Abstract:
The present invention is directed to improvements in latch design. The illustrated embodiment of the present invention is a rotary pawl latch with the capability to provide a compressive force between the first member and the second member. The illustrated embodiment of the present invention is of an electromechanical type. The control circuit of the latch detects when a striker attached to one member, for example a door, has moved the pawl to a first latched position. A motor is then activated that drives the pawl to a second latched position to provide compression between the first member and a second member, for example a door frame.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a latch for releasably securing a first member, such as a door, panel or the like, relative to a second member. 
         [0003]    2. Description of the Prior Art 
         [0004]    Latches are used to releasably secure panels, covers, doors, electronic modules, and the like to other structures such as compartments, cabinets, containers, doorframes, other panels, frames, racks, etc. Although many latch designs are known in the art, none offers the advantages of the present invention. The advantages of the present invention will be apparent from the attached detailed description and drawings. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to improvements in latch design. The illustrated embodiment of the present invention is a rotary pawl latch with the capability to provide a compressive force between the first member and the second member. The illustrated embodiment of the present invention is of an electromechanical type. The control circuit of the latch detects when a striker attached to one member, for example a door, has moved the pawl to a first latched position. A motor is then activated that drives the pawl to a second latched position to provide compression between the first member and a second member, for example a door frame. 
         [0006]    It is an object of the present invention to provide an electromechanical latch that provides compression between two members. 
         [0007]    It is another object of the present invention to provide an electromechanical latch that can reverse operation to open. 
         [0008]    It is yet another object of the present invention to provide an electromechanical latch that can detect obstructions and reverse operation. 
         [0009]    It is yet another object of the present invention to provide an electromechanical latch that can detect premature movement of the pawl to a fully latched position and reverse operation. 
         [0010]    It is yet another object of the present invention to provide an electromechanical latch that continues to provide a latching function in the event of power failure. 
         [0011]    It is yet another object of the present invention to provide an electromechanical latch that permits manual opening in the event of power failure. 
         [0012]    These and other objects of the invention will become apparent from the attached description, drawings, and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIGS. 1-10  are views of a latch assembly according to the present invention. 
           [0014]      FIGS. 11A-12  are exploded views of a latch according to the present invention. 
           [0015]      FIGS. 13-15  are views of a latch according to the present invention showing the latch in the unlatched configuration with the cover removed to reveal internal detail. 
           [0016]      FIG. 16  is a view of a latch according to the present invention showing the latch in the unlatched configuration. 
           [0017]      FIGS. 17-21  are a sequence of views of a latch according to the present invention showing the pawl moving from the unlatched position to the first latched position with the cover removed to reveal internal detail. 
           [0018]      FIG. 22  is a view of a latch according to the present invention showing the pawl in the first latched position. 
           [0019]      FIGS. 23-25  are fragmentary views of a latch according to the present invention showing the pawl in the first latched position with the cover removed to reveal internal detail. 
           [0020]      FIGS. 26-35  are a sequence of views of a latch according to the present invention showing the pawl moving from the first latched position to the second latched position and the cam gear returning to its starting position with the cover removed to reveal internal detail. 
           [0021]      FIGS. 36-49  are a sequence of views of a latch according to the present invention showing the pawl moving from the second latched position to the unlatched position and the cam gear returning to its starting position with the cover removed to reveal internal detail. 
           [0022]      FIGS. 50-51  are views of the second portion of the housing of a latch according to the present invention. 
           [0023]      FIGS. 52-53  are views of the cam gear axle of a latch according to the present invention. 
           [0024]      FIGS. 54-60  are views of the cam gear of a latch according to the present invention. 
           [0025]      FIGS. 61-65  are views of the trigger spring of a latch according to the present invention. 
           [0026]      FIGS. 66-68  are views of the trigger of a latch according to the present invention. 
           [0027]      FIGS. 69-73  are views of the combination gear of a latch according to the present invention. 
           [0028]      FIG. 74  is a view of the motor of a latch according to the present invention. 
