JP2006038113A - Thread-engagement structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thread-engagement structure for a male screw and a female screw, in which the male screw and the female screw can be easily combined without breaking each other. <P>SOLUTION: In this thread-engagement structure for the male screw and the female screw, a slit is formed in the female screw, and a guide cylinder is provided to cover the outer circumference of the female screw. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a screwed structure of a male screw and a female screw.

  As an example, a holder in which a small-diameter screw cylinder having a thread on the inner surface is formed at the tip of a cylindrical rotary sleeve via a stepped portion and a writing instrument such as an eraser or a writing instrument is attached to the receiving part is provided as the rotary sleeve. A cylindrical portion that is fitted in the axial direction so as to be movable, is threadedly engaged with the screw tube at the tip of the receiving portion of the holder, and is formed on the outer periphery of the tip of the cylindrical portion. Protrusions that can be engaged with the edges are formed, and slits are provided at the tip of the cylindrical portion so that the protrusions can be bent inward, so that the rotating sleeve can be rotated at the rear end of the cursive body. There is known a rotary retracting device which is attached and can be moved in the axial direction of the cylindrical portion of the holder but is prevented from rotating with respect to the writing body. That is, while the tip of the slit portion of the holder is slightly bent inward, the thread of the rotating sleeve is engaged with the thread groove beyond the protrusion of the holder, and thereby the holder (male thread) and the rotating sleeve (female thread). Is assembled.

Japanese Patent Publication No. 7-61758 (Claims, page 2, line 28 to line 32).

However, in the above prior art, when assembling the holder (male screw) and the rotating sleeve (female screw), there is a fear that the portion where the slit is not formed excessively is inserted. There was a risk of crushing the part. In order to prevent this excessive insertion, attempts have been made to insert carefully, but the productivity has been significantly reduced.
In addition, it is conceivable to form a slit over the entire length of the holder here, but the male screw part is easily bent toward the inside of the holder, and even if it is screwed with a rotating sleeve (female screw), Since the screwing force is weak and strong, when the writing pressure is applied to the writing instrument, the screwing is easily released and there is a risk of being immersed.

  The gist of the present invention is a screwed structure of a male screw and a female screw, and a slit is formed in the female screw.

  The present invention is a screwed structure of a male screw and a female screw, and since the slit is formed in the female screw, it is possible to provide a screwed structure that does not break down as well as easily assemble the male screw and the female screw.

A rotating shaft 2 that is rotatable relative to the shaft tube 1 but cannot be moved back and forth is inserted in the rear portion of the shaft tube 1, and this rotating shaft 2 corresponds to the female screw of the present invention. . More specifically, a concave portion 3 is formed on the inner surface of the rear portion of the shaft cylinder 1, and a convex portion 4 on the circumference formed in an intermediate portion of the rotating shaft 2 is formed in the concave portion 3. Is engaged. Further, the vicinity of the rear portion of the rotating shaft 2 protrudes from the rear end opening 1a of the shaft tube 1, and a clip 5 is formed on the protruding portion 2a. On the other hand, the rotating shaft 2 has a cylindrical shape, and a front portion thereof is a small-diameter cylindrical portion 2 b having an outer diameter slightly smaller than the inner diameter of the axial tube 1. An inner surface protrusion 6 is formed on the front inner surface of the small diameter cylindrical portion 2b. The inner surface protrusion 6 is a female screw portion of the present invention, and is screwed and engaged with a spiral groove of a spiral member described later. In addition, a slit 2c is formed on the side surface of the small-diameter cylindrical portion 2b so as to face the same, but the inner projection 6 is located on the same circumference as the slit 2c. Further, a protrusion 2d that contacts and slides with the inner peripheral surface of the shaft tube 1 is formed on the outer periphery of the small diameter portion 2b so as to face the same, but the protrusion 2d is also formed on the same circumference as the slit 2c. ing. That is, the protrusion 2d and the inner surface protrusion 6 are formed on the circumference in the area of the slit 2c. The slit 2c is formed at a position where it is easily subjected to the elastic deformation action of the small diameter portion 2b.
Further, a circumferential rib 2e and a slit 2f are formed above the small diameter portion 2b so as to be orthogonal to the rib 2e. A rib 2e slidably in contact with the inner surface of the shaft tube 1 is provided with elasticity by a slit so that the sliding resistance between the shaft tube 1 and the rotating shaft 2 can be adjusted.
A reduced diameter portion 7 is formed on the front inner surface of the shaft tube 1, and a guide groove 8 is formed in the reduced diameter portion 7 in the longitudinal (vertical) direction. The guide groove 8 is formed at an opposed position. A plate-like vertical rib 9 that is relatively thin as compared with the thickness of the shaft tube 1 is formed in front of the guide groove 8, that is, on the inner surface near the front end of the shaft tube 1. The vertical ribs 9 are also formed at opposing positions. An arc portion 10 is formed on the top of the vertical rib 9. It is a means made to prevent damage to the surface of the rod-like body that may come into contact.

