Abstract:
A vehicle occupant restraint system includes a seat belt webbing connected to a latch plate, wherein the latch plate is configured to be releasably connected to a buckle assembly in order to secure the webbing in a position capable of restraining the occupant. The buckle assembly includes a release button, a blocking component, a solenoid coupled to a connecting member positioned to engage the blocking component, and a solenoid actuator electrically connected to the solenoid. The blocking component is configured to engage the latch plate in order to connect the latch plate to the buckle assembly, and is configured to disengage from the latch plate in order to facilitate the release of the latch plate when the release button is depressed. When the solenoid actuator actuates the solenoid, the connecting member is configured to move to thereby change the position of the blocking component in order disengage the blocking component from the latch plate.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
     This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/071,549, filed May 5, 2008. The foregoing provisional application is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     This application relates generally to the field of vehicle occupant restraint systems. More particularly, this application relates to a seat belt system having a latch plate and buckle assembly configured to remotely release the latch plate while maintaining mechanical functionality for normal use. 
     Conventional seat belt systems for vehicles typically include a matable latch plate and buckle assembly configured to secure the vehicle occupant to a seat during rapid acceleration and deceleration of the vehicle. These systems may be found in front seats, rear seats, third seats, etc., or any combination thereof. 
     In the event of an emergency vehicle situation (such as a sudden stop, collision, rapid change of altitude, etc.) it may become necessary to release a seat belt from the buckle assembly remotely by a vehicle operator, other vehicle occupant, emergency personnel, etc., to facilitate the quick exit of occupants, especially those occupants who may require assistance with their seat belt. For example, in school buses, it may be difficult for a bus driver to both unbuckle all of the children in a bus and help them exit safely in an emergency. 
     Therefore, it is desirable for a seat belt system to include a remote latch release for use in the event of an emergency situation. The buckle assembly should maintain full mechanical functionality for use in all other situations or in the event of power failure. 
     It is also desirable that any additional components required to achieve the remote release functionality of the buckle assembly be integrated into the buckle in order to avoid creating a bulky mass that could result in occupant injury upon release. 
     It is also desirable that the additional components required to achieve the remote functionality of the buckle assembly be sized to allow the buckle assembly to be packaged in nearly all environments that currently use standard buckles. 
     It is also desirable that the system for remote release of the buckle remain generally deenergized when not in use in order to reduce heat generation during normal use of the buckle assembly. 
     SUMMARY 
     A vehicle occupant restraint system includes a seat belt webbing connected to a latch plate, wherein the latch plate is configured to be releasably connected to a buckle assembly in order to secure the webbing in a position capable of restraining the occupant. The buckle assembly includes a release button, a blocking component, a solenoid coupled to a connecting member positioned to engage the blocking component, and a solenoid actuator electrically connected to the solenoid. The blocking component is configured to engage the latch plate in order to connect the latch plate to the buckle assembly, and is configured to disengage from the latch plate in order to facilitate the release of the latch plate when the release button is depressed. When the solenoid actuator actuates the solenoid, the connecting member is configured to move to thereby change the position of the blocking component in order disengage the blocking component from the latch plate. 
     A motor vehicle having an occupant restraint system includes a plurality of seats, wherein the seats are configured to support seat occupants. A seat belt assembly is attached to at least one of the plurality of seats, wherein the seat belt assembly is configured to restrain the occupant. The seat belt assembly includes a seat belt webbing connected to a latch plate and a buckle assembly, wherein the latch plate may be configured to be releasably connected to a buckle assembly. The buckle assembly may be configured to include a release button, a blocking component, a solenoid coupled to a connecting member positioned to engage the blocking component, and a solenoid actuator electrically connected to the solenoid. The blocking component may be configured to engage the latch plate in order to connect the latch plate to the buckle assembly, and is configured to disengage from the latch plate in order to facilitate the release of the latch plate when the release button is depressed. When the solenoid actuator actuates the solenoid, the connecting member is configured to move to thereby change the position of the blocking component in order disengage the blocking component from the latch plate. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the description serve to explain principles of the invention. 
