Abstract:
The invention is a locking device for fastening a vehicle seat to a floor of the vehicle. The device allows both fastening and unfastening via structure that compensates for tolerances and helps ensure a rattle-free connection.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The invention relates to a fastening device for seats, seat benches or the like on the floor of a motor vehicle or the like, with a floor-mounted locking dog with a blocking projection spaced apart from the floor and with a fastener, having a blocking slide with a capture opening for the locking dog, which blocking slide can be displaced, in a manner controlled by means of a trigger, out of an open position into a fastening position, in which it engages under the blocking projection by means of the opening edge. 
     A fastening device of the above-mentioned type forms the subject matter of a patent application 197 53 538.0, which is not a prior publication, a locking member being provided which holds the blocking slide in the release position during decoupling by positive interengagement. The locking dog, for its part, is provided with a mushroom head which interacts with the blocking slide in the manner of a bayonet-type joint, more specifically by means of actuation of the locking member by a projection on the vehicle floor. 
     SUMMARY OF THE INVENTION 
     The subject matter of the invention is based on the object of configuring a fastening device of the introductory-mentioned type in such a way that installation tolerances are compensated for by a large-dimensioned capture opening in the blocking slide and that firm, rattle-free interconnected engagement between the locking dog and the blocking slide is nevertheless achieved. 
     This object is achieved first of all and essentially in a fastening device of the introductory-mentioned type wherein a clamping member is provided which, in the fastening position, enters the displaced capture opening and wedges against the locking dog. 
     The significant advantage of the configuration according to the invention is that larger installation tolerances can be compensated for and a stable connection between the fastener on the seat and the locking dog on the vehicle floor can nevertheless be achieved. As soon as the locking dog has passed through the capture opening in the blocking slide, the said opening being larger in relation to the outline of the said dog, the blocking slide returns under spring loading into its blocking position. The clamping member is concomitantly released, moving into a wedging clamping position relative to the locking dog. Here, the clamping member can be supported on that rim edge of the capture opening which lies opposite the opening edge, the blocking slide being held in a clamping position relative to the locking dog, which also excludes return displacement of the blocking slide into its release position. In detail, the clamping member is constructed in such a way that it forms a wedging surface by means of which it acts on a likewise wedge-shaped mating surface of the locking dog. The wedging surface and the mating wedging surface preferably slope at the same angle. Stable fixing of the seat in the second dimension is achieved by virtue of the fact that the wedging portion of the clamping member is plastic-coated and the mating surface of the locking dog forms toothing extending in the direction of displacement. When the wedging surface and the mating wedging surface move up against one another, digging in accordingly occurs, bringing about interconnected engagement transversely to the direction of displacement of the blocking slide. Provision is made for the clamping member to enter the capture opening under spring loading after corresponding displacement of the blocking slide. The clamping member is provided with a stand-by position by being supported on the broad face of the blocking slide in the open position. As soon as the blocking slide is displaced into its blocking position when the locking dog enters the capture opening, the clamping member is deprived of support on the broad face after a corresponding displacement distance, allowing it to enter the capture opening under spring loading and receive support on the mating surface of the locking dog with its wedging surface. To enable the vehicle-mounted fastener to be released from the locking dog, the clamping member can be dragged along out of its clamping position by a pivotable opening lever, the pivoting of which effects displacement of the blocking slide back into the open position. It should furthermore be emphasized that the clamping member is constructed as a clamping slide. The guide for the latter is situated on the fastener housing. Provision is then made for a trigger to sense the end face of the locking dog. After a corresponding entry distance of the locking dog into the fastener, the trigger brings about release of the blocking slide, which moves under spring action into its position of engagement behind the locking dog. To obtain anchoring between the locking dog and the fastener in the third dimension as well, another clamping member is provided and, in the fastening position, this moves up against the end and wedges between the fastener housing and the end of the locking dog. This clamping member is configured as a rotary wedge. The rotary wedge concerned is displaced back out of the clamping position with the clamping slide during opening actuation. This is accomplished by means of a driver pin of the clamping slide, which driver pin projects with clearance through a driver opening in the rotary wedge and is taken along by the opening lever during the opening actuation. The latter accordingly performs a dual function, serving, on the one hand, to displace the blocking slide back and, on the other hand, to take the clamping slide along. To enable this to be accomplished, the blocking slide can be displaced into its open position by a lever arm of the opening lever. The blocking slide is held in this position by means of the trigger in its latching position. The trigger can be configured as a feeler. However, it is also possible to construct the trigger as a pivoted lever. In the latter version, it is advantageous in terms of control that the trigger holds the blocking slide in the open position by engagement in the capture opening. When the seat is placed on the vehicle floor, the locking dog moves the trigger out of the region of the capture opening, after which the blocking slide is released for its displacement into the position in which it engages behind. Finally, an advantageous feature consists in the trigger tensioning the blocking-slide displacement spring during its displacement under the action of the end face of the locking dog. 
