Abstract:
An airbag includes a bag body and a buffering pad. The bag body includes a cushioning surface and an opposite back surface, which together define an air chamber between them. The cushioning surface and the back surface are partially sawed and clinched in certain pattern. The air chamber of the bag body is provided with an air inlet. The buffering pad is partially connected to the periphery of the cushioning surface side of the bag body. The size of the buffering pad is smaller than that of the cushioning surface. While the airbag is inflated, the bag body is deployed at a limited thickness due to the clinched sawing and also pulled by the smaller sized buffering pad into an arch formed air shield. At the same time a buffering space is formed between the buffering pad and the cushioning surface.

Description:
RELATED APPLICATIONS 
     This application claims priority to Taiwanese Application Serial Number 103119084, filed May 30, 2014, which is herein incorporated by reference. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an airbag, and more particularly, to an airbag with multiple layers of progressive cushioning effect. 
     2. Description of Related Art 
     In recent years, owing to the raising of vehicle safety awareness, vehicles are equipped with several airbags for protecting occupants during car collisions. 
     An airbag generally includes a folded bag body, which can be used together with an inflating module (including sensors, a collision sensor, and an inflator). The principle of the airbag is to sense the collision of a vehicle by using several sensors or a single-point sensor disposed in the vehicle and to determine whether using the collision sensor should deploy the bag body. That is, when a car collision occurs, the sensor(s) will sense the instant acceleration of the collision, and the collision sensor determines whether the instant acceleration exceeds a predetermined threshold. If the instant acceleration exceeds the predetermined threshold, the collision sensor will transmit a signal to an igniter to initiate the inflator to produce large amounts of gas into the bag body. Meanwhile, the bag body is instantly expanded. When the car collision occurs, the driver and the front passenger (hereinafter referred to occupants) will firstly contact the inflated airbags rather than directly impact the steering wheel or the dashboard with their heads or chests, so as to achieve the purpose of protecting the occupants. 
     Various kinds of airbags have been developed, such as the airbags deployed from the steering wheels, the airbags deployed from the dashboards, the airbags deployed from the side windows, the airbags deployed from the seat belt buckles, and the airbags deployed from the headrests of the seats. The different kinds of airbags are expected to cope with different kinds of car collisions respectively. Each of the different kinds of airbags is nothing more than providing an inflated bag body for occupants to firstly contact, so as to buffer the occupants from other hard objects in the vehicles. 
     When the bag body of an airbag is instantly inflated to full deployment, the saturation pressure of the gas in the bag body makes the bag body relatively hard. A conventional airbag is a simple structure having a single bag body, so when a car collision occurs, an occupant will directly contact the hard bag body and thus injure the contacting portions of the body of the occupant. 
     SUMMARY 
     In order to solve the foregoing problem, the disclosure provides an airbag with multiple layers of progressive cushioning effect to prevent an occupant from directly contacting a hard bag body of the airbag. 
     According to an embodiment, the disclosure provides an airbag with multiple layers of progressive cushioning effect. The airbag includes a bag body and a buffering pad. The bag body includes a cushioning surface and an opposite back surface. An air chamber is defined between the cushioning surface and the opposite back surface. A plurality of sealing portions are separately disposed between the cushioning surface and the opposite back surface. Portions other than the sealing portions between the cushioning surface and the opposite back surface are communication portions. The air chamber has an air inlet. A part of a periphery of the buffering pad is connected to a periphery of the bag body. The buffering pad is located on a side of the bag body proximal to the cushioning surface. The area of the buffering pad is smaller than the area of the cushioning surface. While the airbag is inflated, the bag body is restrained by the sealing portions, so that the bag body is inflated to be into an arch-shaped air shield with a limited thickness, the bag body and the buffering pad pull each other to form an arch-shaped housing, and a buffering space is formed between the buffering pad and the cushioning surface. Consequently, the buffering pad, the buffering space, and the inflated bag body provide multiple layers of progressive cushioning effect, thus the airbag can offer a progressive pressure relieving cushioning effect rather than a directly hard bumping toward the occupant during a car collision. 
     According to another embodiment, the disclosure provides an airbag with multiple layers of progressive cushioning effect. The airbag includes a bag body and a buffering pad. The bag body includes a cushioning surface and an opposite back surface. An air chamber is defined between the cushioning surface and the opposite back surface. A plurality of straight groups of sealing portions are separately disposed between the cushioning surface and the opposite back surface. Each of the straight groups of the sealing portions have a plurality of straightly arranged sealing portions. Portions other than the sealing portions between the cushioning surface and the opposite back surface are communication portions. The air chamber has an air inlet. Two side peripheries and a plurality of portions at a center region of the buffering pad are respectively connected to two side peripheries and the straight groups of the sealing portions of the bag body. The buffering pad is located on a side of the bag body proximal to the cushioning surface. The area of the buffering pad is smaller than the area of the cushioning surface. While the airbag is inflated, the bag body and the buffering pad pull each other, so that the bag body is inflated to be an arch-shaped air shield with a limited thickness, and a plurality of buffering spaces are formed between the buffering pad and the cushioning surface. Consequently, the buffering pad, the buffering space, and the inflated bag body provide multiple layers of progressive cushioning effect, thus the airbag can offer a progressive pressure relieving cushioning effect rather than a directly hard bumping toward the occupant during a car collision. 
