Patent Abstract:
A self-locking belt retractor in particular for motor vehicles with a vehicle-sensitive and a webbing-sensitive control system for the blocking device of the belt retractor having an operatable toothed lock washer in a cased gearing.

Full Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to German Patent Application No. 10 2008 025 431.2, filed May 27, 2008, and PCT/EP2009/003591, filed May 20, 2009. 
     FIELD OF THE INVENTION 
     The invention concerns a self-locking belt retractor in particular for motor vehicles with a vehicle-sensitive and a webbing-sensitive control system for the blocking (locking) device of the belt retractor having an operatable toothed lock washer in a cased gearing, whereby the control system includes a cam disc rotating with the belt shaft, coupled to the toothed lock washer and inertially formed to form the webbing-sensitive controller with external gearing for the engagement of a sensor lever of a vehicle sensor arranged on the belt retractor, whereby at least one catch lever is provided controlled by the rotation of the belt shaft and rotatable between an engaged and a disengaged position for switching the vehicle sensor off in a function range in which almost the whole of the seatbelt is retracted onto the belt shaft, and whereby a device is provided for switching the webbing-sensitive controller off as well in the above-mentioned function range of the belt retractor. 
     BACKGROUND OF THE INVENTION 
     A belt retractor with the above-mentioned characteristics is described in DE 103 60 032 A1. To prevent the blocking mechanism of the belt retractor triggering when the seat belt is retracted under the effect of the roller spring or braked abruptly at the end of the retraction path after the passenger has unfastened the seat belt, the familiar belt retractor already provides for a cutoff of both the webbing-sensitive and of the vehicle-sensitive control systems, so that an unwanted blocking of the belt shaft at the end of the seat belt&#39;s retraction path is prevented. 
     For this purposes the familiar belt retractor has a locking disc on the belt shaft and rotating with the belt shaft that controls a stationary catch lever on bearings rotatable relative to the housing by means of a guide curve formed on it that in a function range in which almost the whole of the seat belt is rolled onto the belt shaft as a direct effect on the sensor lever of the vehicle sensor that works together with the cam disc and immobilizes this and in this way switches the vehicle-sensitive control system off. Insofar as the webbing-sensitive control system is realized through a cam disc formed with appropriate inertia, to switch the webbing-sensitive control system off there is an additional lock on the belt shaft, which is coupled for its operations via a guide gate to the catch lever for switching the vehicle sensor off and engages with the cam disc in its blocking position brought about by the locking position of the catch lever and locks the cam disc torque-proof with the belt shaft. 
     The familiar belt retractor has the disadvantage that different levers are provided for switching off both the vehicle-sensitive and the webbing-sensitive control systems, which makes the structure of the belt retractor complicated and the construction cost is correspondingly high. In addition, the two control systems can only be switched off consecutively, because initially the operation of the catch lever for the vehicle sensor is a prerequisite for the control of the lock for the webbing-sensitive control system. Because several control procedures are necessary, a corresponding fault dependency cannot be ruled out. 
     In addition, it is already known from DE 100 27 134 A1 that with a belt retractor with an inert cam disc on the shaft extension the vehicle sensor is to be attached to the inside of a cover spanning the control system and the sensor lever of the vehicle sensor is to engage with the external gearing of the cam disc to control it. 
     SUMMARY OF THE INVENTION 
     The invention is based on the problem of simplifying a self-locking belt retractor with the characteristics in accordance with the previously mentioned type with regard to switching off both the vehicle-sensitive and the webbing-sensitive control systems and to improve the security of the switching off function. 
     The solution of this problem results including advantageous embodiments and further formations of the invention from the contents of the patent claims, which follow this description. 
     The invention provides in detail that a cap spanning the control system and fixed to the belt retractor housing has a catch lever controlled by a counter transmission mounted on it that switches off with a single switching action both the vehicle sensor mounted on the cap and an inertia mass mounted on the cam disc that be rotated from an inertia control position into a blocking position for the cam disc. Insofar as, in contrast to the state of the art, the inertia mass of the cam disc is formed by an inertia mass mounted movably on the cam disc, this results in the advantageous function of switching both the vehicle sensor and the inertia mass off at the same time through a single catch lever. This means that the invention has the advantage that only a single component and a single switching action is necessary to switch both control systems off together. Because this catch lever is also mounted on the cap in the same way as the vehicle sensor, the cap is the bearer for several components that are necessary for the function of the belt retractor, so that the design of the belt retractor is simplified on the whole as well. 