     Another version is characterized by the fact that the blocking slide is displaced into the blocking position by the entry movement of the locking dog into the capture opening. This ensures at all times that the blocking slide enters into engagement with the locking dog, even in the event of stiffness, which can arise, for example, due to soiling etc. In detail, the situation here is such that the forcible displacement of the trigger, which passes through a free travel, is controlled. This means that the displacement of the blocking slide into its locking position takes place only when the trigger has passed through the corresponding free travel. The blocking slide can thus not attempt to move into its blocking position too early. The forcible control is achieved in a simple manner by virtue of the fact that the trigger, which is constructed as a pivoted lever, travels freely in the same direction as the entry movement and, in the process, its spindle is guided in a rotation-inhibited manner in a housing slot which, at the end, forms a pivoting clearance, with the result that a driving arm of the pivoted lever displaces the blocking slide into its blocking position. Only when the spindle has traversed the housing slot and is at the level of the pivoting clearance can the pivoted-lever trigger pivot under the control of the locking dog, simultaneously taking along the blocking slide into its blocking position. For this purpose, the driving arm has a pin which engages in a driver slot extending transversely to the direction of displacement of the blocking slide. The pin/slot control system of the blocking slide is thus one which can be manufactured in an advantageous manner in terms of production technology. To obtain rattle-free locking positions, elastic transverse support of the pin in the driver slot is provided. This can be accomplished, for example, by the wall of the driver slot being elastically padded. A reversal would likewise be possible, with the pin being given rubber-elastic padding arranged concentrically to it. According to the invention, another advantageous feature consists in that the linear displacement is performed against the force of a return spring. The latter performs a dual function by virtue of the fact that it is the spring which loads the clamping member. Tolerances are compensated for in a simple manner in the blocking position by virtue of the fact that the blocking projection forms a slope under which an oblique blocking surface of the blocking slide can engage. To be able to transfer the blocking slide from its blocking position into the open position, a reverse displacement of the blocking slide is required. This takes place against the force of the return spring acting on the trigger. Accordingly, the pivoted-lever trigger pivots, with the result that the spindle moves out of the pivoting clearance into an aligned position with the housing slot. During the pivoting displacement of the pivoted-lever trigger, the feeler arm formed by the trigger lever slides on an oblique end face of the locking dog. This oblique end face falls away in the direction of the blocking projection, this proving advantageous during the pivoting back of the trigger. Finally, it should be emphasized that the return spring is a torsion spring, one leg of which acts on the noncircular spindle of the release lever and the other leg of which acts on the clamping member. Accordingly, a single spring is sufficient for fastening, a factor which contributes to a saving in production costs. This configuration furthermore leads to simplified assembly of the fastening. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Three exemplary embodiments of the invention are explained below with reference to the Figures of the drawings, in which 
     FIG. 1 shows schematically a seat fastened to the vehicle floor by means of the fastening device according to the invention, 
     FIG. 2 shows, in a detailed representation, a plan view of the fastener, which has entered into interconnected engagement with the locking dog, the illustration relating to the first embodiment, 
     FIG. 3 shows the section along the line III—III in FIG. 2, 
     FIG. 4 shows the section along the line IV—IV in FIG. 2, 
     FIG. 5 shows the section along the line V—V in FIG. 4, 
     FIG. 6 shows a perspective illustration of the fastener with the locking dog caught by it, 
     FIG. 7 shows a plan view of the fastener during the opening actuation, 
     FIG. 8 shows an illustration comparable with FIG. 3 but during the opening actuation, 
     FIG. 9 shows a section comparable with FIG. 4, likewise during the opening actuation, 
     FIG. 10 shows the fastener during opening actuation, in perspective representation, 
     FIG. 11 shows an illustration comparable with FIG. 3, the fastener and the locking dog being separated from one another, 
