Abstract:
For a cabriolet vehicle with a convertible top hatch which can be moved between a cover position and an open position for selectively covering and opening a convertible top compartment and with a roll bar which can be moved between a lowered position and a protective position and which can be coupled to the convertible top hatch for joint movement, a convertible top hatch transmission part is provided which transfers the driving force to the convertible top hatch which can be disengageably coupled to a roll bar movement part that produces movement apparatus of the roll bar so that roll bar is movement can be produced, simultaneously with motion of the convertible top hatch, that is in a different direction from that of the convertible top hatch during at least one segment of the motion of the convertible top hatch.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to a cabriolet vehicle with a convertible top hatch which can be moved between a cover position and an open position for selectively covering and opening a convertible top compartment and with a roll bar which can be moved between a lowered position and a protective position and which can be coupled to the convertible top hatch for joint movement.  
           [0003]    2. Description of Related Art  
           [0004]    A generic cabriolet vehicle is known from German Patent DE 197 14 104 C1. In the vehicle shown there, the convertible top hatch can be coupled directly to the roll bar via a journal to swing together, which journal is movably attached to the hatch in the transverse direction of the motor vehicle. The roll bar is made C-shaped, with two legs which are coupled to the motor vehicle sides and a cross brace which joins the two legs.  
           [0005]    Since the roll bar is generally swung into its protective position from the vehicle rear to the vehicle front around an axis which runs in the transverse direction of the vehicle, the convertible top hatch must likewise execute such a swing motion as a result of the coupling to the roll bar which is shown in German Patent DE 197 14 014 C1. Aligned in its open position, the roll bar forms a barrier which must be overcome by the convertible top during the stowage process. This requires complex sequences of motion in space and time by the convertible top, the convertible top hatch and the roll bar.  
           [0006]    The disadvantage in the known embodiment is that the motion of the convertible top hatch is fixed in terms of type and direction by the roll bar: It must swing jointly with the roll bar in the same direction and with the same direction of rotation.  
         SUMMARY OF THE INVENTION  
         [0007]    The primary object of the present invention is to develop a cabriolet vehicle such that the convertible top can be retracted into the convertible top compartment of the vehicle and extended from it using simple sequences of motion.  
           [0008]    By selectively coupling a convertible top hatch transmission part to the roll bar movement part, in place of the convertible top hatch itself, the convertible top hatch can be moved with greater independence from the roll bar. Movement of the convertible top into the convertible top compartment (retraction) or out of it (extension) can be enabled more easily than in the past. On the one hand, the roll bar can be raised when the convertible top is being retracted or extended so that an opening of the convertible top compartment that is as large as possible can be used for this purpose. On the other hand, the roll bar can be located in its lowered position over the opening of the convertible top compartment so that it does not occupy any volume in the vehicle interior.  
           [0009]    The convertible top hatch transmission part can be connected directly or indirectly to the convertible top hatch. It is sufficient if driving force for moving the convertible top hatch is routed via it to the hatch.  
           [0010]    Otherwise, in this application, the mobility of the part between two positions should also encompass the mobility of the part into any intermediate position between the two positions. The roll bar movement part is also called only the “movement part” below.  
           [0011]    Although the movement part in accordance with the invention can be the roll bar itself, in one especially economical alternative, the movement part, for reasons of greater independence of movement from the convertible top hatch and the roll bar, is preferably a part which is coupled to the roll bar for transfer of force and/or motion, such as, for example, the connecting rod of a driving or kinematic mechanism.  
           [0012]    Increased safety of the vehicle passengers can also be ensured according to one development of the invention in that the roll bar, in its lowered position, is coupled or can be coupled to a safety drive which provides the driving force for moving the roll bar into the protective position.  
           [0013]    Likewise, it is possible for the coupling of the roll bar movement apparatus to the convertible top hatch transmission part to take place manually by the driver. This can be done in a structurally simple manner in that the convertible top hatch transmission part can be coupled to the roll bar movement part by a movable lock element. However, the driver, in particular, need not be concerned to which part the roll bar movement part is coupled, if the convertible top hatch transmission part is coupled to the roll bar movement part in a normal driving situation. As a result of the mobility of the lock element, the coupling between the roll bar movement part and the convertible top hatch transmission part can be released at any time as required. A normal driving situation, in contrast to the emergency situation, is defined as any normal traffic situation including a parking situation, in which there is no need to trigger the roll bar for safety reasons.  
