SEWING METHOD TO FORM A TRIM COVER ASSEMBLY AND AUTOMOTIVE SEAT USING THE TRIM COVER ASSEMBLY
A sewing method to form a trim cover assembly for automotive seat, and an automotive seat using the trim cover assembly. Firstly, a first cover material, a second cover material and a backing tape are used and juxtaposed on one another, with their ends aligned with one another, and then sewn together to create a first seam and a sewn connection portion. Such sewn connection portion is cut off into a shortened sewn connection portion. Thereafter, the first cover material and backing tape are turned over relative to the shortened connection portion and sewn together, thereby forming one portion of the trim cover assembly. Another portion of the trim cover assembly may be formed by avoiding use of the backing tape and simply turning over the first cover material relative to the sewn connection portion, and sewing together the thus-turned portions of the first cover material.
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1. Field of the Invention
The present invention relates to a method for sewing together separate cover materials to form a trim cover assembly for automotive seat and also to an automotive seat using such trim cover assembly.
2. Description of Prior Art
In general, the process for producing an automotive seat involves the step of securely attaching a trim cover assembly to a foam padding which forms a body of the seat. Some of such trim cover assemblies are formed from a natural leather material (i.e. such animal skin as cow skin or horse skin) or from an artificial leather material.
Both of those natural and artificial leather materials are, however, less elastic or less extendable and relatively high in stiffness. Such non-flexible property has made it difficult to neatly bend a small local part of the material to form a small bent region therein. In other words, two separate cover materials, no matter of whether they may be a natural leather or artificial leather, are sewn together along their respective end portions, forming a seam therealong, with a certain margin to the seam, and then, the two cover materials are folded outwardly and turned over relative to the seam, such that two end portions respective of the sewn two cover materials, which correspond to the said margin, are defined between the two cover materials, projecting inwardly thereof. In that way, a trim cover assembly with a turned-over corner portion is produced, in which the two end portions of cover materials project inwardly thereof and extend along the seam. Normally, such trim cover assembly is securely attached on the surface of foam padding to produce a complete body of automotive seat, such that the corner portion of the trim cover assembly covers a corresponding corner portion of the foam padding.
However, the foregoing inwardly projected end portions of the trim cover assembly contact and erect on the corner portion of foam padding, thus resulting in objectionable irregular protuberant portions being formed on the outer surface of trim cover assembly and also resulting in an undesired sinuous formation of the seam on the corner portion of the trim cover assembly.
Incidentally, some of the automotive seats are provided with side air bags in one or two lateral bolster portions thereof. A trim cover assembly used on such seat is basically formed by sewing together a seating or back support cover section and at least one lateral bolster cover section, wherein the seating or back support cover section is adapted to cover a corresponding foam padding area for supporting a buttocks or back portion of passenger, and the lateral bolster cover section is adapted to cover at least one lateral bolster are of foam padding for supporting one lateral side of the passenger's body including his or her arms. For the purpose of allowing for inflation of the side air bag, a tear-out or breakable portion is defined in a proper region along a seam between the seating cover section and the lateral bolster cover section, with a stay cloth being sewn with a margin given to that seam at a region substantially corresponding to the breakable portion. With this arrangement, upon inflation of the side air bag, the breakable portion is easily broken and opened due to the stay cloth giving an additional force enough to tear away the seam in conjunction with an outwardly expanding force of the inflated side air bag, so that the air bag may protrude through the opened portion and inflate outwardly therefrom. However, such conventional arrangement has been found defective in involving a troublesome step of providing the stay cloth and sewing the same with the trim cover assembly, which in turn makes the trim cover assembly complicated in structure.
In order to avoid the foregoing drawbacks, one can contemplate on trimming away the the end portions of the two cover sections (or two cover materials) corresponding to a margin to seam so as to provide a small margin to be sewn. With this trimming, it is indeed possible to prevent the above-noted formation of irregular protuberant portions on the corner portions of trim cover assembly. But, practically, it is impossible to use a sewing machine to sew together the end portions of two cover sections in such small margin, because the margin given therein is too small for stable and precise sewing by the sewing machine and also can hardly be retained by a retaining member of the sewing machine. As a result thereof, the two cover sections (or two cover materials) can not be sewn together completely, and thus, it is highly possible that the sewn portion or seam between them will be easily teared away and opened, giving a poor appearance of trim cover assembly.
