Abstract:
In one aspect, the invention is directed to a closure latch for a vehicle door. The closure latch includes a ratchet movable between an open position and a closed position, a first door release lever operatively connected to the ratchet, a second door release lever, and a lock lever movable along a lock lever path including a first lock lever position wherein the second door release lever is operatively disconnected from the first door release lever, a second lock lever position wherein the lock lever operatively connects the second door release lever to the first door release lever, and a third lock lever position wherein the lock lever carries out an additional function.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This applicaiton is a National Stage of International Application No. PCT/CA2008/01807, filed on Oct. 10, 2008, which claims priority to and the benefit of U.S. Provisional Applicaiton No. 60/978,800 filed Oct. 10, 2007 and U.S. Provisional Application No. 61/075,379 filed Jun. 25, 2008. The entire disclosure of each of the above applications is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a closure latch for a vehicle door, and more particularly to a closure latch for a vehicle door equipped with a passive entry feature. 
     BACKGROUND OF THE INVENTION 
     Passive entry systems for vehicles are provided on some vehicles to permit a vehicle user who is in possession of the vehicle key to simply pull the door handle and open the door without the need to introduce the key into a keyhole in the door. The key (more particularly, the key fob) is equipped with an electronic device that communicates with the vehicle&#39;s on-board control system to authenticate the user. When the user pulls the door handle to indicate that he/she wishes entry into the vehicle, it would be advantageous for the vehicle to unlock the door relatively quickly so that he/she does not have to wait an unduly long time before being permitted to open the door. 
     SUMMARY OF THE INVENTION 
     In one aspect, the invention is directed to a closure latch for a vehicle door. The closure latch includes a ratchet movable between an open position and a closed position, a first door release lever operatively connected to the ratchet, a second door release lever, and a lock lever movable along a lock lever path including a first lock lever position wherein the second door release lever is operatively disconnected from the first door release lever, a second lock lever position wherein the lock lever operatively connects the second door release lever to the first door release lever, and a third lock lever position wherein the lock lever carries out an additional function. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be described by way of example only with reference to the attached drawings, in which: 
         FIG. 1 a    is an elevation view of a portion of a closure latch for a vehicle door in accordance with an embodiment of the present invention, showing a lock lever in a first position; 
         FIG. 1 b    is a plan view of another portion of the vehicle latch shown in  FIG. 1 a    with some components shown as transparent for greater clarity; 
         FIG. 1 c    is a magnified perspective view of a portion of the closure latch shown in  FIG. 1   b;    
         FIG. 1 d    is an elevation view of the portion of the closure latch shown in  FIG. 1   c;    
         FIG. 1 e    is another magnified perspective view of the portion of the closure latch shown in  FIG. 1 b    with some components shown as transparent for greater clarity; 
         FIG. 2 a    is an elevation view of the closure latch shown in  FIG. 1 a   , showing the lock lever in a second position; 
         FIG. 2 b    is a plan view of the closure latch shown in  FIG. 2   a;    
         FIG. 2 c    is a magnified perspective view of a portion of the closure latch shown in  FIG. 2   b;    
         FIG. 2 d    is an elevation view of the portion of the closure latch shown in  FIG. 2   c;    
         FIG. 2 e    is another magnified perspective view of the portion of the closure latch shown in  FIG. 2 b    with some components shown as transparent for greater clarity; and 
         FIG. 3  is an elevation view of the closure latch shown in  FIG. 1 a   , showing the lock lever in a third position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is made to  FIGS. 1 a  and 1 b   , which show portions of a closure latch  10  for a door (not shown) of a vehicle (not shown), in accordance with an embodiment of the present invention. 
     The closure latch  10  includes a ratchet  12  ( FIG. 1 b   ), a pawl  14  ( FIG. 1 b   ), a first door release lever  16  ( FIG. 1 c   ), a second door release lever  18  ( FIG. 1 b   ), a lock link  20  ( FIG. 1 b   ), a lock lever  22  ( FIG. 1 a   ), a lock lever actuator  24  ( FIG. 1 a   ) and a lock knob assembly  25  (a small portion of which is shown in  FIG. 1 a   ). 
     Referring to  FIG. 1 b   , the ratchet  12  is movable between a closed position ( FIG. 1 b   ) wherein the ratchet  12  retains a striker (not shown) mounted on the body (not shown) of the vehicle and an open position wherein the ratchet  12  is unengaged with the striker. A ratchet biasing member  26  such as a suitable spring may be provided to bias the ratchet  12  towards the open position. 
     The pawl  14  is movable between a ratchet locking position ( FIG. 1 b   ) wherein the pawl  14  holds the ratchet  12  in the closed position, and a release position wherein the pawl  14  permits the ratchet  12  to move to its open position. A pawl biasing member  28  such as a suitable spring may be provided to bias the pawl  14  towards the ratchet locking position. 