         FIG. 1  is a side view of an exemplary vehicle including a seat with a seat belt system according to an embodiment of the invention. 
         FIG. 2  is a perspective view of an exemplary vehicle seat including a seat belt system according to an embodiment of the invention. 
         FIG. 3  is a perspective close-up view of a vehicle seat including a seat belt system according to an embodiment of the invention. 
         FIG. 4  is a schematic view of an exemplary electrical system for the seat belt system according to an embodiment of the invention. 
         FIG. 5  is a top perspective view of a buckle assembly according to a first embodiment of the invention. 
         FIG. 6  is a side cross-sectional view of a buckle assembly according to a first embodiment of the invention in which the solenoid is deenergized. 
         FIG. 7  is a side cross-sectional view of a buckle assembly according to a first embodiment of the invention in which the solenoid is energized. 
         FIG. 8  is a top perspective view of a buckle assembly according to a second embodiment of the invention. 
         FIG. 9  is a side cross-sectional view of a buckle assembly according to a second embodiment of the invention in which the solenoid is deenergized. 
         FIG. 10  is a side-cross sectional view of a buckle assembly according to a second embodiment of the invention in which the solenoid is energized. 
     
    
    
     DETAILED DESCRIPTION 
     Referring generally to the FIGURES and specifically to  FIGS. 1-4 , a seat belt system is configured to allow a seat belt latch plate  101  to be remotely released from a buckle assembly  110  through an electrical signal while maintaining full mechanical functionality for normal use or in the event of power failure. The seat belt system can be used in any vehicle  10  which may have vehicle occupant seats  20  configured to include seat belts. The seat belt system includes a seat belt webbing  90  connected to a latch plate  101  and a buckle assembly  110  for securing the latch plate  101 . The buckle assembly  110  utilizes a blocking mechanism to secure the latch plate  101  when it is inserted into the buckle assembly  110 . The blocking mechanism can be any combination of buckle assembly components which releasably secure the latch plate  101  in the buckle assembly  110 . A vehicle occupant may then release the latch plate  101  from the buckle assembly  110  by utilizing the mechanical release mechanism or the remote release mechanism. The mechanical release mechanism utilizes a release button  114  in the buckle assembly  110 . The release button  114  alters the blocking mechanism so that the latch plate  101  is released from the buckle assembly  110 . The remote release mechanism utilizes an actuator switch  50  which may send an electrical signal to a solenoid in the buckle assembly  110 . The solenoid does not directly act on an ejector spring in the buckle assembly, but rather on one of the components of the blocking mechanism. Because the solenoid acts on the blocking mechanism, it is not directly in the load path for the forces placed on the seat belt during a crash. The seat belt loads never travel through the solenoid or other remote release mechanism components, which greatly improves the robustness of the seat belt assembly. The solenoid is configured to alter the blocking mechanism in a way so that the latch plate is released from the buckle assembly  110 . The solenoid is also configured so as not to interfere with the mechanical release mechanism. 
     As shown in  FIGS. 5-7 , the blocking mechanism comprises a lock bar  126  and a slider/latch bar  122 . The lock bar  126  may be located towards the top and the front of the buckle assembly  110 A, above where the latch plate  101  enters the buckle assembly  110 A. The lock bar  126  is preferably a metal cylindrically-shaped bar which connects opposing sides of two sides of a buckle frame  130 . The lock bar  126  in  FIGS. 5-7  is configured to remain static during the entry and release (mechanical or remote) of the latch plate from the buckle assembly  110 A. 
