Abstract:
The invention relates to a door lock provided with a roller catch ( 11 ). When the door is closed an immobile locking part ( 10 ) moves into said roller catch ( 11 ), causing it to pivot from an open position into a preliminary or main latching position, the roller catch ( 11 ) being held by a latch. For greater user comfort and a more compact door lock the invention provides for the same drive motor ( 30 ) to be used as locking aid and as opening aid. A transmission element ( 35 ) which can be moved into two different positions is introduced into the gear assembly ( 31, 37 ). The drive energy generated by the drive motor ( 30 ) is transmitted in one position to the roller catch and in the other position to a second output track leading to the locking latch ( 20 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a door lock wherein the roller catch comprises in addition to the pre-catch also a main catch into which the pawl drops. Sometimes a gap remains when closing an open door because the pawl reaches only the pre-catch of the roller catch. This means that the roller catch remains in its pre-catch position. In order to be.able to close the gap, the auxiliary motor means are provided which engage the roller catch. They have the task to further move the roller catch into its final position in which the pawl drops into the main catch. In the following, this final position will be referred to as “main catch position”. The door gap is now closed. 
     2. Description of the Related Art 
     In a known door lock (DE 195 33 196 A1) two drive motors cooperate via two gears with a pivotable carousel support on which the pawl is positioned. One motor serves as a closing aid and the other motor as an opening aid. During closing, the pawl is pushed away by a pre-catch interruption lever until, by means of the locking part being inserted, the roller catch has reached its final main catch position relative to the pawl and the pawl drops into the main catch of the roller catch. Only thereafter, the drive motor is started and pivots the carousel support with the pawl so that the pawl rotates the roller catch past the main catch position into its rotational end position. In this case, a pawl that is entrained by the gear is provided, and the roller catch, after the pawl has dropped into its main catch, is still moved farther. An interruption of the drive motor is not provided and thus also does not result in a release of the transmission chain between the motor and the roller catch. 
     The known door lock requires a lot of space. During closing of the aforementioned door gap disruptions may result, for example, by an obstacle which projects into the door gap. Then it is required that any further movement of the roller catch is immediately interrupted and the pressure of the gear acting on the door is cancelled. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to develop a reliable door lock of the kind mentioned in the preamble of claim  1  which, on the one hand, improves the operating comfort but, on the other hand, is of a space-saving configuration. This is achieved according to the invention by one and the same drive motor being used for the closing aid as well as for the opening aid, by a transmission member being arranged in the gear and switchable between two switching positions, by the drive energy exerted by the drive motor reaching the transmission member but, as a function of the switching position of the transmission member, reaching alternatively behind the transmission member the roller catch or the locking pawl via one of two separate drive paths, wherein one drive path belongs to the closing aid and the other belongs to the opening aid. 
     According to the invention, one and the same drive motor can be used for the closing aid as well as for the opening aid. It is sufficient in this context to arrange in the gear a transmission member which can be controlled to alternate between two switching positions. The drive energy provided by the drive motor is transmitted on a common path to the transmission member. Behind the transmission member, however, the drive energy is alternatively guided on one of two separate drive paths. One drive paths belongs to the closing aid and the other to the opening aid. It depends only on the switching position of the transmission member onto which one of the two drive paths the drive energy is directed. Accordingly, the apparatus expenditure is substantially reduced. 
     For reversing the transmission member, it is recommended that the transmission member is secured by a spring force normally in that switching position in which the drive energy exerted by the drive motor is not transmitted to the roller catch, that the transmission member is connected with a switching device which, at a defined limit angle of the roller catch and/or of the pawl, is activated and transfers the transmission member into its other switching position wherein the drive energy exerted by the drive motor acts on the roller catch in the pulling shut direction, and that the switching device is deactivated in a disturbance situation during the pulling shut phase as well as in the main catch position and, by doing so, the transmission member is automatically returned by the spring force again into its switched off position. Usually, the transmission member is secured by a spring force in that switching position in which the drive energy of the drive motor does not reach the roller catch. This normal situation is also present in the open position of the roller catch up to a certain limit angle position of the roller catch as well as in the final main catch position. This limit angle position may be, for example, the pre-catch position of the roller catch. Only when the limit angle position of the roller catch during closing of the door has been reached, a switching device is activated which reverses the transmission member. This switching device engages the transmission member and transfers the transmission member into its other position where the drive energy of the drive motor acts on the roller catch and can pull it shut. 
     In the case of disruption, only the control impulse acting on the switching device must be turned off. Subsequently, the pulling shut phase is simply interrupted in that the switching device releases the transmission member and the latter is returned into its other switching position because of the spring force. Since the remaining gear portion connected to the roller catch is released, the roller catch is no longer arrested and the pressure acting on the door is relieved. Even the effect of the elastic door seals can result in a return movement of the roller catch. After switching of the transmission member has occurred in the pulling shut phase, it may be possible that the drive motor that has been set in motion as well as the drive members, positioned in front of and moved by the transmission member, will move still according to the principle of inertia, but the movement energy of these masses is no longer transmitted onto the roller catch. The roller catch is immediately set still, respectively, it can even rotate in the opposite direction. 
