TRIM COVER FOR SEAT

Abstract: The trim cover consists of one piece of wide material composed of a laminated upper skin (5), wadding (6) and a lower substrate cloth and which is suitably used to make a bucket seat. A bucket seat is made not by joining to one another separately-cut pieces, which are to constitute the parts of the bucket seat, of such a material as mentioned above, but by folding such one piece of wide material at connecting lines on such portions of the material that are to constitute the parts of the bucket seat. The connecting lines are defined in advance to form grooves in predetermined portions of the upper surface of the material. The material is thus set up in a three-dimensional shape.

Description: Technical Field This invention relates to a seat for use in a vehicle or the like, which seat can be easily finished to show a beautiful appearance and can be made with decreased man-hours, hence, at a reduced cost. Background Art Prior art trim covers of seats will be briefly described with reference to Figs. 13 to 16, before describing the present invention in detail. Figs. 13 and 14 show a prior art trim cover covering a front back of a seat for use in, for example, a vehicle. Fig. 13 is a planar developed view of a trim cover material consisting of a cover member, a filler pad and a backing cloth. As shown in Fig. 13, the trim cover material is divided by cutting it into four parts, that is, a seat base part 1, a pair of flap parts 2 on both sides of the seat base part 1, and an upper extension 3 of the seat base part 1. Fig. 14 is a schematic perspective view showing that these parts 1, 2 and 3 are assembled into a three-dimensional shape as by machine sewing, and the flap parts 2 form a three-dimensional bucket. Lines a-b-c of the flap parts 2, lines a'-b' of the upper extension 3 of the seat base part 1 and lines b'-c' of the seat base part 1 in Fig. 13 are joined to form lines a-b-c of the three-dimensional seat shape shown in Fig. 14. Therefore, the individual parts 1, 2 and 3 shown in Fig. 13 are developed on a plane and cut while taking the three-dimensional seat shape into consideration. Figs. 15 and 16 show a trim cover of a front cushion of a seat for use in, for example, a vehicle. Individual parts 1, 2 and 4 of the trim cover shown in Figs. 15 and 16 are arranged and assembled into a three-dimensional shape in a manner similar to that described with reference to Figs. 13 and 14. The seat base part 1 is cut to have an extra length l at each of its upper and lower ends, becuase it is shaped into a curved form as shown by lines a-b-c in Fig. 16. As described above, each of the front back and the front cushion is composed of at least four parts. A trim cover of a rear seat (not shown) is composed of a further larger number of parts, and material losses occur inevitably during cutting and assembling these parts. A skilled worker is required for assembling those parts as by a sewing machine, and, because of manual making, many man-hours are required. Further, the finished seats are not always uniform in the dimensional accuracy, etc., and rejects are produced due to the presence of wrinkles which impair the otherwise beautiful appearance. JP-U-60-20900 discloses a single piece trim cover consisting of a cover member, a filler pad and a backing cloth. In order to avoid wrinkles forming on the cover member when the trim cover is bent into a three-dimensional shape, JP-U-60-20900 provides to insert a special porous adhesive material between the cover member and the filler pad. This material is subsequently subjected to high frequency welding to adhere it to cover member and filler pad. This results in two main drawbacks: highly expensive and very complex high-frequency molds are required, and difficulties arise in correctly positioning the different parts within the mold to avoid displacement during molding steps. It is therefore an object of the present invention to provide a novel trim cover of a seat which solves the prior art problems described above. Disclosure of the Invention In accordance with one aspect of the present invention, there is provided a trim cover of a seat comprising a single planar material in the form of a laminate consisting of a cover member, at least in part coupled with a filler pad and a backing cloth to form a seat base part, a pair of flap parts on both sides of the seat base part, and an upper extension or a rear extension of the seat base part joined together by a plurality of joint lines (w) partitioning the individual parts and the extention, each of said joint lines (w) having a groove (v) formed thereon along which said laminate is bent to build up a three-dimensional shape of the seat, characterized in that said laminate is shaped in three-dimensional seat form utilizing local stretching and deformation of the material in the neighborhood of said joint lines between said flap parts, base part and upper or rear extention of the seat. In accordance with the other aspect of the invention, there is a process as defined in Claim 9. Preferred embodiments of the invention are defined in dependant claims 2 to 8. Brief Description of the Drawings Figs. 1 through 12 relate to the present invention in which: Fig. 1 is a plan view of a front back formed of a single trim cover material; Fig. 1A is a plan view of a modification of the front back shown in Fig. 1; Fig. 2 is a perspective view of the front back shaped into its three-dimensional form; Fig. 3 is a planar developed view of a front cushion formed of a single trim cover material; Fig. 4 is a perspective view of the front cushion shaped into its three-dimensional form; Figs. 5 and 6 are sectional views of part of the trim cover shown in Fig. 1 when thermally welded at a joint line; Figs. 7 and 8 are sectional views taken on one of the lines A-B-C in Fig. 2; Fig. 9 is a sectional view taken along the line c-d in Fig. 4; Fig. 10 is a sectional view