Patent Document

CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to International Application No. PCT/EP2007/010303, filed Nov. 28, 2007, which is based on and claims priority to German Patent Application No. DE 10 2006 057 018.9, filed Dec. 2, 2006. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a self-locking belt retractor for motor vehicles, with a vehicle-sensitive and a belt-webbing-sensitive control system for a locking device of the belt retractor. The belt retractor includes a toothed wheel able to be guided into a toothing fixed to the housing of the belt retractor, wherein the control system comprises a control disc rotating with the belt shaft. The control disc is coupled to the toothed wheel and in order to form its inertia, the control disc is constructed with an inertial mass swivellably mounted thereon for the formation of the belt-webbing-sensitive control. The control disc includes an outer toothing for engaging a sensor lever arranged on a vehicle sensor, wherein at least one locking lever being controlled by rotation of the belt shaft, and swivellable between an activation position and a cutoff position, is provided for the cutoff of the vehicle sensor in a functional range in which almost the entire safety belt is wound on the belt shaft, and wherein an arrangement is provided for the cutoff of the belt-webbing sensitive control in the functional range of the belt retractor. 
       BACKGROUND OF THE INVENTION 
       [0003]    A belt retractor with the above-mentioned features is described in DE 103 60 032 A1. In order to prevent a blocking mechanism of the belt retractor from blocking a belt spool at the end of the winding of a safety belt after the safety belt has been taken off by a vehicle occupant and the safety belt is rolled up under the action of a winding spring (or when the safety belt is abruptly braked), the above-mentioned publication provides a cutoff (or disabling) of the belt-webbing-sensitive and the vehicle-sensitive control system so that an undesired blocking of the belt shaft at the end of the winding of the safety belt is prevented. 
         [0004]    For this, in the known belt retractor, a locking disc is arranged on the belt shaft and is rotatable therewith, wherein the locking disc controls, by means of a guide curve arranged on it, a locking lever which is swivellably mounted in a fixed manner relative to the housing of the belt retractor. In a functional range in which almost the entire safety belt is wound on the belt shaft, the locking lever acts directly on a sensor lever of a vehicle sensor cooperating with a control disc, and secures it, thereby cutting off the vehicle-sensitive control system. Insofar as the belt-webbing-sensitive control system is realized by the control disc, wherein the control disc is constructed with a corresponding mass moment of inertia, a blocking catch mounted on the belt shaft is provided to cut off the belt-webbing-sensitive control system. For its actuation, the blocking catch is coupled via a guide link to the locking lever for the cutoff of the vehicle sensor. When the blocking catch is in its blocking position, brought about by the locking position of the locking lever, it is in engagement with the control disc and locks the control disc so as to be locked against relative rotation with the belt shaft. 
         [0005]    Furthermore, the known belt retractor has an Automatic Locking Retractor (ALR) and/or an Emergency Locking Retractor (ELR) switchover for setting a child safety function, which is controlled by the locking disc by means of switching (or trip) cams constructed thereon. In the ALR switching position, which is activated by almost complete withdrawal of the safety belt for securing a child&#39;s seat to the vehicle seat, the control disc is locked on a toothing fixed to the housing, so that on withdrawal of the seat belt in the ALR switching position, owing to the stationary control disc, a blocking of the belt retractor is immediately triggered. 
         [0006]    The known belt retractor entails the disadvantage that for the cutoff of both the vehicle-sensitive and of the belt-webbing-sensitive control system, various levers are provided, whereby the construction of the belt retractor is complicated and the manufacturing expenditure is correspondingly great. In addition, the cutoff of the two control systems can only take place in succession, because the actuation of the locking lever for the vehicle sensor is a precondition for the controlling of the blocking catch for the belt-webbing sensitive control system. As several control processes are necessary, there exists a corresponding potential for error. 
         [0007]    Therefore, one object of the present invention is to simplify a self-locking belt retractor with regard to the cutoff of the vehicle-sensitive and also of the belt-webbing-sensitive control system, and to improve the reliability of the cutoff function accordingly. 
         [0008]    The solution to this task, including advantageous developments and further developments of the invention, can be seen from the content of the claims, which follow this description. 
       SUMMARY OF THE INVENTION 
       [0009]    In its basic idea, the invention provides that for the formation of inertia on of the control disc, an inertial mass is swivellably mounted thereon, and is deflectable into a blocking position for the control disc. Additionally, a locking lever for disabling a vehicle sensor is also mounted on the control disc. According to a switching process in a cutoff position of the locking lever, the locking lever cuts off the vehicle sensor and also secures the inertial mass in a disabling position which is different from the blocking position. Unlike the prior art, the mass moment of inertia of the control disc is produced by an inertial mass which is pivotably mounted on the control disc, whereby the vehicle sensor is cut off and the inertial mass is secured from potential movement by way of a single locking lever, and wherein the belt-webbing-sensitive control system is cut off at the same time. Accordingly, the invention also entails the advantage that only a single component and a single switching process are necessary in order to cut off (or disable) both control systems together. As the locking lever is likewise mounted on the control disc itself, all the components necessary for the cutoff are concentrated on the control disc, so that the structure of the belt retractor is simplified. 
