Abstract:
The invention describes a fifth-wheel coupling ( 1 ) having a fifth-wheel coupling plate ( 2 ) on which is arranged an entry opening ( 4 ) for a king pin ( 5 ). Provision is made of an at least single-part locking device ( 100 ) for fastening the king pin ( 5 ) and of a fixing element which engages on the locking device, which fixing element can be moved from a locking position into an open position and vice versa. In addition to the locking system, a securing device ( 15 ) with a blocking element ( 40, 400 ) is provided, which blocking element ( 40, 400 ) can be moved from a rest position into a blocking position and vice versa, wherein the blocking element ( 40, 400 ) projects into the entry opening ( 4 ) at least in the blocking position.

Description:
BACKGROUND 
       [0001]    The invention relates to a fifth-wheel coupling having a fifth-wheel coupling plate, on which an entry opening for a kingpin is disposed, having an at least one-part locking device for fixing the kingpin in place, and having a fixation element that engages on the locking device, which element can be moved from a locking position into an open position and vice versa. 
         [0002]    Utility vehicles generally consist of a tractor vehicle and one or more towed trailers. In the case of such a truck and trailer combination, one speaks of a motor truck with trailer; in the case of an articulated truck and trailer combination, one speaks of a tractor unit and a semi-trailer. 
         [0003]    Parked and non-driven vehicle parts can be secured against theft by means of mechanical devices, in each instance. The motorized parts of the truck are also generally secured against break-in and theft, for example by means of engine immobilizers or alarm systems. When the two vehicle parts are coupled with one another, a certain anti-theft protection exists for the entire articulated truck and trailer combination, by way of these systems, since uncoupling them is only possible by means of a relative movement of the two vehicle parts with regard to one another. 
         [0004]    However, the number of thefts in which the driven vehicle is separated from the trailer or semi-trailer and the latter is subsequently stolen is constantly increasing, in spite of the current technical aids. It is therefore desirable to make available devices and systems that prevent the semi-trailer from being uncoupled in unauthorized manner, or to at least make this process so difficult that the attempt to uncouple them appears unlikely to succeed, right from the start. 
         [0005]    From WO 03/043838 A2, an anti-theft device for fifth-wheel couplings is known, which comprises an activation device having a disabling pin. The fifth-wheel coupling has a locking hook having a securing latch that can be activated by hand, with a traction rod, by way of a linkage. 
         [0006]    The anti-theft device provides that the disabling pin is moved either into the movement path of the securing latch or into the movement path of the components of the linkage for activating the securing latch, so that the securing latch cannot be moved from its closed position into an open position. 
         [0007]    The anti-theft device has a receiver by way of which the activation device can be controlled. The anti-theft device is coupled with a Global Positioning System of the tractor vehicle. If the vehicle is not moving on the planned route, this is recognized by the GP system, and a signal for arming the anti-theft device is sent to the receiver, whereupon the disabling pin is brought into the disabling position. 
         [0008]    According to another embodiment, the anti-theft device can also be controlled via the Internet, by means of an externally disposed PC, by way of the on-board computer of the tractor vehicle. 
         [0009]    Manipulation attempts at the fifth-wheel coupling are also recognized by the anti-theft system, which thereupon automatically goes into the armed state and thus also into the locking position. 
         [0010]    In WO 03/044627 by the same applicant, other security systems are described, where among other things, the driver&#39;s authorization is checked by way of entry of a code. In the case of non-observance of or in the case of deviation from the travel route, intervention in the vehicle functions takes place automatically. 
         [0011]    WO 2005/028290 A1 discloses a fifth-wheel coupling having an anti-theft device, in which a disabling pin engages directly on the locking hook and fixes it in place. 
         [0012]    By way of the traction rod, this locked state can be cancelled out. Then, separation of tractor vehicle and semi-trailer by force cannot be prevented, because the locking hook can be rotated into the open position if the tractor and semi-trailer combination is suddenly moved forward, damaging or even destroying the anti-theft device. 
         [0013]    The anti-theft device comprises a control device in the driver&#39;s cabin of the tractor vehicle, into which a numerical code can be input for release. Furthermore, sensors and displays are connected with the control device, to monitor the fifth-wheel coupling. 
         [0014]    DE 195 16 101 A1 describes an anti-theft device for a coupled semi-trailer. For protection of a semi-trailer coupled to a tractor vehicle, by means of uncoupling it, the fifth-wheel coupling has a lock by way of which an axially movable tappet is controlled. The tappet engages directly on the locking element of the locking hook, if the latter is in the blocking position. The placement of the anti-theft device is selected in such a manner that the tappet is at most impacted by pressure. Blocking of the manually activated locking hook has the advantage that in the case of a shock stress or overload of the manual activation, the elements of the manual activation that are smaller in cross-section will break, and in any case, the locking elements of the locking hook will remain intact. All the parts of the anti-theft device are subjected to pressure stress in the event of an unlocking attempt using force, so that relatively small cross-sections offer the required functional security. 
         [0015]    Anti-theft devices generally engage on the locking system of the fifth-wheel coupling and are intended to disable the locking system so that it cannot be opened. The anti-theft device itself does not offer any mechanical protection that could prevent uncoupling of the semi-trailer. This is due, among other things, to the fact that the anti-theft system or the components that disable the locking system are not configured to be sufficiently stable and strong to prevent opening of the locking system by force. 
         [0016]    It is therefore the task of the invention to equip a fifth-wheel coupling with a security device that can be used together with an anti-theft device, if applicable, and that guarantees additional security against unauthorized uncoupling of the semi-trailer. 
       SUMMARY 
       [0017]    This task is accomplished with a fifth-wheel coupling characterized in that a security device having a blocking element is provided, which element can be moved from a rest position into a blocking position, and vice versa, that the blocking element projects into the entry opening at least in the blocking position, and that the blocking element is fixed in place in the blocking position when the fixation element is in the open position in unauthorized manner. 
         [0018]    The blocking element of the additional security device forms a mechanical barrier that blocks outward movement of the kingpin even if, for example, an anti-theft device has been shut off by force and/or opening of the locking device has been carried out in unauthorized manner. An additional mechanical barrier is created with the blocking element, which barrier is configured to be so stable that is withstands forcible manipulation. 
         [0019]    Fixation of the blocking element in its blocking position is advantageous for preventing the blocking element from being moved back into its rest position by means of unauthorized activation of the locking system; in this rest position, a potential thief might be able to expose the entry opening of the fifth-wheel coupling after all, in order to allow moving the kingpin out. 
         [0020]    Preferably, the blocking element is disposed within the fifth-wheel coupling in covered manner, and thus is not accessible from the outside. Preferably, it cannot be activated manually. 
         [0021]    The locking device can be a pivoting locking hook or it can consist of two or more components, which engage around the kingpin in the locked position. 
         [0022]    Depending on the configuration of the locking device, a locking latch or a locking clamp can be provided as the fixation element that fixes the locking device in place in its locking position, and thereby blocks it. 
         [0023]    According to a first embodiment, the fixation element is a locking latch and the blocking element interacts with the locking latch. Preferably, the blocking element contacts the locking latch and is coupled with the movement of the locking latch in the event of unauthorized activation of the locking system. If the locking latch is moved into the open position in unauthorized manner, the blocking element follows it and is moved into its blocking position. 
         [0024]    Preferably, the blocking element is disposed to lie opposite the locking latch. In this connection, the locking latch and the blocking element are preferably disposed on a common axis. If the locking latch is disposed on one side of the entry opening, for example, the blocking element is provided on the other side. In this case, the tips of locking latch and blocking element lie opposite one another. 
         [0025]    Preferably, the blocking element is a blocking latch. A blocking latch has the advantage that it is a stable mechanical component, which can counter unwanted removal of the kingpin with sufficient mechanical resistance. 
         [0026]    It is advantageous if the blocking latch can be displaced in the same direction as the locking latch. When the locking latch is moved into the open position, the blocking latch is moved into the entry opening and assumes the position of the locking latch there. The movement sequence is simplified and the space requirement for the locking element, i.e. the locking latch is kept low. 
         [0027]    The blocking latch is preferably releasably attached to the locking latch. The blocking latch is attached to the locking latch when the latter is moved in unauthorized manner. The blocking latch is pulled into the blocking position by the locking latch. The blocking latch comes free from the locking latch if the locking latch is activated in authorized manner. The blocking latch then remains in its rest position. 
