Abstract:
A heavy duty vehicle door latch assembly is provided with interconnected latch, release, and bell crank modules to form a single, pre-assembled unit for quick and easy installation on the inside of a vehicle door. The modular design allows for application to multiple door layouts and arrangements. The release module includes a locking mechanism using a lever rod to disallow latch component movement. A release lever interfaces with the lock lever to automatically unlock and release the latch in a single motion. A lockout feature is also provided to prevent accidental locking of the door.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a vehicle door latch assembly, and particularly to an assembly adapted for use on heavy duty doors, such as military armored vehicles. The assembly functions for closing, latching, locking, unlocking, unlatching, and opening an occupant door of a heavy duty off-road and/or armored military vehicle. 
     BACKGROUND OF THE INVENTION 
     Conventional consumer automobiles and trucks have doors which typically weigh 50-60 pounds. Heavy duty vehicles, such as armored military vehicles, have doors which weigh 500-600 pounds. Standard door locks and latches for automobiles, heavy truck and other specialty vehicles will not stand up to the rigors required of such heavy duty vehicles, such as repeated cycles, vibration, dust and dirt, extreme temperatures, arms fire and bomb blasts. 
     Manufacturers of heavy duty vehicles, including armored military vehicles and other off-road vehicles, currently purchase separate components for the closing, latching, and locking of a vehicle door. Such components typically include an inside door release, a latch assembly, a locking logic assembly, interlocking control rods, a bell crank interface for exterior door handle actuation, an occupant pull handle for inside the door, and covers or housings for the individual components. All of these pieces are mounted separately to the door and then interconnected to one another. Significant positioning adjustment is often necessary for proper function of the assembled components. Such individual installation of the various components is time consuming and costly, and thus undesirable from a manufacturing perspective. 
     Therefore, a primary objective of the present invention is the provision of an improved heavy duty vehicle door latch assembly. 
     Another objective of the present invention is the provision of a heavy duty door latch assembly which is preassembled as a singular modular unit for subsequent assembly on to the door of the vehicle. 
     Another objective of the present invention is the provision of a heavy duty door latch assembly having multiple modules interconnected to form a single, rigid unit which can be quickly and easily installed on a door of a heavy duty vehicle. 
     Still another objective of the present invention is the provision of a heavy duty door latch assembly which is mounted on the inside of a vehicle door using a total of only 4-6 fasteners. 
     Still another objective of the present invention is the provision of a heavy duty vehicle door latch assembly which prohibits accidental vehicle lockout. 
     Another objective of the present invention is the provision of a heavy duty vehicle door latch assembly which can be quickly opened from inside the vehicle with a single actuation step, whether the door is locked or unlocked. 
     A further objective of the present invention is the provision of a heavy duty vehicle door latch assembly having a release lever which overrides a lock lever from inside the vehicle. 
     Yet another objective of the present invention is the provision of a heavy duty vehicle door latch assembly having a bell crank module to allow opening of the vehicle door from outside the vehicle. 
     Still another objective of the present invention is the provision of a heavy duty vehicle door latch assembly having a latch module, a release module, and a bell crank module, all of which are assembled into an integral unit for installation on the vehicle door. 
     A further objective of the present invention is the provision of a heavy duty vehicle door latch assembly having a modular design to allow for application to multiple door layouts and arrangements. 
     Another objective of the present invention is the provision of a heavy duty vehicle door latch assembly which replaces conventional, complex latch-logic locking mechanisms with a simple locking rod mechanism to disallow movement of the latch rotor. 
     Still another objective of the present invention is the provision of a heavy duty vehicle door latch assembly having latch and release modules with interconnecting actuation rods extending through a tube which forms a door handle for a person inside the vehicle. 
     Another objective of the present invention is to provide a single latch and release unit which can be surface mounted on the inside of a flat door. 
     Yet another objective of the present invention is the provision of an improved heavy duty vehicle door latch assembly for use on armored military vehicles which is durable in use. 