     Of independent inventive importance is the third embodiment according to which, for determining the respective position of the door, control means are provided which comprise two sensors and a control logic connected to the sensors, wherein one sensor responds to a certain angle position of the roller catch, or a certain position of the locking part of the door post supporting the locking part relative to the lock of the door, respectively, and, subsequently, will be referred to as roller catch sensor, while the other sensor responds to the drop of the pawl into the pre-catch as well as into the main catch of the roller catch and is therefore referred to as pawl sensor, and wherein the control logic evaluates commonly the individual signals coming from the two sensors and the different alternatives described in connection therewith. This door lock can also be used independent of a pulling shut aid and/or an opening aid. However, in individual situations the use in connection with a door lock according to the above described first and second embodiments is possible and will also be explained in the following description in more detail. The door lock according to the third embodiment concerns the following problem. 
     It is important to determine the respective position of the door unequivocally in order to, according to this determination, initiate further functions of the vehicle or to control them, for example, the interior illumination of the vehicle. For this purpose, sensors are used. In the past it was required to position the sensors within very tight tolerances for an exact position determination of the door. Moreover, the use of correspondingly exactly operating sensors was required. Finally, the high sensitivity of the sensors should not change during their service life. The manufacture of sensors with such high requirements is difficult and expensive. Moreover, the known sensors had to be exactly mounted which is cost-intensive. The invention avoids these disadvantages by special control means. In this connection the following effects result. 
     Because of the common evaluation of the individual signals of the two sensors, an exact positioning of these sensors with respect to the roller catch or with respect to the pawl is initially not required. Mounting of the sensors is therefore facilitated, faster, and can be performed less expensively. Moreover, the invention makes it possible to even use relatively imprecisely operating sensors because the summation evaluation of the signals allows to determine the respective door position very precisely. According to the invention it is also of no consequence when the sensitivity of the two sensors decreases over the course of time. In this case the summation-based control logic can determine very precisely the point in time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further measures and advantages of the invention result from the claims, the following description, and the drawings. In the drawings, the invention is illustrated in several embodiments. It is shown in: 
     FIG. 1 a  a plan view of the lower part of the inventive lock in the viewing direction of section line Ia—Ia of FIG. 1 c , when the roller catch is still in its open position but the door is on its way to being closed; 
     FIG. 1 b  a plan view onto the lock, in the viewing direction according to arrow Ib of FIG. 1 c;    
     FIG. 1 c  a side view of the lock, wherein the housing is not illustrated; 
     FIG. 1 d  a perspective representation of an important portion of the lock illustrated in FIGS. 1 a  to  1   c;    
     FIGS. 2 a - 2   c  plan and side views of the lock, in analogy to FIGS. 1 a  to  1   c , in a subsequent phase of the closing movement of the door when the locking part entrains the roller catch and has moved it into its pre-catch position; 
     FIGS. 3 a - 3   c  the corresponding plan and side views in that movement phase of the door where the roller catch has been moved motorically by a closing aid according to the invention just into its main catch position and the closing aid is still switched on; 
     FIGS. 4 a - 4   c  the same plan and side views of the lock, wherein the roller catch is also in the main catch position illustrated already in FIGS. 3 a  to  3   c  but the closing aid has been switched off; 
     FIGS. 5 a - 5   c  the aforementioned views of the lock according to the invention after an opening aid has been activated and the roller catch has been returned into the open position illustrated in FIGS. 1 a  to  1   c;    
     FIGS. 6 a - 6   c  a differently embodied door lock of which only the three most important components are illustrated, together with two control means, which allow determination of the respective position of the door reliably; 
     FIGS. 7 a - 7   c  in a representation corresponding to FIGS. 6 a  to  6   c  a variation of the embodiment of the control means; and 
     FIGS. 8 a - 8   d  four alternative tables for the effectiveness of a control logic, correlated with the control means of FIGS. 6 a  to  6   c  and  7   a  to  7   c , for detecting the respective door position. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The configuration of the lock is explained in more detail with the aid of FIGS. 1 a  to  1   d . The door lock comprises a roller catch  11  which is subjected to a restoring force, illustrated by the force arrow  12 , of a spring, not shown in detail. The roller catch  11  is pivotably supported on a bearing pin  15  in a housing, not shown in detail, and is usually fastened on the door, not shown in detail. Instead of a side door, another type of door, for example, the rear hatch of a motor vehicle, could be concerned. The roller catch  11  comprises a slot-shaped receiving device  14  for a locking part  10  which is bracket-shaped in this embodiment. When the locking part is removed from the roller catch  11 , as illustrated at  10 ′ in FIG. 1 a , it is maintained by its spring-load  12  and rotary stops, not illustrated in detail, in an open position illustrated in FIG. 1 a . In this connection, the roller catch  11  with its receiving device  14  remains accessible from the exterior. The locking part  10  is usually fastened on the door post. The arrangement of the locking part  10 , however, can also be on the door, wherein the roller catch  11  is then stationarily positioned with its housing on the post. Based on the release position  10 ′ of FIG. 1 a  illustrated in a dash-dotted line, the locking part  10  moves into the receiving device  14 , when the door is closed, and pivots thus the roller catch  11 , against its return force  12 , in the direction of the pivot arrow  15 , from the open position illustrated in FIG. 1 a  into the pre-catch position illustrated in FIG. 2 a . The roller catch  11  comprises at least two catches  16 ,  17 , i.e., a pre-catch  16  and a main catch  17 . A pawl  20  engages the catches  16 ,  17  with its locking arm  21  when the roller catch  11  is in its already mentioned pre-catch position of FIG. 2 a  or in a final main catch position illustrated in FIG. 3 a.    
