Abstract:
The invention relates to a lock for a motor vehicle with a locking mechanism including a catch and a pawl. The object of the invention is to simplify the locking of a lock of the type mentioned above. To achieve the object of the invention, a catch of the claimed lock comprises a stop projecting upwards, e.g., in the form of a pin extending from the catch. Furthermore, a bracket is provided, which can be moved against the stop by means of a motor such that the catch is moved in this way from the first position and into the primary position. It is thus possible to move from the first position to the primary position in a motorized manner, which makes it easier to close the vehicle door.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a National Stage Application of International Patent Application No. PCT/DE2010/000657, with an international filing date of Jun. 11, 2010, which is based on German Patent Application No. 10 2009 026 921.5, filed Jun. 12, 2009. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a lock for a motor vehicle with a locking mechanism comprising a catch and a pawl with which the catch can be locked in a closed position. The invention relates, in particular, to a lock with a pawl for engaging in a primary position (hereafter referred to as the “primary-position pawl”), and a pawl for engaging in a first position (hereafter referred to as the “first-position pawl”) and a blocking lever for engaging said primary-position pawl. Such a lock is known from DE 10 2007 003 948 A1. 
     2. Brief Description of the Related Art 
     The catch of a motor vehicle lock has a fork-shaped inlet slot into which a locking pin attached to a vehicle door or hatch enters when the vehicle door or hatch is closed. The locking pin then rotates the catch from an open position to a closed position. When the catch reaches the closed position, the locking pin can no longer leave the inlet slot of the catch. In the closed position, the pawl locks the catch such that the catch cannot be rotated back into the open position. 
     Frequently, a motor vehicle lock has two closed positions, which are taken up consecutively during the closing process of the catch, namely the so-called first position and the so-called primary position. 
     To prevent the pawl from leaving its locked position unexpectedly, a blocking lever can be provided to block such movement when the catch is locked. Such a blocking lever is necessary for the primary-position pawl of the lock described in DE 10 2007 003 948 A1 because the catch and the primary-position pawl are constructed such that the pawl assuming the primary position pushes the primary-position pawl out of the latched position. 
     The rotatably arranged blocking lever, known from DE 10 2007 003 948 A1, is biased by a spring. Because of this bias, when the catch is not in the primary position, the blocking lever exerts pressure on the primary-position pawl in the direction toward the catch. This pressure is responsible for ensuring that the primary-position pawl is moved into its locked position when the catch reaches the primary position. The bias then further ensures that the blocking lever is ultimately moved into the blocking position so that the vehicle door or hatch closes completely. 
     To unlock the lock, the blocking lever is rotated, with the help of the first-position pawl, against the biasing force until the blocking lever sets free the primary-position pawl. The primary-position pawl is then pushed by the catch from the locked position or is stricken by a driver of the first-position pawl, and in this way is moved out of the locked position. Subsequently, the catch rotates into the open position from the primary position due to a commensurate bias. The locking pin can then move out of the inlet slot, and the attached vehicle door or hatch can be pushed ajar. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The object of the invention is to simplify the opening of a lock of the type mentioned above. 
     The object of the invention is achieved by providing a lock having the characteristics of the first claim. Advantageous embodiments are described in the dependent claims. 
     To achieve the object of the invention, the catch of the claimed lock comprises an upwardly projecting stop, which, for example, takes the form of a pin rising above the catch. Furthermore, a bracket is provided, which can be moved against the stop by means of a motor such that the catch is moved in this way from the first position and into the primary position. It is thus possible, to move from the first position to the primary position in a motorized manner, which makes it easier to close the vehicle door. The stop acts at the same time as a stop for the pawl. In this way the number of required components is also kept to a minimum. 
     In one embodiment of the invention, the stop also serves as a stop for the first-position pawl, which thereby locks the catch in this position. In this embodiment, there is also no need for an additional stop for locking the catch using the first-position pawl. 
     In one embodiment of the invention, the bracket is disposed above the first-position pawl seen from the wall of the housing on which the catch is pivotally mounted. In this way, it is structurally possible to use a pin having a thin diameter, both as a stop for the bracket as well as a stop for the first-position pawl. 
     In one embodiment of the invention, provided is a guide that guides the locking pin relative to the position of the first-position pawl. On the one hand, the bracket is drawn hereby against the stop. On the other hand, it is possible by the movement of the first-position pawl to redirect the movement of the bracket such that the bracket is not moved against the stop. It is possible to prevent, for example during an emergency, the automatic closing of the door from the first position to the primary position through the movement of the first-position pawl. When the first-position pawl is moved, the locking of the catch by the first-position pawl is also unlocked, simultaneously, and the door or hatch can be opened immediately. Such an emergency can arise, in particular, when a finger is jammed in a door or hatch. 