           [0014]    However, when the coupling of the convertible top hatch transmission part to the roll bar movement part as the convertible top hatch is being opened is produced by the motion of the convertible top hatch transmission part, the existing coupling between the convertible top hatch transmission part and the roll bar movement part need not be released first in order to move the roll bar into the protective position. This offers increased passenger safety.  
           [0015]    In one preferred-embodiment, the cabriolet vehicle comprises a convertible top hatch transmission part which can be moved between a first end position which is assigned to the cover position and a second end position assigned to the open position, a roll bar movement part which can be moved between a first end position assigned to the lowered position and a second end position which is assigned to the protective position, and a safety drive transmission part which can be moved between a first end position which corresponds to the force preparation position of the safety drive for the roll bar and a second end position which corresponds to the activation position of the safety drive. The aforementioned function can be obtained, for example, in that the transmission parts and the roll bar movement part can be moved at least some distance with the same type of motion and the same direction of motion in movement in the direction from its first end position to the second end position. Different types of motion can be rotation and/or translation. It is noted that motion of the same type and direction need begin neither in the first end position nor end in the second end position of one of the parts.  
           [0016]    Joint motion of the movement part with one of the transmission parts at a time can be easily and economically achieved by there being on the convertible top hatch transmission part and/or on the safety drive transmission part one driving means each for driving the roll bar movement part in the motion of the respective transmission part in the direction of the second end position. In one especially simple case the driving means can be made as a mechanical stop. The roll bar movement part can be pushed by the mechanical stop for joint motion by one of the transmission parts. This has the advantage that the safety drive transmission part, which generally triggers suddenly, can so to speak “overtake” the more slowly moving convertible top hatch transmission part, and thus, in an especially simple and reliable manner, can release the coupling of the motion of the roll bar movement part to the convertible top hatch transmission part at any time and can establish this coupling to the safety drive transmission part at any time.  
           [0017]    However, in this type of coupling of motion, first of all, there is no coupling possibility for motion which sets the roll bar back into its lowered position. This can be achieved, for example, by the aforementioned lock element.  
           [0018]    According to one advantageous development of the invention, the roll bar-convertible top hatch system can be made such that the lock element is made on the roll bar movement part. In this case, the roll bar movement part can be made such that the lock element can be moved between preferably positive engagement to the safety drive transmission part and a preferably positive engagement to the convertible top hatch transmission part. Thus, with the two transmission parts, secure coupling engagement can be selectively achieved by which there is also a reset possibility of the roll bar into the lowered position.  
           [0019]    One prerequisite for automatic engagement of the lock element to the respective transmission part which entrains the movement part can be accomplished in that there is at least one gear mechanism on the lock element by which movement of the roll bar movement part and/or of the safety drive transmission part can be stepped up into motion which moves the lock element.  
           [0020]    In one especially simple embodiment, the lock element can be made such that at least one angular surface is provided on the lock element, preferably for each transmission part an assigned angular surface. The angular surface is made as a gear mechanism, the surface normal of at least one angular surface having a component which is parallel to the direction of motion of the lock element and a component parallel to the direction of motion of the roll bar movement part out of the first end position.  
           [0021]    Then, the transmission parts can be made such that the safety drive transmission part and/or the roll bar movement part has one acting surface each or can be coupled to one which is made for interaction with at least one angular surface of the lock element in order to thus cause the motion which moves the lock element. The active surface can be used, for example, as a slideway surface for the angular surface of the lock element. The part which has the acting surface can also be held in the roll bar movement part and can be coupled to one of the transmission parts or can be actuated by one of the transmission parts.  
           [0022]    Reliable and permanent engagement of the lock element to one of the transmission parts can be implemented by there being a fixing means which fixes the lock element during motion of the roll bar movement part in the respective engagement position.  
           [0023]    The fixing means can be made as a mechanical control especially easily and reliably, for example, such that the fixing means comprises a host of slide surfaces which run in the direction of motion of the roll bar movement part. These slide surfaces can be formed, for example, by a system of projections and grooves which fit into one another or by projections with contact surfaces which run parallel to one another and in the direction of motion of the movement part. The slide surfaces, of which there can be one on the lock element and another mounted on the body, can adjoin one another during the motion of the roll bar movement part, such that the body-mounted slide surface prevents displacement of the lock element out of its instantaneous engagement position.  
           [0024]    Alternatively or in addition, it can be provided that the fixing means is formed by spring elements which tension the lock element into its engagement position.  
