Force distribution structure

Abstract

To provide a webbing structure which enables breaking of a burst line and deployment of an airbag to be performed quickly even if a frame curves.SOLUTION: A webbing structure includes: a pair of webbings which covers a frame provided at a seat of a vehicle and an airbag in a cylindrical form; a burst line formed by sewing first edges of the webbings and a cover of the seat to each other; and a fastener which connects second edges of the webbings. The frame has a curved part protruding toward the burst line. Each webbing has a reduction part in which a peripheral length of the webbing is locally reduced near the fastener covering the curved part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a force cloth structure that covers an airbag of a vehicle seat.

Background Art

[0002] There is known a side airbag that protects an occupant sitting on a seat during a side collision of a vehicle. Patent Document 1 discloses a side airbag fixed to the side surface of a side frame that constitutes a seat back. The side airbag has an inflater that generates gas in response to an impact associated with a side collision, and a bag that expands by the gas from the inflater and receives the occupant. Such a side airbag is covered in a cylindrical shape with a force cloth together with the side frame. This force cloth is composed of two pieces of cloth. The front edges of the two pieces of cloth are sewn to the edge of the seat cover to form a burst line. The rear edges of the two pieces of cloth are connected by a fastener. The force cloth is pulled by receiving the load when the bag expands, thereby breaking the burst line. Due to the breakage of the burst line, the bag is deployed while expanding to the side of the occupant.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Even when the side frame is curved, it is desirable that the burst line breaks and the bag unfolds quickly. The side frame may be curved so as to protrude forward of the vehicle in order to form a seat back that easily follows the line of the back of an occupant sitting on the seat. When the side frame including the curved portion and the side airbag are covered with a force cloth, a gap is formed between the rear surface of the curved portion and the force cloth. When the bag inflates, the force cloth into which a load is input behaves so as to narrow the gap by approaching the rear surface of the curved portion. Such behavior of the force cloth becomes a factor inhibiting the quick transmission of the load to the burst line.

[0005] The present invention has been made in view of the above circumstances, and one of its objects is to provide a force cloth structure capable of quickly breaking a burst line and deploying an airbag even when a frame such as a side frame is curved.

Means for Solving the Problems

[0006] A first force cloth structure of the present invention includes a set of force cloths that cylindrically cover a frame and an airbag provided on a vehicle seat, a burst line formed by sewing together first edges of the force cloths and a cover of the seat, and a fastener that connects second edges of the force cloths to each other. The frame has a curved portion that protrudes toward the burst line, and the force cloth has a shortened portion in the vicinity of the fastener that covers the curved portion and locally reduces the perimeter of the force cloth.

Effects of the Invention

[0007] By having the shortening portion, the above-described force fabric structure can quickly break the burst line of the airbag and deploy the airbag. The shortening portion is a location where the perimeter of the force fabric is locally smaller compared to other locations outside the shortening portion. The force fabric with the shortening portion can approach the curved portion more closely compared to the force fabric without the shortening portion. That is, the gap formed between the force fabric and the back surface of the curved portion can be reduced. By reducing this gap, the force fabric can quickly transmit the load associated with the inflation of the airbag to the burst line. As a result, the burst line can be appropriately broken, and the airbag can be quickly deployed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0009] The details of the force distribution structure according to the embodiment will be described with reference to the drawings. The same reference numerals in the figures denote the same components. The sizes of the members shown in each drawing are expressed for the purpose of clarifying the description and do not necessarily represent the actual dimensional relationships. In the figures, "FR" indicates the front of the vehicle, "RR" indicates the rear, "UP" indicates the upper side, "LWR" indicates the lower side, "LH" indicates the left side, and "RH" indicates the right side. Also, in the figures, "IN" indicates the inside of the vehicle, and "OUT" indicates the outside of the vehicle. The inside of the vehicle is the side closer to the bisector of the vehicle width from the left and right sides of the vehicle. The outside of the vehicle is the side farther from the bisector of the vehicle width to the left and right sides of the vehicle.

[0010] <<Embodiment 1>> (Overview) The details of the force distribution structure according to Embodiment 1 will be described with reference to FIGS. 1 to 6. The force distribution structure according to Embodiment 1 is used for the side airbag in the seat 1 of the vehicle. As shown in FIGS. 2 and 4, this force distribution structure includes a set of force distribution fabrics 30, a burst line 40, and a fastener 50. The set of force distribution fabrics 30 cylindrically covers the side frame 12s and the airbag 20 provided on the seat back 12 of the vehicle. The burst line 40 is formed by sewing the first edges of the force distribution fabrics 30, that is, the front edges in this example, and the seat cover 14. The fastener 50 connects the second edges of the force distribution fabrics 30, that is, the rear edges in this example. On the other hand, the side frame 12s has a curved portion that protrudes toward the burst line 40. In this example, the side frame 12s has a curved portion that protrudes forward of the vehicle. The curved portion is a lower curved portion 12bc, which will be described later with reference to FIGS. 1 and 3. One of the features of the force distribution structure according to Embodiment 1 is that, as shown in FIGS. 2 and 4, the force distribution fabric 30 has a shortened portion 32s that locally reduces the perimeter of the force distribution fabric 30 in the vicinity of the fastener 50 that covers the curved portion. Hereinafter, the outline of the configuration of the seat 1 will be described, and then the details of the force distribution structure will be explained.

[0011] (Seat) As shown in FIG. 1, the seat 1 includes a seat cushion 11, a seat back 12, and a headrest 13. In FIG. 1, the power cloth is not shown. The seat 1 in this example is the driver's seat. The seat cushion 11 constitutes the seating surface of the occupant. The seat back 12 supports the occupant's back. The headrest 13 supports the occupant's head. Each of the seat cushion 11, the seat back 12, and the seat cushion 11 is covered with a seat cover 14. Since known configurations can be used for the seat cushion 11 and the headrest 13, detailed descriptions thereof are omitted.

[0012] The seat back 12 having the power cloth structure in this example is configured to be tiltable with respect to the seat cushion 11. As shown in FIGS. 1 to 4, this seat back 12 has a seat back frame 12f built therein. The seat back frame 12f is formed in a frame shape by a left and right side frame 12s, an upper frame connecting the upper end portions of both side frames 12s, and a lower frame connecting the lower end portions of both side frames 12s. The upper frame and the lower frame are not shown. Also, in FIG. 4, the hatching of members other than the power cloth 30 and the side frame 12s is omitted.

[0013] In FIGS. 1 to 4, the side frame 12s on the right side of the vehicle is shown. The side frame 12s is curved in an S shape in order to make the seat back 12 follow the shape of the occupant's back line. Specifically, as shown in FIGS. 1 and 3, the side frame 12s has an upper curved portion 12tc and a lower curved portion 12bc. Both curved portions are curved in an arc shape. The upper curved portion 12tc is curved so as to protrude rearward from the upper part to the middle part of the side frame 12s. The lower curved portion 12bc is curved so as to protrude forward from the middle part to the lower part of the side frame 12s. The lower curved portion 12bc corresponds to the curved portion defined in claim 1. An airbag 20 described later is fixed to this lower curved portion 12bc.

[0014] Furthermore, as shown in FIG. 4, the seat back 12 of this example has side supports 15 that support the occupant from the left and right. The seat cover 14 of the seat back 12 has a side support cover 15c that covers the left and right sides of the front surface of the seat back 12, a side cover 14s that covers the side surface of the seat back 12, and a rear cover 14r that covers the rear surface of the seat back 12. The outer edge of the side support cover 15c, the right edge in this example, is sewn to the front edge of the side cover 14s. This sewing location is sewn together with the force cloth 30 as described later to form the burst line 40. The inner edge of the side support cover 15c is sewn to the outer edge of the main cover 14m that covers the central portion of the seat back 12. The rear edge of the side cover 14s is sewn to the outer edge of the rear cover 14r.

[0015] Inside the seat back 12 covered by the seat cover 14, a pad 16 that serves as a cushioning material is built in. In FIG. 4, pads 16 are arranged in front of and behind the side frame 12s.

[0016] (Airbag) As shown in FIG. 1, an airbag 20 is fixed to the outside of the side frame 12s of the seat back 12 described above. In this example, the airbag 20 is fastened by bolts to the right side surface that forms the lower curved portion 12bc of the side frame 12s. The airbag 20 includes a sensor, an inflater, a bag, and a package (not shown).

[0017] The sensor detects an impact associated with a collision of the vehicle. In this example, the sensor is provided to detect an impact during a side collision of the vehicle. The inflater generates gas in response to a signal from the sensor. The bag is a bag-shaped member that inflates with the gas from the inflater and receives the occupant. The bag is folded in a predetermined folding manner and stored in a rectangular parallelepiped package together with the inflater. The package is arranged such that its long side generally extends along the vertical direction of the side frame 12s. Any of the sensor, the inflater, the bag, and the package can utilize a known configuration.

[0018] (Reinforcing cloth) As shown in Fig. 2, the reinforcing cloth 30 is a cloth that cylindrically covers the side frame 12s and the airbag 20. This reinforcing cloth 30 has a function of transmitting the load accompanying the inflation of the bag to the burst line 40 and guiding the deployment direction of the bag. The reinforcing cloth 30 is composed of a set of cloths. In this example, it includes an outer reinforcing cloth 31 mainly disposed outside the side frame 12s and an inner reinforcing cloth 32 mainly disposed inside the side frame 12s. As shown in Fig. 4, the outer reinforcing cloth 31 extends from the rear surface of the side frame 12s, passes through the rear surface of the airbag 20, and extends toward the front edge of the side cover 14s through the space between the side cover 14s and the right side surface of the airbag 20. The inner reinforcing cloth 32 extends from the rear surface of the side frame 12s, passes through the left side surface and the front surface, and extends toward the right side edge of the side support cover 15c. The right side edge of the side support cover 15c and the front edge of the side cover 14s are folded inward and overlapped. On the other hand, the front edge of the outer reinforcing cloth 31 and the front edge of the inner reinforcing cloth 32 are folded inward so as to sandwich the overlapping portion of the right side edge of the side support cover 15c and the front edge of the side cover 14s. That is, in order from the outside of the vehicle, the front edge of the outer reinforcing cloth 31, the front edge of the side cover 14s, the right side edge of the side support cover 15c, and the front edge of the inner reinforcing cloth 32 are overlapped. These overlapping portions are sewn to form the burst line 40. The burst line 40 is the portion where the load accompanying the inflation of the bag is input to the reinforcing cloth 30 and is broken. Due to the breakage of the burst line 40, the bag is deployed outside the seat cover 14. The burst line 40 is the region where the front edge of the outer reinforcing cloth 31 and the front edge of the inner reinforcing cloth 32 are overlapped among the sewing portions of the right side edge of the side support cover 15c and the front edge of the side cover 14s.

[0019] The unfolded outer force cloth 31 is shown in Fig. 5. The outer force cloth 31 in this example has a rectangular portion 31r and a fan-shaped portion 31f connected to the rectangular portion 31r. A mountain fold line 31m is provided approximately at the center of the rectangular portion 31r. By folding the rectangular portion 31r along this mountain fold line 31m, the first edge 31fe of the rectangular portion 31r is overlapped with the second edge 31se of the rectangular portion 31r. The first edge 31fe and the second edge 31se are sewn in a state of being overlapped with each other. As a result, the mountain fold line 31m constitutes the trailing edge of the outer force cloth 31. The trailing edge of the outer force cloth 31 is connected to a tape 51 of a fastener 50 described later. The trailing edge of the outer force cloth 31 is linear. The second edge 31se of the rectangular portion 31r is also the short edge 31S of the fan-shaped portion 31f. The long edge 31L of the fan-shaped portion 31f corresponds to the leading edge of the outer force cloth 31. In this example, as shown in Figs. 2 and 4, the first edge 31fe is folded inside the cylindrical force cloth 30, but the first edge 31fe may be folded outside the cylindrical force cloth 30.

[0020] The unfolded inner force cloth 32 is shown in Fig. 6. The inner force cloth 32 in this example has a rectangular portion 32r and a T-shaped portion 32t connected to the rectangular portion 32r. A mountain fold line 32m is provided approximately at the center of the rectangular portion 32r. By folding the rectangular portion 32r along this mountain fold line 32m, the first edge 32fe of the rectangular portion 32r is overlapped with the second edge 32se of the rectangular portion 32r. The first edge 32fe and the second edge 32se are sewn in a state of being overlapped with each other. As a result, the mountain fold line 32m constitutes the trailing edge of the inner force cloth 32. The trailing edge of the inner force cloth 32 is connected to a tape 51 of a fastener 50 described later. The trailing edge of the inner force cloth 32 is linear. The second edge 32se of the rectangular portion 32r is also the short edge 32S of the T-shaped portion 32t. The long edge 32L of the T-shaped portion 32t corresponds to the leading edge of the inner force cloth 32. In this example, as shown in Figs. 2 and 4, the first edge 32fe is folded inside the cylindrical force cloth 30, but the first edge 32fe may be folded outside the cylindrical force cloth 30.

[0021] By having the fan-shaped portion 31f of the outer force cloth 31 and the T-shaped portion 32t of the inner force cloth 32, when the side frame 12s and the airbag 20 are covered with the force cloth 30, the tension in each part of the force cloth 30 can be made uniform. By making this tension uniform, it is possible to suppress the occurrence of wrinkles on the surface of the seat cover 14.

[0022] (Fastener) The trailing edge of the outer force cloth 31 and the trailing edge of the inner force cloth 32 are connected via a fastener 50. As shown in FIGS. 2 and 4, the fastener 50 includes a pair of tapes 51, an element group 52 provided along one side edge of each tape 51, and a slider 53 slidably mounted along the element group 52 of both tapes 51. The fastener 50 is opened and closed by the engagement of the element group 52 accompanying the sliding of the slider 53. Specifically, the fastener 50 closes by sliding the slider 53 along the longitudinal direction of the tape 51 to engage the element group 52. Also, the fastener 50 opens by sliding the slider 53 in the opposite direction along the longitudinal direction of the tape 51 to disengage the engagement of the element group 52. FIG. 2 shows the fastener 50 in a closed state.

[0023] Either one of the pair of tapes 51 is sewn to the trailing edge of the outer force cloth 31, and the remaining tape 51 is sewn to the trailing edge of the inner force cloth 32. In this example, the fastener 50 is sewn to the outside of the cylindrical force cloth 30. However, the fastener 50 may be sewn to the inside of the cylindrical force cloth 30. Generally, when the element groups 52 are engaged with each other, the fastener 50 is easily bent flatwise such that either the front or back surface of the tape 51 is on the inner side of the bend and the other is on the outer side of the bend. On the other hand, the fastener 50 is difficult to bend edgewise such that either one of the both side edges of the tape 51 with the element groups 52 engaged with each other is on the inner side of the bend and the other is on the outer side of the bend. If the trailing edges of the outer force cloth 31 and the inner force cloth 32 are linear, it is easy to sew the fastener 50 to each linear tape 51 without bending the fastener 50 edgewise. A commercially available fastener can be used for this fastener 50. In this example, the fastener 50 is arranged to face the rear surface of the side frame 12s. A gap 60 is formed between the rear surface of the lower curved portion 12bc of the side frame 12s and the fastener 50. As shown in FIG. 3, this gap 60 has an arcuate shape when the seat 1 is viewed from the side of the vehicle.

[0024] (Shrinkage portion) As shown in FIGS. 2 to 4, the force cloth 30 has a shrinkage portion 32s where the perimeter of the force cloth 30 is locally reduced. The shrinkage portion 32s is a location where the perimeter of the force cloth 30 is locally smaller than other locations outside the shrinkage portion 32s. In this example, the shrinkage portion 32s is provided only on the inner force cloth 32. When the shrinkage portion 32s is provided on the inner force cloth 32, wrinkles due to the shrinkage portion 32s do not appear on the side cover 14s. When the shrinkage portion 32s is provided on the outer force cloth 31, the side cover 14s is overlapped with the shrinkage portion 32s. Therefore, wrinkles due to the shrinkage portion 32s may appear on the surface of the side cover 14s. When the shrinkage portion 32s is provided on the inner force cloth 32, the shrinkage portion 32s and the side cover 14s do not overlap, suppressing the occurrence of wrinkles. Different from this example, the shrinkage portion 32s may be provided only on the outer force cloth 31, or the shrinkage portion 32s may be provided on both the inner force cloth 32 and the outer force cloth 31. That is, the number of shrinkage portions 32s may be one or more.

[0025] As shown in FIGS. 2 and 4, the shortening portion 32s in this example is composed of an overlapping portion formed by folding a part of the inner force cloth 32. Specifically, this shortening portion 32s is formed by folding a part of the inner force cloth 32 in a Z-shape or an S-shape and sewing it to hold the folded state. The sewing position of the shortening portion 32s in this example is provided at a position adjacent to the sewing portion at the location where the first edge 32fe and the second edge 32se in FIG. 6 are overlapped. Such a shortening portion 32s can be easily formed by sewing the inner force cloth 32 and the tape 51 of the fastener 50 and then additionally sewing the portion where a part of the inner force cloth 32 is folded.

[0026] The position of the shortening portion 32s along the axis in the cylindrical force cloth 30 may be provided at a location corresponding to a part of the total length of the lower curved portion 12bc. For example, the shortening portion 32s may be provided so as to include the location where the distance between the force cloth 30 and the rear surface of the lower curved portion 12bc is the largest when there is no shortening portion 32s. In this example, the shortening portion 32s is provided at approximately the middle portion in the extending direction of the lower curved portion 12bc. In FIG. 3, the location where the shortening portion 32s is provided is indicated by a broken-line rectangle.

[0027] The position of the shortening portion 32s around the axis in the cylindrical force cloth 30 is in the vicinity of the fastener 50 that covers the lower curved portion 12bc. By providing the shortening portion 32s in the force cloth 30 in the vicinity of the fastener 50 that covers the lower curved portion 12bc, it is easy to reduce the gap 60 formed between the force cloth 30 and the lower curved portion 12bc. In this example, as shown in FIG. 4, the shortening portion 32s is provided at a position adjacent to the sewing location where the first edge 32fe and the second edge 32se of the inner force cloth 32 are overlapped.

[0028] In this example, the fastener 50 is arranged to face the rear surface of the lower curved portion 12bc. As shown in FIGS. 3 and 4, when the bag expands, the fastener 50 and the force distribution cloth 30 near the fastener 50 behave so as to narrow the gap 60 by approaching the rear surface of the lower curved portion 12bc. This behavior prevents the load input to the force distribution cloth 30 from being quickly transmitted to the burst line 40 as the bag expands. Therefore, by providing the shortening portion 32s so as to make the gap 60 as small as possible, the amount of displacement in which the fastener 50 and the force distribution cloth 30 near the fastener 50 approach the rear surface of the lower curved portion 12bc can be reduced. If this amount of displacement is small, the force distribution cloth 30 can quickly transmit the load accompanying the expansion of the bag to the burst line 40. As a result, the burst line 40 can be appropriately broken, and the airbag 20 can be quickly deployed.

[0029] On the other hand, as shown in FIGS. 9 and 10, when there is no shortening portion 32s, a large gap 60 is provided between the side frame 12s and the rear surface of the airbag 20 and the fastener 50 and the force distribution cloth 30 near the fastener 50. When this gap 60 is large, when the bag expands, the fastener 50 and the force distribution cloth 30 near the fastener 50 can be greatly displaced by approaching the rear surfaces of the side frame 12s and the airbag 20. If this displacement is large, it is difficult to quickly transmit the load input to the force distribution cloth 30 as the bag expands to the burst line 40.

[0030] <<Embodiment 2>> Next, referring to FIGS. 7 and 8, Embodiment 2 in which a sewing portion 70 composed of a seam 71 is provided on the outer force distribution cloth 31 will be described. Embodiment 2 has the same configuration as Embodiment 1 except that the outer force distribution cloth 31 has a sewing portion 70. The following description will mainly focus on the differences from Embodiment 1, and the description of the common points will be omitted.

[0031] A sewing portion 70 composed of a pair of two seams 71 is provided on the fan-shaped portion 31f of the outer force distribution cloth 31. In this example, a pair of sewing portions 70 is provided, but a plurality of pairs of sewing portions 70 may be provided.

[0032] The sewing part 70 reduces the stretchability of the outer force cloth 31. The outer force cloth 31 with reduced stretchability is more likely to transmit the load associated with the expansion of the bag than the force cloth 30 without the sewing part 70. Therefore, rapid breakage of the burst line 40 and rapid deployment of the bag can be achieved.

[0033] Each seam 71 of the sewing part 70 in this example extends such that the short edge 31S of the fan-shaped part 31f, that is, the rear of the fan-shaped part 31f, is spaced apart vertically, and the long edge 31L of the fan-shaped part 31f, that is, the front of the fan-shaped part 31f, is closer to each other. More specifically, the rear end of the upper seam 71 is located at the upper end of the short edge 31S of the fan-shaped part 31f, and the front end of the upper seam 71 is located at approximately the central part of the long edge 31L of the fan-shaped part 31f. On the other hand, the rear end of the lower seam 71 is located at the lower end of the short edge 31S of the fan-shaped part 31f, and the front end of the lower seam 71 is located at approximately the central part of the long edge 31L of the fan-shaped part 31f. Each seam 71 is linear. That is, the region surrounded by the short edge 31S of the fan-shaped part 31f, the long edge 31L of the fan-shaped part 31f, the upper seam 71, and the lower seam 71 is configured in a trapezoidal shape.

