility model discloses an in the pen tool, can be, cartridge portion still includes the intermediate part, the external diameter of intermediate part is set for and is less than the ratio of mounting hole the inside protrusion leans on the internal diameter of rear part, with than outside protrusion leans on the rear the outer peripheral face of cartridge portion with compare inside protrusion leans on the rear form annular space between the inner peripheral surface of mounting hole.

The utility model discloses an in the pen tool, can be, the arch possesses outwards: a guide part which is composed of an inclined surface with gradually increased outer diameter along with approaching to the rear; and an outer diameter portion formed rearward of the guide portion, the outer diameter portion of the outward protrusion being set to be larger than the inner diameter of the inward protrusion and smaller than the inner diameter of the mounting hole rearward of the inward protrusion.

In the pen of the present invention, the front end of the friction body may be formed with a shoulder portion capable of abutting against the opening end of the mounting hole, and the axial length of the rear end of the outward protrusion from the shoulder portion of the friction body is set to be greater than the axial length of the front end of the inward protrusion from the rear end of the cylinder body to the mounting hole.

In the pen of the present invention, the friction member may have an inner hole extending in the axial direction.

In the pen of the present invention, the front protrusion may be a pair of protrusions protruding forward from the friction portion, and each end portion in the circumferential direction may have an inclined surface, and the rear protrusion may be a pair of triangular protrusions protruding rearward from the rear end surface of the barrel.

In the pen of the present invention, the front protrusion may be a circumferential protrusion having an inclined surface protruding forward from the friction portion, and the rear protrusion may be a circumferential protrusion having an inclined surface protruding rearward from a rear end surface of the cylinder.

According to the present invention, in the pen tool, the inner peripheral surface of the mounting hole is formed with the inward protrusion, the outer peripheral surface of the friction member is formed with the outward protrusion, the outward protrusion engages with the inward protrusion in the front-rear direction, the friction member has the friction portion protruding from the rear end of the cylinder toward the axial rear direction, and the front end surface of the friction portion has the front protrusion, the cylinder has the rear protrusion on the rear end surface of the cylinder, and the front protrusion engages with the rear protrusion in the rotational direction around the axis center, thereby restraining the rotation of the friction member, and the friction member can be firmly fixed and restrained from rotating independently of the manner of applying force to the friction member.

According to the utility model discloses a pen tool can not rely on the mode of applying of power to the frictional body, and the frictional body is firmly fixed and is restrained rotatory.

Drawings

Fig. 1 is a longitudinal sectional view of a pen according to a first embodiment of the present invention.

Fig. 2 is an enlarged longitudinal sectional view of a main portion of fig. 1.

Fig. 3 is an enlarged longitudinal sectional view of a main portion of fig. 1.

Fig. 4 is an enlarged longitudinal sectional view of a main part at the time of friction of fig. 1.

Fig. 5 (a) is an enlarged front view of a pen (frictional body) according to a first embodiment of the present invention. Fig. 5 (b) is an enlarged side view of the pen tool (frictional body) according to the first embodiment of the present invention. Fig. 5 (c) is a sectional view taken along line a-a of fig. 5 (a). Fig. 5 (d) is a sectional view taken along line B-B of fig. 5 (a).

Fig. 6 is an enlarged perspective view of the pen (friction body) according to the first embodiment.

Fig. 7 (a) is an enlarged front view of a pen (friction body) according to a second embodiment of the present invention. Fig. 7 (b) is an enlarged side view of a pen (friction body) according to a second embodiment of the present invention. Fig. 7 (C) is a cross-sectional view taken along line C-C of fig. 7 (a). Fig. 7 (D) is a cross-sectional view taken along line D-D of fig. 7 (a).

Fig. 8 is an enlarged perspective view of the pen (friction body) according to the second embodiment.

