Abstract:
A latch assembly especially for the doors, seats, or seatbacks of motor vehicles with a latch element installed rotatably in a lock housing to retain an opposing latch part when the assembly is in the locking position, which opposing part can disconnect itself from the latch element when the assembly is in a released position. A tensioning element exerts a tensioning force when the assembly is in the locking position, by which a tension edge forming a permanent part of the opposing latch part is pressed against an opposing tension edge forming a permanent part of the lock housing. The tensioning member is a slide plate supported on a guide edge of the lock housing and a certain area of the plate forms a tensioning cam, which is at an angle relative to the movement of the slide plate and which cooperates with a projection on the latch element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority of DE 10 2012 107 185.3, filed Aug. 6, 2012, the priority of this application is hereby claimed and this application is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The invention pertains to a latch assembly especially for the doors, seats, or backrests of motor vehicles with a latch element installed rotatably in a lock housing to retain an opposing latch part when the assembly is in the locking position, which opposing part can disconnect itself from the latch element when the assembly is in a released position; and with a tensioning element, which, when the assembly is in the locking position, exerts a tensioning force by which a tension edge forming a permanent part of the opposing latch part is pushed against an opposing tension edge forming a permanent part of the lock housing. 
         [0003]    DE 10 2005 023 861 A1 describes a rotary latch assembly, in which the rotary latch is held in a locking position by a stop pawl. The stop shoulder of the stop pawl forms a wedge surface which exerts a tensioning force on the rotary latch under the action of a pawl spring, this force pressing the opposing latch part captured in the forked opening of the rotary latch against an opposing tension edge forming a permanent part of the housing. The tension edge is formed in this case by an upper surface section of the opposing latch part situated in the forked opening. 
         [0004]    DE 10 2005 029 079 A1 describes a similar latch assembly. Here the tensioning element is designed so that it exerts a tensioning force on the opposing latch part. DE 10 2004 051 894 A1 also describes a tensioning member which acts directly on the opposing latch part in such as way as to push it against an opposing tension edge forming a permanent part of the housing. 
         [0005]    In the case of the latch assembly described in DE 102 02 344 A1, it is proposed that a tensioning section of the stop pawl be able to move between the inside edge of the forked opening and the opposing latch part and thus exert a clamping action. 
         [0006]    In the case of the latching assembly described in DE 196 39 051, the opposing latch part is clamped between a tension edge of a stop arm of the rotary latch and a tensioning member. 
         [0007]    DE 10 2009 003 706 A1 describes a seatback latching assembly with a rotary latch and a tensioning element. The tensioning element is a slider with a wedge-shaped component. A latch assembly with a tensioning slider with a wedge-shaped component is also disclosed in DE 10 2006 019 347 A1. In the case of the rotary latch assembly described in DE 101 56 200 A1, the exertion of a tensioning force on the rotary latch has the effect of clamping an opposing latch part between the bottom of a capture slot and a fork arm. The tensioning force is applied by a rotating wedge, which is able to turn around a rotational axis forming a permanent part of the housing. 
         [0008]    DE 103 43 622 discloses a latch assembly with a pivot lever, which is supported on one of the arms of a rotary latch, and which comprises a wedge-shaped component, by means of which an opposing latch part can be pushed against the other arm of the rotary latch. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention is based on the goal of elaborating the latch assembly of the general type in question in a manner which offers advantages with respect to practical application. 
