JP2006305862A - Axial body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial body, in which a resilient member can be correctly assembled to a barrel and, at the same time, can be prevented as much as possible from falling off the barrel. <P>SOLUTION: In the barrel, within which a retracting and extending body energized by the resilient member is movably arranged, an elastic covering body is arranged at a portion, which belongs to the barrel and serves for gripping and, at the same time, connectingly formed onto the inner surface of the barrel so as to hold the resilient member by the covering body formed onto its inner surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shaft tube in which a projecting / retracting body urged by a resilient member is movably disposed in the shaft tube.

As an example, a writing instrument in which a writing body such as a ballpoint pen is arranged in a shaft cylinder so as to appear and disappear will be described. A ballpoint pen refill urged rearward by a coil spring is disposed in the shaft cylinder. A retracting mechanism generally referred to as a debit cam is disposed behind the ballpoint pen refill and at the rear of the shaft cylinder. The ballpoint pen refill is caused to appear and disappear from the tip of the shaft tube by moving the pressing body of the debit cam back and forth.
Usually, the coil spring is not fixed in the shaft tube, and is inserted in a free state. This is because of the ease of assembly.
However, due to the consumption of the ballpoint pen refill, when the ballpoint pen refill is replaced, the coil spring also comes off from the shaft tube, which is a troublesome replacement work. Sometimes the coil spring was lost.

JP-A-8-142578. Japanese Utility Model Publication No. 06-045794.

  Therefore, in order to prevent the coil spring from coming off from the shaft cylinder, a protrusion or the like for fixing the coil spring is formed on the inner surface of the shaft cylinder, and one end of the coil spring is press-fitted and fixed to the protrusion. It was done. However, when the coil spring is assembled to the shaft tube, it is sometimes not fixed completely but fixed in an inclined state. Because of the thin and long shaft cylinder, it is difficult to accurately press-fit into a deep part. When the coil spring is assembled in an inclined state, the coaxiality of the shaft cylinder, the coil spring, and the ballpoint pen refill is shifted. If you rub or force it, the writing part of the most important ballpoint pen refill will come into contact with the inner wall surface of the shaft tube, which not only deteriorates the feeling of operation but also damages the important writing part. There was a risk of getting lost.

  The present invention is a shaft cylinder in which a projecting and retracting body urged by an elastic member is movably disposed in a shaft cylinder, and an elastic covering body is disposed on a portion gripped by the shaft cylinder. The gist is that the covering body is connected to the inner surface of the shaft tube, and the elastic member is held by the covering body formed on the inner surface.

  The present invention is a shaft cylinder in which a projecting and retracting body urged by an elastic member is movably disposed in a shaft cylinder, and an elastic covering body is disposed on a portion gripped by the shaft cylinder. Since the covering body is connected to the inner surface of the shaft cylinder, and the elastic member is held by the covering body formed on the inner surface, the elastic member can be accurately assembled to the shaft cylinder. Can be prevented from falling off as much as possible.

As an example of the above-mentioned appearance body, various examples such as writing instruments such as mechanical pencils, ballpoint pens, correction pens, tools such as cutters, engraving swords, drivers, input pens used in PDA (Personal Digital Assistance) and electronic notebooks, etc. Is mentioned.
Hereinafter, an example in which a ballpoint pen is arranged so as to be able to appear and retract in a shaft cylinder will be described. A ballpoint pen refill 2 containing water-based ink or oil-based ink is arranged inside the shaft cylinder 1 so as to be movable back and forth. The ballpoint pen refill 2 is always urged in the immersion direction by an elastic member 3 such as a coil spring, but the ballpoint pen refill 2 is advanced by operating a debit cam 4 disposed behind the shaft tube 1. The protruding state can be maintained. The debit cam 4 includes a rotor 5 that receives the rear end of the ballpoint pen refill 2 and a slider 6 that rotates and advances the rotor 5. A pressing portion 6a protruding from the rear end of the shaft cylinder 1 is integrally formed. The ballpoint pen refill 2 includes a tank unit 7 for storing ink, a chip holder 8 connected to the front end of the tank unit 7, a chip 9 connected to the front end of the chip holder 8, and a tip of the chip 9. It is composed of a ball 10 or the like that is rotatably arranged and serves as a writing unit.