     When the pre-catch position of FIG. 2 a  has been reached, usually a gap remains between the door and the door post. The invention is now provided with a motor-driven closing aid. It is embodied in a special way and engages the roller catch. In the pre-catch position of FIG. 2 a  the closing part  10  is already engaged by the roller catch. There is already a positive locking connection between  10 ,  11 . 
     As illustrated by arrows  51 ,  52  in FIG. 2 a , at least two sensors  51 ,  52  are provided wherein one of them ( 51 ) becomes active when the roller catch  11  is in the pre-catch position illustrated in FIG.  2 . The other sensor  52  is activated when the pawl  20  has reached its pivot position illustrated in FIGS. 2 a  and  3   a , wherein the locking arm  21  engages either the pre-catch  16  or the main catch  17 . The sensors  51 ,  52 , when activated, send a signal to a schematically illustrated control logic  50 . The signals are evaluated therein, and for each situation the corresponding activities of the lock are activated which will be explained in more detail in the following. This can be explained more specifically with the aid of the table of FIG. 8 a.    
     The control logic  50  detects the open position of the roller catch  11  of FIG. 1 a  when, according to the table of FIG. 8 a , first line, both sensors  51 ,  52  do not release the signal. This holds true also for the initial rotational path of the roller catch  11  into the position illustrated in FIG. 2 a . However, when the pre-catch position of FIG. 2 a  has been reached, both sensors  51 ,  52 , according to the second column of table of FIG. 8 a , will send a signal. Thus, the control logic  50  will recognize unequivocally that the pre-catch position of FIG. 2 a  has been reached. In the final main catch position of FIG. 3 a  only the second sensor  52  will send a signal but not the first sensor  51 , as can be seen in the last line of the table of FIG. 8 a . This can also be unequivocally detected by the control logic  50 . This operation of the sensors  51 ,  52  with the control logic  50  has the advantage that cumbersome adjustment of the sensors  51 ,  52  with respect to the two sensing locations on the roller catch  11  or the pawl  20  are no longer needed. Suitable sensors are members, for example, Hall sensors, which respond to permanent magnets provided on  11  or  20  and entrained therewith. 
     When the roller catch  11  has reached its pre-catch position illustrated in FIG. 2 a , the control logic  50  will activate the “closing aid” until the main catch position of FIG. 3 a  has been reached. Then the closing aid will be deactivated which results in the position of the components illustrated in FIGS. 4 a  to  4   c . The switching on and switching off of the closing aid is realized by the components of the lock according to the invention which are designed in a special way. 
     As can be seen best in FIGS. 1 d  and  1   b ,  1   c , the closing aid comprises in this embodiment an electrically operated drive motor  30  having arranged downstream thereof a reduction gear comprised of several members. They include a worm gear  31  rotatably driven by the motor  30  which engages a worm wheel  32 . The worm wheel  22  is connected fixedly with the spur gear  33  for common rotation. Downstream of the spur gear  33  a special transmission member  35  is provided which in the present case is comprised of a tumbler wheel. The transmission member  35  can be switched between two switching positions, one of which is illustrated in FIG. 1 c  and the other in FIG. 2 c . As can be taken from these Figures, the dash-dotted line illustrating the axle  40  of the tumbler wheel has two angle positions that differ from one another. The lower axle end indicated with  41  in FIG. 1 c  is shaped like a ball joint at a defined location in the lock housing, not illustrated in detail, while the oppositely positioned other axle end  42  is tiltingly movable and is pivotably supported on a switching device  60 . The switching device comprises first a rocker  61  which is pivotably supported in the housing at  62 , and is connected via a crank guide  63  with a toothed gear segment  64 . The toothed gear segment  64  meshes with a pinion  66  of the motor  65  which is referred to as a “coupling motor” for reasons which will be disclosed in the following. 