         [0010]    The goal is achieved by the invention described in the claims. What is provided first and essentially is that the tensioning member is a slide plate, which is supported on a guide edge of the lock housing, at least a certain area of the slide plate forming a tensioning cam which is at an angle in relation to the movement of the slide plate and which cooperates with a projection on the latch element. In preferred elaborations, which also have independent character, it is provided that the tensioning cam is the boundary edge of a window, especially of a completely enclosed window, in the tensioning member. The window can form an escape space, which follows after the control cam and in which the projection, which cooperates with the tensioning cam to apply the tensioning force, lies when the latch is in the released position. For guidance in the housing, the tensioning member can comprise a slot. A guide pin can engage in this slot. The guide pin can be a projection forming a permanent part of the housing. Preferably, however, the guide pin is designed as a rivet, which serves as a bearing to support the latch element, preferably designed as a rotary latch. The width of the slot corresponds here to the diameter of the hub. The lock can also form a stop pawl, the stop hook of which extends under a stop edge of the latch element when the assembly is in the locking position. When the assembly is under tension, the stop hook can be a certain distance away from the stop edge. The job of the stop pawl can be limited to that of rendering the latching assembly crash-proof. If, for example, the force of an impact causes the tensioning member to shift into the released position, the anti-rattle function is, of course, no longer guaranteed. It is still impossible, however, for the rotary latch to move into its open position, because the stop hook on the stop pawl prevents it from doing so. Only after both the tensioning member and the stop pawl have been moved into their released positions is the rotary latch free to open. This can be done by means of a pretensioned rotary latch spring, which is put under tension when the latch assembly is closed, i.e., when the opposing latch part is captured by the rotary latch. So that this opening process can proceed as intended, an opening lever can be provided. This lever is free to rotate around an opening-lever rotational axis forming a permanent part of the housing. The rotational axis of the opening lever can be the same as the rotational axis of the stop pawl. The opening lever has a first arm. During the pivoting movement of the opening lever in the opening direction, which can be accomplished by pulling on a Bowden cable, for example, the first arm of the opening lever acts on a projection of the tensioning member in such a way as to shift the tensioning member from the tensioning position into a released position. As this is happening, the tensioning member slides along the guide edge forming a permanent part of the housing until the pin of the rotary latch has left the stop edge and has entered the escape space. A second arm of the opening lever cooperates with a driver on the stop pawl. It exerts force on the driver in such a way as to shift the stop pawl out of its stopping position and into the released position. A third arm can be provided, on which the Bowden cable or a linkage acts, the cable or linkage being connected to an actuating lever or the like. The tensioning force can be applied by a tension spring. One end of this tension spring is fastened to a spring support forming a permanent part of the housing. The other end acts on the tensioning member. 
         [0011]    In a preferred embodiment of the invention, which has independent character apart from the design of the tensioning member, it is provided that the opposing tensioning edge is formed by a wall of the housing. The tensioning edge can be designed as a latch member carrier. The tensioning edge can also be formed by the latch member itself, and the opposing tensioning edge can be formed by the bottom of a capture opening in the lock housing. In the preferred embodiment, a tensioning edge of the lock housing moves against an opposing tensioning edge of an opposing latch part carrier during the final phase of the latching movement, i.e., when the door is being closed, the seat is being fastened to the floor of the vehicle body, or the seatback is being raised. These two edges are pressed against each other by the tensioning force of the tensioning member, that is, by the spring acting on the tensioning member. 
         [0012]    The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0013]    In the drawing: 
           [0014]      FIG. 1  shows the latching assembly in the open position, in which the rotary latch has assumed a pivoted position in which it can capture an opposing latch part; 
           [0015]      FIG. 2  shows a diagram similar to  FIG. 1  in which the opposing latch part has been brought into a stop position against an arm  17  of the rotary latch; 
           [0016]      FIG. 3  shows a diagram subsequent to that of  FIG. 1 , in which the insertion movement of the opposing latch part  3  into the capture opening  30  in the housing plate  29  has led to a first displacement of the rotary latch  1 , wherein the opposing latch part carrier  33  and the lock housing  31  have been omitted for the sake of clarity; 
