Patent Publication Number: US-2020290555-A1

Title: Multi-point seat belt system

Description:
This application claims the benefit of Taiwan patent application No. 108108109, filed on Mar. 11, 2019. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a multi-point seat belt system, and more particularly to a multi-point seat belt system that is applied to a seat of various vehicles. 
     2. Description of Related Art 
     Based on high safety requirements for various vehicles such as sport utility vehicles, racing cars or tanks, a multi-point seat belt system is disposed on a seat of the above-mentioned various vehicles. Every occupant in a vehicle can be simultaneously limited by distributed fixing points for fixing on a seat in the vehicle steadily. When an external force is applied to the vehicle, the occupant can be secured on the seat with a sufficient protection effect. 
     In a conventional multi-point seat belt system, the type of the conventional multi-point seat belt can be differentiated by the amount of the fixing points and may be a four-point type, a five-point type, a six-point type, or a seven-point type. Take a six-point type seat belt system for example. The six-point type seat belt system has one or two retractors, a buckling device, and four auxiliary webbings. The buckling device has a buckle assembly and a tongue assembly. The one or the two retractors are disposed on a top end of the seat or a rear side of a seat back of the seat in the vehicle. Two shoulder webbings can be locked by the two retractors and are respectively connected to the buckle assembly and the tongue assembly. The four auxiliary webbings are disposed beside two sides of the seat and are respectively connected to the buckle assembly and the tongue assembly. Six fixing points are formed by the two shoulder webbings and the four auxiliary webbings and are distributed around the seat. 
     When the buckling device of the six-point type seat belt system is correctly locked, an tilt locking mechanism disposed in each one of the retractors is locked, or when the retractors are locked due to emergency deceleration or brake, the shoulder webbings are uni-directionally locked by the retractors due to the change of the tension of the shoulder webbings. The auxiliary webbings distributed around the seat are connected to the buckling device for providing the supporting pulling force. The occupant restricted on the seat is safe. 
     Furthermore, the one or the two retractors of the conventional multi-point seat belt system are the emergency locking retractors (ELR). In use, the two shoulder webbings provided by the one or the two retractors disposed on the top end of the seat or the rear side of the seat back of the seat can be locked emergently. The two shoulder webbings are respectively connected to the buckle assembly and the tongue assembly of the buckling device. The auxiliary webbings are distributed around the seat and are respectively connected to the buckle assembly and the tongue assembly of the buckling device. The auxiliary webbings are simply connected to the seat and cannot be retracted and locked. When the vehicle is tilted, decelerated or braked in emergency, the shoulder webbings are locked by the one or the two retractors in the conventional multi-point seat belt system. Thus, the protection and the safety of the conventional multi-point seat belt system are insufficient. 
     For increasing the safety of the conventional multi-point seat belt system, multiple length adjusting buckles are respectively disposed on the auxiliary webbings to adjust lengths of the auxiliary webbings for suiting different occupants. The occupant can be certainly restricted on the seat by the conventional multi-point seat belt system with the length adjusting buckles for increasing the safety and the protection of the conventional multi-point seat belt system. 
     However, when the occupant sits on the seat and fastens the conventional multi-point seat belt system, the buckling device is downwardly pushed by the occupant and moves to a position adjacent to a center of a pelvis of the occupant, and then the occupant adjust the lengths of the auxiliary webbings adjacent to a waist respectively. The operation of the conventional multi-point seat belt system is inconvenient and time-consuming. 
     To overcome the shortcomings, the present invention provides a multi-point seat belt system to mitigate or obviate the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     The objective of the invention is to provide a multi-point seat belt system that can solve the problems of the conventional multi-point seat belt system, such as that the protection is insufficient, and the operation is inconvenient and time-consuming. 
     The multi-point seat belt system has a webbing locking device, an emergency locking-retracting mechanism, and two automatic locking retractors. 
     The webbing locking device has a buckle assembly and a tongue assembly. The buckle assembly has a buckle base and a locking assembly. The buckle base is rigid and has a first connecting portion and a first insertion portion. The first insertion portion of the buckle assembly is formed below the first connecting portion and has a first through hole formed through the first insertion portion. The locking assembly is disposed on the buckle base. The tongue assembly has a tongue base. The tongue base is rigid and has a tongue portion, a second connecting portion, and a second insertion portion. The tongue portion is selectively inserted into the locking assembly of the buckle assembly for locking or unlocking. The second connecting portion and the second insertion portion are formed on an end of the tongue portion. The second connecting portion is located above the second insertion portion. The second insertion portion has a second through hole formed through the second insertion portion. 
     The emergency locking-retracting mechanism has at least one emergency locking retractor and two shoulder webbings. The two shoulder webbings are connected to the at least one emergency locking retractor for being extracted, retracted, and locked automatically. One of the two shoulder webbings is connected to the first connecting portion of the buckle assembly. The other one of the two shoulder webbings is connected to the second connecting portion of the tongue assembly. The emergency locking-retracting mechanism is adapted to be disposed on a seat or a vehicle body. 