     It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the disclosure as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1  is a perspective view of an airbag with multiple layers of progressive cushioning effect according to a first embodiment of the disclosure, in which the airbag is fully inflated; 
         FIG. 2  is an exploded view of the airbag in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of the airbag in  FIG. 1  along line A-A; 
         FIG. 4  is a cross-sectional view of the airbag in  FIG. 1  along line B-B; 
         FIG. 5  is a perspective view of an airbag with multiple layers of progressive cushioning effect according to a first example of the first embodiment of the disclosure, in which the airbag is installed on a seat belt and is fully inflated; 
         FIG. 6A  is a cross-sectional view of the airbag in  FIG. 5 ; 
         FIG. 6B  is a cross-sectional view of the airbag in  FIG. 6A  encountering with an occupant; 
         FIG. 7  is a perspective view of an airbag with multiple layers of progressive cushioning effect according to a second example of the first embodiment of the disclosure, in which the airbag is disposed on a steering wheel and is fully inflated; 
         FIG. 8A  is a cross-sectional view of the airbag in  FIG. 7 ; 
         FIG. 8B  is a cross-sectional view of the airbag in  FIG. 8A  encountering with an occupant; and 
         FIG. 9  is a perspective view of an airbag with multiple layers of progressive cushioning effect according to a second embodiment of the disclosure, in which the airbag is installed in a headrest of a seat and is fully inflated. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     Referring to  FIG. 1  to  FIG. 4 , an airbag with multiple layers of progressive cushioning effect according to a first embodiment of the disclosure includes a bag body  100  and a buffering pad  300 . 
     In order to more clearly express the structure and features of the present disclosure, the bag body  100  is fully inflated. As shown in the figures, the bag body  100  includes a cushioning surface  110  and an opposite back surface  120 , and an air chamber  140  is defined between the cushioning surface  110  and the opposite back surface  120 . A plurality of sealing portions  130  are separately disposed between the cushioning surface  110  and the opposite back surface  120 . Portions other than the sealing portions  130  between the cushioning surface  110  and the opposite back surface  120  are communication portions  190 . Air in the air chamber  140  is communicated via the communication portions  190 . The arrangement of the sealing portions  130  can be a dotted layout, a linear layout, or a regional layout. As the example in the figures shows, the arrangement of the sealing portions  130  is a multi-zone layout. The air chamber  140  has an air inlet  180  and a plurality of vents  150 . The air inlet  180  can be connected to an external inflating module (not shown). When a car collision occurs, the inflating module can instantly inflate the air chamber  140  of the bag body  100  with air via the air inlet  180 . 
     The cushioning surface  110  and the opposite back surface  120  of the bag body  100  are sewn to be close to each other by a thread  160 , so as to form the sealing portions  130  between the cushioning surface  110  and the opposite back surface  120 . 
     The buffering pad  300  is made of a material having a good toughness, such as a fabric having a good toughness. The contour of the periphery of the buffering pad  300  substantially matches the contour of the periphery of the bag body  100 . The periphery of the buffering pad  300  is connected to the periphery of the bag body  100  with several connection portions  310 , and the buffering pad  300  is located on a side of the bag body  100  proximal to the cushioning surface  110 . The area of the buffering pad  300  is smaller than the area of the cushioning surface  110 , and a buffering space  170  is formed between the buffering pad  300  and the cushioning surface  110 . As the example in the figures shows, the periphery of the buffering pad  300  is connected to the periphery of the bag body  100  with four connection portions  310 . Each of other portions of the periphery of the buffering pad  300  forms an opening portion  320  communicated with the buffering space  170 , so as to relieve the compressing pressure. 