     The slider/latch bar  122  is located underneath the lock bar  126  and proximal to the release button protrusion  115  of the release button  114 . The slider/latch bar  122  has a slider portion  122 A and a latch bar portion  122 B. The slider portion  122 A is slidably attached to the top of the latch bar portion  122 B such that they form one blocking component. The slider portion  122 A is configured to slide across the top of the latch bar portion  122 B when the release button  114  acts on it. The slider portion  122 A is designed so that it may be wedged underneath the lock bar  126 . The slider portion  122 A has an upward extension  122 C at its rear. As shown in  FIGS. 5-7 , the upward extension  122 C of the slider portion  122 A includes a slot for receiving a portion of the connecting member  124 . The latch bar portion  122 B has a downward extension  122 D at its front. As shown in  FIGS. 6-7 , this downward extension  122 D of the latch bar portion  122 B is configured to mate with the latch plate  101  when the blocking mechanism  122  is pivoted downward by the insertion of the latch plate  101 . 
     As shown in  FIGS. 5-7 , the release button  114  may be located above where the latch plate  101  enters the buckle assembly  110 A. The release button  114  is roughly rectangular shaped and includes a release button protrusion  115 . The release button protrusion  115  is located at the rear of the release button  114 . When the release button  114  is depressed, the release button  114  slides along the buckle frame  130  and the release button protrusion  115  is configured to alter a blocking mechanism component. As shown in  FIGS. 5-7 , the release button protrusion  115  is configured to contact and move the slider portion  122 A of the slider/latch bar  122 . The release button  114  is connected to a button spring and guide bar  120  which connects the release button  114  to a blocking mechanism component. As shown in  FIGS. 5-7 , the button spring and guide bar  120  connect the release button  114  to the lock bar  126 . When the release button  114  is depressed, the button spring and guide bar  120  force the release button  114  back to its original position. 
     The solenoid preferably comprises an iron core and a plunger proximally located to the core. The iron core is preferably encircled with a casing containing electrically-conductive wiring. The solenoid is configured to receive an electrical signal when the actuator switch  50  is actuated. The solenoid is preferably deenegerized until it receives the electrical signal in order to minimize heat generation. When the solenoid receives the electrical signal, electrical current runs through wiring of the solenoid, creating a magnetic field in the interior of the solenoid. The magnetic field then causes the solenoid plunger to be attracted to or repelled from the iron core, depending on the type of magnetic field created. Alternative types of solenoids may be employed. For example, when the plunger is attracted towards the core, the solenoid is a pull-type solenoid. A pull-type solenoid  116  is shown in  FIGS. 5-7 . When the plunger is repelled away from the core, the solenoid is a push-type solenoid. A push-type solenoid  216  is shown in  FIGS. 8-10 . The solenoid is preferably located at the rear of the buckle assembly  110 . The plunger of the solenoid is coupled to a connecting member and acts on the connecting member when the solenoid is energized. 
     An example of a connecting member  124  is shown in buckle assembly  110 A in  FIGS. 5-7 . The connecting member  124  is a component which connects a solenoid  116  to a blocking mechanism component. The connecting member  124  can be made of any durable material, such as plastic or metal. As shown in  FIGS. 5-7 , an extension portion on the rear of the connecting member  124  is coupled to the solenoid  116 . The remaining portion of the connecting member  124  is generally J-shaped or U-shaped, having a flat portion  124 A and a hook portion  124 B. The flat portion  124 A of the connecting member  124  is inserted into a slot in the upward extension  122 C of the slider portion  122 A. The hook portion  124 B of the connecting member  124  then wraps around the uppermost point of the extension  122 C of the slider portion  122 A, and continues back towards the solenoid  116 . The shape of the connecting member  124  and the coupling between the connecting member  124  and the slider portion  122 A is important to allowing the buckle assembly to have both mechanical and remote release mechanisms. The slider/latch bar  122  can shift and pivot freely as needed when the mechanical release mechanism is utilized, while allowing the connecting member  124  to pull on the slider/latch bar  122  when the remote release mechanism is utilized. 
