JPH0217911Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is an invention related to preventing wobbling of cursive writing. In general, in writing instruments that protrude and retract the cursive by relative rotation of the tip and the cap,
For example, if a step is formed at the tip of a cursive body, and the diameter is larger on the rear end side, if this step is also provided in the tip shaft tip hole and pressed against this, the tip of the cursive will become stepped. Since the distance from the step part is short, the stepped part is fixed, thereby preventing the handwriting from wobbling when writing.

However, if a step cannot be formed on the tip side of the cursive body, the cursive body cannot be fixed, so the center of the cursive body is shifted from the center of the tip hole of the tip shaft, and the cursive body is placed on the inner edge of the hole of the tip tip of the tip shaft. A method has been used to prevent wobbling by bringing the cursive into contact with each other, but this has the disadvantage that it becomes difficult to protrude and store the cursive.

The purpose of the present invention is to solve these drawbacks, and in a writing instrument that protrudes or stores a writing instrument by relative rotation between the tip shaft and the cap, a protrusion is provided on the internal thread that holds the writing instrument, and the protrusion is provided inside the writing instrument. A tapered stepped portion is provided on the outer screw threadedly engaged with the screw, and a tapered step portion is provided which contacts the protruding portion and serves as a limit for advancement of the inner screw, and an appropriate gap is provided in the axial and radial directions at the threaded portion of the inner screw and the outer screw. As a result, with the protruding part of the internal screw in contact with the stepped part of the external screw, the axis center line of the internal screw and the writing body is slightly inclined with respect to the axis center line of the external screw and the tip axis, and the writing body is attached to the tip axis. The tip writing portion of the writing body is configured to protrude from the tip end hole while also contacting the inner surface of a guide hole arranged near the tip hole.

The following will be explained based on the illustrated embodiment. A joint tube 2 is installed in the tip shaft 1, and a mechanical stopper 3 is inserted into the inner diameter portion of the front end of the joint tube 2 and fixed integrally. There is. Further, the front end of a detent 4 is integrally inserted and fixed into the inner diameter portion of the rear end of the mechanism stop 3. An internal screw 6 holding a writing body 5 is inserted into the inner diameter portion of the rear end of the detent 4 so that it cannot rotate relative to the detent 4 and can only slide in the axial direction. A joint member 8 having a protrusion 7 on the outer diameter portion is integrally screwed onto the rear end of the internal thread 6. On the other hand, a threaded pipe 10 is integrally connected to the front end of the cap 9 located at the rear of the front shaft 1, and the rear end of an external thread 11 is fixed to this threaded pipe 10. The outer screw 11 fixes the connecting tube 12 to the front end while the threaded portion thereof is threadedly engaged with the threaded portion of the inner screw 6. A tapered step 13 is provided at a slightly forward position from the rear end of the outer screw 11, and the protrusion 7 of the inner screw 6 collides with this step 13, preventing the inner screw 6 from moving forward. become. The middle part of the detent 4 is inserted into the inner diameter part of the connecting tube 12, and the washer 1 is inserted into the front and rear ends of the connecting tube 12.
4 and 14' are in contact with each other. Further, a preload spring 15 is interposed between the washer 14 located at the front end of the connecting tube 12 and the outer diameter stepped portion of the mechanism stopper 3. The connecting cylinder 2, mechanism stop 3, and rotation stopper 4 are integrally fixed, and the external thread 11 and the connecting cylinder 1
It is rotatable relative to 2. The preload spring 15 generates a frictional force between the washers 14, 14' and both end surfaces of the connecting tube 12 when the connecting tube 12 rotates, thereby achieving constant rotational braking. In addition, the inner screw 6 cannot rotate with respect to the detent 4 and can only slide in the axial direction, and due to the relative rotational movement between the outer screw 11 and the detent 4, the inner screw 6 can rotate with respect to the outer screw 1.
1 and the rotation stopper 4 move in the axial direction, and the writing body 5 held by the internal screw 6 protrudes from the tip end hole of the tip shaft so that it can be stored. A suitable gap 17 is provided between the threaded portions of the internal thread 6 and the external thread 11 in the axial and radial directions. The cursive 5 has an internal thread 6 at its rear end.
When the outer screw 11 is rotated, it moves forward or backward together with the inner screw 6, and is protruded from or stored in the tip hole of the front shaft. The writing body 5 is inserted into the guide hole 16 of the mechanism stopper 3 disposed near the tip hole of the tip shaft. The inner diameter of this guide hole 16 is set to be slightly larger than the outer diameter of the writing body 5.

