Abstract:
A locking unit ( 10 ) for a vehicle seat ( 1 ) includes a pawl ( 80 ) which is mounted pivotably about a pivot axis between an open position and a closed position and has a retaining contour ( 27 ) for securing a locking pin ( 12 ) in the closed position. At least one claw ( 90, 91, 92 ) is mounted pivotably about the same pivot axis in a manner offset in the axial direction with respect to the pawl ( 80 ). The claw ( 90, 91, 92 ) has a closing contour ( 25 ). The pawl ( 80 ) is pivotable from the open position into the closed position by the closing contour ( 25 ) being acted upon by the locking pin ( 12 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a United States National Phase Application of International Application PCT/EP2014/069075 filed Sep. 8, 2014, and claims the benefit of priority under 35 U.S.C. §119 of German Patent Applications 10 2013 218 076.4 filed Sep. 10, 2013 and 10 2014 200 012.2 filed Jan. 3, 2014, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a locking unit for a vehicle seat having a locking detent which is pivotably supported about a pivot axis between an open position and a closed position and which has a retention contour in order to retain a locking bolt in the closed position. The invention also relates to a vehicle seat having at least one such locking unit. 
       BACKGROUND OF THE INVENTION 
       [0003]    WO2010/054860 A2 discloses a locking unit of the generic type for a vehicle seat. Such a locking unit comprises a rotary latch which is pivotably supported about a pivot axis for locking with a locking bolt. A catch detent which is pivotably supported about another pivot axis secures the rotary latch in the locked state of the locking unit. A pivotably supported clamping element which is referred to as a tolerance compensation detent applies to the rotary latch a closing moment and thereby eliminates any play which is present between the rotary latch and the locking bolt. 
         [0004]    DE 20 2011 100 040 U1 also discloses a locking unit of the generic type for a vehicle seat. The locking unit has two bearing pins which serve to pivotably support the rotary latch and the catch detent and the clamping element. The two bearing pins also serve to secure the locking unit to the structural component of the vehicle seat and are constructed to be approximately hollow-cylindrical. In order to secure the locking unit to the structural component of the vehicle seat, there are further provided two screws which each engage through one of the two bearing pins and which are screwed into the structural component or an additional nut. 
         [0005]    In the mentioned known locking units, the rotary latch has four contours which fulfill different functions. A retention contour is used to retain the locking bolt in the locked state. A support contour cooperates with the clamping element in order to discharge play and with the catch detent in order to secure the rotary latch in the locked state. A contour for retaining in the open state cooperates with the catch detent in order to secure the catch detent in the unlocked state. A closure contour is used during unlocking of the locking unit in order to eject the locking bolt. When the locking unit is locked, the locking bolt moves into abutment with the closure contour and thereby pivots the rotary latch into the closed position thereof and the locking unit moves into the locked state. 
         [0006]    In the locked state of the locking unit, the rotary latch is in the closed position and the retention contour retains the locking bolt. In the unlocked state of the locking unit, the rotary latch is in the open position. 
         [0007]    Such locking units are used, for example, to lock a backrest of a vehicle seat to a seat member and/or to a bodywork or structure of a vehicle or to lock the vehicle seat to the bodywork or structure of the vehicle. 
         [0008]    It is also possible to lock engine hoods, rear flaps or doors of vehicles with such locking units to the bodywork or structure of the vehicle. 
         [0009]    For example, DE 10 2006 003 022 A1, DE 10 2009 021 297 A1, DE 103 27 448 A1 and DE 10 2009 037 037 A1 disclose such locking units which are also referred to as locks. 
       SUMMARY OF THE INVENTION 
       [0010]    An object of the invention is to improve a locking unit of the type mentioned in the introduction, in particular to reduce the necessary structural space. 
         [0011]    A locking unit of the generic type for a vehicle seat comprises a locking detent which is pivotably supported about a pivot axis between an open position and a closed position and which has a retention contour in order to retain a locking bolt in the closed position. 
         [0012]    In the locked state of the locking unit, the locking detent is in the closed position and the retention contour retains the locking bolt. In the unlocked state of the locking unit, the rotary latch is in the open position. 
         [0013]    According to the invention at least one claw is pivotably supported about the same pivot axis so as to be offset in the axial direction relative to the locking detent, wherein the claw has a closure contour, wherein the locking detent can be pivoted from the open position into the closed position by the closure contour being acted upon by the locking bolt. 
