Patent Publication Number: US-9840859-B2

Title: Sliding door for motor vehicles

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a motor vehicle sliding door which can be moved back and forth by means of a sliding movement between an open and a closed position, wherein, in order to lock the sliding door in the open position thereof, a mechanical door stop in the form of a locking latch which has a receiving region for a catch element of the sliding door is provided, and wherein the locking latch can be released by means of a motorized actuation device, whereby the catch element is released. 
     BACKGROUND OF THE INVENTION 
     So-called passive systems by means of which the sliding of a motor vehicle door is secured in the open position thereof after overcoming a mechanical resistance in order to prevent undesirable closure of the sliding door have already been known for a long time. To this end, there is used a mechanical door stop in the form of a locking latch which retains the door in the open position thereof. When the sliding door is intended to be closed again, the operator has to overcome the mechanical resistance in the opposite direction. For example, resiliently loaded stoppers are used as the resistance. 
     This known passive system is often uncomfortable for the operator since the resistance which is intended to be overcome requires a relatively large application of force. Therefore, there has already been developed a so-called active door stop (EP 1617031 A2 and EP 1717392 A2), in which the locking latch is released by means of an electromotive actuation device so that the sliding door can be readily pushed into the secured position thereof and back again. 
     Although this active system is comfortable to handle, it has the disadvantage that, for example, in the event of a power failure or a defect in the actuation device between the drive motor and locking latch, the sliding door is blocked in the open position thereof. An interruption of the blocking is possible only via a separate unlocking mechanism, which is complex to operate or which typically can be found only after searching through the operating instructions for the vehicle. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, a motor vehicle sliding door provides a possibility, in the event of failure of the motorized actuation device of the locking latch, of achieving an intuitive unlocking and locking of the sliding door in the open position thereof. The locking latch has a resiliently loaded overload lever, in that the overload lever forms a lateral portion of the receiving region of the locking latch, and in that, when the locking latch is locked, the overload lever can be pivoted outward when a specific pushing force of the sliding door is exceeded. 
     Therefore, when the motorized actuation device of the locking latch fails, which device is provided per se for easy locking and unlocking of the sliding door in the open position thereof, the sliding door can consequently readily be locked and also unlocked manually by overcoming a specific resistance. The resiliently loaded overload lever which is provided on the locking latch only has to be overcome, without complex considerations being placed upon the operator. 
     If, therefore, with the sliding door open, the pushing force applied to the sliding door exceeds a specific value in the unlocking direction, the overload lever can pivot outward and in this instance release the sliding door. When the sliding door is opened and is intended to be locked, the overload lever also pivots outward when a pushing force which is applied to the sliding door is exceeded and then pivots as a result of the resilient loading back into the locking position thereof so that the sliding door is locked. 
     The locking latch is preferably constructed as a rotary latch, whereby relatively simple and reliable construction is possible. The rotary latch can be readily locked by mean of a locking detent in that the rotary movement of the rotary latch is blocked. The locking detent is preferably actuated in an electromotive manner. The locking detent is advantageously pretensioned by means of a locking detent spring in the direction toward the locked position thereof. It is thereby ensured that the locking detent blocks the locking latch in the normal position thereof. An electromotive actuation of the locking detent is then required only to release the locking latch. 
     The overload lever may be pivotable about an axis which extends transversely through the locking latch. In order to achieve the resilient tension acting on the overload lever, there may be provided a helical or spiral spring which can be readily installed in the smallest space and which produces a reliable pretensioning. The overload lever advantageously has at the side thereof located inside the receiving region an inclined actuation portion for the catch element which is provided on the sliding door. If, therefore, the sliding door is intended to be unlocked with the locking latch blocked, the catch element provided on the sliding door thus presses against the inclined actuation portion of the overload lever, pivots it and is thereby released. 
     Furthermore, the overload lever has, at the side thereof facing away from the receiving region, an inclined approach portion for the catch element which is provided on the sliding door. When the sliding door is moved into the open locked position, the catch elements strikes this inclined approach portion, thereby lifts the overload lever and then engages in the receiving region of the rotary latch. 
     The catch element which is provided on the sliding door is preferably constructed as a guiding roller which is round in cross section. The guiding roller is in this instance advantageously rotatably supported so that the locking and unlocking of the sliding door is thereby facilitated. In accordance with the round cross section of the guiding roller, the receiving region of the locking latch, which region serves to lock the guiding roller, may be constructed in the manner of a circular arc. Other forms of the receiving region are also possible in accordance with the respective configuration of the catch element. 
     These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a view of the locking latch which is constructed as a rotary latch shown in the locked state; 
         FIG. 2  is a view of the locking latch of  FIG. 1 , but with the rotary latch shown unlocked; 
         FIG. 3  is a view of the locking latch of  FIG. 2 , in which the locking latch is locked and the unlocking is carried out by the resiliently loaded overload lever; 
         FIG. 4  is a view of the locking latch in the locked position, in which the locking of the sliding door is intended to be carried out by redirection of the resiliently loaded overload lever; 
         FIG. 5  is a view of the locking latch of  FIG. 4 , in which the overload lever is raised by the catch element of the sliding door; 
         FIG. 6  is a view of the locking latch of  FIGS. 4 and 5  in which the catch element of the sliding door assumes the locked position; and 
         FIG. 7  is a block diagram of a motor vehicle sliding door employing the locking latch. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1-6  of the drawings substantially show the locking latch which is constructed as a rotary latch  2  and which is provided for a motor vehicle sliding door  24  shown in  FIG. 7 . The rotary latch which can be pushed back and forth by means of a sliding movement between an open and closed position. The rotary latch  2  illustrated in the drawing  FIGS. 1-6  serves to lock the sliding door in the open position thereof. In this instance, the rotary latch  2  forms a mechanical door stop and has a receiving region  8  for a catch element of a sliding door. The catch element is in the embodiment illustrated in the drawings constructed as a guiding roller  5  which is round in cross section and which is rotatably supported on the sliding door. 
     In  FIG. 1  of the drawings, the rotary latch  2  is retained in the locked position thereof by means of a locking detent  1 . In the locked position, the guiding roller  5  which is provided on the sliding door is located in the receiving region  8  of the rotary latch  2 , whereby a locking of the open sliding door is ensured. 
     The locking detent  1  can be actuated by means of an electromotive drive  22  which is illustrated in  FIG. 7  operatively coupled to the locking latch  2  which, in turn, operates with the motor vehicle sliding door  24 . When the locking detent  1  is actuated, the rotary latch  2  is unlocked and can then assume the unlocking position illustrated in  FIG. 2 . In this position, the sliding door can be comfortably pushed into the locking position and released from it again without a relatively great application of force being required from an operator. 
     When the sliding door is opened and in order to lock the sliding door in the open position thereof, the guiding roller  5  can be readily introduced in the direction of the arrow  10  into the rotary latch  2 . As soon as the guiding roller  5  has reached the receiving region  8  and presses against the left-hand portion of the receiving region  8  in  FIG. 2 , the rotary latch  2  pivots into the locked position thereof in which the locking detent  1  as a result of a pretensioning applied by the locking detent spring  3  engages in the position illustrated in  FIG. 1 . 
     If the sliding door is subsequently intended to be closed again and has to be unlocked for this purpose, the locking detent  1  is moved via the electromotive drive thereof counter to the force of the locking detent spring  3  into the position illustrated in  FIG. 2 , in which the guiding roller  5  can be pushed back in the direction of the arrow  9  comfortably and with little application of force into the closed position thereof. 
     Should the electromotive actuation mechanism ever fail, for example, in the event of a power failure or in the event of mechanical damage of the transmission mechanism between the electromotive drive and the locking detent  1 , assistance is provided by the construction of the locking latch, according to the invention. 
     To this end, there is provided on the rotary latch  2  an overload lever  6  which can be pivoted about an axis  7  which extends transversely through the rotary latch  2 . The overload lever  6  forms at the right-hand side of the drawing figures a lateral portion of the receiving region  8  of the rotary latch  2 . The overload lever  6  is held by means of an overload spring  4  in the position which is illustrated in  FIG. 1  and in which the receiving region  8  maintains a circular-arc form which is adapted to the cross section of the guiding roller  5 . 
     In  FIGS. 4-6 , it is shown how the locking of the sliding door can be carried out when the electromotive actuation mechanism for the rotary latch  2  fails. In this instance, the locking detent  1  remains in the locking position thereof so that the rotary latch  2  cannot assume the unlocking position illustrated in  FIG. 2 . 
     In order to lock the sliding door in the open position thereof, the guiding roller  5  of the sliding door moves according to  FIG. 4  in the direction of the arrow  10  against an inclined approach portion  11  which is provided on the overload lever  6 , whereby the overload lever  6 , when the guiding roller  5  is moved further in the direction of the arrow  10 , is lifted counter to the force of the overload spring  4  into the position illustrated in  FIG. 5 . 
     When the guiding roller  5  finally assumes the locking position which is illustrated in  FIG. 6  and in which it is located in the receiving region  8 , the overload lever  6  pivots downward as a result of the force applied by the overload spring  4  and closes the receiving region  8  so that the guiding roller  5  is securely locked in the rotary latch  2 . 
     The unlocking of the guiding roller  5  and consequently the sliding door is carried out in the reverse order to the locking. 
     If the pushing force applied to the sliding door in order to close the sliding door exceeds a specific magnitude, the guiding roller  5 , as illustrated in  FIG. 3 , presses against the inner inclined portion  12  of the overload lever  6  so that it is lifted counter to the force of the overload spring  4 . The guiding roller  5  can then move in the direction of the arrow  9  out of the receiving region  8 . 
     When the guiding roller  5  has reached the unlocked position illustrated in  FIG. 3 , the sliding door can be pushed with little force into the locked position thereof. 
     As a result of the invention, there is thus provided a sliding door mechanism, by means of which, using an electromotive actuation mechanism which releases the locking detent  1  and consequently the rotary latch  2 , the sliding door of a vehicle can be locked comfortably and with little force in the open position and can subsequently be unlocked again. However, in the event of failure of this system, it is further possible to lock and unlock the sliding door by means of the overload lever  6  by the pushing force which is applied to the sliding door being increased slightly in order to exceed a critical magnitude of the pushing force, at which the sliding door can then be locked and subsequently unlocked again. 
     It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.