           [0017]      FIG. 4  shows a diagram subsequent to the preceding one, in which the rotary latch  1  has been rotated further and a projection  8  seated on the wide side of the rotary latch has reached the end of an escape space  19 , the opposing latch part carrier  33  and the lock housing  31  again being omitted; 
           [0018]      FIG. 5  shows a diagram subsequent to the preceding one, wherein the pin  8  has reached the tensioning cam  18 , the opposing latch part carrier  33  and the lock housing  31  again being omitted; 
           [0019]      FIG. 6  shows a diagram subsequent to the preceding one, in which the pin  8  has been brought into its tensioning position, i.e., the position in which the tensioning member exerts a tensioning force on the opposing latch part  3  and thus exerts a tensioning surface  32  of the latch member carrier  33  against an opposing tensioning edge  6  of the lock housing  31 ; 
           [0020]      FIG. 7  shows a diagram subsequent to the preceding one after the occurrence of an opening actuation, during which an opening lever  13  has shifted the tensioning member  4  but not, as yet, the stop pawl  9 , the opposing lock part carrier  33  and the lock housing  31  again being omitted; 
           [0021]      FIG. 8  shows another diagram subsequent to the preceding one, in which the opening lever  13  has brought both the tensioning member  4  and the stop pawl  9  into the released position, the opposing latch part carrier  33  and the lock housing  31  again being omitted; and 
           [0022]      FIG. 9  shows a perspective view of the complete latch member carrier  33  and the complete lock housing  31  in the locking position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    The lock shown in the drawings has an outer lock housing  31 , which carries in turn a housing plate  29 , certain parts of which project beyond a boundary edge  6  of the lock housing  31 . One edge  6  of the lock housing  31  forms an opposing tensioning edge. The opposing tensioning edge can be formed by a base plate  40 , which is permanently connected to the lock housing  31 . The opposing tensioning edge  6  is parallel to a tensioning edge  32 , which is assigned to a latch member carrier  33 , which carries a latch member  3 . Latch member carrier  33 , housing plate  29 , and lock housing  31  can be made of steel. In an open position of the latch assembly, which is shown in  FIG. 1 , the tensioning edge  32  and the opposing tensioning edge  6  are a certain distance apart. In a latching position, which is shown in  FIG. 5 , the opposing tensioning edge  6  and the tensioning edge  32  are resting flat against each other and are being pressed together by the tensioning force of a tension spring  5 , so that the latching part is held against the latch member  3  or latch member carrier by a solid, rattle-free connection. 
         [0024]    The latch assembly is shown in its entirety in  FIG. 9 . It is a floor latch assembly, by means of which a motor vehicle seat can be fastened to the floor of a passenger compartment forming a permanent part of the vehicle body. 
         [0025]    The latch member carrier  33  is permanently connected to the floor of the passenger compartment or is formed by the floor of the passenger compartment itself. This latch member carrier  33  has two opposing latch parts  3 , each of which can work together with a latch assembly, wherein the two lock housings  31  form the legs of a motor vehicle seat. In other exemplary embodiments of the invention, the latch member carrier  33  has only a single opposing latch part. These other exemplary embodiments, which are not shown here, pertain to seatback latch assemblies, in which the latch member carrier can also be a part of the vehicle body or can be permanently connected to the body and in which the lock housing is part of the seatback. The relationships can also be reversed, however. That is, the lock can be permanently connected to the vehicle body, so that the lock housing then forms part of the body. Another exemplary embodiment (not shown) pertains to a door latch, in which the lock housing is either a permanent part of the frame or of the door or is formed by the door itself or by the frame itself. 
         [0026]    All of the essential elements of the latch are mounted on a housing plate  29 . This has a capture opening  30 , which is designed as a slot with a bottom  30 ′. A latch member in the form of a rotary latch  1 , which turns around a rotational axis  24 , is mounted rotatably on the housing plate  29 . A rotary latch spring is provided, which holds the rotary latch  1  in the open position. The rotary latch  1  forms a forked opening, which extends between a latch hook  2  and a rotary latch arm  17  and which is designed to accept an opposing latch part  3  forming a permanent part of the latch member carrier  33 . 
         [0027]    A tensioning member  4  is provided. The tensioning member  4  is designed as a slide plate. The slide plate slides in a direction parallel to that in which the opposing latch part is captured, indicated in  FIG. 1  by an arrow. The tensioning member  4  has a slot, designed as an elongated hole; the width of the slot corresponds to the diameter of an extension  23 , which engages in the slot  2 . The extension  23  is formed by the shaft which supports the rotary latch  1  and has a circular peripheral contour. 