taken along the line e-f in Figs. 1 and 2; Fig. 11 is a sectional view taken along the line g-h in Fig. 2; and Fig. 12 is a sectional view taken along the line i-j in Fig. 2. Figs. 13 through 16 relate to the prior art in which: Fig. 13 is a plan view of a prior art trim cover; Fig. 14 is a perspective view of the prior art trim cover; Fig. 15 is a plan view of planar cut parts of the prior art trim cover; and Fig. 16 is a perspective view of the prior art trim cover formed by assembling the individual parts as by sewing with a sewing machine. Best Mode for Carrying Out the Invention Preferred embodiments of the present invention will now be described in detail with reference to Figs. 1 through 12. Fig. 1 is a planar developed view of a front back formed of a single trim cover material, and Fig. 2 is a perspective view of the front back shaped into its three-dimensional form. The single trim cover material includes a three-layer laminate consisting of a cover member, a thin filler pad and a backing cloth. Sections taken on the lines A-B-C, D, E and F in Fig. 1 are as shown in Fig. 5 or 6. As will be seen in Fig. 5 or 6, any one of joints w between a seat base part 1, flap parts 2 and an upper extension 3 of the seat base part formed of a three-layer laminate consisting of a cover member 5, a filler pad 6 and a backing cloth 7 is formed with a triangular groove v. The joint w is provided by thermal welding such as high-frequency welding, ultrasonic welding or hot pressing. This joint w may be provided by machine sewing. Each of joint lines of the joints w (that is, boundaries between the parts 1, 2 and 3) is in the form of a narrow web, a fine line, a series of fine perforations or a series of stitches formed by machine sewing. Each of these grooves v is bent as shown in Fig. 7 or 8 which is a sectional view taken on one of the lines A-B-C in, for example, Fig. 2. Figs. 11 and 12 are sectional views taken along the respective lines g-h and i-j extending between the seat base part and the bucket part in Fig. 2. It will be seen that the angle of bend relative to the horizontal plane is larger in Fig. 11 than in Fig. 12. Thus, the joint w is forced downward to pull the cover member 5 downward, and the flap parts 2 provide a wrinkle-free bucket structure. In Figs. 11 and 12, the portions of the filler pad 6 and backing cloth 7 on the right-hand side of the joint w may be eliminated to leave the cover member 5 above. Even in such a case, the three-dimensional bucket seat can be made because of the presence of the groove v at the joint w. Similarly, in a rear seat (not shown) too, a single trim cover material can be used, and the portions of the filler pad 6 and backing cloth 7 except those of the seat base part 1 can be eliminated. At cross-hatched portions in Fig. 2, the flap parts 2 (the bucket part) are stretched relative to the seat base part 1 and the upper extension 3 of the seat base part 1. Fig. 10 is a sectional view taken along the line e-f in Fig. 1 or 2. It will be seen in Fig. 2 that, although the cover member 5 of the trim cover forming the upper extension 3 of the seat base part 1 is not stretched, the portion of the cover member 5 in each of the crossed-hatched areas (the cover member 5 in the groove v in Fig. 10) is stretched. The above state means that the thickness of the trim cover portion in each of the cross-hatched areas is decreased from T to t, while the length is increased from L to (L+l) as shown in Fig. 9 which is a sectional view taken along the line c-d in Fig. 4. In Fig. 1A, lines A-C, B-B, D, E and F are formed by bonding with thermal welding or machine sewing. In the case of sewing with a sewing machine, extensions d', e' and f' of the respective lines D, E and F are sewn in intersecting relation with the line B-B, and there is thus no possibility that the lines D, E and F are frayed relative to the line B-B. Since the line B-B is pulled inward during assembling the bucket seat, the line B-B forms the bottom line of the bucket shape. Therefore, when the extensions d', e' and f' extending toward and onto the upper extension 3 of the seat base part 1 have a short length, they are drawn into the bottom of the bucket seat so that they are not visible from the outside. Fig. 1A illustrates an example in which the lines D, E and F as well as the line B-B having both ends terminating at inner positions of the seat are sewn without causing loosening. In this case, a sewing machine capable of, for example, double sewing, final sewing and back stitching can be used for the above and other purposes. Fig. 3 is a planar developed view of a front cushion formed of a single trim cover material, and Fig. 4 is a perspective view of the front cushion shaped into its three-dimensional form. Any description of the method for making such a front cushion is unnecessary because the method is similar to that of or an application of the method of making the front back shown in Figs. 1 and 2. In the front cushion shown in Fig. 3, hatched triangular portions of the rear extension 4 of the seat base part 1 are cut away or bent outwardly to form corners. The outwardly bent portions are sewn to or inserted into corresponding recesses of a molded polyurethane foam and bonded thereto. This technique can be applied to other portions such as those of a front back. That is, the above technique is applicable to a case where formation of the desired three-dimensional seat shape by a single trim cover is difficult due to a low stretchability of the trim cover or a case where wrinkles tend to appear on the three-dimensional seat although the single trim cover is sufficiently stretchable. In such a case, the trim cover is locally cut to remove unnecessary trim cover portions, and the remaining trim cover portions are sewn together, or separately prepared trim cover portions are sewn onto areas where shortage of the trim cover occurs. The above description has not