           [0025]    To increase passenger safety in an emergency situation, the roll bar-convertible top hatch system can be developed such that there is a pull-back blocking part which, when the safety drive transmission part is not triggered, is locked in the pull-back release position in which it allows motion of the roll bar movement part in the direction toward the first end position, and which is unlocked by motion of the safety drive transmission part from its first end position in the direction to its second end position for movement into the pull-back blocking position in which it does not allow movement of the roll bar movement part in the direction to the first end position.  
           [0026]    The motion of the pull-back blocking part when it is unlocked can be easily ensured by the pull-back blocking part being locked against pre-tensioning of the spring towards the pull-back blocking position in the pull-back release position.  
           [0027]    A structurally simple and thus economical implementation of unlocking of the pull-back blocking part by the safety drive transmission part can be achieved by the safety drive transmission part being coupled in its first end position to the pull-back blocking part in its pull-back release position via a force transmission means, such as gearing or a rod.  
           [0028]    The aforementioned advantageous effects can also be obtained on a generic motor vehicle by the roll bar and the convertible top hatch each being connected to a driving device which can be coupled to one another via a common control, and the convertible top hatch and the roll bar can be driven by the control and the respectively assigned driving devices into motion in directions which are different at least in segments. A space and/or time interval of joint motion of the convertible top hatch and the roll bar can be considered “in segments”.  
           [0029]    In the cabriolet vehicle in accordance with the invention, thus a process for stowing and unloading a cabriolet convertible top from a convertible top compartment which can be covered with a convertible top hatch is possible which is characterized in that at least in one segment of motion of the convertible top hatch, a roll bar is moved simultaneously with it in a direction of motion which is different from the direction of motion of the convertible top hatch.  
           [0030]    The invention is explained by way of example with reference to the attached drawings using preferred embodiments. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0031]    FIGS.  1  to  3  show a first embodiment of an arrangement in accordance with the invention with a convertible top hatch transmission part, a roll bar movement part and a safety drive transmission part in a first end position, an intermediate position and a second end position, respectively,  
         [0032]    FIGS.  4  to  6  show three positions of a second embodiment of an arrangement in accordance with the invention with a convertible top hatch transmission part, a roll bar movement part and a safety drive transmission part, and  
         [0033]    [0033]FIGS. 7 a ,  7   b  to  10   a ,  10   b  show graphic and schematic depictions of four different embodiments of a roll bar for a motor vehicle in accordance with the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]    [0034]FIG. 1 shows a body-mounted guide rail  10  in which the convertible top hatch transmission part  12 , the roll bar movement part  14  and the safety drive transmission part  16  are accommodated to be able to move in the directions of the double arrows F. The convertible top hatch transmission part  12  is connected via other connecting rods (not shown) to a movement drive (not shown) and a convertible top hatch (not shown). In the roll bar movement part, an axle journal  18  is accommodated which runs essentially in the transverse direction of the motor vehicle and which is pivotally coupled to a leg of the roll bar which is not shown in this figure.  
         [0035]    The safety drive transmission part  16  is connected to a tensioned spring  20  as the safety drive for rapid motion of the roll bar out of its lowered position into the protective position. The safety drive transmission part  16  is held in position via a locking pin  22 .  
         [0036]    [0036]FIG. 1 shows the two transmission parts  12 ,  16  and the movement part  14  in their first end position, in which the convertible top hatch is closed, the roll bar is in its lowered position and the spring  20  is in its force readiness position.  
         [0037]    On a lengthwise end area, the convertible top hatch transmission part has a projection  24  which, as the driving means, is used to drive the movement part  14  in the case of motion of the convertible top hatch transmission part  12  to the right in FIG. 1.  
         [0038]    Likewise, on the end area of the safety drive transmission part  16  facing the spring  20 , there is a projection  26  as the driving means. The projection  26  adjoins the end face  15  of the movement part  14 . The projection  24  and the projection  26  project towards one another from their respective transmission parts  12 ,  16 , but in their projecting lengths are dimensioned such that they can slide past one another.  
         [0039]    In addition, in the movement part  14 , there is a lock element  28  which can be moved in the direction of motionwhich is essentially orthogonal to the guidance direction F. This lock element  28  is made larger in its direction of motion S than the movement part  14  in this direction. Therefore, an end area of the lock element  28  always projects relative to the side boundary surfaces  30 ,  32  of the movement part  14 , which surfaces run in the guidance direction F. In the example shown in FIG. 1, an end area of the lock element  28  projects into an engagement recess  34  of the safety drive transmission part  16 . An engagement recess  36  of the convertible top hatch transmission part  12  which is made mirror symmetrically to the part  16  is offset in the direction of the spring  20  so that the convertible top hatch transmission part  12  blocks the motion of the lock element  28  in the direction of the convertible top hatch transmission part  12  in the FIG. 1 position.  