     The tiltable axle end  42  of the tumbler wheel  35  in the present case is under the effect of a spring force indicated by the arrow  44  which has the tendency to maintain the axle  40  in the pivoted position, indicated in FIG. 1 c , relative to the spur gear  37  arranged downstream. In this connection, an upper toothing  36  provided at the tumbler wheel reaches a decoupled position relative to the spur gear  37 . On the other hand, a lower toothing  34  of the tumbler wheel  35  in this case remains still in engagement with the already mentioned spur gear  33  of this gear system. FIG. 1 c  accordingly corresponds to a switch-off position of the transmission member  35 . The spring force  44  engages in a concrete embodiment on the pin  43  of the two segments  64 , which pin is illustrated in FIGS. 1 b  and  1   d . The tooth segment  64  is supported in the housing at location  67 . A guide pin  68  provided on the rocker  61  comes to rest against one end of the crank guide  63 , and this determines the switch-off position of the tumbler wheel  35  relative to the aforementioned downstream spur gear  37  of the gear system. In FIGS. 1 a  to  1   d  the drive motor  30  as well as the coupling motor  65  are standing still. 
     Upon further closing of the door, the locking part  10  entrains the roller catch  11  and brings it into the pre-catch position illustrated in FIGS. 2 a  to  2   c  where, as mentioned above, the pawl  20  drops into the pre-catch  16  of the roller catch  11 . This fact, as has already been disclosed above, is detected by the sensors  51 ,  52  and reported to the control logic  50  which transfers the aforementioned transmission member  35 , formed as a tumbler wheel, into the other position illustrated in FIG. 2 c . Now the tumbler wheel  35  engages with its upper toothing  36  with the already mentioned spur gear  37 . This provides a “switched-on” position of the transmission member  35 . Now the drive motor  30  is supplied with electrical current. 
     The drive energy of the motor  30  transmitted via the gear members  31 ,  32 ,  33  to the transmission member  35  is now further guided by the output path arranged downstream of the transmission member  35  of the pulling-shut aid. This output path includes the already mentioned spur gear  37  which is fixedly connected on a pinion  38  for common rotation. Also provided is a toothed gear segment  39  engaging the pinion  38  und fixedly connected to a shaft  53  for common rotation. Moreover, an output member  54  of this output path is fixedly connected to the shaft  53  which, in the present case, is in the form of a lever. The lever  54  is supported with its free end on the shoulder  55  illustrated in FIG. 2 a . The drive energy coming from the motor  30  results in a drive force provided via the transmission chain  31  through  39  and  53 ,  54  illustrated by the arrow F 1 . It has the effect that the roller catch  11  is entrained and moved further in the direction of the pivot arrow  15  of FIG. 2 b . The locking part  10  engaging the roller catch  11  is also entrained until the main catch position of the roller catch  11  illustrated in FIG. 3 a  is reached. By means of the locking part  10  the door has been closed by motor forces according to the pulling shut arrow  18  illustrated in FIG. 3 a . The gap of the door which was present up to this point is now closed. 
     In FIGS. 3 a  to  3   c  the pulling shut movement  18  is still illustrated in its end phase where there is still a drive connection between the motor  30  and the output member  54  of the gear via the activated transmission member  35 . In this last phase, the lever  54  provides a drive force F 2  which provides a greater torque onto the roller catch  11  than in the case of the pre-catch position illustrated in FIG. 2 a  for the following reason. 
     The shoulder  55  for receiving the force F 1  in FIG. 2 a  is the profiled end of an arc-shaped rib  56  seated on a disk surface of the roller catch  11 . The contact location is indicated by  57  in FIG. 2 a . The arm length r 1  between the drive-active lever  54  and the contact location  57  on the control end  55  of the rib  56  is relatively small. The drive moment results thus as a product of r 1  and F 1 . The corresponding torque acting on the catch roller  11  is determined by the torque arm r illustrated by a dash-dotted line in FIG. 2 a  and longer than r 1  but also by the force component F 1 ′ which is smaller than F 1 . However, this ratio changes along the path to the main catch position of the roller catch  11  of FIG. 3 a.    
     In FIG. 3 a  the contact location between the lever  54  and the shoulder  55  through  57 ′ has been moved so that the corresponding arm length r 2  of the torque exerted by  54  has become smaller. The spacing between the contact location  57 ′ and the axis  13  of the roller catch  11  is in approximation identical to that of FIG. 2 a . However, the force direction of F 2  has also changed. The drive force F 2  exerted by the lever  54  now acts fully on the roller catch  11 , at least, however, with a substantially greater force component in comparison to FIG. 2 a . The efficiency of the applied force F 2  in comparison to F 1  and F 1 ′ has become greater. The torque acting on the roller catch  11  in FIG. 3 a  is greater relative to FIG. 2 a . The multiplication ratio of the gear between the drive motor  20  and the roller catch  11  has increased upon transition from FIG. 2 a  to FIG. 3 a . The pulling force acting on the locking part  10  for pulling the door shut in the direction of arrow  18  has become greater. 