referred to side parts (peripheral parts) of the trim cover covering the seat. However, it is apparent that such side parts are commonly normally connected to the outer ends of the seat base part and flap parts of the trim cover and are supported on a supporting member such as a cushion or a frame. In the present invention, the single trim cover shown in planar developed view in Fig. 1 or 3 is shaped into a three-dimensional form as shown in Fig. 2 or 4. The present invention provides the following advantages: a) The joint w and the groove v shown in Fig. 5 or 6 act to accurately determine the portion where the trim cover is to be bent. b) The deformation of the trim cover shown by l in Fig. 9 or the inward drawing of the cover member 5 shown in Fig. 11 can be provided when the trim cover is flexible even if it may not be fully stretchable. It is apparent that the shaping is easier when the trim cover is fully stretchable. c) When the cover member 5 and the filler pad 6 are bonded together, wrinkles attributable to deformation of the cover member 5 only do not occur because the filler pad 6 is integrally bonded to the cover member 5. d) Even when the trim cover consists of the cover member 5 only without the provision of the filler pad 6 and the backing cloth 7 or even when the trim cover consists of the cover member 5 and the filler pad 6 only without the provision of the backing cloth 7, the trim cover can be shaped into the desired three-dimensional form provided that the grooves v are formed on the trim cover. e) In the prior art trim cover shown in Fig. 14, the joint a-b-c is convex at the portion in contact with a molded polyurethane foam (not shown). In the trim cover of the present invention, the joint w is not convex as shown in Fig. 7 or 8, and the trim cover conforms with the outer shape of a molded polyurethane foam. Therefore, the trim cover can be easily and reliably bonded to the molded polyurethane foam, so that the three-dimensional shape after shaping can be accurately maintained. f) The present invention obviates the defects of the prior art trim cover. That is, the present invention decreases the number of required parts, decreases the cutting losses and the losses of the material during joining the parts, eliminates the necessity for a skilled worker, and eliminates occurrence of wrinkles and other defects. Therefore, the quality of seats can be improved, and the cost of the seats can be reduced. Industrial Applicability The present invention is not only applicable to the trim cover of the bucket seats but also applicable to rear seats and other similar articles such as vehicle's inner equipments and articles of furniture.

Claims: A trim cover of a seat comprising a single planar material in the form of a laminate consisting of a cover member (5), at least in part coupled with a filler pad (6) and a backing cloth (7) to form a seat base part (1), a pair of flap parts (2) on both sides of the seat base part, and an upper extension (3) or a rear extension of the seat base part joined together by a plurality of joint lines (w) partitioning the individual parts and the extension, each of said joint lines (w) having a groove (v) formed thereon along which said laminate is bent to build up a three-dimensional shape of the seat, characterized in that said laminate is shaped in three-dimensional seat form utilizing local stretching and deformation of the material in the neighborhood of said joint lines between said flap parts, base part and upper or rear extension of the seat. A trim cover according to claim 1, wherein said laminate is bent at said grooves (v) by stretching the corresponding portions of the cover member (5) or by pulling the cover member toward the backing cloth (7). A trim cover according to claim 1, wherein unnecessary corner portions protruding from the boundaries between the flap parts (2) and the seat base part (1) or the rear extension (3) of the seat base part are cut away to shape the trim cover into the three-dimensional seat form. A trim cover according to claim 3, modified in that said corner portions are bent outwardly and bonded to a molded foam cushion supporting said trim cover after being inserted into corresponding recesses of the said molded foam cushion. A trim cover according to any previous claim, wherein part of the filler pad (6) and/or part of the backing cloth (7) is removed from the trim cover. A trim cover according to claim 1, wherein said joint line and said groove (B-B) are formed between said seat base part (1) and said upper extension (3) of said seat base part, and a plurality of longitudinal grooves (D, E, F) are formed on said seat base part in a state where the trim cover member of said seat base part is stretched. A trim cover according to claim 6, wherein said plural longitudinal grooves (D, E, F) formed on said seat base part have their ends (d', e', f') extended partly toward and onto said upper extension beyond said joint line and said groove (B-B). A seat comprising a molded foam cushion and a single piece trim cover according to any claim 1 to 7. A process for preparing a seat trim cover, said cover comprising a sigle piece of laminated material consisting of a cover member (5), a filler pad (6) and a backing cloth (7) and comprising a seat base part (1), lateral flap parts (2), and an upper extension or rear extension (3; 4) of the seat base part, said process comprising the steps of forming a plurality of joint lines (w) having grooves (v) thereon, and bending the trim cover along said grooves, characterized in that three-dimensional seat form is obtained by locally deforming and stretching said trim cover in the neighborhood of said joint lines between said flap parts, base part and upper or rear extension of the seat.

Inventors: URAI MUNEHARU, URAI, MUNEHARU
Applicants: TACHI S CO, TACHI-S CO. LTD.
Application year: 1988
Main classification: B68G7
IPC codes: B60N2, A47C31