Abstract:
With a lock for a front hood of a motor vehicle, a locking pawl engages about a rotary latch. This engagement creates a positive connection of the locking pawl to the rotary latch perpendicularly to their intended movement directions. This prevents that during a crash of the motor vehicle the locking pawl is separated from the rotary latch and the lock therefore unlocked.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National-Stage entry under 35 U.S.C. §371 based on International Application No. PCT/EP2008/005345, filed Jul. 1, 2008, which was published under PCT Article 21(2) and which claims priority to German Application No. 102008023490.7, filed May 14, 2008, which are all hereby incorporated in their entirety by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a lock of a hood of a motor vehicle with a lock case, with a rotary latch mounted in the lock case for the optional holding or releasing of a closing part and with a pivotably mounted locking pawl for supporting the rotary latch in the position of the rotary latch holding the closing part. 
       BACKGROUND 
       [0003]    Locks are frequently employed in modern motor vehicles for locking front hoods opening in driving direction and are known from practice. The rotary latch of the known lock is preloaded into the release position of the closing part. If, starting out from the position of the rotary latch holding the closing part, the locking pawl is removed from the rotary latch the rotary latch moves into the position releasing the closing part. After this the front hood can be opened. 
         [0004]    Disadvantageous with the known lock, however, is that in the event of a crash of the motor vehicle the locking pawl can be separated from the rotary latch. This subsequently leads to an undesirable opening of the front hood. The separation of the locking pawl from the rotary latch mostly occurs through a deformation of the lock case, as a result of which the components can for instance be tilted against each other. In this case, the rotary latch is no longer reliably supported by the locking pawl. 
         [0005]    One could think about stiffening or providing the locking case with guides for the rotary latch and the locking pawl so as to prevent a separation of the rotary latch from the locking pawl during a crash of the motor vehicle. Such stiffeners or guides however lead to an increase of the constructional expenditure of the lock. Furthermore, the lock case can still be deformed in the event of a particularly severe crash and separation of the rotary latch from the locking pawl can nevertheless occur because of this. 
         [0006]    In view of the foregoing, it is desirable to develop a lock of the type mentioned at the outset so that it can be particularly easily produced and makes possible a high level of protection against separation of the locking pawl from the rotary latch. In addition, other desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background. 
       SUMMARY 
       [0007]    According to an embodiment of the invention, the position of the rotary latch holding the closing part the locking pawl and the rotary latch are positively connected to each other towards both sides perpendicularly to their movement direction. 
         [0008]    Through this configuration the connection of the component of the lock is affected through the positive connection of the locking pawl to the rotary latch. Since this positive connection occurs towards both sides perpendicularly to their intended movement directions, the release of the positive connection can only be effected through movement of the locking pawl in its intended movement direction. Releasing of the positive connection through tilting or perpendicular displacement of the locking pawl to the rotary latch as occurs during a crash of the motor vehicle is avoided thanks to the invention. Since the positive connection of the rotary latch with the locking pawl in the simplest case can be effected through suitable shaping of the components, the lock according to the invention only requires a particularly small number of components and can be produced particularly cost-effectively. 
         [0009]    The positive connection of the rotary latch with the locking pawl according to an advantageous further embodiment of the invention is particularly simple in terms of design if in the position of the rotary latch holding the closing part the locking pawl engages about a leg of the rotary latch. Preferentially, the rotary latch is designed as so-called fork latch with two legs, wherein the closing part is held between the legs. 
         [0010]    The constructional expenditure for the engaging configuration of the locking pawl according to another embodiment of the invention can be kept particularly low if in the position of the rotary latch holding the closing part the locking pawl comprises an arm and a folded portion, wherein the leg of the rotary latch is arranged between the arm and the folded portion. In a lateral view the arm and the folded portion thus form a U-shape between which the one leg of the rotary latch is arranged. Preferentially, arm and folded portion are produced unitarily of a sheet metal part. 
         [0011]    According to another embodiment of the invention the assembly of the hood lock is particularly simple if the rotary latch and the locking pawl are pivotably mounted on bearing mandrels unilaterally mounted in the lock case. 
         [0012]    To further simply the assembly of the lock it contributes if the lock case has a base with the bearing mandrels and lateral webs standing away from the base and if fastening flanges lead away from the free ends of the lateral webs. Furthermore, the lock mounted in the motor vehicle is particularly sturdy as a result. 
         [0013]    The lock according to an embodiment of the invention is configured particularly compact if the rotary latch and the locking pawl are each preloaded in their intended position by a leg spring. 
         [0014]    The folded portion can be arranged in almost any position of the locking pawl. The locking pawl however is particularly simple in design if the folded portion is unitarily produced with a hook and if the leg spring for preloading the locking pawl supports itself on the hook. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
           [0016]      FIG. 1  is a lock according to an embodiment of the invention; 
           [0017]      FIG. 2  is a view from Position II on to the lock according to the embodiment of the invention from  FIG. 1 ; 
           [0018]      FIG. 3  is an enlarged a perspective representation of a locking pawl of the lock according to the embodiment of the invention from  FIG. 1 ; and 
           [0019]      FIG. 4  is a further embodiment of the lock according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description. 
         [0021]      FIG. 1  shows a lock  1  of a front hood that is not shown of a motor vehicle with a lock case  2 . In the lock case  2  a rotary latch  3  is pivotably mounted and engages about a closing part  4  shown schematically. The closing part  4  is thus positively held in the lock  1  by the rotary latch  3 . This characterizes the locking position of the lock  1 . The lock case  2  as a rule is fastened to a body part of the motor vehicle, while the closing part  4  is arranged on the front hood. 
         [0022]    The rotary latch  3  is held in the shown locking pawl  5  likewise pivotably mounted in the lock case  2 . The locking pawl  5  and the rotary latch  3  are each mounted on bearing mandrels  6 ,  7  fastened in the lock case  2  and are preloaded against each other by leg springs  8 ,  9 . For supporting on the locking pawl  5  the rotary latch  3  comprises a leg  10 . A second leg  11  engages about the locking part  4  in the locking position shown. If the locking pawl  5  is moved clockwise out of the movement region of the rotary latch  3  through a pivot movement, the rotary latch  3  is pivoted through the force of the leg spring  9  and releases the closing part  4 . Thus the closing part  4  can be removed from the lock case  2 . 
         [0023]    The locking pawl  5  comprises an arm  12  with which it is passed through under the one leg  10  of the rotary latch  3 . At the free end of the arm  12  folded portions  13  are routed back as far as over the arm  12 . The one leg  10  is arranged between the arm  12  and the folded portion  13  and thus positively connected to the locking pawl  5  towards both sides perpendicularly to the movement direction of the rotary latch  3 . Thus it is prevented that through a movement of the locking pawl  5  or the rotary latch  3  the components are separated from each other perpendicularly to the drawing plane and thus the movement of the rotary latch  3  is released. 
         [0024]    In a view on to the lock  1  from Position II from  FIG. 1 ,  FIG. 2  shows that the lock case  2  comprises a base  14  with lateral webs  15 ,  16  standing away. At the free ends of the lateral webs  15 ,  16  fastening flanges  17 ,  18  stand away. Thus the lock case  2  can be easily fastened to the body part of the motor vehicle. The bearing mandrels  6 ,  7  for mounting the rotary latch  3  and the locking pawl  5  are fastened to the base  14 . To simplify the drawing, the closing part  4  from  FIG. 1  is not shown. 
         [0025]      FIG. 3  shows enlarged the locking pawl  5  of the lock  1  from  FIG. 1  in a perspective representation. There it can be seen that the locking pawl  5  has a bearing eye  19  for fitting on to the bearing mandrel  7  of the lock case  2 . On the arm  12  a stop  20  for the rotary latch  3  and the folded portion  13  engaging about a leg  10  of the rotary latch  3  are arranged. Furthermore, the locking pawl  5  has a hook  21  for supporting the leg spring  9  and a triggering arm  22 . The locking pawl  5  is formed of a flat sheet metal part. 
         [0026]      FIG. 4  shows a further embodiment of the lock according to the invention, which differs from that from  FIG. 1  only in that a folded portion  23  is arranged on a locking pawl  24  on a hook  25 . A leg spring  26  supports itself on the hook  25 . As with the embodiment according to  FIG. 1 , a leg  27  of a rotary latch  28  is arranged between the folded portion  23  and an arm  29  of the locking pawl  24 . Otherwise the construction of this embodiment corresponds to the embodiment described in the  FIG. 1  to  FIG. 3 . 
         [0027]    While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.