         [0010]    With regard to the cutoff of the vehicle sensor, an exemplary embodiment of the invention provides that the control disc is constructed in two parts. First, the control disc includes a rotatable platform coupled to the belt shaft, wherein the platform acts as a carrier for the inertial mass and the locking lever. Secondly, the control disc includes an outer ring rotatable with respect to the platform. The outer ring has an outer toothing for engaging the sensor lever of the vehicle sensor, and an inner toothing for engaging the locking lever in its activation position. Insofar as the sensor lever of the vehicle sensor (arranged outside the control disc) engages onto the outer teeth of the separate ring, the locking lever is in engagement with the inner toothing of the ring in the functional position of the control disc, so that in this position of the locking lever, an externally toothed locking disc according to the prior art is formed. In this respect, it is merely necessary for the cutoff of the vehicle-sensitive control system to guide the locking lever out of engagement with the inner toothing of the separate ring, because here, even in the case of an engagement of the sensor lever into the outer toothing of the ring, the platform rotates as carrier of the locking lever with respect to the ring, so that the control disc rotates further with the belt shaft. As such, the necessary relative rotation between the control disc (or platform) and the belt shaft to initiate the blocking of the belt retractor does not occur. 
         [0011]    With regard to the construction of the belt-webbing-sensitive control system by means of an inertial mass pivotably mounted on the control disc, provision is made that the inertial mass has a blocking tooth arriving in its blocking position in engagement with a peripheral toothing formed on the inner side on a housing cap overlapping the control system. In this respect, the belt-webbing-sensitive control system is realized in that with the occurrence of a correspondingly high rotational acceleration of the control disc or of the platform as carrier of the inertial mass, the inertial mass is deflected and its blocking tooth comes in engagement with the toothing which is fixed to the housing. Thus, the inertial mass is hereby secured and since it is mounted on the platform of the control disc, the inertial mass stops further rotational movement of the control disc, thereby initiating the relative rotation between the platform of the control disc and the belt shaft, which is necessary for the blocking of the belt retractor. 
         [0012]    Through the swivelling of the locking lever, therefore, with a switching process necessary for the function of the vehicle sensor, the ring of the control disc is released and the inertial mass is secured against potential swivelling, so that with one switching process both control systems are disabled. 
         [0013]    Insofar as the belt retractor of the present invention corresponds to the prior art in that in addition to the belt-webbing-sensitive and the vehicle-sensitive control system, the belt retractor must also have an ALR/ELR switchover, an exemplary embodiment of the invention provides an additional switching lever swivellably mounted on the control disc for the ALR/ELR switchover between two switching positions. In the ALR switching position, the switching lever is configured to engage with the peripheral toothing of the housing cap, and in the ELR switching position, the switching lever is not in engagement with the peripheral toothing. Since the switching lever for the ALR/ELR switchover is mounted on the control disc itself or on the associated platform, the structural expenditure is correspondingly reduced. With regard to the function of the ALR/ELR switchover, details and illustrations are disclosed in DE 103 60 032 A1, the disclosure of which is hereby incorporated by reference in its entirety for all purposes. 
         [0014]    According to an exemplary embodiment of the present invention, insofar as the switching lever does not engage with the peripheral toothing of the housing cap during the ELR switching state, provision is made that the switching lever is secured with a spring arm on a structural part of the control disc, wherein in its radially deflected ALR switching position, the spring arm comes out of engagement with the structural part of the control disc. Owing to the spring engagement, which is thus set, incorrect controlling of the switching lever is avoided. 
         [0015]    For the controlling of both the locking lever and of the switching lever, reference is made to the principle disclosed by DE 103 60 032 A1 of controlling the respective levers via cams. In this regard, an exemplary embodiment of the present invention provides for simultaneously controlling both the locking lever and the switching lever of a wobble plate with cams formed thereon, wherein the wobble plate is arranged adjacent to the control disc and is driven by the belt shaft. In particular, guide pins, respectively formed on the locking lever and on the switching lever, are provided and guided on the cams. 
         [0016]    With regard to the driving of the wobble plate, an exemplary embodiment of the invention provides that the wobble plate is placed with an eccentrically arranged, internally toothed bearing bore on an externally toothed extension of the control disc, so that the rotary movement of the control disc together with the belt shaft can be converted into rotary movement of the wobble plate. To fix the wobbling movement of the wobble plate, the wobble plate is guided in a bearing formed eccentrically in the housing cap. In this way, the wobbling rotation of the wobble plate respectively provides a measurement for the winding or unwinding status of the belt webbing, which may be converted to control the locking lever and switching lever. 
