TECHNICAL FIELD 
     The instant invention relates to a lever arm coupling for detachably connecting hose lines, comprising a first connection part and a second connection part, wherein the second connection part encompasses a receptacle housing comprising a receptacle space, on which at least one lever arm is supported so as to be moved pivotably about a pivot bolt, which defines a pivot axis, with a pressure application section reaching through a radial opening of a housing wall, so that the lever arm can be brought from a locking position via a pressure release position into a release position and back, wherein the pressure application section positionally fixes a front side of the first connection part in the locking position or releases it in the pressure release position and in the release position, respectively. 
     STATE OF THE ART 
     Lever arm constructions for detachably connecting hose lines, in which liquids, solid materials and gases are conveyed, are known in the technology. 
     A first connection part, which is connected to a first line, is detachably attached in a receptacle housing, wherein a second line is connected to the second connection part. At least one lever arm, which engages with a pressure application section through a radial opening in the receptacle housing, allows for the fixation of the first connection part within the receptacle housing of the second connection part in an unlocking position. The pressure application section of the lever arm engages with a pressure surface into a peripheral groove on the first connection part in a clamping manner. Typically, provision is made for two lever arms, which are pivotably supported on opposite sides of the receptacle housing so as to engage with a receptacle space of the receptacle housing. 
     The known lever arm couplings release the first connection part from the second connection part into a release position of the lever arms. A liquid-tight connection of the first connection part and of the second connection part is attained in the locking position, so that the lever arm coupling connects the first hose line and the second hose line so as to form a seal in a pressure range of up to 10 bar. 
     In the past, the attainable tightness of the lever arm coupling as well as the operating safety of the lever arms was improved. EP0615090 describes a device, which attains the securing of the position of the lever arms in the locking position, wherein an unintentional activation of the lever arms is made impossible. An accidental, unintentional complete separation of the coupling parts of the lever arm coupling is made impossible by means of this device, so that accidents with pressurized lever arm couplings can be avoided. 
     EP 0615090 discloses a lever arm coupling, which encompasses a two-stage locking process, wherein the lever arm coupling can be brought from a release position, in which the first connection part can be inserted into and removed from the receptacle housing, into a locking position. However, an uncontrolled escape of the excess pressure and a deflection of the lever arms can take place in response to the disengagement of a pressurized connection of the first hose line and of the second hose line, as soon as the clamping connection between the pressure surface of the lever arm and a clamping side of the peripheral groove has been disengaged. The first connection part is pressed out of the receptacle housing and the conveyed liquid or the gas escapes suddenly due to the excess pressure in the first and second hose line. The lever arms are moved suddenly into the release position by means of the relative movement of the first connection part to the second connection part, which can lead to injuries to the operating personnel and to the destruction of the lever arm coupling. The closing accuracy and the tightness of the lever arm coupling deteriorate during operating when the lever arms deflect in response to a repeated decoupling. 
     In the first step of the disengagement of the two connection parts, the current solutions have the effect that a rubber seal located therebetween is displaced and that pressure relief or ventilation does not take place at all. In response to the complete separation, the pressure is thus still present and the two parts shoot away from one another with a corresponding risk of injury. 
     Lever arm couplings of the state of the art encompass a locking position, in which a first connection part is detachably connected to a second connection part so as to form a seal. The separation of the first and second connection part takes place in a release position, in which the first connection part can be removed from the receptacle housing of the second connection part in the direction of the longitudinal axis of the insertion section. Lever arm couplings comprising a two-stage locking process have the above-mentioned disadvantages. 
     ILLUSTRATION OF THE INVENTION 
     It is the object of the instant invention to create a lever arm coupling, which ensures a controlled position change of the lever arms and a controlled pressure release or ventilation during the unlocking process of the lever arm coupling in the case of a connection of a first connection part to a second connection part, with said connection being pressurized. 
     A lever arm coupling comprising the features of patent claim  1  fulfills this object and additionally the prevention of an undesired displacement of the lever arms as well as the guarantee that a pressure release or a ventilation takes place. 
     Further advantageous embodiments are disclosed in the dependent claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred exemplary embodiment of the object of the invention will be described below in context with the appended drawings. 
         FIG. 1  shows a top view onto a section of a lever arm coupling according to the invention in locking position, wherein one half of a receptacle housing of a second connection part comprising a lever arm is illustrated in a partially sectional view. 
         FIG. 2  shows a top view according to  FIG. 1 , wherein the illustrated lever arm coupling is in a pressure release/ventilation position or in a still sealing position. 
         FIG. 3  shows a top view according to  FIG. 2 , wherein the illustrated lever arm is in a release position and a detention cam of a securing disk engages with a clamping side of the peripheral groove. 