           [0029]      FIGS. 75-76  are views of the bushing for supporting the end of the motor shaft of a latch according to the present invention. 
           [0030]      FIG. 77  is a view of the motor cover of a latch according to the present invention. 
           [0031]      FIGS. 78-79  are views of the pawl axle of a latch according to the present invention. 
           [0032]      FIGS. 80-83  are views of the pawl torsion spring of a latch according to the present invention. 
           [0033]      FIGS. 84-86  are views of the pawl of a latch according to the present invention. 
           [0034]      FIGS. 87-88  are views of the circuit board of a latch according to the present invention. 
           [0035]      FIGS. 89-92  are views of the support plate of a latch according to the present invention. 
           [0036]      FIGS. 93-94  are views of the torsion spring of the trigger actuator lever of a latch according to the present invention. 
           [0037]      FIGS. 95-97  are views of the trigger actuator lever of a latch according to the present invention. 
           [0038]      FIGS. 98-99  are views of the torsion spring of the striker detector of a latch according to the present invention. 
           [0039]      FIGS. 100-104  are views of the striker detector of a latch according to the present invention. 
           [0040]      FIGS. 105-106  are views of the first portion of the housing of a latch according to the present invention. 
           [0041]      FIGS. 107-108  are views of the trigger axle of a latch according to the present invention. 
           [0042]      FIGS. 109-110  are views of the combination gear axle of a latch according to the present invention. 
           [0043]      FIGS. 111-112  are views of the worm gear of a latch according to the present invention. 
           [0044]    The same reference numbers are used consistently throughout the several views. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0045]    Referring to  FIGS. 1-112 , a latch  200  in accordance with an exemplary embodiment of the present invention can be seen. The latch  200  includes a latch housing  202 , a pawl  204 , a trigger or catch  206 , and actuation means for selectively moving the trigger  206  out of engagement with the pawl  204  and for moving the pawl  204  from a first or initial latched position to a second or final latched position to thereby draw a portion of a striker farther into the interior of the housing  202 . In the illustrated embodiment, an electrically operated actuator assembly  208  serves as the actuation means. 
         [0046]    The latch  200  is generally applicable wherever one or more closure members need to be secured in a certain position. The latch  200  can be used together with the striker  308  to secure any two closure members together. In the illustrated example, the latch  200  is shown being used for securing a panel  300  relative to some compartment (not shown) for which the panel  300  serves as a closure. In use, the latch  200  can be secured to the interior of the compartment, for example the passenger compartment of an automobile, using any well known means such as, for example, screws, bolts, or the like, with the latch  200  positioned such that it can be engaged by the striker  308 . 
         [0047]    Preferably, the housing  202  is of the two-piece type having a first portion  211  and a second portion  213  so as to allow the housing  202  to receive the various components of the latch  200 . Furthermore, the housing must be adapted to allow an unobstructed path to the pawl slot  258  for the striker  308  when the pawl  204  is in the open or unlatched position relative to the housing  202 . The housing  202  has an opening that allows at least a portion of the striker  308  to enter the housing  202  for engagement by the pawl  204 . In the illustrated example, the opening is in the form of a slot  212  that passes through the first and second portions  211 ,  213  of the housing  202 . The slot  212  forms an open, approximately U-shaped cut-out in the housing  202  as viewed in profile. The slot  212  allows at least a portion of the striker  308  to enter the housing  202  for engagement by the pawl  204 . The slot  212  allows an unobstructed path to the pawl slot  258  when the pawl  204  is in the open configuration relative to the housing  202 . The slot  212  is sized such that the housing  202  will not interfere with the movement of the striker  308  relative to the housing  202  as the pawl  204  is moved from the unlatched position to the first latched position relative to the housing  202  by contact with the striker  308  and as the pawl  204  is rotated to the second latched position relative to the housing  202  by the electrically operated actuator assembly  208 . In the illustrated example, the housing is provided with a motor cover  228 , which provides a protective cover for the motor. 