SUMMARY OF THE INVENTIONIn view of the above-stated drawbacks, it is a purpose of the present invention to provide an improved sewing method to form a trim cover assembly for automotive seat, which effectively prevents formation of the abovementioned objectionable irregular projected portions and sinuous seam on the outer surface of trim cover assembly and prevents the sewn portion there from being torn away and opened, while improving the outer appearance of seat aesthetically.
In order to achieve such purpose, in accordance with the present invention, there is basically provided a sewing method to form a trim cover assembly for automotive seat, which comprises the steps of:
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- providing a first cover material having an outer side, a reverse side; and an end;
- providing a second cover material having an outer side, a reverse side, and an end;
- providing a reinforcing material having one end;
- placing the second cover material on the reinforcing material, such that the reverse side of the second cover material is contacted with the reinforcing material, while the end of the second cover material is aligned with the end of the reinforcing material;
- then, placing the first cover material on the second cover material such that the outer side of the first cover material is contacted with the outer side of the second cover material, while the end of the first cover material is aligned with the thus-aligned two ends of the second cover material and reinforcing material;
- sewing together the thus-juxtaposed first and second cover materials and reinforcing material along a given first sewing line, so that a sewn connection portion is defined therein, with a first seam and a margin to the first seam being created in the sewn connection portion;
- cutting off the sewn connection portion into a shortened sewn connection portion, thus transforming the margin into a reduced margin;
- thereafter, turning over the reinforcing material relative to the first seam in a direction to the reduced margin;
- also turning over the first cover material relative to the first seam in a direction to the reduced margin, so that the reverse side of the first cover material is placed on the reinforcing material and that the shortened sewn connection portion is disposed inwardly of and between the thus-turned-over first cover material and reinforcing material; and
- then, sewing together both the first cover material and the reinforcing material along a given second sewing line, whereupon there are defined one sewn unit of the first cover material and the reinforcing material and a remaining portion of the second cover material in relation to the shortened sewn connection portion, with a second seam being created on the outer side of the first cover material.
In is a second purpose of the present invention to facilitate the ease with which the sewn portion or seam in an area of the trim cover assembly covering a portion of the seat in which a side air bag is provided, thereby allowing the side air bag to easily inflate and tear away the seam to protrude outwardly therefrom.
For that purpose, in accordance with the invention, subsequent to the foregoing step of sewing together both first cover material and reinforcing material along the given second sewing line, there are provided the steps of:
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- avoiding use of the reinforcing material;
- leaving the first cover material placed on the second cover material, with the outer side of the former in contact with the outer side of the latter, and also with the end of the former being aligned with the end of the latter;
- sewing together the first and second cover materials along the given first sewing line, so that a sewn connection portion is defined therein, with the first seam and a margin to the first seam being created in the sewn connection portion, whereupon one end portion and a main body portion are defined relative to the sewn connection portion in the first cover material;
- thereafter, turning over the main body portion of the first cover material relative to the sewn connection portion in a direction to the end portion of the first cover material, so that a reverse side of the main body portion is contacted with a reverse side of the end portion, wherein the reverse sides respective of the main body portion and end portion both correspond to the reverse side of the first cover material; and
- then, sewing together the thus-juxtaposed main body portion and end portion along the given second sewing line, thereby defining one sewn unit of the first cover material, with a second seam being created on the outer side of the first cover material,
- whereby there is formed a portion of the trim cover assembly which is adapted to cover the area in which the side air bag is provided.
Other features and advantages of the present invention will become apparent from reading of the descriptions hereinafter, with reference to the accompanied drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The illustrated seat (S) comprises a seat back (SB) and a seat cushion (SC). As shown in
As far as the seat back (SB) is concerned, referring to
Now, reference is made to
Now, a more specific description will be made of how to form the foregoing first local area of trim cover assembly (C) by use of a known sewing machine (M), with reference to FIGS. 3 to 5.
Reference is now made to
At the present stage, it is observed that, in the thus-sewn trim cover assembly unit, a main body portion (1A) of the first cover material (1), a main body portion (2A) of the second cover material (2), and a main body portion (3A) of the backing tape (3) are defined, so that those three elements (1A, 2A and 3A) and the margin portion (P1) are defined on the opposite sides of and relative to the first thread or first seam (at 4).