The shaft cylinder 1 is composed of a front shaft 1a and a rear shaft 1b, and the front shaft 1a and the rear shaft 1b are detachably connected by means such as screwing. They may be connected with each other, and may be formed as one shaft body instead of being divided. In the present example, the ballpoint pen refill 2 is configured to be easily replaceable, and is composed of a front shaft 1a and a rear shaft 1b, which are detachable. Further, the front portion of the front shaft 6 has a conical shape (conical portion 11) that is tapered toward the front end. And the through-hole 12 is formed in the intermediate part of the cone part 11 in the position which is partially but equally spaced, and the inner surface part of the grip member mentioned later has entered. In this example, the through-holes 12 are formed at two opposing positions, but the present invention is not limited to this and may be formed at, for example, four positions. In this example, the fan shape is long in the circumferential direction, but may be rectangular or square, or may be long in the vertical direction. The conical portion 11 is formed with an in / out hole 13 through which the tip 9 protrudes / inverts, and a front end portion of the in / out hole 13 is formed with a reduced diameter portion 14 substantially the same shape as the outer shape of the tip 9. A slight gap is formed.
On the other hand, a grip member 15 made of an elastic body is covered from the intermediate portion of the front shaft 1a to the conical portion 11. The grip member 15 is integrally formed with the front shaft 1a by two-color molding or insert molding in consideration of productivity, but the grip member 15 may be formed as a separate member and fitted into the front shaft 1a.
The grip member 15 is made of a rubber material such as urethane rubber, ethylene acrylic rubber, epichlorohydrin rubber, acrylic rubber, ethylene propylene rubber, chloroprene rubber, natural rubber, isoprene rubber, chlorinated polyethylene, nitrile rubber, or silicone rubber. May be elastomers such as styrene elastomers, olefin elastomers, ester elastomers, urethane elastomers, acrylic resins, silicone resins, fluororesins, vinyl chloride, urethane resins, polyurethane resins, polyethylene resins, elastomers It may be an elastic resin such as gel or polyethylene gel.
Further, the hardness is preferably set to 30 to 70 degrees in Shore A hardness, but substantially the same effect can be obtained even if it is set to 5 to 80 degrees.

  A front inner surface portion of the grip member 15 is connected to the inner surface of the front shaft 1a through the through hole 12 of the conical portion 11 of the front shaft 1a. And the part (inner surface protrusion part 16) which protruded to the inner surface of the front axis | shaft 1a is contacting in the state which buried the outer shape part of the said elastic member 3 about 1/3. That is, the inner surface protruding portion 16 is a portion that holds the elastic member 3 and prevents the shaft tube 1 from falling off. In this example, two turns of the coil spring which is the elastic member 3 are held by the inner surface protruding portion 16, but the present invention is not limited to this. Although it is good, there is also a risk of reducing the action as a coil spring. Therefore, it is preferable to hold about 2 turns as in this example. In addition, although the conical part 17 which expands toward the rear part is formed in the rear part of the internal surface protrusion part 16, it considers the assembly | attachment property with respect to the front shaft 1a of the elastic member 3, and an elastic member 15 is a conical portion 17 for smoothly guiding and holding the inner surface protruding portion 16 on the inner surface protruding portion 16. When the elastic member 3 is assembled to the inner surface protruding portion 16, the front end portion of the elastic member 3 is guided by the conical portion 17, and the inner surface protruding portion 16 is accurately positioned while being elastically deformed. Here, even if the elastic member 3 is assembled with a slight inclination, it is gradually guided to an appropriate position by elastic deformation of the inner surface protruding portion 16.

Further, a holding portion 18 having an inner diameter slightly smaller than the outer diameter of the front portion of the tip holder 8 of the ballpoint pen refill 2 is formed in front of the inner surface protruding portion 16. That is, when the ball-point pen refill 2 is protruded from the shaft cylinder 1, the front portion of the chip holder 8 comes into contact with the holding portion 18 (see FIG. 5). Then, by bringing the front portion of the chip holder 8 into contact with the elastically deformable holding portion 18, the chip holder 8 is bent during writing, and as a result, the feeling of writing with a brush is obtained. Considering the bending of the chip holder 8, the grip member 15 preferably has a hardness of 30 to 80 degrees. Below 30 degrees, depending on the user's preference, the amount of deformation of the writing part increases when writing, and a sense of incongruity appears, and above 80 degrees, the bending of the chip holder 8 is not obtained and a hard writing feeling is obtained. It will be.
Further, by holding the tip holder 8 with the elastically deformable holding portion 18, it is possible to prevent the ball pen refill 2 from rattling against the shaft tube 1 and fine vibrations that occur during writing.
Furthermore, in this example, since the grip member 15 is formed up to the conical portion 11 of the front shaft 1a, it can be sufficiently adapted to a user who holds and writes the front portion of the shaft tube 1. ing.

The front external view which shows an example of this invention. The longitudinal cross-sectional view of FIG. The principal part enlarged view of FIG. AA line sectional view of Drawing 3. The principal part longitudinal cross-sectional view which shows the state which the ball-point pen refill protruded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Ball-point pen refill 3 Repellent member 4 Debit cam 5 Rotor 6 Slider 7 Tank part 8 Tip holder 9 Tip 10 Ball 11 Conical part 12 Through-hole 13 Intrusion hole 14 Reduced diameter part 15 Grip member 16 Inner surface protrusion part 17 Conical part 18 Holding part

Claims (3)

A shaft cylinder in which a retractable body urged by an elastic member is movably disposed in a shaft cylinder, and an elastic covering body is disposed on a portion gripped by the shaft cylinder, and the covering body is A shaft body formed by connecting to an inner surface of a cylinder and holding the elastic member by a covering formed on the inner surface. The shaft body according to claim 1, wherein a covering body formed on the inner surface and an intruding body are brought into contact with each other. The shaft body according to claim 1, wherein the shaft body and the covering body are formed by two-color molding or insert molding.

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