         [0017]    With regard to the cams formed on the wobble plate for controlling both the locking lever and the switching lever, an exemplary embodiment of the invention, provides that the wobble plate has a strip extending at least over a partial circumference and projecting axially into the plane of the guide pins of the locking lever and switching lever, and a bearing ring projecting parallel to the strip, the bearing ring being provided for the formation of the cams for controlling the guide pins. According to one aspect of the invention, the strip is arranged with a radial distance from both the bearing ring and the outer periphery of the wobble plate, and on its inner side a cam is formed and on its outer side a cam is formed for the guide pin of the locking lever. Additionally, at least one opening is provided as a radial transition section for the passage of the guide pin between the inner cam and the outer cam. 
         [0018]    Therefore, through the arrangement of the strip with the cams formed on it, two regions on the wobble plate are separated from each other, in which the movements of the two guide pins, which are controlled by the wobble plate, take place according to the unwinding status of the belt webbing. Here, due to the radial displacement of the wobble plate taking place in combination with the rotary movement of the wobble plate, the cams are formed so that the cams have an undulating contour on their running paths for the guide pins of the locking lever and switching lever, wherein the undulating contour is configured to equalize movement of the wobble plate with respect to the guide pins of the locking lever and switching lever, rotating with the control disc. 
         [0019]    According to one embodiment of the invention, the strip with the cams formed thereon extends over the entire periphery of the wobble plate such that the guide pin of the locking lever is guided on the cams during the entire winding and unwinding movement of the belt webbing. 
         [0020]    In particular, at the start of the belt webbing withdrawal, with a very high withdrawal acceleration (e.g., a withdrawing acceleration exceeding a predetermined value), the guide pin of the locking lever can strike so powerfully against the inner guide curve of the strip that the guide pin breaks off; in such a case, further use of the belt retractor would no longer be guaranteed, because the locking lever would no longer be able to be controlled to produce the control disc function. In order to provide a remedy here, provision can be made that the strip with the cams formed thereon extends only over a partial region of the periphery of the wobble plate, which is traveled through by the guide pin of the locking lever after initial belt webbing withdrawal in its position guided outwards in engagement with the inner toothing of the ring. In the remaining peripheral region, radially outward directed cross-pieces, spaced apart from each other, are arranged on the wobble plate to receive the guide pin of the locking lever between them. If the belt were accordingly withdrawn with a very high initial acceleration, then the guide pin of the locking lever can move between the radially aligned cross-pieces and not be stressed in this respect. At the same time, however, the belt-webbing-sensitive control system would respond with a deflection of the inertial mass, in which a blocking of the belt shaft against further belt withdrawal would occur. In order to release the blocking, the belt webbing must be slackened before a slower withdrawal movement can then take place again without stressing the guide pin which is situated on the locking lever. 
         [0021]    For further protection of the guide pin of the locking lever, provision can be made in such a case that on the initial withdrawal of the belt webbing, the cross-pieces traveled through by the guide pin in the peripheral direction are arranged in an adapted position, such that the cross-pieces are aligned obliquely to the peripheral direction. At their inner end, the cross-pieces have a flattened introduction surface for the guiding in of the guide pin between the cross-pieces, so that the guide pin of the locking lever, following the quick initial rotation of the wobble plate, also does not directly impact the cross-pieces. 
         [0022]    Insofar as the switching lever for the ELR-ALR switchover is not engaged with the toothing formed on the housing cap during the ELR switching state, an exemplary embodiment of the invention provides that the outer periphery of the bearing ring of the wobble plate forms a third cam for controlling the guide pin of the switching lever during the ELR switching state of the switching lever. Here to better guide the guide pin of the switching lever during the ELR switching state, it is proposed that the contact surface of the guide pin, which is directed towards the bearing ring of the wobble plate, is constructed with a curvature corresponding to the outer curvature of the bearing ring. 
         [0023]    For the radial deflection of the switching lever, which is necessary in the switchover from ELR to ALR operation, it is proposed that between the bearing ring and the strip, a radial cross-piece is arranged to radially control the guide pin of the switching lever out of its cam, which is formed by the bearing ring, so that is abuts against the inner cam of the strip during the ALR switching state, which is reached by the guide pin at the end of the belt webbing withdrawal. In a peripheral distance from the cross-piece, the inner cam has a section, directed radially inwards to the bearing ring, for the controlling of the guide pin from the inner cam of the strip to the cam on the bearing ring. 
         [0024]    The circumstance can also occur that in the case of a very rapid belt webbing withdrawal, on reaching the ELR/ALR switchover point, the guide pin situated on the switching lever breaks off, so that a switching back to the ELR operation is not possible due to a faulty return of the switching lever on the inner cam of the strip. In order to nevertheless make possible a switching back in such a case, provision can be made that the locking lever and switching lever are arranged in different planes, staggered in the axial direction of the control disc, and the locking lever has an attachment extending into the movement plane of the switching lever and carrying the guide pin, wherein the attachment cooperates with the switching lever in at least one switching position of the locking lever. When the locking lever, on rolling up of the belt webbing such that the belt webbing is sufficiently wound, changes from the outer cam into the inner cam, the locking lever presses the switching lever back via its attachment, even in the absence of the guide pin in its abutment characterizing the ELR operation on the third cam on the periphery of the bearing ring. For structural reasons, provision can be made that for the production of the necessary motion clearance for the switching pin, the inertial mass extends in its axial height over both movement planes of the locking lever and switching lever, and has a cutout to receive the switching lever, wherein the cutout is arranged in the movement plane of the switching lever. As such, a space-saving compact construction of the components which are to be arranged on the control disc can be achieved. 
         [0025]    According to an exemplary embodiment of the invention, at least one locking tooth is arranged on the locking lever, and in its cutoff position, the locking tooth engages into a peripheral recess formed on the belt shaft for the secure connection of belt shaft and control disc. Thus, in the cutoff position of the locking lever, the locking lever non-rotatably locks the control disc or its platform with the belt shaft, so that during a safety function, relative movement of the control disc and belt shaft with respect to each other, which would initiate the blocking of the belt retractor, is ruled out. 
         [0026]    To improve the mounting of the belt retractor, an exemplary embodiment of the invention provides that the control disc with the functional parts of the inertial mass, locking lever, and switching lever mounted thereon, as well as the wobble plate, is able to be inserted into the housing or covering cap, formed in a cup shape, for the formation of a pre-mounted assembly, and is able to be secured therein. In this respect, in the final mounting of the belt retractor, the belt shaft with a shaft extension formed thereon only needs to be connected to the pre-mounted assembly. 
         [0027]    In detail, an exemplary embodiment of the invention provides that the control disc and wobble plate are arranged together on an adapter piece, and the adapter piece is able to be secured in the housing cap on one hand, and on an extension of the belt shaft on the other hand, thereby forming the bearing of the belt shaft in the housing cap, wherein the adapter piece is respectively engageable with the housing cap and shaft extension. Furthermore, the adapter piece may be secured with a form fit on the shaft extension. 
         [0028]    The pre-mounting of the belt retractor according to the invention is then facilitated, insofar as an exemplary embodiment provides that the adapter piece carries the control disc on an encircling flange and thereby forms the pre-mounted assembly which is to be engaged with the housing cap, wherein the shaft extension can be fixedly inserted into the adapter piece which is secured on the housing cap. 
         [0029]    Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    Example embodiments of the invention are shown in the drawings, which are described below. The drawings show: 
           [0031]      FIG. 1  is an exploded fragmentary view of a system side of a self-locking belt retractor with belt-webbing-sensitive and vehicle-sensitive control systems, 
           [0032]      FIG. 2  is a fragmentary view of  FIG. 1  according to another perspective, 
           [0033]      FIG. 3  is an enlarged top view of the system side of the belt retractor with assembled individual parts, 
           [0034]      FIG. 4  is a perspective view of a control disc with functional elements arranged thereon during activation of the vehicle-sensitive and of the belt-webbing-sensitive control system, 
           [0035]      FIG. 5  is a perspective view  FIG. 4  wherein the control systems are in a cutoff state, 
           [0036]      FIG. 6  is a perspective view of the control disc of  FIGS. 4 and 5  according to another embodiment of the present invention with activation of the vehicle-sensitive and of the belt-webbing-sensitive control system in ELR operation, 
           [0037]      FIG. 7  is a perspective view of  FIG. 6  in ALR operation, 
           [0038]      FIG. 8  is a perspective view of  FIGS. 6 and 7  wherein the vehicle-sensitive and the belt-webbing-sensitive control system are cutoff, 
           [0039]      FIG. 9  is a perspective view of a cutout of a housing cap, 
           [0040]      FIG. 10  is an enlarged perspective view of a wobble plate with cams formed thereon, 
           [0041]      FIG. 11  is a perspective view of the wobble plate according to  FIG. 10  with movement paths for guide pins of a locking lever and a switching lever formed on the cams, 
           [0042]      FIG. 12  is a perspective view of the wobble plate of  FIG. 10  according to another embodiment of the present invention, 
           [0043]      FIG. 13  is a perspective view of the control disc placed in combination with the wobble plate, 
           [0044]      FIG. 14  is a perspective view of the control disc according to  FIG. 7 , the control disc including associated cams of the wobble plate in ALR operation, and 
           [0045]      FIG. 15  is a perspective view of the control disc according to  FIG. 8 , the control disc including associated cams of the wobble plate during cutoff of the vehicle-sensitive and of the belt-webbing-sensitive control system. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0046]    As can be seen firstly from  FIGS. 1 and 2 , a system side of a self-locking belt retractor is shown comprising a belt shaft  10  with a shaft extension  11  projecting therefrom along a shaft axis defined by the belt shaft  10 , wherein the belt shaft  10  serves as mounting means and as drive means for the system parts connected to the belt shaft  10 . A blocking catch  12  is mounted on the belt shaft  10  and is able to be swung out radially for engagement into a toothed blocking (not illustrated) fixed to the housing, wherein the blocking catch  12  has a guide pin  12   a  projecting in the shaft axis. The guide pin  12   a  engages into a link formed on a control disc  13 , such that the control disc  13  rotates respectively together with the belt shaft  10 . In the case of a response by a vehicle-sensitive and/or belt-webbing-sensitive control system which is to be described below, the control disc  13  is blocked from further rotary movement, so that relative rotation is produced between the stationary control disc  13  and the rotating belt shaft  10 , wherein this relative rotation is converted by the guide pin  12   a , which is guided in the control disc  13 , into the radial deflection of the blocking catch  12 . This radial blocking principle is known to those of ordinary skill in the art and will therefore not be described in greater detail. 
         [0047]    An essential functional component of the belt retractor is the control disc, designated by  13 , which consists of a platform  14  and a ring  16  externally surrounding the platform  14 . On the platform  14  of the control disc  13 , an inertial mass  15  is swivellably mounted swivellably thereon, which forms the belt-webbing-sensitive control system described below. 
         [0048]    A wobble plate  17  arranged adjacent to the control disc  13  and cooperating functionally therewith, has cams  18  on its underside facing the control disc  13 . The wobble plate  17  includes a recess having an inner toothing  23  for slidably engaging an externally toothed extension  22  of the platform  14 , so that when the control disc  13  is rotating with the belt shaft  10 , the control disc  13  drives the wobble plate  17  and entrains it in a rotating manner. 
         [0049]    The system side of the belt retractor is surrounded and covered by a housing cap  19  having an internal toothing  20  fixed to the cap  19  on its inner side. 
         [0050]    The functional parts of the system side of the belt retractor described above are held together by an adapter piece  21  which carries the platform  14  of the control disc  13  by a projecting flange  35 . At its end facing the housing cap  19 , the adapter piece  21  has a detent groove  36  which can be inserted into a corresponding detent configuration on the inner side of the housing cap  19  so that the adapter piece  21  is able to be engaged thereon. As the control disc  13  and the wobble plate  17  are arranged on the adapter piece  21 , a pre-mounted assembly is produced by way of the control disc  13  and the wobble plate  17  being able to be secured with the associated functional parts (discussed below) on the housing cap  19  via the adapter piece  21 . 
         [0051]    The shaft extension  11  of the belt shaft  10  engages into the adapter piece  21  with a form-fitting connection, wherein the adapter piece  21  is able to be engaged with the shaft extension  11  of the belt shaft  10  via a detent window  37  during the final mounting of the belt retractor. 
         [0052]    As can be further seen from  FIG. 2 , the ring  16  has both an outer toothing  25  and an inner toothing  26 . Outside the control disc  13 , a vehicle sensor  24  is secured on the inner side of the housing cap  19 , wherein a sensor lever of the vehicle sensor  24  comes into engagement with the outer toothing  25  of the ring  16  of the control disc  13  based on corresponding vehicle accelerations or vehicle decelerations as understood to those of ordinary of skill in the art, and thereby blocks the ring  16  from further rotary movement. 
         [0053]    On the platform  14  of the control disc  13 , a locking lever  27  is swivellably mounted between an activation position and a cutoff or disabling position. In the activation position, the locking lever  27  is in engagement with the inner toothing  26  of the ring  16 . As such, the externally toothed ring  16  is therefore connected to the platform  14  via the locking lever  27 , so that in light of conventional control discs, a control disc  13  is formed which is capable of functioning. When the sensor lever of the vehicle sensor  24  engages into the outer toothing  25  of the control disc  13  during this activation position, the control disc  13  is stopped from further rotary movement and the blocking movement of the blocking catch  12  is brought about. On the other hand, when the locking lever  27  is controlled such that it is not in engagement with the inner toothing  26  of the ring  16 , and is in fact in engagement with the sensor lever of the vehicle sensor  24  via the outer toothing  25  of the ring  16 , the ring  16  remains at a standstill, but the platform  14 , which is connected to the belt shaft  10 , continues to rotate, so that the necessary relative rotation is not brought about; thus, the vehicle-sensitive control system is cut off. 
         [0054]    As can be further seen from  FIG. 4 , the belt-webbing-sensitive control system is realized through the arrangement of the inertial mass  15  mounted movably on the platform  14 . During normal rotations of the shaft  10 , the inertial mass  15  lies within the contour of the platform  14 , so that the platform  14  or the control disc  13  rotates together with the belt shaft  10 . If a rapid belt withdrawal movement occurs, then the inertial mass  15  remains behind the rotating platform  14  and is thereby deflected. With this deflection, a blocking tooth  40  formed on the inertial mass  15  engages into the toothing  20  of the housing cap  19 , so that further rotary movement of the control disc  13  is stopped and the relative rotation between the control disc  13  and belt shaft  10  occurs, thereby bringing about the blocking of the belt retractor. 