     Each one of the two automatic locking retractors has a lower webbing being extracted, retracted, and locked automatically. The two automatic locking retractors are adapted to be disposed on two sides of the seat. The lower webbing of one of the two automatic locking retractors is inserted through the first through hole of the first insertion portion and is disposed on a side of a cushion of the seat. The lower webbing of the other one of the two automatic locking retractors is inserted through the second through hole of the second insertion portion and is disposed on another side of the cushion of the seat. 
     In addition, the multi-point seat belt system has a webbing locking device, an emergency locking-retracting mechanism, and two automatic locking retractors. 
     The webbing locking device has a buckle assembly, a tongue assembly, and two sliding members. The buckle assembly has a buckle base and a locking assembly. The buckle base is rigid and has a first connecting portion and a first insertion portion. The first insertion portion is formed below the first connecting portion and has a first through hole formed through the first insertion portion of the buckle base. The locking assembly is disposed on the buckle base. 
     The tongue assembly has a tongue base. The tongue base is rigid and has a tongue portion, a second connecting portion, and a second insertion portion. The tongue portion is selectively inserted into the locking assembly of the buckle assembly for locking or unlocking. The second connecting portion and the second insertion portion are formed on an end of the tongue portion. The second insertion portion is located above the second connecting portion. The second insertion portion has a second through hole formed through the second insertion portion of the tongue base. 
     One of the two sliding members is inserted through the first through hole of the first insertion portion of the buckle assembly and is able to move relative to the first insertion portion of the buckle base. The other one of the two sliding members is inserted through the second through hole of the second insertion portion of the tongue assembly and is able to move relative to the second insertion portion of the tongue base. Each one of the two sliding members has a through groove being inclined. 
     The emergency locking-retracting mechanism has at least one emergency locking retractor and two shoulder webbings. The two shoulder webbings are connected to the at least one emergency locking retractor for being extracted, retracted, and locked automatically. One of the two shoulder webbings is inserted through the first through hole of the first insertion portion of the buckle assembly and the through groove of one of the two sliding members. The other one of the two shoulder webbings is inserted through the second through hole of the second insertion portion of the tongue assembly and the through groove of the other one of the two sliding members. The emergency locking-retracting mechanism is adapted to be disposed on a seat or a vehicle body. The two shoulder webbings are respectively disposed on two sides of a cushion of the seat. 
     Each one of the two automatic locking retractors has a lower webbing being extracted, retracted, and locked automatically. The lower webbing of one of the two automatic locking retractors is connected to the first connecting portion of the buckle assembly. The lower webbing of the other one of the two automatic locking retractors is connected to the second connecting portion of the tongue assembly. The two automatic locking retractors are adapted to be disposed on two sides of the seat. 
     The multi-point seat belt system is applied to the seat of the vehicle, provides multiple distributed fixing points to fix an occupant on the seat for protecting the occupant, and has the following advantages: 
     1. Promote the safety protection performance of the multi-point seat belt system: the emergency locking-retracting mechanism of the multi-point seat belt system is disposed on the seat or the vehicle body by the at least one emergency locking retractor and provides the two shoulder webbings able to be locked emergently. The two automatic locking retractors are disposed on the two sides of the seat and provide two lower webbings able to be locked. The webbing locking device is connected between the two shoulder webbings of the emergency locking-retracting mechanism and the two lower webbings of the two automatic locking retractors. The two shoulder webbings are respectively inserted through the webbing locking device and are respectively extended to and fixed on the two sides of the seat. The two lower webbings are respectively inserted through the webbing locking device and are respectively extended to and fixed on the two sides of the seat. The buckle assembly and the tongue assembly are buckled correctly. When the vehicle is tilted, decelerated or braked in emergency, the two shoulder webbings are locked by the at least one emergency locking retractor immediately. The two lower webbings can be retracted and locked by the two automatic locking retractors. The shoulder webbings and the lower webbings are distributed around a body of the occupant and can fasten the occupant on the seat steadily for promoting the safety protection performance of the multi-point seat belt system. 
     2. Convenient operation: as above-described, the two shoulder webbings in the emergency locking-retracting mechanism can be pulled freely. When the vehicle is tilted, decelerated or braked in emergency, the two shoulder webbings can generate a locking function. The lower webbing of each one of the two automatic locking retractors can be pulled, is retracted automatically to a suitable length for fitting the occupant, and then is locked. When the occupant sitting on the seat fastens the multi-point seat belt system, the webbing locking device can be moved to a position adjacent to a center of a pelvis of the occupant by the occupant. When the webbing locking device is moving, the two shoulder webbings and the two lower webbings can be pulled and extended to the suitable lengths automatically. The length adjustments of the two shoulder webbings and the two lower webbings are not manually but automatically done. The occupant can fasten the multi-point seat belt system quickly and conveniently. 
