Abstract:
The method and device of this invention immobilizes a person in a secure, upright restraint system in a Police vehicle. It can be easily and safely applied by public safety officers including police or other law enforcement personnel and medical personnel to secure a person against undesired movement while maintaining them in an upright, sitting position which leaves the diaphragm free for natural, unrestrained breathing movement. The asphyxia-preventing restraining device comprises an ALR/ELR retractor. The ALR/ELR retractor comprises a shoulder harness having a pair of seat belt buckles, which significantly reduce the possibilities of injuries to police officers.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a seat belt system for restraining a prisoner in a law enforcement vehicle.  
         BACKGROUND OF THE INVENTION  
         [0002]    A seat belt system for restraining a seated prisoner in a law enforcement vehicle ordinarily includes seat belt webbing, a seat belt buckle, and a seat belt retractor. A locking tongue on the webbing is releasably lockable in the buckle when the webbing has been extracted from the retractor and moved to a position in which shoulder and lap belt sections of the webbing extend across the prisoner. If the vehicle experiences a crash, a locking mechanism in the retractor blocks further extraction of the webbing. The webbing then restrains movement of the prisoner to protect the prisoner from a forceful impact with parts of the vehicle as a result of the crash.  
           [0003]    Often however, seat belts in police vehicles are simply not used. Due to the location of the belt system within a police vehicle, with the retractor mounted outboard of the prisoner and the buckle is positioned inboard of the prisoner. Police officers are under considerable risk of injury should they belt the prisoner. Injuries to the police officer can be caused by the prisoner biting, kicking, or head butting the police officer while the officer reaches over the prisoner to buckle him. As such, the belt in police vehicles are rarely used. As a result, a significant liability risk exists for municipalities which may be found responsible for injuries caused to a prisoner during a vehicle accident.  
           [0004]    Seat belt retractors fall into two broad categories. The first being an emergency locking retractor (ELR) which is activated only during an emergency to prevent protraction of the seat belt (webbing) wound about a spool of the retractor. This type of retractor includes various known sensors such as a web sensor with initiates the locking of the spool when the webbing is pulled at a rate above a designated level and a vehicle or inertia sensor sensitive to levels of vehicle deceleration to bring the spool into a locked condition. The second type of retractor is one which is brought into a locked condition after a determinable length of webbing have been protracted. Once this length of webbing has been protracted the retractor spool is automatically in its locked condition preventing further protraction of the webbing, this type of retractor is often referred to as an automatic locking retractor (ALR). The ALR retractor is reset once the webbing is fully retracted upon the spool. The ALR function has also been incorporated into an ELR retractors. This type of retractor includes a mode switching mechanism to switch the retractor from operating as an ELR to one that operates as an ALR retractor.  
           [0005]    This mode switching mechanism can take many forms such a feeler bar that rides upon the webbing coiled upon the spool. As the webbing is protracted the feeler bar rotates inwardly and at some angle, indicative of an amount of webbing protracted from the retractor the feeler bar causes a lock pawl to be moved into engagement with the lock teeth of the retractor. A more complex mode switching mechanism can be realized using a series of gears which rotates with the spool and at a predetermined position of one or more of these gears activates a lever to cause a lock pawl to engage a lock teeth of the retractor.  
           [0006]    This ELR/ALR retractor operates as an ELR retractor during an emergency and acts as an ALR once the seat belt webbing has been protracted a determinable length. A retractor with an ALR feature has proven useful in securing a child seat to the vehicle seat. After the child seat is in place upon the vehicle seat, the webbing is fully protractor from the retractor activating the mode switching mechanism. After the latch plate (also referred to as a tongue) is secured into its buckle the webbing is released and rewound into the retractor by its rewind spring. Once this occurs the webbing is pulled tight about the child seat and since the retractor is now in its ALR mode of operation the webbing is prevented from protracting during an emergency and as such the child seat is held securely upon the seat.  
