Airbag

Abstract: An airbag is provided which is easy to be sewn up and which is capable of providing a large extent of thickness when inflated comprises two pieces of panels (A,B). The panels (A,B) are superposed on each other and sewn by a seam along sides (1,2,3,11,12,13) so as to make an envelope. Sides (4a,4b) are sewn by a seam (30). Other open edges than the sewn edges of the envelope are sequentially sewn by seams (40,50,60).

Description: BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT The present invention relates to an airbag of an airbag apparatus which is installed in a vehicle including an automobile and, more particularly, relates to an airbag which is preferable for a passenger's seat. A conventional airbag having a drum shape for a front passenger's seat consists of three panels. Another airbag consisting of two panels is also known. The former comprises three panels which are a pair of end panels and one drum panel. The end panels constitute portions corresponding to both drum head-ends of a drum shape and the drum panel constitutes a portion corresponding to a body-shell of the drum shape. Although this airbag provides a large extent of thickness (the length along a direction from a vehicle occupant to an instrument panel) when inflated, it takes long time to sew up the airbag because it is sewn in three dimensions. On the other hand, the airbag comprising two panels which are sewn to each other along their peripheries can be easily sewn because it is sewn in two dimensions, but provides a less extent of airbag thickness when inflated. In JP 1 029 485 A an airbag according to the preambles of claims 1 and 2 is disclosed. OBJECT AND SUMMARY OF THE INVENTION It is an object of the present invention to provide an airbag which can be easily sewn and is capable of providing a large extent of thickness when inflated. An airbag of a first aspect of the present invention comprises two schematically trapezoidal panels A and B which are sewn together. The panel A includes a side 2 corresponding to a top of a trapezoid, a side 4 corresponding to the base of the trapezoid, and sides 1 and 3 corresponding to the oblique sides of the trapezoid, and has a rectangular recess 5 formed in the middle of the side 4 and protrusions 6a, 6b protruding from portions of the sides 1, 3 near the side 4. The panel B includes a side 12 corresponding to the top of the trapezoid, a side 14 corresponding to the base of the trapezoid, and sides 11, 13 corresponding to the oblique sides of the trapezoid, and a rectangular protrusion 15 protruding from the middle of the side 14. The protrusions 6a, 6b have lateral sides 7a, 7b continuously connected to the sides 1, 3. The side 4 of the panel A has sides 4a, 4b on both sides of the rectangular recess 5. The rectangular recess 5 has sides 51, 53 continuously connected to the sides 4a, 4b, and a side 52 connecting the sides 51 and 53. The side 14 of the panel B has sides 14a, 14b between the both lateral sides 15a, 15b of the protrusion 15 and the sides 11, 13, respectively. The panels A, B are sewn together along the sides 1, 11, along the sides 2, 12, and along the sides 3, 13 by a seam 20. Portions along the sides 4a, 4b of the panel A are sewn to each other by a seam 30 and edges of the protrusions 6a, 6b of the panel A and an edge of the protrusion 15 of the panel B are sewn to each other by a seam 40. Portions along the side 7a of the panel A and the side 15a and a portion along the side 14a of the panel B are sewn to each other by a seam 50 and portions along the side 7b of the panel A and the side 15b and a portion along the side 14b of the panel B are sewn to each other by a seam 50. Portions along the sides 51, 53 and a portion along the side 52 of the rectangular recess 5 of the panel A are sewn to each other by a seam 60. The following process can be taken as an example to sew up the airbag of the first aspect. The panels A, B are superposed on each other and then sewn together along the sides 1, 2, 3, 11, 12, and 13 by the seam 20 so as to make an envelope body. The envelope body is reversed inside out. The sides 4a, 4b of the panel A are superposed on each other and portions along the sides 4a, 4b of the panel A are sewn to each other by the seam 30. The protrusions 6a, 6b of the panel A are superposed on the protrusion 15 of the panel