Description of the reference numerals

1, a pen tool; 2, a cylinder body; 2a front axle; 2b an intermediate shaft; 2c a rear axle; 21 a front end hole; 22 a slide hole; 23 mounting holes; 24 are raised inwards; 24a guide part; 24b a minimum inner diameter portion; 25 rear convex; 3, a pen body; a 31 nib; 32 ink accommodating tubes; 4 an operation part; 41 an operating base; a ball portion 42; 43 shaft portions; 44 a clamp portion; 5a rotating member; 6, a spring pressing body; 7 a friction body; 71 an inner hole; 72 a friction part; 73 shoulder parts; 74 an insertion part; 75 are convex outwards; 75a guide part; 75b a maximum outer diameter portion; 76 an annular space; 77 a base portion; 78 a front projection; 79 contact portions; 8, paper surface; the axial length of A from the front end of the friction part to the rear end of the outward protrusion; b the axial length from the rear end of the barrel to the front end of the inward projection; c, axial clearance; a the outer diameter of the middle part of the insertion part; b inner diameter of the rear portion of the mounting hole that protrudes inward.

Detailed Description

Two embodiments of the present invention will be described below with reference to the drawings.

< first embodiment >

Fig. 1 to 6 show a first embodiment of the present invention.

The pen 1 of the present embodiment includes a cylinder 2, a pen body 3 accommodated in the cylinder 2, and an advancing and retracting mechanism for freely advancing and retracting a pen tip 31 of the pen body 3 from a front end hole 21 of the cylinder 2.

Pen body

The pen body 3 includes a pen tip 31, an ink containing tube 32 into which the pen tip 31 is press-fitted and fixed at a front end opening portion, a thermochromic ink filled in the ink containing tube 32, and a follower (for example, a high-viscosity fluid) which is filled at a rear end of the thermochromic ink and advances as the thermochromic ink is consumed.

The pen tip 31 may be any structure including, for example, a metallic ball-point pen tip that rotatably holds a ball at its tip, or a synthetic resin pen tip holder that holds the rear outer surface of the ball-point pen tip. A tail plug having a vent hole for allowing the ink accommodating tube 32 to communicate with the outside is attached to the rear end opening of the ink accommodating tube 32. A spring for pressing the ball at the tip forward is housed inside the pen tip 31. The spring is configured to include a rod portion at a front end portion of the compression coil spring, and the front end of the rod portion is in contact with the ball rear surface. When the ball pen is not used for writing, the ball is pressed against the inner surface of the inward front end edge of the front end of the ball-point pen tip by the forward biasing force of the spring, and the ink leakage from the front end of the pen tip 31 and the ink evaporation can be prevented.

Barrel body

The tubular body 2 includes a front thin cylindrical front shaft 2a, a cylindrical intermediate shaft 2b connected to a rear end portion of the front shaft 2a, and a cylindrical rear shaft 2c connected to a rear end portion of the intermediate shaft 2 b. Axially extending slide holes 22 are formed in the side walls of the cylindrical body 2 (for example, the side wall of the intermediate shaft 2b and the side wall of the rear shaft 2 c). A mounting hole 23 is axially provided through the rear end of the cylindrical body 2 (i.e., the rear end of the rear shaft 2 c). The friction body 7 made of an elastic material is press-fitted into the mounting hole 23. The friction member 7 is fixed to the rear end outer surface of the rear shaft 2c (the cylindrical body 2) without being interlocked with the axial movement of the operation portion 4. The friction body 7 and the operation portion 4 are independently provided. In addition, the barrel of the utility model can also be a barrel body such as a pen cap of a pen tool.

Rear projection

As shown in fig. 5, the cylindrical body 2 has a rear projection 25 on the rear end surface. The rear protrusions 25 in the present embodiment are a pair of triangular protrusions protruding rearward from the rear end surface of the cylindrical body 2. The rear protrusion 25 and a front protrusion 78 described later are engaged with each other in a rotational direction about the shaft center, whereby the rotation of the friction body 7 about the shaft center is suppressed regardless of the manner of applying force to the friction body 7. It is to be understood that the shape of the rear protrusion 25 is not limited to the illustrated shape, and may be, for example, a semicircular shape, a quadrangular shape, or other polygonal shapes, and the number thereof is not limited.