     In one embodiment of the invention, the bracket is first guided on an essentially straight line until the bracket has reached the stop. Then, the guide runs in an arcuate configuration such that the bracket can follow the rotational movement of the catch. 
     In one embodiment of the invention, the catch is connected to microswitches that read the position of the first-position pawl and the primary-position pawl. In this way, the motor-driven movement of the bracket against the stop may be controlled in order to move the catch from the first position to the primary position. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1 . shows a closed position of a lock with the first-position pawl shown as transparent; 
         FIG. 2  shows the closed position of the lock of  FIG. 1 ; 
         FIG. 3  shows the lock of  FIG. 1  with a bracket for moving the catch; and 
         FIG. 4  shows the lock of  FIG. 1  with the microswitches. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An exemplary embodiment of the invention shown in the figures will be explained hereinbelow in more detail. Advantages of further embodiments of the invention will be illustrated with reference to the exemplary embodiment. 
       FIG. 1  shows a plan view of a housing wall  1  of a vehicle lock. The housing wall  1  is provided with an inlet slot  2 , into which a locking pin  3  of a vehicle door or vehicle hatch enters when the corresponding vehicle door or vehicle hatch is closed. The catch  4  is rotatably mounted on the housing wall  1  and can be rotated about its mounting axis  5 .  FIG. 1  shows the primary position, in which the locking pin  3  located in the inlet slot  2  in the wall housing is enclosed by the inlet slot of the catch such that the locking pin  3  can no longer be moved out of the inlet slot  2  in the wall housing. The corresponding door or hatch of the vehicle is thus closed. It is obvious that the primary position is shown here because in this figure a turning back of the catch according to the arrow direction  22  toward the open position is blocked by the primary-position pawl  6 . The primary-position pawl  6  is also mounted on the housing wall  1  and is rotatable about its mounting axis  7 . The catch is biased in the direction toward the open position, preferably by a spring (not shown). Because of this tension, the catch presses diagonally against a stop of the primary-position pawl. Pressing along the diagonal direction pushes the primary-position pawl out of the locked position. 
     If the catch is not biased by a spring, when said vehicle door or hatch is opened, at least the locking pin  3  causes the rotation of the catch  4  toward the open position as indicated by the arrow  22 . The associated torque then pushes the primary-position pawl  6  out of the locked position. However, this is prevented in the primary position by the blocking lever  8 , as shown, when the vehicle door or hatch is closed. The blocking lever  8  is also mounted on the housing wall  1  and can be rotated about its mounting axis  9 . On a lateral contour area of the blocking lever  8  is disposed an arm  10   b  of a spring  10 . The spring  10  is pre-tensioned such that the arm  10   b  of the spring  10  presses the blocking lever in the direction toward the shown blocking position (in the direction of arrow  11 ). The rotational movement of the blocking lever, caused thereby, is limited, as shown, by the stop  12 , which is attached to the housing wall  1  in the form of a protruding pin. The stop  12  causes the blocking lever to be oriented always very precisely in the same blocking position, which is particularly important for the proper functioning of the blocking lever. To allow for a low profile, the spring  10  is arranged predominantly laterally next to the blocking lever  8  as well as next to the first-position pawl. Only one arm  10   a  of the spring  10  extends beyond the blocking lever  8 . 
     Above the primary-position pawl  6  is arranged a first-position pawl. The first-position pawl is also pivotally mounted on the shaft  7  and can, therefore, also be rotated about the axis  7 . The outline  13  of the first-position pawl is indicated with dots. The first-position pawl  13  comprises a pin  14 , which extends down from the first-position pawl in the direction toward the housing wall  1 . At this pin  14 , which is attached to the first-position pawl, is disposed the other arm  10   a  of the spring  10 . The other arm of the spring  10  pushes in the direction toward the pin  14  along the arrow  15 . In the primary position, the pin  14  also lies closely against the lateral contour area of the blocking lever  8 . When the first-position pawl  13  is turned in the direction of the arrow  16 , the pin  14  causes the blocking lever  8  to be rotated out of the blocking position. The spring arm  10   a  can follow the movement of the stop or the pin  14  such that the rotation of the first-position pawl  13  is not hampered by an opposing force, which would otherwise originate from the spring arm  10   b . This facilitates the rotation of the blocking lever  8  by the first-position pawl  13  out of the blocking position. When the blocking lever  8  is moved from the blocking position, the primary-position pawl  6  is pushed away by the catch from its shown locked position. Additionally or alternatively, the lateral contour area of the first-position pawl  13  strikes a protruding pin  17 , which serves as a stop, and which is attached to the primary-position pawl  6 . This has the consequence that the primary-position pawl  6  is rotated out of the shown locked position and releases the catch. The catch then pivots in the direction of the arrow  22  toward the open position and finally sets free the locking pin  3 . The corresponding door or gate can then be opened. 