A spiral member 11 corresponding to the male screw of the present invention is disposed inside the rotating shaft 2 so as to be movable back and forth. Hereinafter, the spiral member 11 will be described. The spiral member 11 has a cylindrical shape (hollow portion 12), and a male screw portion 13 is formed on the outer surface. The male screw portion 13 is engaged with the inner surface protrusion (female screw portion) 6 of the rotating shaft 2. A holding portion 15 for detachably holding the rod-like body 14 is formed at the front end of the spiral member 11, and a guide protrusion that slidably engages with the guide groove 8 on the outer surface of the holding portion 15. 16 is formed in the position which faced. That is, the spiral member 11 and the shaft tube 1 are relatively unrotatable but can be moved back and forth.
Moreover, although the slit 17 is formed in the holding part 15 at a position facing it, it may be provided on one side. By providing the slit only on one side, the holding force of the holding member becomes stronger and the holding force does not decrease with time. Protrusions 18 and 19 are formed on the opposed inner surfaces of the slit 17, and these protrusions 18 and 19 are formed in different directions and in the front-rear direction. That is, a protrusion 18 is formed in front of the upper inner surface of the slit 17 located on the right side in FIG. 5, and a protrusion 19 is formed behind the lower inner surface. On the other hand, a protrusion 19 is formed behind the upper inner surface of the slit 17 located on the left side, and a protrusion 18 is formed in front of the lower inner surface. Further, the tops of the protrusions 18 and 19 are located on the central axis H of the slit 17. That is, the gap formed between the tops is 0 mm. The protrusion 18 has a substantially triangular shape, but may have an arc shape.
Furthermore, the holding portion 15 has a circular cylindrical shape, and the width of the slit 17 is about one third of the outer diameter of the holding portion 15, but is not limited thereto. It is not something. A relatively flexible rod-like body 14 such as a colored pencil, a crayon, a lipstick, and an eraser is gripped by the holding portion 15 having a circular diameter. A rod-shaped body may be sufficient. A holding projection for holding the rod-like body 14 is formed on the inner surface of the holding portion 15, but depending on the flexibility of the rod-like body 14, it may be held in a state of being buried in the surface of the rod-like body 14. Become. Alternatively, the rod-like body 14 may be held by applying a satin finish to the inner surface of the holding portion 15 or coating a rubber-like elastic body. The falling off from the holding part 15 during use is reliably prevented.

  Reference numeral 20 denotes a cap that is detachably attached to the rear end of the spiral member 11, and prevents the replacement core 21 housed in the hollow portion 12 of the spiral member 13 from falling off.

