JP4559741B2 - Knock-type writing instrument - Google Patents

Description

  The present invention relates to a knock-type writing instrument capable of causing a ballpoint pen refill to appear and disappear from an opening at the tip of a shaft cylinder by pressing a knock body.

  2. Description of the Related Art Conventionally, a knock-type writing instrument capable of causing a ballpoint pen refill to protrude and retract from an opening at the tip of a shaft cylinder by pressing a knock body is well known. This is disclosed in Japanese Unexamined Patent Publication No. 2003-63192 “Knock-type ballpoint pen”. In addition, such a knock-type writing instrument can replace the ballpoint pen refill disposed in the shaft cylinder by removing the front shaft such as the base and the front shaft and the rear shaft such as the crown and the rear shaft.

In the conventional knock type writing instrument, a ballpoint pen refill is urged toward the rear end side of the shaft cylinder by a coil spring and stored. The coil spring in this knock type writing instrument is arranged in a free length state in the shaft cylinder, and when the front shaft and the rear shaft are screw-fitted, the coil spring is compressed by a ball pen refill to obtain an urging force.
"Japanese Patent Laid-Open No. 11-78361" "Japanese Patent Laid-Open No. 2003-63192"

  However, in the conventional knock-type writing instrument, the length in the axial direction in which the coil spring is compressed from the free length state of the coil spring moves in the axial direction from the start to the end of screw fitting of the front shaft and the rear shaft. Because it was set longer than the distance, when removing the front shaft or the rear shaft to replace the ballpoint pen refill, the front shaft or the rear shaft is still a coil spring. In this state, if the front shaft or the rear shaft is lightly held, or if the hand is released from the front shaft or the rear shaft, the front shaft or the rear shaft jumps out.

  In particular, it is necessary to further compress the coil spring in order to press the knock body and project the tip of the ballpoint pen refill. As a result, the length in the axial direction for compressing the coil spring is longer than that in the state where the tip of the ballpoint pen refill is immersed, so that the front shaft or the rear shaft pops out when the ballpoint pen refill is replaced. It becomes easy to do.

  In view of these problems, it is conceivable to use a coil spring with a high spring multiplier and shorten the compression distance or to make the screw fitting distance between the front shaft and the rear shaft longer than the compression distance of the coil spring. Coil springs with high multipliers have a high operating load, which may lead to poor operability, and may cause a reverse flow phenomenon due to knock impact, and the coil outer diameter is large or the coil inner diameter is small. It is necessary to change the shape of the portion where the ball is disposed and the shape of the ballpoint pen refill. Further, when the screw fitting distance between the front shaft and the rear shaft is increased, new problems such as deterioration of assemblability and ball pen refill replacement occur.

  In view of the above problems, the present invention provides a knock type writing instrument having a conventional assembling mechanism and operability, and having good assemblability and exchangability so that the front shaft or the rear shaft does not pop out when the ballpoint pen refill is replaced. It is.

In order to achieve the above object, the present invention provides a coil in which a ballpoint pen refill slidably disposed in a shaft tube in which a front shaft and a rear shaft are detachably fitted with screws is disposed at the tip of the shaft tube. A spring mechanism is provided that urges and arranges in the rear end direction of the shaft cylinder by a spring and presses the knock body so that the tip portion of the ballpoint pen refill can protrude and retract from the opening portion of the shaft cylinder tip. A knocking-type writing instrument in which the ballpoint pen refill can be replaced by removing the screw fitting of the rear shaft, and the ballpoint pen refill is slidable on the inner wall on the tip end side of the shaft cylinder from the screw fitting portion of the front shaft. An inner diameter protrusion is formed, and the coil spring has an inner diameter part that contacts the ballpoint pen refill, and a rear end formed larger than the inner diameter of the protrusion, and the front shaft and the rear shaft Remove screw fitting And allows the coil spring, the front axle, to restrict the movement of the barrel rear end by said protrusion and Yes be disposed in a compressed state, a screw fitted to the rear axle and the front axle The ballpoint pen refill further compresses the coil spring and urges the ballpoint pen refill toward the rear end of the barrel after the start of the operation and before the end of the screw engagement between the front shaft and the rear shaft.