         [0055]    It can be seen from  FIG. 5  that the locking lever  27  is arranged on the platform  14  such that in its inwardly swiveled position, wherein the locking lever  27  is not in engagement with the inner toothing  26 , it abuts against the inertial mass  15  which is mounted so as to be swivellably movable, and thereby secures the latter against swivelling movement. As the inertial mass  15  is therefore secured by the locking lever  27 , the function of the inertial mass  15  described above can no longer occur in the case of rapid belt webbing withdrawal. In this respect, it can be seen that through the single switching movement of the locking lever  27 , both the vehicle-sensitive control system and the belt-webbing-sensitive control system is cut off or functionally disabled. 
         [0056]    It can also be seen from  FIG. 5  that as an additional security measure for the disabling of the control systems, a locking tooth  33  projecting in the direction of the shaft extension  11  of the belt shaft  10  is formed on the lever  27 . In the cutoff position of the locking lever  27  ( FIG. 5 ), the locking tooth  33  comes into engagement with a peripheral recess  34  provided on the periphery of the shaft extension  11 , so that in this engagement position the belt shaft  10  and the control disc  13  are non-rotatably locked with each other. Therefore, relative rotation between the control disc  13  and the belt shaft  10 , which is necessary for the blocking of the belt retractor, is prevented. 
         [0057]    The belt retractor may also have an ALR/ELR switchover function. For this function, a separate switching lever  28  is mounted on the platform  14 . In the ALR switching position, in which the control disc  13  is secured against further rotation, the switching lever is to be swiveled outwards to engage with the toothing  20  of the housing cap  19 . 
         [0058]    In order to carry out the corresponding swivelling and switching movements of the locking lever  27  and switching lever  28 , the two levers have a guide pin,  27   a  and  28   a , respectively, wherein these guide pins  27   a ,  28   a  are guided in the cams  18  of the wobble plate  17 , so that controlling the movements of the locking lever  27  and switching lever  28  takes place via the rotation of the wobble plate  17 . 
         [0059]      FIGS. 6-8  illustrate an alternative embodiment of the control disc  13  with the functional parts arranged thereon. 
         [0060]    Insofar as the control disc  13  illustrated in  FIG. 6  in its functional position during activation of both the vehicle-sensitive and the belt-webbing-sensitive control system, i.e. in the ELR switching state, corresponds to the embodiment illustrated in  FIG. 4  and already described, those features are denoted by identical reference characters and will not be described in detail below. The embodiment illustrated in  FIG. 6  shows the locking lever  27  in the deflected position and in engagement with the inner toothing  26  of the ring  16 . The switching lever  28  is situated in its swiveled-in position, wherein the switching lever  28  engages with an inner spring arm  50  into a recess  51  formed on the extension  22  of the platform  14  of the control disc  13 . In the illustrated embodiment, the locking lever  27  and switching lever  28  are arranged in different planes staggered in an axial direction of the control disc  13 . The locking lever  27  has an attachment  52  extending into the plane of movement of the switching lever  28  and carrying the guide pin  27   a . As will be described in greater detail below, the attachment  52  cooperates with the switching lever  28  in a switching position of the locking lever  27 . At the same time, the inertial mass  15  axially extends along its height over both movement planes of the locking lever  27  and switching lever  28 . In addition, the inertial mass  15  has a cutout  53 , arranged in the movement plane of the switching lever  28 , to receive the switching lever  28  so that the switching lever  28  respectively follows the control movements of the inertial mass  15 . With this step, a space-saving construction of the control disc  13  is achieved with the functional parts formed thereon. The arrangement of the attachment  52  lying in the movement plane of the switching lever  28  on the locking lever  27  helps bring about the disabling of the belt-webbing-sensitive control system. In particular, for the case where a cutoff of the guide pin  28   a  situated on the switching lever  28  were to occur due to a very rapid belt webbing withdrawal reaching the ELR/ALR switchover point, the foregoing arrangement brings the switching lever  28  and hence the belt-webbing-sensitive control system in its cutoff position via the cutoff movement of the locking lever  27  by means of the associated cam, and at the same time, via the abutment of the attachment  52  on the switching lever  28 , in which case a blocking of the belt shaft is no longer possible. 
         [0061]    In  FIG. 7 , the control disc  13  of  FIG. 6  is illustrated in the ALR switching state. As can be seen, the switching lever  28  is swiveled radially outwards, wherein its spring arm  50  has emerged out of the recess  51  and lies with a corresponding pre-stressed tension on the extension  22  of the platform  14 . If a controlling back of the switching lever  28  occurs on the switchover from the ALR switching state into the ELR switching state, the spring arm  50  engages again into the recess  51 , so that the ELR switching state is defined. 
         [0062]    In  FIG. 8 , the cutoff of both the vehicle-sensitive and the belt-webbing-sensitive control system is illustrated, in which the locking lever  27  is guided inwards out of engagement with the inner toothing  26  of the ring  16 . In so doing, the locking lever  27  at the same time secures the inertial mass  15 , so that the belt-webbing-sensitive control system cannot respond. At the same time, the switching lever  28  is in a swiveled-in position, so that no blocking of the belt shaft can be brought about. 
         [0063]    As can be seen from  FIG. 9 , an eccentric bearing  29  for the wobble plate  17  is formed on the inner side of the housing cap  19 , so that the rotary drive of the wobble plate  17 , brought about via the engagement of the inner toothing  23  of the wobble plate  17  with the externally toothed extension  22  of the control disc  13  or the platform  14 , is able to be converted at the same time into an eccentric-radial displacement of the wobble plate  17 . 
         [0064]    In  FIGS. 10 and 11 , the construction of the wobble plate  17  is shown, wherein the wobble plate  17  is arranged to control the switching movements of the locking lever  27  and switching lever  28 . As can be seen firstly from  FIG. 10 , the wobble plate  17  has a strip  54  extending over its periphery and projecting axially into the plane of the guide pins  27   a ,  28   a  of the locking lever  27  and switching lever  28 , respectively. The wobble plate  17  also has a bearing ring  55 , projecting parallel to the strip  54 , for the bearing of the wobble plate  17 . The strip  54  is arranged with a radial distance to both the bearing ring  55  and the outer periphery of the wobble plate  17 . Moreover, an inner cam  30  and an outer cam  31  respectively formed on the inner and outer side of the strip  54  is provided for the guide pin  27   a  of the locking lever  27 , and at least one opening  32  is provided as a radial transition section for the passage of the guide pin  27   a  between the inner cam  30  and the outer cam  31 . 
         [0065]    On their running paths for the guide pins  27   a ,  28   a  of the locking lever  27  and switching lever  28 , the cams  30 ,  31  have an undulating contour for equalizing the movements of the wobble plate with respect to the guide pins  27   a ,  28   a  of the locking lever  27  and switching lever  28 , revolving with the control disc  13 . Owing to the strip  54 , extending over the entire periphery, with cams  30 ,  31 , the guide pin  27   a  of the locking lever  27  is guided during the entire rolling and unrolling movement of the belt shaft  10  on the cams  30 ,  31 . The wobble plate  17  is designed so that a full revolution of the wobble plate  17  corresponds to the revolutions of the belt shaft  10  carried out during the unwinding or winding of the belt webbing between the complete winding state and the complete unwinding state. Depending on the length of the belt webbing wound on the belt shaft  10  of the belt retractor, the belt shaft  10  can carry out 14 to 16 revolutions, for example, with a complete revolution of the wobble plate  17 . 
         [0066]    To control the switching lever  28 , the wobble plate  17  additionally has a third cam  56 , which is formed by the outer periphery of the bearing ring  55  of the wobble plate  17 . In addition, at the switchover point from the ELR to the ALR switching state of the belt retractor with almost complete belt webbing withdrawal, a radial cross-piece  57  is arranged between the bearing ring  55  and the strip  54  for the radial guidance of the guide pin  28   a  of the switching lever  28  out of its cam  56  for the ELR switching state and up to abutment against the inner cam  30  of the strip  54  during the ALR state, wherein with the unrolling movement of the belt webbing from the belt shaft, the guide pin  28   a  reaches the cross-piece  57  at the end of the belt webbing withdrawal and is re-routed by the cross-piece  57  into its swiveled-out position. In addition, the strip  54  has a section  58  in the region of its inner cam  30 , wherein the section  58  is directed radially inwards to the bearing ring  55 . In this manner, after a rolling movement of the belt webbing, (i.e., corresponding to the path of the guide pin  28   a  of the switching lever  28  from the cross-piece  57  along the inner cam  30 ), onto the belt shaft of the guide pin  28   a , a re-routing takes place from the inner cam  30  to the cam  56  on the bearing ring  55 , whereby the ELR switching state is reproduced. 
         [0067]    In  FIG. 11 , the path of the guide pin  27   a  for controlling the locking lever  27 , and the path of the guide pin  28   a  for controlling the switching lever  28 , is shown for the control contour illustrated in  FIG. 10 . Here, the guide pin  27   a  is illustrated in the position with a fully wound belt webbing; the illustration in dashed lines makes it clear that in particular embodiments a greater amount of belt webbing can be wound on the belt shaft  10 . As can be seen from the illustration of the path line  59  for the movement of the guide pin  27   a , at the start of the unwinding of the belt webbing, the guide pin  27   a  firstly follows the inner cam  30  up to the opening  32 , by which the guide pin  27   a  is deflected radially outwards. Then, on further unwinding of the belt webbing, the guide pin  27   a  follows the outer cam  31 , in which the locking lever  27  is guided in engagement with the toothing  26  of the ring  16 , and hence produces the function of the control disc  13 . Accordingly, on winding of the belt webbing, the control pin  27  follows the path line  59  up to its initial position. 
         [0068]    Correspondingly, for the movement of the guide pin  28   a  of the switching lever  28 , the path line  60  is similarly illustrated in  FIG. 11 , and it can be seen here that the guide pin  28   a , firstly up to reaching the switchover point defined by the cross-piece  57 , is guided on the cam  56  of the bearing ring  55 , whereby the swiveled-in position of the switching lever  28  is defined. When the belt webbing is (almost) completely unwound from the belt shaft and therefore the ALR switching state is to be brought about, the guide pin  28   a  is deflected radially outwards via the cross-piece  57 . If after a certain extent of winding of the belt webbing onto the belt shaft  10 , a switching over is to take place again from the ALR switching state to the ELR switching state, then firstly the guide pin  28   a  follows the inner cam  30 , during the return rotation of the belt shaft  10 , until the guide pin  28   a  reaches the section  58  arranged in the region of the opening  32 , via which the guide pin  28   a  is guided back in abutment against the bearing ring  55 , and hence into the path of the cam  56 , in which the switching lever  28  is not engaged with the toothing  20  of the housing cap  19 . 
         [0069]    In  FIG. 12 , another embodiment of the wobble plate  17  is illustrated. Here, the strip  54  with the cams  30 ,  31  formed thereon extends only over a partial region of the periphery of the wobble plate  17 , wherein the partial region is traveled through by the guide pin  27   a  of the locking lever  27  after initial belt webbing withdrawal, wherein the guide pin  27   a  is in a position such that it is guided outwards to engage with the inner toothing  26  of the ring  16 . In the other, remaining peripheral region, radially outwardly directed cross-pieces  60  are arranged on the wobble plate  17  such that with corresponding control movements, the guide pin  27   a  of the locking lever  27  can enter between the cross-pieces  61 . Insofar as the control pin  27   a , with initial belt webbing withdrawal, travels in the peripheral direction through a curved line, the cross-pieces  61  are arranged with an adapted position, aligned obliquely to the peripheral direction, and have at their inner end a flattened introduction surface  62  for the guiding of the guide pin  27   a  into the spaces respectively existing between the cross-pieces  61 . As such, in the case of high initial accelerations of a belt webbing withdrawal, the guide pin  27   a  does not strike against the cam  30  formed in this region (i.e., according to the embodiment described with respect to  FIGS. 10 and 11 ), and does not break off under these circumstances. Rather, the guide pin  27   a  can enter radially outwards into the spaces existing between the cross-pieces  61  and in so doing, the guide pin  27   a  is not subject to any stress. Since in such a case of a high acceleration of belt webbing withdrawal, the belt-webbing-sensitive control system would at the same time respond with a blocking of the belt shaft  10 , further rotation of the belt shaft  10  would be prevented, so that the guide pin  27   a  no longer carries out a movement in the peripheral direction of the wobble plate  17 . If the belt webbing is slackened to release this blocking state, the guiding pin  27   a  slips out of the region of the cross-pieces  61  again, and can then take its path up to the opening  32  with a correspondingly slower withdrawal movement. 
         [0070]    In  FIGS. 14 and 15 , respectively, the control disc  13  is again illustrated with the levers  27 ,  28  arranged thereon and in cooperation with the cams  30 ,  31 ,  56  of the wobble plate  17 . Here,  FIG. 14  in turn shows the ALR switching state, in which the switching lever  28  is in its guided-out position in engagement with the toothing  20  of the housing cap  19 , in which the guide pin  28   a  lies against the inner cam  30  of the strip  54 . In this position, the locking lever  27  is guided into the outer toothing  26  of the ring  16 , and in this respect, the guide pin  27   a  lies against the outer cam  31 . In this respect, therefore, an immediate readiness for blocking exists in the case of a belt webbing withdrawal, as is provided for the ALR operation. 
         [0071]      FIG. 15  once again shows the state in which both the vehicle-sensitive and the belt-webbing-sensitive control system is cut off. In this respect, the guide pin  27   a  of the locking lever  27  is guided on the inner cam  30 , so that the locking lever  27  is not in engagement with the outer toothing  27  of the ring  16 , and so that the ring  16  rotates on access of the vehicle sensor and no blocking is initiated. At the same time, the locking lever  27  lies against the inertial mass  15  and therefore blocks the response of the belt-webbing-sensitive control system. The switching lever  28  lies in its inner position with abutment of the guide pin  28   a  against the control cam  56 , which, however, is without functional significance for the cutoff of the belt-webbing-sensitive and vehicle-sensitive control system. 
         [0072]    The features of the subject matter of the present invention, as disclosed in the above description, the claims, the abstract, and the drawings, can be essential individually and also in any desired combinations with each other for the realization of the invention in its various embodiments. 
         [0073]    As a person skilled in the art will readily appreciate, the above description is meant as an illustration of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from spirit of this invention, as defined in the following claims.

Technology Category: 7