     In the multi-point seat belt system, the at least one emergency locking retractor is disposed on the seat or the vehicle body. The two shoulder webbings are able to be locked emergently, are respectively inserted through the buckle assembly and the tongue assembly of the webbing locking device, and are respectively extended and connected to the two sides of the seat. The first insertion portion in the buckle assembly and the second insertion portion in the tongue assembly both have the moveable sliding members respectively. One of the two shoulder webbings is inserted through the first through hole of the first insertion portion of the buckle assembly and the through groove of the sliding member disposed in the first through hole of the first insertion portion. The other one of the two shoulder webbings is inserted through the second through hole of the second insertion portion of the tongue assembly and the through groove of the sliding member disposed in the second through hole of the second insertion portion. The two shoulder webbings passing through the buckle assembly and the tongue assembly can be locked or unlocked by the two sliding members respectively. After locking, the lengths of the lower sections of the two shoulder webbings cannot be extended even though the buckle assembly slides relative to the tongue assembly. The safety protection performance of the multi-point seat belt system is good. After unlocking, the tongue assembly is buckled to the buckle assembly, and the shoulder webbings can slide relative to the buckle assembly and the tongue assembly temporarily for increasing the operation of the multi-point seat belt system. 
     The multi-point seat belt system has a shoulder webbing connecting device. The shoulder webbing connecting device is selectively disposed between the two shoulder webbings for limiting a distance between the two shoulder webbings. When the vehicle is tilted, decelerated or braked in emergency, the two shoulder webbings cannot fall off from two shoulders of the occupant for ensuring the safety protection performance of the multi-point seat belt system. 
     Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front side view of a first embodiment of a multi-point seat belt system in accordance with the present invention; 
         FIG. 2  is a front side view of a second embodiment of a multi-point seat belt system in accordance with the present invention; 
         FIG. 3  is an exploded perspective view of a webbing locking device of the multi-point seat belt system in  FIGS. 1 and 2 ; 
         FIG. 4  is another exploded perspective view of the webbing locking device of the multi-point seat belt system in  FIGS. 1 and 2 ; 
         FIG. 5  is an enlarged front side view of an automatic locking retractor of the multi-point seat belt system in  FIGS. 1 and 2 ; 
         FIG. 6  is an enlarged side view of the automatic locking retractor of the multi-point seat belt system in  FIGS. 1 and 2 ; 
         FIG. 7  is another enlarged front side view of the automatic locking retractor of the multi-point seat belt system in  FIGS. 1 and 2 ; 
         FIG. 8  is another enlarged side view of the automatic locking retractor of the multi-point seat belt system in  FIGS. 1 and 2 ; 
         FIG. 9  is an enlarged front side view of the multi-point seat belt system in  FIGS. 1 and 2 , showing a buckle assembly of the webbing locking device has an buckle outer shell, and a tongue assembly of the webbing locking device has a tongue outer shell; 
         FIG. 10  a front side view of the multi-point seat belt system in  FIG. 1 , showing the multi-point seat belt system has a shoulder webbing connecting device; 
         FIG. 11  is a front side view of the multi-point seat belt system in  FIG. 2 , showing the multi-point seat belt system has a shoulder webbing connecting device; 
         FIG. 12  is an operational front side view of the multi-point seat belt system in  FIGS. 2 and 9 , showing the multi-point seat belt system is disposed on a seat with an occupant; 
         FIG. 13  is a front side view of a third embodiment of a multi-point seat belt system in accordance with the present invention; 
         FIG. 14  is a front side view of a fourth embodiment of a multi-point seat belt system in accordance with the present invention; 
         FIG. 15  is an exploded perspective view of a webbing locking device of the multi-point seat belt system in  FIGS. 13 and 14 ; 
         FIG. 16  is another exploded perspective view of the webbing locking device of the multi-point seat belt system in  FIGS. 13 and 14 ; 
         FIG. 17  is an exploded perspective view of a buckle assembly and one of two sliding members of the webbing locking device in  FIGS. 13 to 15 ; 
         FIG. 18  is another exploded perspective view of the buckle assembly and one of the two sliding members of the webbing locking device in  FIGS. 13 to 15 ; 
         FIG. 19  is an exploded perspective view of a tongue assembly and the other one of the two sliding members of the webbing locking device in  FIGS. 13 to 15 ; 
         FIG. 20  is another exploded perspective view of the tongue assembly and the other one of the two sliding members of the webbing locking device in  FIGS. 13 to 15 ; 
         FIG. 21  is a perspective view of each one of the sliding members in  FIGS. 16 to 20 ; 
         FIG. 22  is an enlarged side view in partial section of the webbing locking device in  FIGS. 16 to 20 , showing one of the two sliding members is disposed in the buckle assembly or the tongue assembly; 
         FIG. 23  is an operational side view of the webbing locking device in  FIGS. 16 to 20 , showing one of the two sliding members moves relative to the buckle assembly or the tongue assembly for clipping one of the shoulder webbings; 
         FIG. 24  is an enlarged front side view of the multi-point seat belt system in  FIGS. 13 and 14 , showing the buckle assembly of the webbing locking device has an buckle outer shell, and the tongue assembly of the webbing locking device has a tongue outer shell; 
         FIG. 25  is a front side view of the multi-point seat belt system in  FIG. 14 , showing the multi-point seat belt system has a shoulder webbing connecting device; and 
         FIG. 26  is an operational front side view of the multi-point seat belt system in  FIG. 14 , showing the multi-point seat belt system is disposed on a seat. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to  FIGS. 1 and 2 , a first embodiment and a second embodiment of a multi-point seat belt system A in accordance with the present invention both comprise a webbing locking device  1 A, an emergency locking-retracting mechanism  9 , and two automatic locking retractors (ALR)  4 A,  4 A′. The difference between the first embodiment and the second embodiment of multi-point seat belt system A is in the structures of the emergency locking-retracting mechanisms  9 . The rest of structures of multi-point seat belt system A is the same. 