         FIG. 4  shows a top view according to  FIG. 3 , wherein the illustrated lever arm is in a release position and the pressure application section as well as the securing disk releases the first connection part. 
         FIG. 5  shows a top view onto a securing disk. 
         FIG. 6   a  shows a top view onto a lever arm, while 
         FIG. 6   b  shows a side view of a lever arm. 
         FIG. 7   a  shows a section of a further embodiment of a second connection part in the form of a sealing plug, while 
         FIG. 7   b  shows a pure sectional illustration of the connection part according to  FIG. 7   a , which is rotated by 90°. 
         FIG. 8  shows a top view onto a further embodiment of the securing disk. 
     
    
    
     DESCRIPTION 
     A part of a lever arm coupling  1 , which couples a first connection part  4  of a first hose line  2  to a second connection part  5  is shown in  FIG. 1 . The second connection part  5  illustrated herein encompasses a receptacle housing  50  comprising a ring-shaped housing wall  501 , in the receptacle space  500  of which the first connection part  4  can be inserted with an insertion section  40 . The insertion section  40  encompasses a peripheral groove  42 , which is defined by a rear side  41  and a front side  43 . The first connection part  4  is detachably connected to the second connection part  5  by means of a sealing ring  502  in a liquid and gas-tight manner. 
     The invention is defined herein using the example of a second connection part  5  in the manner of a sealing plug, wherein it is naturally also possible for a further hose line to be connected to the second connection part  5 . 
     The lever arm  11  encompasses a cylindrical hole  111  in a pressure application section  112 . A pivot bolt  51 , which is integrally molded on the receptacle housing  50  or which is attached thereto so as to be capable of being detached, engages through the cylindrical hole  111 , whereby the lever arm  11  is operatively attached to the second connection part  5  and thus to the receptacle housing  50  in the area of the pressure application section  112  so as to engage with the housing wall  501  through a radial opening  52 . The lever arm  11  can be pivoted about a pivot axis, which runs through the pivot bolt  51 , relative to the receptacle housing  50 . The pressure application section  112 , which engages through the radial opening  52  in the receptacle housing  50 , encompasses a pressure surface  114 , which can be operatively connected to a front side  43  of the insertion section  40 . 
     In a locking position of the lever arm  11 , the pressure application section  112  engages with the peripheral groove  42  of the first connection part  4 , which is inserted into the receptacle housing  50 . Pressed onto the front side  43 , the pressure surface  114  can thereby be clamped, whereby a detachable positive liquid-tight and/or gas-right connection of the first connection part  4  is attained in the receptacle housing  50  of the second connection part  5 . In the locking position, a linear movement of the first connection part  4  relative to the second connection part  5  is thus made impossible. Provision is made for a locking stop  55  for defining the movement of the lever arm  11  in the locking position on the second connection part  5 . 
     From the locking position, the lever arm  11  can be brought into a release position, in which the first connection part can be detached from the second connection part  4 ,  5 . A pressure release or ventilation of the first hose line  2  takes place in response to the movement of the lever arm  11  into the release position, because the liquid and/or gas-tight connection between the first connection part  4  and the second connection part  5  is separated. The instant patent application generally refers to pressure release, which represents a ventilation, for example, when gaseous media are used. The release position and a pressure release or ventilation connected thereto can take place as soon as a release point  116  located on the pressure application section  112  releases the first connection part  4 . The shape of the pressure application section  112  and the positioning of the release point  116  determine at which deflection of the lever arm  11  a pressure release or ventilation can take place. 
     In the release position, the lever arm  11  is oriented such that the pressure surface  114  of the pressure application section  112  is not engaged with or in contact with the peripheral groove  42  or with another part of the insertion section  40 , which is embodied in a tapered manner. The maximum deflection of the lever arm  11  is defined by a release stop  53  on the second connection part  5 , which can be seen in  FIG. 4 . 
     When the lever arm  11  and thus the pressure application section  112  is moved from the locking position in the direction of the release position, the pressure surface  114  releases the first connection part  4  within the receptacle housing  50 , starting at the release point  116 , so that the insertion section  40  can be removed from the receptacle housing  50 . 
     To avoid an uncontrollable pressure release or ventilation and an unintentional linear movement of the first connection part  4  out of the receptacle housing  50 , a securing disk  10  is initially supported in a movable manner on the pivot bolt  51  in an approximately parallel direction to the pressure application section  112  of the lever arm  11 . This securing disk  10  can be pivoted independent on the lever arm  11 . A recess  115  comprising a recess surface  117 , which interacts with the securing disk  10 , is recessed at the lever arm  11 . 