     Another exemplary connecting member  224  is shown in  FIGS. 8-10 . The rear of the connecting member  224  is coupled to a push-type solenoid  216 . The connecting member  224  as shown in  FIG. 8  is generally U-shaped, having two bracket portions which extend along the exterior of buckle frame  130 . The connecting member  224  could also be placed in the buckle assembly  110 B such that it is located above the other buckle assembly  110 B components. The two bracket portions of the connecting member  224  are connected to opposite sides of the lock bar  226 . Any one of the many fastening mechanisms well known to those skilled in the art may be used to couple the connecting member  224  to the solenoid  216  or to couple the connecting member  224  to the lock bar  226 . The shape of the connecting member  224  and the coupling between the connecting member  224  and the lock bar  226  is important to allowing the buckle assembly to have both mechanical and remote release mechanisms. The connecting member  224  may push the lock bar  226  as needed when the solenoid  226  is energized during operation of the remote release mechanism, while allowing the lock bar  226  to remain static when the mechanical release mechanism is utilized. 
     The connecting member in the buckle assemblies  110  allows the buckle assemblies  110  to maintain the ability to be used in a traditional manner, with a spring loaded release button, even though the buckle assemblies  110  include a solenoid, thereby unaffecting normal buckle function. The connection between the solenoid and a component of the blocking mechanism ensures that the structural load path within the buckle is unaffected by the presence of the solenoid. The manual release mechanism can be used at any time, even simultaneously with the remote release mechanism, without interference from the remote release mechanism. 
     As shown in  FIGS. 1-2 , a vehicle  10  may be equipped so that a passenger seat  20  is equipped with a seat belt system including buckle assemblies  110 . The driver seat and/or all of the passenger seats may be equipped with seat belt systems including buckle assemblies  110 . Thus, in case of an emergency, the latch plates  101  may be released from the buckle assemblies  110  remotely by the vehicle driver, e.g., to facilitate the quick exit of vehicle occupants. The remote release capability is especially useful for vehicle occupants who may otherwise need special assistance with unbuckling their seat belts. For example, it may be very difficult for a bus driver to both unbuckle all of the children in a school bus and help them exit safely in an emergency. Other potential vehicle applications include automobiles and mass-transit vehicles, such as motor coaches, buses, trains, airplanes, etc. 
     As shown in  FIGS. 3-4 , the latch plate remote release mechanism may be controlled by an actuator switch  50 , which may be located near the vehicle&#39;s driver&#39;s seating position (as shown in  FIG. 1 ). The actuator switch  50  may provide for directly energizing a solenoid in the buckle assembly  110  (e.g., via a simple circuit closure), or provide an actuation signal to a electronic control unit  70  configured to receive an input from the actuator switch  50 . There may be an electronic control unit  70  for each seat (in which case, the actuator switch  50  provides an actuation signal to each electronic control unit  70 ), or just one electronic control unit  70  for all seats. The electronic control unit  70  may contain a microprocessor  75  configured to send an appropriate signal to the solenoid  116  in the buckle assembly  110 , as shown in  FIG. 4 . The electronic control unit  70  may be located on the seat  20  (as shown in  FIG. 3 ) or any other suitable place in the vehicle. The microprocessor  75  may send a signal to another microprocessor, which may be located on seat  20  or in the buckle assembly  110 . The signals transmitted in the system may be carried by any suitable method including, for example, through wires  80  (as shown in  FIGS. 3-4 ) or wirelessly (e.g., “Bluetooth” communication). Wires  80  may utilize MAYBUS communication, a simple current pulse, etc. 