     While the airbag is fully inflated, owing to the sealing portions  130  separately disposed between the cushioning surface  110  and the opposite back surface  120 , the thickness of expansion between the cushioning surface  110  and the opposite back surface  120  of the bag body  100  is restrained at the sealing portions  130 , but the inflated air can still communicate in the air chamber  140  via the communication portions  190 . Hence, while the airbag is inflated, the cushioning surface  110  and the opposite back surface  120  of the bag body  100  are expanded outward, but the thickness of expansion of the portions at or adjacent to the sealing portions  130  are restrained without expanding. Moreover, while the airbag is fully inflated, the bag body  100  and the buffering pad  300  pull each other, so that the buffering pad  300  is expanded in a planar manner. Because the periphery of the bag body  100  is restrained by the periphery of the buffering pad  300  and the area of the buffering pad  300  is smaller than the area of the cushioning surface  110  of the bag body  100 , the buffering pad  300  will make the bag body  100  bulge toward the opposite back surface  120  and be in a form of arch-shaped air shield. Furthermore, the buffering space  170  is clearly formed between the cushioning surface  110  and the buffering pad  300 . Consequently, according to the airbag of the first embodiment of the disclosure, the buffering pad  300 , the buffering space  170 , and the bag body  100  provide multiple layers of progressive cushioning effect. 
     According to the first embodiment of the disclosure, the airbag can be installed at any appropriate location in the vehicle. For example, referring to  FIG. 5  to  FIG. 6B , an airbag with multiple layers of progressive cushioning effect according to a first example of the first embodiment of the disclosure is installed on a seat belt and is fully inflated. According to ergonomics, the airbag installed on the seat belt is substantially rhombic. An air inlet  180  of the airbag is connected to an inflating module  400  on the vehicle. The inflating module  400  includes a sensor, a collision sensor, and an inflator. 
     When a car collision occurs and the acceleration of impact exceeds the predetermined threshold of the inflating module  400 , the inflator of the inflating module  400  would be instantly ignited to deploy the bag body  100  of the airbag via the air inlet  180 . In the airbag, as discussed above, the thickness of expansion of the bag body  100  is restrained by the sealing portions  130 , the buffering pad  300  is expanded and pulled in a planar manner, the bag body  100  bulges toward the opposite back surface  120 , a buffering space  170  is formed between the buffering pad  300  and the cushioning surface  110 , and the buffering pad  300  of the airbag faces the occupant  500 . Hence, while a car collision occurs to make the airbag be inflated and the acceleration caused by the car collision makes the occupant  500  encounter the inflated airbag, the occupant  500  will sequentially contact the buffering pad  300  and the buffering space  170  before contacting the bag body  100 , and the compressing pressure can be relieved by the opening portions  320  communicated with the buffering space  170 . As a result, the occupant  500  can be prevented from directly contacting the hard bag body  100  that caused by the fully saturated air pressure inside, and thus injuries of the contacting portions of the body of the occupant  500  can be avoided. 
     In other words, according to the airbag with multiple layers of progressive cushioning effect of the first embodiment, the buffering pad  300 , the buffering space  170 , and the bag body  100  provide multiple layers of progressive cushioning effect. While a car collision occurs, the multiple layers of progressive cushioning effect provided by the buffering pad  300  and the buffering space  170  can reduce the impact force with which the occupant  500  contacts the bag body  100  and thus avoid the injuries of the contacting portions of the body of the occupant  500 . Moreover, with the isolation provided by the bag body  100 , the occupant  500  can be prevented from contacting hard objects in the vehicle such as the steering wheel or the dashboard. Hence, the purpose of protecting the occupant  500  can be better achieved. 
     When the occupant  500  contacts the bag body  100 , the vents  150  can further relieve the inner pressure of the bag body  100  compressed by the occupant  500  while contacting the bag body  100  and relieve the pressure to the outside, so as to prevent the occupant  500  from the larger impact. 
     Referring to  FIG. 7  to  FIG. 8B , an airbag with multiple layers of progressive cushioning effect according to a second example of the first embodiment of the disclosure is installed on a steering wheel and is fully inflated. The air inlet  180  of the airbag is similarly connected to an inflating module  400  on the vehicle. The inflating module  400  includes a sensor, a collision sensor, and an inflator. The progressive cushioning effect provided by the airbag of the second example is similar to that provided by the airbag of the first example, so it will not be recited again here. 
     Referring to  FIG. 9 , an airbag with multiple layers of progressive cushioning effect according to a second embodiment of the disclosure includes a bag body  100 , and air inlet  180 , and a buffering pad  300 . 
     The airbag with multiple layers of progressive cushioning effect according to a second embodiment of the disclosure is installed on a headrest of a seat, so as to protect the head and the neck of the occupant. In order to more clearly express the structure and features of the present disclosure, the bag body  100  is fully inflated. 