         [0048]    The electrically operated actuator assembly  208  includes a motor  210 , a worm gear  214  that is in the form of an Archimedes or helical screw, a combination gear  216 , a cam gear  218 , the support plate  215 , and the printed circuit board  230 . The motor  210  has an output shaft  220  that normally rotates in response to the motor being energized. Reversing the polarity of the current supplied to the motor  210  causes the direction of rotation of the output shaft  220  to be reversed. The motor  210  is received in the housing  202  and is installed at a fixed location therein. The worm gear  214  is attached to the output shaft  220  of the motor  210  such that the worm gear  214  rotates with the shaft  220  as a unit during normal operation of the latch  200 . 
         [0049]    The combination gear  216  includes two adjacent coaxial gear wheels  229 ,  227  that rotate as a unit about a common axis of rotation. The first gear wheel  229  is of a larger diameter as compared to the second gear wheel  227 . The combination gear  216 , including the gear wheels  229 ,  227 , may be of one-piece or two-piece construction. The combination gear  216  is rotationally supported in the housing  202  by the combination gear axle  223 . The worm gear  214  is in mesh with the combination gear  216 . In the illustrated example, the helical screw of the worm gear  214  engages the gear teeth  225  of the gear wheel  229 , such that the worm gear  214  is in mesh with a first set of teeth  225  of the combination gear  216 . Accordingly, rotation of the worm gear  214  causes rotation of the combination gear  216  when the motor  210  is energized. 
         [0050]    The cam gear  218  includes a gear wheel  222 , a first cam  203 , and a second cam  205 . The first cam  203  is provided on one side of the gear wheel  222  and the second cam  205  is provided on the opposite side of the gear wheel  222 . The gear wheel  222 , the first cam  203 , and the second cam  205  rotate as a unit about a common axis of rotation. The gear wheel  222  of the cam gear  218  has a plurality of gear teeth  310  evenly distributed about its circumference. The first cam  203  has a cam lobe  207 , located at a distance from the axis of rotation of the cam gear  218 , for rotating the pawl  204 . The second cam  205  is in the form of an elongated, arc-shaped raised rib and functions to selectively trip or move the catch or trigger  206 . In the illustrated example, the cam gear  218 , including the gear wheel  222 , the first cam  203 , and the second cam  205 , is of one-piece construction. The cam gear  218  is rotationally supported in the housing  202  by the cam gear axle  209 . The cam gear  218  is in mesh with the combination gear  216 . In the illustrated example, the teeth  310  of gear wheel  222  of the cam gear  218  engage the gear teeth  312  of the gear wheel  227 , such that the cam gear  218  is in mesh with a second portion or second set of teeth of the combination gear  216 . Accordingly, rotation of the combination gear  216  causes rotation of the cam gear  218  when the motor  210  is energized. 
         [0051]    The support plate  215  is supported by the housing  202  in a fixed position relative to the housing  202 . The pawl  204  is supported for rotational movement relative to the support plate  215  and the housing  202  by the pawl axle  238 . The trigger  206  is supported for rotational movement relative to the support plate  215  and the housing  202  by the trigger axle  270 . The support plate  215  has a cut-out  224  proximate the pawl  204  such that the support plate  215  will not interfere with the movement of the striker  308  relative to the housing  202  as the pawl  204  is moved from the unlatched position to the first latched position relative to the housing  202  by contact with the striker  308  and as the pawl  204  is rotated to the second latched position relative to the housing  202  by the electrically operated actuator assembly  208 . The support plate  215  has a first window in the form of an arcuate, elongated slot  221  that allows the position of the pawl to be detected by sensors  332  and  316  provided on the circuit board  230 . The printed circuit board  230  is positioned on the opposite side of the support plate  215  as compared to the pawl  204 , the trigger  206  and the cam gear  218 . The circuit board  230  is supported by the housing  202  in a fixed position relative to the housing  202  and the support plate  215 . 
         [0052]    The support plate  215  has a second window  324  to allow detection of the position of the cam gear  218  by a sensor  326  provided on the circuit board  230 . The second window  324  is square shaped. A portion of the cam lobe  207  of the first cam  203  registers with the second window  324 , at least when the cam gear  218  is in its initial or starting position, to allow the sensor  326  to detect when the cam gear  218  is in its initial or starting position. The sensor  326  then generates a signal to the latch control circuit  235  when the cam gear  218  is in its initial or starting position to thus allow the latch control circuit  235  to detect whether or not the cam gear  218  is in its initial or starting position. 
         [0053]    As previously stated the latch assembly  200  includes a pawl  204  shown pivotally or rotationally supported on the support plate  215  with suitable attachment means such as the pawl axle  238  that passes through the hole  240  in the pawl  204 . The support plate  215  is provided with a hole  232  for receiving part of the pawl axle  238 . Thus, the pawl  204  is rotationally supported relative to the support plate  215 . 
         [0054]    The pawl  204  has first and second notches  254 ,  233  provided for engagement by the trigger  206 . The pawl  204  is provided with a pawl slot  258  to capture and hold the striker  308  when the pawl  204  is in either one of the first latched position (shown in  FIGS. 19-26 ) and the second latched position (shown in  FIGS. 29-37 ) relative to the support plate  215 . In the illustrated example, the striker  308  has a rod-shaped portion  234  that engages the pawl slot  258  as the panel  300 , for example a car door, is moved to the closed position relative to the vehicle&#39;s passenger compartment (not shown) and consequently relative to the latch  200 . 
         [0055]    During normal operation, assuming the latch  200  is initially in the normal unlatched configuration shown in  FIGS. 13-16 , when the panel  300  is closed, the rod-shaped portion  234  of the striker  308  will be positioned or caught in the pawl slot  258  with the pawl  204  being moved to the first latched position relative to the support plate  215  and housing  202 . 
         [0056]    A pawl torsion spring  262  is installed on the support plate  215  with the coiled portion  264  of the torsion spring  262  surrounding the pawl axle  238 . An arm  268  of the torsion spring  262  engages the pawl  204 . The torsion spring  262  also has a second arm  272  that engages the support plate  215  or the housing  202 . 
         [0057]    With the arm  272  of the torsion spring  262  in engagement with the support plate  215  or the housing  202 , the arm  268  of the torsion spring  262  exerts a force on the pawl  204  that biases the pawl  204  toward the open or unlatched position relative to the support plate  215 . 
         [0058]    The trigger  206  is pivotally supported on the support plate  215 . The pivot axis of the trigger  206 , as defined by the trigger axle  270 , is parallel to the pivot axis or axis of rotation of the pawl  204 . Furthermore, the pivot axis of the trigger  206 , as defined by the trigger axle  270 , is spaced apart from the pivot axis or axis of rotation of the pawl  204 . The trigger  206  is pivotally movable between any one of a first engaged position (shown in  FIGS. 19-26 ) and a second engaged position (shown in  FIGS. 29-37 ) and a disengaged position (shown in  FIGS. 17 ,  18 , and  39 ) and is spring biased toward the first and second engaged positions. In the illustrated embodiment, the first and second engaged positions of the trigger  206  may be coincident, but they need not be so. A trigger spring  288  is provided for biasing the trigger  206  toward the first and second engaged positions. In other words, the trigger spring  288  biases the trigger  206  toward engagement with the pawl  204 . The trigger spring  288  is a torsion spring and has a coiled portion  274 , a first arm  276 , and a second arm  278 . The trigger spring  288  is installed on the support plate  215  with the coiled portion  274  of the torsion spring  288  surrounding the trigger axle  270 . The arm  276  of the torsion spring  288  engages the trigger  206 . The second arm  278  of the torsion spring  288  engages the support plate  215  or the housing  202 . 