     According to an embodiment of the invention it is planned for a connector ring having both external and internal gearing to be mounted rotatable on the cap, whereby the inertia mass of the cam disc is controlled in its blocking position for the cam disc in engagement with the internal gearing of the connector ring and the catch lever can be reversed by the counter transmission between an engagement position with the external gearing of the connector ring and a release position. Insofar therefore that the inertia mass requires a non-rotatable fixed connector ring as thrust bearing for its function as a webbing-sensitive controller, the switching on or off of the webbing-sensitive control system takes place through the catch lever either immobilizing the connector ring or letting it rotate. 
     With regard to the switching on or off of the vehicle sensor according to an embodiment of the invention it is planned for the catch lever to be mounted on the cap in such a way that in its switching off position for the vehicle sensor the catch lever immobilizes the sensor lever of the vehicle sensor. If the sensor lever of the vehicle sensor is immobilized by the catch lever, it cannot engage with the external gearing of the cam disc, so that the vehicle-sensitive control system is switched off. 
     In particular in accordance with an embodiment of the invention it is therefore planned that the catch lever in its switching off position for the webbing-sensitive and the vehicle-sensitive control system is controlled outside engagement with the external gearing of the connector ring and in this position also immobilizes the sensor lever of the vehicle sensor. 
     According to an embodiment of the invention, the catch lever is designed as a rocker mounted on the outside of the cap and moved in a reciprocating fashion by the counter transmission that with a function range bent at a right angle reaches through the cap in a recess and grips the external gearing of the connector ring and the sensor lever of the vehicle sensor. This enables a compact design of the belt retractor. 
     According to an embodiment of the invention it is planned that the counter transmission consists in a familiar manner of a number of interlocking cogs coupled to the belt shaft on which the trip cams are mounted that cause the respective switching of the catch lever. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings show an embodiment of the invention that is described below. The following is shown: 
         FIGS. 1   a , and  1   b  show the webbing-sensitive and the vehicle-sensitive control system of a self-locking belt retractor including the device for switching this on and off in a schematic representation with the sensor technology switched on, 
         FIGS. 2   a , and  2   b  are similar to  FIGS. 1   a  and  1   b  showing the sensor system switched off, 
         FIG. 3  is a top view of the cap of the belt retractor with the counter transmission mounted thereon and the catch lever controlled by this, and 
         FIG. 4  shows the system side of the belt retractor in accordance with  FIGS. 1 to 3  in cross-section. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1   a  and  1   b  each show the system side of a belt retractor in a view from the belt shaft to the inside of a cap  10  as the bearer of function parts of the belt retractor. On the inside of the cap  10  an axial gearing  11  for immobilizing a vehicle sensor  12  by means of an adapter  34  that can be seen in  FIG. 4  is shown in different positions. The vehicle sensor  12  has a sensor lever  13  that is controlled as part of the webbing-sensitive and of the vehicle-sensitive control systems when the vehicle sensor  12  is triggered in engagement with the external gearing  33  of a cam disc not shown in  FIGS. 1   a  and  1   b . This cam disc  32  can be seen more clearly in  FIG. 4 . 
     The webbing-sensitive control system of the belt retractor is formed by an inertia mass  14  having a blocking tooth  16  at an outer end and mounted on cam disc  32  rotating around a bearing  15  and projecting over the plane of cam disc  32  into the plane enclosed by the cap  10 . 
     A rotating connector ring  17  having an internal gearing  18  and an external gearing  19  is mounted in the cap  10 . The internal gearing  18  is designed so that the inertia mass  14  can engage with the internal gearing  18  with its blocking tooth  16  in its one function position that is still to be described. 
     A catch lever  20  is mounted on the cap  10  in such way that in its two function positions that still have to be described. The catch lever  20  engages or disengages with the external gearing  19  of the connector ring  17  by means of the stopper  22  and in this way immobilizes or releases the connector ring  17 . In addition, the catch lever  20  has a cam  21  that is mounted in such a way that in its corresponding function position the catch lever  20  immobilizes the sensor lever  13  via the surface of cam  21  at the sensor lever  13  of the vehicle sensor  12  in such a way that this cannot engage with the external gearing  33  of the cam disc  32  ( FIG. 4 ). 
       FIGS. 1   a  and  1   b  show the respective engagement position for both the webbing-sensitive and the vehicle-sensitive control system. In this engagement position, the catch lever  20  with its stopper  22  engages with the external gearing  19  of the connector ring  17  and in this way immobilizes it. If there is a corresponding rotational acceleration in this engagement position of the cam disc  32  coupled with the belt shaft  29 , because of the moment of inertia the inertia mass  14  is deflected and engages with its blocking tooth  16  in the internal gearing  18  of the connector ring  17  which is immobilized unrotatably through the catch lever  20 . In this way the cam disc  32  is stopped in its rotational movement and this results in a relative rotation between cam disc  32  and belt shaft  29 , and this relative movement is converted in way that is familiar from generic belt retractors into a deflection of the toothed lock washer  30  ( FIG. 4 ) into a gearing fixed in a housing and thus into a blocking of the rotational movement of belt shaft  29 . 
     At the same time according to  FIG. 1   a , the cam  21  of the catch lever  20  is outside the range of movement of the sensor lever  13  of the vehicle sensor  12 , so that with corresponding vehicle decelerations or vehicle accelerations, the vehicle sensor  12  can control the sensor lever  13  in engagement with the external gearing  33  of the cam disc  32 . In this way, the cam disc  32  is also stopped in its rotational movement, whereby the control of the toothed lock washer  30  is effected. 
       FIGS. 2   a  and  2   b  show correspondingly the simultaneous disconnection of the webbing-sensitive and of the vehicle-sensitive control system through the reversal of the catch lever  20  in its disconnection position. As shown in  FIG. 2   b , the catch lever  20  with its stopper  22  is disengaged with the external gearing  19  of the connector ring  17 , so that the connector ring  17  can rotate. If the blocking tooth  16  of the inertia mass  14  engages with the internal gearing  18  of the connector ring  17 , the thus deflected inertia mass  14  does not find a thrust bearing in the rotating connector ring  17 , so that connector ring  17 , inertia mass  14  and cam disc  32  continue to rotate together with belt shaft  29 . Because of a lack of a relative movement between cam disc  32  and belt shaft  29  a deflection of toothed lock washer  30  and thus a blocking of belt shaft  29  does not take place. The webbing-sensitive control system is thus disconnected. 
     According to  FIG. 1   a  in this disconnected position of the catch lever  20  its cam  21  immobilizes the sensor lever  13  in a position in which the sensor lever  13  cannot engage with the external gearing  33  of the cam disc  32 . Insofar, with corresponding vehicle decelerations or vehicle accelerations, a blocking of the rotational movement of the cam disc  32  and thus its relative movement to the belt shaft  29  does not take place. The vehicle-sensitive control system is disconnected. 
     The switching in a reciprocating fashion of the catch lever  20  between the function positions of the catch lever  20  described above in accordance with  FIGS. 1   a  and  1   b  and  FIGS. 2   a  and  2   b  is controlled via a counter transmission mounted on the outside the cap  10 . For this purpose the belt shaft  29 , as can be seen in  FIG. 4 , passes through the cap  10  with a shaft extension  35 , on which is mounted a shaft cog  23  that rotates with the belt shaft  29 . The shaft cog  23  is in constant meshed engagement with a rocker cog  24  mounted on the catch lever  20 , which is designed as rocker than can be moved in a reciprocating fashion, the said rocker cog  24  being in meshed engagement with another rocker cog  25  fixed rotatably on the cap  10 . Trip cams  26  are mounted on all three cogs  23 ,  24 , and  25  that on the given protraction or retraction statuses of the webbing come into contract with each other in dependence on the rotation movements of the belt shaft  29  so that this enables the catch lever  20 , which is designed as a rocker, can be switched between its function positions. This switching principle is sufficiently known from the state of the art. The catch lever  20  mounted in the form of a rocker on the outside of the cap  10  passes through the cap  10  in an assigned recess  28  with an offset section  27  and forms the stopper  22  and the cam  21  at its offset section  27  that projects into the level enclosed by the cap  10 . 
     The features of the object of these documents disclosed in the above description, the patent claims, the summary and the drawings can be essential for the realization of the invention in its various embodiments either individually and in any combinations with one another. 
     While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.

Technology Classification (CPC): 1