         [0014]    As a result of the provision of a locking detent and at least one claw, which are arranged to be axially offset relative to each other, in place of a rotary latch, the known integration of the retention contour, closure contour, support contour and contour for retaining in the open state is advantageously divided over a rotary latch. 
         [0015]    The integration division allows a smaller structural space because an optimum spatial nesting of the components can be achieved as a result of the described multi-component configuration. The multi-component configuration allows the division of regions which take up high loads and regions which are subjected to lower loads over separate components. More regions can thereby be constructed from light materials and the overall weight is reduced. 
         [0016]    A locking detent having a retention contour is therefore connected to at least one claw so that the locking detent can be moved from an open position into a closed position by a closure contour located on the claw being acted on accordingly. 
         [0017]    It is thereby possible to configure the shape of a locking detent having a retention contour in such a manner that its contact location with respect to a locking bolt is in approximately the same plane perpendicular to the pivot axis thereof or the instantaneous center of rotation thereof as a contact location of the locking bolt with respect to a stop element. 
         [0018]    Therefore, the locking unit preferably comprises a stop element which is arranged in such a manner that, when the locking unit is locked, the locking bolt abuts the stop element in a first contact location and the retention contour in a second contact location, wherein the first contact location and the second contact location are located at least approximately in a plane which extends perpendicularly to the axial direction. 
         [0019]    The locking detent having a retention contour does not thereby have to move, or has to move less, about the pivot axis thereof in order to compensate for angular deviations of the locking bolt relative to the pivot axis thereof. 
         [0020]    A clamping element which drives the claw can then be constructed so as to have a mean contact angle which is smaller over the contact region with respect to the claw for the same pivot range. 
         [0021]    For the same drive moment of the clamping element, the clamping element therefore begins to move only in the event of higher forces which act on the locking detent in an opening manner. 
         [0022]    The simultaneous contact of the locking bolt with the stop element and the retention contour of the locking detent is thus also retained in the event of higher dynamic excitations of the locking bolt and noises as a result of changing contact conditions between the locking detent, the locking bolt and the stop element are avoided. 
         [0023]    The arrangement of the closure contour on a claw which is arranged to be offset relative to the locking detent allows the locking detent to be formed in such a manner that the locking detent can move from the closed position into the open position without colliding with the stop element which is arranged in the same functional plane. 
         [0024]    The stop element is preferably arranged to be offset relative to the claw in an axial direction. The claw thereby pivots past the stop element during locking and unlocking of the locking unit. 
         [0025]    According to an advantageous embodiment of the invention, the claw has a support contour which cooperates in the closed position of the locking detent with a catch detent in order to secure the locking detent and/or with a clamping element in order to discharge play of the locking detent. 
         [0026]    Therefore, the locking detent is connected to at least one claw which is arranged in an axially offset manner with respect to the contact region of the locking bolt with the locking detent. There is located on at least one claw which is arranged in this manner and which is connected to the locking detent the support contour which also ensures load absorption at the contact region of the locking detent with respect to the locking bolt at forces which can bring about a movement of the clamping element. 
         [0027]    The clamping element is preferably pivotably supported about a second pivot axis which extends parallel with the pivot axis of the locking detent. However, for example, it is also conceivable for the clamping element to be constructed as a wedge which is guided in translation movement. 
         [0028]    According to another advantageous embodiment of the invention, the claw has a contour for retaining in the open state which cooperates with a catch detent in order to secure the catch detent in the open position of the locking detent. 
         [0029]    A contour for retaining in the open state which is arranged on an additional component or on the claw therefore retains the claw and a catch detent which abuts it in the open position. 
         [0030]    Alternatively, the contour for retaining in the open state may also be located on a stop element which is movably connected to the housing in the functional plane of the first detent. 
         [0031]    The locking detent and the claw are preferably connected to each other in a rotationally secure manner in both pivoting directions. The connection of the components locking detent and claw, which are arranged in offset functional planes, can be brought about in a positive-locking, non-positive-locking or materially engaging manner. The connection may also partially act only in one movement direction. 