     This increase of the pulling force is very desirable. Between the door and the door frame there are, in general, elastic seals which in the last phase of the door closing movement must be compressed and therefore present a resistance to the pulling shut force. The thus resulting counter force increases thus in the last phase of the closing movement of the door. Also, the return force  12  acting on the roller catch  11  increases in this last movement phase. Accordingly, the sum of the counter forces, which occur during closing of the door and which must be overcome by the pulling shut aid, increases. Without the aforementioned increase of the pulling force according to the invention the operating point of the drive motor  30  which is embodied as a DC motor would be displaced because of the increasing counter force. Accordingly, a smaller rpm would result in accordance with the operating characteristic line of the motor  30  as a result of the increased motor load. The rpm determines however the motor noise. A change of rpm thus results in a change of the motor noise to lower frequencies, which is perceived as uncomfortable. 
     According to the invention, it is easily possible with the aforementioned means to compensate the increase of the counter force so that the rpm of the drive motor during the entire pulling shut phase is substantially maintained constant. During pulling shut of the door this results in a very pleasant, uniform motor noise. The invention thus makes it possible to operate the drive motor  30  during the entire pulling shut movement substantially at the same operating point of its characteristic line. 
     When, as already disclosed, the sensors  51 ,  52  have recognized the main catch position of FIG. 3 a , the control logic moves the described transmission member  35  again into its switched-off position which can be seen in FIGS. 4 a - 4   c . The tumbler wheel  35  in FIG. 4 c  is again in the angular position with its axis  40  pivoted away. This is carried out in that the switching device  60  is made inactive. For this purpose, the coupling motor  65  must only be switched off. This can have an effect on the spring force  44  acting on the transmission member  35 , against which previously the switching device  60  had worked by applying an electric current to the coupling motor  65 . Because of the described point of attack of the spring force  44  on the pin  43  of the toothed gear segment  64 , the toothed gear segment  64  is moved back from its position in FIG. 3 b  into the position of FIG. 4 b . Accordingly, the guide pin  68  of the rocker  61  is moved to the other end of the crank guide  63  of the two gear segment  64 . 
     This switched-off position of the transmission member  35  from the aforementioned further drive path  37  to  39  and  53 ,  54  is especially of great importance when during the previously described pulling-shut phase between FIG. 2 a  and  3   a  an emergency situation occurs which requires that the further closing of the door is immediately stopped. Such an emergency situation can be detected by the electric control logic in that, for example, the time required for the pulling shut process has been exceeded or that the electric current for driving the drive motor  30  has increased past a permissible limit or that power failure occurs. In this case, already on the way to the main catch position of the roller catch  11  of FIG. 3 a , the current supply of the coupling motor  65  is switched off. Already on the path, before reaching FIG. 3 a , a decoupling of the transmission member  35  from the drive path  37  to  39  and  53 ,  54  of the pulling-shut aid positioned downstream is carried out. Even when according to the inertia principle the drive motor  30  set in motion and the moved drive members  31  to  33  in front of the transmission member  35  continue to run, the movement energy of these masses is no longer transmitted onto the roller catch  11 . The roller catch  11  no longer moves any farther, it can even be returned for the following reason. 
     Because of the elastic effect of the already mentioned door seals a counter force results. This counter force is sufficient in any case to move the roller catch  11  in an emergency situation again into its pre-catch position of FIG. 2 a . Such a switching off of the transmission member  35  can, of course, also be achieved by a manual actuation of an inner grip belonging to the door lock, an outer grip, or a remote control. In the main catch position of the roller catch  11  of FIG. 4 a  to  4   c , of course, the drive motor  30  is also automatically switched off by the control logic. 
     The invention is also provided with an opening aid which can be activated by actuation of the inner or outer handle of the door or by actuation of a remote control. When pulling shut the door, the opening aid can also be actuated by the vehicle user. When desired, the opening aid can also be actuated automatically by the control logic  50  when the aforementioned emergency situation during closing of the door is present. In the switched-off position of FIG. 4 c  with respect to the spur gear  37  belonging to the pulling shut aid, the transmission member  35 , as shown in FIG. 4 c , is actually in connection with the following drive path provided as the opening aid. 
     In this case, according to FIG. 4 c , the lower toothing  34  of the tumbler wheel  35  is still in engagement with the upstream spur gear  33 . Accordingly, a rotation of the drive motor  30  is now transmitted via the upper toothing  36  of the tumbler wheel  35  onto another spur gear  45  which is fixedly connected for common rotation to a shaft  46 . 
     The drive motor  30  rotates by the way in the same rotational direction as the previously described pulling shut aid according to FIGS. 2 a  to  3   c . The upper end  67  of this shaft  46  can serve at the same time as the aforementioned bearing for the toothed wheel segment  64  belonging to the switching device  60 . A control cam  47 , illustrated in FIG. 4 a , is fixedly connected to the shaft  46  and forms the output of the drive path  45 ,  47  belonging to the opening aid. In FIG. 4 a  the rest position of this control cam  47  is illustrated. In this connection, the control cam  47  is supported on a control surface  23 , shown in FIG. 4 a , of a further lever  22  onto which the force  25  of a two-leg spring  24 ,  24 ′ acts. One spring leg  24 ′ is supported on a stationary support location  26  in the housing while the other leg  24  provides the spring force  25 , indicated in FIG. 4 a  by the arrow  25 , acting on the lever  22 . The spring  24 ,  24 ′ represents a force storage for the lever for which reason the lever  22  in the following will be referred to as “storage lever”. 
     In the initial position of FIG. 4 a  the spring force  25  of the storage lever  22  cannot yet act on the pawl  20  because, as mentioned above, the control cam  47  supports the storage lever  22  on its control surface  23 . However, this will change when for activation of the opening aid the drive motor  30  is further supplied with electrical current. Then the control cam  47  according to FIG. 4 a  is moved in the direction of the rotational path  27  via the aforementioned second drive path  45  to  47  and releases increasingly the storage lever  22 . The pawl  20  is also under a spring load  28  in the counter direction as illustrated by arrow  28 ; even though, the higher spring force  25  exerted by the storage lever  22  is normally sufficient in order to lift the locking arm  21  of the pawl  20  out of the main catch  17  of FIG. 4 a  or the pre-catch  16  of FIG. 2 a . The force transmission between the storage lever  22  and the pawl  20  is realized via the contact surface and counter contact surface  49 ,  49  according to FIG. 4 a . Then the roller catch  11  is free and can be returned by the restoring force  12  acting on it into its open position of FIG. 1 a . Now the locking part  10  is again released and the door can be opened. 
     The end phase of the opening movement can be seen in FIGS. 5 a  to  5   c . The locking part  10  has moved away relative to the roller catch  11 , in comparison to the situation of FIG. 4 a , in the direction of the opening arrow  19  of FIG. 5 a . The roller catch  11  has returned into the open position as a result of its restoring force  12 . The locking part  10  has been released from the receiving device  14  in the roller catch  11 . The rotation  27  of the control cam  47  described in FIG. 4 a  is usually completed even before the control cam has reached a counter control surface  29  which, in this embodiment, is located on an extended arm of the pawl  20 . In a crash situation, however, or in other disturbances, it may occur that the pawl locking arm  21  is seated so tightly in the main catch  17  of the roller catch  11  that the spring force  25  of the locking lever  22  is not sufficient for releasing the pawl  20 . This is detected by sensors, for example, the described pawl sensor  52 . The drive motor  30  turns past the rotational position of the cam  47  illustrated in FIG. 5 a . This is illustrated in FIG. 5 a  by the dashed arrow  27 ′. The cam  47  contacts, either in the case of the pawl engagement at  17  illustrated in FIG. 4 a  or at  16  in FIG. 2 a , the aforementioned counter control surface  29  and forces the pawl locking arm  21 , with enhancement by the storage spring force  25 , out of the main catch  17  or pre-catch  16 . 
     After lifting the pawl  20  in the described disturbance situation or in the previously described normal situation of FIGS. 5 a  to  5   c , the control cam  47  is again returned by the motor, in particular, in the direction of the counter rotation arrow  48  illustrated in FIG. 5 a . This is again made possible by the drive motor  30  because there is still a drive connection with the drive path  45  to  47  of the opening aid of the gear. For this purpose, the motor  30  must only be supplied with electric current in the opposite direction. The control cam  47  then again meets the control surface  23  of the storage lever  22  and moves it under tension of the movable spring leg  24  again into the rest position of FIG. 1 a . All of this can again be monitored by sensors. When the storage lever  22  is again in its initial position of FIG. 1 a , the counter current loading of the drive more  30  for this counter rotation  48  is stopped. 
     As has been mentioned already, the left position of the roller catch  11  according to FIG. 1 a  to  1   d  of the first drive path  37  to  39  as well as  53 ,  54 , belonging to the pulling shut aid and positioned downstream of the transmission member  35 , is switched off. This gear portion is free. This results already after switching off the transmission member  35  in the main catch position of the roller catch  11  of FIG. 4 a  to  4   c . At this point, no drive force coming from the drive motor  30  is exerted on the lever  54 . It can rest in the open position of FIG. 1 a  or  5   a  on the inner arc surface  58  of the rib  56 . A light spring tension acting on the lever  54  provides a defined position of the lever  54  on this arc surface  58 . This light spring tension also makes sure that, already before the beginning of the pulling shut movement according to FIG. 2 a  to  2   c , the lever  54  is positioned at the described contact location  57  of the shoulder  55  according to FIG. 2 a.    