     The first door release lever  16  is operatively connected to the ratchet  12  for movement from the closed position to the open position. The first door release lever  16  may be operatively connected to the ratchet  12  in any suitable way, such as by direct mechanical engagement (See  FIG. 1 e   ). The first door release lever  16  may be movable from a rest position to a door release position (not shown) wherein it moves the pawl  14  to the release position (not shown) so that the ratchet  12  can be moved from the closed position to the open position under the urging of the ratchet biasing member  26 . 
     A first door release lever biasing member  30 , such as a suitable spring, may be provided to bias the first door release lever  16  towards its rest position. Instead of having a first door release lever biasing member  30  that is dedicated solely to moving the first door release lever  16  to its rest position, it is possible for the pawl  14  to move the first door release lever  16  to its rest position, during movement of the pawl  14  to its ratchet locking position under the urging of the pawl biasing member  28 . Thus, the pawl biasing member  28  may act as a first door release lever biasing member  30  as shown in  FIG. 1   b.    
     The first door release lever  16  ( FIG. 1 c   ) has a first lock link engagement surface  32  which is configured to be engaged by the lock link  20 . 
     The second door release lever  18  ( FIG. 2 c   ) is operatively connectable to the first door release lever  16 . The second door release lever  16  may be operatively connectable to the first door release lever  16  in any suitable way, such as through the lock link  20 . The second door release lever  18  includes a second lock link engagement surface  34  that is positioned to engage the lock link  20 . The second door release lever  18  may be movable from a rest position ( FIG. 1 c   ) to a door release position (not shown), which is described further below. 
     A second door release lever biasing member  36 , such as a suitable spring, may be provided to bias the second door release lever  18  towards its rest position. 
     The second door release lever  18  may be moved from its rest position to its door release position by one or more means, such as by movement of an outer door handle (not shown) on the outside of the vehicle door (not shown). 
     The lock link  20  may be movable between a first lock link position  20  ( FIGS. 1 a -1 e   ) wherein the lock link  20  is disengaged from the first door release lever, and a second lock link position ( FIGS. 2 a -2 e   ) wherein the second door release lever  18  is operatively connected to the first door release lever  16  through the lock link  20 . More specifically, when a person pulls the outside door handle the second door release lever  18  is moved from its rest position to its door release position and moves a first end  38  of the lock link  20  with it. If the lock link  20  is in the first position ( FIGS. 1 a -1 e   ) and the person pulling the vehicle door handle is not in possession of an electronic vehicle key, then the first end  38  of the lock link  20  will sweep past the first lock link engagement surface  32  during movement of the second door release lever  18  to its door release position. As a result, the first door release lever  16  will not be moved to its door release position and the ratchet  12  will remain in its closed position. 
     When the lock link  20  is in the second position ( FIGS. 2 a -2 e   ) and the second door release lever  18  is moved from its rest position to its door release position, the first end  38  of the lock link  20  is positioned to engage the first lock link engagement surface  32  and will move the first door release lever  16  to its door release position (not shown) thereby moving the pawl  14  and ratchet  12  to open the vehicle door. 
     The lock link  20  may be biased towards the second lock link position ( FIG. 2 b   ), by any suitable means, such as by a suitable spring  41 . 
     The second end of the lock link  20  is shown at  40  in  FIG. 1 a   . At the second end  40 , the lock link  20  has a guide pin  42  and a lock lever engagement member  44 . The guide pin  42  engages a guide channel  46  that is fixedly connected to a latch housing member  48 . The guide channel  46  and the guide pin  42  together guide the movement of the lock link  20  between its first and second positions. 
     The guide pin  42  is rotatable within the guide channel  46  ( FIG. 1 b   ). This permits the lock link  20  to pivot as necessary during movement of the second door release lever  18  between its rest position and its door release position. 
     The lock lever engagement member  44  is engageable by the lock lever  22  ( FIG. 1 a   ). The lock lever  22  is movable between a first position ( FIG. 1 a   ), a second position ( FIG. 2 a   ) and a third position ( FIG. 3 ). In the first position, the lock lever  22  holds the lock link  20  in the first lock link position ( FIGS. 1 a -1 e   ). Additionally, when the lock lever  22  is in the first position, the lock knob assembly  25  is in a locked lock knob assembly position. When the lock lever  22  is in the second position ( FIG. 2 a   ), it permits the lock link  20  to move to the second lock link position ( FIG. 2 b   ) under the urging of the lock link biasing member  41  ( FIG. 2 b   ), thereby providing an operative connection from the second door release lever  18  to the first door release lever  16 . Additionally, when the lock lever  22  is in the second position, the lock knob assembly  25  may be moved from the locked lock knob assembly position to an intermediate position ( FIG. 2 a   ) on the way to an unlocked lock knob assembly position ( FIG. 3 ). 
     As the lock lever  22  moves away from the second position towards the third position, it may disengage from the lock link  20 . The movement of the lock lever  22  to the third position causes the lock knob assembly  25  to move to the unlocked lock knob assembly position. 
     Rotation of the lock lever  22  from the first position towards the third position is in an unlocking direction. Rotation of the lock lever  22  from the third position towards the first position is in a locking direction. 
     The lock lever actuator  24  moves the lock lever  22  along the lock lever path between the first and third positions. Referring to  FIG. 1 a   , the lock lever actuator  24  includes a motor  50  and a linkage  52  that operative connects the motor  50  to the lock lever  22 . The linkage  52  may include a worm gear  54  driven directly by the motor  50 , a first spur gear  56  driven by the worm gear  54 , a second spur gear  57  driven by the first spur gear  56  and a lobed member  58  with at least one lobe  60  integrally connected to the second spur gear  57 . A lobe receiving member  62  may be included as part of the lock lever  22  for receiving the lobe  60  and being driven thereby. 
     The movement of the lock knob assembly  25  between its locked and unlocked positions may require significantly more torque than the movement of the lock link  20  between its first and second positions. As a result, there is a relationship between the strength (and therefore cost) of the motor  50 , the effective torque increase that takes place in the linkage  54  and the time required to carry out the movement of the lock knob assembly  25  between its locked and unlocked positions. 
     When the vehicle is locked and a person who is in possession of a proximity-actuated key (not shown) lifts the outside door handle of the vehicle, the initial movement of the outside door handle instructs the vehicle&#39;s on-board electronics to actuate the motor  50 . The motor  50  causes the rotation of the lock lever  22  from the first lock lever position ( FIG. 1 a   ) through the second lock lever position ( FIG. 2 a   ) to the third lock lever position ( FIG. 3 ). The movement of the lock lever  22  from the first lock lever position to the second lock lever position causes the lock link  20  to move from the first lock link position to the second lock link position thereby operatively connecting the second door release lever  18  to the first door release lever  16 . This process of actuating the motor  50  until the second door release lever  18  is operatively connected to the first door release lever  16  preferably takes place within a selected period of time, which may be, for example, less than 50 milliseconds. 
     Because the lock link  20  is disengageable from the lock lever  22  (eg. during movement of the lock lever  22  between the second and third lock lever positions) the movement of the lock link  20  and the movement of the lock knob assembly  25  are independent of one another. By having the movements of the lock link  20  and the lock knob assembly  25  be independent from one another, the movement of the lock link  20  to its second position can be effected quickly so as to reduce the time to unlock the vehicle door, while the movement of the lock knob assembly  25  can remain longer so as to not require an undesirably strong (and therefore relatively expensive) motor  50 . Preferably, the time required to unlock the vehicle door can be short enough so as to permit a person to open the door in one continuous motion without having to pause midway to permit the door to unlock. 
     To lock the vehicle door, the motor  50  is rotated so that the lock lever  22  moves from the third lock lever position through the second lock lever position to the first lock lever position. Movement of the lock lever  22  from the third lock lever position to the second lock lever position moves the lock knob assembly  25  partway from the unlocked lock knob assembly position towards the locked lock knob assembly position. When the lock lever  22  is in the second lock lever position it has reengaged with the lock link  20 . It will be understood that the point at which the lock link  20  is engaged by the lock lever  22  does not necessarily have to correspond to the point at which the lock link  20  operatively connects the second door release lever  18  to the first door release lever  16 . In other words, the point at which the lock link  20  is engaged by the lock lever  22  may be somewhere suitable between the second and third lock lever positions. 
     Movement of the lock lever  22  from the second lock lever position to the first lock lever position moves the lock link  20  from the second lock link position to the first lock link position, thereby operatively disconnecting the second door release lever  18  from the first door release lever  16 . 
     It has been shown for the lock lever  22  to control the operative connection between the second and first door release levers  18  and  16  via the lock link  20 . It is alternatively possible however, for the lock lever  22  to control the operative connection between the second and first door release levers  18  and  16  in some other way. For example, an alternative embodiment may omit the lock link and an arm on the lock lever  22  itself may be selectively positionable in between the second and first door release levers  18  and  16  based on the position of the lock lever. 
     While the above description constitutes a plurality of embodiments of the present invention, it will be appreciated that the present invention is susceptible to further modification and change without departing from the fair meaning of the accompanying claims.