         [0059]    The trigger  206  has a lever arm  284  that extends on one side of the pivot axis of the trigger  206  as defined by the trigger axle  270 . The trigger axle  270  passes through a hole in the trigger  206 . The trigger  206  has a tooth  290  that engages the first notch  254  of the pawl  204  to hold or retain the pawl  204  in the first latched position relative to the support plate  215 . Also, the tooth  290  of the trigger  206  engages the second slot  233  of the pawl  204  to hold or retain the pawl  204  in the second latched position relative to the support plate  215 . 
         [0060]    The trigger  206  has associated with it a trigger actuator lever  286 . The trigger actuator lever  286  is mounted within the housing  202  so that it can rotate about a common axis with the trigger  206 . The trigger actuator lever  286  has a one-way rotation stop  236 . The trigger actuator lever  286  is provided with a torsion spring  242  that biases the one-way rotation stop  236  into engagement with the trigger  206 . When the cam gear  218  starts from its initial starting position (see  FIGS. 13-15 ) and rotates in the first or forward direction until the second cam  205  engages the trigger actuator lever  286 , continued rotation of the cam gear  18  in the first direction moves the one-way rotation stop  236  away from or out of engagement with the trigger  206  such that the trigger actuator lever  286  can rotate out of the way of the second cam  205  without affecting the engagement of the trigger  206  with the pawl  204 . This allows the second cam  205  to slide past the trigger actuator lever  286  without affecting the position of the trigger  206 , which must be positioned to engage the notches  254  and  233  as the cam lobe  207  of the first cam  203  moves the pawl from the first latched position to the second latched position as seen in  FIGS. 26-30 . 
         [0061]    During the opening operation of the latch  200 , the cam gear  218  starts from its initial starting position (see  FIGS. 32-35 ) and rotates in the second or reverse direction until the second cam  205  engages the trigger actuator lever  286 . Continued rotation of the cam gear  18  in the second direction moves the one-way rotation stop  236  into engagement with the trigger  206  such that the trigger actuator lever  286  cannot rotate relative to the trigger  206  with the result that the second cam  205  pushes the trigger  206  out of engagement with the pawl  204  so as to release the pawl  204  for rotation to the unlatched position as illustrated in  FIGS. 36-49 . 
         [0062]    During the opening operation of the latch  200 , the cam gear  218  starts from its initial starting position (see  FIGS. 32-33 ) and rotates in the second or reverse direction until the first cam  205  disengages the trigger from the pawl  204  to thus release the pawl  204  for rotation to the unlatched position. At this same time the cam lobe  207  of the first cam  203  can engage the elongated prong  314  of the pawl  204  to assist the pawl  204  toward the unlatched position if the progress of the pawl  204  under spring bias is impeded by, for example, a sticky door seal. The length of the second cam  205  is selected such that the trigger  206  is disengaged from the pawl  204  during opening before the first cam  203  can engage the pawl  204  and such that the trigger  206  will remain disengaged from the pawl  204  until the first notch  254  is beyond any possibility of engagement with the trigger  206 . 
         [0063]    A striker detector  318  is pivotally supported within the housing  202  by the support plate  215 . The striker detector  318  is provided with a torsion spring  244  that biases the striker detector  318  into occupying a first position coincident with the position of the rod-shaped portion  234  of the striker  308  when the striker  308  is captured by the pawl  204  and the pawl  204  is in the second latched position. Accordingly, when the striker  308  is captured by the pawl  204  and the pawl  204  is in the second latched position, the striker detector  318  is pushed to a second position by the striker  308 . A portion of the striker detector  318  registers with a third window  246  provided in the support plate  215 , at least when the striker detector is in its second position, to allow a sensor  320  to detect when the striker detector  318  is in its second position, which corresponds to the striker  308  being captured by the pawl  204  and the pawl  204  being in the second latched position. The sensor  320  generates a signal to the latch control circuit  235  when the striker detector  318  is in its second position to thus allow the latch control circuit  235  to detect whether or not the striker  308  is in the proper position when the pawl  204  is in the second latched position. In the illustrated example, the third window  246  is in the form of an arcuate, elongated slot. The sensor  320  is provided on the circuit board  230 . 