     With reference to  FIGS. 1 to 4 , the webbing locking device  1 A is connected to the emergency locking-retracting mechanism  9  and the two automatic locking retractors  4 A,  4 A′, and has a buckle assembly  10 A and a tongue assembly  20 A. The tongue assembly  20 A is selectively locked or unlocked to the buckle assembly  10 A. 
     With reference to  FIGS. 1 to 4 , the buckle assembly  10 A has a buckle base  11  and a locking assembly  12 . The buckle base  11  is a rigid base and is made of a rigid material or a metallic material, such as steel. The buckle base  11  has a body  111 , a first connecting portion  112 , and a first insertion portion  113 . The first connecting portion  112  and the first insertion portion  113  are formed on an end of the body  111 . The first connecting portion  112  is formed above the first insertion portion  113  and has a first connecting hole  1121  formed through the first connecting portion  112 . The first insertion portion  113  has a first through hole  1131 . The first through hole  1131  is formed through the first insertion portion  113  and is an elongated hole. 
     The locking assembly  12  is disposed on the body  111  of the buckle base  11 . The locking assembly  12  has a locking mechanism  121  and a pressing member  122 . The locking mechanism  121  is disposed on the body  111  of the buckle base  11 . The pressing member  122  can selectively drive the locking mechanism  121  to change a locked state to an unlocked state. The locking assembly  12  can be selected from a known product and will not be described herein. 
     With reference to  FIGS. 1 to 4 , the tongue assembly  20 A has a tongue base  21 . The tongue base  21  is a rigid base and is made of a rigid material or a metallic material, such as steel. The tongue base  21  has a tongue portion  211 , a second connecting portion  212 , and a second insertion portion  213 . The second connecting portion  212  and the second insertion portion  213  are formed on an end of the tongue portion  211 . The second connecting portion  212  is located above the second insertion portion  213 . The second connecting portion  212  has a second connecting hole  2121  formed through the second connecting portion  212 . The second insertion portion  213  has a second through hole  2131 . The second through hole  2131  is formed through the second insertion portion  213  and is an elongated hole. The tongue portion  211  of the tongue assembly  20 A can be selectively inserted into and is locked in the locking assembly  12  of the buckle assembly  10 A. When the pressing member  122  of the locking assembly  12  is pressed, the locking assembly  12  can release the tongue assembly  20 A. 
     With reference to  FIG. 9 , in the webbing locking device  1 A, the buckle assembly  10 A has a buckle outer shell  13 . The buckle outer shell  13  of the buckle assembly  10 A covers the buckle base  11  and the locking assembly  12 . The first connecting portion  112  of the buckle base  11 , the first insertion portion  113 , and the pressing member  122  of the locking assembly  12  are exposed out of the buckle outer shell  13 . The tongue assembly  20 A has a tongue outer shell  22 . The tongue outer shell  22  of the tongue assembly  20 A covers the tongue base  21 . The tongue portion  211  of the tongue base  21 , the second connecting portion  212 , and the second insertion portion  213  are exposed out of the tongue outer shell  22 . 
     With reference to  FIGS. 1, 2, and 12 , the emergency locking-retracting mechanism  9  is adapted to be disposed on a seat of a vehicle, a seat back of the seat, or a back side of the seat. The emergency locking-retracting mechanism  9  has at least one emergency locking retractor (ELR)  2 A,  2 A′ and two shoulder webbings  3 A,  3 A′. The two shoulder webbings  3 A,  3 A′ are connected to the at least one emergency locking retractor  2 A,  2 A′ for being extracted, retracted, and locked automatically. One of the two shoulder webbings  3 A is connected to the first connecting portion  112  of the buckle assembly  10 A. The other one of the two shoulder webbings  3 A′ is connected to the second connecting portion  212  of the tongue assembly  20 A. 
     With reference to  FIG. 1 , the amount of the at least one emergency locking retractor  2 A is one. The two shoulder webbings  3 A,  3 A′ are connected to each other to form a Y-shaped webbing for connecting the emergency locking retractor  2 A. With reference to  FIG. 2 , the amount of the at least one emergency locking retractor  2 A,  2 A′ is two. The two shoulder webbings  3 A,  3 A′ are respectively connected to the two emergency locking retractors  2 A,  2 A′. 
     With reference to  FIGS. 1, 2, and 12 , the two automatic locking retractors  4 A,  4 A′ are adapted to be disposed on two sides or the outside of the seat in the vehicle. Each one of the two automatic locking retractors  4 A,  4 A′ has a lower webbing  5 A,  5 A′ being extracted, retracted, and locked automatically. The webbing locking device  1 A is connected between the two shoulder webbings  3 A,  3 A′ of the emergency locking-retracting mechanism  9  and the two lower webbings  5 A,  5 A′ of the two automatic locking retractors  4 A,  4 A′ for providing multiple distributed fixing points around the seat. 