         [0032]    According to an advantageous development of the invention, the locking device comprises two connection plates which extend parallel with each other and which have two retention holes in which a bearing pin is inserted, respectively, and a retention opening, in which a retention bolt having a gripping opening is inserted, wherein the retention opening and/or the gripping opening is/are constructed as a slot. It is thereby possible to adapt the locking unit to different gauges of the vehicle seat. 
         [0033]    According to an advantageous development of the invention, the locking detent and the claw are partially surrounded by a common covering which preferably comprises a plastics material. As a result, in an advantageous manner, a reduction of the occurrences of noises can be brought about during closure or opening of the detent as a result of the contact with the bolt. 
         [0034]    According to an advantageous development of the invention, the claw has a support contour, a closure contour, a contour for retaining in the open state and a projection having a retention contour. 
         [0035]    The covering preferably covers at least the retention contours of the projections of the locking detent and the claw. 
         [0036]    The covering preferably has a convex curvature in the region of the retention contours so that, in the locked state of the locking unit, the contact locations of the locking bolt with respect to the covering of the retention contours and with respect to the stop element are approximately in a plane which extends perpendicularly to the axial direction. 
         [0037]    The object is also achieved by a vehicle seat which has a locking unit according to the invention. 
         [0038]    The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]    In the drawings: 
           [0040]      FIG. 1  is a schematic side view of a vehicle seat; 
           [0041]      FIG. 2  is an exploded view of a locking unit of the generic type in accordance with the prior art; 
           [0042]      FIG. 3  is a schematic side view of an additional locking unit of the generic type in accordance with the prior art in the unlocked state; 
           [0043]      FIG. 4  is a schematic side view of the locking unit according to  FIG. 3  in the locked state; 
           [0044]      FIG. 5  is a schematic side view of a first embodiment of a locking unit according to the invention in the unlocked state; 
           [0045]      FIG. 6  is a schematic side view of a second embodiment of a locking unit according to the invention in the unlocked state; 
           [0046]      FIG. 7  is a schematic side view of a third embodiment of a locking unit according to the invention in the unlocked state; 
           [0047]      FIG. 8  is a schematic side view of the third embodiment according to  FIG. 7  in the locked state; 
           [0048]      FIG. 9  is a perspective view of a fourth embodiment of a locking unit according to the invention in the locked state; 
           [0049]      FIG. 10  is another perspective view of the fourth embodiment according to  FIG. 9  in the locked state; 
           [0050]      FIG. 11  is a side view of the fourth embodiment according to  FIG. 9  in the locked state; 
           [0051]      FIG. 12  is a side view of the fourth embodiment according to  FIG. 9  in the locked state without a front connection plate and without a covering; 
           [0052]      FIG. 13  is a section along the line A-A in  FIG. 11 ; 
           [0053]      FIG. 14  is an exploded view of the fourth embodiment according to  FIG. 9 ; 
           [0054]      FIG. 15  is a perspective view of a fifth embodiment of a locking unit according to the invention in the locked state; 
           [0055]      FIG. 16  is a perspective view of a sixth embodiment of a locking unit according to the invention in the locked state; and 
           [0056]      FIG. 17  is a side view of the sixth embodiment according to  FIG. 16  in the locked state. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0057]    In a motor vehicle, there is provided a locking unit  10  for connection of a backrest  3  of a vehicle seat  1 , in particular of a rear seat, to a vehicle structure. In this instance, the backrest  3  is fitted to a seat member  5  so as to be able to pivot from a position for use into a non-use position. 
         [0058]    However, the locking unit  10  can also be used at other locations, for example, in order to fix the seat member  5  of the vehicle seat  1  to the floor structure of the motor vehicle or in a door lock. 
         [0059]    The arrangement of the vehicle seat  1  inside the vehicle and the usual travel direction thereof define the directional indications used below. In this instance, a direction oriented perpendicularly to the ground is referred to below as the vertical direction and a direction perpendicular to the vertical direction and perpendicular to the travel direction is referred to below as the transverse direction. 
         [0060]    A locking unit  10  according to the prior art has a lock housing which comprises a side plate  16  and a covering plate  18 . The base faces of the side plate  16  and the covering plate  18  are constructed to be flat and are arranged in a plane defined by the travel direction and the vertical direction, that is to say, perpendicularly to the transverse direction. The side plate  16  comprises two first bearing holes  13  which are constructed to be circular. The covering plate  18  comprises two second bearing holes  14  which are constructed to be circular. 