         [0064]    In the illustrated embodiment, the sensors  316 ,  320 ,  326 , and  332  are of the opto-electronic type. Each sensor  316 ,  320 ,  326 , and  332  includes a light emitter and a light detector. The pawl  204  is provided with a reflective surface at the end of the pin  219 , which is inserted into a hole in the pawl  204 . When the pawl  204  is in the first and second latched positions or any position therebetween, the reflective surface at the end of the pin  219  registers with the first window  221 . When the pawl  204  is in the first latched position, the reflective surface at the end of the pin  219  registers with the first sensor  332  to generate a signal to the latch control circuit  235  indicating that the pawl  204  is in the first latched position. When the pawl  204  is in the second latched position, the reflective surface at the end of the pin  219  registers with the second sensor  316  to generate a signal to the latch control circuit  235  indicating that the pawl  204  is in the second latched position. 
         [0065]    The cam lobe  207  has a raised platform  348  that is provided with a reflective surface  350 . When the cam gear  218  is in the initial or starting position, the reflective surface  350  registers with the second window  324 . When the cam gear  218  is in the initial or starting position, the reflective surface  350  registers with the third sensor  326  to generate a signal to the latch control circuit  235  indicating that the cam gear  218  is in the initial or starting position. 
         [0066]    The striker detector  318  has a raised platform  352  that is provided with a reflective surface  354 . When the striker detector  318  is in the second position, the reflective surface  354  registers with the third window  246 . When the striker detector  318  is in the second position, the reflective surface  354  registers with the fourth sensor  320  to generate a signal to the latch control circuit  235  indicating that the striker detector  318  is in the second position. 
         [0067]    The reflective surfaces can be provided by bright or reflective paint or metallization on the corresponding surfaces. It is possible to use other sensors such as Hall effect sensors or microswitches in place of the opto-electronic sensors used in the illustrative embodiment. If Hall effect sensors are used the reflective surfaces would be replaced by magnets embedded in the corresponding parts. If microswitches are used, all three windows would have to be in the shape of elongated arc-shaped slots with pins attached to the corresponding parts passing through the support plate  215  to actuate the microswitches on the circuit board  230 . 
         [0068]    In the illustrated embodiment, the end of the arm  268  of the pawl spring  262  is intended to be bent down into the opposite side of the same hole  356  in the pawl  204  that is occupied in part by the reflective pin  219 . Alternatively, the pin  219  can be made long enough to project out of the opposite end of the hole  356  in the pawl  204  for engagement by the arm  268  of the pawl spring  262 . 
         [0069]    The operation of the latch  200  will now be explained. With the latch initially in the fully unlatched configuration of  FIGS. 13-16 , as the panel  300  is moved to the closed position, the rod-shaped portion  234  of the striker  308  will be positioned or caught in the pawl slot  258  with the pawl  204  being moved to the first latched position relative to the support plate  215  as a result of the contact of the striker  308  with the pawl  204 . The pawl  204  is now in the first latched position relative to the support plate  215  as illustrated in  FIGS. 21-26 . The trigger  206  is in its first engaged position relative to the support plate  215  and retains the pawl  204  in its first latched position. The cam lobe  207  of the cam gear  218  is in its initial position shown in  FIGS. 23-24  where it does not contact the pawl  204 . As shown in  FIG. 23 , when the pawl  204  reaches the first latched position a pin  219  carried by the pawl communicates the position of the pawl  204  through the arc-shaped slot  221  in the support plate  215  to the sensor  332  that is mounted on the circuit board  230  on the side of the support plate  215  opposite the pawl  204 . Once the sensor  332  detects that the pawl  204  is in the first latched position, a signal is generated to an electronic latch control circuit  235  (shown diagrammatically), that may be located remotely or provided on the circuit board  230 , that controls the current supplied to the motor  210 , and in response the control circuit  235  causes the supply of electrical current to the motor  210  with a first polarity to cause the rotation of the cam gear  218  in a first direction from its start position illustrated in  FIGS. 23-30  to the position illustrated in  FIGS. 29-30 . During this movement of the cam gear  218 , the cam lobe  207  of the cam gear  218  engages the elongated prong  314  of the pawl  204  and thus rotates the pawl  204  to its second latched position relative to the housing  202 . At this point the trigger  206  engages the pawl  204  to retain the pawl  204  in the second latched position. The motor  210  continues to be energized until the cam gear  218  rotates back to its initial or starting position. At that point, the sensor  326  detects that the cam gear  218  is in its initial position and signals the control circuit  235  to shut off electrical current to the motor  210 , which stops further rotation of the cam gear  218 . The latch  200  now locks the panel  300  in its closed position. As the pawl  204  is rotated to its second latched position, a sealing gasket (not shown) is compressed to form a seal between the panel  300  and opening of the compartment closed off by the panel  300 . 