Inwardly projecting

An annular inward projection 24 is integrally formed on the inner peripheral surface of the mounting hole 23. The inward protrusion 24 has a guide portion 24a, and the guide portion 24a is formed of an inclined surface (i.e., a conical surface) whose inner diameter gradually decreases as it approaches the front. The inward protrusion 24 has a distal end surface formed by a surface perpendicular to the axis in front of the guide portion 24 a. A minimum inner diameter portion 24b formed by an acute angle portion is formed between the guide portion 24a and the distal end surface.

An in-out mechanism

The access mechanism is a side slide type access mechanism using a rotary cam mechanism. The advancing and retracting mechanism includes a cam portion formed on the inner surface of the intermediate shaft 2b, a rotating member 5 engaged with the cam portion and abutting against the rear end of the pen body 3, an operating portion 4 engaged with the rotating member 5 and protruding radially outward from the slide hole 22, and a biasing body 6 (e.g., a compression coil spring) accommodated in the cylinder body 2 and biasing the pen body 3 rearward. The advancing and retracting mechanism of the present embodiment is a double click type mechanism in which the operation unit 4 is slid forward both in the pen tip projecting operation and in the pen tip advancing operation. The rotating member 5 is formed of a molded body of synthetic resin (e.g., polyacetal resin).

The cam portion includes a plurality of saw-toothed cam teeth projecting forward and a plurality of cam grooves formed between the cam teeth and extending in the axial direction. The rotary member 5 has a plurality of (for example, 4) axially extending ribs on an outer surface thereof, and the ribs are fitted to the cam teeth of the cam portion and the cam grooves of the cam portion. At the front end of the shaft portion 43 of the operation portion 4, cam teeth that engage with the rear ends of the ridges of the rotary member 5 are formed by integral molding or attachment of a separate member.

Operation unit

The operation portion 4 includes an operation base 41 protruding radially outward from the axially extending slide hole 22 in the side wall of the cylindrical body 2. Further, the operation unit 4 includes: a shaft portion 43 which is connected to the operation base portion 41 and is axially movably accommodated in the cylinder 2; and a clip portion 44 connected forward to the operation base portion 41. The clip 44 can clip clothes such as a pocket. The operation portion 4 is obtained from a molded body of a synthetic resin (for example, a polycarbonate resin). A ball portion 42 is provided projecting from the back surface (inner surface) of the clip portion 44. The operation base portion 41 and the shaft portion 43, the operation base portion 41 and the clip portion 44, and the clip portion 44 and the ball portion 42 are formed integrally of one member or assembled of two separate members, respectively.

The operation base 41 is axially movable along the slide hole 22. By pushing the operation base 41 forward, the pen tip 31 of the pen body 3 can be freely inserted into and removed from the front end hole 21 of the cylinder 2.

Advancing or retracting the nib

When the operation base 41 of the operation portion 4 is slid forward against the backward urging force of the elastic pressing body 6 from the pen tip entering state, the cam teeth of the shaft portion 43 of the operation portion 4 press the rotation member 5 forward, the protrusion of the rotation member 5 moves forward along the cam groove, and accordingly the rotation member 5 presses the rear end of the pen body 3 forward, and the pen tip 31 protrudes from the front end hole 21 to the outside. At this time, the cam teeth of the shaft portion 43 come into contact with the projections of the rotary member 5, and the rotary member 5 rotates by a predetermined angle with respect to the cam portion. Thereby, the projection of the rotary member 5 is engaged with the cam teeth of the cam portion, and the pen tip is maintained in a projecting state.

When the operation base 41 of the operation portion 4 is slid forward from the pen tip projecting state, the shaft portion 43 of the operation portion 4 presses the rotary member 5 forward, the cam teeth of the shaft portion 43 come into contact with the ridges of the rotary member 5, and the rotary member 5 rotates at a certain angle with respect to the cam portion. Thereby, the engagement between the protrusion and the cam teeth of the cam portion is released, and the protrusion moves rearward along the cam groove of the cam portion by the rearward biasing force of the biasing body 6. The pen body 3 moves backward with the backward movement of the rotary member 5, and the pen tip enters the state.