B and are sewn up by the seam 40. After the sides 7a, 15a are straightened, they are superposed on the side 14a of the panel B and sewn by the seam 50. After the sides 7b, 15b are straightened, they are superposed on the side 14b of the panel B and sewn by the seam 50. The sides 51, 53 of the rectangular recess 5 of the panel A are straightened and they are superposed on the side 52 and sewn by the seam 60. It should be noted that the aforementioned sewing process is just an example and modifications can be taken. The envelope body may not be reversed inside out. An airbag of a second aspect of the present invention comprises two schematically trapezoidal panels A' and B which are sewn together. The panel A' includes a side 2 corresponding to a top of a trapezoid, a side 4 corresponding to the base of the trapezoid, and sides 1 and 3 corresponding to the oblique sides of the trapezoid, and has a rectangular recess 5 formed in the middle of the side 4. The panel B includes a side 12 corresponding to the top of the trapezoid, a side 14 corresponding to the base of the trapezoid, and sides 11, 13 corresponding to the oblique sides of the trapezoid, and a rectangular protrusion 15 protruding from the middle of the side 14. The protrusion 15 has sides 15a, 15b continuously connected to the side 14 and a side 15c connecting the sides 15a and 15b. The side 1 of the panel A' consists of a side 1f superposed on the side 11 of the panel B and a side 1r lengthened from the side 1f. The side 3 of the panel A' consists of a side 3f superposed on the side 13 of the panel B and a side 3r lengthened from the side 3f. The side 4 of the panel A' has sides 4a, 4b on both sides of the rectangular recess 5. The rectangular recess 5 has sides 51, 53 continuously connected to the sides 4a, 4b, and a side 52 connecting the sides 51 and 53. The side 14 of the panel B has sides 14a, 14b between the both lateral sides 15a, 15b of the protrusion 15 and the sides 11, 13, respectively. The panels A', B are sewn together along the sides 1f, 11, along the sides 2, 12, and along the sides 3f, 13 by a seam 20. Portions along the sides 4a, 4b of the panel A' are sewn to each other by a seam 30 and a portion along the side 15a of the panel A' and a portion along the side 14a of the panel B are sewn to each other by a seam 58. A portion along the side 15b of the panel A' and a portion along the side 14b of the panel B are sewn to each other by a seam 58 and portions along the sides 1r, 3r of the panel A' and a portion along the side 15c of the panel B are sewn to each other by a seam 48. Portions along the sides 51, 53 and a portion along the side 52 of the rectangular recess 5 of the panel A' are sewn to each other by a seam 60. The following process can be taken as an example to sew up the airbag of the second aspect. The panels A', B are superposed on each other and then sewn together along the sides 1f, 2, 3f, 11, 12, and 13 by the seam 20 so as to make an envelope body. The sides 4a, 4b of the panel A' are superposed on each other and portions along the sides 4a, 4b of the panel A' are sewn to each other by the seam 30. The sides 1r, 3r of the panel A' are superposed on the side 15c of the protrusion 15 of the panel B and are sewn up by the seam 48. The sides 14a and 15a of the panel B are superposed on each other and are sewn up by the seam 58. The sides 14b and 15b of the panel B are superposed on each other and sewn up by the seam 58. The sides 51, 53 of the rectangular recess 5 of the panel A' are straightened and they are superposed on the side 52 and sewn by the seam 60. It should be noted that the aforementioned sewing process is just an example and modifications can be taken. BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1a through 1f are views illustrating a process of sewing an airbag according to a first embodiment; Figs. 2a through 2f are views illustrating the process of sewing the airbag according to the first embodiment; Fig. 3 is a view illustrating the process of sewing the airbag according to the first embodiment; Fig. 4 is a view illustrating the process of sewing the airbag according to the first embodiment; Fig. 5 is a view illustrating the process of sewing the airbag according to the first embodiment; Fig. 6 is a view illustrating the process of sewing the airbag according to the first embodiment; Figs. 7a through 7c are views illustrating the process of sewing the airbag according to the first embodiment; Figs. 8a and 8b are views illustrating the process of sewing the airbag according to the first embodiment; Fig. 9 is a perspective view of the sewn airbag; Fig. 10 is a perspective view of the sewn airbag; Figs. 11a through 11d are views illustrating a process of sewing an airbag according to a second embodiment; Figs. 12a through 12f are views illustrating the process of sewing the airbag according to the second embodiment; Fig. 13 is a view illustrating the process of sewing the airbag according to the second embodiment; Fig. 14 is a view illustrating the process of sewing the airbag according to the second embodiment; Fig. 15 is a view illustrating the process of sewing the airbag according to the second embodiment; Fig. 16 is a view illustrating the process of sewing the airbag according to the second embodiment; Figs. 17a and 17b are views illustrating the process of sewing the airbag according to the second embodiment; Fig. 18 is a perspective view of the sewn airbag according to the second embodiment; and Fig. 19 is a perspective view of a sewn airbag according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an airbag of the first aspect of the present invention will be described with reference to Figs. 1 through 10. Two panels A and B are cut out of a foundation cloth. The panels A and B are superposed on each other, as shown in Figs. 1a and 1b. The panel A is formed in a schematically trapezoidal configuration having four sides 1, 2, 3, and 4. The side 4 corresponding to the base of the trapezoid is formed in a V-like configuration and is provided with a rectangular recess 5 in the middle thereof. The side 4 of the panel A includes sides 4a, 4b on both sides of the rectangular recess 5. The rectangular recess 5 includes sides 51, 53 continuously connected to the sides 4a, 4b and also includes a side 52 connecting the sides 51, 53. As for the sides 1, 3 corresponding to the oblique sides of the trapezoid, protrusions 6a, 6b protrude from portions of the sides 1, 3 near the side 4, respectively. Numerals 7a, 7b designate lateral sides of these protrusions 6a, 6b. These sides 7a, 7b continuously connected to the sides 1, 3. The side 2 is positioned to correspond to the top of the trapezoid. The panel A is provided with a gas inlet 9 formed therein. The panel B is formed in a schematically trapezoidal configuration having four sides 11,12, 13, and 14. The side 14 corresponding to the base of the trapezoid includes a protrusion 15 protruding therefrom. Numerals 15a, 15b designate lateral sides continuously connected to the side 14 of the protrusion 15. A side 15c lies and elongates between the sides 15a and 15b. Numerals 14a, 14b designate portions of the side 14 positioned on both sides of the protrusion 15. After superposing these panels A, B on each other along the sides 1 and 11, the sides 2 and 12, and the sides 3 and 13 each to each, the panels A, B are sewn up along the sides 1, 2, 3 and 11, 12, 13, as shown in Figs. 1c and 1d. A numeral 20 designates a seam of the sewing. Fig. 1d is a sectional view taken along a line D-D in Fig. 1c. As shown in Figs. 1e and 1f, a sewn envelope body which is made by sewing up the panels A, B as mentioned above is reversed inside out so that the inner surface of the body becomes the outer surface thereof. Accordingly, the seam 20 is hidden inside the envelope. Fig. 1f is a sectional view taken along a line F-F in Fig. 1e. Then, the panels A ,B of this sewn body are pulled in the direction of arrows G, G in Fig. 1f. Accordingly, the panel A is folded in two along the center line g thereof in Fig. 1e, and the sides 4a, 4b are superposed on each other as shown in Fig. 2a and Fig. 3. The panel B is also folded in two in the same manner along the center line g thereof. Accordingly, the protrusion 15 is also folded in two so that the sides 15a, 15b are superposed on each other and the sides 14a, 14b are also superposed on each other. In this state, portions along the sides 4a, 4b of the panel A are sewn to each other as shown in Fig. 2b and Fig. 4. A numeral 30 designates a seam along the sides 4a, 4b. Figs. 2c and 2d are a sectional view taken along a line C-C and a view taken along a line D-D, respectively. As shown in Fig. 2c, a sewn portion 21 by the seam 20 is disposed inside the sewn body. After that, the panels A, B of this sewn envelope body are pulled in the direction of arrows E, E in Fig. 2d. After the body becomes in a state shown in Fig. 2e, it is further pulled in the direction of arrows F, F in Fig. 2e so as to become in the state shown in Fig. 2f and Fig. 5. Referring to Fig. 2f and Fig. 5, the protrusions 6a, 6b are superposed on the protrusion 15 so that the side 7a and the side 15a, the side 7b and the side 15b are also superposed on each to each. Each side 14a, 14b is in the state folded in two. The sewn portion 21 by the seam 20 is positioned on a line extending from the sides 7a, 7b. In the state shown in Fig. 2f and Fig. 5, the protrusions 6a, 6b are sewn to the protrusion 15 along their edges,. A numeral 40 designates a seam of the sewing. Fig. 7a is an enlarged view of a portion VII in Fig. 6. Then, the sewn portion 21 and a portion 42 of the panel B which confronts the sewn portion 21 are pulled in the direction of arrows VII B , VII B in Fig. 7a. Accordingly, as shown in Fig. 7b, the side 14a is straightened and the sides 7a, 15a are also straightened whereby the sides 7a, 15a are superposed on the side 14a. Then, the panels are sewn along the side 14a and the sides 7a, 15a as shown in Fig. 7c. A numeral 50 designates a seam of this sewing. Though it is not shown, the sides 7b, 15b, and 14b on the right-hand side of Fig. 6 are also sewn in the same manner. In the state just after sewing by the seam 50, the sides 51, 53 of the rectangular recess 5 are superposed on each other and the side 52 is folded in two as shown in Fig. 8a which is an enlarged view of a portion VIII in Fig. 6. Left and right corners 5L, 5R where the sides 51, 53 intersect the side 52, respectively are pulled in the direction of arrows VIII B , VIII B . Accordingly, as shown in Fig. 8 b, the side 52 is straightened and the sides 51, 53 are also straightened. Then, the panel A is sewn along these sides 51, 52 and 53. A numeral 60 designates a seam of the sewing. In this way, an airbag 70 is completed as shown in Fig. 9. Because this airbag 70 comprises only two pieces of panels A, B, and each of the sewn portions can be finished by the straight stitches, sewing work is easy. This airbag 70 provides a large extent of thickness when inflated, such as obviously shown in Fig. 9. Although the inlet 9 for introducing gas is provided in this embodiment mentioned above, a pair of parallel slits 9a, 9b may be provided as shown in Fig. 10. By inserting a rod-shaped inflator in these slits 9a, 9b, the airbag can be connected to the inflator. Hereinafter, embodiments of an airbag of the second aspect of the present invention will be described with reference to Figs. 11 through 19. A panel A' used in this embodiment has the same shape as the panel A of the first embodiment except that the protrusions 6a, 6b are not provided thereto. The sides 1, 3 consist of front sides 1f, 3f and rear sides 1r, 3r respectively. The sides 1f, 3fhave almost the same length as the sides 11, 13. The other constituents of the panel A' are identical to those of the panel A mentioned above and the same numeral corresponds to the same portion. A panel B appearing in this embodiment is completely the same as the panel B of the above embodiment. After superposing these panels A', B on each other along the sides 1f and 11, the sides 2 and 12, and the sides 3f and 13 each to each, the panels A', B are sewn up along the sides 1, 2, 3 and 11, 12, 13, as shown in Figs. 11c and 11d. A numeral 20 designates a seam of the sewing. The sides 1r, 3r projecting from the sides 11, 13 are not sewn on the sides 11, 13. Fig. 11d is a sectional view taken along a line D-D in Fig. 11c. Then, the panels A', B of this sewn body are pulled in the direction of arrows G, G in Fig. 11d. Accordingly, the panel A' is folded in two along the center line g thereof in Fig. 11e, and the sides 4a, 4b are superposed on each other as shown in Fig. 12a and Fig. 13. The panel B is also folded in two in the same manner along the center line g thereof. Accordingly, the protrusion 15 is also folded in two so that the sides 15a, 15b are superposed on each other and the sides 14a, 14b are also superposed on each other. In this state, portions along the sides 4a, 4b of the panel A' are sewn to each other as shown in Fig. 12b and Fig. 14. A numeral 30 designates a seam along the sides 4a, 4b. Figs. 12c and 12d are sectional views taken along a line C-C and a view taken along a line D-D, respectively. As shown in Fig. 12c, a sewn portion 21 by the seam 20 is disposed outside the sewn body. After that, the panels A', B of this sewn envelope body are pulled in the direction of arrows E, E in Fig. 12d. After the body becomes in a state shown in Fig. 12e, it is further pulled in the direction of arrows F, F in Fig. 12e so as to become in the state shown in Fig. 12f and Fig. 15. As a result thereof, the sides 1r and 3r become linear in a straight line. Then the side 15c of the protrusion 15 is sewn to the sides 1r, 3r of the panel A' by the seam 48 and the sides 15a and 14a are sewn to each other, and the sides 15b and 14b are sewn to each other by the seam 58, respectively. After that, the left and right corners 5L, 5R where the sides 51, 53 of the rectangular recess 5 intersect the side 52, respectively are pulled in the direction of arrows VIII B , VIII B in such a manner as the former embodiment as shown in Fig. 17a. Then, the panel A' is sewn along these sides 51, 52 and 53 as shown in Fig 17b. The numeral 60 designates the seam of the sewing. In this way, an airbag is completed as shown in Fig. 18. Because this airbag comprises only two pieces of panels A', B, and each of the sewn portions can be finished by the straight stitches, sewing work is easy. This airbag provides a large extent of thickness when inflated, such as obviously shown in Fig. 18. In stead of the inlet 9, a pair of parallel slits 9a, 9b may be provided as shown in Fig. 19. By inserting a rod-shaped inflator in these slits 9a, 9b, the airbag can be connected to the inflator. While the sewing process of this embodiment mentioned above is an example of producing the airbag of the present invention, other sewing process than the above may be employed in the present invention. The airbag of the present invention is not only easy to be sewn, but also capable of providing a large extent of thickness when inflated, as mentioned above.

Claims: An airbag comprising a schematically trapezoidal first panel (A) and a schematically trapezoidal second panel (B) which are sewn together, said first panel (A) including a first side (2) corresponding to the top of the trapezoid, a second side (4) corresponding to the base of the trapezoid, and third and fourth sides (1, 3) corresponding to the oblique sides of the trapezoid, said second panel (B) including a first side (12) corresponding to an upper side of the trapezoid, a second side (14) corresponding to the base of the trapezoid, and third and fourth sides (11, 13) corresponding to the oblique sides of the trapezoid, said first and second panel (A, B) being sewn together along their respective third sides (1, 11), along their respective first sides (2, 12), and along their respective fourth sides (3, 13) by a seam (20), characterized in said first panel (A) having a rectangular recess (5) formed in the middle of its second side (4) and first and second protrusions (6a, 6b) protruding from the portions of its third and fourth sides (1, 3) near its second side (4), said second panel (B) having a third protrusion (15) protruding from the middle of its second side (14), said first and second protrusions (6a, 6b) of said first panel (A) having first and second lateral sides (7a, 7b) continuously connected to the third and fourth sides (1, 3) of said first panel (A), said second side (4) of said first panel (A) having fifth and sixth sides (4a, 4b) on both sides of the rectangular recess (5), said rectangular recess (5) having seventh and eighth sides (51, 53) continuously connected to said fifth and sixth sides (4a, 4b) and a ninth side (52) connecting said seventh and eighth sides (51, 53), said second side (14) of said second panel (B) having tenth and eleventh sides (14a, 14b) between both third and fourth lateral sides (15a, 15b) of the third protrusion (15) and the third and fourth sides (11, 13) of said second panel (B), respectively, portions along the fifth and sixth sides (4a, 4b) of said first panel (A) being sewn to each other by a seam (30), edges of the first and second protrusions (6a, 6b) of said first panel (A) and an edge of the third protrusion (15) of