         [0040]    In its end areas, the lock element  28  has angular surfaces  38 ,  40 . These angular surfaces  38  and  40  are aligned such that their surface normal has a component in the direction of motion of the roll bar movement part  14  out of the first end position and a component in the direction of motion S of the lock element  28 . The angular surface  38  interacts with a co-acting surface  42  which is made complementary to the angular surface  38  and which forms a part of boundary of the engagement recess  34 . The acting surface  44  of the engagement recess  36  is assigned to the angular surface  40 . When the convertible top hatch transmission part  12  moves with driving of the movement part  14 , when the lock element  28  is engaged with the engagement recess  34  of the safety drive transmission part  16 , the pairing of the angular surface  38  and the acting surface  42  causes the lock element  28  to engage the engagement recess  36  by the pairing of the angular surface  38  and the acting surface  42 . This situation is shown in FIG. 2.  
         [0041]    The analogous situation applies to the pairing of the angular surface  40  and the acting surface  44  in the motion of the safety drive transmission part  16  when the lock element  28  is first engaged to the engagement recess  36  of the convertible top hatch transmission part  12 .  
         [0042]    A projection  46  is formed on the lock element  28  which interacts with the fixing strip  48  of the guide rail  10 . The projection  46  and the fixing strip  48  are dimensioned in their thickness with consideration of the possible displacement path of the lock element  28  such that the projection  46  in the case of engaging the lock element  28  with the engagement recess  34  with the first slide surface  50  slides along the first contact surface  52  of the fixing strip  48 . However, if the lock element  28  is engaged to the engagement recess  36 , the second slide surface  54  of the projection  46  which is opposite the first is in contact with the second contact surface  56  of the fixing strip  48 . The fixing strip  48  and the projection  46  which adjoins prevents the lock element  28  from disengaging from the respective transmission part.  
         [0043]    It is shown in FIG. 2 how the movement part  14  is entrained by the convertible top hatch transmission part  12  as it moves out of the first end position.  
         [0044]    It is shown in FIG. 3 how the safety drive transmission part  16 , under the action of the spring  20 , is moved out of its first end position, and in doing so, entrains the movement part  14 . Such a case occurs when the roll bar is suddenly triggered as a result of an extremely critical traffic situation and is moved into its protective position.  
         [0045]    FIGS.  4  to  6  show a second embodiment which is alternative to the first embodiment shown in FIGS.  1  to  3 . The component parts of the first and second embodiment which correspond to one another are provided in FIGS.  4  to  6  with the same reference numbers, but increased by 100. The second embodiment is described only to the extent that it differs form the first embodiment, otherwise reference is made expressly to the description of FIGS.  1  to  3 . Otherwise, in FIGS.  4  to  6 , a connecting rod which is connected to the roll bar  160  and joints which are assigned to it are labeled according to the embodiment shown in FIG. 9.  
         [0046]    In FIG. 4, the convertible top hatch transmission part  112 , the roll bar movement part  114  and the safety drive transmission part  116  are in their respective first end position. In it, the safety drive transmission part  116  is held by a locking hook  122  which can swivel around an axis which runs in the transverse direction of the vehicle. The locking hook  122  can, like the locking pin  22 , be raised by a lifting magnet  123  so that the safety drive transmission part  116  is triggered for movement in the direction of its second end position, i.e., in FIG. 4 to the right. In order to prevent unintentional triggering of the safety drive, the locking hook  122  can be additionally tensioned by a spring (not shown) into its position shown in FIG. 4. The spring  120  of the safety drive is supported in a body-mounted spring bearing  108 .  
         [0047]    As shown in FIG. 4, the roll bar movement part  114  lies, in the direction of motion of the safety drive transmission part  116  towards its second end position, in front of the transmission part  116  so that its end face pointing towards the movement part  114  forms the driving means  126 .  
         [0048]    No driving means is made on the convertible top hatch transmission part  112  in this embodiment. Rather, the transmission part  112  is coupled to the movement part  114  for joint motion by the lock element  128  which is engaged to the engagement recess  136 . The lock element  128  is pre-tensioned by two springs  129  into the engagement position shown in FIG. 4. If, at this point, the convertible top hatch transmission part  112  is driven to move the convertible top hatch (not shown), as a result of the described coupling, the roll bar movement part  114 , and thus the roll bar  160 , are moved at the same time.  
         [0049]    On the roll bar movement part  114 , there is a decoupling mechanism  170 . It comprises the acting surface  142  which interacts with the angular surface  138  of the lock element  128  and as a result of the pre-tensioning force of the springs  129 , adjoins it. On the end area of the roll bar movement part  114  which faces toward the safety drive transmission part  116 , an actuating element  172  of the decoupling mechanism  170  projects relative to the end face  115  of the movement part  114  pointing toward the transmission part  116 . Preferably, but not necessarily, it adjoins the end face  126  of the transmission part  116 . The end faces  115 ,  126  are spaced apart from one another at a distance which is chosen such that, when the safety drive transmission part  116  is triggered, it first pushes the actuating element  172  into the movement part  114 . Thus, the interaction of the acting surface  142  with the angular surface  138  pulls the lock element  128  out of the engagement opening  136  against the action of the springs  129  and releases the coupling to the convertible top hatch transmission part  112 . The distance of the end faces  115 ,  126  therefore follows essentially from the penetration depth of the lock element  128  into the engagement recess  136  and the angular position of the surfaces  138 ,  142  with respect to the direction of motion S of the lock element.  
         [0050]    Then, as soon as the end face  126  adjoins the end face  115  of the movement part  114 , the movement part  114 , which has been decoupled from the transmission part  112 , is driven by the transmission part  116  to move. The roll bar  160  is suddenly moved from its lowered position into the protective position. As in the first embodiment, here, the safety drive transmission part  116  can also release the coupling between the convertible top hatch transmission part  112  and the roll bar movement part  114 , not only in its first end position, but in each intermediate position, and drives the roll bar movement part  114  itself.  
         [0051]    On the bottom of the roll bar movement part, teeth  180  are formed such that the tooth flanks facing toward the second end position are positioned with a comparatively flat angle against the direction of motion F, while the tooth flanks facing toward the first end position of the movement part  114  are located essentially orthogonally to the direction of motion F. Furthermore, in a recess in the guide rail  110 , there is a pull-back blocking part  182  which, on its side facing towards the movement part  114 , has teeth  184  which are made complementary to the teeth  180  of the movement part  114 . The pull-back blocking part  182  is locked by a pin  188  against the tension force of two springs  186  in the pull-back release position. In the pull-back release position, the teeth  184  are positioned such that the movement part  114  can slide away over it without the teeth  180 ,  184  coming into contact with one another.  
         [0052]    The pin  188  is held against the pre-tensioning force of a spring (not shown) in its position which locks the pull-back blocking part  182 . A transmission rod  190 , which is formed from a forcing lever  192 , and a rocker arm  194  prevents the pin  188  from being decoupled from the position shown in FIG. 4 by spring force. The free end of the rocker arm  194  adjoins one side of the safety drive transmission part  116 . The pin  188  is thus prevented from moving to unlock the pull-back blocking part  182  until the transmission part  116  has moved to its second end position insofar as the rocker arm  194  no longer adjoins its side and can turn clockwise.  
         [0053]    [0053]FIG. 5 shows the position of the roll bar-convertible top hatch system similar to that of FIG. 2. To move the convertible top hatch, the convertible top hatch transmission part  112  is moved and driven in the direction of the double arrow F, more precisely to the right in FIG. 5. By the lock element  128 , which is inserted into the engagement recess  136  of the transmission part  112 , the roll bar movement part  114  is moved by the convertible top hatch transmission part  112  at the same time.  
         [0054]    [0054]FIG. 6 shows a situation similar to FIG. 3, i.e., the safety drive for the roll bar  160  has been triggered. The hook  122  has been raised by the lifting magnet  123 , whereupon the safety drive transmission part  116  has been driven by the spring  120  in the direction of the double arrow F, more accurately to the right in FIG. 6. First, the actuating element  172  is pressed into the movement part  114  in the direction of motion of the transmission part  116 . As a result of the consequent displacement of the acting surface  142 , the lock element  128  is pulled out of the engagement opening  136  by the interaction of the angular surface  138  and the acting surface  142  in the direction of the double arrow S, more accurately downward in FIG. 6. Then, the end faces  115 ,  126  engage one another, whereupon the roll bar movement part, driven by the transmission part  116 , is moved into its second end position shown in FIG. 6. In this position, the movement part  114  adjoins the end stop  196 .  