         SUMMARY OF THE INVENTION  
         [0007]    In accordance with the present invention, a prisoner restraint system for a law enforcement vehicle restrains the seated prisoner&#39;s movement. The system restrains kicking movement by restraining movement of the prisoner&#39;s feet upward from positions resting on the vehicle floor, and also by restraining forward movement of the prisoner&#39;s feet. The system includes seat belt webbing, a seatbelt retractor, a first and second seat belt buckles, and a seat belt locking tongue, and has an engaged condition in which the tongue is interlocked with the first seat belt buckle to position the seatbelt in a position convenient for an officer&#39;s use and in the second buckle to restrain the prisoner.  
           [0008]    A primary object of the present invention is to provide an ALR/ELR seat belt retractor which has a mode switching mechanism, the mode switching of which can be used as a means to control the movement of a prisoner is a vehicle seat. A further object of the invention is to provide a safety restraints system that has a switch or sensing means which will detect the change of operational mode from the ELR mode to ALR mode, indicative of the fact that the webbing has been secured about a prisoner seat and provide a signal which will be used to vary the output of a lamp. Other objects, features, and advantages will become apparent from the following description and appended claims.  
           [0009]    Accordingly the invention includes a seat belt retractor having a mode switching mechanism capable of transforming the retractor to operate as an ALR or ELR retractor. The system provides a center mounted seatbelt retractor and a pair of seatbelt buckles. The first buckle is placed in a forward location in the vehicle compartment. The second buckle is placed in a location adjacent the vehicle seat. A sensing means capable of detecting the mode of operation of the retractor and to provide a signal, which can be used to modify the output of a warning lamp. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, wherein:  
         [0011]    [0011]FIG. 1 is a perspective view of the seatbelt system of the present invention in a police vehicle;  
         [0012]    [0012]FIG. 2 is a top view of apparatus of FIG. 1 in a police vehicle;  
         [0013]    [0013]FIGS. 3 and 4 represent a schematic views of other apparatus of the present invention; and  
         [0014]    [0014]FIG. 5 is a seatbelt retractor according to the teachings of the present invention.  
     
    
     DESCRIPTION OF PREFERRED EMBODIMENT  
       [0015]    An apparatus  10  comprising a preferred embodiment of the present invention is shown in FIG. 1. The apparatus  10  includes vehicle occupant restraint systems  12  for a rear seat  16  of a vehicle  18 . The vehicle  18  is a law enforcement vehicle such as an automobile, truck, van, or the like which is used to transport prisoners. The first restraint system  12  is a threepoint seat belt system for restraining an occupant of the seat  16  upon the occurrence of a vehicle crash. Accordingly, the restraint system  12  can continuously restrain a seated prisoner  17  so that the prisoner can move within the vehicle causing damage to himself, the adjacent door, window, front seat, or security grill.  
         [0016]    The restraint system  12  includes seat belt webbing  30  and a seat belt retractor  32  for the webbing  30 . As shown schematically in FIG. 2, the retractor  32  has a spool  34  upon which the webbing  30  is wound. A rewind spring  36  biases the spool  34  to rotate in a winding direction. The webbing  30  is movable back and forth between a fully retracted position and a fully extracted position upon winding and unwinding of the webbing  30  on the spool  34 .  
         [0017]    The first restraint system  12  further includes a seat belt locking tongue  40  and a first seat belt buckle  42 . The tongue  40  is preferably slidable along the length of the webbing  30 , and is releasably lockable in the first buckle  42 . The buckle  42  is anchored directly to the seat  16 , or directly to the vehicle floor  44 , in a known manner. The second buckle  43  is placed at the adjacent door&#39;s b-pillar  45 , front seat, or security grill.  
         [0018]    When the webbing  30  is in a first position, it extends upward from the from the retractor  32  to the second buckle  43  and then to the an anchor  46 , as shown in FIG. 1. The anchor  46  fixes the webbing  30  to the seat  16  or to the floor  44  in a known manner. When the webbing  30  is in the second position, shown in FIG. 2, it is extracted from the retractor  32  sufficiently to enable the tongue  40  to reach the first buckle  42 . A shoulder belt section  50  of the webbing  30  then extends across the seat  16  from the retractor  32  to the tongue  40 . A lap belt section  52  of the webbing  30  extends across the seat  16  from the anchor  46  to the tongue  40 .  