     The at least one emergency locking retractor  2 A,  2 A′ can be selected from a known emergency locking retractor. Each one of the two automatic locking retractors  4 A,  4 A′ can be selected from a known automatic locking retractor. With reference to  FIGS. 5 to 8 , each one of the two automatic locking retractors  4 A,  4 A′ has a base  41 , a retracting member  42 , a stopper  43 , a torsion spring  44 , and a lower webbing  5 A,  5 A′. The retracting member  42  can be a one-way ratchet mechanism, is rotatably disposed on the base  41 , and is connected to an end of the lower webbing  5 A,  5 A′. The retracting member  42  has a ratchet  421 , a return spring  422 , and a cover  423 . The ratchet  421  is mounted on the base  41  and has at least one notch  424 . The at least one notch  424  is formed on the ratchet  421  at a spaced interval. The return spring  422  is disposed on the base  41  and is connected to the ratchet  421  for retracting. The cover  423  is disposed on the base  41  and covers the return spring  422 . The retracting member  42  can retract the lower webbing  5 A,  5 A′ automatically. The stopper  43  is connected to the torsion spring  44 , is disposed on the base  41  in an oscillating manner, and is located beside the retracting member  42 . The torsion spring  44  provides an elastic force to the stopper  43  for timely stopping the retracting member  42  to rotate by an elastic force provided by the torsion spring  44 . The stopper  43  driven by the torsion spring  44  can be inserted into the at least one notch  424  of the ratchet  421  for positioning the ratchet  421 . With reference to  FIGS. 5 and 6 , the torsion spring  44  is connected between an end of the stopper  43  and the base  41 . With reference to  FIGS. 7 and 8 , the torsion spring  44  is connected between a middle section of the stopper  43  and the base  41 . 
     With reference to  FIGS. 10 and 11 , in the first embodiment and the second embodiment of the multi-point seat belt system A, the multi-point seat belt system A further has a shoulder webbing connecting device  8 . The shoulder webbing connecting device  8  is selectively disposed between the two shoulder webbings  3 A,  3 A′ for limiting a distance between the two shoulder webbings  3 A,  3 A′. The shoulder webbing connecting device  8  has two webbing sheaths  80  and a buckling assembly  81 . The two webbing sheaths  80  are respectively and detachably disposed around the two shoulder webbings  3 A,  3 A′. The buckling assembly  81  is detachably connected between the two webbing sheaths  80 . The webbing sheaths  80  and the buckling assembly  81  can be selected from the known products and will not be described herein. 
     With reference to  FIGS. 1, 2, 9, and 12 , in the first embodiment and the second embodiment of the multi-point seat belt system A, the at least one emergency locking retractor  2 A,  2 A′ of the emergency locking-retracting mechanism  9  is adapted to be disposed on a top end of the seat back of the seat in the vehicle, or a back side of the top end of the seat back, the seat back, or a part of the vehicle body located behind the seat back. A disposed position of the at least one emergency locking retractor is adjustable according to the designs of the vehicles. 
     The two shoulder webbings  3 A,  3 A′ connected to the at least one emergency locking retractor  2 A,  2 A′ are passed through a top of the seat back and are extended downwardly. One of the two emergency locking retractors  2 A is connected to the first connecting hole  1121  of the first connecting portion  112  of the buckle assembly  10 A by a distal end of a corresponding one of the two shoulder webbings  3 A. The other one of the two emergency locking retractors  2 A′ is connected to the second connecting hole  2121  of the second connecting portion  212  of the tongue assembly  20 A by a distal end of a corresponding one of the two shoulder webbings  3 A′. The two emergency locking retractors  2 A,  2 A′ having the two shoulder webbings  3 A,  3 A′ are able to pull freely. When the vehicle is decelerated or braked in emergency, the shoulder webbings  3 A,  3 A′ can be locked by the two emergency locking retractors  2 A,  2 A′. 
     In the first embodiment and the second embodiment of the multi-point seat belt system A, the two lower webbings  5 A,  5 A′ of the two automatic locking retractors  4 A,  4 A′ are respectively and downwardly extended from two sides of a cushion of the seat. The lower webbing  5 A of one of the two automatic locking retractors  4 A is inserted through the first through hole  1131  of the first insertion portion  113  of the buckle assembly  10 A. A distal end of the lower webbing  5 A is connected to a lower fixing member  6 A and is disposed beside the cushion of the seat. The lower webbing  5 A′ of the other one of the two automatic locking retractors  4 A′ is inserted through the second through hole  2131  of the second insertion portion  213  of the tongue assembly  20 A. A distal end of the lower webbing  5 A′ is connected to another lower fixing member  6 A′ and is disposed beside the cushion of the seat. The lower webbing  5 A,  5 A′ of each one of the two automatic locking retractors  4 A,  4 A′ can be pulled, is retracted automatically to a suitable length for fitting the occupant, and then is locked. 
     As the second embodiment of the multi-point seat belt system A is in use, with reference to  FIGS. 9 and 12 , when the occupant sitting on the seat fastens the multi-point seat belt system A, the webbing locking device lA can be moved to a position adjacent to a center of a pelvis of the occupant by the occupant. When the webbing locking device  1 A is moving, the two shoulder webbings  3 A,  3 A′ and the two lower webbings  5 A,  5 A′ can be pulled and move to the suitable lengths automatically. The length adjustments of the two shoulder webbings  3 A,  3 A′ and the two lower webbings  5 A,  5 A′ are not done manually. The occupant can fasten the multi-point seat belt system A quickly and conveniently. 
     When the vehicle is tilted, decelerated or braked in emergency, the two shoulder webbings  3 A,  3 A′ are locked by the two emergency locking retractors  2 A,  2 A′ immediately, and the two lower webbings  5 A,  5 A′ are locked by the two automatic locking retractors  4 A,  4 A′. The shoulder webbings  3 A,  3 A′ and the lower webbings  5 A,  5 A′ are distributed around a body of the occupant and can fasten the occupant on the seat steadily for promoting the safety protection performance of the multi-point seat belt system A. 
     With reference to  FIGS. 1 to 2, and 13 to 16 , the structures of a third embodiment and a fourth embodiment of the multi-point seat belt system B and the structures of the first embodiment and the second embodiment of the multi-point seat belt system A are almost the same and all have the webbing locking device  1 A,  1 A′,  1 B,  1 B′, the emergency locking-retracting mechanism  9 , and the two automatic locking retractors  4 A,  4 A′,  4 B,  4 B′. The functions of the emergency locking-retracting mechanisms  9  and the automatic locking retractors  4 B,  4 B′ in the third embodiment and the fourth embodiment of the multi-point seat belt system B are respectively same to the functions of the emergency locking-retracting mechanisms  9  and the automatic locking retractors  4 A,  4 A′ in the first embodiment and the second embodiment of the multi-point seat belt system A. 
     With reference to  FIGS. 13, 14, 24, and 26 , in the third embodiment and the fourth embodiment of the multi-point seat belt system B, the emergency locking-retracting mechanism  9  is adapted to be disposed on the seat of the vehicle or the vehicle body. The emergency locking-retracting mechanism  9  has the at least one emergency locking retractor (ELR)  2 B,  2 B′ and the two shoulder webbings  3 B,  3 B′. The two shoulder webbings  3 B,  3 B′ are connected to the at least one emergency locking retractor  2 B,  2 B′ for being extracted, retracted, and locked automatically. With reference to  FIG. 13 , the amount of the at least one emergency locking retractor  2 B is one. The two shoulder webbings  3 B,  3 B′ are connected to each other to form a Y-shaped webbing for connecting the emergency locking retractor  2 B. With reference to  FIG. 14 , the amount of the at least one emergency locking retractor  2 B,  2 B′ is two. The two shoulder webbings  3 B,  3 B′ are respectively connected to the two emergency locking retractors  2 B,  2 B′. 
     With reference to  FIGS. 13, 14, 24, and 26 , the two automatic locking retractors  4 B,  4 B′ are adapted to be disposed on two sides or the outside of the seat in the vehicle. Each one of the two automatic locking retractors  4 B,  4 B′ has a lower webbing  5 B,  5 B′ being extracted, retracted, and locked automatically. 
     With reference to  FIGS. 13, 24, and 26 , the webbing locking device  1 B is connected between the two shoulder webbings  3 B,  3 B′ of the emergency locking-retracting mechanism  9  and the two lower webbings  5 B,  5 B′ of the two automatic locking retractors  4 B,  4 B′, and provides multiple fixing points distributed around the seat. The two shoulder webbings  3 BA,  3 B′ of the at least one emergency locking retractor  2 B,  2 B′ can be pulled freely. When the vehicle is decelerated or braked in emergency, the two shoulder webbings  3 B,  3 B′ can generate a locking function. The two lower webbings  5 B,  5 B of the two automatic locking retractors  4 B,  4 B′ can be pulled, are retracted automatically to a suitable length for fitting the occupant, and then are locked. 
     The difference between the first and second embodiments of the multi-point seat belt system A and the third and fourth embodiments of the multi-point seat belt system B is in the structure of the webbing locking device  1 A,  1 B, and the connecting way between the two shoulder webbings  3 A,  3 A′,  3 B,  3 B′ of the emergency locking-retracting mechanism  9  and the two lower webbings  5 A,  5 A′,  5 B,  5 B′ of the two automatic locking retractors  4 A,  4 A′,  4 B,  4 B′. 
     With reference to  FIGS. 13 to 16 , in the third and fourth embodiments of the multi-point seat belt system B, the webbing locking device  1 B has the buckle assembly  10 B, the tongue assembly  20 B, and two sliding members  30 B. The tongue assembly  20 B is selectively locked or unlocked with the buckle assembly  10 B. The two sliding members  30 B are respectively disposed in the buckle assembly  10 B and the tongue assembly  20 B, and respectively lock or unlock the two shoulder webbings  3 B,  3 B′ passing through the buckle assembly  10 B and the tongue assembly  20 B. 
     With reference to  FIGS. 13 to 18 , the buckle assembly  10 B has the buckle base  11  and the locking assembly  12 . The buckle base  11  is made of the rigid material or the metallic material, such as steel. The buckle base  11  has a body  111 , a first connecting portion  112 , and a first insertion portion  113 . The first connecting portion  112  and the first insertion portion  113  are formed on an end of the body  111 . The first connecting portion  112  is located below the first insertion portion  113  and has a first connecting hole  1121 . The first connecting hole  1121  is formed through the first connecting portion  112 . The locking assembly  12  is disposed on the body  111  of the buckle base  11 . The locking assembly  12  has the locking mechanism  121  and the pressing member  122 . The pressing member  122  can selectively drive the locking mechanism  121  to change the locked state to the unlocked state. The locking assembly  12  can be selected from the known product and will not be described herein. 
     With reference to  FIGS. 13 to 18 , the tongue assembly  20 B has the tongue base  21 . The tongue base  21  is the rigid base and is made of the rigid material or the metallic material, such as steel. The tongue base  21  has the tongue portion  211 , the second connecting portion  212 , and the second insertion portion  213 . The second connecting portion  212  and the second insertion portion  213  are formed on the end of the tongue portion  211 . The second connecting portion  212  is located below the second insertion portion  213 . The second connecting portion  212  has the second connecting hole  2121  formed through the second connecting portion  212 . The second insertion portion  213  has the second through hole  2131 . The second through hole  2131  is formed through the second insertion portion  213  and is the elongated hole. The tongue portion  211  of the tongue assembly  20 B can be selectively inserted into and is locked in the locking assembly  12  of the buckle assembly  10 B. When the pressing member  122  of the locking assembly  12  is pressed, the locking assembly  12  can release the tongue assembly  20 B. 
     With reference to  FIGS. 13 to 23 , one of the two sliding members  30 B is slidably inserted through the first through hole  1131  of the first insertion portion  113  of the buckle assembly  10 B and is able to move relative to the first insertion portion  113 . The other one of the two sliding members  30 B is slidably inserted through the second through hole  2131  of the second insertion portion  213  of the tongue assembly  20 B and is able to move relative to the second insertion portion  213 . 
     Each one of the two sliding members  30 B has a first side plate  32  having a top end, a second side plat  33 , and a base portion  31 . The second side plate  33  is opposite to the first side plate  32  at a spaced interval and has a bottom end. The base portion  31  is formed between the first side plate  32  and the second side plate  33  and has a through groove  311  and two walls  312 . The through groove  311  downwardly and inclinedly extends from the top end of the first side plate  32  to the bottom end of the second side plate  33 . The two walls  312  are both connected to the first side plate  32  and the second side plate  33 , and are located at two opposite sides of the through groove  311 , respectively. 
     With reference to  FIGS. 13 to 23 , in one of the two sliding members  30 B, the base portion  31  is inserted through the first through hole  1131  of the first insertion portion  113  of the buckle assembly  10 B. The first side plate  32  and the second side plate  33  are respectively located at the two opposite sides of the first insertion portion  113 . One of the two shoulder webbings  3 B is inserted through the first through hole  1131  of the first insertion portion  113  of the buckle assembly  10 B and the through groove  311  of a corresponding one of the two sliding members  30 B. In the other one of the two sliding members  30 B, the base portion  31  is inserted through the second through hole  2131  of the second insertion portion  213  of the tongue assembly  20 B. The first side plate  32  and the second side plate  33  are respectively located at two opposite sides of the second insertion portion  213 . The other one of the two shoulder webbings  3 B′ is inserted through the second through hole  2131  of the second insertion portion  213  of the tongue assembly  20 B and the through groove  311  of the other one of the two sliding members  30 B. The two sliding members  30 B respectively slide in a limited range in the first insertion portion  113  of the buckle assembly  10 B and a limited range in the second insertion portion  213  of the tongue assembly  20 B. With reference to  FIGS. 22 and 23 , the two shoulder webbings  3 B,  3 B′ passing through the buckle assembly  10 B and the tongue assembly  20 B can be locked or unlocked by the two sliding members  30 B, respectively. 
     With reference to  FIGS. 14 and 24 , in the webbing locking device  1 B, the buckle assembly  10 B further has a buckle outer shell  13 . The buckle outer shell  13  covers the buckle base  11  and the locking assembly  12 . The first connecting portion  112  of the buckle base  11 , the first insertion portion  113  having one of the two sliding members  30 B, and the pressing member  122  of the locking assembly  12  are exposed out of the buckle outer shell  13 . The tongue assembly  20 B further has a tongue outer shell  22 . The tongue outer shell  22  covers the tongue base  21 . The tongue portion  211  of the tongue base  21 , the second connecting portion  212 , and the second insertion portion  213  having the other one of the two sliding members  30 B are exposed out of the tongue outer shell  22 . 
     With reference to  FIGS. 14 and 25 , in the third embodiment and the fourth embodiment of the multi-point seat belt system B, the multi-point seat belt system B has a shoulder webbing connecting device  8 . The shoulder webbing connecting device  8  is detachable and is selectively disposed between the two shoulder webbings  3 B,  3 B′ for limiting a distance between the two shoulder webbings  3 B,  3 B′. The two webbing sheaths  80  are respectively and detachably disposed around the two shoulder webbings  3 B,  3 B′. The buckling assembly  81  is detachably connected between the two webbing sheaths  80 . The webbing sheaths  80  and the buckling assembly  81  can be selected from the known products and will not be described herein. 