     FIG. 12 shows a section comparable with FIG. 4 but relating to the open position of the fastener, 
     FIG. 13 shows a plan view of the fastener relating to the second embodiment, with the locking dog caught by the fastener, 
     FIG. 14 shows the section along the line IVX—IVX in FIG. 13, 
     FIG. 15 shows the section along the line VX—VX in FIG. 13, 
     FIG. 16 shows a perspective illustration of this fastener in the position in which it traps the locking dog, 
     FIG. 17 shows a plan view of the fastener with the opening lever actuated, 
     FIG. 18 shows a section comparable with FIG. 14, the opening lever being actuated, 
     FIG. 19 shows a section comparable with FIG. 15, likewise with the opening lever pivoted, 
     FIG. 20 shows a perspective representation of the fastener with the opening lever pivoted, 
     FIG. 21 shows an illustration comparable with FIG. 14 but with the fastener raised from the locking dog, 
     FIG. 22 shows an illustration comparable with FIG. 15, this likewise being the position in which the fastener and the locking dog are separated, 
     FIG. 23 shows the section along the line XXIII—XXIII in FIG. 24 relating to the open position of the fastener, 
     FIG. 24 shows the plan view of FIG. 23, 
     FIG. 25 shows an illustration corresponding to FIG. 23 but during the closing operation, 
     FIG. 26 shows the follow-up illustration to FIG. 25, relating namely to the locking position, and 
     FIG. 27 shows the fastener in perspective representation in the locking position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       1  denotes a vehicle seat overall. This has a seat cushion  2  and a back rest  3  associated with the latter in an articulated manner. The seat cushion  2  rests on a supporting frame  4 , from which two pairs of parallel feet  5 ,  6  project downward. The front feet  5  can be associated with studs  7  on the vehicle floor by means of a bayonet joint, for example. To fix the rear area of the vehicle seat  1 , i.e. the feet  6 , each foot  6  is assigned a fastening device  8 . This comprises a fastener  9  built into each foot  6  and a locking dog  10  on the vehicle floor, which interacts with said fastener. 
     The foot  6  is shaped to form a box-shaped fastener housing. The housing base  11  has an access opening  12  for the locking dog  10 . The latter is secured on the floor panel  13  (illustrated schematically in FIG. 1) of a motor vehicle. Projecting from the upper end of the locking dog  10  is a blocking projection  14  which extends parallel to the floor panel  13 , the locking dog  10  thus forming approximately a T shape in outline. In its interior, above the housing base  11 , the fastener housing accommodates a blocking slide  15  which is guided parallel to said base. Compression springs  16  engage on that end of the blocking slide  15  which points in the direction of travel. The blocking slide  15  is held in its release position by a trigger  17  which, according to the first exemplary embodiment, is configured as a pivoted lever. This pivoted-lever trigger  17  has an angled shape. Bearing tabs  19  emanate from one angle leg  18  of the trigger  17 . A bearing journal  21  seated in the housing side walls  20  passes through these tabs. Arranged on this journal is a torsion spring  22  which loads the pivoted-lever trigger  17  in the clockwise direction. The pivoting of the trigger  17  in the clockwise direction is limited by a stop pin  23 . In this position, the other angle limb  24  of the pivoted-lever trigger  17  engages in a capture opening  25  in the blocking slide  15  and limits the displacement of the latter caused by the compression springs  16 . This assumes that the spring force of the torsion spring  22  is greater than that of the compression springs  16 . The capture opening  25  is similar in outline to the locking dog  10  but is larger and is aligned with the locking dog  10 , cf. FIG.  12 . 
     On the other side of the capture opening  25 , the blocking slide  15  continues with a transversely oriented supporting beam  26  of larger cross section. Above the latter and supported by the housing side walls  20  is a crossmember  27  which, on the side facing the trigger  17 , has a vertically oriented guide groove  28  for a clamping member  29 . This clamping member is constructed as a clamping slide. Engaging on its upper face is a compression spring  30  which loads the clamping slide  29  in a downward direction. The downward displacement is limited by the broad face of the blocking slide  15 , said face being situated between the supporting beam  26  and the opening edge  25 ′ of the capture opening  25 . The angle limb  24  of the pivoted-lever trigger  17 , which represents a pushbutton, rests against the opening edge  25 ′′ lying parallel to and opposite the opening edge  25 ′, cf. in this regard FIGS. 11 and 12. 
