Background of the Invention It has been known that in an article such as a vehicle seat, a home chair or a mattress comprising a cushioning core member molded, for example, from foamable resin and a soft surface member covering the surface of the core member such as a fabric or a leather, an interengaging fastener (a so-called surface fastener) provided with a plurality of engaging elements on one or major surface of a base is used for affixing the surface member to the core member. Particularly, since it is desired to provide comfort of a high level to the user in a case or the seat or the chair, a flexible strip-like fastener is often used for bonding the surface member to the core member, which is capable of being arranged within an elongate groove formed on the surface of the core member along a seam or others of the surface member (see, e. g. , Japanese Unexamined Patent Publication (Kokai) No. 11-127915). In such an aspect, the strip-like fastener is integrally bonded at its base to the core member, while the engaging elements thereof are detachably engaged with mating objectives provided in the surface member, such as fiber loops.

To secure the strip-like fastener of such a type at a desired position on the surface of the core member with the engaging elements thereof being exposed outside, an insert- molding method for fixing the fastener to the core member simultaneously with the molding of the core member is advantageously applicable, wherein the fastener is disposed as an insert within a mold for the core member which is a main body to be molded. In this insert molding method, a rail-shaped elongate guide is arranged within the mold for the main body to be molded, for holding the strip-like fastener at a predetermined position (see, e. g. , Japanese Unexamined Patent Publication (Kokai) No. 2000-317945). The guide has an elongate groove capable of accommodating the base and the engaging elements of the strip-like fastener, and the fastener is installed in the guide while inserting the engaging elements and the base thereof into the groove and a back surface of the base is exposed outside from the groove.

A typical guide in the prior art has a bottom wall and a pair of side walls protruded from the bottom wall, by which is defined an elongate groove for accommodating the strip-like fastener. At each of longitudinal opposite ends of the groove, a seal is provided for preventing a liquidized material from entering the groove when the main body is molded. The strip-like fastener is held in the groove while inserting the engaging elements into the interior of the groove defined between the side walls and the seals and bringing a surface area of the base in tight contact with the corresponding surface area of the side walls and the seals. Under the condition, the liquidized material is poured into the cavity in the mold to mold the main body, whereby the strip-like fastener is fixedly secured at a predetermined position on the surface of the main body thus molded.

Summary of the Invention According to the prior art strip-like fastener described above, it is necessary not only to ensure a predetermined level of a bonding force derived from the engaging elements with the mating objectives but also to sufficiently guarantee the attachment strength of the base to the molded main body. Especially, in an aspect wherein the strip- like fastener is used as means for bonding the surface member to the core member of a vehicle seat or a chair described above in which a tension is intermittently applied to the surface member due to the frequent and sudden movement of the center of gravity of a seated user or the surface member is intentionally peeled from the core member for the purpose of the replacement of the former, it is required that the attachment strength of the base is larger than the bonding force derived from the engaging elements to prevent the interconnection between the fastener and the core member from breaking.

From such a viewpoint, the prior art strip-like fastener described above is provided, on the back surface of the base (opposite to the major surface), with portions to be fixedly embedded into the molded main body via the insert-molding process. According to this structure, the main body is molded to encircle the portions projected from the back surface of the base, whereby the embedded portions are secured into the molded main body and the strip-like fastener is fixedly coupled thereto. If one wishes to increase the attachment strength of the fastener to the molded main body, however, it is necessary to secure a sufficient surface area in the embedded portion projected out from the base. As a result, there may be a risk in that the material cost of the strip-like fastener rises or a mold for the fastener becomes complicated to increase the production cost thereof.

Accordingly, an object of the present invention is to provide a guide for integrally attaching a strip member to a molded main body, capable of improving the attachment strength of the strip member to the molded main body as much as possible without rising the production cost of the strip member.

In one aspect, the invention defined in claim 1 provides a guide comprising a bottom wall, a pair of side walls projecting upright from the bottom wall and an elongated groove defined by the bottom wall and the pair of side walls, the guide being capable of detachably accommodating a strip member in the groove. At least one of the pair of side walls includes at least one indentation for locally opening the groove to a lateral outside of the guide.

The invention defined in claim 2 provides a guide as defined by claim 1, wherein the indentation is formed respectively in both of the pair of side walls, indentations in both side walls being located at positions corresponding to each other in a transverse direction of the groove.

The invention defined in claim 3 provides a guide as defined by claim 1 or 2, for supporting the strip member including a strip-shaped base and a plurality of engaging elements formed on a surface of the base; wherein the groove includes a first outer section for accommodating the base of the strip member and a second inner section for accommodating the engaging elements of the strip member; and wherein the indentation locally opens the first section to a lateral outside of the guide.