Then, as indicated by the arrow in
Thereafter, as shown in
As a result of the above-described sewing process, there is produced the first local area of trim cover assembly unit adapted to cover the corresponding area of the lateral bolster portion (SB-2) of seat back (SB) excepting the above-noted second local area of that trim cover assembly unit. As illustrated, advantageously, a decorative groove (6) is formed along the sewn corner portion of trim cover assembly unit corresponding to the first seam (at 4) and a second decorative seam (5) is defined alongside of such sewn corner portion.
As understandable from
With the above-described sewing processes, It is appreciated that the following advantages are obtained:
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- (i) The first margin or projection (P1), which is defined by the first step of sewing together the backing tape (3) and the first and second cover materials (1) (2), using the first thread (4), can be cut off into a desirably reduced length of margin or projection (P2). Thus, it is possible to not only allow for using any conventional sewing machine to sew together the first and second cover materials (1) (2) with a sufficient margin to seam on which the pressing feed element of the sewing machine is stably contacted, but also minimize objectionable projected points on the outer surface of trim cover assembly (C), which is caused by a conventionally formed margin or projection of a relatively large length in the sewn portion of trim cover assembly unit. In this regard, the reduced margin or projection (P2) does not result in tearing away of the sewn portion or seam (at 4) because the backing tape (3) is sewn with the reduced margin (P2) and serves to reinforce that sewing portion (at 4) against tear.
- (ii) As can be seen from
FIG. 2 , the reduced margin or projection (P2) is inclined and leaned to one side near to the frontal wall (9A) of foam padding (9) or completely reposes thereagainst, due to the fact that both first cover material (1) and backing tape (3) are sewn together via the second thread (5) and stretched outwardly on the foam padding (9), which forcibly inclines the projection (P2) or forcibly reposes the same against the foam padding (9). This effectively prevents objectionable sinuous projection portions from being created on the outer surface of the trim cover assembly (C) which has been found in the prior art as described previously. - (iii) Since the first cover material (1) and backing tape (3) are turned over relative to the first sewn portion (at 4) and sewn together along a sewing line corresponding to the second sewn portion (at 5), a stretching force imparted through the first cover material (1) is dispersed and weakened in such two sewn elements (1) and (3), thus serving to positively prevent the sewn portion (at 4) from being torn away and opened. Further, the second thread or seam (5) serves as an additional decorative seam, thereby aesthetically improving an outer appearance of the seat as a whole.
Turning now back to
Reference is made to
Then, as in
Thereafter, as indicated by the one-dot chain lines in
As shown in
After the completion of the foregoing sewing, as shown in
As understandable from the
Needless to mention, the free end of the first cover material main portion (1A) is sewn with one end of the third cover material (3), as can be seen from
With the above-described sewing processes, It is appreciated that the following advantages are obtained:
-
- (i) As seen in
FIG. 8 , only the second cover material (2) overlies the corner portion of foam padding (9) in which the side air bag (7) is disposed, and further, the first cover material (1) is only sewn with the second cover material end portion (2B) at a point adjacent to the slit (90A). Hence, the inflated side air bag (7), which protrudes and expands through the slit (90A) outwardly of the foam padding (9), can easily tear away the thread (4) and open the connected portion sewn by the thread (4) between the first and second cover materials (1) (2), so that the side air bag (7) will quickly protrude therethrough outwardly from the lateral bolster portion (SB-2) to embracingly protect the lateral body portion of a passenger on the seat (S) against damage and injury. - (ii) Of course, the second thread or seam (5) serves as an additional decorative seam, thereby aesthetically improving an outer appearance of the seat as a whole.
- (i) As seen in
The above described sewing processes may be effected to form the trim cover assembly (C) associated with the seat cushion (SC), or particularly to form one or both the two lateral bolster portions (SC-2) (SC-2) thereof, using a properly preformed first and second cover materials (1) (2) to cover a corresponding foam padding (not shown) configured in a shape of the lateral bolster portion (SC-2).
While having described the present invention so far, it should be understood that the invention is not limited to the illustrated embodiments, but any other modification, replacement and addition will be structurally and methodologically applied thereto within the scopes of the appended claims.