     As shown in the figure, the bag body  100  includes a cushioning surface  110  and an opposite back surface  120 , and an air chamber  140  is defined between the cushioning surface  110  and the opposite back surface  120 . A plurality of straight groups of sealing portions  130  are separately disposed between the cushioning surface  110  and the opposite back surface  120 . The example in the figure shows two straight groups of the sealing portions  130 . Each of the straight groups of the sealing portions  130  have a plurality of straightly arranged sealing portions  130 . Portions other than the sealing portions  130  between the cushioning surface  110  and the opposite back surface  120  are communication portions  190 . The air chamber  140  has an air inlet  180  and a plurality of vents  150 . The air inlet  180  of the airbag is connected to an inflating module  400  on the vehicle. The inflating module  400  includes a sensor, a collision sensor, and an inflator. When a car collision occurs and the acceleration of impact exceeds the predetermined threshold of the inflating module  400 , the inflator of the inflating module  400  will be instantly ignited to deploy the bag body  100  of the airbag via the air inlet  180 . 
     The cushioning surface  110  and the opposite back surface  120  of the bag body  100  are sewn to be close to each other by a thread  160 , so as to form the sealing portions  130  between the cushioning surface  110  and the opposite back surface  120 . 
     The buffering pad  300  is made of a material having a good toughness, such as a fabric having a good toughness. Two side peripheries and a plurality of portions (e.g., two portions) at a center region of the buffering pad  300  are respectively connected to two side peripheries and the two straight groups of the sealing portions  130  of the bag body  100 . The buffering pad  300  is located on a side of the bag body  100  proximal to the cushioning surface  110 . The area of the buffering pad  300  is smaller than the area of the cushioning surface  110 . Three buffering spaces  170  are formed between the buffering pad  300  and the cushioning surface  110 . 
     While the airbag is fully inflated, owing to the two straight groups of the sealing portions  130  separately disposed between the cushioning surface  110  and the opposite back surface  120 , the thickness of expansion between the cushioning surface  110  and the opposite back surface  120  of the bag body  100  is restrained at the sealing portions  130 , but the inflated air can still communicate in the air chamber  140  via the communication portions  190 . Hence, while the airbag is inflated, the cushioning surface  110  and the opposite back surface  120  of the bag body  100  are expanded outward, but the thickness of expansion of the portions at or adjacent to the sealing portions  130  are restrained without expanding. Moreover, while the airbag is fully inflated, the bag body  100  and the buffering pad  300  pull each other, so that the buffering pad  300  is expanded in a planar manner. Because two side peripheries and the two straight groups of the sealing portions  130  of the bag body  100  are respectively restrained by the two side peripheries and the two portions at the center region of the buffering pad  300 , and the area of the buffering pad  300  is smaller than the area of the cushioning surface  110  of the bag body  100 , the buffering pad  300  will make the bag body  100  bulge toward the opposite back surface  120  and be in a form of arch-shaped air shield. Furthermore, the three buffering space  170  are clearly formed between the cushioning surface  110  and the buffering pad  300 . Consequently, according to the airbag of the second embodiment of the disclosure, the buffering pad  300 , the buffering space  170 , and the bag body  100  provides multiple layers of progressive cushioning effect. 
     When a car collision occurs and the acceleration of impact exceeds the predetermined threshold of the inflating module  400 , the inflator of the inflating module  400  is instantly ignited to deploy the bag body  100  of the airbag via the air inlet  180 . In the airbag, as discussed above, the thickness of expansion of the bag body  100  is restrained by the sealing portions  130 , the buffering pad  300  is in a U-shaped planar manner, the bag body  100  bulges toward the opposite back surface  120 , the three buffering space  170  are formed between the buffering pad  300  and the cushioning surface  110 , and the U-shaped buffering pad  300  of the airbag faces the head and the neck of the occupant  500 . Hence, while a car collision occurs to make the airbag be inflated and the acceleration caused by the car collision makes the occupant  500  encounter the inflated airbag, the head and neck of the occupant  500  will sequentially contact the buffering pad  300  and the buffering space  170  before contacting the bag body  100 . As a result, the occupant  500  can be prevented from directly contacting the hard bag body  100  that caused by the fully saturated air pressure inside, and thus injuries of the head and neck of the occupant  500  can be avoided. 
     In other words, according to the airbag with multiple layers of progressive cushioning effect of the second embodiment, the buffering pad  300 , the buffering spaces  170 , and the bag body  100  provide multiple layers of progressive cushioning effect. While a car collision occurs, the multiple layers of progressive cushioning effect provided by the buffering pad  300  and the buffering spaces  170  can reduce the impact force with which the occupant  500  contacts the bag body  100  and thus avoid the injuries of the contacting portions of the body of the occupant  500 . Moreover, with the isolation provided by the bag body  100 , the occupant  500  can be prevented from contacting hard objects in the vehicle such as the headrest of the seat. Hence, the purpose of protecting the occupant  500  can be better achieved. 
     When the occupant contacts the bag body  100 , the vents  150  can further relieve the inner pressure of the bag body  100  compressed by the occupant  500  while contacting the bag body  100  and guide the pressure to the outside, so as to prevent the occupant  500  from the larger impact. 
     Although the present disclosure has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims.