Abstract:
A seat belt for a vehicle comprises a first tongue coupled to a first webbing, the first webbing configured to cover portions of a shoulder, a chest, and an abdomen of a passenger; a first buckle coupled to the first tongue; a second tongue coupled to a second webbing, the second webbing configured to cover portions of the abdomen of the passenger; a second buckle coupled to the second tongue; and an actuator configured to upwardly pull the first tongue and the first buckle, wherein the first buckle is coupled to the second buckle; and upon a collision of the vehicle, the actuator operates to separate the first buckle from the second buckle, and the first webbing moves upward, restricting a movement of an upper body of the passenger.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims under 35 U.S.C. §119(a) the benefit of priority to Korean Patent Application No. 10-2014-0173602, filed Dec. 5, 2014, the entire content of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a seat belt for a vehicle. More particularly, the present disclosure relates to a seat belt that can efficiently restrict the lateral movement of a passenger when a vehicle crashes in an oblique direction. 
     BACKGROUND 
     The current three-point seat belt structure is efficient in restricting the movement of a passenger who is deviating toward the front side upon a frontal crash, but has difficulty in maximizing a binding force upon crashes other than the frontal crash. 
     In a representative example of a new oblique crash test which the National Highway Traffic Safety Administration (NHTSA) will be introducing in 2017, a phenomenon that the shoulder of a dummy escapes from the passenger seat by lateral inertia occurring by the impact of an opposite vehicle colliding in an oblique direction is commonly observed. 
     When an impact occurs in a left oblique direction of the driver&#39;s seat in the new oblique crash test, all occupants of driver&#39;s seat and passenger&#39;s seat undergo an eccentric inertia in the left (or right) direction. In this case, the driver may receive help from the curtain airbag and the door trim that are located outside the drivers seat, and may not be affected by the shoulder fastening direction of the three-point seat belt. 
     However, when an occupant of the passenger&#39;s seat undergoes the eccentric inertia in the left direction (inner direction of the occupant), the shoulder of the occupant may escape from the seat belt because the direction of the shoulder fastening direction of the passenger is opposite to that of the driver (see  FIG. 6A  and  FIG. 6B ). 
     Due to the shoulder escaping from the seat belt, injury may significantly increase because of the rotation and the lateral behavior of the head/upper body, leading to significant reduction of points upon crash test and serious losses to a company in field accidents besides the crash test. 
     Accordingly, a new belt restriction structure that can restrict the lateral movement even when the shoulder escapes is needed. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY 
     The present disclosure provides a seat belt for a vehicle that can significantly improve the prevention of injuries to a passenger caused by separation of the shoulder from the seat belt upon collision and can also comply with new North American crash-related regulations, by implementing a new concept for a seat belt structure that restricts lateral movement, and that allows webbing of the seat belt passing the shoulder and chest of a passenger to upwardly move upon new oblique collision of a vehicle and thus effectively restricts the lateral movement of a passenger. 
     In one aspect, the present inventive concept provides a seat belt for a vehicle, comprising a first tongue coupled to a first webbing, the first webbing configured to cover portions of a shoulder, a chest, and an abdomen of a passenger; a first buckle coupled to the first tongue; a second tongue coupled to a second webbing, the second webbing configured to cover portions of the abdomen of the passenger; a second buckle coupled to the second tongue; and an actuator configured to upwardly pull the first tongue and the first buckle, wherein the first buckle is coupled to the second buckle; and upon a collision of the vehicle, the actuator operates to separate the first buckle from the second buckle, and the first webbing moves upward, restricting a movement of an upper body of the passenger. 
     The first tongue and the first buckle may be coupled to the second tongue and the second buckle by a molding pin disposed between the first buckle and the second buckle, and when a sufficient force is applied, the molding pin breaks, separating the first tongue and the first buckle from the second tongue and the second buckle. 
     The first buckle may be connected to a strap extending from a piston rod of the actuator, such that the first tongue and the first buckle are pulled by the strap when the actuator operates. 
     The second buckle may comprise a push button mounted therein, the push button configured to release the first tongue and the second tongue when the push button is pushed. 
     A first locking lever may be configured to couple to the first tongue and a second locking lever configured to couple to the second tongue, wherein the push button is configured to release the tongues from the locking levers when the push button is pushed. 