         [0055]    After the safety drive transmission part  116  has been moved to the right out of its first end position so far that the free end of the rocker arm  194  is no longer supported by the transmission part  116 , the pin  188  is withdrawn from the engagement recess  189  in the pull-back blocking part  182  by the spring (not shown) which pre-stresses it. The pull-back blocking part  182  thereupon moves, driven by the springs  186 , in the direction of the double arrow S, more accurately upward in FIG. 6, and now projects beyond the slide plane of the guide rail  110 . Based on the described execution of the teeth  180 ,  184  in the movement part  114  and in the pull-back blocking part  182 , motion of the movement part  114  toward the second end position is possible but movement in the direction toward the first end position, however, is hindered by the tooth flanks which are almost orthogonal relative to the direction of motion F and which adjoin one another. For releasing the roll bar  160  from the protective position shown in FIG. 6, first the pull-back blocking part  182  must first be moved into its pull-back release position again and locked there by the pin  188 . The pull-back block which is shown prevents the roll bar  160  from being able to be forced back into the lowered position by the kinetic energy of the impact of a vehicle in overturning.  
         [0056]    In FIGS.  7  to  10 , different embodiments of a roll bar  60  for use in a motor vehicle in accordance with the invention are shown. Here FIGS. 7 a  to  10   a  each show connecting rod diagrams of the respective roll bar  60 , while FIGS. 7 b  to  10   b  each show schematic perspectives of the roll bar.  
         [0057]    In all of FIGS.  7  to  10 , the roll bars are labeled  60 , the cross brace of the roll bar  60  is labeled  60   a  and the leg of the roll bar  60  which leads from the cross brace to the coupling point on the vehicle body is labeled  60   b . In FIGS. 7 a  to  10   a , moreover, the trajectory of the cross brace  60   a  which is always projected there onto one point when the roll bar moves is labeled  62 .  
         [0058]    In FIGS.  7  to  10  the joints are labeled with single-digit numbers with apostrophes and the connecting rods connected to the joints are labeled with single-digit numbers in a circle.  
         [0059]    [0059]FIG. 7 shows the simplest case of a roll bar which is coupled directly by its legs  60   b  to the vehicle body via a joint  1 ′. The trajectory  62  of the cross brace  60   a  when the roll bar is moved corresponds to a circle in the projection of FIG. 7 a.    
         [0060]    In FIG. 8, the leg  60   b  of the roll bar  60  is formed by the connecting rods  2 ,  4  which are rigidly connected to one another. The free lengthwise end of the leg  60   b  is connected via the joint  2 ′ to the driving connecting rod  1  which in turn is coupled via a joint  1 ′ to the vehicle body. In addition, the leg  60   b , for guidance of the motion of the roll bar  60 , is connected to the connecting rod  3  at the coupling point  3 ′ in the area of the lengthwise center of the leg  60   b  which is, however, pushed slightly towards the joint  2 ′; the rod  3  is coupled on its other lengthwise end via a joint  4 ′ to the vehicle body.  
         [0061]    As the trajectory  62  in FIG. 8 a  shows, the advantage of this construction is that the cross brace  60   a  first moves essentially vertically up out of the rest position of the roll bar  60 , by which, for example, head supports can be easily bypassed.  
         [0062]    A similar action is achieved with the construction shown in FIG. 9. The construction shown in FIG. 9 corresponds essentially to the one shown in FIG. 8, but the connecting rod  1  is replaced by a slideway which runs in the lengthwise direction of the vehicle. Otherwise, reference is made to the description of FIG. 8 for the explanation of FIG. 9. The slideway shown in FIG. 9 a  can be executed in detail, for example, in the manner shown in FIGS.  1  to  3  or also in the manner shown in FIGS.  4  to  6 .  
         [0063]    [0063]FIG. 10 corresponds essentially likewise to the embodiment shown in FIG. 8; reference is made expressly to its description here. In addition, in the alternative shown in FIG. 10, the joint  3 ′ is coupled to a connecting rod  6  which, in turn, is connected at the joint  5 ′ to the connecting rod  5  which, in turn, is connected to the vehicle body via a joint  6 ′. In addition, the coupling point  1 ′ of the driving connecting rod  1  on the body, with reference to the coupling point  4 ′ of the connecting rod  3 , is chosen to be elsewhere than in FIG. 8 a ; this leads to the trajectory  62  of the cross brace  60   a  which is shown in FIG. 10 a  as being essentially vertical.  
         [0064]    The features of the invention disclosed in the above description, in the drawings and in the claims can be important to the accomplishment of the invention both individually and also in any combination.