     The first-position pawl  13  can also lock the catch  4  when a protruding pin  18  of the catch  2  strikes against the lateral contour area  19  of the first-position pawl  13  and thus prevents the rotation of the pawl toward the open position in accordance with the arrow  22 . The first-position pawl  13  is preferably biased by a spring (not shown) in the direction toward its locked position. A protruding pin  20 , which serves as a stop and is secured to the housing wall  1 , prevents further rotation of the first-position pawl beyond its locked position. 
     The primary-position pawl  6  is preferably not directly biased by a spring. The primary-position pawl  6  is instead appropriately rotated alone by other components, and especially particularly by the rotation of the catch  4 , the first-position pawl  13  and/or the blocking lever  8 , e.g., by the rotation of the blocking lever  8  into the locked position (primary position). The corresponding rotation of the blocking lever is caused by the supplied tension of the spring  10 . 
     In order to move the primary-position pawl with the help of the blocking lever suitably into the locked position, hook-like endings  6   b  and  8   a  have been found to be particularly suitable. The head of the hook  6   b  of the primary-position pawl acts as a stop for the catch. The tip of the hook  6   b  is blocked in the primary position by the head of the hook  8   a . If the blocking lever  8  is rotated out of the blocking position, then the two hooks  6   b  and  8   a  interlock. The top end  6   b  ultimately pushes the hook  8   a  so far outward that the lever arm  8   b  of the pin  14  is lifted, whereby the bias of spring  10  is increased (see also  FIG. 3 ). The rotation of the first-position pawl  13  is further facilitated because the first-position pawl  13  no longer exerts a moment of inertia on the blocking lever  8 . The movement of the tip  6   b  or the primary-position pawl  6 , which is responsible for moving the arm  8   b  away from the pin  14 , is then caused by the catch, which rotates toward the open position, wherein the lateral contour area  4   a  presses against the then-adjacent lateral contour area of the hook  6   b . As shown, the end portion  4   b  of the contour area  4   a  is angled or bent outwards (as seen from the catch) in order to rotate the primary-position pawl, and thereby to rotate the hook  6   b , particularly toward the outside along the arrow  16 . As a result of this rotation, the lever arm  8   b  is moved particularly far away from the stop  14 , and a desirable bias is then provided by the spring  10 . Advantageously, the tip of the hook  6   b  is longer than the tip of the hook  8   a  in order to provide a particularly large tension of the spring  10 . Because the hook  8   a  does not have to achieve such an effect, the hook  8   a  is relatively short. All of this ensures a particularly reliable operation. 
     If the catch is rotated from the open position toward the closed position up to the first position, the first-position pawl then snaps into its locked position, wherein the first-position pawl is then rotated opposite to the direction of the arrow  16  until a further rotation is limited by the stop  20 , as shown in  FIG. 1 . In this first position, the corresponding lateral contour section of the hook  6   b  still lies against the lateral contour area  4   a . This blocks the rotation of the blocking lever  8  such that the arm  8   b  is moved in the direction of the arrow  11 . The bias of the spring  10  is then further increased in a desired manner. When the lateral contour portion  4   a , which extends from the corner point  4   b  to the corner point  4   c , ultimately sets free the primary-position pawl  6 , a high biasing force is provided in order to reliably move the primary-position pawl into the locked position when the corresponding vehicle door or hatch is closed. 
     To rotate the first-position pawl out of its locked position, in order to unlock the lock, the first-position pawl is stricken at the grip area  21  and rotated. The striking and rotating of the first-position pawl  13  can be done manually or with the help of a motor. Since the first-position pawl can also be rotated backwards by a motor, a spring that biases the first-position pawl in the locked position is not mandatory. For performance and safety reasons is, however, the provision of such a spring beneficial. 
     The previously described characteristics of the exemplary embodiment can be applied individually or in combination to the inventive lock. 
       FIG. 2  shows the lock of  FIG. 1 . However, the first-position pawl  13  is not shown as transparent in this figure. Therefore, the first-position pawl  13  partially covers inter alia the primary-position pawl  6 .  FIG. 2  illustrates that a protruding pin  30 , projecting upward as seen from the housing wall  1 , is disposed on the first-position pawl. This pin is made of metal and a plastic sleeve is disposed around it. The pin  30  with the sleeve  31  carries a bracket not shown in  FIG. 2 . The plastic reduces friction and associated noise when the bracket is moved. 
