Patent Publication Number: US-2010127511-A1

Title: Vehicle door latch having a power lock-unlock mechanism

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 12/324,103 filed on Nov. 26, 2008, the disclosure of which is incorporated by reference herein, in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     An automotive closure, such as a door for an automobile passenger compartment, is hinged to swing between open and closed positions and conventionally includes a door latch that is housed between inner and outer panels of the door. The door latch functions in a well known manner to latch the door when it is closed and to lock the door in the closed position or to unlock and unlatch the door so that the door can be opened manually. 
     In general terms, the door latch has a forkbolt that engages a striker in the door jamb to latch the door when it is closed and a spring biased detent lever that engages and holds the forkbolt in the latched position. The door latch also typically has a release mechanism for moving the detent to a position releasing the forkbolt so that the door can be unlatched and opened and a lock-unlock mechanism for disabling the release mechanism to prevent unauthorized unlatching of the door. U.S. Pat. No. 6,053,543 granted to Arabia, Jr. et al. on Apr. 25, 2000, which is incorporated by reference herein, shows a typical door latch, as known in the prior art. 
     A door latch also includes an independent lock and unlock mechanism sometimes this includes an intermittent lever and the door latch is power operated. Generally, a bell crank lever engages a screw that rotates when driven by an electric motor. The rotation of the screw causes an axial movement that ultimately drives a slide up and down. The slide is connected to a bell crank lever having multiple moving parts and pivot points for allowing a detent in and out of engagement with a forkbolt, causing the forkbolt to move between a latched and an unlatched position. 
     A door lock, especially when placed in a vehicle, should be robust in that it is capable of operating in extreme environments and capable of operating for years over multiple duty cycles. It should also be capable of a manual lock or un-lock without having to back-drive the motor or other power operated devices. 
     SUMMARY OF THE INVENTION 
     The present invention provides a simple power operated lock-unlock mechanism. It has less moving parts and pivots than other latches. This assures that the lock is capable of performing in extreme environments for many years. The mechanism also provides a lost motion aspect that allows the lock-unlock mechanism to be operated manually in the event of power failure to the power operated device. 
     A door latch having a forkbolt that moves between a latched position and an unlatched position is provided. It includes a detent for holding the forkbolt in the latched position, and a power operated lock-unlock mechanism for moving the door latch to a lock or unlock position. It further comprises a first rotatable locking lever moveable from a locked position to an unlocked or locked position and in operable communication with the detent through an intermittent lever; a second rotatable locking lever in operable communication with the first rotatable locking lever; a motor driven actuator engaging the second rotatable locking lever; and an actuator pin disposed between the motor driven actuator and the second rotatable locking lever for rotating the second rotatable locking lever. 
     In another aspect of the invention, a power operated locking mechanism for a door latch is provided. It comprises a first rotatable locking lever moveable from a locked position to an unlocked position. A second rotatable locking lever in operable communication with the first rotatable locking lever and having a first portion extending therefrom is also provided. A motor driven actuator including an actuator pin extending therefrom is provided. The actuator pin engages the second rotatable locking lever at the first portion so as to allow movement of the second rotatable locking lever without movement of the motor driven actuator. 
     In yet another aspect of the invention, a door latch having a forkbolt that moves between a latched position and an unlatched position is provided together with a detent for holding the forkbolt in the latched position, and a power operated lock-unlock mechanism for moving the door latch to a lock or unlock position. It includes a first rotatable locking lever moveable from a locked position to an unlocked position, an intermittent lever in operable communication with the detent and an unlatching lever. A second rotatable locking lever is in operable communication with the first rotatable locking lever. An axially extending motor driven actuator includes an actuator pin having a portion extending from the actuator at an angle from the axis, the actuator pin engaging the second rotatable locking lever. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a cross sectional view showing one aspect of the present invention. 
         FIG. 2  is a pictorial view of the door latch, in a unlocked position, in accordance with the present invention; 
         FIG. 3  is a pictorial view of the door latch of  FIG. 2 , in a locked position, in accordance with the present invention; and 
         FIG. 4  is a pictorial view showing another aspect of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIGS. 1 through 4 , where the invention will be described with reference to specific embodiments, without limiting same, a door latch  10  is located within a housing enclosure  12 . The housing  12  includes two flanged studs  14  and  15  that are inserted through the housing  12 , and capture both a face plate and a back cover (not shown) by being flanged over holes in the face plate and back cover to form a forward compartment  17  and a rearward compartment  18  of door latch  10 . 
     Door latch  10  has a latch mechanism comprising a forkbolt  21  and a cooperating detent  22  that are located in the forward compartment  17  and pivotally mounted on the forward portions of studs  15  and  14 , respectively. Forkbolt  21  is biased clockwise by a compression spring  23  that is disposed in a curved slot (not shown) in housing  12  behind forkbolt  21 . Spring  23  engages a lateral lug  30  of forkbolt  21  at a first end  31  and an end wall (not shown) of the curved slot at a second end  32 . 
     Detent  22  engages a lateral pin  34  through an opening  25  within the detent  22  that extends between a first side  26  and a second side  27  of the detent. Lateral pin  34  is rotatable within opening  25  and extends through a housing slot  42  that defines a travel path  46  for lateral pin  34  and into the rearward compartment  18 . Door latch  10  has a release mechanism  51  for manually releasing or unlatching the latching mechanism. Specifically, releasing mechanism includes an unlatching lever  52 , shown retained on first stud  14  and being adapted to rotate about first stud  14 . Unlatching lever  52  has an intermittent lever slot  53  extending between rear side  54  and front side  55  of the unlatching lever  52 . Engaging intermittent lever slot  53  and pivotably engaging unlatching lever  52  is an intermittent lever  60 . An intermediate portion  61  of intermittent lever  60  includes lateral pin  34 . Extending therefrom is a first arm portion  62  having a first lever pin  63  that engages intermittent lever slot  53 . A second arm portion  64  also extends from intermediate portion  61 . Extending from second arm portion  64  is a second lever pin  65  that engages a slot  67  within a power operated lock-unlock mechanism  110 , shown in an exemplary embodiment herein as a three-piece power operated lock-unlock mechanism  110 . 
     As is well known and can be seen from the Figures, detent  22  engages forkbolt  21  at a primary latch shoulder  36  and holds forkbolt  21  in a primary latched position, against the bias of springs (not shown). Detent  22  is rotated counter-clockwise from a latched position and out of latched engagement with the forkbolt  21  to a release or unlatched position when the release mechanism is operated. This releases forkbolt  21  so that it is free to rotate in a conventional manner from the latched position to the unlatched position allowing a vehicle door to be opened. In  FIGS. 2 and 3 , forkbolt  21  is still in the primary latched position. 
     Door latch  10  includes the power operated lock-unlock mechanism  110 . Power operated lock-unlock mechanism  110  includes a first rotatable locking lever (or upper locking lever)  111  movable from a resting or unlocked position shown in  FIG. 2  to a locked position shown in  FIG. 3 . As shown, first rotatable locking lever  111  is in operable communication with detent  22  through intermittent lever  60 . Specifically, second lever pin  65  slidingly engages a slot  112  located within rotatable locking lever  111 . Rotatable locking lever  111  is capable of pivotable movement about stud  15  and is located within rearward compartment  18  of housing  12 . Locking lever  111  also includes shoulder portions  114  and  115  that engage a second rotatable locking lever (or lower locking lever)  121 . 
     Second rotatable locking lever  121  includes a saucer portion  122  through which stud  15  extends, thus also allowing rotation of second locking lever  121 . The rearward face  123  of saucer portion  122  supports and is in sliding engagement with a forward facing face of locking lever  111 . Extending both rearward and outwardly from the saucer portion  122  is a handle portion  124  having a groove  125  therein that is open at a first end  126  and defined by a finger  127  at its opposite end. A resilient member, such a compression spring  131  sits within groove  125  with one end of spring  131  bearing against finger  127  and the other end or spring  131  bearing against shoulder portion  115 . 
     Extending from the handle portion  124  of locking lever  121  is a fork portion  141  having tines  142  and  143 . A motor  150  that includes a drive gear  151  drives an actuator gear  152  that causes an actuator to rotate, in this case screw stock  153  having threads thereon. Threaded on actuator  153  is an actuator and nut  154  having an actuator pin  155  extending therefrom. Actuator pin  155  extends between tines  142  and  143  of fork portion  141 . Actuator pin  155  includes a collar  156  for engaging at least one, and as shown, the legs of two resilient members comprising torsion springs  161  and  162 . Torsion springs  161  and  162  keep nut  154  and actuator pin  155  centered. Springs  161  and  162  are seated within spring seats  163  and  164 , respectively of housing  12 . Actuator  153  sits in a well  165  of housing  12 , which includes opposite interior sides  166  and  167 . The outside diameter of nut  154  bears against interior sides  166  and  167  in such a manner that rotation of actuator  153  causes nut  154 , shown in phantom in  FIGS. 2 and 3 , to move axially along the threads of actuator  153  and thus retains actuator pin in the upright position shown in  FIGS. 2 and 3 . 
     The actuator pin  155  has an upper portion that has an outside diameter. Tines  142  and  143  of fork portion  141  are adapted to engage actuator pin  155  at its upper portion when actuator pin  155  moves axially. In an exemplary embodiment, actuator pin  155  has an outside diameter and tines  142  and  143  have a first distance therebetween. The first distance is greater than the outside diameter plus the travel of pin  155  between the locked and unlocked position. 
     Movement of the door lock from the unlocked position of  FIG. 2  to the locked position of  FIG. 3  will now be described. Driving motor  150  causes drive gear  151  to rotate, which in turn drives actuator gear  152  and threaded actuator  153 , shown as a jackscrew. As threaded actuator  153 , rotates nut  154  translates axially along threaded actuator  153 , thus moving actuator pin  155  in an axial direction—shown in phantom in  FIGS. 2 and 3 . This axial movement causes one of tines  142  or  143  to contact the upper portion of actuator pin  155 , thus causing fork portion  141  and locking lever  121  and finger  127  to bear against compression spring  131  within groove  125 , the other end of compression spring  131  contacting shoulder portion  115  of rotatable locking lever  111 . Clockwise rotation of rotatable locking lever  111  allows second lever pin  65  to move within the slot  112 , so that the latching mechanism can work. Thus the latching mechanism can be operated to move intermittent lever  60  out of locking engagement with the primary latch shoulder  36  of forkbolt  21  by causing lateral pin  34  to bear within opening  25 . Compression spring  23  causes forkbolt  21  to rotate clockwise to an unlatched position. During this movement, striker pin  90  moves out of a rear portion  92  of throat  91 , thus releasing striker pin  90 . 
     In a like manner, when the door latch  10  is in an unlatched and unlocked condition, forkbolt  21  is poised to receive a striker pin  90 . When a door having latch  10  is shut, the striker pin  90  enters the throat  91  of forkbolt  21 , engages the rear portion  92  of throat  91  and rotates forkbolt  21  counterclockwise against the bias of compression spring  23  until forkbolt  21  is rotated to the primary latched position shown in  FIGS. 1 and 2 , where forkbolt  21  captures striker pin  90  in throat  91 . Forkbolt  21  is held in the latched position by catch  94  of detent  22  engaging primary latch shoulder  36  of forkbolt  21 . The motor  150  then can be actuated by a secondary operation in order to lock the door latch  10 . While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description.