Patent Publication Number: US-2006005591-A1

Title: Electrically-releasable lock

Description:
REFERENCE TO RELATED APPLICATIONS  
      This application claims priority to French Patent Application 04 06 638 filed on Jun. 18, 2004.  
     BACKGROUND OF THE INVENTION  
      The present invention relates generally to an electrically-releasable lock.  
      An electrically-releasable lock is electrically operated, and the operational power supply comes, for example, from the vehicle&#39;s battery. When a power failure occurs, for example as a result of the vehicle being involved in an accident, an emergency mechanical method of operating the lock may be provided. For example, discharge from a capacitor may momentarily supply power to a system inside the lock, allowing it to be opened mechanically so that the passengers can exit the vehicle. The problem which arises is that the lock&#39;s emergency power supply is then insufficient to reactivate the functions of the electrical lock and keep the door shut if the occupants want to abandon the vehicle.  
      A need therefore exists for an electrical lock which can be reactivated after an emergency operation.  
     SUMMARY OF THE INVENTION  
      The present invention provides an electrically-releasable lock having emergency mechanical linkages which are brought into action in the event of a failure in the lock&#39;s power supply. The lock also has an actuator for disengaging the emergency mechanical linkages.  
      In one embodiment, the emergency mechanical linkages are automatically engaged in the event of a failure in the lock&#39;s power supply. In another embodiment, the actuator is manually activated. In another embodiment, the actuator rotates. In yet another embodiment, the disengagement of the mechanical linkages cannot be reversed by the actuator. In another embodiment, the actuator has a spring arm for returning the actuator to an initial position.  
      The invention also provides a vehicle door including the lock as described previously, and the disengaging actuator is on the edge of the door.  
      The invention also provides a method for securing an electrical lock whose power supply has failed. The lock includes emergency mechanical linkages and an actuator for disengaging the mechanical linkages. The method includes an actuator-activation stage that changes the lock from an operating state in which the emergency mechanical linkages are engaged to a secured state in which the mechanical linkages are disengaged.  
      In one embodiment, the mechanical linkages automatically engage when the power fails. In another embodiment, the actuator is activated manually.  
      Other characteristics and advantages of the invention will become apparent when reading the following detailed description of embodiments thereof, given by way of example only and with reference to the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of an electrical lock in normal electric operation;  
       FIG. 2  is a perspective view of the electrical lock in emergency mechanical operation; and  
       FIG. 3  is a state diagram for the electrical lock. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      The invention provides an electrically opening lock including emergency mechanical linkages which are engaged in the event of a power failure. The lock also includes an actuator for disengaging the emergency mechanical linkages. The lock allows the mechanical linkages which have been engaged to be re-disengaged to enable the lock&#39;s mechanical operation in place of its defective electrical operation in the event of a power failure. This is advantageous if the user of the vehicle wants to abandon the vehicle safely.  
       FIG. 1  shows a perspective view of an electrical lock  10  in normal electric operation, i.e., an electrically-releasable lock. Only the cam-shaped release member  12  which cooperates with a claw of the latch mechanism is shown. The electrical lock  10  also includes emergency mechanical linkages which are engaged in an emergency. Of the emergency mechanical linkages, the emergency lever  14  is illustrated. In  FIG. 1 , the mechanical linkages are not engaged, i.e., the lower part of the lever  14  does not come into contact with cam-shaped release member  12 .  
      The emergency mechanical linkages are preferably automatically engaged, which avoids the user having to engage the linkages himself. This makes it easier to exit the vehicle. The emergency mechanical linkages, in this case the lever  14 , are engaged by an emergency power supply, which is not illustrated. If a failure in the power supply occurs while the vehicle is moving and the electrical lock  10  cannot be activated, the emergency power supply still allows the emergency mechanical linkages to be engaged. When the mechanical linkages are engaged, the electrical lock  10  can be mechanically activated, and the passengers can exit the vehicle. However, the emergency power supply replaces the normal power supply only for a short time. For example, the emergency power supply only allows the mechanical linkages to engage once to limit the cost of the emergency power supply.  