         [0028]    Preferably, the tip of the blocking latch is releasably attached to the tip of the locking latch. 
         [0029]    In order to create this releasable attachment, it is provided, according to an embodiment, that the locking latch and/or the blocking latch has/have at least one magnet. The strength of the magnet(s) is designed in such a manner that on the one hand, the locking latch can pull the blocking latch with it, and on the other hand, the blocking latch can come free from the locking latch if the locking latch is moved in authorized manner and the blocking latch is fixed in place in its rest position. 
         [0030]    According to another embodiment, the locking latch and the blocking element can have engagement means that engage into one another and can also be released from one another again, if necessary. 
         [0031]    Engagement projections and engagement hooks are preferably provided as engagement means. 
         [0032]    Another embodiment provides that the blocking element has a first spring device that presses the blocking element against the locking latch in the locking position of the locking latch. If the locking latch is retracted in unauthorized manner, the blocking latch follows it automatically and assumes the position of the locking latch in the entry opening. 
         [0033]    The blocking element can preferably be fixed in place in its rest position. Fixation of the blocking element in the rest position is necessary so that the locking latch can come free from the blocking element in the event of authorized activation. 
         [0034]    The means for fixation and release of the blocking element preferably comprise a first activation device having blocking means and having at least one actuator. The actuator is preferably an electrically, pneumatically, or hydraulically activated actuator. 
         [0035]    A disabling pin or a pawl can be provided as disabling means. 
         [0036]    Preferably, the disabling pin can be displaced perpendicular to the movement direction of the blocking element. 
         [0037]    In order for the disabling means to be able to effectively fix the blocking element in place, preferably at least a first recess is provided, into which the disabling means can engage. 
         [0038]    In order to be able to switch the activation device in the desired manner, it is connected with a control device. The control device can have a data entry station so that commands, numerical codes, or the like, for example, can be input. The operator can establish whether opening of the locking latch is taking place in authorized or unauthorized manner, by way of the control device. 
         [0039]    According to a special embodiment, the control device can be connected with a monitoring device, for example a device for monitoring the locking state of the fifth-wheel coupling. Depending on the locking state, this information can be used for switching the security device. 
         [0040]    The monitoring device can also be an anti-theft device or have such a device, in order to detect unauthorized opening of the locking hook. Such an anti-theft device can engage on the locking hook, in conventional manner, and detect unauthorized opening of the locking hook. The anti-theft device therefore preferably has a device on the locking hook, for example having a disabling pin, which is connected with a display device and/or control device in the driver&#39;s cabin. For example, this can be an anti-theft device as described in WO 2005/028290 A1. 
         [0041]    Preferably, the blocking element is adjustable in its rest position. An adjustment can become necessary if the locking latch demonstrates wear phenomena and the contact between the locking latch and the blocking element no longer exists in the manner planned. 
         [0042]    Preferably, a second activation device having disabling means and an actuator for fixing the locking latch in place in its locking position are provided. This second activation device can be an integral part of a separate anti-theft device, for example, or it can also be connected to the control device. This makes it possible not only to activate the security device by way of the control device, but also, as an additional measure, to disable the locking latch. 
         [0043]    According to another embodiment, the blocking element is disposed at a distance from the locking device and the fixation element. In this connection, the blocking element does not interact with the locking latch. This embodiment has the advantage that the function of the locking mechanism is not influenced by the security device. All the functions of the locking mechanism are retained. 
         [0044]    Preferably, the blocking element is disposed within the second half of the entry opening. This second half of the entry opening designates the last half of the entry opening in the entry direction. In this region, the entry opening has already narrowed to such an extent that a blocking element that is not overly large is already sufficient for blocking the entry opening. 
         [0045]    Preferably, the blocking element is held in the blocking position by means of a second spring device, and can be moved to release the entry opening, counter to the force of the second spring device, by a kingpin that is moving in or out. The blocking element can be fixed in place in the blocking position. 
         [0046]    In this embodiment, the blocking element constantly projects into the entry opening, so that the blocking position and the rest position coincide. Blocking of the entry opening is achieved in that the blocking element is also fixed in place in this blocking position, and cannot be moved by a kingpin that is moving out. In this manner, security in the event of unauthorized opening of the locking system of the kingpin is assured. 