Claims
1. A sewing method to form a trim cover assembly for automotive seat, comprising the steps of:
- providing a first cover material having an outer side, a reverse side; and an end;
- providing a second cover material having an outer side, a reverse side, and an end;
- providing a reinforcing material having one end;
- placing said second cover material on said reinforcing material, such that the reverse side of the second cover material is contacted with the reinforcing material, while said end of the second cover material is aligned with said end of the reinforcing material;
- then, placing said first cover material on said second cover material such that the outer side of the first cover material is contacted with the outer side of the second cover material, while said end of the first cover material is aligned with the thus-aligned two ends of the second cover material and reinforcing material;
- sewing together the thus-juxtaposed first and second cover materials and reinforcing material along a given first sewing line, so that a sewn connection portion is defined therein, with a first seam and a margin to the first seam being created in the sewn connection portion;
- cutting off said sewn connection portion into a shortened sewn connection portion, thus transforming said margin into a reduced margin;
- thereafter, turning over said reinforcing material relative to said first seam in a direction to said reduced margin;
- also turning over said first cover material relative to said first seam in a direction to said reduced margin, so that the reverse side of the first cover material is placed on said reinforcing material and that the shortened connection portion is disposed inwardly of and between the thus-turned-over first cover material and reinforcing material; and
- then, sewing together both said first cover material and said reinforcing material along a given second sewing line, whereupon there are defined one sewn unit of the first cover material and the reinforcing material and a remaining portion of said second cover material in relation to said shortened sewn connection portion, with a second seam being created on the outer side of the first cover material.
2. The sewing method as claimed in claim 1, wherein said automotive seat has an area in which at least one side air bag is provided, and wherein, subsequent to the step of sewing together both said first cover material and said reinforcing material along said given second sewing line, the sewing method further comprising the steps of:
- avoiding use of said reinforcing material;
- leaving said first cover material placed on said second cover material, with the outer side of the former in contact with the outer side of the latter, and also with the end of the former being aligned with the end of the latter;
- sewing together said first and second cover materials along said given first sewing line, so that a sewn connection portion is defined therein, with the first seam and a margin to the first seam being created in said sewn connection portion, whereupon one end portion and a main body portion are defined relative to said sewn connection portion in said first cover material;
- thereafter, turning over said main body portion of said first cover material relative to said sewn connection portion in a direction to said end portion of the first cover material, so that a reverse side of said main body portion is contacted with a reverse side of said end portion, wherein said reverse sides respective of said main body portion and said end portion both correspond to the reverse side of the first cover material; and
- then, sewing together the thus-juxtaposed main body portion and end portion along said given second sewing line, thereby defining one sewn unit of said first cover material, with a second seam being created on the outer side of said main body portion of the first cover material,
- whereby there is formed a portion of the trim cover assembly which is adapted to cover said area in which said side air bag is provided.
2. The sewing method as claimed in claim 1, wherein a sewing machine is used to effect the step of sewing together said first and second cover materials and said reinforcing material as well as the step of sewing together said first cover material and said reinforcing.
3. The sewing method as claimed in claim 1, wherein said reinforcing material is a backing tape or a back cloth.
4. The sewing method as claimed in claim 1, wherein a sewing machine provided with a cutter is used to sew together said first and second cover materials and said reinforcing material, while simultaneously operating said cutter to cut off said sewn connection portion, thereby transforming said margin into said reduced margin.
5. The sewing method as claimed in claim 1, wherein said first and second cover materials are each formed from one selected from the groups consisting of an artificial leather material and a natural leather material including an animal skin.
6. The sewing method as claimed in claim 1, wherein said first and second cover materials are each of a two-layer lamination structure comprising an outer cover layer and a foam wadding layer, and wherein said outer cover layer and said foam padding layer respectively correspond to said outer side and said reverse side associated with each of said fist and second cover materials.
7. A trim cover assembly formed by the sewing method as claimed in claim 1, which is used to cover at least one corner portion of an automotive seat in such a manner that said second seam extends alongside of said at least one corner portion and that said shortened sewn connection portion is inclined to or leaned against one surface of said at least one corner portion.
8. The trim cover assembly according to claim 7, wherein said at least one corner portion is a lateral bolster portion of the automotive seat.
9. An automotive seat using the trim cover assembly formed by the method as claimed in claim 1.
Type: Application
Filed: Nov 14, 2003
Publication Date: May 19, 2005
Applicant: TACHI-S CO., LTD. (Tokyo)
Inventor: Takuya Hori (Tokyo)
Application Number: 10/706,973