[0034] Each seam 71 of the sewing part 70 reduces the stretchability over a wide range of the outer force cloth 31 by being spaced apart vertically towards the rear of the fan-shaped part 31f. On the other hand, each seam of the sewing part 70 is closer to each other towards the front of the fan-shaped part 31f, making it easier to intensively transmit the load input to the force cloth 30 to a specific region at the long edge 31L of the outer force cloth 31. This specific region is the region between the front ends of each seam 71 among the long edge 31L of the outer force cloth 31. That is, by providing the specific region to include the break start point 41 of the burst line 40, the burst line 40 can be appropriately broken so as to spread vertically from the break start point 41.

[0035] In this example, since the shortening part 32s is provided on the inner force cloth 32 and the sewing part 70 is provided on the outer force cloth 31, the load associated with the expansion of the bag can be quickly transmitted from either of the two force cloths 30 to the burst line 40. In particular, when viewing the seat back 12 from the side of the vehicle, it is preferable to provide at least one of the shortening part 32s and the specific area so as to intersect a line segment 100 passing through the center of the lower curved part 12bc among the extension lines of the diameters forming the arc of the lower curved part 12bc. In this example, the center of the lower curved part 12bc and the break start point 41 of the burst line 40 are provided at substantially the same vertical positions along the axis of the force cloth 30. In other words, the center part of the lower curved part 12bc, the shortening part 32s, and the break start point 41 of the burst line 40 are all located on the line segment 100.

[0036] When the center part of the lower curved part 12bc and the break start point 41 of the burst line 40 are vertically displaced along the axis of the force cloth 30, it is preferable to provide the shortening part 32s at a position including the center of the lower curved part 12bc and provide the specific area of the outer force cloth 31 so as to include the break start point 41.

[0037] The present invention is not limited to these examples, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0038] In Embodiments 1 and 2, as the shortening part 32s, a configuration in which the force cloth 30 is partially folded and sewn is shown, but other configurations may also be used. For example, the force cloth 30 may be partially folded and held in the folded state with an adhesive. Additionally, the edge where the force cloth 30 is sewn to the tape 51 of the fastener 50 may be cut in a curved shape. In that case, the curved edge of the force cloth 30 and the tape 51 of the fastener 50 configured in a linear shape may be sewn in a curved shape along the edge of the force cloth 30. In any case, it is only necessary that the perimeter of the part of the force cloth 30 in the vicinity of the fastener 50 corresponding to the curved part of the side frame 12s is locally reduced.

[0039] In addition, the force cloth structure of the present invention can also be applied to the airbag of the seat cushion. For example, the force cloth cylindrically covers the side frame of the seat cushion and the seat cushion airbag fixed to the side frame. The side frame is also provided with a curved portion. This curved portion protrudes upward, for example. Also in this case, similar to Embodiment 1 and Embodiment 2, a shortened portion where the perimeter of the force cloth is locally reduced may be provided in the vicinity of the fastener that covers the curved portion. Furthermore, even when a seat cushion airbag is provided on the front frame of the seat cushion, the force cloth structure of the present invention can be similarly applied.

Explanation of Signs

[0040] 1 Seat 11 Seat Cushion 12 Seat Back 12f Seat Back Frame 12s Side Frame 12tc Upper Curved Portion 12bc Lower Curved Portion 13 Headrest 14 Seat Cover 14s Side Cover 14r Rear Cover 14m Main Cover 15 Side Support 15c Side Support Cover 16 Pad 20 Airbag 30 Force Cloth 31 Outer Force Cloth 31r Rectangular Portion 31f Sector Portion 31L Long Edge 31S Short Edge 31m Mountain Fold Line 31fe First Edge 31se Second Edge 32 Inner Force Cloth 32r Rectangular Portion 32t T-shaped Portion 32L Long Edge 32S Short Edge 32m Mountain Fold Line 32fe First edge 32se Second edge 32s Shrinkage part 40 Burst line 41 Breaking start point 50 Fastener 51 Tape 52 Element group 53 Slider 60 Gap 70 Sewing part 71 Stitch 100 Line segment

Claims

Claim 1 A set of force fabrics that cylindrically cover a frame and an airbag provided on a vehicle seat, A burst line formed by sewing together first edges of the force fabrics and a cover of the seat, A fastener that connects second edges of the force fabrics, and comprising, The frame has a curved portion that protrudes toward the burst line, The force fabric has a shortened portion that locally reduces the perimeter of the force fabric in the vicinity of the fastener that covers the curved portion, Force fabric structure.

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