     BRIEF SUMMARY OF THE INVENTION 
     A modular assembly is provided for latching, locking, and opening a vehicle door mounted in a door frame for movement between open and closed positions. The assembly includes a latch module, a release module, and a bell crank module, all of which are interconnected to form a single, pre-assembled unit for mounting to the door. 
     The latch module includes a rotor and a catch adapted to engage and disengage a striker bolt on the door frame. The release module includes a release lever and a lock lever. A release rod extends between the release lever and the latch module. A lock rod extends between the lock lever and the latch module. The bell crank module includes a bell crank lever and a bell crank rod extending between the bell crank lever and the latch module. 
     The lock lever is moveable between locked and unlocked positions. In the unlocked position, the rotor of the latch module is free to rotate between open and closed positions. The rotor is spring biased to the open position, and the catch holds the rotor in the closed position. When the lock lever is moved to the locked position, a locking pin engages the catch, and thereby prevents the rotor from moving from the open position to the closed position. 
     The release lever is moveable between a neutral position and an actuated position. When the release lever is in the neutral position, the door can be closed, latched, and locked. When the door is closed and the rotor is latched or locked, and the release lever is actuated, the release rod moves a first arm in the latch module to pivot the catch, and thereby open the rotor, so that the door is unlatched. Actuation of the release lever also automatically moves the lock lever to the unlocked position, such that the rotor is free to move to the open position, without a separate step of moving the lock lever to the unlocked position. Thus, the release lever allows the door to be opened by a person inside the vehicle in a single step, whether the latch module is locked or unlocked. 
     The bell crank lever moves between a neutral closed position and an actuated open position. Actuation of the bell crank lever is accomplished through the exterior push button door handle of the vehicle. When the door is closed and the lock lever is in the locked position such that the latch rotor is locked, the bell crank lever cannot be actuated from outside the vehicle. When the door is closed and the lock lever is in the unlocked position, the bell crank lever can be actuated by the outside handle of the vehicle to move the rotor from the closed position to the open position, thereby unlatching the latch module for opening the door from outside the vehicle. 
     The assembly has an anti-lockout feature. When the door is open and the rotor is in the open position, movement of the lock lever to the locked position precludes movement of the rotor to the closed position, such that the door cannot be accidentally locked. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a first embodiment of the assembly of the present invention, including a latch module, a release module, and a remote bell crank module. 
         FIG. 2  is a front elevation view of the inside door assembly shown in  FIG. 1 . 
         FIG. 3  is an end elevation view of the latch and release modules of the assembly shown in  FIG. 1 , with the cover removed for clarity. 
         FIG. 4  is a bottom plan view of the release module of the assembly shown in  FIG. 1 . 
         FIG. 5  is a top plan view of the latch module of the assembly shown in  FIG. 1 , with the cover removed for clarity. 
         FIG. 6  is a perspective view of the latch module of the assembly shown in  FIG. 1  with the cover removed for clarity. 
         FIG. 7  is a perspective view of the release module of the assembly shown in  FIG. 1 , with the cover removed for clarity. 
         FIG. 8  is a perspective view of a second embodiment of the assembly of the present invention, including a latch module and a release module with an integrated bell crank module. 
         FIG. 9  is a front elevation view of the inside door assembly shown in  FIG. 8 . 
         FIG. 10  is an end elevation view of the assembly of  FIG. 8 . 
         FIG. 11  is a perspective view of the latch module of the assembly shown in  FIG. 8 , with the cover exploded for clarity. 
         FIG. 12  is a view similar to  FIG. 9 , with cover portions and tube removed for clarity. 
         FIG. 13  is a partially exploded view of the latch module with the integrated bell crank module. 
         FIG. 14  is another view of the latch module of the assembly shown in  FIG. 8 , with the cover exploded. 
         FIG. 15  is a side elevation view of the assembled latch mechanism and arms 
         FIG. 16  is a partially exploded perspective view of the latch mechanism and arms of the latch module according to the present invention. 