      The power supply is, for example, a capacitor whose discharge makes up for the defective electrical supply of the electrical lock  10 . Once discharged, the capacitor can then no longer supply power to the electrical lock  10 . In  FIG. 1 , the lever  14  is rotatably mounted around a shaft  16 , and the rotation of the lever  14  around the shaft  16  allows the mechanical linkages to engage.  
      The electrical lock  10  includes an emergency motor  20  activated by the emergency power supply. The emergency motor  20  drives the lever  14  to engage the mechanical linkages. The emergency motor  20  is connected to the lever  14  by a screw  22  and a nut  18 . The nut  18  is connected to a pin  26  of the lever  14 , and the pin  26  rotates with respect to the nut  18 . Moreover, the electrical lock  10  includes a switch  24  that turns on to indicate that the emergency mechanical position is activated to diagnose proper operation of the emergency system. In  FIG. 1 , the switch  24  is not turned on. The switch  24  can be turned on by the nut  18 . The nut  18  has a surface  28  which comes into contact with the switch  24 . One face of the surface  28  can be bevelled to facilitate contact between the nut  18  and the switch  24 .  
      The operation of engaging the mechanical linkages will now be described and shown in  FIG. 2 .  FIG. 2  shows a perspective view of the electrical lock  10  in emergency operation. The lever  14  is engaged in the sense that it can intercept the rotational movement of cam-shaped release member  12  and thus come into contact with it. Actuation of a door handle mechanically operates the latch by means of the lever  14  and the cam-shaped release member  12 .  
      To ensure that the mechanical linkages engage, the emergency motor  20  is activated by the emergency power supply, preferably automatically, as soon as a power failure occurs. The emergency motor  20  rotates the screw  22 , which allows the nut  18  to move. The nut  18  is prevented from rotating when the screw  22  is moved by the pin  26  of the lever  14 . Thus, the nut  18  is moved in translation along the screw  22  towards the emergency motor  20 . The translation of the nut  18  allows the switch  24  to be turned on by means of the surface  28 . The switch  24  turning on indicates that the mechanical linkages are in the engaged state during stages that diagnose proper operation of the emergency system. The translation of the nut  18  also causes the lever  14  to rotate about its axis by means of the pin  26 . On completing its rotation, the lever  14  reaches the engaged position, and a pusher  30  at the lower end of the lever  14  comes into contact with the cam-shaped release member  12  when the release lever  12  rotates during mechanical release. In this engaged position of the lever  14 , the electrical lock  10  is in emergency operation when it can be mechanically activated to open without limitation.  
      The electrical lock  10  also includes a disengaging actuator  32 , shown in  FIGS. 1 and 2 . The actuator  32  allows the mechanical linkages to be re-disengaged so that the latch can no longer be mechanically activated to open. The actuator  32  ensures that the mechanical linkages disengage even when the electrical operation of the electrical lock  10  is defective or inactive as a result of a power failure. The actuator  32  returns the electrical lock  10  to the electrical operation position, and the electrical lock  10  then cannot be activated again until the power supply to the electrical lock  10  is restored. Thus, if the door is closed again while the mechanical linkages are disengaged, the latch is in the normal operation position but is inactive. It is therefore impossible to open the door, allowing the vehicle to be abandoned until a repair crew can restore the power.  
      The actuator  32  can be manually activated. The actuator  32  can therefore be activated when there is no power supply, particularly if the power supply is defective.  
      One embodiment of the actuator  32  is shown in the drawings. The actuator  32  can include an arm  34  for activating a shoulder  36 . In  FIG. 1 , the actuator  32  is in the off-position and does not contact the disengaged lever  14 . When the mechanical linkages are engaged as in  FIG. 2 , the lever  14  contacts the actuator  32 . Activating the actuator  32  allows the lever  14  to be returned to the position shown in  FIG. 1 .  
      In this embodiment, the actuator  32  can be rotated to disengage the lever  14 . To this end, the actuator  32  can be provided with a thumb wheel  38  connected to one end of the arm  34 . In the position in  FIG. 2 , rotation of the thumb wheel  38  moves the lever  14  by means of the shoulder  36 . The shoulder  36  can, for example, come into contact with the pin  26  by which the nut  18  rotates the lever  14 . Contact with the pin  26  by the lever  14  (made of plastic, for example) allows a 90° reverse motion in the example of construction envisioned. Since the thread profile of the screw  22  is reversible, the disengaging movement of the lever  14  allows the nut  18  and the emergency motor  20  to be moved in the opposite direction to the engaging direction of the mechanical linkages. The thumb wheel  38  can have an opening  40  into which a tool is inserted to rotate the thumb wheel  38 . The opening can be shaped such that the thumb wheel  38  can only be moved by a special tool.  
      The actuator  32  may, for example, be activated from the outside of the door to which the electrical lock  10  is fitted. When the user opens the door by mechanically actuating the door handle thanks to the engaged mechanical linkages, the user can then activate the actuator  32  to disengage the mechanical linkages and close the door securely. The actuator  32  is, for example, positioned so that the thumb wheel  38  is accessible on the edge of the door, which facilitates access to the actuator  32 .  
      The actuator  32  can only act upon the lever  14  to disengage the mechanical linkages. The disengagement of the mechanical linkages cannot be reversed by the actuator  32 , that is, it is not possible to engage the mechanical linkages using the actuator  32  (it is still possible to engage the mechanical linkages, however, via the emergency motor  20 ). This allows the vehicle to be secured in the sense that the actuator  32  cannot be picked by a thief to activate the latch mechanical and make it easy for him to enter the vehicle.  
      The actuator  32  can include a return element  42  for returning the actuator  32 . This allows the actuator  32  to be placed in contact with the lever  14  only when the lever  14  is engaged. Thus, the lever  14  can only be moved by the actuator  32  when the lever  14  is engaged. According to  FIGS. 1 and 2 , the return element  42  is a spring arm. One end  44  of the spring arm is connected to the actuator  32 , and the other end  46  of the spring arm is in contact with a stop which is not illustrated. In  FIGS. 1 and 2 , the actuator  32  is in the neutral position, and the return element  42  is not acted upon. When the lever  14  is engaged, from  FIG. 1  to  FIG. 2 , the lever  14  comes into contact with the actuator  32 . To disengage the lever  14 , the actuator  32  is activated by a rotation to the right, as shown in  FIG. 2 . As the end  46  is against its stop, the return element  42  is therefore subject to a bending movement when the actuator  32  rotates. When the lever  14  is disengaged again, the actuator  32  is released and elastically returned by the return element  42  to the neutral position shown in  FIG. 1 .  
       FIG. 3  shows a state diagram for the electrical lock  10 . This figure shows a method for securing the electrical lock  10 . Three states  50 ,  52 ,  54  of the electrical lock  10  are represented. The state  50  relates to the normal electrical operation of the electrical lock  10 , the latch being electrically active and the mechanical linkages being disengaged and inactive. The power supply to the electrical lock  10  is thus working. The state  52  relates to the emergency operation of the electrical lock  10 , the latch being electrically inactive and the mechanical linkages being engaged and active. The power supply to the electrical lock  10  has thus failed. The state  54  relates to the securing of the electrical lock  10 , the mechanical linkages being engaged and inactive. The power supply to the electrical lock  10  having failed, the electrical lock  10  is also electrically inactive.  
      The transition from the state  50  to the state  52  following the arrow  56  occurs when the power supply to the electrical lock  10  fails when the vehicle is moving, for example as the result of an accident. This transition can be achieved automatically. The transition from the state  52  to the state  54  following the arrow  58  occurs by activating the actuator  32 . In the state  54 , the electrical lock  10  is electrically inactive, and the mechanical linkages are disengaged. The latch can no longer be activated and is therefore secure. The transition following the arrow  58  is possible even when the lock is electrically inactive. The actuator  32  is preferably manually activated by the user. Moreover, the transition following the arrow  58  cannot be reversed using the actuator  32 . Finally, the transition from the state  54  to the state  50  following the arrow  60  is achieved by restoring the power supply to the electrical lock  10 . The power supply to the electrical lock  10  allows the electrical lock  10  to become active again, and to disengage the mechanical linkages.  
      Of course, the present invention is not limited to the embodiments described by way of example. Thus, the actuator is not limited to a rotational movement, but includes any other movement, such as translation, to disengage the mechanical linkages.  
      The foregoing description is only exemplary of the principles of the invention. Many modifications and variations are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than using the example embodiments which have been specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.