     For releasing the pawl  20  via an outer and/or inner handle or a remote control, a point of attack is provided, for example, a release pin  59  as illustrated in FIGS. 4 a  and  4   c . Otherwise, the aforementioned counter control surface  29  can be provided, instead of on the pawl  20 , on the storage lever  22  and can be a monolithic, fixed component of the storage lever  22 . In this case, the pawl  20  is shortened in its length relative to that of FIGS. 1 a  to  5   a . In this case, the contact surface  49  on the storage lever  22  and the correlated counter contact surface  69  on the pawl  20  according to FIG. 4 a  are, however, maintained in order to be able to transmit the spring force  25  of the storage lever  22  as an opening aid onto the pawl  20 , as has been disclosed above. The one-part connection of the control and counter control surfaces  23 ,  29  on the storage lever  22  can be provided in the form of an eye at the lever end area of the storage lever  22 , wherein the control cam  47  engages the eye opening. The eye has approximately an elongate oval shape with profiled edges. The control cam  47  then has a profiled contour. The control and counter control surfaces  23 ,  29  are then positioned at oppositely arranged edges of this eye. This configuration has special advantages and, independent of the embodiments of the aforementioned Figures, has its own inventive importance. 
     As has been mentioned above, the control means for determining the respective position of the door, as disclosed in connection with FIGS. 1 a  to  5   c  and explained in connection with the table according to FIG. 8 a , have independent inventive importance. They can also be used in connection with a door lock that has neither a pulling-shut aid nor an opening aid or is provided only with an opening aid. The resulting advantages have already been disclosed in detail in the introductory portion of the description. The FIGS. 6 a  to  6   c , on the one hand, and FIGS. 7 a  to  7   c , on the other hand, show, based on the most important components of such door locks, two possibilities for the configuration of the control means. 
     In FIG. 6 a  only the roller catch  11 , the pawl  20  which has been changed as disclosed in the last embodiment, and the two described sensors  51 ,  52  of a door lock  70  are shown. The sensors  51 ,  52  can be of any suitable configuration as is known in the art. They can be comprised of a mechanical or optical switch, a reed contact, a Hall sensor or other so-called sensor wire elements. The position illustrated in FIG. 6 a  corresponds to that of FIG. 1 a  which has been explained already with the aid of FIG. 8 a , line  1 . In this case, both sensors  51 ,  52  do not send a signal to the corresponding control logic  50 , which is shown in FIG. 1 a  while in FIG. 6 a  only the electrical connecting lines  71 ,  72  extending to the sensors are illustrated. The open position of the door is now unequivocally determined. 
     The situation of this door lock  70  illustrated in FIG. 6 b  corresponds to the door position already explained in connection with FIG. 2 a . The locking part  10  is already positive-lockingly engaged by the roller catch  11  and the pawl  20  has dropped with its locking location  21  into the pre-catch. The roller catch  11  as well as the pawl  20  have flaps  73  and  78 , respectively, which in this door position reach into the area of the sensors  51 ,  52 . Subsequently, as already explained in connection with the curve  8   a , the pre-catch position of the door is detected because both sensors  51 ,  52  send a signal to the control logic  15  which is not shown in detail in FIG. 6 b.    
     In FIG. 6 c  the main catch position of the door is present which has already been explained in connection with FIG. 4 a . The locking location  21  of the pawl  20  is then in the aforementioned main catch  17  of the roller catch  11 . The door is not completely closed. This is detected by means of the signals sent by the two sensors  51 ,  52  to the control logic  50 , as has been explained above in connection with the last line of FIG. 8 a . This can be seen in FIG. 6 c  in that the aforementioned flap  74  at the pawl  20  results in the signal “ 1 ”. At the roller catch sensor  51 , on the other hand, the corresponding flap  73  is removed and, instead, a cutout  75  of the roller catch  11  is in alignment with the sensor  51 . Accordingly, the sensor  51  is not activated. The control logic  50  in this scenario only receives the signal “ 0 ” from the sensor  51 , as can be seen in the table of FIG. 8 a.    
     In FIG. 7 a  to  7   c  an alternative embodiment of the door lock  70 ′ is shown, in particular, again in the same three positions as explained supra in connection with the lock  70  in FIG. 6 a  to  6   c . Therefore, the above description applies here also. It is sufficient to only point out the differences. 
     In the door lock  70 ′ of FIGS. 7 a  to  7   c  only the bolt  76  of the locking part  10  is illustrated which has not yet been engaged by the receiving device  14  of the roller catch  11  in the open position illustrated in FIG. 7 a . This bolt  76  could be formed by one leg of a bracket-shaped locking part  10  as is illustrated perspectively in FIG. 1 d . In deviation from the previously disclosed door lock  70  the sensor  51  in the door lock  70 ′ of FIG. 7 a  to  7   c  does not cooperate with the roller catch  11  but with the locking bolt  76 . Accordingly, in the door lock  70 ′ the aforementioned flap  73  of FIGS. 6 a  to  6   c  can be eliminated. In analogy to FIGS. 6 a , the sensor  51  in door lock  70 ′ sends the signal “ 0 ” to the control logic  50  in the position illustrated in FIG. 7 a.    