         [0061]    There is formed in the side plate  16  and in the covering plate  18  a receiving opening which opens in the direction of a locking bolt  12  in order to receive it for locking. In this instance, the locking unit  10  is fixed to the backrest  3  and the locking bolt  12  is fixed to the vehicle structure here. It is also conceivable for the locking unit  10  to be fixed to the vehicle structure and the locking bolt  12  to be fixed to the backrest  3 . The portion of the locking bolt  12  to be received by the receiving opening extends in this case horizontally in a transverse direction. 
         [0062]    A rotary latch  20  is pivotably supported on a first bearing pin  51  which is fixed to the side plate  16  and the covering plate  18 . To this end, the rotary latch  20  has a rotary latch hole  24  through which the first bearing pin  51  extends. The rotary latch  20  further has a hook-like opening  21  for cooperation with the locking bolt  12 . The rotary latch  20  is pretensioned in the opening direction by means of a first spring  71 . 
         [0063]    The rotary latch  20  has a support contour  22  which partially laterally delimits the hook-like opening  21 . The support contour  22  is constructed to be substantially planar but can also be constructed, for example, to be curved in the manner of a circular arc and concave. In the locked state of the locking unit  10 , the support contour  22  extends approximately in the direction of a second bearing pin  52  which extends parallel with the first bearing pin  51 . 
         [0064]    At the side of the hook-like opening  21  facing away from the rotary latch hole  24 , opposite the support contour  22 , the hook-like opening  21  is laterally delimited by a projection  28  of the rotary latch  20 . The projection  28  has a retention contour  27  which abuts the locking bolt  12  in the locked state of the locking unit  10 . 
         [0065]    The first bearing pin  51  is inserted in a first bearing hole  13  of the side plate  16  and in a second bearing hole  14  of the covering plate  18  and projects perpendicularly from the base faces of the side plate  16  and the covering plate  18 . The first bearing pin  51  consequently extends in this case in a transverse direction. The first bearing pin  51  has a through-opening  55  with a substantially constant inner diameter. 
         [0066]    The second bearing pin  52  is also inserted in a first bearing hole  13  of the side plate  16  and in a second bearing hole  14  of the covering plate  18  and projects perpendicularly from the base faces of the side plate  16  and the covering plate  18 . The second bearing pin  52  consequently also extends in a transverse direction in this case. The second bearing pin  52  has, similarly to the first bearing pin  51 , a through-opening  55  with a substantially constant inner diameter. 
         [0067]    The through-openings  55  of the bearing pins  51 ,  52  are used to receive a fixing means, for example, a screw, by means of which the locking unit  10  is fixed during assembly to the backrest  3  or another structural component of the vehicle seat  1  or the vehicle. To this end, the screws are screwed into fixing holes in the structural component. 
         [0068]    A clamping element  40  is pivotably supported on the second bearing pin  52 . To this end, the clamping element  40  has a clamping element hole  44  which is circular in this case and through which the second bearing pin  52  extends. The clamping element  40  is pretensioned in the direction toward the rotary latch  20  by means of a third spring  73 . 
         [0069]    In the locked state of the locking unit  10 , if the hook-like opening  21  of the rotary latch  20  receives the locking bolt  12 , the clamping element  40  applies a closing moment to the rotary latch  20  as a result of the pretensioning by the third spring  73  as a securing element. To that end, the clamping element  40  has a clamping face  41  which is eccentrically curved relative to the second bearing pin  52  and which is in non-self-locking contact with the support contour  22  of the rotary latch  20 . In this case, the clamping face  41  is constructed to be curved in the manner of a circular arc and convex. 
         [0070]    A catch detent  30  is arranged on the second bearing pin  52  axially beside the clamping element  40  and is also pivotably supported on the second bearing pin  52 , that is to say, so as to be aligned with the clamping element  40 . To this end, the catch detent  30  has a catch detent hole  34  which is circular in this instance and through which the second bearing pin  52  extends. The catch detent  30  is pretensioned in the direction toward the rotary latch  20  by means of a second spring  72 . 
         [0071]    The catch detent  30  has an engaging face  31  which is located adjacent to the clamping face  41  of the clamping element  40 . In the locked state of the locking unit  10 , the engaging face  31  is positioned with spacing from the support contour  22  of the rotary latch  20 . In this case, the engaging face  31  is constructed to be curved in the manner of a circular arc and convex, but may also be planar. 
         [0072]    In this instance, the catch detent  30  is arranged so as to be adjacent to the side plate  16  and the clamping element  40  is in this case arranged so as to be adjacent to the covering plate  18 . The catch detent  30  and the clamping element  40  are connected for entrainment with free travel, for example, by means of a tongue and groove guide or by means of an axially protruding carrier. 
         [0073]    The direction in which the bearing pins  51 ,  52  extend is referred to below as the axial direction. In this instance, in the case of the described fitting situation of the locking unit  10  on the backrest  3  of the vehicle seat  1 , the axial direction extends parallel with the transverse direction. 
         [0074]    In the locked state of the locking unit  10 , the locking bolt  12  is located in the receiving opening which is formed in the side plate  16  and the covering plate  18  and in the hook-like opening  21  of the closed rotary latch  20 . The retention contour  27  of the projection  28  adjoins the locking bolt  12 . The clamping element  40  secures the rotary latch  20  by cooperation of the clamping face  41  with the support contour  22 . The engaging face  31  of the catch detent  30  is slightly spaced apart from the support contour  22  of the rotary latch  20 . 
         [0075]    In order to open the locking unit  10 , the catch detent  30  is pivoted away from the rotary latch  20 , whereby the engaging face  31  of the catch detent  30  moves further away from the support contour  22  of the rotary latch  20 . The catch detent  30  also carries the clamping element  40  as a result of the entrainment connection so that the rotary latch  20  is no longer secured. 
         [0076]    As a result of the pretensioning as a result of the first spring  71 , the rotary latch  20  opens and therefore pivots in an opening direction. Alternatively or additionally to the pretensioning by the first spring  71 , the rotary latch  20  can also be carried by the catch detent  30  or by the clamping element  40  for opening. 
         [0077]    As a result of the pivot movement of the rotary latch  20 , the hook-like opening  21  withdraws from the receiving opening which is formed by the side plate  16  and the covering plate  18  and releases the locking bolt  12 . In this instance, the locking bolt  12  slides along a closure contour  25  which is provided on the rotary latch  20  and moves away from the locking unit  10  counter to the inward pivoting direction. 
         [0078]    If the locking bolt  12  has left the hook-like opening  21 , the locking unit  10  is in the unlocked state. A contour  26  for retaining in the open state which is provided on the rotary latch  20  blocks the catch detent  30  in the position thereof in this case. 
         [0079]    If, in this unlocked state of the locking unit  10 , the locking bolt  12  again moves into the receiving opening which is formed by the side plate  16  and the covering plate  18  and into abutment with the closure contour  25  at the edge of the hook-like opening  21 , the locking bolt  12  presses the rotary latch  20  into the closed position thereof. The clamping element  40  moves as a result of the pretensioning thereof by the third spring  73  along the support contour  22 . In a state carried by the clamping element  40  or as a result of the pretensioning by the second spring  72 , the catch detent  30  which is no longer blocked by the contour  26  for retaining in the open state pivots in the direction toward the rotary latch  20 , wherein the engaging face  31  approaches the support contour  22  of the rotary latch  20 . Afterwards, the locking unit  10  is again in the locked state. 
         [0080]    The rotary latch  20  of the locking unit  10  according to the prior art consequently has a support contour  22 , a closure contour  25 , a contour  26  for retaining in the open state and a retention contour  27 . 
         [0081]      FIG. 5  schematically illustrates a first embodiment of a locking unit  10  according to the invention in the unlocked state. The differences between the first embodiment and the locking unit known from the prior art will substantially be discussed below. 
         [0082]    Instead of a rotary latch, the locking unit  10  according to the first embodiment has a locking detent  80  and a claw  90  which are pivotably supported on the first bearing pin  51  so as to be offset parallel in an axial direction. The locking detent  80  and the claw  90  are connected in a rotationally secure manner to each other in this case. The claw  90  is opposite the catch detent  30  and the clamping element  40  in this case. 
         [0083]    The locking detent  80  and the claw  90  are therefore arranged in separate functional planes. A functional plane extends in this case perpendicularly to the axial direction and has, unlike a mathematical plane, an extent in an axial direction. The catch detent  30  and the clamping element  40  are located in the functional plane of the claw  90 . 
         [0084]    The locking detent  80  has a projection  28  having a retention contour  27 . In the locked state of the locking unit  10 , the retention contour  27  abuts the locking bolt  12 . 
         [0085]    The claw  90  has a support contour  22 , a closure contour  25  and a contour  26  for retaining in the open state. In the locked state of the locking unit  10 , the support contour  22  abuts the clamping face  41  of the clamping element  40  and the engaging face  31  of the catch detent  30  is spaced slightly apart from the support contour  22  of the claw  90 . 
         [0086]    In the unlocked state of the locking unit  10 , the contour  26  for retaining in the open state of the claw  90  abuts the catch detent  30 . During the locking and unlocking of the locking unit  10 , the closure contour  25  of the claw  90  is in contact with the locking bolt  12 . 
         [0087]    In this instance, there is fitted to the covering plate  18  a stop element  60 , which the locking bolt  12  abuts in the locked state of the locking unit  10 . In the locked state of the locking unit  10 , therefore, the locking bolt  12  is clamped between the retention contour  27  of the locking detent  80  and the stop element  60 . 
         [0088]    The stop element  60  is arranged in this instance in the functional plane of the locking detent  80 . In the locked state of the locking unit  10 , the contact locations of the locking bolt  12  are located with the retention contour  27  of the locking detent  80  and with the stop element  60  substantially in a plane which extends perpendicularly to the axial direction. 
         [0089]    During the locking and unlocking of the locking unit  10 , the claw  90  pivots past the stop element  60 . 
         [0090]      FIG. 6  schematically illustrates a second embodiment of a locking unit  10  according to the invention in the unlocked state. The differences between the second embodiment and the locking unit known from the prior art will substantially be discussed below. 
         [0091]    Instead of a rotary latch, the locking unit  10  according to the second embodiment has a locking detent  80 , a clamping claw  92  and an engaging claw  91  which are pivotably supported on the first bearing pin  51  so as to be offset parallel in an axial direction. The locking detent  80 , clamping claw  92  and engaging claw  91  are connected in a rotationally secure manner to each other in this case. The engaging claw  91  is opposite the catch detent  30  and the clamping claw  92  is opposite the clamping element  40  in this case. 
         [0092]    The locking detent  80 , the engaging claw  91  and the clamping claw  92  are therefore arranged in separate functional planes. A functional plane extends in this case perpendicularly to the axial direction and has, unlike a mathematical plane, an extent in an axial direction. The catch detent  30  is located in the functional plane of the engaging claw  91 . The clamping element  40  is located in the functional plane of the clamping claw  92 . 
         [0093]    The locking detent  80  has a projection  28  having a retention contour  27 . In the locked state of the locking unit  10 , the retention contour  27  abuts the locking bolt  12 . 
         [0094]    The engaging claw  91  has a first support contour  22 , a first closure contour  25  and a contour  26  for retaining in the open state. In the locked state of the locking unit  10 , the engaging face  31  of the catch detent  30  is spaced slightly apart from the first support contour  22  of the engaging claw  91 . 
         [0095]    In the unlocked state of the locking unit  10 , the contour  26  for retaining in the open state of the engaging claw  91  abuts the catch detent  30 . During the locking and unlocking of the locking unit  10 , the first closure contour  25  of the engaging claw  91  is in contact with the locking bolt  12 . 
         [0096]    The clamping claw  92  has a second support contour  22  and a second closure contour  25 . In the locked state of the locking unit  10 , the second support contour  22  of the clamping claw  92  abuts the clamping face  41  of the clamping element  40 . 
         [0097]    During the locking and unlocking of the locking unit  10 , the second closure contour  25  of the clamping claw  92  is in contact with the locking bolt  12 . 
         [0098]    In this instance, there is fitted to the covering plate  18  a stop element  60 , which the locking bolt  12  abuts in the locked state of the locking unit  10 . In the locked state of the locking unit  10 , therefore, the locking bolt  12  is clamped between the retention contour  27  of the locking detent  80  and the stop element  60 . 
         [0099]    The stop element  60  is arranged in this instance in the functional plane of the locking detent  80 . In the locked state of the locking unit  10 , the contact locations of the locking bolt  12  are located with the retention contour  27  of the locking detent  80  and with the stop element  60  substantially in a plane which extends perpendicularly to the axial direction. 