     The first webbing may be configured to extend from a retractor through a D-ring and the first tongue to a lower anchor disposed on the same side of the vehicle as the retractor. 
     The second webbing may be configured to extend from the lower anchor to the second tongue. 
     The actuator may comprise a pneumatic actuator that expands rapidly upon a collision signal. 
     Other aspects and exemplary embodiments of the inventive concept are discussed infra. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the present inventive concept will now be described in detail with reference to certain exemplary embodiments thereof illustrated in the accompanying drawings which are given hereinbelow by way of illustration only, and thus are not limitative of the present inventive concept, and wherein: 
         FIG. 1  is a perspective view illustrating a seat belt according to an embodiment of the present inventive concept; 
         FIG. 2  is perspective and cross-sectional views illustrating a dual tongue/buckle structure of a seat belt according to an embodiment of the present inventive concept; 
         FIG. 3  is a side view illustrating states before and after dual tongue/buckle separation of a seat belt according to an embodiment of the present inventive concept; 
         FIG. 4  is perspective and front views illustrating a state before the operation of a seat belt according to an embodiment of the present inventive concept; 
         FIG. 5  is perspective and front views illustrating a state after the operation of a seat belt according to an embodiment of the present inventive concept; and 
         FIG. 6A  and  FIG. 6B  are photographs illustrating the behavior of a dummy upon new oblique crash of a current three-point seat belt type. 
     
    
    
     It should be understood that the accompanying drawings are not necessarily to scale, presenting a somewhat simplified representation of various exemplary features illustrative of the basic principles of the inventive concept. The specific design features of the present inventive concept as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
     In the figures, reference numbers refer to the same or equivalent parts of the present inventive concept throughout the several figures of the drawing. 
     DETAILED DESCRIPTION 
     Hereinafter reference will now be made in detail to various embodiments of the present inventive concept, examples of which are illustrated in the accompanying drawings and described below. While the inventive concept will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the inventive concept to those exemplary embodiments. On the contrary, the inventive concept is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the inventive concept as defined by the appended claims. 
     It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
     The above and other features of the inventive concept are discussed infra. 
     Hereinafter, exemplary embodiments of the present inventive concept will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present inventive concept. 
       FIG. 1  is a perspective view illustrating a seat belt according to an embodiment of the present inventive concept. 
     As shown in  FIG. 1 , a tongue and a buckle of a dual type are shown. 
     A first tongue  11  connected to a first webbing ( 10  in  FIGS. 4 and 5 ) covering the shoulder, chest, and abdomen of a passenger and a second tongue  14  connected to a second webbing ( 13  in  FIGS. 4 and 5 ) covering the abdomen of a passenger may be integrally coupled to each other while the rear surfaces thereof make contact with each other. 
     Also, a first buckle  12  and a second buckle  15  to be coupled to the first tongue  11  and the second tongue, respectively, may be integrally coupled to each other while the rear surfaces thereof make contact with each other. 
     In this case, the second buckle  15  may be connected to the upper end of a buckle strap  26  at one side of a seat cushion  100 , and thus the first buckle  12  and the second buckle  15  that are integral type may be supported by the buckle strap  26 , the lower end of which is fixed to an anchor mount (not shown) located at the outside. 
     Also, the first buckle  12  may be connected to a strap  19  extending from the lower end of the side surface of a seat back  110 . 
     That is, the first buckle  12  may be supported by the side of the seat back  110 , and may be connected with a strap (wire) structure so as not to be affected by seating position and buckle position. 
     The strap  19  may be connected to a piston rod  27  of an actuator  16  described later, and may move in accordance with the operation of the piston rod  27 . 
     Also, the strap  19  may be implemented in a bellows-type which enables a slight length adjustment of the strap  19  such that an interference does not occur even when the seat back leans back or stands up. 
     Here, a seatback slit  18  may be formed in the side surface of the seat back  100  in order to secure the moving path of the strap  19 . The strap  19  may move up along the seatback slit  18 . 
     In the seatback slit  18 , a notch may be formed in a seat covering, and an internal seat foam may be cut, allowing the strap  19  to move while tearing down the notch. 
     In such a dual type of tongue and buckle structure, one webbing may be fixed to the current location, and the other webbing may move up upon the vehicle collision. 
     For example, the second tongue  14  and the second buckle  15  may remain in their locations, and the first tongue  11  and the first buckle  12  may be separated from the second tongue  14  and the second buckle  15  and may move upward. 
     Accordingly, upon vehicle collision, and in particularly, upon an oblique crash, the first tongue and the first buckle may be separated from the second tongue and the second buckle by the operation of the actuator, and simultaneously, the first webbing may move upward, restricting the movement of the upper body of a passenger and thus preventing the shoulder of a passenger from escaping from the seat belt. 
     Here, the reference numeral  20  may be a push button for releasing the coupling state between the tongue and the buckle. 
       FIG. 2  shows perspective and cross-sectional views illustrating a dual tongue/buckle structure of a seat belt according to an embodiment of the present inventive concept. 
     As shown in  FIG. 2 , the first tongue  11  and the first buckle  12  may be integrally connected to the second tongue  14  and the second buckle  15  by a molding pin  17  interposed between the contact surfaces thereof. 
     The molding pin connection part may be formed on about two places at the side of the tongue and on about three places at the side of the buckle, and may be formed of a plastic material so as to be easily broken when a certain load is applied thereto. The molding pin may be coupled while buckle bases are making contact with each other before part assembly in the buckle and buckle cover finishing. 
     Here, the molding pin may include a capsule (molding pin) that prevents a certain shrinkage phenomenon of a current column. 
     The capsule attached to the current column may be designed such that the shear limit load becomes about 35 kgf to about 40 kgf, and may not be separated under ordinary conditions. 
     The shear limit load assigned to the capsule that is being applied to the column may be assigned to the molding pin. 
     For example, the actuator that moves up the first buckle upon collision may use the same device as a pre-tensioner of seat belt retractor/anchor, and when a shear load of about 2 kN and about 200 kgf is applied in an existing test, the molding pin may be broken, inducing separation. 
     Accordingly, when an external force of about 200 kgf is applied, the molding pin  17  may be broken, separating the first tongue  11  and the first buckle  12  from the second tongue  14  and the second buckle  15 . 
     Meanwhile, the release principle of basic coupling between the tongue and the buckle may be identical to the existing release principle of coupling between tongue and buckle. 
     For example, the push button  20  may be mounted in the second buckle  15  in order to release the tongue. In this case, two push pieces  21   a  and  21   b  extending from a lower portion of the push button  20  in a horizontal direction may be formed. 
     Here, a lower push piece  21   b  of the two push pieces  21   a  and  21   b  may extend longer than the upper push piece  21   a  so as to release the coupling between the first tongue  11  and the first buckle  12 , and may extend to the inside of the first buckle  12  through a slit  28  of a vertical cut form in the first buckle  12 . 
     Also, a connection rod  31  may be disposed to be supported by a spring  29  in the first buckle  12  and be connected to a locking lever  22   b  in the first buckle  12  through a connection rod strap  30 . The end portion of the push piece  21   b  may be disposed on and make contact with the upper portion of the connection rod. 
     Thus, when the push button  20  is pushed, the upper push piece  21   a  may directly push the lower end portion of the locking lever  22   a  hooking the second tongue  14 , and the lower push piece  21   b  may push the connection rod and simultaneously, the lower end portion of the locking lever  22   b  hooking the first tongue  11  may be pulled while the connection rod strap  30  is pulled by the downward movement of the connection rod  31 , thereby releasing the coupling of the first tongue  11  and the second tongue  14  while the locking levers  22   a  and  22   b  are pivoting about hinge parts. 
     Here, as the release of the tongue coupling by the pivoting operation of the locking lever, the coupling between the tongue and the locking lever, and the returning method of the push button are well known to those of skill in the art, detailed descriptions thereof will be omitted herein. 
       FIG. 3  is a side view illustrating states before and after dual tongue/buckle separation of a seat belt according to an embodiment of the present inventive concept. 
     As shown in  FIG. 3 , the actuator  16  may be disposed in the seat back  110 , and the piston rod  27  of the actuator  16  may be connected to the first buckle  12  through the strap  19 . 
     Here, the actuator  16  may explosively retract the piston rod  27  by a collision signal, and a pneumaticactuator that retracts the piston rod  27  up may be employed. 