     Referring to  FIGS. 5-7 , a first embodiment  110 A of a buckle assembly is shown. When a latch plate  101  is inserted into the buckle assembly  110 A, a blocking mechanism secures the latch plate. In  FIGS. 5-7 , a slider/latch bar  122  in conjunction with lock bar  126  performs this blocking mechanism function. When the latch plate  101  is inserted into the buckle assembly  110 A, the slider/latch bar  122  rotates downwards towards the bottom of the buckle frame  130  and simultaneously shifts towards the release button  114 . The downward extension  122 D of the latch bar portion  122 B is inserted into a slot of the latch plate  101  and contacts the bottom of the buckle frame  130  so as to secure the latch plate  101  in the buckle assembly  110 A. The latch bar portion  122 B is held in place because the slider portion  122 A of the slider/latch bar  122  is wedged underneath the lock bar  126  when the slider/latch bar  122  rotates downwards. 
     Buckle assembly  110 A includes a release button  114  that mechanically releases the latch plate from the buckle assembly  110  without use of or interference from the solenoid  116 . When the release button  114  is depressed, protrusion  115  of release button  114  contacts the slider portion  122 A and applies a force such that the slider portion  122 A slides along the latch bar portion  122 B in a direction away from the release button  114 . The shift in position must be sufficient to translate the slider portion  122 A past the edge of the lock bar  126 . Once the slider portion  122 A is no longer wedged underneath the lock bar  126 , the slider/latch bar  122  rotates away from the bottom of the buckle frame  130  such that latch bar portion  122 B no longer secures the latch plate  101  in the buckle assembly  110 A. The movement and rotation of the slider/latch bar  122  causes an ejector spring  128  to eject the latch plate  101  out of the buckle assembly  110 A. 
     Additionally, electrical release of the latch plate  101  from the buckle assembly  110 A is possible using solenoid  116 . In  FIGS. 5-7 , solenoid  116  is a pull-type solenoid. When the solenoid  116  is actuated, the plunger of solenoid  116  pulls on a connecting member  124  coupled to the solenoid  116  such that the connecting member  124  shifts away from the release button  114 . When the connecting member  124  is pulled by the solenoid  116 , the connecting member  124  pulls the slider portion  122 A of the slider/latch bar  122 , allowing the slider portion  122 A to become unwedged from the lock bar  126 . The slider/latch bar  122  then rotates upwards away from the bottom of the buckle frame  130 . This movement of the slider/latch bar  122  causes the downward protrusion  122 D of the latch bar portion  122 B to release the latch plate  101  such that the latch plate  101  may be ejected from the buckle assembly  110 A by ejector  128 . 
       FIG. 6  illustrates the first embodiment  1110 A of the buckle assembly when the solenoid  116  is de-energized (not actuated). The user may push the release button  114  such that the protrusion  115  contacts the slider portion  122 A. The slider portion  122 A then travels a short distance (preferably approximately 5 mm) and is released from below lock bar  126 . The shape of the connecting member  124  allows the slider portion  122 A to shift when it is contacted by the protrusion  115  of the release button  114  without interference from the connecting member  124  or the solenoid  116 . 
       FIG. 7  illustrates the first embodiment  110 A of the buckle assembly when the solenoid  116  is energized (actuated). When solenoid  116  is energized, the solenoid  116  pulls on the connecting member  124 . Connecting member  124  is shaped so that the connecting member  124  pulls the slider portion  122 A when the solenoid  116  is actuated. The slider portion  122 A is pulled such that it is released from below lock bar  126 . The slider/latch bar  122  may then freely pivot to release the latch plate  101  from the buckle assembly  110 A. 
       FIGS. 8-10  illustrate a second embodiment  110 B of a buckle assembly. The buckle assembly  110 B contains many of the same components as the buckle assembly  110 A, such as a release button  114 , ejector  128 , and buckle frame  130 . As in buckle assembly  110 A, buckle assembly  110 B allows a latch plate  101  to be remotely released while maintaining normal mechanical release functionality. In buckle assembly  110 B, a connecting member  224  is coupled to a solenoid  216  and a lock bar  226 , such that the solenoid  216  acts on the lock bar  226  through the connecting member  224  when the solenoid  216  is actuated. 
     When a latch plate  101  is inserted into the buckle assembly  110 B, a blocking mechanism secures the latch plate. In  FIGS. 8-10 , a slider/latch bar  222  in conjunction with lock bar  226  performs this blocking mechanism function. When the latch plate  101  is inserted into the buckle assembly  110 B, the slider/latch bar  222  rotates downwards towards the bottom of the buckle frame  130  and simultaneously shifts towards the release button  114 . The latch bar portion  222 B is inserted into a slot of the latch plate  101  and contacts the bottom of the buckle frame  130  so as to secure the latch plate  101  in the buckle assembly  110 B. The slider/latch bar  222  is held in place because the slider portion  222 A is wedged underneath the lock bar  226  when the latch plate  101  is inserted into the buckle assemble  110 B. 
       FIG. 9  illustrates the second embodiment  110 B of the buckle assembly when the solenoid  216  is de-energized (not actuated). The release button  114  may be used to mechanically release the latch plate  101  from the buckle assembly  210  without use of or interference from the solenoid  216 . When the release button  114  is depressed, protrusion  115  of release button  114  contacts the slider portion  222 A and applies a force such that the slider portion  222 A shifts in position away from the release button  114 . The shift in position must be sufficient to translate the slider portion  222 A past the edge of the lock bar  226 . Once the slider portion  222 A is no longer wedged underneath the lock bar  226 , the slider/latch bar  222  rotates away from the bottom of the buckle frame  130  such that the downward extension  222 D of the latch bar portion  222 B no longer secures the latch plate  101  in the buckle assembly  110 B. The movement and rotation of the slider/latch bar  222  causes the ejector spring  128  to eject the latch plate  101  out of the buckle assembly  110 B. 
       FIG. 10  illustrates the second embodiment  110 B of the buckle assembly when the solenoid  216  is energized (actuated). When solenoid  216  is actuated, the solenoid  216  pushes the connecting member  224 . The connecting member  224  is shaped so that the connecting member  224  pushes the lock bar  226  along the lock bar slot  227  towards the release button  114  when the solenoid  216  is actuated. This movement of the lock bar  226  allows the slider portion  222 A to become unwedged from the lock bar  226 . The slider/latch bar  222  may then shift away from the release button  114  and pivot upwards away from the bottom of the buckle frame  130 . This pivoting is configured to thereby cause the ejector  128  to eject the latch plate  101  from the buckle assembly  110 B. 
     In some seat belt and buckle assemblies, the remote release mechanism is incorporated into or onto a buckle mounting stalk or strap. The mass of the disengaging portion in these assemblies is large enough to possibly cause serious injury. In seat belt and buckle assemblies of the embodiments of the invention, the remote release mechanism is incorporated into the buckle assembly such that the mass of the disengaging portion is minimized. Only the latch plate itself need be retracted by the seat belt retractor. 
     The solenoid buckle concept solves problems related to electrical consumption and heat generation. Because the solenoid is no longer in the mechanical load path, it does not need to be actuated to hold the latch plate in place during normal use, therefore, it requires zero current unless it is being actuated to release the latch plate, and as a result, it produces no heat unless it is being activated. 
     Another benefit of the solenoid buckle concept, is the amount of current required. By designing the solenoid actuation strategy such that only blocking mechanism component needs to be moved, the force requirement for the solenoid is minimized. This allows the size of the solenoid to be minimized. By minimizing the size of the solenoid, the increase in buckle size is also minimized. This allows the buckle to be packaged in nearly all environments that currently use standard buckles. 
     By designing the remote release mechanism to be installed without re-tooling the buckle frame or internal buckle components (except for modifying the lock bar or slider, which is formed by a very simple tool), modularity and shared components for base and solenoid buckles is maximized. The buckle assemblies of the embodiments of the invention also include fewer components and have a lower cost of the core components then other seat belt and buckle assemblies incorporating a solenoid. 
     It is important to note that the construction and arrangement of the seat belt system as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter disclosure herein. For example, elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present application. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments.