Patent Publication Number: US-8522583-B2

Title: Door latch with emergency lock actuator and ‘impatient passenger’ feature

Description:
FIELD OF THE INVENTION 
     The present invention relates to a closure latch for a vehicle door, and more particularly to a closure latch having both an emergency lock actuator and an ‘impatient passenger’ feature. 
     BACKGROUND OF THE INVENTION 
     Some vehicle door closure latches equipped with a primary lock actuator (eg. a power lock actuator), also include an emergency lock actuator that can be used in the event of a failure of the primary lock actuator. Some latches also includes other features, such as, for example, an ‘impatient passenger’ feature. Such a feature permits the latch to be unlocked by the lock actuator motor even if an ‘impatient passenger’ had lifted the door handle prior to the vehicle owner actuating the motor. Such features, while beneficial to have, increase the cost and complexity of the latch, however. 
     It would be beneficial to provide a closure latch that provided these features, but that was relatively less complex. 
     SUMMARY OF THE INVENTION 
     In one aspect, the invention is directed to a closure latch for a vehicle door. The closure latch includes an emergency lock actuator to permit a person to unlock the door in the event that the power lock actuator is unusable. The latch also includes an ‘impatient passenger’ feature, which permits the doors to be unlocked using the remote keyless-entry feature on the key fob even in a situation where an ‘impatient passenger’ had prematurely lifted the door handle of the vehicle. In some prior art latches, such an action by an ‘impatient passenger’ would prevent the drive motor on the latch from unlocking the latch, thereby necessitating the owner to press the unlock button on the key fob a second time. There is some overlap in the components that used for the ‘impatient passenger’ feature and the components used for the emergency lock actuator, thereby reducing cost and complexity of the latch. 
     In a particular embodiment, the invention is directed to a closure latch for a vehicle door. The latch includes a ratchet, a pawl, an outsider door release lever, a lock link and a lock link driver. The ratchet is movable between an open position and a closed position and is biased towards the open position. The pawl is movable between a ratchet locking position wherein the pawl holds the ratchet in the closed position and a ratchet release position wherein the pawl permits the ratchet to move to the open position. The pawl is biased towards the ratchet locking position. The outside door release lever is movable between a home position and an actuated position. The outside door release lever is biased towards the home position. The lock link is movable between an unlocking position and a locking position. The lock link is biased towards the unlocking position by a lock link biasing member. When the lock link is in the unlocking position movement of the outside door release lever to the actuated position drives the pawl to the ratchet release position. When the lock link is in a locking position the outside door release lever is operatively disconnected from the pawl and movement of the outside door release lever to the actuated position prevents movement of the lock link from the locking position to the unlocking position. The lock link driver is movable between an unlocking position and a locking position. The lock link driver is operatively connected to the lock link through a slot-and-pin connection such that when the lock link driver is in the locking position the lock link is in the locking position, and when the lock link driver is in the unlocking position the lock link is urged towards the unlocking position by the lock link biasing member. When the lock link is prevented from movement to the unlocking position by the outside door release lever in the actuated position, movement of the outside door release lever to the home position permits movement of the lock link to the unlocking position under the urging of the lock link biasing member. The lock link driver includes a manual rotation feature thereon for manual rotation of the lock link driver at least to the unlocking position, wherein the manual rotation feature is accessible from the exterior of the vehicle door. 
     In another aspect, the invention is directed to a closure latch for a vehicle door that includes an emergency lock actuator that is integrated into the lock/unlock chain (ie. the chain of components involved in locking and unlocking the latch) without necessitating the need for many additional components. 
    
    
     
       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  is a perspective view of a closure latch for a vehicle door in accordance with an embodiment of the present invention; 
         FIG. 2  is a magnified perspective view of the closure latch shown in  FIG. 1 , showing an outside door release lever in a home position, a lock link in an unlocking position and a lock link driver in an unlocking position; 
         FIGS. 3   a  and  3   b  are perspective views illustrating the operation of the outside door release lever when the lock link is in a locking position; 
         FIGS. 4   a  and  4   b  are perspective views of the closure latch shown in  FIG. 2 , illustrating the operation of an ‘impatient passenger’ feature; and 
         FIGS. 5   a  and  5   b  are perspective views of the closure latch shown in  FIG. 2 , illustrating the operation of an emergency lock actuator. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is made to  FIG. 1 , which shows a closure latch  10  for a vehicle door  11  of a vehicle  13 , in accordance with an embodiment of the present invention. Referring to  FIG. 2 , the closure latch  10  includes a ratchet  12 , a pawl  14 , an outside door release lever  16 , a lock link  18 , a lock link driver  20 , a power lock actuator  22 , an emergency lock actuator  24 , and an ‘impatient passenger’ structure  26 . The closure latch  10  may include other elements not described above, such as, for example, an inside door release lever, which are, in the embodiment shown in the figures, not directly related to the invention. 
     The ratchet  12  is movable between a closed position ( FIG. 2 ) wherein the ratchet  12  retains a striker  27  mounted on the body (not shown) of the vehicle, and an open position wherein the ratchet  12  is unengaged with the striker  27 . A ratchet biasing member  28  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. 2 ) wherein the pawl  14  holds the ratchet  12  in the closed position, and a ratchet release position wherein the pawl  14  permits the ratchet  12  to move to its open position. A pawl biasing member  30  such as a suitable spring may be provided to bias the pawl  14  towards the ratchet locking position. 
     The outside door release lever  16  is movable by a cable from an outside door handle between a home position and an actuated position, and is biased towards the home position by an outside door release lever biasing member  32 . 
     The lock link  18  is movable between an unlocking position ( FIG. 2 ) and a locking position ( FIG. 3   a ), and is biased towards the unlocking position by a lock link biasing member  34 . When the lock link  18  is in the unlocking position, it operatively connects the outside door release lever  16  to the pawl  14 , so that actuation of the outside door release lever  16  from the home position to the actuated position drives the pawl  14  to move to its ratchet release position. 
     When the lock link  18  is in the locking position, shown in  FIG. 3   a , the outside door release lever  16  is operatively disconnected from the pawl  14 . As a result when the outside door release lever  16  is moved from its home position ( FIG. 3   a ) to its actuated position (shown in  FIG. 3   b ), the outside door release lever  16  does not drive the pawl  14  from its ratchet locking position (ie. it permits the pawl  14  to be in the ratchet locking position). 
     The lock link  18  has an arm  36  that is captured in a slot  38  of the lock link driver  20 . The lock link driver  20  is pivotable between an unlocking position ( FIG. 2 ) and a locking position ( FIG. 3   a ). The arm  36  is biased to a first end  40  of the slot  38  by the lock link biasing member  34 . 
     Referring to  FIG. 2 , movement of the lock link driver  20  can be carried out either by the power lock actuator  22  or the emergency lock actuator  24 . The power lock actuator  22  may include any suitable structure permitting it to be operatively connected to the lock link driver  20 . In the exemplary embodiment shown in  FIG. 2 , the power lock actuator  22  includes a bidirectional electric motor  42  which drives a worm gear  44 , which in turn drives a sector gear member  46 . The sector gear member  46  has thereon a pair of arms  48   a  and  48   b , which engage a pin  50  on the lock link driver  20  thereby operatively connecting the power lock actuator  22  to the lock link driver  20  and thus to the lock link  18 . When the motor  42  drives the worm gear  44  in a first worm gear direction, the worm gear  44  in turn drives the sector gear member  46  in a first sector gear direction (clockwise in the view shown in  FIG. 2 ), which drives the lock link driver  20  (through engagement with the pin  50 ) to the locking position ( FIG. 3   a ), thereby driving the lock link  18  to its locking position shown in  FIG. 3   a . When the motor  42  drives the worm gear  44  in a second worm gear direction (which is opposite to the first worm gear direction), the worm gear  44  in turn drives the sector gear member  46  in a second sector gear direction (which is opposite to the first sector gear rotation), which in turn drives the lock link driver  20  (through engagement with the pin  50 ) to the unlocking position ( FIG. 2 ), thereby urging the lock link  18  towards its unlocking position by means of the lock link biasing member  34 . 
     With reference to  FIG. 4   a , if the outside door release lever  16  is in the actuated position while the lock link driver  20  is moved to its unlocking position, the outside door release lever  16  prevents the lock link  18  from moving to the unlocking position. In such a situation, until the outside door release lever  16  is released and thereby permitted to move back to its home position, the lock link  18  remains in its locking position. In such a situation, it can be seen in  FIG. 4   a  that the arm  36  is no longer at the first end  40  of the slot  38 . The slot  38  thus permits the lock link driver  20  to be moved to its unlocking position even in a situation when the lock link  18  is prevented from leaving the locking position by the outside door release lever  16 . An example of when this situation can occur is described further below. 
     With reference to  FIG. 4   b , when the outside door release lever  16  is finally released from its actuated position and is permitted to move back to its home position, the lock link  18  is moved to its unlocking position under the urging of the lock link biasing member  34 . 
     During use of the vehicle latch  10  the situation illustrated in  FIG. 4   a  can occur when a first person (eg. the vehicle owner) presses an ‘unlock’ button on a key fob, and during this action, an impatient passenger eager to enter the vehicle prematurely lifts the outside door handle (shown at  53  in  FIG. 1 ), thereby actuating the outside door release lever  16  before the lock link  18  has been moved to its unlocking position. As a result, while the passenger keeps the outside door handle  53  ( FIG. 1 ) lifted, the lock link  18  ( FIG. 4   a ) is prevented from moving from the locking position to the unlocking position, but when the passenger releases the door handle  53  ( FIG. 1 ), the outside door release lever  16  moves back to its home position and the lock link  18  can then move to its unlocking position under the urging of the lock link biasing member  34 . By contrast, in some prior art vehicular latches (not shown), there is no slot connection between the lock link and whatever drives the lock link, and so, in such a situation where an impatient passenger lifts the door handle  53  ( FIG. 1 ) before the vehicle owner presses the unlock button, the lock link and any members that drive the lock link are all prevented from moving to their respective unlocking positions. As a result, when the door handle  53  ( FIG. 1 ) is finally released in such prior art latches, there is nothing urging the lock link to its unlocking position, and so the vehicle owner must then press the ‘unlock’ button a second time in order for the unlocking action to be carried out. 
     This structure (ie. the slot  38  and pin  36  connection between the lock link  18  and the lock link driver  20 , and the lock link biasing member  34  for biasing the lock link  18  to its unlocking position) together make up the ‘impatient passenger’ structure  26 . 
     The lock link driver  20  ( FIGS. 5   a  and  5   b ) includes a manual rotation feature  54  (which in the embodiment shown is a tool-receiving feature  54 ) that permits it to be rotated between its locking position ( FIG. 5   a ) and its unlocking position ( FIG. 5   b ), thereby permitting the vehicle door  11  ( FIG. 5   b ) to be locked (and unlocked if desired) in the event that the power lock actuator  22  is unusable. For example in the event of a failure of some element that controls operation of the power lock actuator  22  (eg. a disconnection between the motor  42  and its power source, or a failure of the motor  42 ), the vehicle owner cannot use the power lock actuator  22  to lock or unlock the latch  10 . In such a situation, an appropriate tool could be inserted into the tool-receiving feature  54  ( FIG. 5   a ) and could be used to manually rotate the lock link driver  20  to its locking position, which in turn drives the lock link  18  ( FIG. 2 ) to its locking position. The lock link driver  20  with the manual rotation feature  54  thus constitutes the emergency lock actuator  24 . This permits the vehicle owner to lock the vehicle as needed until he or she can have the vehicle repaired. 
     In the embodiment shown, driving the lock link driver  20  manually by means of the emergency lock actuator  24  causes the sector gear member  46  ( FIG. 2 ) to rotate, which in turn causes the worm gear  44  to rotate. It will be understood that these components (ie. the sector gear member  46 , the worm gear  44  and the electric motor  42 ) are configured to accommodate being back-driven by the lock link driver  24 . For example, the shape and pitch of the thread on the worm gear  44  may be selected to permit the worm gear  44  to be back-driven by the sector gear member  46 . 
     As can be seen in  FIGS. 5   a  and  5   b , the emergency lock actuator  24  is accessible from the exterior of the vehicle door  11 . For greater clarity, the ‘exterior of the vehicle door’ refers to any exterior portion of the vehicle door, such as the face of the door that faces the exterior of the vehicle, the face of the door that faces the interior of the vehicle, and the edge face of the door (shown in  FIG. 1  at  55 ). In the embodiment shown in the figures, the emergency lock actuator  24  is accessible from the edge face  55  of the door  11  proximate the fishmouth of the vehicle latch  10 , which is shown at  56 . As a result, the emergency lock actuator  24  is inaccessible from outside the vehicle when the door  11  is closed, thereby preventing a would-be thief from using it to gain entry into the vehicle. It is inaccessible from inside the vehicle when the door  11  is closed. As a result, a would-be thief cannot access it using tools slipped in from above the window seal from the outside of the vehicle. Such tools have been used in the past by thieves to unlock the door by actuating a lock knob located on the door sill or in other parts of the inside facing door panel. 
     The lock link driver  20  with the integral manual rotation feature  54  that is accessible from the exterior of the door  11  (eg. from the door edge as shown in  FIGS. 5   a  and  5   b ), and with the integral slot  38  ( FIG. 2 ), combined with the lock link biasing spring  34  constitute a simple, inexpensive means for providing emergency lock actuation and for providing an ‘impatient passenger’ feature. 
     Referring to  FIG. 2 , the vehicle door  11  may further include a key cylinder  58  that permits the latch  10  to be unlocked manually (ie. by means of a mechanical connection between the key cylinder  58  and the lock link  18 , via engagement of surface  59   a  on key cylinder  58  with surface  59   b  on lock link driver  20  wherein rotation of the key cylinder  58  rotates the lock link driver  20  and therefore the lock link  18  between the locking and unlocking positions) from the exterior of the vehicle by a person with a key. This permits the vehicle owner to unlock or lock the latch  10  on a closed door  11  from outside the vehicle when the power lock actuator  22  is not usable. On a vehicle, which typically has two or more doors, at least one of the doors includes a key cylinder  58  and the remaining doors do not have a key cylinder. In this way, all the doors can be locked (by the emergency lock actuator  24  on doors so equipped, and by the key cylinder  58  on doors so equipped). Entry back into the vehicle is provided by means of any doors with the key cylinder  58 . Once inside the vehicle, the door latches on the other doors may be configured so that the inside door handle can be pulled on them to automatically unlock and open them. 
     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.