         [0028]    The tensioning member  4  also forms a window  7 , closed on all sides. The window  7 , inside which a pin  8 , permanently connected to the wide side of the rotary latch  1 , travels, has essentially two sections. One section forms an escape space  19 , which has the form of an arc of a circle and in which the pin  8  is located when the rotary latch  1  is in the open position shown in  FIGS. 1 and 8 . A tensioning cam  18  following the escape space  19  extends in a straight line and acts as one side of a wedge, because it extends at a slant to the direction in which the tensioning member  4 , designed as a slide plate, moves. The tensioning member  4  is supported on a guide edge  21 , which is a permanent part of the housing  31  or of the housing plate  29 . The guide edge  21  extends in the direction in which the tensioning slide plate  4  moves, that is, at an angle to the tensioning cam  18 . 
         [0029]    A tension spring  5  is provided, one end of which acts on the tensioning member  4 , while the other end is attached to a spring support  28  permanently connected to the housing. The tension spring  5  is pretensioned and is thus able to hold the tensioning slide plate  4  in the tensioning position shown in  FIG. 6 , in which the tensioning cam  18  is exerting tensioning force on the pin  8 , so that torque is exerted on the rotary latch  1  when it is in the latching position. This torque is transmitted by the edge  2 ′ of the latch hook  2  to the opposing latch part  3 , so that, when the assembly is in the latching position, the tensioning edge  32  is pressed against the opposing tensioning edge  6 . 
         [0030]    A stop pawl  9  is provided, which is rotatably mounted on the housing plate  29  so that it can rotate around a pawl axis  25 . The stop pawl  9  forms a stop hook  10 , which, when the assembly is in the open position shown in  FIG. 1 , lies outside the capture opening  30 . One end of a transmission rod  34  is hinged to a pin  27 , while the other end of the rod is hinged to a pivot lever  35 . When the rotary latch is in the open position ( FIG. 1 ), a retaining means (not shown) holds the stop pawl  9  in a pivoted position such that a stop pawl spring (not shown) cannot move it, as a result of which the stop pawl  9  remains in the open position. 
         [0031]    An indicator pin  37  is provided, which, when the stop pawl is in the opened state, passes through the housing to the outside. One end of the pivot lever  35  acts on the end of the indicator pin  37  located inside the housing. Because the pivot lever  35  is connected by a transmission rod  34  to the pin  27  on the stop pawl  9 , the pivot lever  35  pivots together with the stop pawl  9 . The pivoting movement of the pivot lever  35  is transmitted by a manipulation spring  36  to the indicator pin  37 . The manipulation spring  36  sits on a pin  37 , one end of the spring being supported on the indicator pin  37 , whereas the other end acts on the free end of the pivot lever  35 . When the rotary latch  1  pivots to capture the opposing latch part  3  ( FIGS. 3-5 ), the retaining means which prevents the stop pawl  9  from pivoting under the force of the spring is released. In the latching position of the assembly ( FIG. 6 ), the stop hook  10  extends under the stop edge  11 , remaining a certain distance away from it. Until the stop pawl  9  moves into its released position, the rotary latch  1  cannot pivot into its open position, because, when the rotary latch  1  rotates slightly in the direction toward its open position, the stop edge  11  runs up against the stop hook  10 . 
         [0032]    An opening lever  13  is provided. The opening lever  13  has three lever arms  14 ,  15 ,  16  and is mounted on the housing plate  29  with freedom to pivot around the stop pawl pivot axis  25 . A first opening lever arm  14  cooperates with an extension  12  of the tensioning member  4 . A second opening lever arm  15 , extending more-or-less at a right angle to this first lever arm, is used to rotate the opening lever  13 . A Bowden cable, a handle, or a linkage can act on this second arm to shift the opening lever  15  in the counterclockwise direction away from the locking position shown in  FIG. 6 . The second lever arm has yet another function. During the course of its rotational movement, it runs up against a driver pin  26 , which projects from the wide side of the stop pawl  9 , and thus also shifts the stop pawl  9  into its open position. A spring  39  acts on the third opening lever arm  16 , which is essentially diametrically opposite the first lever arm  14 ; this spring holds the opening lever  13  in a non-actuated position and is put under tension when the opening lever  13  is turned in the opening direction. A Bowden cable, a handle, or a linkage can also act on the opening lever arm  16 . 