Friction body

The friction body 7 includes a friction portion 72 and an insertion portion 74 integrally connected to the front of the friction portion 72, and is integrally formed of an elastic material. In the present embodiment, the frictional body 7 is a frictional color-changing member that thermally changes the color of the handwriting by wiping the surface of the thermally-changed handwriting. The outer surface of the friction portion 72 has a non-circular cross-sectional shape (see fig. 5 (c) or fig. 7 (c)). It is to be noted that the non-circular cross-sectional shape is not limited to the illustrated shape, and may be another polygonal shape such as a triangular shape, a quadrangular shape, or a hexagonal shape. Thus, by using an appropriate portion of the friction member, the handwriting of the thermochromic ink can be wiped off only at a portion intended by the user, and the excessive thermochromic behavior can be prevented.

The friction body 7 has an outward protrusion 75 formed on the outer peripheral surface thereof, and the outward protrusion 75 and the inward protrusion 24 are locked in the front-rear direction. The friction body 7 includes a friction portion 72 projecting axially rearward from the rear end of the cylindrical body 2, and a front protrusion 78 on the front end surface of the friction portion 72. The front protrusions 78 and the rear protrusions 25 are engaged with each other in the rotational direction about the shaft center, whereby the rotation of the friction body 7 about the shaft center is suppressed regardless of the manner of applying force to the friction body 7. The outward protrusion 75 and the inward protrusion 24 are locked in the front-rear direction, and the front protrusion 78 and the rear protrusion 25 are engaged with each other in the rotational direction about the axial center, whereby the friction body 7 can be firmly fixed to the cylindrical body 2.

Front projection

As shown in fig. 5, the friction body 7 includes a front protrusion 78 on the front end surface of the friction portion 72. The front protrusions 78 in the present embodiment are a pair of circumferential protrusions protruding forward from the friction portion 72, and each end in the circumferential direction is provided with an inclined surface. In other words, the friction member 7 includes a pair of triangular recesses rearward from the front end surface of the friction portion 72. The front protrusions 78 engage with the rear protrusions 25 in the rotational direction about the shaft center, thereby suppressing the rotation of the friction body 7 about the shaft center independently of the manner of application of force to the friction body 7. It is to be understood that the shape of the rear protrusion 25 is not limited to the illustrated shape, and may be, for example, a semicircular shape, a quadrangular shape, or other polygonal shapes, and the number thereof is not limited.

Fig. 5 is an enlarged view of the pen tool 1 (friction body 7) according to the first embodiment of the present invention, and fig. 6 is a perspective view of fig. 5. As shown in fig. 5 and 6, the friction member 7 is formed such that the cross-sectional shape of the friction portion 72 exposed from the cylindrical body 2 is substantially rectangular in a state of being attached to the cylindrical body 2 (rear shaft 2c) (fig. 5 (c)). Specifically, in the cross section, the apex of the rectangle is formed in the shape of a circular arc having a radius of curvature larger than that of the tip of the friction portion 72 of the friction body 7. Therefore, the cross section of the friction body 7 according to the first embodiment of the present invention is substantially rectangular, and when the short side of the substantially rectangular cross section is rubbed, the narrow range can be concentrated to rub, and when the long side of the substantially rectangular cross section is rubbed, the wide range can be rapidly rubbed, so that the rubbing operation intended by the user can be performed. The cross-sectional shape of the friction portion 72 is not limited to a substantially rectangular shape, and may be an ellipse, a quadrangle, a hexagon, or another polygon.

Preferably, the inner circumferential surface of the mounting hole 23 of the cylinder 2 has a circular cross-section, the friction member 7 includes an insertion portion 74 integrally connected forward from the friction portion 72 and inserted into the mounting hole 23, the outer surface of the insertion portion 74 has a circular cross-section, and an outward protrusion 75 is formed on the outer circumferential surface of the insertion portion 74. Thus, the friction body 7 is stably mounted in the mounting hole 23, and the front protrusion 78 and the rear protrusion 25 can be further firmly engaged with each other in the rotational direction about the axial center. However, the above-described structure is satisfied even if the injection-molded opening or the like is provided on the outer surface of the insertion portion 74, and the above-described effects are not hindered.

In the friction member 7, a base portion 77 is preferably formed on the outer peripheral surface of the rear end portion of the insertion portion 74, and the base portion 77 of the insertion portion 74 is preferably not in contact with the inner peripheral surface of the opening edge of the mounting hole 23 during non-friction. This reduces insertion resistance when the friction body 7 is inserted, and improves assemblability.

Preferably, the base portion 77 of the insertion portion 74 has a contact portion 79 that contacts the inner peripheral surface of the opening edge of the mounting hole 23 when rubbing the paper surface 8. This causes resistance between the base portion 77 of the insertion portion 74 and the inner peripheral surface of the opening edge of the mounting hole 23, and prevents the friction member 7 from unintentionally rotating about the axial center during friction.

Preferably, the cylinder 2 with the friction body 7 inserted therein is detachable with respect to the pen 1. This makes it possible to easily replace the friction body 7 with a new one when the friction body 7 is worn. In addition, the user can select and change a preferred shape of the friction body 7 for use. The cylinder 2, to which the friction body 7 is detachably inserted, is attached to the pen 1 by a detachable screw or fitting.

In the present embodiment, the elastic material constituting the friction body 7 is preferably a synthetic resin (rubber, elastomer) having elasticity, and examples thereof include: silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butylene-styrene copolymer), fluorine-based resin, chloroprene resin, nitrile resin, polyester-based resin, Ethylene Propylene Diene Monomer (EPDM), and the like. The synthetic resin having elasticity constituting the friction body 7 is preferably formed of an elastic material having low abrasion which hardly generates abrasion debris (wiping debris) at the time of friction as compared with a material composed of an elastic material having high abrasion (for example, an eraser or the like).

Friction part

The rear surface of the friction portion 72 is convexly curved. A shoulder 73 that can abut against the opening end of the mounting hole 23 (specifically, the rear end of the rear shaft 2c) is formed at the front end of the friction portion 72. The maximum outer diameter of the friction portion 72 is set to be larger than the inner diameter of the mounting hole 23 and smaller than the outer diameter of the rear end of the rear shaft 2 c.

Insertion part

An annular outward projection 75 is integrally formed on the outer peripheral surface of the distal end portion of the insertion portion 74. The outward protrusion 75 has a guide portion 75a, and the guide portion 75a is formed of an inclined surface (i.e., a conical surface) whose outer diameter gradually increases toward the rear. The outward projection 75 has a rear end face constituted by a face perpendicular to the axis. An acute angle is formed between the guide portion 75a and the rear end surface. The corner portion becomes the maximum outer diameter portion 75b of the outward protrusion 75. That is, the outward protrusion 75 includes: a guide portion 75a formed of an inclined surface whose outer diameter gradually increases toward the rear; and a maximum outer diameter portion 75b formed rearward of the guide portion 75 a.

The maximum outer diameter of the outward protrusion 75 is set to be larger than the minimum inner diameter of the inward protrusion 24 and smaller than the inner diameter b of the attachment hole 23 rearward of the inward protrusion 24. In the present embodiment, the maximum outer diameter of the outward protrusion 75 (i.e., the outer diameter of the maximum outer diameter portion 75b) is set to 4.9mm, and the minimum inner diameter of the inward protrusion 24 (i.e., the inner diameter of the minimum inner diameter portion 24b) is set to 4.1 mm. The difference between the maximum outer diameter of the outward protrusion 75 and the minimum inner diameter of the inward protrusion 24 is preferably in the range of 0.5mm to 2mm (preferably 0.5mm to 1 mm). This can reliably prevent the friction body 7 from falling off, and can realize smooth passing between the outward protrusion 75 and the inward protrusion 24.

