CROSS REFERENCE TO RELATED APPLICATIONS 
     Not Applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates in general to compartment door latches in automotive vehicles, and, more specifically, to systems, methods, and devices for preventing a glove box door from opening in an impact. 
     Injury from a crash event may be mitigated by active bolsters, padding, and/or airbags located at the glove box. In mitigating an impact, it is beneficial for the glove box door to remain closed and latched during, and immediately following, the impact. 
     In frontal impact crashes, a passenger&#39;s knees may impact the glove box door and force it to deform. Likewise, deformation may occur due to airbag or bolster expansion forces. This deformation, which is centered on the inner door where the latch is attached, sometimes causes the latch rods to retract and may potentially allow the glove box door to open. In many glove box door latch systems, the mechanism for maintaining the glove box in a closed position may be detrimentally affected by bolster or airbag deployment, by sudden passenger contact, or by other forces during a crash. 
     Accordingly, there is a need for improved devices, methods, and systems for maintaining the glove box door in a closed configuration during automobile collisions. 
     SUMMARY OF THE INVENTION 
     The present invention uses one or more locking plates to impede movement of a latch rod immediately following an impact and to strengthen the glove box door against either bowing or falling open. An impact event induces a mechanical interlock or lock plate to engage the latch rod mechanism to arrest movement. The force of the collision, passenger contact, or bolster deployment impels the lock plate into the locked configuration, thereby preventing the glove box door from unlatching. 
     In one aspect of the invention, an active glove box bolster system for a vehicle comprises an instrument panel housing defining a door space. A glove box door comprises latching system having a longitudinally-movable latch rod. A striker is provided on the housing for receiving the latch rod in a pocket between a front wall and a rear wall. The front wall slidably engages a sloped end of the latch rod during closing of the door to retract the latch rod until it enters the pocket. The latching system includes at least one interlock element along the length of the latch rod. Upon impact, the interlock element engages to resist movement of the latch rod in response to a bolster deployment force or a force against the door in a direction to push the door through the door space. 
     In accordance with the foregoing aspects of the invention, exemplary methods, systems, and structures are provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a glove box door system in a vehicle interior. 
         FIG. 2  is a top view of a glove box knee bolster system before a crash. 
         FIG. 3  is a top view of a prior art glove box knee bolster system during a crash. 
         FIG. 4  is a perspective view of the receptacle side of a glove box door. 
         FIG. 5  is a vertical cross-sectional view of an un-deployed active glove box system showing a door back panel carrying the latch rod and locking plate. 
         FIG. 6  is a vertical cross-sectional view of an active glove box system showing bolster deployment and locking plate activation. 
         FIG. 7  is a vertical cross-sectional view of an un-deployed active glove box system showing a locking plate with a tab feature. 
         FIG. 8  is an internal, plan view of a door back panel with latch rods and coupler. 
         FIG. 9  is an internal, plan view of a door back panel with a locking plate mounted at the coupler. 
         FIG. 10  is a perspective view of a locking plate mounted at the coupler. 
         FIG. 11  is a horizontal cross-sectional view of an active glove box system showing a door back panel carrying the latch rods together with the locking plate. 
         FIG. 12  is a simplified horizontal cross-sectional view of an alternate embodiment of the locking plate with pin-and-hole interlock elements. 
         FIG. 13  is a simplified horizontal cross-sectional view of an alternate embodiment of the locking plate with slot or notch and flange interlock elements. 
         FIG. 14  is a simplified horizontal cross-sectional view of an alternate embodiment of the locking plate with bracket leg and slot interlock elements. 
         FIG. 15  is a simplified horizontal cross-sectional view of an alternate embodiment of the locking plate with hole and pin interlock elements for a glove box door without an active bolster. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Active bolsters are integrated into glove box doors as a safety feature. An active bolster is a vehicle occupant protection device with a gas-inflatable bladder to absorb impacts and reduce injury to occupants during a crash. Active bolsters deploy in a vehicle crash to cushion the impact force of an occupant against an interior panel of the vehicle. As opposed to air bag cushions, which emerge from behind various openings upon inflation, active bolsters use the interior trim surface itself to expand upon sensing a crash event to absorb an occupant impact and dissipate energy by venting an inflation gas. 
     The bolster has an expandable hollow chamber typically formed by bonding a vehicle interior-facing front trim wall section and a rear bladder section. The front and rear sections may be attached around the periphery to join the two sections forming the chamber. The rear bladder is usually attached to a reaction surface or rear panel structural support. 
     When incorporating an active bolster into the door for a glove box or other storage compartment, the inside back plate of the door acts as a reaction surface which is relatively unmovable to the inflating bladder and the front panel pushing outward, toward the vehicle occupant (instead of into the storage compartment). The door back plate typically spans the opening so that the edges of the door overlap with the instrument panel or compartment frame in order to stop the door movement at a closed position. 
     The rear panel or back plate provides a supporting reaction surface and is joined to the internal bladder structure by attachment points or weld protrusions on the internal bladder structure, and corresponding attachment points or weld pads provided on the rear panel. 
     It is desirable to fabricate the back plate from a moldable thermoplastic for low cost, low weight, and easy attachment to the bladder wall—such as by hot plate welding. One potential problem with such a reaction wall is that it may have sufficient flexibility to bend during deployment of the bolster or during the impact of a passenger against the front panel. The bowing can result in compromised passenger restraint force, impaired bolster functionality, and unlatching of the glove box door. 
     In the normal course of operation, the glove box door, incorporating an active bolster in a non-inflated condition, opens and closes by rotating about a hinge. The hinge is integrally formed on the rear panel and rotatably attaches to the instrument panel. The glove-box door is releasably retained in the closed position by a latch mechanism provided in a latch housing of the rear panel. The latch mechanism cooperates with one or more latch apertures or striker pockets on the instrument panel or dashboard. 
     In a vehicle collision, the latch system may be presented with forces potentially causing loss of contact between the latch rod ends and the striker pockets. The cause of the loss of contact may be attributed to the glove box door deformation. Deformation of the door during impact and bolster deployment may cause bending about the centerline and pulling the latch rods in, and out of the striker pocket, because of the curved length exceeding the initial straight length. Loss of contact may also occur by sliding of the sloped ends of the rods against the rear walls of the strikers. One of the rods striking the back of the striker pocket may force it to be pushed in, causing the other rod to also retract because the latch rods are coupled together. Loss of contact may result in uncontrolled latch retraction leading to submarining or to the glove box door opening during inflation or impact. To prevent uncontrolled latch rod retraction, the collision force or bolster deployment impels the locking plate to arrest movement of the latch rods. 
     Referring now to  FIG. 1 , an instrument panel system  10  of an automotive vehicle includes an active glove box system  11  which includes a push button latch mechanism  12  which may be activated to open glove box system  11  to access a storage bin. Active glove box system  11  inflates to receive a passenger&#39;s knees  13  during a crash event in order to mitigate forces applied to the knees and body of the passenger. 
     As shown in  FIGS. 2 and 3 , system  11  includes a back panel  14 , a trim panel  15  and a bladder wall  16  for inflating during a crash event using gas supplied by an electronically-triggered inflator when a crash event is detected. A door frame or surround  17  includes striker pockets  19  for receiving latch rods  18  which extend from each lateral side of door back panel  14 .  FIG. 3  shows an exaggerated deformation of back panel  14  during an impact. The bending may result in the release of the latch rods  18  from the pockets  19 . 
     Turning now to  FIGS. 4-7 , the active bolster comprises a rear panel  14 , an internal inflatable bladder  16 , an inflation device  27 , and a front trim panel  15 . The bladder  16  may have a pleated (i.e., accordion-like) region that straightens out during inflation. The inflatable bladder  16  is welded or joined to the front trim panel around or near the perimeters of each of the bladder  16  and front trim panel  15  to form an inflatable hollow chamber  23 . 
       FIGS. 4, 5 and 7  show an embodiment of a glove-box door with a latch system and an active bolster in a pre-deployment, non-inflated condition.  FIG. 4  is a perspective view of the receptacle side of a glove box door, showing the rear side of the back panel  14  and a pocket-engaging end of the latch rod  18   a.    
       FIG. 5  is a vertical cross-sectional view of a closed and undeployed active glove box system. The glove box system  11  is mounted in the instrument panel  10  and provides a storage bin or receptacle  32 . A lower portion of the door back panel  14  attaches to the instrument panel  10  at a hinge. An upper portion of the door back panel  14  attaches to the instrument panel  10  by the latch system housed in a latch housing  34  portion of the back panel  14 . The door back panel  14  supports the latch rod coupler  24  and locking plate  30 . The bladder wall  16  is attached to the back panel  14  at one or more attachment points  26 . In the embodiment shown, the bladder also supports the inflation device  27 . The bladder wall  16  is attached to the trim panel near the periphery of the rear side of the trim panel  15 . The trim panel  15  front surface faces the passenger compartment. 
       FIG. 6  is a vertical cross-sectional view of an active glove box system showing bolster deployment and locking plate activation.  FIG. 6  shows deployment of the active bolster caused by inflating chamber  23  with gas from an inflator  27 . Since the back panel  14  is relatively stable, it functions as a reaction surface, and trim panel  15  moves forward into the passenger compartment during deployment. Because the inflating flexible bladder wall  16  pushes outward in all directions, the bladder wall  16  presses the locking plate  30  rearward, towards the latch system  28 , during inflation. The narrow tolerance between the locking plate  30  and an interfacing part of the latch system  28  allows the locking plate to lodge against a portion of the latch system  28 , quickly and tightly, thereby creating an interlock and arresting movement of the latch rods. 
     In the embodiment depicted in  FIGS. 5 and 6 , a portion of the bladder wall, before deployment, is positioned directly in front of the locking plate. In some embodiments the bladder wall is spaced about 1 mm from the locking plate. In some embodiments the bladder wall rests directly against the locking plate. In some embodiments the bladder wall is spaced about 0-3 mm from the locking plate. 
       FIG. 7  shows a vertical cross-sectional view of another embodiment of a closed and undeployed active glove box system. In the embodiment shown in  FIG. 7 , the locking plate comprises an extension paddle or tab  36  immediately adjacent the bladder wall  16 , configured to transmit expansion force from the bladder wall  16  to move the locking plate  30 . The tab may extend from a central portion of the locking plate and be positioned along an expansion path of the bladder wall. The tab may be used to quickly direct engagement of the locking plate with the latch system when the central portion of the locking plate, adjacent the latch rod, is spaced apart from the bladder wall. 
     In some embodiments, at least one attachment or weld point  26  of the bladder to the back panel  14  reaction surface is adjacent the locking plate. In some embodiments, the vertical distance between the locking plate and attachment point is 1-25% of the vertical span of the back panel. In some embodiments, the horizontal distance between the locking plate and attachment point is 1-25% of the width of the back panel. 
     In some embodiments, the placement of the inflator or the positioning, folding, and/or pleat shape of the bladder wall is designed to facilitate locking plate engagement with the latch system. In some embodiments, the vertical distance between the locking plate and inflator is 1-25% of the vertical span of the back panel. In some embodiments, the horizontal distance between the locking plate and inflator is 1-25% of the width of the back panel. 
       FIG. 8  shows an internal, front plan view of the back panel  14  of the door, showing the gear mechanism or coupler  24  with the latch rods  18   a  and  18   b . As shown in  FIGS. 4 and 10 , the sloped end of latch rod  18   a  extends from back panel  14  in order to engage the striker. Latch rod  18   a  has an angled nose which is engaged by the pushbutton plunger during door opening to release latch rod  18   a  from the striker pocket. Latch rod  18   b , also known as a pawl, is coupled to and mirrors the movement of pushbutton-adjacent latch rod  18   a  through the gear mechanism  24 . Pawl fins  31   a  and  31   b  are protrusions located along the length of the latch rods  18   a  and  18   b , adjacent the gear mechanism  24 . In a collision, the pawl fins, or other interlocking engagement features, are held by the locking plate to retain the latch rods in the latched configuration. 
       FIGS. 9 and 10  show an internal view of a door back panel  14  with a locking plate  30  mounted at the coupler  24 . The locking plate has lateral edges and a lateral width corresponding to the location of the pawl fins  31   a ,  31   b  of the latch rods  18   a ,  18   b  in the fully extended, closed configuration.  FIG. 9  shows a locking plate  30  embodiment having a shape that is substantially semi-cylindrical, curving vertically around, and placed slightly out from the movement path of the latch rods. The locking plate is mounted by standoff brackets  29  fastened by screws adjacent the coupler  24 . In some embodiments, the locking plate  30  is deformable. In some embodiments, the standoff brackets  29  are frangible or bendable. 
       FIG. 10  shows a locking plate embodiment having a shape similar to the embodiment of  FIG. 9  and having additional features of lateral edge flaring  33  and a central bulge  35 . In this embodiment, the central portion of the locking plate bulges toward the bolster bladder and away from the latch mechanism, helping to direct the forces and push the locking plate  30  between the pawl fins  31 . The lateral edges of the locking plate are flared  33 , or angled away from the latch rod mechanism  28 . The flaring  33  facilitates movement of the locking plate  30  towards the latch rods  18  and between the pawl fins  31  and inhibits subsequent movement away from the latch  28 . The locking plate  30  becomes wedged in place and remains lodged between the pawl fins  31 , thereby arresting movement and retraction of the latch rod  18 . In some embodiments, the locking plate arresting of latch rod movement is irreversible. 
       FIG. 11  is a top cross-sectional view of the active bolster glove box door showing back panel  14 , trim panel  15 , and bladder wall  16 . Bladder wall  16  attaches to back panel  14  via welding towers or other attachment points and panel  14  acts as a reaction surface during inflation. Bladder wall  16  is hermetically sealed around its outer periphery with trim panel  15  to create a cavity  23  for receiving inflation gas from the inflator. Outward ends of latch rods  18   a  and  18   b  are captured by strikers  20  and  21 , respectively. Inward ends of latch rods  18   a  and  18   b  are coupled to a gear mechanism  24  configured to provide a complementary reciprocating motion between latch rods  18   a  and  18   b.    
     Push button mechanism  12  includes gearing which converts movement of a push button into lateral movement. Thus, in response to extension of a plunger  25  within push button mechanism  12  against latch rod  18   a  when a user pushes in on the push button to open the door, the retraction of latch rod  18   a  is transmitted to latch rod  18   b  so that it also retracts. Gear mechanism  24  includes a spring that urges latch rods  18   a  and  18   b  towards their extended positions, and the extension of plunger  25  overcomes the spring force. During closing of the door, sliding contact between the sloped ends of latch rods  18   a  and  18   b  and the front walls of strikers  20  and  21  causes latch rods  18   a  and  18   b  to retract, thus overcoming the spring force until the door closes by a sufficient amount to allow the latch rods to enter the pockets behind the front striker walls. 
     A rear side of locking plate  30  is positioned immediately adjacent gear mechanism  24  and positioned such that a front surface of the locking plate  30  is adjacent the bladder  16 . The width and lateral edges of locking plate  30  are configured to engage pawl fins  31   a ,  31   b  upon receiving rearward force from an impact or bolster deployment. 
       FIG. 12  shows a simplified horizontal cross-sectional view of an alternate embodiment of the locking plate with pin-and-hole interlock elements. As in the previous examples, the locking plate  30  is positioned immediately adjacent the latch rods  18  and impelled into a locking position by bolster deployment or impact forces moving the hole  42  of the locking plate  30  into engagement at the pin  41 . 
       FIG. 13  shows a simplified horizontal cross-sectional view of an alternate embodiment of the locking plate with slot or notch and flange interlock elements. The locking plate  30  is positioned immediately adjacent the latch rods  18  and impelled into a locking position by bolster deployment or impact forces moving the flange  43  of the locking plate  30  into engagement at the notch  44 . 
       FIG. 14  shows a simplified horizontal cross-sectional view of an alternate embodiment of the locking plate with bracket leg and slot interlock elements. The locking plate  30  is positioned immediately adjacent the latch rods  18  and impelled into a locking position by bolster deployment or impact forces moving the bracket leg  45  of the locking plate  30  into engagement at the slot  46 . 
       FIG. 15  shows a simplified horizontal cross-sectional view of an alternate embodiment of the locking plate with hole and pin interlock elements for a glove box door without an active bolster. As in the previous examples, the locking plate  30  elements are positioned immediately adjacent the latch rods  18  and impelled into a locking position by impact forces moving the pin  41  of each locking plate  30  element into engagement at the hole  42 . In the absence of an active bolster, the locking plate  30  element bay be mounted to the inside surface of the front trim panel  15 . Location and spacing of the locking plate  30  elements may be selected to correspond with a predicted passenger knee impact location as well as with the latch elements. For example, a lateral spacing may be about 200 mm, or in the range of 150-250 mm. 
     Further embodiments of the latch lock may be used with a glove box door lacking an active bolster. In these embodiments, the locking plate is impelled into a locking position by impact forces, such as contact between the knees of a passenger and the trim panel of the glove box door. The mechanisms described are suitable for adapting the disclosed embodiments for use without an active bolster. 
     In an embodiment, a method is provided for retaining an automotive compartment door in a closed position following a collision, comprising: providing a lockplate and latch system with an active bolster; initiating deployment; inflating a bolster bladder; pushing a wall of the bladder against the locking plate to engage the latch; inhibiting latch movement and arresting the compartment door in a closed position. 
     In an embodiment, a method is provided for retaining an automotive compartment door in a closed position following a collision, the method comprising: providing a latchrod-engaging lockplate in a vehicle glove box latch system, having: an instrument panel housing defining a door space; a glove box door with a latch rod configured to move between an extended and retracted position; a striker on the housing for retaining a terminus of the latch rod in the extended position; and a locking plate configured to engage the latch rod in an impact, and initiating an impact force, thereby impelling the locking plate to arrest the latch rod. 
     In an embodiment, an automotive storage compartment is provided, comprising a panel frame with a striker disposed at a door opening; and a door including a back panel carrying a longitudinally-movable latch rod; wherein the latch rod and striker include sliding surfaces that retract the latch rod during door closing and interlock elements that engage to resist movement in response to a force against the door during a crash event in a direction to push the door through the door opening. 
     In some embodiments the distance between the latch and locking plate is less than 1 mm. In some embodiments the distance between the latch and locking plate is about 1-2 mm. In some embodiments the distance between the latch and locking plate is between about 0.5 and 5.0 mm. In some embodiments the distance between the latch and locking plate is less than 10 mm. 
     In certain embodiments, the rearward force, from an impact or bolster deployment, may move the locking plate as a unitary structure. In other embodiments it may deform the locking plate into the gap between the pawl fins. In some embodiments, the locking plate is comprised of a plurality of structures. In some embodiments, the force may cause a supporting structure, such as a mounting boss or standoff bracket, to break, bend, or deform, such that the locking plate moves into a locking position. In additional embodiments, the force may cause a portion of the locking plate, such as a protruding pin or catchment, to break off in a mating hole or catch on one or more latch rods. In further embodiments the locking plate may be formed into a sheath or multipart structure to sandwich or capture one or more latch rods and arrest movement. 
     In particular non-limiting examples of installations and embodiments, the locking plate or lock pins may be formed of steel, aluminum, metal alloys, nylon, resin, plastic, composites, or other materials with suitable properties as to stiffness, deformation, and fracture-resistance. The structure may be adapted by means known in the art, such as with the use of brackets, mounting guides, ridges, grooves, directional slots, structural ribbing, crumple regions, vibration cushioning, non-slip coatings, or other elements, without deviating from the scope of the disclosure. The attachment of the interlock may include screws, rivets, pins, clips, clamps, welds, molding, adhesives, and the like. 
     The structures and features of the locking structure and system may be adapted for use with various glove box door actuation styles, including lift paddle, side pull, and push button options. Likewise, the structures and features of the locking structure and system may be adapted for use with various glove box latch systems which may include latch rod and pawl, single latch rod, dual latch rod, and other latch systems. 
     It is to be understood that positional references, such as right, left, top, bottom, upper, and lower, are made for ease of explanation and to describe relative position only. Such terms do not specify positional relationships to the vehicle or environment unless explicitly stated. 
     The terms and expressions which have been employed are used as terms of description and not of limitation. Whenever a range is given in the specification, all intermediate ranges and subranges, as well as all individual values included in the ranges given are intended to be included in the disclosure. It should be understood that, although the present invention has been specifically disclosed by particular embodiments and examples, optional features, modification and variation of the concepts herein disclosed may be used by those skilled in the art, and such modifications and variations are considered to be within the scope of the invention as defined by the appended claims.
A glove box latch system for an automotive vehicle is provided. A glove box door is mounted in an instrument panel housing. The glove box door comprises a movable latch rod and an adjacent lock plate. In the event that the vehicle is involved in a collision, the lock plate engages the latch rod. The engaged lock plate arrests movement of the latch rod, securing the latch rod in the closed position and preventing the glove box door from opening. Exemplary methods and structures for restraining movement of latch rods are provided.