     With reference to  FIGS. 13, 14, 24, and 26 , when the third embodiment and fourth embodiment of the multi-point seat belt system B are in use, taking the fourth embodiment of the multi-point seat belt system B for example, the two emergency locking retractors  2 B,  2 B′ are disposed on the top end of the seat back of the seat in the vehicle, or the back side of the top end of the seat back, or the seat back. The two shoulder webbings  3 B,  3 B′ of the two emergency locking retractors  2 B,  2 B′ can respectively detour a top side of the seat back and extend downwardly. The shoulder webbing  3 B of one of the two emergency locking retractors  2 B passes through the first insertion portion  113  of the buckle assembly  10 B and is disposed at a side of the cushion of the seat by the distal end thereof connected to a shoulder fixing member  7 B. The shoulder webbing  3 B′ of the other one of the two emergency locking retractors  2 B′ passes through the second first insertion portion  213  of the tongue assembly  20 B and is disposed at another side of the cushion of the seat by the distal end thereof connected to another shoulder fixing member  7 B′. 
     With reference to  FIGS. 14, 24, and 26 , in the fourth embodiment of the multi-point seat belt system B, the two automatic locking retractors  4 B,  4 B′ are respectively disposed on the two sides of the seat or disposed out of the seat. The two lower webbings  5 B,  5 B′ of the two automatic locking retractors  4 B,  4 B′ are respectively and upwardly extended from the two sides of the cushion. The lower webbing  5 B of one of the two automatic locking retractors  4 B is inserted through the first connecting hole  1121  of the first connecting portion  112  of the buckle assembly  10 B. The lower webbing  5 B′ of the other one of the two automatic locking retractors  4 B′ is inserted through the second connecting hole  2121  of the second connecting portion  212  of the tongue assembly  20 B. 
     With reference to  FIGS. 14, 24, and 26 , in the fourth embodiment of the multi-point seat belt system B, the two shoulder webbings  3 B,  3 B′ of the two emergency locking retractors  2 B,  2 B′ can be pulled freely. When the vehicle is decelerated or braked in emergency, the two shoulder webbings  5 B,  5 B′ generate the locking function. The lower webbing  5 B,  5 B′ of each one of the two automatic locking retractors  4 B,  4 B′ can be pulled, is retracted automatically to the suitable length for fitting the occupant, and then is locked. When the occupant sitting on the seat fastens the multi-point seat belt system B, the webbing locking device  10 B can be moved to the position adjacent to the center of the pelvis of the occupant by the occupant. When the webbing locking device  10 B is moving, the two shoulder webbings  3 B,  3 B′ and the two lower webbings  5 B,  5 B′ can be pulled and move to the suitable lengths automatically. The length adjustments of the two shoulder webbings  3 B,  3 B′ and the two lower webbings  5 B,  5 B′ are not done manually. The occupant can fasten the multi-point seat belt system B quickly and conveniently. 
     Moreover, after the occupant is seated on the seat, with reference to  FIGS. 14, 22, 24, and 26 , for adjusting the height position of the webbing locking device  1 B located on the two shoulder webbings  3 B,  3 B′, two hands of the occupant hold the buckle base  11  of the buckle assembly  10 B and the tongue base  21  of the tongue assembly  20 B respectively and instinctively. The first insertion portion  113  of the buckle base  11  moves relative to one of the two sliding members  30 B disposed on the first insertion portion  113  for unlocking one of the two shoulder webbings  3 B passing through the first insertion portion  113 . The second insertion portion  213  of the tongue assembly  20 B moves relative to the other one of the two sliding members  30 B disposed on the second insertion portion  213  for unlocking the other one of the two shoulder webbings  3 B′ passing through the second insertion portion  213 . The buckle base  11  of the buckle assembly  10 B and the tongue base  21  of the tongue assembly  20 B are pushed simultaneously. The buckle assembly  10 B and the tongue assembly  20 B can be steplessly adjusted to the suitable positions on the two shoulder webbings  3 B,  3 B′. 
     After two hands don&#39;t hold buckle base  11  of the buckle assembly  10 B and the tongue base  21  of the tongue assembly  20 B, the tension of the two shoulder webbings  3 B,  3 B′ can be applied to the buckle assembly  10 B and the tongue assembly  20 B respectively. The first insertion portion  113  of the buckle assembly  10 B moves relative to the corresponding one of the two sliding members  30 B for clipping and locking one of the two shoulder webbings  3 B automatically. The second insertion portion  213  of the tongue assembly  20 B moves relative to the corresponding one of the two sliding members  30 B for clipping and locking the other one of the two shoulder webbings  3 B′ automatically. 
     When the vehicle is tilted, decelerated or braked in emergency, in the fourth embodiment of the multi-point seat belt system B, the two shoulder webbings  3 B,  3 B′ are respectively locked by the two emergency locking retractors  2 B,  2 B′. The two lower webbings  5 B,  5 B′ are respectively tightened by the two automatic locking retractors  4 B,  4 B′. The shoulder webbings  3 B,  3 B′ and the lower webbings  5 B,  5 B′ are distributed around the body of the occupant and can fasten the occupant on the seat steadily for promoting the safety protection performance of the multi-point seat belt system B.