         FIG. 17  is a plan view of the assembled latch mechanism and arms. 
         FIG. 18  is an end view of the assembled latch mechanism and arms. 
         FIG. 19  is a partial sectional view showing the lock pin in a locked position. 
         FIG. 20  is a partial sectional view showing the lock pin in an unlocked position. 
         FIG. 21  is a sectional view of the integral bell crank module of the second embodiment and the exterior push button door handle in a deactivated state. 
         FIG. 22  is a skeletal view of the actuation rods and levers for the first embodiment. 
         FIG. 23  is a skeletal view of the actuation rods and levers for the second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the drawings a heavy weight door, such as an armored door of a military vehicle is generally designated by the reference numeral  11 . The door  11  is mounted to a door frame  13  by hinges for movement between open and closed positions. The door  11  and frame  13  are shown in  FIGS. 2 and 9 . The door includes a conventional exterior handle  15  with a push button  17  and a plunger  19 , as seen in  FIG. 21 . 
     A first embodiment of the heavy duty vehicle door latch assembly of the present invention is generally shown in  FIGS. 1-7  and designated by the reference numeral  10 A. A second embodiment of the assembly is shown in  FIGS. 8-14  and is designated by the reference numeral  10 B. Both embodiments include a latch module  12 , a release module  14 , and a bell crank module  16 . In the first embodiment of the assembly  10 A, the bell crank module  16  is remote from the latch module  12 . In the second embodiment of the assembly  10 B, the bell crank module  16  is integral or incorporated with the latch module  12 , rather than being remote therefrom. Otherwise, the latch and release modules  12 ,  14  are substantially identical in both assembly embodiments  10 A and  10 B. 
     The latch module  12 , release module  14 , and bell crank module  16  are interconnected so as to form a single, rigid, modular unit which is pre-assembled before mounting the unit to the inside of the door  11 . 
     The latch module  12  includes a housing  18  which pivotally supports a catch  20  and a rotor  22 . The rotor  22  is pivotal between open and closed positions, but is biased to the open position by a spring  24 . The rotor  22  is adapted to engage and disengage a striker bolt (not shown) on the door frame  13 , such that the door  11  is moveable between a latched close position and an unlatched open position. The latch module  12  also includes a mounting bracket  26  having two holes  28  for mounting the latch module  12  to the inside of the door  11  using a pair of bolts (not shown). The bracket  26  is U-shaped so as to define walls  26 A,  26 B and  26 C, as seen in  FIG. 6 . The latch housing  18  is bolted or otherwise secured to the central wall  26 B. The holes  28  are in the exterior wall  26 A. 
     The latch module  12  also includes first and second arms  30 ,  32  which are pivotally mounted to the housing  18  by a pin  33 . The latch arms  30 ,  32  are best seen in  FIGS. 15-18 . The arms  30 ,  32  function to trip the catch  20  so that the rotor  22  will pivot from the closed position to the open position under the bias of the spring  24 , as described in further detail below. 
     The latch module  12  further includes a locking pin  34  moveable between extended and retracted positions. In the extended position, the locking pin  34  locks the catch  20  against movement, so that the rotor  22  cannot be released from the closed position, or move from the open position to the closed position. In the retracted position, the locking pin  34  is disengaged from the catch  20 , which is therefore free to pivot to allow the rotor  22  to move between the closed position and the open position. 
     Movement of the locking pin  34  between the extended and retracted positions is controlled by an arm  36 . The arm  36  has a first end  38  and a second end  40 . The first end  38  of the arm  36  is pivotally connected to the exterior wall  26 A of the bracket  26 , with the second end  40  being free to move back and forth, as described below. The locking pin  34  is attached to the arm  36  between the first and second ends  38 ,  40  in any convenient manner. For example, as seen in  FIG. 6 , the inner end of the locking pin  34  includes a device  42  which mounts to the arm  36  via a bolt or pin  44 . Thus, when the second end  40  of the arm  36  is pulled, the arm  36  pivots about the first end  38  so as to pull the locking pin  34  to a retracted position. When the second end  40  of the arm  36  is pushed, as described below, the arm  36  pivots about the first end  38  so as to push the locking pin  34  into the extended position engaging the catch  20  to prevent opening of the rotor  22 . 