The invention defined in claim 4 provides a guide as defined by claim 3, wherein the base of the strip member includes a plurality of cavities arranged at generally regular intervals in a longitudinal direction; and wherein the indentation is formed at a position capable being aligned with at least one of the cavities in the base accommodated in the first section of the groove.

The invention defined in claim 5 provides a guide as defined by claim 4, wherein a plurality of indentations are arranged in a longitudinal direction of the groove at intervals substantially identical to those of the cavities in the strip member.

The invention defined in claim 6 provides a guide as defined by claim 5, further comprising a positioning pin for holding the strip member at a position in which the cavities are aligned respectively with the indentations.

Brief Description of the Drawings Fig. 1 (a) is a plan view of a guide according to one embodiment of the present invention; and Fig. l (b) a side view thereof.

Fig. 2 is a plan view of a typical fastener to which the guide shown in Fig. 1 is applicable, as seen from a major surface side.

Fig. 3 (a) is a plan view of the fastener shown in Fig. 2 as seen from the major surface side; Fig. 3 (b) a side view thereof ; and Fig. 3 (c) a plan view thereof as seen from a back surface side; all of which are shown in an enlarged scale.

Fig. 4 (a) is a plan view of the guide shown in Fig. 1 to which the fastener shown in Fig. 2 is attached; and Fig. 4 (b) a side view thereof.

Fig. 5 (a) is a sectional view of the guide and the fastener shown in Fig. 4 taken along a line A-A; and Fig. 5 (b) an enlarged view of a portion indicated by an arrow B.

Fig. 6 is a schematic perspective view of a vehicle seat to which the present invention is applicable.

Fig. 7 is an enlarged sectional view showing a fastener attachment portion in the vehicle seat of Fig. 6 manufactured by using the guide shown in Fig. 1.

Detailed Description of the Invention The preferred embodiments will be described below with reference to the attached drawings, in which common reference numerals are used for denoting the corresponding constituent elements throughout the drawings.

Fig. 1 shows one embodiment of a guide 10 according to the present invention.

Figs. 2 and 3 show a strip-like fastener 12 (hereinafter merely referred to as a fastener 12) as a typical strip member to be supported by the guide 10. The fastener 12 is a face-to- face engagement type fastener which is flexible to conform with a three-dimensional surface of the molded main body, and as described later, is provided with a strip-shaped base 14 and a plurality of engaging elements 18 projected from a major surface 16 of the base 14 at a predetermined pitch. In this regard, the guide according to the present invention is applicable not only to the illustrated fastener 12 but also to various strip-like fasteners of other types.

The guide 10 is a linear rail-like block for supporting the fastener 12 over a predetermined length, having a pair of side walls 22 projected integrally with a bottom wall 20 along opposite edges thereof extending in the longitudinal direction of the bottom wall 20. The bottom wall 20 and the pair of side walls 22 define one elongate groove 24 throughout a total length of the guide 10, which is capable of accommodating the base 14 and the engaging elements 18 of the fastener 12 in an extended state (that is, a state in which the fastener is not wound or folded itself).

The bottom wall 20 of the guide 10 has a generally flat rectangular outer surface 20a, a pair of sealing surfaces 20b, 20c provided in the respective longitudinal end regions on a side opposite to the outer surface 20a to extend between the opposite side walls 22, a pair of auxiliary supporting surfaces 20d provided adjacent to the respective side walls 22 to extend generally in parallel to the outer surface 20a in the longitudinal direction, and a groove bottom surface 20e provided in a region defined inside the sealing surfaces 20b, 20c and the auxiliary supporting surfaces 20d to extend in the longitudinal direction of the guide 10 at a position further closer to the outer surface 20a. The pair of side walls 22 have generally flat inner surfaces 22a, respectively, disposed opposite to each other while spaced at a uniform distance all over a total length of the guide 10. The inner surface 22a of the side wall 22 extends generally vertical to the sealing surfaces 20b, 20c and the auxiliary supporting surfaces 20d.

One of the sealing surfaces 20b of the bottom wall 20 extends generally in parallel to the outer surface 20a to be connected to the pair of auxiliary supporting surfaces 20d in a stepless manner. The other of the sealing surfaces 22c of the bottom wall 20 is connected to the pair of auxiliary supporting surfaces 20d in a stepless manner while extending along a concave curvilinear line from a boundary of the auxiliary supporting surface 20d to a longitudinal distal end of the bottom wall 20 to be gradually away from the outer surface 20a. The groove 24 is defined above the sealing surfaces 20b, 20c and the auxiliary supporting surfaces 20d between the inner surfaces 22a of the side walls 22, and functionally divided into a first outer section 24a defined above the sealing surfaces 20b, 20c and the auxiliary supporting surfaces 20d between the inner surfaces 22a of the side walls 22 to be capable of accommodating the base 14 of the fastener 12, and a second inner section 24b defined beneath the sealing surfaces 20b, 20c and the auxiliary supporting surface 20d and above the groove bottom surface 20e to be capable of accommodating the engaging elements 18 of the fastener 12.

A distance between the inner surfaces 22a of the side walls 22 (that is, a cross- sectional dimension of the first section 24a of the groove 24) is approximately equal to the widthwise dimension of the base 14 of the fastener 12 to be supported. Accordingly, when the fastener 12 is properly accommodated in the groove 24 of the guide 10, the inner surface 22a of the respective side wall 22 is substantially in tight contact with a lateral edge of the base 14 of the fastener 12 accommodated within the first section 24a of the groove 24 and extending in the longitudinal direction. Also, the pair of sealing surfaces 20b, 20c of the bottom wall 20 are substantially in tight contact with the major surface 16 in the vicinity of the longitudinal opposite ends of the base 14 of the fastener 12. In such a manner, the guide 10 accommodates the engaging elements 18 of the fastener 12 within the second section 24b of the groove 24 while engaging the base 14 within the first section 24a of the groove 24 so that the fastener 12 is maintained at a predetermined position due to a frictional force. As a result, when the main body is molded while supporting the fastener 12 in the guide 10, a liquidized material is prevented from entering the second section 24b of the groove 24.

The present invention is characterized in that the guide 10 has a plurality of indentations 26 formed on both of the side walls 22. The indentations 26 have generally identical size and shape to each other and are arranged at a generally equal pitch in the longitudinal direction of the groove 24 on the side walls 22 so that the corresponding two of them positioned on the respective side walls are opposed to each other on a line transverse to the groove 24. The respective indentation 26 is a generally rectangular vacant space in the side wall 22 defined between the upper edge of the respective side wall 22 to a line located slightly above the lower edge thereof (that is, the auxiliary supporting surface 20d of the bottom wall 20). Accordingly, the respective indentation 26 operates at its position to locally open the first section 24a of the groove 24 laterally to the guide.

Although the guide 10 of the above-mentioned structure has been described that it has substantially a linear configuration, the guide should not be limited thereto but may have a three-dimensionally curved configuration so that when fixed, for example, to the core member of the vehicle seat, the fastener 12 can be installed along a three- dimensionally curved seam of the surface member covering the core member. Also, in this case, it is possible to form the above-mentioned plurality of indentations 26 on both of the side walls 22 according to the predetermined arrangement. In this regard, the guide 10 may be formed as a one-piece body from a metallic rod of aluminum, aluminum alloy, steel or others through a cutting process, etc.

A typical strip member to be accommodated within the guide 10; i. e. , the fastener 12; has a strip-shaped base 14 including a plurality of box sections 28 spaced at a pitch in the longitudinal direction and a plurality of joints 30 for interconnecting the box sections 28. Each of the box sections 28 is of substantially a hollow structure including flat upper and lower plates 32 and 34 extending generally in parallel to each other, a pair of side plates 36 for connecting the upper and lower plates 32 and 34 to each other, and a partitioning plate 38 extending in the longitudinal direction between these plates 32,34 and 36. The partitioning plate 38 is disposed along a center line 14a extending in the longitudinal direction of the base 14 so that a pair of cavities 40 are defined in symmetry with each other relative to the center line 14a of the base. Thus, a plurality of cavities 40 are symmetrically arranged relative to the center line 14a all over the length of the base 14 at a generally equal pitch.

The major surface 16 of the base 14 is defined by the upper plates 32 of the box sections 28. Also, a back surface 42 of the base 14 disposed opposite to the major surface 16 is formed by the cooperation of the lower plates 34 of the box sections 28 and the joints 30. Each of the engaging elements 18 includes a stem 44 projecting generally upright from the upper plate 32 of the respective box section 28 and a plurality of engagement pieces 46 protruding laterally from a distal end portion of the stem 44 to be detachably engageable with engaging elements of a mating member corresponding thereto.

In this regard, the box sections 28'positioned at the longitudinally opposite ends have no engaging elements 18.

A slit 48 extending in the crosswise direction is formed in the lower plate 34 of the respective box section 28, generally at a longitudinal center thereof. Further, in the lower plates 34, a rib 50 extends on the back surface 42 in the longitudinal direction along the center line 14a throughout the base 14 while being across the slits 48. In the rib 50, two thin-wall posts 52 per one box section 28 extend along the rib 50 while being projected upright relative to the back surface 42. At a distal end of the respective post 52, a thin- wall anchor 54 extends generally in parallel to the back surface 42. These posts 52 and anchors 54 operate as means to be embedded in the molded main body for the purpose of fixedly attaching the fastener 12 to the molded main body via the insert-molding process described later.

The fastener 12 of such a structure is relatively easily flexible as a whole in the <BR> <BR> horizontal direction, i. e. , that generally in parallel to the major surface 16 and the back surface 42 due to the stress-dispersing action in the respective box section 28 of a hollow structure. Also, due to the hinge action of the thin-wall joint 30, this fastener 12 is <BR> <BR> relatively easily flexible as a whole in the vertical direction, i. e. , that generally vertical to the major surface 16 and the back surface 42. In such a manner, since the base 14 of the fastener 12 is easily flexible both in the horizontal and vertical directions, it is possible to install the fastener at a desired position on a surface of an objective having various three- dimensional shapes while three-dimensionally accurately conforming the base 14 therewith. In this respect, the fastener is preferably formed as a one-piece body from resinous material such as nylon or polypropylene.

In correspondence to the fastener 12 of the above-mentioned structure, the guide 10 has the indentations 16 arranged in the respective side wall 22 along the longitudinal direction of the groove 24 substantially at the same pitch as that of the cavities 40 in the fastener base 14. Accordingly, when the fastener 12 is properly accommodated in the groove 24 of the guide 10 as described before, the cavities 40 in the fastener base 14 are arranged, respectively, at positions in alignment with the indentations 26 formed in the side walls 22 as shown in Figs. 4 and 5. Thereby, the cavities 40 in the fastener base 14 laterally open outside via the indentations 26 in the side walls 22. In this state, an area containing the joint 30 between the adjacent box sections 28 in the fastener base 14 and the opposite side plates 36 is disposed at a position in alignment with a wall section 22b remaining in a region between the adjacent indentations 26 in the respective side wall 22 of the guide 10. Thereby, a gap S (Fig. 5 (b)) between the box sections 28 in the fastener base 14 is closed in a liquid-tight manner by the wall sections 22b.

To enable the fastener 12 to be properly accommodated in the groove 24 of the guide 10 as described above, the guide 10 further includes a positioning pin 56 standing upright from the sealing surface 20b. The positioning pin 56 holds the fastener 12 at the above-mentioned proper position at which the cavities 40 are in alignment with the indentations 26 by engaging with the base 14 of the fastener 12 when the fastener 12 is mounted to the guide 10. In this regard, the fastener 12 has hooks 58 extending outward from the box sections 28'at longitudinal opposite ends of the base 14, respectively. These hooks 58 are of a point symmetrical shape relative to a center of the fastener 12 so that the fastener 12 could be located at the proper position if either one of the hooks 58 is engaged with the positioning pin 56 of the guide 10.

Fig. 6 illustrates an article 62 to which the fastener 12 is integrally attached to the main body 60 to be molded while using the guide 10 of the above-mentioned structure through an insert-molding process. In the embodiment illustrated, the article 62 is a vehicle seat and the molded main body 60 is a core member formed of a foamable resinous material such as polyurethane or others. According to this structure, a plurality of fasteners 12 are used for fixing a surface member 64 of fabric or leather to the molded main body 60. Each of the fasteners 12 is fixedly located in an elongate recess 66 formed on the surface of the molded main body 60 along a desired seam 64a of the surface member 64.

In the insert-molding process, a plurality of guides 10 in correspondence to the fasteners 12 to be attached to the article 62 are placed, in accordance with the arrangement of the fasteners 12 on the surface of the main body 60, within a mold (not shown) for the main body 60 to be molded. The respective guide 10 is secured to the molding surface of the mold with putty, bolts or magnets while directing the groove 24 thereof to the gap of the mold. The respective fastener 12 is installed in the corresponding guide 10 while inserting the engaging elements 18 into the second section 24b of the groove 24 in the guide 10 and engaging the box sections 28 of the base 14 into the first section 24a of the groove 24 in the guide 10. At that time, the cavities 40 provided in the base 14 of the fastener 12 are disposed in alignment with the indentations 26 provided in the side walls 22 of the guide, as described before. Also, portions to be embedded (the posts 52 and anchors 54) formed on the back surface 42 of the base of the fastener 10 are arranged to be exposed to the gap of the mold.

Under the condition, the foamable liquidized resinous material for the main body 60 is fed to the gap of the mold, during which the base 14 of the fastener 12 is in tight contact with the sealing surfaces 20b, 20c of the bottom wall 20 in the guide 10 and the inner surfaces 22a of the side walls 22 to prevent the liquidized resinous material from entering the second section 24b of the groove 24 in the guide 10. On the other hand, the liquidized resinous material smoothly enters the cavities 40 in the fastener base 14 through the indentations 26 formed in the side walls 22 of the guide 10. In this regard, air entering the cavities 40 accompanied with the liquidized resinous material is smoothly discharged therefrom through the slits 48 provided in the box sections 28, whereby the whole interior of the cavities 40 is quickly filled with the liquidized resinous material. Thereafter, the main body 60 is molded by foaming the liquidized resinous material and cooling the same, having the recesses 66 on the surface of the main body 60 at positions corresponding to the spaces occupied by the respective guides 10 in the gap of the mold.

Fig. 7 shows an enlarged cross-section of an area of the main body 60 molded via the insert-molding process using the guide 10 described above for attaching the fastener.

In the recess 66 of the molded main body 60, the base 14 and the embedded portions (the posts 52 and anchors 54) of the fastener 12, except for the major surface 16 (the upper plate 32 of the box section 28), are substantially embedded in the main body 60, whereby the fastener 12 is fixed to the main body 60 while exposing the engaging elements 18 to the inner space of the recess 66. Under the condition, the engaging elements 18 of the fastener 12 exposed to the inner space of the recess 66 are detachably engaged with the corresponding engaging elements 68 consisting, for example, of fiber loops formed on the back surface of the seam 64a of the surface member 64 to fix the surface member 64 onto the surface of the molded main body 60.

In such a manner, through the insert-molding process using the guides 10 described above, the molded main body 60 enters the entirety of the cavities 40 provided in the base 14 of the fastener 12 to substantially encircle the box sections 28. Thereby, the lower plate 34, the side plates 36 and the partitioning plate 38 of the box section 28 (Fig. 3) are fixed into the molded main body 60 together with the posts 52 and the anchors 54 to effectively increase the attachment strength of base 14 to the molded main body 60. This effect can be achievable without changing the structure of the fastener 12 while using the guides 10 alone, having the above-described characteristics.

According to the guide 10, when the fastener 12 is used as means for fixing the surface member, for example, to the vehicle seat, it is possible to assuredly prevent the interconnected portion (molding material around the base 14) between the fastener 12 and the molded main body 60 from breaking even under the unintentional tension applied to the surface member 64 caused by the frequent and abrupt movement of a center of gravity of a person occupying the seat or the intentional tension applied to the surface member 64 due to the replacement thereof, whereby the surface member 64 is removable from the fastener 12 in a precise and stable manner. Also, since the indentations 26 are provided in the side walls 22, the fastener 12 is smoothly removable from the guide 10 when the molded main body 60 is demolded after the insert-molding process has been completed, whereby it is possible to safely demold the molded main body 60 while avoiding the breakage of the interconnected portion between the fastener 12 and the molded main body 60.

As shown in Figs. 4 (a) and 4 (b), in a state wherein the fastener 12 is properly attached to the guide 10, the hooks 58 at the longitudinal opposite ends of the fastener base 14 extend over the sealing surfaces 20b, 20c of the guide 10 to at least partially project outward therefrom. According to such a structure, since the hooks 58 at the longitudinal opposite ends of the fastener 12 enter corners of the recess 66 of the molded main body 60, the breakage of the recess 66'is effectively avoidable. Such an effect is particularly significant in the hook 58 held on the curved sealing surface 20c of the guide 10.

While the present invention has been described with reference to the preferred embodiment illustrated in the drawings, the guide according to the present invention may have various configurations other than the illustrated one. For example, the indentation which is the characteristic constituent feature of the present invention may be provided at least one position in at least one of the pair of side walls in the guide, whereby it is expected that the liquidized material could be in wider contact with the fastener base therethrough during the insert-molding process to enhance the attachment strength of the base to the molded main body. At this time, even though the fastener base is of the above- mentioned structure having a plurality of cavities arranged generally at an equal pitch in the longitudinal direction, provided the indentation is formed at a position in alignment with at least one cavity of the base accommodated in the groove, it is possible to locally increase the attachment strength of the base in that region.

As apparent from the above-mentioned description, according to the present invention, it is possible to provide a guide used for attaching a strip member to a molded main body, capable of improving the attachment strength of the strip member to the molded main body as much as possible without rising the production cost of the strip member itself.