         [0100]    During the locking and unlocking of the locking unit  10 , the clamping claw  92  and the engaging claw  91  pivot past the stop element  60 . 
         [0101]      FIG. 7  and  FIG. 8  illustrate a third embodiment of a locking unit  10  according to the invention. The differences between the third embodiment and the locking unit known from the prior art will substantially be discussed below. 
         [0102]    Instead of a rotary latch, the locking unit  10  according to the third embodiment has a locking detent  80  and a claw  90  which are pivotably supported on the first bearing pin  51  so as to be offset parallel in an axial direction. The locking detent  80  and the claw  90  are connected in a rotationally secure manner to each other in this case. The claw  90  is opposite the catch detent  30  and the clamping element  40  in this case. 
         [0103]    The locking detent  80  and the claw  90  are therefore arranged in separate functional planes. A functional plane extends in this case perpendicularly to the axial direction and has, unlike a mathematical plane, an extent in an axial direction. The catch detent  30  and the clamping element  40  are located in the functional plane of the claw  90 . 
         [0104]    The locking detent  80  has a first projection  28  having a first retention contour  27 . In the locked state of the locking unit  10 , the first retention contour  27  of the locking detent  80  abuts the locking bolt  12 . 
         [0105]    The claw  90  has a support contour  22 , a closure contour  25 , a contour  26  for retaining in the open state and a second projection  28  having a second retention contour  27 . 
         [0106]    In the locked state of the locking unit  10 , the support contour  22  of the claw  90  abuts the clamping face  41  of the clamping element  40  and the engaging face  31  of the catch detent  30  is slightly spaced apart from the support contour  22  of the claw  90 . 
         [0107]    In the locked state of the locking unit  10 , the second retention contour  27  of the claw  90  further abuts the locking bolt  12 . 
         [0108]    In the unlocked state of the locking unit  10 , the contour  26  for retaining in the open state of the claw  90  abuts the catch detent  30 . During the locking and unlocking of the locking unit  10 , the closure contour  25  of the claw  90  is in contact with the locking bolt  12 . 
         [0109]    In this instance, there is fitted to the covering plate  18  a stop element  60 , which the locking bolt  12  abuts in the locked state of the locking unit  10 . In the locked state of the locking unit  10 , therefore, the locking bolt  12  is clamped between the first retention contour  27  of the locking detent  80  and the stop element  60 . 
         [0110]    The stop element  60  is arranged in this instance in the functional plane of the locking detent  80 . In the locked state of the locking unit  10 , the contact locations of the locking bolt  12  are located with the first retention contour  27  of the locking detent  80  and with the stop element  60  substantially in a plane which extends perpendicularly to the axial direction. 
         [0111]    During the locking and unlocking of the locking unit  10 , the claw  90  pivots past the stop element  60 . 
         [0112]      FIG. 9  to  FIG. 14  illustrate a fourth embodiment of a locking unit  10  according to the invention. The fourth embodiment is substantially equivalent to the third embodiment in this case. Therefore, the differences between the fourth embodiment and the third embodiment will substantially be discussed below. 
         [0113]    The locking unit  10  according to the fourth embodiment comprises two connection plates  62  which comprise metal in this case and which are constructed to be planar. The two connection plates  62  extend parallel with each other and have two retention holes  64  for receiving two bearing pins  51 ,  52 . 
         [0114]    A locking detent  80  and a claw  90  are surrounded by a common covering  66  which comprises plastics material in this case. The covering  66  covers inter alia the retention contours  27  of the projections  28  of the locking detent  80  and the claw  90 . In the region in which the covering  66  covers the retention contours  27 , the covering  66  is constructed to be curved in a slightly convex manner. 
         [0115]    The covering  66  is curved in such a manner that, in the locked state of the locking unit  10 , the contact locations of the locking bolt  12  with respect to the covering  66  of the retention contours  27  and with respect to the stop element  60  are substantially in a plane which extends perpendicularly to the axial direction. In the case of a slight inclination of the locking bolt  12  to the axial direction which is indicated in  FIG. 13  by an interrupted border, the contact location of the locking bolt  12  with respect to the covering  66  of the retention contours  27  is also displaced in an axial direction only to an insignificant extent. 
         [0116]    The first bearing pin  51 , on which the locking detent  80  and the claw  90  are pivotably arranged, is inserted at both sides in a retention hole  64  of a connection plate  62  and secured at that location. 
         [0117]    A spacer disc  75 , a catch detent  30 , a clamping element  40  and a carrier  76  are pivotably supported beside each other on the second bearing pin  52 . 
         [0118]    The second bearing pin  52  is also inserted at both sides in a retention hole  64  of a connection plate  62  and secured at that location. 
         [0119]    The catch detent  30  is pretensioned in the direction towards the rotary latch  20  by means of a leg spring  77 . The leg spring  77  is wound around the second bearing pin  52  and is supported with a spring end on one of the connection plates  62  and on the catch detent  30 . 
         [0120]    The clamping element  40  is connected to the carrier  76  in a rotationally secure manner. A tension spring  78  is fixed to the locking detent  80  and the carrier  76 . The locking detent  80  is pretensioned in an opening direction and the clamping element  40  is pretensioned in the direction toward the rotary latch  20  by means of the tension spring  78 . 
         [0121]    There is provided, in this instance clip-fitted, on the catch detent  30  an engaging sleeve  35  which comprises plastics material in this case and which serves to fix an actuation rod which is not illustrated in this case. 
         [0122]    The stop element  60  is fixed to the connection plate  62  which is adjacent to the locking detent  80 . Optionally, a side plate  16  and a covering plate  18  form a lock housing for the locking unit  10 . 
         [0123]      FIG. 15  illustrates a fifth embodiment of a locking unit  10  according to the invention. The fifth embodiment is substantially equivalent to the fourth embodiment in this instance. 
         [0124]    Instead of a tension spring, there is provided a compression spring  79  which is fixed between the claw  90  and the clamping element  40 . The locking detent  80  is pretensioned in the opening direction and the clamping element  40  is pretensioned in the direction toward the rotary latch  20  by means of the compression spring  79 . 
         [0125]    An actuation rod  37  is fixed to the engaging sleeve  35  provided on the catch detent  30 . 
         [0126]      FIG. 16  and  FIG. 17  illustrate a sixth embodiment of a locking unit  10  according to the invention. The sixth embodiment is substantially equivalent to the fourth embodiment in this instance. 
         [0127]    A retention opening  69  is provided in the two connection plates  62  in addition to the two retention holes  64 . The retention openings  69  are each constructed as a slot. A retention bolt  58  is inserted into the two retention openings  69 . The retention bolt  58  is constructed to be hollow-cylindrical and has a gripping opening  59 . 
         [0128]    In this instance, the retention bolt  58  has a cross-section which is different from the circular shape and which is adapted to the slot-like form of the retention openings  69 . The gripping opening  59  also has an elongate cross-section which is different from the circular shape. 
         [0129]    In this instance, the second bearing pin  52  is constructed to be solid and therefore does not have any through-opening. 
         [0130]    In order to fix the locking unit  10 , there are provided two screws which are inserted in the through-opening  55  of the first bearing pin  51  and in the gripping opening  59  of the retention bolt  58 . The screws are screwed into fixing holes in the structural component. 
         [0131]    As a result of the slot-like cross-section of the gripping opening  59  of the retention bolt  58 , the spacing of the two screws with respect to each other is variable. It is thereby possible to adapt the locking unit  10  to different gauges of the structural component. 
         [0132]    The spacing of the center axes of the fixing holes with respect to each other is referred to in this case as the gauge. 
         [0133]    Alternatively, the retention bolt  58  is constructed similarly to the first bearing pin  51  and has a circular cross-section and a gripping opening  59  with a circular cross-section. In order to adapt the locking unit  10  to different gauges, the retention bolt  58  can be displaced within the slot-like retention openings  69 . The spacing of the two screws which are inserted in the through-opening  55  of the first bearing pin  51  and in the gripping opening  59  of the retention bolt  58  is also thereby variable. 
         [0134]    An actuation rod  37  is fixed to the engaging sleeve  35  which is provided on the catch detent  30 . 
         [0135]    The features disclosed in the above description, the claims and the drawings may be significant both individually and together for implementing the invention in the various embodiments thereof. 
         [0136]    While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.