     For example, when an accident occurs, the seat belt may be inversely rolled so as to fix a passenger to the seat. Simultaneously, a gas chamber such as an anchor pre-tensioner that is being currently applied to vehicles may be disposed at the side of the seat back, and the strap  19  connected to the first buckle  12  may be upwardly pulled upon explosion. 
     Here, any method in which the actuator is explosively operated by the collision signal can be adopted without a special limitation if ordinarily known in the art. 
     Accordingly, when the actuator  16  operates upon vehicle crash, an upwardly pulling force may be applied to the strap  19 , the first buckle  12  connected to the strap  19 , and the first tongue coupled to the first buckle  12  due to the movement of the piston rod  27 . Due to the pulling force, the molding pin  17  connecting between the first tongue  11  and the second tongue  14  and between the first buckle  12  and the second buckle  15  may be broken. 
     At the same time as the breakage of the molding pin  17 , the first tongue  11  and the first buckle  12  may be separated from the second tongue  14  and the second buckle  15  and may move upward. Simultaneously, the passenger fixing location of the first webbing  10  hung on the first tongue  14  may move up, and thus the movement of the upper body of a passenger may be restricted. 
       FIGS. 4 and 5  are perspective and front views illustrating states before and after the operation of a seat belt according to an embodiment of the present inventive concept. 
     As shown in  FIGS. 4 and 5 , the seat belt may include two webbings, i.e., a first webbing  10  and a second webbing  13 . The first webbing  10  and the second webbing  13  can together restrict the movement of the upper body of a passenger. 
     For example, the first webbing  10  may upwardly extend from a retractor  23  and may pass through a D-ring  24 . Thereafter, the first webbing  10  may downwardly extend to the first tongue  11 , and then may be connected to a lower anchor  25  disposed at the side of the retractor  23 , covering the chest and abdomen of a passenger and restricting the movement of the upper body of a passenger. 
     Also, the second webbing  13  may extend from the lower anchor  25  at the side of the retractor  23 , and may be connected to the second tongue  14 , covering the abdomen of a passenger and restricting the movement of the abdomen of a passenger. 
     Also, similarly to the three-point belt, the first tongue  11  and the second tongue  14  connected to the first webbing  10  and the second webbing  13  may be coupled to and decoupled from the first buckle  12  and the second buckle  15  while being coupled together during normal operation. However, when an accident occurs and a certain load is applied, the molding pin  17  may be broken and thus the first tongue  11  and the second tongue  14  may be separated from each other. 
     Accordingly, upon a vehicle collision, and in particular, upon an oblique crash, the strap  19 , the first buckle  12 , and the first tongue  11  may be separated and upwardly pulled by the actuator  16 , and simultaneously, the first webbing  10  may also be upwardly pulled to cover the upper portion of the upper body of a passenger. 
     That is, the first tongue  11  and the first buckle  12  may move upwardly and reinforce the restriction of the movement of the upper body of a passenger while the second tongue  14  and the second buckle  15  maintain their original locations. Thus, the restriction of the movement of the abdomen of a passenger can be maintained similarly to that of a typical three-point belt, and thus a stabler belt restriction region can be secured than a four-point belt. 
     Thus, the present inventive concept provides excellent performance in restricting the lateral movement of a passenger by applying a dual tongue/buckle type to the seat belt. Also, the present inventive concept complies with new North American safety regulations, and in addition, it can improve the safety of occupants upon an oblique crash. 
     A seat belt for a vehicle according to an embodiment of the present inventive concept has the following advantages. 
     First, because a buckle part separates and the webbing of the seat belt upwardly moves so as to restrict the movement of the shoulder of a passenger upon an oblique crash, the lateral movement of a passenger can be effectively restricted, thereby preventing injury to a passenger. 
     Second, the present inventive concept can provide an innovative solution for injury prevention for a passenger seat that satisfies new North American oblique crash-related regulations, and thus can better comply with the new safety regulations. 
     Third, the present inventive concept improves lateral movement control upon existing side collision and other collisions in addition to complying with the new safety regulations. 
     Fourth, compared to a four-point belt, because the structure and exterior of a current three-point belt can be more easily maintained, it is advantageous for customer intimacy and marketability maintenance (four-point belts require extensive modification in the design of interiors and related parts). 
     The inventive concept has been described in detail with reference to exemplary embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the inventive concept, the scope of which is defined in the appended claims and their equivalents.