     A cover plate  46  can be mounted to the bracket  26  of the latch module  12  so as to enclose the module, as best seen in  FIG. 1 . 
     The release module  14  includes a mounting bracket  48  with a pair of holes  50  for mounting the release module  14  to the interior of the door  11  using a pair of bolts. The latch  18  mounted to the bracket  48  with four bolts. A housing  49  is secured to the bracket  48  to enclose the release module  14 . The release module  14  further includes a release lever  52  and a lock lever  54 . The release lever  52  includes a U-shaped body  56  and a hand grip portion  58  extending from the body  56 . The release lever  52  is pivotally mounted to the bracket  48  by an elongated pin  60  so that the release lever  52  is moveable between a normal or neutral position and an actuated position. The release lever  52  is biased to the neutral position by a spring  62 , best shown in  FIG. 7 . 
     The lock lever  54  is pivotally mounted to the bracket  48  by the pin  60  so as to be moveable between locked and unlocked positions. A detent  64  engages spaced apart depressions  66  in the lock lever  54  so as to retain the lock lever in the selected locked or unlocked position. The lock lever  54  has a U-shaped body  68  with a finger tab portion  70  extending from the body  68 . If the lock lever  54  is in the locked position, when the release lever  52  moves from the neutral position to the actuated position, a portion of the release lever body  56  engages a portion of the lock lever body  68  to automatically move the lock lever  54  from the locked position to the unlocked position. The release lever  52  and the lock lever  54  are both mounted on a pin  60 , which defines the pivot axis for both levers  52 ,  54 . 
     A release rod  72  extends between the release lever  52  and one end of the first latch arm  30 . A lock rod  74  extends between the lock lever  54  and an end of the latch arm  32 . The ends of the rods  72 ,  74  are secured to the connecting structures by pins, rivets, bolts, or other convenient fasteners. The rods  72 ,  74  extend through a tube  76  having opposite ends welded or otherwise attached to the latch bracket  26  and the release bracket  48 . The tube  76  protects the rods  72 ,  74  from being bent, and also provides a hand grip for a passenger in the vehicle to open and close the door  11 . 
     It is understood that the length of the rods  72 ,  74  and  86  and the tube  76  can be varied so as to accommodate different vehicle doors. Also, the relative position of the latch module  12  relative to the release module  14  can be varied to accommodate different vehicle doors. For example, in  FIG. 2 , the latch module  12  and release module  14  are oriented substantially on the same horizontal plane, whereas in  FIG. 9 , the latch module  12  is positioned above the release module  14 . 
     An upwardly extending hand grip  94  is welded to the bracket  48 , and includes a slot  96  for receiving a portion of the release lever  52  when the lever  52  is actuated. The grip  94  facilitates squeezing actuation of the release lever  52  by a person in the vehicle. 
     The bell crank module  16  includes a bell crank lever  78 . In the first embodiment  10 A of  FIGS. 1-7 , the bell crank lever  78  is pivotally mounted in a U-shaped bracket  80  having a pair of holes  82  for mounting the bell crank module  16  to the inside of the door  11 . A bolt or pin  84  defines the pivot axis for the bell crank lever  78 . In the second embodiment  10 B shown in  FIGS. 8-14 , the bell crank lever  78  is mounted in the latch bracket  26  by the bolt or pin  84  so as to be integral with the latch module  12 . 
     The bell crank module  16  also includes a connecting rod  86  having one end connected to the bell crank lever  78  and the opposite end connected to one end of the second latch arm  32 . The length of the rod  86  is longer for the remote bell crank module of the first embodiment  10 A, and shorter for the bell crank module of the second embodiment  10 B. The rod  56  extends through a tube  92 . 
     The bell crank module  16  is aligned with the outer door handle  15  of the door  11 , such that actuation of the outside handle push button  17  or operating paddle pushes the plunger  19  into engagement with the bell crank lever  78  so as to pivot the bell crank lever  78  from a first neutral position to a second operative position. See  FIG. 21 . A hole is provided in the bell crank bracket  80  or in the latch bracket wall  26 A to allow a reciprocating arm on the outer door handle to move the bell crank lever  78 . The bell crank lever  78  is normally biased to the first position by a spring  88  on the pin  84 . A housing  90  is secured to the bracket  80  so as to enclose the bell crank lever  78  and connecting rod  86 . 
     In operation, the latch assemblies  10 A,  10 B function to latch, lock, unlock, unlatch, and open the door  11 . When the door  11  is open, the rotor  22  is in an open position, and when the door is closed, the rotor  22  is normally in a closed position. If the lock lever  54  is in the unlocked position, the door  11  can be closed, wherein the rotor  22  will engage the striker bolt (not shown) on the door frame  13  and pivot to the closed or latched position and be retained by the catch  20  against the normal bias of a spring (not shown) which urges the rotor  22  to the open position. If the lock lever  54  is moved to the locked position while the door  11  is open, the lock rod  74  pushes the locking pin  34  to the extended position, which locks the catch  20  against rotation, which precludes rotation of the rotor  22  to the locked position. Accordingly, this safety feature prevents a person from being accidentally locked out of the vehicle by actuating the lock lever  54  while the door  11  is open. The lock lever  54  can be moved to the locked position to lock the rotor  22  only after the door  11  has been closed. 
     With the door  11  closed and latched, and with the lock lever  54  in the unlocked position, the door  11  can be opened from the inside by the release lever  52  or from the outside by actuation of the outside door handle. From the inside, actuation of the release handle or lever  52  pulls the release rod  72 , which in turn pivots the first latch arm  30  about the pivot axis  33 , thereby rotating the catch  20  out of engagement with the rotor  22 , such that the rotor  22  is released for rotation by the biasing spring to the open position and disengagement from the striker bolt, so that the door  11  can be opened. A person can also open the door  11  from the outside when the rotor  22  is latched but not locked, by actuating the outside door handle which pivots the bell crank lever  78  about the axis  84  which pushes the connecting rod  86  so as to rotate the second latch arm  32  about the pivot axis  33 , thereby rotating the catch  20  out of engagement with the rotor  22 , such that the rotor  22  is released and pivots to the open position for disengagement from the striker bolt. 
     When the door  11  is closed, the rotor  22  is in the closed position. Movement of the lock lever  54  to the locked position pushes the lock rod  74  so as to extend the lock pin  34 , which precludes rotation of the catch  20 , such that the rotor  22  is locked against rotation from the closed position to the open position. When the rotor  22  is locked, the bell crank lever  78  is inoperative because arm  32  and the catch  20  cannot pivot. Thus, in the locked condition, a person cannot open the door from the outside using the outside door handle. 
     When the door  11  is locked, a person on the inside of the vehicle can open the door simply by actuating the release lever  52 , and without the need to separately move the lock lever  54  from the locked position to the unlocked position. More particularly, with the door  11  locked, the release lever  52  can be squeezed or depressed so as to move from its normal or neutral position to its actuated position. Such movement rotates the U-shaped body  56  about the axis  60  so as to engage the body  68  of the lock lever  54 , and thereby automatically pivot the lock lever  54  about axis  60  from the locked position to an unlocked position. Simultaneously, rotation of the release body  56  pulls the release rod  72  so as to pivot the first latch arm  30 , which in turn pivots the catch  20  out of engagement with the rotor  22 , such that the rotor  22  is biased to the open position to disengage the striker bolt, and thereby allow the door  11  to open. 
     The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. From the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives.