Source: https://patents.com/us-7481456.html
Timestamp: 2019-10-22 03:21:25
Document Index: 288546097

Matched Legal Cases: ['art 51', 'arts 52', 'arts 39', 'arts 52', 'art 51', 'arts 52', 'art 54', 'art 54', 'arts 39', 'arts 39', 'art 54', 'art 38', 'arts 39', 'art 54', 'arts 52', 'arts 39', 'art 51', 'arts 39', 'arts 39', 'arts 52', 'art 51', 'arts 39', 'art 39']

US Patent # 7,481,456. Airbag apparatus - Patents.com
United States Patent 7,481,456
Nozaki , et al. January 27, 2009
Inventors: Nozaki; Hiroyuki (Utsunomiya, JP), Nagai; Makoto (Sakura, JP), Chida; Yusuke (Utsunomiya, JP)
Appl. No.: 12/134,655
Jun 11, 2007 [JP] 2007-154017
Current U.S. Class: 280/743.1 ; 280/731
Field of Search: 280/731,743.1
5470160 November 1995 Nowlin
5511821 April 1996 Meyer et al.
5599040 February 1997 Takahashi et al.
5899495 May 1999 Yamamoto et al.
6209912 April 2001 Staub et al.
6352283 March 2002 Ellerbrok et al.
6634670 October 2003 Ellerbrok et al.
7401811 July 2008 Nagai et al.
2005/0098991 May 2005 Nagai et al.
2007/0241546 October 2007 Chida et al.
2006-224748 Aug., 2006 JP
1. An airbag apparatus comprising: an airbag having at least a pair of base fabric pieces, at least one of which having a center part from which high-pressure gas is introduced into an internal space enclosed by the pair of the base fabric pieces, thereby expanding the airbag; a vent hole which discharges internal gas of the airbag; a plurality of rupture joining parts each having a starting-end and a finishing-end, the finishing-end provided at an outer position of the airbag than the starting-end, the plurality of rupture joining parts joining the base fabric pieces in a manner breakable by the high-pressure gas expansion; and a vent hole cover having a connecting part at which the vent hole cover is connected to the airbag by the rupture joining parts, wherein: the airbag has an outer expansion part provided at a position outside the finishing-ends of the rupture joining parts; the plurality of rupture joining parts are rotationally symmetric to each other about the center of the base fabric pieces, and partially overlap each other in the circumferential direction; and the connecting part of the vent hole cover is provided in the vicinity of a middle position of the two finishing-ends of an adjacent pair of the rupture joining parts.
2. The airbag apparatus according to the claim 1, wherein: the plurality of the rupture joining parts include a first rupture joining part and a second rupture joining part; and the starting-end of the first rupture joining part is provided in a vicinity of the finishing-end of the second rupture joining part, in a circumferential direction of the airbag.
3. The airbag apparatus according to the claim 1, wherein: the pair of the base fabric pieces are joined to each other at a peripheral joining part provided at a periphery part of the base fabric pieces; the periphery part of the base fabric pieces protrudes into the internal space enclosed by the pair of the base fabric pieces; the finishing-ends of the plurality of the rupture joining parts are provided separated in the radial direction of the base fabric pieces from the peripheral joining part; and the outer expansion part is provided between the peripheral joining part and the rupture joining part.
The second base fabric piece 37 is provided with: a circular inflator opening 37a which is connected to the inflator 31; and a circular vent hole 37b which ejects a part of the internal gas during the expansion of the airbag 32. The inflator opening 37a is provided at a center position of the second base fabric piece 37. The vent hole 37b is provided at a position apart from the center of the second base fabric piece 37. The inflator 31 generates high-pressure gas and supplies it into the airbag 32 through the inflator opening 37a at the center of the second base fabric piece 37.
At the inside of the airbag 32, a vent hole cover 50 is provided, which controls the internal gas pressure during the expansion. As shown in FIG. 2 and FIG. 3, the vent hole cover 50 is a belt-shaped sheet. The center part of the vent hole cover 50 in the longitudinal direction of the belt shape is the widest, with the width gradually decreasing toward both ends. The center part in the longitudinal direction of the vent hole cover 50 is a closing part 51 by which the vent hole 37b is covered up. Both ends in the longitudinal direction of the vent hole cover 50 are connecting parts 52, 53, which are sewn with the first and second base fabric pieces 36, 37 by the rupture joining parts 39A, 39B. While the vent hole cover 50 is sewn at the connecting parts 52, 53 with the airbag 32, the vent hole 37b is substantially closed by the closing part 51. The vent hole cover 50 releases the vent hole 37b wide open, when the connections at the connecting parts 52, 53 are ruptured.
The outer expansion part 54 expands its volume in the thickness direction when the high-pressure gas is introduced thereto. The inflator opening 37a from where the high-pressure gas is introduced, and the outer expansion part 54 are connected via narrow paths 55 (as shown in FIG. 3), each of which is surrounded by an adjacent pair of the rupture joining parts 39A, 39B, and 39C. Accordingly, until the rupture of the rupture joining parts 39A, 39B, and 39C proceeds to a point where the paths 55 become widely open, the high-pressure gas is not introduced at a substantial rate.
As shown in FIGS. 4 and 5, in this embodiment, the peripheral parts of the first base fabric piece 36 and the second base fabric piece 37 are folded, at the outer expansion part 54, pointing in an inside direction. The folded part is sewn at the peripheral joining part 38. Accordingly, the peripheral parts of the first base fabric piece 36 and the second base fabric piece 37 are further expandable in the thickness direction as compared to the expansion at the central part of the airbag 32. Accordingly, as described earlier, when the high-pressure gas is introduced into the airbag 32 from the inflator opening 37a, and the rupture of the rupture joining parts 39A, 39B, and 39C proceeds, thereby widely opening the path 55, the expansion of the airbag 32 at the outer expansion part 54 is initiated.
In the early phase of the airbag 32 development, the connecting parts 52, 53 of the vent hole cover 50 are sewn to the first and second base fabric pieces 36, 37 by the rupture joining parts 39A, 39B, and 39C. Accordingly, as shown in FIG. 9, the vent hole 37b is closed by the closing part 51 of the vent hole cover 50. Thereby, gas leakage from the airbag 32 is prevented. Accordingly, at this time, the internal air pressure of the airbag 32 rises rapidly, and the development of the airbag 32 is performed rapidly.
As the airbag 32 develops the rupture positions of the rupture joining parts 39A, 39B, and 39C reach a predetermined point close to the finishing-end 26. At this time, by a further rupture of the rupture joining parts 39A, 39B, the grip of the connecting parts 52, 53 of the vent hole cover 50 is released. As a result, as shown in FIG. 10, the closing part 51 of the vent hole cover 50 is pushed out of the vent hole 37b. Thereby, the blocking of the vent hole 37b by the vent hole cover 50 is released. Accordingly, excess gas in the airbag 32 is discharged through the vent hole 37b, and an excessive increase of the internal air pressure in the airbag 32 is prevented. Thereafter, as a result of the gas pressure discharge from the vent hole 37b and the further rupture progress of the rupture joining parts 39A, 39B, and 39C, the development behavior of the airbag 32 is controlled as desired.
Accordingly, in the airbag apparatus 13, even when the rupture of the rupture joining part 39A is interrupted for some reason, the vent hole 37b can be released at substantially the same timing as the release timing when the rupture interruption does not occur.
Previous Patent US 7,481,455 | Next Patent US 7,481,457