JPS6137847Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention consists of a female member and a male member, and after inserting the legs of the female member into a through hole bored through the stacked panels, the male member is inserted into the insertion hole provided in the female member. By press-fitting the shaft part of the synthetic resin fastener, the leg expands inside the through hole, and the expanding leg can fix the stacked panels together with the collar provided on the female member. A projection is provided on the inner circumferential surface of the insertion hole of the female member, and a threaded portion is formed on the circumferential surface of the shaft portion of the male member, and when the press-fitting is performed, the male member is allowed to pass over the projection, and when the fixation is released, the male member This invention relates to an improved method of a fastener that can be unscrewed by twisting the screw to guide the threaded part to the protrusion.

Fasteners that use a combination of male and female members to secure together stacked panels are already known, and many proposals have been made. The present invention is a type in which the leg of the female member is inserted into the through hole of the panel, and then the shaft of the male member is press-fitted into the insertion hole provided in the female member, thereby expanding the leg end and exerting the fixing function. The present invention provides an improvement to the fastener in which the panel can be released from the fixed state by twisting the press-fitted male member to allow the shaft portion to be pulled out from the insertion hole.

A fastener in which the shaft portion can be removed from the insertion hole by twisting the male member has already been disclosed by the applicant in JP-A-56-10811.
The fastener proposed here has a protrusion on the upper inner circumferential surface of the insertion hole, and when the shaft of the male member is press-fitted, the threaded part formed on the circumferential surface is used to push the above protrusion using the flexibility and slippage of the material. This allows press-fitting to be carried out by overcoming the pressure-fitting part, and at the same time, when the protrusion is pulled out after press-fitting, it is possible to unscrew it by engaging the protrusion with the threaded part.

One difficulty with this previously proposed fastener is that forming a protrusion with a high engagement force on the inner peripheral surface of the insertion hole of the female member is restricted from the viewpoint of molding technology.

The present invention was devised in view of this point, and by providing the above-mentioned protrusion directly above the slit cut into the leg of the female member from the leg end, it is easy to press-fit the shaft of the male member. It is an object of the present invention to provide an improved fastener that has a high engagement force after press-fitting and also allows easy molding of the protrusion.

Hereinafter, this invention will be explained with reference to the illustrated embodiments, and its features will be explained in detail.

Fig. 1 is a partially cross-sectional front view of the fastener of the present invention, and Fig. 2 is a front view of the right half of the female and male members separated, with the reference numeral 1 indicating the female member. 2 indicates a male member.

The female member 1 includes a tsuba 3 and legs 4 hanging from the bottom of the tsuba.
The male member 2 is formed from a head 5 and a shaft 6 extending vertically from the head.

The collar 3 of the female member is in the shape of a disk, and a leg 4 is suspended from the center of the lower surface, and the leg 4 is approximately cylindrical and the peripheral surface of the leg end is reduced in diameter to form a tapered surface. It has been done. The female member 1 equipped with this collar and legs has a perfect circular insertion hole 7 with a depth reaching from the center of the upper surface of the collar 3 to the center of the leg 4, and the leg 4 has a cross-shaped insertion hole 7 extending from the end of the leg. The script body is divided into four pieces by cutting a slit 8, and a protrusion 9 is provided on the inner circumferential surface of the insertion hole 7 to project inward from a portion directly above the slit 8.

The insertion hole 7 is for receiving the shaft portion 6 of the male member 2, and is a perfect circular hole with the same diameter from the opening 10 on the upper surface of the collar 3 to the middle of the length, reaching the center of the leg 4. The lower end, ie, the bottom 11 of the hole, is formed into a tapered surface with a tapered diameter. Each slit 8 cut from the leg end is cut to just below the collar 3 so that its upper end reaches the perfect circular hole part of the fitting hole 7, and a projection 9 is provided at the part directly above the upper end. It is designed so that it can be used.

The protrusion 9 is for engaging a threaded portion formed on the circumferential surface of the shaft portion of the male member 2, as will be described later, and has an upper surface as an inclined surface and a lower surface as a horizontal surface, as shown in an enlarged view in FIG. It is formed in the shape of a non-return claw, and its horizontal lower surface is aligned with the upper end surface of the slit 8.

On the other hand, the male member 2 has a shaft 6 that is vertically disposed from the lower surface of the head 5 and is formed into a rod-shaped shaft with a perfect circular cross section approximately equal to the diameter of the insertion hole 7, and its length is longer than the depth of the insertion hole 7. The tip end portion 12 of the shaft is tapered to a conical shape. A threaded portion 13 is formed on the peripheral surface of the perfectly circular shaft portion, and a cross-shaped engagement groove 14 for engaging a tool such as a screwdriver is provided in the center of the upper surface of the head 5, so that the entire male member is screwed. It is shaped like this.

The fastener of the present invention consists of the above-mentioned female and male members, and these two members are individually molded from a synthetic resin having appropriate elasticity and rigidity, such as nylon resin.