  INDUSTRIAL APPLICABILITY The present invention can provide a knock-type writing instrument that has a conventional retracting mechanism and operability and has good assemblability and interchangeability so that the front shaft or the rear shaft does not pop out when the ballpoint pen refill is replaced.

  In the knock type writing instrument, since the conventional screw-fitting structure and screw-fitting distance of the front shaft and the rear shaft are not changed, it is realized without impairing assembling property and exchangeability.

  1 to 8, a ballpoint pen refill 8 is coiled in a shaft cylinder in which a male screw portion O formed on a front shaft 2 and a female screw portion M formed on a rear shaft 3 are screw-fitted R. The spring 11 is housed in a state of being biased toward the rear shaft rear end 3a. A tip member 5 is screwed to the tip of the front shaft 2.

  The structure of the ballpoint pen refill 8 is known in the art. The ink for a ball pen (not shown) is directly stored in the ink storage tube 9, and a ball is placed at the tip of the ink storage tube 9. A ballpoint pen tip 10 that is held rotatably is mounted. A grip member 12 is integrally formed on the front shaft 2, and a clip member 13 is integrally formed on the rear shaft 3.

  The mechanism for projecting and retracting the tip of the ball-point pen tip 10 from the tip opening 5a of the tip member 5 is conventionally known. Briefly, the rotary cam 7 slides back and forth on the inner wall surface of the rear shaft 3. A cam groove K for guiding and rotating is formed, and a protrusion 7 a formed on the rotating cam 7 is engaged with the cam groove K and disposed. At the rear end of the rotary cam 7, there is a knock body 6 having a cam portion at the front end for sliding and imparting rotation to the rotary cam 7. The knock body 6 has a rear end outside the rear shaft rear end 3a. It is the structure arrange | positioned in the state protruded toward the direction.

  Specifically, as shown in FIG. 8, the cam groove K has a plurality of grooves (valley grooves T and recessed grooves M) having different lengths in the axial direction, and is formed between the individual grooves. The peak portions (T1, T2) to be formed are inclined surfaces. When the knock body 6 is pressed, the projection 7a of the rotary cam 7 is positioned in the valley groove T (short groove) formed by the step portions of the peak portion T1 and the peak portion T2 (FIG. 8-1). The tip protrudes, and when the knock body 6 is further pressed, the protrusion 7a rotates beyond the peak T2. ((FIGS. 8-2 and 8-3) Thereafter, the coil spring 11 is moved along the inclined surface (FIG. 8-4) by the urging force of the coil spring 11, and is positioned in the recessed groove M (long groove) (FIG. 8-5). The tip of the ball-point pen tip 10 is immersed in a state in which the protrusion 7a of the rotating cam is positioned in the recessed groove M.

  The coil spring 11 is restricted from moving toward the rear shaft rear end 3 a by a projection 4 having an inner diameter smaller than the outer diameter of the rear end portion of the coil spring formed in the front shaft 2, and As shown in FIGS. 4 and 5, the ball-point pen refill 8 is placed between the inner wall and the coil spring 11 before the screwing of the front shaft 2 and the rear shaft 3 is started. Not receiving the urging force. When the screw engagement between the front shaft 2 and the rear shaft 3 progresses, as shown in FIGS. 6 and 7, the ballpoint pen refill 8 comes into contact with the coil spring 11, and at the end of the screw engagement between the front shaft 2 and the rear shaft 3. The coil spring 11 is compressed by the ballpoint pen refill 8. At this time, the front shaft 2 and the rear shaft 3 with the projection 7a of the rotating cam 7 positioned in the trough T (short groove) or the projection 7a of the rotating cam 7 positioned in the recessed groove M (long groove). It is preferable to appropriately set the ballpoint pen refill 8 so as to start the compression of the coil spring 11 after starting the screw fitting R.

  Paradoxically, when the screw fitting R between the front shaft 2 and the rear shaft 3 is removed when the ballpoint pen refill 8 is replaced, as shown in FIGS. 4 and 5, the screw fitting between the front shaft 2 and the rear shaft 3 is performed. Before the removal is completed, the coil spring 11 abuts against the protrusion 4 and no urging force is generated on the ballpoint pen refill 8, so that the front shaft 2 and the rear shaft 3 are removed as shown in FIGS. Sometimes the ballpoint refill 8 does not pop out.

  By disposing the coil spring 4 in a compressed state between the protrusion 4 formed in the front shaft 2 and the inner wall of the tip of the tip member 5, the free length of the coil spring 11 is provided. Since it can be carried out without being limited by the mounting length or the like, it can be carried out with a spring multiplier and a compression distance equivalent to those of the conventional coil spring 11, and operability at the time of knocking can also be carried out similarly to the conventional one. Further, when the front shaft 2 and the rear shaft 3 are removed, such as when replacing the ballpoint pen refill, there is no possibility that the coil spring 11 falls and is lost.

  In this embodiment, for the sake of convenience, the protrusion is integrally formed in the front shaft, but it may be attached to the front shaft. The shape of the protrusion is not particularly limited, and any number of protrusions may be formed in a circumferential shape. In addition, the coil spring is disposed in a compressed state between the protrusion formed in the front shaft and the inner wall of the tip of the tip member, but the tip member and the front shaft are formed integrally. Also good.

  As mentioned above, although the present Example was explained in full detail, this invention is not limited to the said Example, A various change can be made within the range of the summary of this invention described in the claim.

  The knock type writing instrument of the present invention can be applied without being limited to the type of ink and the material and shape of the pen tip portion.

FIG. 3 is a longitudinal sectional view of a principal part, partially omitted, showing the knock type writing instrument of Example 1. It is a figure which shows the state which protruded the ball-point pen tip in FIG. It is a principal part enlarged view in FIG. It is a figure which shows the state before starting the screw fitting of a front axis | shaft and a rear axis | shaft. It is a principal part enlarged view in FIG. It is a figure which shows the state in the middle of screw fitting of the front shaft and the rear shaft. It is a principal part enlarged view in FIG. It is a figure explaining the latching relationship of the cam groove and protrusion of a rotation cam in the retracting operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Knock type writing instrument 2 Front shaft 3 Rear shaft 4 Protrusion 6 Knock body 7 Rotating cam 8 Ball pen refill 10 Ball pen tip 11 Coil spring O Male thread part M Female thread part R Thread fitting

Claims (1)

A ball pen refill slidably disposed in a shaft cylinder in which the front shaft and the rear shaft are detachably screwed is urged toward the rear end of the shaft cylinder by a coil spring disposed at the tip of the shaft cylinder. By disposing a screw fitting between the front shaft and the rear shaft, the front and rear shafts are provided with a projecting and retracting mechanism capable of projecting and retracting the tip of the ballpoint pen refill by pressing the knock body. A knock-type writing instrument in which the ballpoint pen refill can be exchanged , wherein a protrusion having an inner diameter on which the ballpoint pen refill is slidable is formed on the inner wall of the front end of the shaft from the screw fitting portion of the front shaft, and the coil spring The coil spring has an inner diameter portion that abuts on the ballpoint pen refill and a rear end portion formed larger in diameter than the inner diameter of the protrusion, and the screw spring between the front shaft and the rear shaft is removed. The Serial to front axle, to restrict the movement of the barrel rear end by said protrusion and Yes be disposed in a compressed state, after the start of the rear axle of the screw mating with the front axle and the front axle Before the end of screw fitting of the rear shaft, the ballpoint pen refill further compresses the coil spring and urges the ballpoint pen refill toward the rear end of the shaft cylinder.

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