         [0019]    The rewind spring  36  in the retractor  32  is stressed as the spool  34  rotates in an unwinding direction when the webbing  30  is being extracted from the retractor  32  and the tongue  40  is being moved toward the buckle  42 . When the tongue  40  is released from the buckle  42 , the rewind spring  36  rotates the spool  34  in the winding direction to retract the webbing  30  into the retractor  32 , and thereby to move the webbing  30  back to the fully retracted position.  
         [0020]    The retractor  32  further includes a locking assembly  60 . The locking assembly  60  blocks further extraction of the webbing  30  when the webbing  30  is required to restrain the occupant of the seat  16 . Preferably, the locking assembly  60  includes both an emergency locking mechanism  62  and an automatic locking mechanism  64 . The emergency locking mechanism  62  blocks unwinding rotation of the spool  34  in response to an emergency condition such as, for example, vehicle roll-over, sudden vehicle deceleration, or sudden extracting movement of the webbing  30 . The automatic locking mechanism  64 , which is sometimes referred to as a cinch mechanism, continuously blocks unwinding rotation of the spool  34 . Such an automatic locking mechanism may be actuated in response to extraction of the webbing  30 , locking of the tongue  40  in the buckle  42 , or any other condition indicating that an occupant of the seat is wearing the webbing  30  for protection upon the occurrence of a vehicle crash.  
         [0021]    When the first webbing section  82  is in its first retracted position, as shown in FIG. 1, it preferably extends outward from beneath the seat  16  only far enough for the tongue  80  to be easily accessible to a law enforcement officer reaching into the vehicle  18  across a seated prisoner. When the first webbing section  80  is in the extracted position shown in FIG. 2, it extends outward from beneath the seat  16  sufficiently for the tongue  80  to be locked in the buckle  84  at the end of the second webbing section  86 .  
         [0022]    In accordance with a particular feature of the present invention, the first buckle  42  is located on the outboard side of the seated prisoner  17  when the restraint system  12  is in the engaged condition of FIG. 4. This ensures that the first buckle  42  is easily accessible to a law enforcement officer reaching into the vehicle  18  to unlock the tongue  80  from the first buckle  42 . FIG. 5 is illustrative of an ELR/ALR retractor  28  with a mode changing mechanism  22  shown in U.S. Pat. No. 4,811,912 which is incorporated herein by reference. This retractor  32  includes a gear mechanism  64 , which rotates as the webbing is extracted from the retractor  32 . At a predetermined position, a lever-ratchet  8  of the mechanism  22  is caused to change position thus initiating a change in the mode of operation of the retractor. FIG. 5 also shows a sensing means  60  positioned proximate to the level  8  to detect this change in position of the lever  8  (which is indicative of the change in operating mode from its ELR mode to its ALR mode).  
         [0023]    The following describes the operation of the invention. The seatbelt is placed into its first position by locking the tounge  80  into the first buckle  42 . The Webbing of the retractor is extended. As the webbing is protracted the retractor spool rotates moving the gears of the mode switching mechanism to the point the ALR mechanism  1  is engaged. The prisoner  17  is first placed on the vehicle seat  16 . As the webbing is protracted the retractor spool rotates moving the gears of the mode switching mechanism. With the webbing extended the lever  8  is caused to move placing the retractor  32  in its ALR mode of operation. Thereafter the webbing is released and is rewound upon the retractor spool drawing the webbing  30  tightly. The tounge  80  is released from the first buckle and inserted into the second buckle  1 . Thereafter the webbing is again released and is rewound upon the retractor spool drawing the webbing  29  tightly around the prisoner  17 . Optionally, the movement of the lever  8  is sensed by the switch mean  60  and communicated to and used by the control unit  29  to display a light visible to the police officer showing the status of the system.  
         [0024]    From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.