         [0047]    In this embodiment, as well, it is advantageous if the blocking element is a blocking latch. This blocking latch is preferably disposed so that it can move preferably perpendicular to the longitudinal axis of the entry opening. 
         [0048]    As in the first exemplary embodiment, an activation device is provided to fix the blocking element in place and to release it, which device comprises disabling means and at least one actuator. This activation device is preferably a disabling device. This disabling device is preferably configured in such a manner that after the kingpin has moved in, the blocking element is automatically disabled in its blocking position. 
         [0049]    The disabling device comprises a disabling piece and a third spring device that holds the disabling piece in the disabling position. 
         [0050]    Preferably, the disabling piece has an actuator that moves the disabling piece out of the disabling position into a release position, counter to the force of the third spring device. 
         [0051]    Preferably, the blocking element has a pawl that interacts with the disabling piece. This pawl fixes the disabling piece in place counter to the force of the third spring device. If the blocking element is moved backward by a kingpin that is moving in, counter to the force of the second spring device, the disabling piece, which is biased by way of the third spring device, is released by means of the pawl, so that the disabling piece can be pressed against the blocking element. The disabling piece is preferably moved perpendicular to the movement direction of the blocking element. 
         [0052]    It is advantageous if the actuator is also connected with the control device, in order to be able to control the actuator in the desired manner. 
         [0053]    Preferably, at least one of the activation devices is disposed on the fifth-wheel coupling so as to be visible from the outside. Supplementally, the activation device can have an optical and/or an acoustical device. These measures are supposed to indicate the presence of a security device to potential thieves and thus discourage them from attempting to steal the semi-trailer. 
         [0054]    The activation device or the activation devices is/are disposed in a housing, in each instance, where the housing is screwed onto the top of the fifth-wheel coupling plate, according to one embodiment. Loosening of the screws is not possible when the semi-trailer is coupled on. 
         [0055]    The housing can also be welded or riveted onto the fifth-wheel coupling plate. Preferably, cast iron, cast steel, high-strength light metal, or high-strength plastic is provided as the material for the housing, in order to prevent the housing from being destroyed by the effects of force. 
         [0056]    In particular, coils, cylinders, servo motors, or hydraulic drives are suitable as actuators. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0057]    Exemplary embodiments of the invention will be explained in greater detail in the following, using the drawings. These show: 
           [0058]      FIG. 1  a schematic representation of a tractor vehicle, 
           [0059]      FIG. 2  the bottom view of a fifth-wheel coupling, 
           [0060]      FIGS. 3 to 9  enlarged details of the bottom view of the fifth-wheel coupling shown in  FIG. 2 , to explain different positions of locking latch and blocking element, as well as to explain different embodiments, 
           [0061]      FIG. 10  a schematic representation of the bottom view of a fifth-wheel coupling according to another embodiment, 
           [0062]      FIGS. 11 to 14  enlarged representations of the security device in four different positions. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0063]    In  FIG. 1 , a tractor vehicle  10  is shown, which carries a fifth-wheel coupling  1 . The fifth-wheel coupling  1  is equipped with an additional security device, of which only a first activation device  50  is shown in  FIG. 1 , which device is connected with a control device  70  in the driver&#39;s cabin  12  by way of an electrical line  53   a.    
         [0064]    The activation device  50  is affixed on the underside of the fifth-wheel coupling plate  2  in such a manner that it can be seen from the outside. The additional optical device  58  can blink, for example, in order to signal that the security device  15  is active. By means of these measures, potential thieves are supposed to be deterred right from the start from attempting to uncouple the semi-trailer (not shown here) from the tractor vehicle  10 . 
         [0065]    The security device  15  can be turned on and off by way of the control device  70 . A corresponding data entry device, for example a code entry device, can be integrated for this purpose. 
         [0066]    The control device  70  can also be connected with a monitoring device  72 , which is connected with the locking system of the fifth-wheel coupling by way of an electrical line  53   b  (see dot-dash line) and determines the locking state of the fifth-wheel coupling. This can be an anti-theft device  74  having a device  75   a  on the locking hook and having a display and/or control device  75   b , which device forms the monitoring device  72 , for example, or is integrated into it. This information can be utilized to activate or deactivate the security system  15  in the corresponding manner, as provided, by way of the control device  70 . 
         [0067]    Such a monitoring device can also be an anti-theft device or have an anti-theft device, which also engages on the locking system of the fifth-wheel coupling and disables the locking system of the fifth-wheel coupling when it is armed. This information can also be utilized to activate or deactivate the security device  15 . 
         [0068]    In  FIG. 2 , the bottom view of the fifth-wheel coupling  1  is shown. To move a kingpin  5  in, the fifth-wheel coupling plate  2  has an entry opening  4 . 
         [0069]    The fifth-wheel coupling  1  has a locking system  18  that comprises a locking device  100  in the form of a locking hook  102  (see also  FIG. 3 ), a locking latch  20 , and a lifting mechanism  30  having a traction rod  32  as well as having levers  34  and  36 . In its locking position, the locking hook  102  engages around the kingpin  5  that has been moved in. Parts of the locking system are covered by the cover frame  6 , so that the interaction of the individual components of the locking system is not evident. The position of the individual components corresponds to that in  FIG. 5 . 
         [0070]    In order to move the locking latch  20  into its locking position, the traction rod  32  is displaced, with the movement being transferred to the locking latch  20  by way of levers  34  and  36 . 
         [0071]    Opposite the locking latch  20 , a blocking element  40  in the form of a blocking latch and as an integral part of the security device  15  is disposed, the method of functioning of which device will be explained in detail in connection with  FIGS. 3 to 9 . 
         [0072]    Behind the locking latch  40 , an adjustment screw  76  is shown, with which the locking latch can be adjusted in its rest position. 
         [0073]    In  FIG. 3 , an enlarged detail view is shown, which shows the interaction of locking latch  20  and blocking latch  40 . 
         [0074]    The locking hook  102 , which forms the locking device  100 , can be pivoted about a stud  108  and has two shanks  104  and  106 , which engage around the kingpin  5  in the locking position. In order to fix the locking hook  102  in place in its locking position, the locking latch  20  is displaced in front of the locking hook in the direction of the arrow, so that the locking latch  20  comes to lie in the entry opening  4 . In this connection, the shank  106  of the locking hook  102  lies against the locking latch  20 , so that the locking hook  102  is prevented from rotating out of place. 
         [0075]    On the other side, the blocking latch  40  lies opposite the locking latch  20 . In the embodiment shown here, the locking latch  20  is situated on the one side of the entry opening  4 , and the blocking latch  40  is situated on the other side of the entry opening  4 . At its front end  41 , the locking latch  40  possesses a connecting element  42 , which engages, in clamping manner, into a corresponding recess  22  on the front end  21  of the locking latch  20 . A releasable connection of the blocking latch  40  with the locking latch  20  is created by way of the connecting element  42  and the first recess  22 . 
         [0076]    On one of its two longitudinal sides, the blocking latch  40  has two recesses  44  and  46 . In the rest position of the blocking latch  40  shown here, a disabling pin  56  of a first activation device  50  engages into the first recess  44 . This disabling pin  56  is moved by means of an actuator  54 . This actuator  54  is disposed in a housing  52 . The actuator is connected with the control device  70  by way of an electrical connection line  53  (see  FIG. 1 ). 
         [0077]    This activation device  50  is disposed in such a manner that the disabling pin  56  moves perpendicular to the movement direction of the blocking latch  40 . In the rest position of the blocking latch  40 , the disabling pin  56  engages into the first recess  44  and thereby disables the blocking latch  40 . 
         [0078]    If the locking latch  20  is moved to the left, in the direction of the arrow, to open the locking hook in authorized manner, as shown in  FIG. 4 , the locking latch  20  comes free from the blocking latch  40  and thereby releases the entry opening  4 . The locking hook can be pivoted into the open position, so that the kingpin  5  can move out. 
         [0079]    If, however, the locking latch  20  is being activated in unauthorized manner, the activation device  50  is switched in such a manner that the disabling pin  56  does not engage into the first recess  42  [sic—should be  44 ]. The disabling pin  56  is in a retracted position and is held in this position. The blocking latch  40  is therefore freely movable and is dragged along by the locking latch  20 , so that the blocking latch  40  is pulled into the blocking position. In this blocking position, the front end with the connecting element  42  is in the entry opening  4  of the fifth-wheel coupling, as can be seen in  FIG. 5 . Only in this position does the locking latch  20  come free from the blocking latch  40 . 
         [0080]    In order to prevent the blocking latch  40  from being pushed back into its rest position when the locking latch  20  is pushed back, the disabling pin  56  has been moved out, so that it engages into the second recess  46 . In this way, the blocking latch  40  is fixed in place in its blocking position. In this blocking position, the locking hook can only be moved within limits, where the locking hook does not release the kingpin. This ensures that in the event of unauthorized activation of the locking latch  20 , uncoupling of the semi-trailer and the tractor vehicle  10  cannot take place. This is guaranteed by the blocking latch  40 , which is in the blocking position. 
         [0081]    Only by means of a release by way of the control device  70  is the disabling pin  56  retracted from the recess  46 , so that the blocking latch  40  can be pushed back into its rest position according to  FIG. 4 . 
         [0082]    In  FIG. 6 , another embodiment is shown, which comprises a second activation device  60  that has an actuator  64  having a disabling pin  66  in a housing  62 . Disabling of the locking latch  20  is made possible by way of the disabling pin  66 . The disabling pin  66  projects into a corresponding recess  24  of the locking latch  20 , if the latter is in the locking position shown in  FIG. 6 . If forcible opening of the locking latch  20  were to take place, first of all the locking latch  20  is fixed in place in its position. In the event of forcible opening, the disabling pin  66  could certainly be damaged, and this is detected by way of a corresponding device. In this case, a corresponding signal is issued to the control device  70 , which then retracts the disabling pin  56  so that the blocking latch  40  is released and is freely movable. This makes it possible for the blocking latch  40  to be moved into its locking position in the event of a displacement of the locking latch  20 , as has been described in connection with  FIGS. 3 to 5 . 
         [0083]    In  FIG. 7 , a special embodiment of the releasable connection of blocking latch  40  and locking latch  20  is shown. In the connecting element  42  of the blocking latch  40 , there is a magnet  48  that projects slightly with regard to the connecting element  42 , and interacts with the locking latch  20 . 
         [0084]    Another embodiment is shown in  FIG. 8 , where the locking latch  20  has an engagement projection  26  that interacts with an engagement hook of the blocking latch  40 . The two engagement means are designed in such a manner that in the event of fixation of the blocking latch  40 , the locking latch  20  can come free from the blocking latch  40 . At the same time, the engagement means are designed in such a manner that it is possible for the locking latch  40  to be carried along if the blocking latch  40  is released and the locking latch is moved into its open position in unauthorized manner. 
         [0085]    In  FIG. 9 , another embodiment is shown, in which the blocking latch  40  is activated by means of a spring device  43 . In the position shown in  FIG. 9 , the locking latch  20  is in its open position, so that the locking hook  102  can move into its open position. Because of the fact that the locking latch  40  is pushed into the entry opening  4  by means of the spring device  43  that engages at its back, the locking hook  102  is disabled, so that it cannot open completely. 
         [0086]    In  FIG. 10 , another embodiment is shown, in which a blocking latch  400  is disposed at a distance from the locking system  18  of the fifth-wheel coupling  1 . The entry opening  4  extends from the outer delimitation line  112  all the way to the locking system  18 , where the line  114  marks the center. The blocking latch  400  is situated in the rear half, between the center line  114  and the locking system  18 , in the entry direction. The blocking latch  400  is situated to the side of the entry opening  4  and is disposed in displaceable manner, so that it can also be displaced perpendicular to the longitudinal axis  110  of the entry opening  4 . 
         [0087]    The blocking latch  400  (see  FIG. 11 ) possesses a set-back, so that a counter-bearing surface  406  is formed, which lies against the side wall  424  of the fifth-wheel coupling plate  2 . 
         [0088]    The blocking latch  400  is guided on its longitudinal side  408  by a guide rib  420 , and on the opposite side  409  by a rib  425  of the side wall  424 , and is situated in a chamber  500  that has another smaller chamber  502  on the side, in which a second spring device  80  is disposed. 
         [0089]    This spring device  80  supports itself on a guide rib  422  and presses the blocking latch  400  into the position shown in  FIG. 11 . 
         [0090]    The blocking latch  400  furthermore has a pawl  90  that has a stud  98  at its top, which stud is mounted to rotate in the fifth-wheel coupling. The blocking latch  400  has a stud  94  that engages into an oblong hole  92  of the pawl  90 , so that the pawl can be displaced in its longitudinal direction. 
         [0091]    The front end of the pawl  90  possesses a pawl tip  96  that engages on a projection  85  of a disabling piece  84  of a disabling device  82 . The disabling piece  84  is also disposed so as to be movable. The movement direction of the disabling piece  84  is perpendicular to the movement direction of the blocking latch  400 . 
         [0092]    The disabling piece  84  possesses a third spring device  86 , which moves the disabling piece  84  in the direction of the blocking latch  400 . The disabling piece  84  is held in its open position by means of the pawl  90 , so that the blocking latch  400  is movable and can be moved counter to the force of the second spring device  80 . 
         [0093]    In  FIG. 12 , the entry process of the kingpin  5  is shown. The kingpin  5  engages on the entry slant  410  of the tip  404  of the blocking latch  400  and moves the blocking lever  400  in the direction of the arrow, i.e. into the interior of the chamber  500 , counter to the force of the second spring device  80 . As this happens, the pawl  90  is activated by the stud  94 , and pivoted about the pin  98 , so that the pawl tip  96  comes free from the projection  85  of the disabling piece  84 . This has the result that the disabling piece  84  is pressed against the blocking latch  400  by way of the third spring device  86 . 
         [0094]    In the representation shown in  FIG. 12 , the disabling piece  84  lies against a corner of the blocking latch  400  with its slant  87 . As soon as the kingpin  5  has been moved completely in, the second spring device  86  presses the blocking latch  400  into the entry opening  4 , so that the blocking latch  400  assumes its blocking position. As a result, the disabling piece  84  is released from the blocking latch  400 , so that the disabling piece  84  can move into the free space  504  behind the blocking latch  400 , until it lies against the projection  426  of the guide rib  422 . 
         [0095]    A movement of the blocking latch  400  opposite the direction of the arrow shown in  FIG. 13  is no longer possible, because the disabling piece is disposed between the rib  422  and the blocking latch  400 . In this way, securing is guaranteed, preventing the kingpin  5  from being moved out again. 
         [0096]    If the kingpin is supposed to be released, the disabling piece  84  is displaced in the direction of the arrow, counter to the effect of the third spring device  86 , by means of an actuator  88 , as shown in  FIG. 14 , so that the blocking latch  400  is freely movable once again. When the kingpin  5  is moved out, it moves the blocking latch  400  in the direction of the arrow, counter to the effect of the second spring device  80 , where the pawl  90  is pivoted, at the same time, in such a manner that the pawl tip  96  engages into the projection  85  of the disabling piece  84  and disables it in its rest position. 
       REFERENCE SYMBOL LIST 
       [0000]    
       
           1  fifth-wheel coupling 
           2  fifth-wheel coupling plate 
           4  entry opening 
           5  kingpin 
           6  cover frame 
           10  tractor vehicle 
           12  driver&#39;s cabin 
           15  security device 
           18  locking system 
           20  locking latch 
           21  front end 
           22  first recess 
           24  second recess 
           26  engagement projection 
           30  lifting mechanism 
           32  traction rod 
           34  lever 
           36  lever 
           40  blocking element 
           41  front end 
           42  connecting element 
           43  first spring device 
           44  first recess 
           46  second recess 
           48  magnet 
           49  engagement hook 
           50  first activation device 
           52  housing 
           53   a  line 
           53   b  line 
           54  actuator 
           56  disabling pin 
           58  optical and/or acoustical device 
           60  second activation device 
           62  housing 
           64  actuator 
           66  disabling pin 
           70  control device 
           72  monitoring device 
           74  anti-theft device 
           75   a  device on locking hook 
           75   b  display and/or control device 
           76  adjustment screw 
           80  second spring device 
           82  disabling device 
           84  disabling piece 
           86  third spring device 
           87  slant 
           88  actuator 
           90  pawl 
           92  oblong hole 
           94  stud 
           96  pawl tip 
           98  stud 
           100  locking device
         102  locking hook     104  shank     106  shank     110  longitudinal axis     112  outer delimitation line     114  center line     400  blocking element     404  tip     406  counter-bearing surface     408  longitudinal side     409  side     410  entry slant     420  guide rib     422  guide rib     424  side wall     425  rib     426  projection     500  chamber     502  chamber     504  free space