JP2001239547A - Double molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strongly and closely bond a base stand corresponding to a main body part and a coating layer having an anti-slip function or the like in a double molded object suitable as the grip of a tool or the like. SOLUTION: In the double molded object consisting of the base stand and the coating layer covering the periphery of the base stand at least partially by insert molding, the base stand is rotated at a time of insert molding and a connection means for strongly and closely bonding the coating layer to the periphery of the base stand is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double molded body comprising a base and a coating layer at least partially surrounding the base, which are intended to firmly adhere to each other, As such a double molded body, for example, it can be applied to various kinds of tools such as a saw handle or a hammer grip including a cutter grip and a folding type, a tool such as a tape measure case, and a golf club and a bat grip. In the following, a description will be given by taking a grip of a cutter knife as an example.

[0002]

2. Description of the Related Art A grip of a cutter knife is usually a base having a groove-shaped cross-section formed by injection molding of a thermoplastic resin such as polypropylene. A metal sheath that holds the blade slidably is attached.

[0003] In such a base, a coating layer made of an elastomer (synthetic rubber or the like) is disposed over the entire surface or locally from the viewpoint of preventing slippage when using a cutter knife, easiness of gripping, or design. It is becoming.

[0004] In this elastomer coating layer, a base preformed by injection molding or the like is inserted and arranged in a mold different from a mold for molding the base, and an elastomer layer is formed therearound. , So-called insert molding.

[0005] Usually, the coating layer is brought into close contact with the base by heat welding at the time of forming the coating layer. By adopting such a method, a drastic improvement in design can be achieved, and The grip and the anti-slip effect during use have been enhanced, and significant improvements have been made in terms of function. As a literature on this point, reference is made to JP-A-61-213145 relating to a composite plastic molded product.

[0006]

By the way, it is necessary to use a material having high rigidity for the base to secure the strength, while a relatively soft material is used for the coating layer in order to improve the anti-slip effect and the like. Since it is necessary to use them, they are usually made of different materials, and in order to ensure high adhesion between them, the materials to be used are limited. In the case of a grip to be provided, for example, the coating layer may be separated from the edge portion of the device over a long period of use, or may be separated by an impact such as dropping,
The solution is desired.

[0007] An object of the present invention is to propose a novel double molded article that can firmly adhere a base and a coating layer regardless of the material used, regardless of the presence or absence of an impact. Where you do it.

[0008]

According to the present invention, there is provided a double molded body comprising a base and a coating layer which at least partially covers the periphery of the base by insert molding. It is a double molded body characterized by having a connecting means for wrapping around and firmly adhering the coating layer around the base.

In the double molded body having the above-described structure, the connecting means includes a plurality of through-holes penetrating the base, and an opening or a slit which is opened at least locally on the surface of the base at each of these through-holes. It is desirable to do.

[0010] Further, the connecting means may be a plurality of concave portions or convex portions having a divergent shape such that the cross-sectional area increases toward the distal end.

The base is preferably made of a resin such as ABS (acrylonitrile-phthalene-styrene) or polypropylene, and the coating layer is preferably made of a styrene-based or olefin-based elastomer.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below more specifically with reference to the drawings. 1 to 3 show an example in which the double molded body of the present invention is applied to a grip of a cutter knife.

In FIG. 1, reference numeral 1 denotes a base having a groove-shaped cross section. In the groove-shaped cross section of the base 1, although not shown, a sheath for slidably holding a blade of a cutter is arranged. Reference numeral 2 denotes a coating layer that at least partially covers the periphery of the base 1. The coating layer 2 has a plurality of anti-slip grooves 2a formed on its surface as shown in FIG. It itself has an anti-slip function and is made of an elastomer such as synthetic rubber, which can improve the ease of gripping.

FIGS. 4 and 5 are views showing only the base 1 in the grip of the cutter knife shown in FIG. 1 above.

The base 1 according to the present invention has a plurality of through-holes 3 penetrating the main body thereof, and a slit provided at each of the through-holes 3 so as to open at least locally on the surface of the base 1. The connecting means shown in the example provided with 4 is provided.

In order to bring the coating layer 2 into close contact with the base 1,
As shown in FIG. 4 (b), although it is possible by simply providing a through-hole 5 in the base 1 and passing an elastomer which will become the coating layer 2 at the time of insert molding through the through-hole 5, in this kind of grip, Since the size of the through-hole is also limited, it may not be possible to ensure a smooth flow of the elastomer. As for the heat sealability, ABS resin and styrene-based elastomer or P
The best combination of P and olefin elastomer is
In the combination of ABS + styrene, the elastomer is expensive and the molding conditions are extremely strict (the molding conditions are narrow). On the other hand, in the case of the combination of PP + olefin elastomer, the price of the elastomer is not so high, Conditions are extremely severe.

In the present invention, a slit 4 communicating with the surface of the base 1 is provided in the through hole 3.
According to such connecting means, as shown in FIG. 6, the elastomer can be passed through the slit 4 even if the size of the through hole 3 is limited as shown in FIG. The base 1 and the coating layer 2 are firmly adhered to each other even if the base 1 and the coating layer 2 cannot be expected to be so closely bonded by thermal welding.

In such a connecting means, as shown in FIG. 7, a plurality of openings 6 having a diameter enough to allow the elastomer to enter may be provided along the through holes 3 instead of the slits 4.

FIGS. 8 (a) and 8 (b) show another example of the configuration of the double molded body according to the present invention, with respect to the principal part thereof. In FIG. 4 described above, the cross-sectional shape of the through-hole 3 is shown as being circular, but this may be triangular (trapezoidal) or rectangular, and the cross-sectional shape is not particularly limited.

FIGS. 9 (a) to 9 (c) show other structural examples of the double molded body according to the present invention, with respect to the cross section of the main part.

FIG. 9 shows a convex portion 7 having a cross-sectional area increasing toward the front end of the surface of the base 1.
In this case, the coating layer 2 is firmly adhered to the base 1 also in this case.

The projections 7 may be continuous as shown in FIG. 10 or may be locally arranged as shown in FIG.

9 to 11 show an example in which the convex portion 7 is formed on the surface of the base 1. If there is no particular problem in molding the base 1, it is not shown but is similar to the convex portion. May be formed.

12 (a) and 12 (b), the through hole 3 as shown in FIG. 4, FIG. 7 or FIG. 8, and the projection 7 as shown in FIG. 9 to FIG. 11 cannot be provided. A concave portion 8 is provided at a location, particularly at the edge of the grip, and the elastomer is wrapped around the concave portion 8. By providing such a concave portion 8, the base 1 and the coating layer 2 can be firmly connected. .

FIG. 4 shows a case where the through holes 3 and the slits 4 are formed in an array perpendicular to the longitudinal direction of the base 1 and in parallel with each other.
As shown in FIGS. 3 (a) and 3 (b), a C-shaped arrangement may be used, or an arrangement may be made so as to have a certain angle with respect to the longitudinal direction of the base 1. In this regard, in particular, There is no limitation.

Although the present invention has been described with reference to an example having a groove-shaped cross section, such as a grip of a cutter, a coating layer is formed on the entire area of the base, for example, a grip of a hammer or a golf club or a grip of a handle of a bicycle. In particular, the present invention can be advantageously applied to a case in which the coating layer slips on the base and causes an inconvenience.

FIG. 14 shows an example in which a coating layer 10 is provided on the outer surface of a tape measure case 9 as a base. Such a tape measure has a high anti-slip effect, and the covering layer 10 functions as a protective layer even if it is accidentally dropped during operation, so that the tape measure case 9 is not easily damaged, and has a long service life. Becomes possible.

FIG. 15 shows an example in which the double molded body according to the present invention is applied to a folding saw, and FIG. 16 shows an example in which it is applied to a hammer.

If there is a concern that the rigidity of the base 1 is reduced by providing the slits 4 as shown in FIG. 4 above, measures such as increasing the thickness of the coating layer 2 at the site are taken. This can be easily dealt with.

[0030]

According to the present invention, the adhesion between the base and the coating layer can be remarkably enhanced, and a desired function can be stably exhibited for a long period of time even under a severe use environment for a long period of time. In addition, since the coating layer can be provided on the base in a spot-like manner, it is possible to reduce the manufacturing cost by using only the minimum necessary amount and to save resources.

[Brief description of the drawings]

1 (a) to 1 (c) show an example in which a double molded body according to the present invention is applied to a grip of a cutter.

FIG. 2 is a view showing a back surface of the grip shown in FIG. 1;

3 (a) is a view along AA in FIG. 1, and FIG. 3 (b) is a view along BB in FIG.

FIGS. 4A to 4C are views showing the base of FIG.

FIG. 5 is a view showing a rear surface of the base shown in FIG. 4;

FIG. 6 is a view showing a cross section taken along line CC of FIG. 1;

FIG. 7 is a view showing another configuration example of the double molded article according to the present invention.

FIGS. 8 (a) and (b) are diagrams showing another configuration example of the double molded article according to the present invention.

FIGS. 9 (a) to 9 (c) are diagrams showing another configuration example of the double molded article according to the present invention.

FIG. 10 is a view showing another configuration example of the double molded body according to the present invention.

FIG. 11 is a view showing another configuration example of the double molded article according to the present invention.

FIGS. 12A and 12B are diagrams showing a configuration example for bringing a base and a coating layer into close contact with each other at an edge of the base.

FIGS. 13 (a) and 13 (b) are diagrams showing another configuration example of the double molded article according to the present invention.

FIG. 14 is a diagram showing an example in which the present invention is applied to a tape measure case.

FIG. 15 is a diagram showing an example in which the present invention is applied to a folding saw.

FIG. 16 is a diagram showing an example in which the present invention is applied to a hammer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 base 2 coating layer 3 through hole 4 slit 5 through hole 6 opening 7 convex portion 8 concave portion 9 case 11 coating layer

Claims (4)

[Claims] 1. A double molded body comprising a base and a coating layer that at least partially covers the periphery of the base by insert molding, wherein the base is wrapped around during insert molding, and the coating layer is attached to the base. A double molded body having a connection means for firmly adhering around the periphery. 2. The connecting means comprises a plurality of through-holes penetrating the base, and an opening or slit for opening at least locally on the surface of the base at each of these through-holes.
The double molded product according to claim 1. 3. The double molded body according to claim 1, wherein the connecting means is a plurality of concave portions or convex portions that expand toward the front. 4. The base according to claim 1, wherein the base is made of a resin such as ABS or polypropylene, and the coating layer is made of an elastomer such as styrene or olefin.
The double molded article according to any one of the above.