       FIG. 3 , as compared to  FIG. 2 , additionally shows the bracket  32 , which is located above the first-position pawl  13 . The bracket is provided with a slot  33 , into which the projecting pin  30  of the first-position pawl reaches. The bracket  32  is steered and guided by means of the slot  33  and the pin  30 . The bracket can be moved back and forth between an initial position and an end position, as shown in  FIG. 3 . The end position is reached when the catch  4  is turned from the first position to the primary position through the movement of the bracket  32  from the initial position to the end position. 
     To move the bracket by means of a motor, the bracket comprises a pin  34  that projects upward. The pin  34  extends into a hole of a lever that is disposed above it. The lever can in turn be rotated about an axis. While the lever is rotated about its axis by means of a motor, the bracket is moved between the initial position and the end position. However, when the first-position pawl is rotated in the direction of the arrow  16  by actuating of a door handle connected thereto, the bracket pivots upward in the direction of the arrow  35 . In this way, the bracket loses contact with the pin  18  of the catch, which pin serves as a stop. A forward movement of the bracket toward the end position, then, no longer results in the rotation of the catch  4  toward the direction of the primary position. Instead, the catch is released and can rotate back into the open position. 
     The slot  33  extends as shown partly in a curved manner such that it and the corresponding end bracket  36  (which is adjacent to the stop  18 ) eventually follow the rotational movement of the catch and the rotation of the stop  18  associated therewith. 
     If the catch is locked in the first position by the first-position pawl  13 , wherein the pin  18  pushes against the lateral contour portion  19  of the first-position pawl and in this way prevents the rotation of the catch toward the open position, the aforementioned bracket end  36  initially has, advantageously, a small distance to the pin  18 , e.g., 1 to 3 mm, so as not to impair the locking of the catch. When the bracket is subsequently driven from the initial position by means of a motor, the bracket reaches the stop  18 , then presses the stop  18  toward the primary position while the first-position pawl is not moved. The first-position pawl will generally not move at this time because it is biased, presses against the stop  20 , and remains in this position. 
       FIG. 4 , as compared with  FIG. 3 , additionally shows the lever  37 , which is mounted rotatably about the axis  38 . The lever  37  is rotated counterclockwise about its rotational axis  38  by pulling of the cable  39  in the direction of the arrow and, thereby, the associated bracket is rotated, as described above, from its initial position to its final position. The pin  34 , which reaches into a corresponding hole of the lever  37 , projects also advantageously out of this hole upwards, and is then disposed between two stops (not shown) in order to appropriately limit the movement of the bracket and the movement of the lever. The stops are designed to limit excessive forces that act on parts of the locking mechanism, which could otherwise damage it. 
     The cable  39  is attached to the end of the longer lever arm of the lever  37 , as seen from the axis of rotation  38 , as compared to the other shorter lever arm with a hole into which at least the pin  34  extends. In this way, the motor force that pulls on the cable  39  is amplified according to the lever rule. It is, therefore, sufficient to use a relatively small motor force to rotate the catch from the first position to the primary position. The cable  39  is hooked into a designated hook of the lever  37 . 
     The lever  37  is advantageously biased in the direction toward the starting position such that the lever  37 , and thereby also the bracket  35 , can pivot on their own back to their initial positions, even when the motor drive should fail. Therefore, a malfunction of the motor does not result in a malfunction of the lock. 
     As shown in  FIG. 4 , in one embodiment of the invention, a microswitch  40  is advantageously located adjacent to the corresponding lateral contour areas of the first-position pawl and/or the primary-position pawl, depending on the positions of the affected pawls. The positions of each pawl can then be read by the microswitch. If it is determined by means of the microswitch, for example, that the first-position pawl has reached the stop  20  but that the primary-position pawl is not yet present in its locked position, then the motor is set in motion to pull on the cable  39 . The drive motor is stopped as soon as another microswitch determines that the primary-position pawl has snapped into its locked position. 
     Shoe-shaped lever arms, as shown in the figures, are useful for determining at any time the position of the corresponding pawls, with the help of microswitches and with minimal use of materials. These lever arms are useful for controlling the movement of the parts of the lock. 
     If the bias of the lever  37  is chosen to be appropriately strong, in a certain embodiment of the invention, the spring force turns the lever  37  back into its initial position after the motor drive has stopped.