First, as shown in FIG. 3, when the writing body 5 is in the stored state, the inner screw 6 can move slightly in the axial and radial directions with respect to the outer screw 11 due to the gap 17 interposed therebetween. Next, by rotating the cap 9 with respect to the front shaft 1, the inner thread 6 is connected to the outer thread 11.
When the writing body 5 moves forward and protrudes from the tip end hole of the tip, the protruding part 7 of the internal thread 6 touches the stepped part 1 of the external thread 11.
3 in a line contact state as shown in FIG. 2 and is prevented from moving forward. When the inner screw 6 is advanced by the outer screw 11, the thread of the inner screw 6 and the outer screw 11
Since a part of the screw threads of the two must be in contact with each other, the contact portion of the screw threads will be offset from the center by the above-mentioned gap 17, and the writing body 5 and the internal screw 6 will have their axial centers centered around the guide hole 16. The line is slightly tilted with respect to the axis center line of the external screw 11, cap 9, and tip shaft 1, resulting in so-called center runout.
Therefore, when the writing body 5 protrudes from the tip end hole of the tip shaft, the writing body 5 comes into contact with the opposing inner surface portions of the guide hole 16 in a state of eccentricity, and the protruding portion 7 of the internal screw 6 is exposed to the outside. Since the writing body 5 comes into contact with the stepped portion 13 of the screw 11, the writing body 5 is securely fixed. Since the guide hole 16 is located close to the tip hole of the tip shaft, wobbling of the writing body 5 in the tip hole of the tip shaft during writing is prevented. Furthermore, when the writing body 5 is protruded, the writing body 5 is free until the protruding part 7 of the internal screw 6 comes into contact with the stepped part 13 of the external screw 11, and when the writing body 5 is stored, the internal screw 6 is free. Since the writing body 5 is free after the protruding portion 7 is separated from the stepped portion 13 of the external screw 11, the writing body 5 can be smoothly projected and stored.

The present invention is as described above, and a suitable gap is provided in the axial and radial directions at the threaded part of the internal thread and the external thread, so that the protruding part of the internal thread comes into contact with the tapered stepped part of the external thread. Sometimes, the axis center line of the cursive body is slightly inclined with respect to the axis center line of the tip axis so that the cursive body also comes into contact with the inner surface of the guide hole placed near the tip hole of the tip axis. This prevents the cursive writing from wobbling in the tip hole of the tip shaft when writing, and only when the internal screw is at its forward limit, its protrusion comes into contact with the stepped part of the external screw, otherwise the writing is free. Therefore, the protrusion and storage of the cursive writing can be carried out smoothly.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention.
The figure is a longitudinal sectional view, FIG. 2 is an enlarged sectional view of the main part when the writing body is protruded, and FIG. 3 is an enlarged sectional view of the main part when the writing body is stored. 1... Tip shaft, 2... Joint cylinder, 3... Mechanism stop,
4... Anti-rotation, 5... Cursive, 6... Internal screw,
7... Projection, 8... Joint member, 9... Cap, 10... Threaded pipe, 11... External thread, 12...
Connection tube, 13...Tapered stepped portion of external thread, 14,
14'... Washer, 15... Preload spring, 16
...Guide hole, 17...Gap.

Claims (1)

[Scope of utility model registration request] In a writing instrument that protrudes or stores a writing body by relative rotation of the tip shaft and the cap, a protrusion is provided on the internal screw that holds the writing body, and the external screw that is threadedly engaged with the internal screw comes into contact with the protrusion, and the internal screw moves forward. A state in which the protruding part of the internal thread is in contact with the stepped part of the external thread by providing a tapered step that restricts the internal thread and providing appropriate gaps in the axial and radial directions at the threaded part of the internal and external threads. With the inner screw and the center line of the writing body slightly inclined with respect to the outside screw and the center line of the tip shaft, the writing body is also in contact with the inner surface of the guide hole located near the tip hole of the tip shaft. A rotary feeding type writing instrument configured such that the tip writing part of the cursive body protrudes from the tip hole of the tip shaft.