     On its side facing the angle lever  24 , the lower end  29 ′ of the clamping member  29 , said end being offset in a step shape, forms a wedging surface  31 . The wedging portion, i.e. the lower end  29 ′ of the clamping member  29 , is sheathed by a plastic layer  32 . This is a plastic which can be pressed in and will recover. Interacting with the plastic-coated wedging portion is a mating surface  33  of the locking dog  10 . This mating surface  33  is likewise aligned in the form of a wedge and extends parallel to the wedging surface  31  of the clamping member  29 . The mating surface  33  forms toothing  34  which faces in the direction of displacement of the clamping member  29  and by means of which the locking dog  10  digs into the plastic layer  32  in the fastening position in accordance with FIGS. 4 and 5, thereby fixing the fastener  9  and the locking dog  10  relative to one another in the transverse direction. 
     The clamping member  29  in the form of a clamping slide is penetrated by a coupling pin  35 . The ends of the coupling pin, which project beyond the clamping member  29 , are guided in vertical slots  36  in the housing side walls  20 . The coupling pin  35  passes with clearance through a driver opening  37  in another, double-layer clamping member  38 , which is configured as a rotary wedge. The clamping member/rotary wedge  38  is pivoted on a spindle  39  belonging to the fastener housing and is loaded in the clockwise direction by a torsion spring  40  situated on the spindle  39 . In the open position of the fastener in accordance with FIGS. 11 and 12, the upper edge of the driver opening  37  acts on the coupling pin  35  and hence limits the pivoting movement of the clamping member/rotary wedge  38 . The wedging surface  41  of the clamping member/rotary wedge  38  extends eccentrically to the spindle  39 . 
     The fastener housing also supports an opening lever  43  about a journal  42  supported by the housing side walls  20 . This lever has an actuating arm  44  which extends outside the fastener housing, parallel to one housing side wall  20 , and has an actuating handle  45  at its free end. Connected to the actuating arm  44  in terms of effect, within the fastener housing, is a lever arm  46  which interacts with the blocking slide  15  or, more precisely, the supporting shoulder  26  of the latter. The actuating arm  44  extends underneath the coupling pin  35  of the clamping slide  29  and hence serves to displace the latter. The opening lever  43  can be acted upon in the clockwise direction by a spring (not illustrated) and its lower position can be limited by a stop. 
     The following mode of action is obtained: once the front feet  5  of the vehicle seat  1  have entered into interconnected engagement with the stud  7 , the rear area of the vehicle seat can be brought into interconnected engagement with the vehicle floor  13 . This results in the position shown in FIGS. 11 and 12, in which figures the locking dog  10  is still in front of the entry opening  12  in the housing base  11 . As the rear area of the vehicle seat  1  is lowered further, the locking dog  10  enters the entry opening  12  in the housing base  11 . As it passes through the entry opening  12 , the end face  10 ′ of the locking dog  10  acts on the angle limb  24  of the pivoted-lever trigger  17  and displaces the latter against spring loading. The locking dog  10  then enters the capture opening  25  in the blocking slide  15  and traverses this opening, the trigger  17  being pivoted and thereby releasing the blocking slide  15  for spring-loaded displacement once the blocking projection  14  of the locking dog has moved completely through the capture opening  25 . Due to the displacement of the blocking slide  15 , the clamping slide  29  loses its support on the broad face, with the result that it moves rapidly under spring loading in the direction of the locking dog  10 , the wedging surface  31  of the clamping slide  29  entering into engagement with the toothed mating surface  33  of the locking dog, cf. FIGS. 4 and 5. In this position, the opening edge  25 ′′ of the capture opening  25  is supported on the clamping member  29 , while the opposite opening edge  25 ′′ of the capture opening  25  is clamped against the locking dog  10  under the projection  14 . 
     As a concomitant of the downward displacement of the clamping slide  29 , the coupling pin  35  releases the rotary wedge  38  for spring-induced pivoting, its wedging surface  41  pressing against the end face  10 ′ of the locking dog  10  and hence effecting clamping in the third dimension between the fastener  9  and the locking dog  10 . 
     Installation tolerances between the fastener  9  and the locking dog  10  can accordingly be compensated for by means of a capture opening  25  of relatively large dimensions. Nevertheless, the connection between the fastener and the locking dog does not rattle in the fastened position. 
     To remove the vehicle seat  1 , the fastener  9  and the locking dog  10  must be separated. This is accomplished by pivoting the actuating arm  44  of the opening lever  43  in the clockwise direction. During this process, the actuating arm  44  acts on the coupling pin  35  and displaces the clamping slide  29  in such a way that the lower end  29 ′ of the latter leaves the capture opening  25 . The clamping member/rotary wedge  38  is also pivoted out of engagement by the coupling pin  35 . After a delay, the lever arm  46  of the opening lever  43  acts on the supporting beam  26  of the blocking slide  15  and displaces the latter into its release position against the force of the compression springs  16 . In the final phase of the displacement of the blocking slide, the angle limb  14  of the trigger  17  can enter the capture opening  25  and fix the latter, thus giving the position in accordance with FIGS. 8 to  10 . Centering wedges  47  on the sides of the housing side walls  20  then hold the blocking slide  15  in a position in which the capture opening  25  is in alignment with the entry opening  12  and the locking dog  10 . 
     In the second embodiment in accordance with FIGS. 14 to  22 , identical components bear identical reference numerals. The trigger  48  is now configured as a pushbutton which can be displaced in a linear manner. It has a pushbutton pin  49  which is guided in the vertical direction in the fastener housing and is loaded in a downward direction by a compression spring  50 . In the release position of the blocking slide  15 , the lower end of the pushbutton pin projects slightly above the housing base  11 , cf. FIGS. 21 and 22. At its upper end, the pushbutton pin  49  is traversed by a coupling pin  51  which, for its part, interacts with an angled transmission lever  52 . The latter is pivoted on a bearing journal  53 . The coupling pin  51  can be guided by means of its ends in vertical slots in the housing side walls  20 , although this is not illustrated. The lower end of these longitudinal slots which are not shown limits the downward movement of the pushbutton  49 . As regards the transmission lever  52 , this is an angled lever, one lever arm  52 ′ of which interacts with the coupling pin  51 , while the other lever arm  52 ′′ acts via a tension spring  54  on the blocking slide  15 . According to FIGS. 21 and 22, this tension spring  54  is in the unextended position. As a result, the blocking slide  15  is held in its release position, in which its capture opening  25  is in alignment with the entry opening  12  and with the locking dog  10 . In this position, the clamping member  29  is supported on the corresponding broad face of the blocking slide  15 . The coupling pin  35  of the clamping member  29  interacts with the opening lever  43 . In this version too, a clamping member/rotary wedge as in the first embodiment can be provided. 
     The mode of operation of the fastener in accordance with the second embodiment is as follows: When the rear area of the vehicle seat is placed on, the position in accordance with FIGS. 21 and 22 is obtained. As the vehicle seat is displaced further in the direction of the locking dog  10 , the latter acts on the trigger  48  and displaces the latter in the inward direction. As long as the blocking projection  14  is still within the capture opening  25 , the blocking slide  15  cannot move. Owing to the actuation of the pushbutton pin  49 , concomitant pivoting of the transmission lever  52  in the counterclockwise direction takes place via the latter, with the tension spring  54  being tensioned. As soon as the blocking projection  14  of the locking dog  10  is above the blocking slide  15 , a displacement of the blocking slide  15  into the locking position can take place due to the force of the tension spring  54 , the clamping member  29  losing its support on the broad face of the blocking slide  15  and moving forward rapidly under spring loading in the direction of the locking dog  10 , and its wedging surface  31  coming to rest against the mating surface  33  of the locking dog. A sturdy connection has thus been established between the fastener  9  and the locking dog  10 , cf. FIGS. 13 to  16   
     To separate the fastener  9  from the locking dog  10 , the opening lever  43  must be pivoted into the position shown in FIGS. 18 to  20 . During this process, the coupling pin  35  is acted upon and the clamping slide  29  is thus lifted out. After a delay, the lever arm  46  of the opening lever  43  acts on the blocking slide  15  and brings it back into its initial position. The trigger  48  holds the blocking slide  15  in the position shown in FIGS. 18 to  20  by means of the transmission lever  52  and the unextended tension spring  54 , with the result that the clamping slide  29  moves back into its position of support on the broad face of the blocking slide  15  when the opening lever  43  is released. The initial position shown in FIGS. 21 and 22 is then re-established. 
     According to the third embodiment, illustrated in FIGS. 23 to  27 , identical components are provided with identical reference numerals. The trigger  55  is now configured as a pivoted lever. Its spindle  56  is noncircular in shape. It has approximately the shape of an elongate rib. The spindle  56  is guided in vertically aligned housing slots  57  in the housing side walls  20 . At the upper end, each housing slot  57  opens into a pivoting clearance  58 . This makes it possible for the pivoted-lever trigger  55  to pivot in the clockwise direction in accordance with the illustration when the spindle  56  enters. 
     The pivoted-lever trigger  55  has a driving arm  59  and a feeler arm  60 . The driving arm  59  carries a pin  61  which is oriented parallel to the spindle  56  and engages in a driver slot  62  in the blocking slide  15 . Said driver slot  62  is situated in an end pedestal  73  of the blocking slide  15 , which driver slot  62  is arranged transversely to the direction of displacement of the blocking slide  15 . The wall  72  of the driver slot  62  is elastically padded. For this purpose, the wall  72  can be composed of rubber or a corresponding material. 
     Above the housing slots  57 , the housing side walls  20  bear a journal  63  on which a return spring  64  for the pivoted-lever trigger  55  is arranged. The return spring  64  is configured as a torsion spring, one leg  65  acting on the noncircular spindle  56 , while the other leg  66  loads the clamping member  29  in the direction of the broad face of the blocking slide  15 . In the open position, the lower end face  68  of the clamping member  29  is supported on the upper broad face of the blocking slide  15  on the far side of the capture opening  25 , cf. FIG.  23 . The clamping member  29  likewise forms a wedging surface  31  for interaction with the likewise oblique mating surface  33  of the locking dog  10 . A crossmember  27  extending between the housing side walls  20  serves to guide the clamping member  29 . 
     The blocking projection  14  forms a slope  70  under which an oblique blocking surface  69  of the blocking slide  15  can engage, the slope angle of the blocking surface  69  and of the slope  70  being equal. 
     The round-ended feeler arm  60 , mentioned at the outset, of the pivoted-lever trigger  55  interacts with an oblique end face  71  of the locking dog  10 , which oblique end face  71  falls away in the direction of the blocking projection  14 . 
     Finally, an opening lever  43  is also provided in this version, said opening lever having an actuating arm  44  which extends outside the fastener housing, parallel to a side wall  20 , and has an actuating handle  45 . In terms of its action, the actuating arm  44  is connected to a lever arm  46  which is situated within the fastener housing and, for its part, interacts with a supporting shoulder  26  of the blocking slide  15 . 
     In the open position in accordance with FIG. 23, the spindle  56  is at the lower end of the housing slots  57 . The pivoted-lever trigger  55  here holds the blocking slide  15  in a position in which the locking dog is in alignment with the capture opening  25  of the blocking slide  15 . The locking dog  10  is likewise in a position of alignment with the entry opening  12  in the housing base  11 . 
     This fastening device operates as follows: 
     When the vehicle seat is placed on, the locking dog  10  first of all acts on the feeler arm  60  of the pivoted-lever trigger  55  by means of its obliquely extending end face  71 . At the same time, the blocking dog  10  passes through the entry opening  12  and then the capture opening  25 . Thanks to the housing slots  57 , the pivoted-lever trigger  55  is concomitantly displaced in the same direction as the entry movement, cf. FIG.  25 . The noncircular configuration of the spindle  56  prevents the trigger  55  from pivoting. Here, displacement takes place against the force of the return spring  64 . After passing through the relevant free travel without being able to take the blocking slide  15  along in the process, the spindle  56  enters the pivoting clearance  55 , with the result that the trigger  55  can pivot by virtue of the actuation by the locking dog  10 , and this is associated with taking along of the blocking slide  15  into the locking position shown in FIGS. 26 and 27. During this process, the oblique blocking surface  69  of the blocking slide  15  engages under the facing slope  70  of the blocking projection  14 . The clamping member  29  has furthermore lost its end support on the blocking slide  15 , with the result that the torsion spring  64  displaces the clamping member  29  in the downward direction, the wedging surface  31  of the latter acting on the mating surface  33  of the locking dog  10 , the latter thus being flanked by wedging surfaces in the direction of displacement of the slide. By means of the elastic wall  72 , it is furthermore possible to achieve a tightening effect which, in addition to compensating for installation tolerances, leads to a rattle-free connection between the locking dog  10  and the fastener  9 . 
     To release the locking, it is necessary to displace the opening lever  43  by means of the actuating handle  45 , the actuating arm  44  acting on the coupling pin  35  guided in vertical slots  36  and displacing it in an upward direction, the clamping member  29  moving out of its position of engagement. The trigger  55  pivots concomitantly, its spindle  56  passing through the housing slot  57  and returning to the initial position. In conjunction with the pivoting of the trigger  55 , the blocking slide  15  is displaced back into its release position in accordance with FIGS. 23 and 24.