JPH0664968U - Writing instrument - Google Patents

Abstract

(57) [Abstract] [Purpose] In a Kernknock type writing instrument in which the inner cylinder 12c is positioned by the coil spring 13, the vibration of the coil spring 13 is effectively prevented with an inexpensive structure. A rib 15 having an inscribed diameter substantially the same as the outer diameter of the coil spring 13 is formed at a position facing at least a part of the coil spring 13 on the inner surface of the shaft cylinder 11 to restrict the displacement of the coil spring 13.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a Kernknock type writing instrument, and in particular, the vibration prevention of the writing instrument positioned in the upper portion of the shaft cylinder by being pressed by a coil spring arranged along the inner surface of the shaft cylinder of the inner cylinder forming the Kernknock mechanism. Regarding

[0002]

[Prior art]

 Generally, in a Kernknock writing instrument, in order to ensure the assemblability, the inner cylinder forming the Kernknock mechanism is pressed against the inner surface of the upper barrel by a coil spring arranged along the inner face of the barrel. Positioning is performed in the upper part of the barrel.

However, with such a configuration, when the Kernknock mechanism operates (when the rotor of the Kernknock mechanism rotates with respect to the inner cylinder by the action of the cam, the pen tip protruding / retracting state switches). The shock may cause the coil spring to resonate, which may cause an unpleasant sound, or may give an unpleasant vibration to the finger of the user who operates the knock portion.

Therefore, as a technique for preventing this vibration, the following techniques (a) and (b) have been conventionally implemented.

(A) By changing the wire diameter or the number of turns of the coil spring, its natural frequency is adjusted to avoid resonance.

(B) As shown in FIGS. 5, 6, and 7, the outer circumference of the coil spring 3 is covered with a stretchable synthetic resin tube 9 to restrict the movement of the coil spring 3.

[0007]

[Problems to be solved by the device]

 However, first, the technique of (a) above has a problem that the effect is insufficient because it does not regulate the movement of the coil spring, and the specifications of the coil spring are special, resulting in a high cost. Also in the technique (b), the number of parts is increased, so that the assembly cost as well as the material cost is increased, which also leads to a high cost.

The present invention has been made by paying attention to the problems of the conventional technique, and is a Kernknock type writing instrument in which the inner cylinder is positioned by a coil spring, and the vibration of the coil spring is inexpensive. The purpose is to provide a writing instrument that is effectively prevented by the configuration.

[0009]

[Means for Solving the Problems]

 The gist of the present invention for achieving such an object is a writing instrument for retracting a pen tip (18a) by a Kern knock mechanism (12), and an inner cylinder (12c) constituting the Kern knock mechanism (12). In the writing instrument positioned by being pressed by a coil spring (13) arranged along the inner surface of the barrel (11) and positioned in the upper part of the barrel (11), a diameter substantially equal to the outer diameter of the coil spring (13). The writing instrument is characterized in that the rib (15) having the inscribed diameter is formed at a position facing at least a part of the coil spring (13) on the inner surface of the barrel (11).

[0010]

[Action]

 When the knock portion (11a) above the shaft cylinder (11) is pushed down and the Kern knock mechanism (12) is activated, the cam of the rotor (12b) of the Kahn knock mechanism (12) works together (inner cylinder (12c)). ) The shock when riding over the cam becomes vibration and is transmitted to the coil spring (13). However, since the outer diameter of the coil spring (13) is pressed by the ribs (15) arranged in the barrel (11), the damping of the coil spring (13) is fast and the unpleasant vibration of the coil spring (13) is effectively prevented.

[0011]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the writing instrument of the present embodiment has a Kernknock mechanism 12 in the upper part of the barrel 11 and inside the barrel 11 and a barrel 14 and a cap 16 which are sequentially fixed to the tip side thereof. The refill 18 is housed in a state of being urged upward by the refill coil spring 17, and the coil spring 13 for positioning the inner cylinder 12c constituting the Kernknock mechanism 12 and the shaft for preventing the coil spring 13 from vibrating. A rib 15 formed on the inner surface of the cylinder 11 is provided. Note that FIG. 1 shows a state in which the refill 18 is extended (the pen tip 18a is extended).

The Kern knock mechanism 12 includes a knock rod 12a which is urged upward at the upper end of the shaft cylinder 11 and is vertically movable, and is pushed down by operating the knock portion 11a, and a lower end of the knock rod 12a. Is a slidably fitted upper part and an upper end of the refill 18 is inserted in a lower part, and a rotor 12b which receives the upper end of the refill 18 and fits into the inner cylinder 12c to move up and down. It is a composition.

According to the Kern knock mechanism 12, the cam is provided between the inner surface of the inner cylinder 12c and the outer peripheral surface of the rotor 12b, and between the upper surface of the rotor 12b and the lower surface of the knock rod 12a. By the action of the cam, the rotor 12b, which is pushed down by the knock bar 12a and descends, rotates by a predetermined angle each time it descends and returns, and alternately stops at two upper and lower positions. 18a (pen tip) appears and disappears.

The coil spring 13 is arranged along the inner circumference of the shaft cylinder 11 (or the outer circumference of the refill 18) between the lower end surface of the inner cylinder 12c and the upper end 14a of the front cylinder 14, and 14 is screwed into the tip of the barrel 11 and is compressed when it is mounted. By pushing the inner barrel 12c against the step 11c formed on the inner surface of the upper portion of the barrel 11, the inner barrel 12c is moved to a predetermined position. It is to hold it in position.

As shown in FIGS. 2 to 4, the rib 15 is formed along the axial direction of the barrel 11 at a position facing substantially the entire length of the coil spring 13, and a plurality of ribs 15 are formed at a predetermined pitch in the circumferential direction. ing. The inscribed diameter of the rib 15 may be set to be substantially equal to the outer diameter of the coil spring 13, but the inscribed diameter of the rib 15 is slightly smaller than the rib 15 so as to come into contact with the outer circumference of the coil spring 13 with a slight force. It is preferably set small.

Next, the operation will be described. In the above writing instrument, when the knock portion 11a is operated, the pen tip 18a appears and disappears as usual due to the operation of the Kern knock mechanism 12. However, when the cam of the rotor 12b goes over the cam on the inner surface of the inner cylinder 12c, the impact is generated by the coil spring. Even if it is transmitted to the coil spring 13, the rib 15 is provided on the outer peripheral portion of the coil spring 13 and the displacement of the coil spring 13 is restricted, so that the vibration of the coil spring 13 is prevented. Moreover, since the rib 15 integrally formed on the inner surface of the shaft cylinder 11 prevents the coil spring 13 from vibrating, there is no increase in the number of parts and the number of assembling steps.

Therefore, an adverse effect due to the vibration of the coil spring 13, particularly, generation of an unpleasant sound or vibration due to resonance is prevented by an inexpensive structure, and a comfortable operation feeling is given to a person who uses the writing instrument while maintaining low cost. Will be able to.

The present invention is not limited to the above embodiment. For example, the rib 15 need not be formed over the entire length of the coil spring 13, but may be formed over a part thereof.

[0019]

[Effect of device]

 According to the writing instrument of the present invention, the ribs formed integrally on the inner surface of the shaft cylinder restrict the movement of the coil panel and prevent its vibration. Therefore, the number of parts and the number of assembling steps are not increased at all, and it is possible to give a comfortable operation feeling to a person who uses the writing instrument while maintaining the low cost.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a barrel showing a rib according to an embodiment of the present invention.

FIG. 3 is a horizontal sectional view of a barrel showing a rib according to an embodiment of the present invention.

FIG. 4 is a horizontal sectional view showing an embodiment of the present invention.

FIG. 5 is a vertical sectional view showing a conventional writing instrument.

FIG. 6 is a perspective view showing a conventional vibration prevention structure for a writing instrument.

FIG. 7 is a horizontal sectional view showing a conventional writing instrument.

[Explanation of symbols]

 11 ... Shaft cylinder 12 ... Kahn knock mechanism 12a ... Knock rod 12b ... Rotor 12c ... Inner cylinder 13 ... Coil spring 15 ... Rib 18 ... Refill

Claims (1)

[Scope of utility model registration request] 1. A writing instrument for retracting and retracting a pen tip by a Kern knock mechanism, wherein an inner cylinder constituting the Kern knock mechanism is pressed by a coil spring arranged along the inner surface of the barrel and positioned in the upper portion of the barrel. In the writing instrument, the rib having an inscribed diameter substantially the same as the outer diameter of the coil spring is formed at a position facing at least a part of the coil spring on the inner surface of the shaft cylinder.