         [0070]    If normal closing is blocked, for example by items being caught between the panel  300  and the compartment opening, after a predetermined time without a signal from the sensor  326 , the control circuit  235  reverses the current to the motor to disengage the trigger  206  from the pawl  204  by the reverse movement of the second cam  205  and the panel  300  is released and the latch  200  is returned to the initial fully unlatched configuration. 
         [0071]    To open the latch  200  the motor  210  is energized by the user using a remotely located switch (not shown). The cam gear  218  rotates from the initial position of  FIGS. 32-33  in a second direction, opposite the first direction, to bring the second cam  205  into contact with the trigger actuator lever  286  as shown in  FIGS. 36-39 . The rotation of the cam gear  218  in the second or reverse direction causes the second cam  205 , acting via the trigger actuator lever  286 , to rotate the trigger  206  out of engagement with the pawl  204  in order to release the pawl  204  for rotation to the unlatched position as shown in  FIGS. 38-43 . The striker  308  is now released and the panel  300  can be opened. The motor  210  remains energized until the cam gear  218  is once again in its initial position as detected by the sensor  326 . When the sensor  326  senses that the cam lobe  207 , and consequently the cam gear  218 , has returned to its initial position, the sensor  326  signals the control circuit  235  to stop energizing the motor. 
         [0072]    Referring to  FIGS. 31-33 , if the pawl  204  is moved to the second latched position as detected by the sensor  316 , while the striker detector  318  does not indicate that the striker  308  is captured by the pawl  204 , then the control circuit  235  reverses the current to the motor to disengage the trigger  206  from the pawl  204  by the reverse movement of the second cam  205  and the panel  300  is released and the latch  200  is returned to the initial fully unlatched configuration. If the motor  210  or associated circuitry fail with the latch fully latched and the panel  300  closed, the trigger lever  284  is provided with a hole  322  that allows a cable (not shown) to be attached to the trigger lever  284  as a back-up mechanical release mechanism that will be operated by a lever (not shown) from the interior of the vehicle. The cable can then be pulled to disengage the trigger  206  from the pawl  204  in order to release the pawl  204 , and consequently the striker  308 , such that the panel  300  can then be opened. 
         [0073]    If the panel  300  is closed on the inoperable latch  200 , the striker  308  can engage and move the pawl  204  to the first latched position where the pawl  204  is held by the trigger  206  and the striker  308  is captured by the pawl slot  258 . This first latched configuration is illustrated in  FIGS. 19-20 . This arrangement allows the panel  300  to be secured in a near closed position until the vehicle can be taken in for service. 
         [0074]    During the operation of the latch  200 , the latch control circuit  235  also continuously monitors the current supplied to the motor  210 . If a sudden rise in the motor current is detected due to an unexpected load during closing, the rotation of the cam gear  218  is reversed to release the latch pawl  204  as a safety measure. 
         [0075]    The bushing  500  is provided for supporting the end of the motor shaft  220 . In the assembly views the various springs are only shown diagrammatically. 
         [0076]    It is to be understood that the present invention is not limited to the embodiments disclosed above, but includes any and all embodiments within the scope of the appended claims.