     When the door is in the pre-catch position according to FIG. 7 b , the locking bolt  76  has reached the area of the corresponding sensor  51 , and, therefore, a positive signal is sent to the corresponding control logic  50 . Such a positive signal is provided because of the already described position of the pawl flap  74 , provided also in the lock  70 ′, at the pawl sensor  52 , as has already been described in connection with FIG. 6 b.    
     In FIG. 7 c  the main catch position of the door is now present. The locking bolt  76  has been removed from the sensor  51  so that again the signal “ 0 ” is provided. For the same reason as in FIG. 6 c , the pawl sensor  52  in this case provides a positive signal. 
     In FIGS. 8 b  to  8   d  three further tables for the control logic  50  are listed which may result for a variation of the embodiment of the door locks  70  or  70 ′. As can be seen in the tables, the signals in the different positions are correlated in a different way relative to FIG. 8 a , but they are always unequivocal for the control logic. Therefore, as has been explained in connection with FIG. 6 a  to  7   c , the logic can unequivocally detect each of the three positions of the door based on the signals. In order to obtain these signal variations in the three different door positions, it is only necessary to position the two sensors  51  and  52  differently relative to the afore described control locations  73 ,  74 ,  75  of the roller catch  11  and the pawl  20  or relative to the control bolt  76 . Another possibility is, of course, to position these control locations  73  to  76  differently while taking over the positions according to FIG. 6 a  to  7   c  for the two sensors  51 ,  52 . 
     LIST OF REFERENCE NUMERALS 
       10  locking part 
       10 ′ release position of  10   
       11  roller catch 
       12  arrow of restoring force of  11   
       13  bearing pin of  11 , rotary axis 
       14  receiving device of  11  for  10   
       15  pivot arrow of  11  for closing or pulling shut 
       16  pre-catch of  11   
       17  main catch of  11   
       18  arrow of pulling shut movement of door (FIG. 3 a ) 
       19  arrow of opening movement of door (FIG. 5 a ) 
       20  pawl 
       21  locking arm of  20 ; locking location 
       22  storage lever 
       23  control surface on  22   
       24  first movable spring leg for  22   
       24 ′ second supported spring leg for  22   
       25  arrow of spring force of  24  (FIG. 4 a ) 
       26  support location of  24 ′ (FIG. 4 a ) 
       27  arrow of rotational movement of  47  for releasing  22   
       27 ′ further rotation of  47  in a crash situation (FIG. 5 a ) 
       28  arrow of own spring-load of  20   
       29  counter control surface on  20  for  47  (FIG. 4 a ) 
       30  drive motor 
       31  worm gear 
       32  worm wheel 
       33  spur gear 
       34  lower toothing of  35   
       35  transmission member, tumbler wheel 
       36  upper toothing of  35   
       37  spur gear, pulling shut drive path 
       38  pinion, pulling shut drive path 
       39  tooth gear segment, pulling shut drive path 
       40  axle of  35   
       41  first stationary axle end of  40   
       42  second movable axle end of  40   
       43  pin on  64  for  44   
       44  arrow of spring force for  35   
       45  spur gear, opening drive path 
       46  shaft, opening drive path 
       47  control cam, opening drive path 
       48  arrow of counter rotation of  47  (FIG. 5 a ) 
       49  contact surface on  22  (FIG. 4 a ) 
       50  control logic 
       51  first sensor, roller catch sensor 
       52  second sensor, pawl sensor 
       53  shaft, pulling shut drive path 
       54  output member of pulling shut drive path, lever 
       55  shoulder for  54 , control end of  56   
       56  arc-shaped rib on the  11  (FIG. 2 a ) 
       57  first contact location between  55 ,  54  (FIG. 2 a ) 
       57 ′ second contact location between  55 ,  54  (FIG. 3 a ) 
       58  inner arc surface of  56  (FIG. 1 a ) 
       59  release pin on  20  (FIGS. 4 a ,  4   c ) 
       60  switching device 
       61  rocker of  60   
       62  bearing of  61   
       63  crank guide in  64   
       64  tooth gear segment 
       65  coupling motor for  60   
       66  pinion 
       67  bearing of  64 , shaft end of  46   
       68  the guide pin on  61  for  63   
       69  counter contact surface on  20  (FIG. 4 a ) 
       70  door lock (FIGS. 6 a  to  6   c ) 
       70 ′ door lock (FIGS. 7 a  to  7   c ) 
       71  electric line for  51   
       72  electric line for  52   
       73  flap on  11  (FIG. 6 b ) 
       74  flap on  20  (FIG. 6 b ) 
       75  cutout on  11   
       76  locking bolt of  10  at  70 ′ (FIGS. 7 a  to  7   c ) 
     F 1  drive force of  54  (FIG. 2 a ) 
     F 1 ′ force component of F 1  for  11  (FIG. 2 a ) 
     F 2  drive force of  54  (FIG. 3 a ) 
     r arm length vpm drive moment for  11  (FIG. 2 a ) 
     r 1  arm length for drive torque of  54  (FIG. 2 a ) 
     r 2  arm length for drive torque of  54  (FIG. 3 a )