said second panel (B) being sewn to each other by a seam (40), portions along the first lateral side (7a) of said first panel (A) and the third lateral side (15a) and a portion along the tenth side (14a) of said second panel (B) being sewn to each other by a seam (50), portions along the second lateral side (7b) of said first panel (A) and the fourth lateral side (15b) and a portion along the eleventh side (14b) of said second panel (B) being sewn to each other by a seam (50), and portions along the seventh and eighth sides (51, 53) and a portion along the ninth side (52) of the rectangular recess (5) of said first panel (A) being sewn to each other by a seam (60). An airbag comprising a schematically trapezoidal first panel (A') and a schematically trapezoidal second panel (B) which are sewn together, said first panel (A') including a first side (2) corresponding to the top of the trapezoid, a second side (4) corresponding to the base of the trapezoid, and third and fourth sides (1, 3) corresponding to the oblique sides of the trapezoid, said second panel (B) including a first side (12) corresponding to an upper side of the trapezoid, a second side (14) corresponding to the base of the trapezoid, and third and fourth sides (11, 13) corresponding to the oblique sides of the trapezoid, characterized in said first panel (A') having a rectangular recess (5) formed in the middle of its second side (4), said second panel (B) having a protrusion (15) protruding from the middle of its second side (14), said protrusion (15) having fifth and sixth sides (15a, 15b) continuously connected to said second side (14) of said second panel (B) and a seventh side (15c) connecting said fifth and sixth sides (15a, 15b), the third side (1) of the first panel (A') consisting of an eighth side (1f) superposed on the third side (11) of the second panel (B) and a ninth side (1r) lengthened from said eighth side (1f), the fourth side (3) of the first panel (A') consisting of a tenth side (3f) superposed on the fourth side (13) of the second panel (B) and an eleventh side (3r) lengthened from said tenth side (3f), said second side (4) of said first panel (A') having twelfth and thirteenth sides (4a, 4b) on both sides of the rectangular recess (5), said rectangular recess (5) having fourteenth and fifteenth sides (51, 53) continuously connected to said twelfth and thirteenth sides (4a, 4b) and a sixteenth side (52) connecting said fourteenth and fifteenth sides (51, 53), said second side (14) of said second panel (B) having seventeenth and eighteenth sides (14a, 14b) between both fifth and sixth sides (15a, 15b) of the protrusion (15) and the third and fourth sides (11, 13) of said second panel (B), respectively, said first and second panels (A', B) being sewn together along the eighth side (1f) and the third side (11) of said second panel (B), along their respective second sides (2, 12) and along the tenth side (3f) and the fourth side (13) of said second panel (B) by a seam (20), portions along the twelfth and thirteenth sides (4a, 4b) of said first panel (A') being sewn to each other by a seam (30), a portion along the fifth side (15a) of said first panel (A') and a portion along the seventeenth side (14a) of said second panel (B) being sewn to each other by a seam (58), a portion along the sixth side (15b) of said first panel (A') and a portion along the eighteenth side (14b) of said second panel (B) being sewn to each other by a seam (58), portions along the ninth and eleventh sides (1r, 3r) of said first panel (A') and a portion along the seventh side (15c) of said second panel (B) being sewn to each other by a seam (48), and portions along the fourteenth and fifteenth sides (51, 53) and a portion along the sixteenth side (52) of the rectangular recess (5) of said first panel (A') being sewn to each other by a seam (60). The airbag as claimed in claim 1 or 2, wherein an opening for introducing the gas therethrough or a pair of slits for inserting an inflator therethrough are disposed in the vicinity of the rectangular recess (5) of the first panel (A; A'). The airbag as claimed in any one of claims 1 through 3, wherein said airbag is for a passenger's seat.

Inventors: AMAMORI ICHIRO, AMAMORI, ICHIRO
Applicants: TAKATA CORP, TAKATA CORPORATION
Application year: 1999
Main classification: B60R21
IPC codes: B60R21