An axially extending inner bore 71 is formed in the friction body 7. The front end of the inner hole 71 opens axially forward. The rear end of the inner hole 71 is located inside the friction portion 72. The friction body 7 is formed into a bottomed cylindrical shape with a closed rear end and an open front end by the inner hole 71. In the present embodiment, since the inner hole 71 is formed at least radially inward of the outward protrusion 75, the outward protrusion 75 is easily elastically deformed radially inward when the outward protrusion 75 moves over the inward protrusion 24.

Annular space

The intermediate portion of the insertion portion 74 (i.e., the portion between the outward protrusion 75 and the shoulder 73) has an outer diameter a smaller than the inner diameter b of the mounting hole 23 at the rear side of the inward protrusion 24. Thus, when the outward protrusion 75 abuts against the inward protrusion 24 immediately before the outward protrusion 75 passes over the inward protrusion 24, an annular space 76 is formed between the outer peripheral surface of the insertion portion 74 located rearward of the outward protrusion 75 and the inner peripheral surface of the attachment hole 23 located rearward of the inward protrusion 24.

As shown in fig. 2, even before the outward protrusion 75 passes over the inward protrusion 24, when the outward protrusion 75 and the inward protrusion 24 are strongly pressed against each other, the insertion portion 74 located rearward of the outward protrusion 75 is elastically deformed to bulge radially outward, and the annular space 76 is formed, so that the outer peripheral surface of the insertion portion 74 located rearward of the outward protrusion 75 is not strongly pressed against the inner peripheral surface of the mounting hole 23, and there is no possibility of resistance during insertion of the friction member 7. As a result, the outward protrusion 75 and the inward protrusion 24 can smoothly pass over each other. Specifically, the outer diameter a was set to 4.9mm, and the inner diameter b was set to 5.6 mm.

Axial clearance

As shown in fig. 3, an axial length a from the shoulder 73 of the friction body 7 to the rear end of the outward protrusion 75 (i.e., the maximum outer diameter portion 75B) is set to be slightly larger than an axial length B from the rear end of the rear shaft 2c to the front end of the inward protrusion 24 of the mounting hole 23 (i.e., the minimum inner diameter portion 24B) (refer to fig. 3). Thus, even if sliding between the outward protrusion 75 and the inward protrusion 24 is difficult when the outward protrusion 75 gets over the inward protrusion 24, the outward protrusion 75 can reliably get over the inward protrusion 24 without applying a lubricant or the like.

As shown in fig. 3, in a state where the insertion of the friction body 7 into the mounting hole 23 is completed, the rear end (i.e., the maximum outer diameter portion 75b) of the outward protrusion 75 is located forward of the front end (i.e., the minimum inner diameter portion 24b) of the inward protrusion 24, and an axial gap C is formed between the front end of the inward protrusion 24 and the rear end of the outward protrusion 75. The axial clearance C is effective particularly in the range of 0.05mm to 1.0mm (preferably 0.1mm to 0.5 mm). Due to the size of the axial clearance C, a large play in the axial direction does not occur when the friction body 7 is used, and a reliable passing between the inward protrusion 24 and the outward protrusion 75 when the friction body 7 is inserted can be achieved. In the present embodiment, specifically, the axial length a is set to 8mm, and the axial length B is set to 7.9 mm.

In addition, in a state where the outward protrusion 75 and the inward protrusion 24 have already passed over, the inward protrusion 24 is pressed against the outer peripheral surface of the insertion portion 74 located rearward of the outward protrusion 75. This prevents the insertion portion 74 from rattling in the axial and radial directions. In addition, in a state where the passing of the inward projections 24 and the outward projections 75 is ended, the rear end of the rear shaft 2c is pressed against the shoulder 73. This prevents the friction portion 72 from entering the mounting hole 23, and prevents the friction portion 72 from rattling in the radial direction.

< second embodiment >

Fig. 7 and 8 show a second embodiment of the present invention. This is a modification of the first embodiment, and is different from the first embodiment in the shape of the rear projection 25 and the front projection 78. Other structures and operational effects are the same as those of the first embodiment, and therefore, the description thereof is omitted.

Rear projection

As shown in fig. 7, the cylindrical body 2 has a rear projection 25 on the rear end surface. The rear protrusion 25 of the present embodiment is a circumferential protrusion having one inclined surface projecting rearward from the rear end surface of the cylindrical body 2.

Front projection

As shown in fig. 7, the friction body 7 includes a front protrusion 78 on the front end surface of the friction portion 72. The front protrusion 78 of the present embodiment is a circumferential protrusion having one inclined surface protruding forward from the friction portion 72. The outward protrusion 75 and the inward protrusion 24 are locked in the front-rear direction, and the front protrusion 78 and the rear protrusion 25 are engaged with each other in the rotational direction about the axial center, whereby the friction body 7 can be firmly fixed to the cylinder 2, and the rotation of the friction body 7 about the axial center can be suppressed regardless of the manner of applying force to the friction body 7.

Claims (10)

1. A pen tool, wherein a mounting hole opened rearward of an axis is provided at a rear end portion of a barrel of a pen holder or a shaft barrel of the pen tool, and a friction body made of an elastic material is inserted into the mounting hole,

an inward protrusion is formed on an inner peripheral surface of the mounting hole, an outward protrusion is formed on an outer peripheral surface of the friction body, the outward protrusion and the inward protrusion are locked in a front-rear direction,

the friction body has a friction portion projecting axially rearward from a rear end of the cylindrical body, and a front projection on a front end surface of the friction portion,

the cylinder body is provided with a rear bulge on the rear end surface of the cylinder body,

the front projection and the rear projection are respectively engaged in a rotation direction centering on the axis.

2. The pen of claim 1,

the outer surface of the friction part has a non-circular cross-sectional shape.

3. The pen tool according to claim 1 or 2,

the inner circumferential surface of the mounting hole of the cylinder has a circular cross-sectional shape,

the friction body is provided with an insertion part which is integrally connected from the friction part to the front and is inserted into the mounting hole,

the outer surface of the insertion part is circular in cross section, and the outward bulge is formed on the outer peripheral surface of the insertion part.

4. The pen tool of claim 3,

the insertion portion includes:

a base part formed on the outer peripheral surface of the rear end part of the insertion part and not contacted with the inner peripheral surface of the opening edge of the mounting hole during non-friction; and

and a contact portion formed at a rear end portion of the base portion and contacting an inner peripheral surface of an opening edge of the mounting hole during rubbing.

5. The pen tool of claim 4,

the insertion part also comprises a middle part,

the outer diameter of the intermediate portion is set smaller than the inner diameter of the portion of the mounting hole rearward of the inward protrusion, so that an annular space is formed between the outer peripheral surface of the insertion portion rearward of the outward protrusion and the inner peripheral surface of the mounting hole rearward of the inward protrusion.

6. The pen of claim 1,

the outward protrusion includes:

a guide part which is composed of an inclined surface with gradually increased outer diameter along with approaching to the rear; and

an outer diameter part formed at the rear of the guide part,

the outer diameter of the outer diameter portion of the outward protrusion is set to be larger than the inner diameter of the inward protrusion and smaller than the inner diameter of the mounting hole rearward of the inward protrusion.

7. The pen tool of claim 6,

a shoulder portion capable of abutting against the opening end of the mounting hole is formed at the front end of the friction body,

an axial length from a shoulder of the friction body to a rear end of the outwardly-projecting piece is set to be greater than an axial length from a rear end of the cylinder to a front end of the inwardly-projecting piece of the mounting hole.

8. The pen of claim 1,

an axially extending bore is formed in the friction body.

9. The pen of claim 1,

the front protrusions are a pair of circumferential protrusions protruding forward from the friction portion, and each end in the circumferential direction is provided with an inclined surface,

the rear protrusions are a pair of triangular protrusions protruding rearward from a rear end surface of the cylinder.

10. The pen of claim 1,

the front protrusion is a circumferential protrusion having an inclined surface protruding forward from the friction portion,

the rear projection is a circumferential projection having an inclined surface projecting rearward from a rear end surface of the cylindrical body.

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