FIG. 5 shows the state in which two panels A and B are fixed together using the fastener of the present invention, and both panels A and B have a through-hole through which the leg 4 of the female member 1 is inserted. After forming holes a and b in advance and overlapping them, first insert the legs 4 of the female member into the through holes a and b from one panel A side and attach the flange 3.
is brought into contact with the surface of panel A. After that, the shaft portion 6 of the male member 2 is inserted into the insertion hole 7 of the female member, and the threaded portion 13 on the peripheral surface of the shaft portion 6 is inserted into the projection 9 on the inner peripheral surface of the insertion hole.
While pushing and dipping the tip part 12 into the bottom part 1 of the insertion hole.
1, and then press the head 5 further to make it penetrate straightly, and push open the bottom 11, which forms a tapered surface at the tip 12, and insert the tip of the leg 4, which is divided by the slit 8, into the panel. Panel A expanded on the B side and overlapped by the expansion of the tsuba 3 and this leg,
It fixes B.

During this fixing, the male member 2 inserts the shaft portion 6 into the insertion hole 7.
When inserted into the slit, the threaded part 13 formed on the circumferential surface abuts against the protrusion 9, but the material of this threaded part and the protrusion has elasticity and slippage, and the protrusion also fits into the slit 8.
Since it is located directly above the slit and its lower surface coincides with the upper end surface of the slit and can be freely bent toward the slit side, it provides considerable resistance to intrusion from the opening 10 side of the insertion hole. This allows the threaded portion 13 to pass through without any damage, and the protrusion 9 is not scraped or irreparably immersed during this passage. Therefore, insertion of the shaft portion 6 is relatively easy, but after the insertion is completed, the protrusion 9 returns to its original shape and engages in the trough of the threaded portion 13.
Since this protrusion has a non-return claw shape, it reliably engages with the crest of the screw and prevents the shaft from moving in the pulling direction. In particular, as mentioned above, this protrusion is flexible, so when the male member receives a force in the pulling direction, it follows the thread and comes into close contact with it, preventing the thread from moving, which is the complete opposite of what happens when press-fitting. I will do it.

In this manner, the fastener of the present invention allows the shaft portion 6 to be easily inserted into the insertion hole 7 when securing the panel. On the other hand, since the engagement between the threaded portion 13 and the protrusion 9 after insertion becomes reliable, a stable fixed state can be obtained.

Of course, the shaft portion 6 inserted into the insertion hole has a threaded portion 13.
Needless to say, since the protrusion 9 is to be engaged with the valley of the head 5, it can be easily pulled back by hooking a tool such as a screwdriver into the engagement groove 14 of the head 5 and twisting it, so that the panel can be unfixed. stomach.

As described above, especially in the present invention, by forming the protrusion 9 on the inner circumferential surface of the insertion hole 7 directly above the slit 8, the protrusion 9 is bent toward the slit when the shaft portion 6 is inserted, making it easy to pass through. This makes it easy to insert the shaft, and since sufficient deflection can be expected, the height of the protrusion can be increased to increase the engagement force upon completion of insertion.

Furthermore, when manufacturing this kind of fastener, it is generally customary to integrally mold it by injection molding, but in this case, in the case of the female member, a protrusion 9 is formed on the inner peripheral surface of the insertion hole 7 The selection of molding molds has become complicated,
Although it is difficult to form the protrusion 9 with sufficient height, in the present invention, the protrusion is provided directly above the slit, and the lower surface of the protrusion matches the upper end surface of the slit. This protrusion can be easily formed by a combination of a punching die and a punching die laterally along the slit, which is also advantageous in terms of manufacturing.

In carrying out the present invention, the cutting depth from the leg end of the slit 8 that divides the leg 4 is made different between adjacent slits, and thereby the position of the protrusion 9 provided directly above each of the slits 8 is made different. If the protrusions 9 are shifted and arranged along the threaded pattern, that is, if they are arranged in an inclined manner to match the pitch of the threaded part 13 formed on the shaft part 6 (see FIG. 3), all the protrusions 9 will engage with the threaded part. (4 in this embodiment), the shaft portion 6 is stably inserted, and at the same time, the guidance when unscrewing becomes smooth, so that the fixation can be quickly released.

[Brief explanation of the drawing]

The drawings show one embodiment of the fastener of the present invention; Fig. 1 is a partially sectional front view, Fig. 2 is an exploded front view with the right half sectioned, and Fig. 3 shows the main parts. FIG. 4 is a sectional view taken along the line of FIG. 2, and FIG. 5 is a partially sectional front view showing the state of use. 1 is a female member, 2 is a male member, 3 is a tsuba, 4 is a leg, 5
is the head, 6 is the shaft, 7 is the insertion hole, 8 is the slit,
9 is a protrusion, and 13 is a male screw.

Claims (1)

[Scope of utility model registration request] A leg hanging from the bottom of the tsuba, a perfect circular insertion hole cut vertically from the top of the tsuba along the center of the leg, and a slit cut vertically from the bottom of the leg to divide the leg into multiple pieces. and a male member with a head and a shaft with a perfect circular cross section that hangs down from the lower surface of the head, and is made of a female member with a head and a shaft with a perfect circular cross section. insert the leg of the female member into the female member, and then expand the leg by press-fitting the shaft portion of the male member into the insertion hole of the female member, and separate the panel overlapped by the expanded portion and the collar. In synthetic resin fasteners that can be firmly fixed,
A protrusion is provided on the inner circumferential surface of the insertion hole of the female member to protrude inward from just above the slit, and a threaded portion is formed on the circumferential surface of the shaft portion of the male member, so that this protrusion is provided during the press-fitting. It climbs over to allow the shaft to be press-fitted, and when press-fitting is completed, it engages with the valley of the screw to maintain the fitted state, while when releasing the panel, twist the head of the male member to guide the protrusion. A fastener characterized by being able to unscrew its shaft portion.