         [0033]    The way in which the latch assembly works is as follows: 
         [0034]    In  FIG. 1 , the rotary latch  1  is held in the open position by the rotary latch spring. The stop pawl  9  is in its released position. The opening lever  13  is in its non-actuated position. The opening lever arm  14  is a certain distance away from the extension  12  of the tensioning member  4 . The pin  8  is located in the escape space  19  and holds the tensioning member  4  in the released position. 
         [0035]    When the opposing latch part, which is permanently connected to the latch member carrier  33 , now moves into the capture opening  30 , it runs up against the tip of the rotary latch arm  17 , which projects into the capture opening  30  (see  FIG. 2 ) and pivots the rotary latch  1  into the position shown in  FIG. 3 . During this pivoting movement, the pin  8  travels along the curved retaining shoulder of the escape space  19  and holds the tensioning member  4  in its open position. As the opposing latch part  3  continues to move inward, the pin  8  travels past the end of the curved retaining edge of the escape space  19  (see  FIG. 4 ) and thus reaches the tensioning cam  18  (see  FIG. 5 ). Once this position is reached, the tension spring  5  goes into action; that is, by acting on the pin  8 , it exerts torque on the rotary latch  1  by way of the cam edge  18 , which extends at a slant to the direction in which the tensioning member  4  slides, with the result that the edge  2 ′ of the latch hook  2  of the latch can exert force on the opposing latch part  3 . As this is happening, the tensioning member  4  continues to move until it reaches the tensioning position shown in  FIG. 6 , in which the tensioning edge  32  of the latch member carrier  33  is pressed tightly against the opposing tensioning edge  6  of the lock housing  31 . 
         [0036]    It can derived from  FIGS. 4 and 5  that, during the course of the capture movement of the opposing latch part  3 , the stop pawl  9  shifts in the direction toward its stop position. 
         [0037]    To open the latch assembly, the opening lever  13  must be pivoted against the restoring force of the spring  39  by a Bowden cable or the like acting on the second lever arm  15 , thus moving it from the position shown in  FIG. 6  to the position shown in  FIG. 7 . In the locking position shown in  FIG. 6 , the first arm  14  is a short distance away from the extension  12 . When the opening lever  13  is turned, the extension  12  is subject to the force of the first lever arm  14 , and the tensioning member  4  is thus shifted, wherein, during the course of this movement of the tensioning member  4 , the pin  8  moves along the tensioning cam  18  toward the escape space  19 . 
         [0038]    As it is pivoting into the open position, the second lever arm  15  runs up against the driver  26  of the stop pawl  9  and thus shifts the stop pawl  9  out of its stop position into the release position. 
         [0039]    As soon as the pin  8  travels past the end of the tensioning cam  18 , it can enter the escape space  19 , so that the rotary latch  1  can assume the open position shown in  FIG. 8 . In this position, the stop pawl  9  has been shifted completely into its released position, so that the opposing latch part  3  can move out of the capture opening  30  in the direction of the arrow indicated in  FIG. 8 . 
         [0040]    In the exemplary embodiments which are not illustrated here, the stop parts can be designed in different ways. The rest position of the tensioning member can be achieved by means other than that of a window with a wedge-like contour. The effective force of the tensioning member can be realized not only by a tension spring but also by a compression spring or a leg spring. 
         [0041]    All of the disclosed features are (in themselves) essential to the invention. The disclosure content of the associated/attached priority documents (copy of the prior application) is also included here in its entirety for the purpose, among others, of incorporating features of these documents into the claims of the present application. In their facultatively subordinate version, the subclaims characterize independent inventive elaborations of the prior art, in particular for the purpose of generating divisional applications on the basis of these claims. 
         [0042]    While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.