  Next, the operation will be described. When the shaft cylinder 1 and the rotating shaft 2 are relatively rotated, the spiral member 11 moves forward. This is because the inner surface protrusion 6 of the rotating shaft 2 is engaged with the male screw portion 13 and the guide protrusion 16 of the spiral member 11 is engaged with the guide groove 8 of the shaft tube 1. The amount of rotation feeding increases as the rod-shaped body 14 is consumed, and eventually the rod-shaped body 14 is almost used. At this time, the rod-like body 14 is replaced. At the most advanced position of the spiral member 11, the slit 17 of the holding portion 15 is expanded by the vertical rib 9 of the shaft cylinder 1, and the use is finished. The rod-like body 14 can be easily extracted from the holding portion 15 and discharged. Here, since the gap formed between the tops of the projections 18 and 19 formed in the slit 17 is 0 mm, at least the thickness of the vertical rib 9 is expanded. Yes.

Next, the assembly operation of the rotating shaft 2 and the spiral member 11 and the rotating shaft 2 and the shaft tube 1 will be described. First, the spiral member 11 is assembled to the rotary shaft 2, but the spiral member 11 may be inserted into the rotary shaft 2, the male screw portion 13 and the female screw portion 6 are engaged, and then screwed to a predetermined position while being rotated. . However, this assembly method takes time. In the present invention, the spiral member 11 can be inserted into a straight line with respect to the rotating shaft 2 at once, and assembled and screwed together. That is, when the helical member 11 is inserted into the rotary shaft 2, the front portion of the reduced diameter portion 2b is expanded by the slit 2c (see FIG. 6), thereby being easily inserted and the male screw portion 13 and The female screw part 6 is screwed together.
Next, the rotating shaft 2 to which the spiral member 11 is screwed is mounted on the shaft tube 1, but when the shaft is mounted, the outward expansion operation of the reduced diameter portion 2 b of the rotating shaft 2 is prevented. That is, the protrusion 2d formed on the outer periphery of the reduced diameter portion 2b comes into contact with the inner peripheral surface of the shaft tube 1, thereby restricting the expansion of the reduced diameter portion 2b. Thereby, the screwing of the female screw 13 and the female screw 6 is ensured, and a good rotation feeding operation can be performed without being released.
In addition, by changing the height of the protrusion 2d formed on the reduced diameter portion 2b, the rotational sliding resistance between the shaft tube 1 and the rotary shaft 2 can be changed as appropriate.

A second example will be described with reference to FIG. It is the example which obstruct | occluded the both sides of the longitudinal direction of the slit of the said 1st example. The same code | symbol is attached | subjected to the structure similar to the said 1st example. By closing both sides of the slit 2g, it is possible to prevent warping of the reduced diameter portion 2b, excessive expansion, and deformation of the cross-sectional shape during molding.
In the above two examples, when the female screw is formed by injection molding or the like, the female screw is expanded by the slit, so that the female screw part is damaged even if the female screw is forcibly removed straight without rotating from the core pin. Can be removed (from the core pin), which can significantly improve productivity.

The longitudinal cross-sectional view which shows a 1st example. The external view of a rotating shaft. The longitudinal cross-sectional view of FIG. The external appearance perspective view of a rotating shaft. The external view of a spiral member. The external view which shows an assembly process. The external view which shows the 2nd example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft cylinder 2 Rotating shaft 2a Protrusion part 2b Reduced diameter part 2c Slit 2d Protrusion 2e Circumferential protrusion 2f Slit 2g Slit 3 Recessed part 4 Convex part 5 Clip 6 Inner protrusion 7 Reduced diameter part 8 Guide groove 9 Vertical rib 10 Arc part 11 Spiral member 12 Hollow part 13 Male thread part 14 Rod-like body 15 Holding part 16 Guide protrusion 17 Slit 18 Projection 19 Projection 20 Cap 21 Replacement core 22 Projection 23 Projection

Claims (4)

A screwed structure of a male screw and a female screw, wherein a slit is formed in the female screw. The threaded structure according to claim 1, wherein a slit is formed on the circumference of a region of the female thread portion of the female screw. The screwing structure according to claim 1 or 2, wherein a guide tube is coated on an outer periphery of the female screw. The screw structure according to claim 3, wherein the female screw and the guide tube are relatively rotatable.

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