     The securing disk  10  crosses an elongated hole  101 . The outer shape of the elongated hole  101  illustrated herein of a preferred embodiment of the securing disk  10  encompasses a curved course, wherein a linear shape would also be possible. A detention cam  104  is embodied such that this detention cam  104  is embodied so as to be able to project into the peripheral groove  42  when the securing disk  10  is supported on the pivot bolt  51 . In addition to the detention cam  104 , which interacts with the front side  43 , a defining cam  102  and a carry-along cam  105  are also integrally molded on the securing disk  10 . 
     In the locking position according to  FIG. 1 , the pressure surface  114  holds the front side  43  of the first connection part  4 , while the detention cam  104  projects into the peripheral groove  42  without an effect and without touching the first connection part  4 . 
     In the event that the lever arm  11  is moved out of the locking position, the pressure surface  114  looses the contact to the front side  43 , so that the first connection part  4  is released and can be moved linearly out of the receptacle housing  50 . As can be seen in  FIG. 2 , the detention cam  104  engages with the peripheral groove  42  and touches the front side  43 . 
     Due to the linear movement of the first connection part  4  out of the receptacle housing  50 , the securing disk  10  is pivoted about the pivot axis by means of the contact of the detention cam  104  with the front side  43  in the clockwise direction into a first direction B until the defining cam  102  strikes a pressure release stop  54  on the second connection part  5 . 
     A force P, which is caught by the recess surface  117  by means of the positive contact with the outer contour  106 , acts on the securing disk  10 , so that no forces act on the lever arm  11  in a second direction A in counter-clockwise direction or in the direction B in clockwise direction and so that the lever arm  11  is thus not unintentionally moved in the directions A or B in response to the pressure release or ventilation. The securing disk  10  cannot be rotated in clockwise direction A according to  FIG. 2 , because the outer contour  106  cannot be guided along the recess surface  117  and because the defining cam  102  is held by the pressure release stop  54 . The securing disk  10  is supported by the recess surface  117 . A ventilation or a pressure release or a pressure maintaining, respectively, can take place for the first time in the position illustrated in  FIG. 2 . 
     The force P impedes the movement of the securing disk  10  such that the securing disk  10  can only be rotated minimally in clockwise direction. In response to an upward pivoting of the lever arm  11  in the direction A according to  FIG. 2 , the recess surface  117  of the pressure application section  112  moves across a flat area  107 , which follows the outer contour  106  of the securing disk  10 . The securing disk  10  is then no longer connected to the recess surface  117  in a positive manner, so that a linear displacement of the securing disk  10  occurs, as can be seen in  FIG. 3 . 
     The carry-along cam  105  prevents the unintentional rotation of the securing disk  10  in counter-clockwise direction into the receptacle housing  50 , in that the carry-along cam  105  strikes against the release stop  53 . The carry-along cam  105  also prevents an uncontrolled rotation of the securing disk  10  in clockwise direction, because the carry-along cam  105  strikes against the recess surface  117  on the lever arm  11 . 
     In response to a small pivoting of the lever arm  11  in counter-clockwise direction, the securing disk  10  can be moved out of the receptacle housing  50 , determined by the embodiment of the elongated hole  101  away from the longitudinal axis of the receptacle housing  50 . 
     In this secured pressure release position, the linear movement of the first connection part  4  out of the receptacle housing  50  is made impossible by the interaction of the detention cam  104  on the front side  43  so as to press thereon, by the interaction of the defining cam  102  with the pressure release stop  54  and the stop of the carry-along cam  105  on the lever arm  11 . 
     The first connection part  4  cannot carry out a linear movement approximately parallel to the longitudinal axis of the first connection part  4 . The interaction of the detention cam  104  with the front side  43  of the peripheral groove  42  makes an unintentional movement impossible and a displacement of the lever arms  11  does not take place in response to the ventilation. 
     To dissolve the secured, pressure-released position, the lever arm  11  is further pivoted in counter-clockwise direction, as is illustrate din  FIG. 4 . The lever arm  11  carries along the securing disk  10  in response to the pivoting movement in counter-clockwise direction. 
     The recess  115  integrally molded on the pressure application section  112  carries along the carry-along cam  105  and thus the securing disk  10  and the securing disk is pivoted about the pivot axis such that the detention cam  104  releases the front side  43  of the peripheral groove  42 . A release surface  103  of the securing disk  10  faces the first connection part  4 . The release surface  103  is thereby located approximately parallel to the outer surface of the first connection part  4  and the first connection part  4  can thus be removed from the receptacle housing  50 . 
     In response to the pivot movement into the release position, the pressure application section  112  of the lever arm  11  carries along the carry-along cam  105  of the securing disk  10  until the carry-along cam  105  abuts on the release stop  53 . So that the securing disk  10  can be guided from the secured pressure release position into the release position by means of the carry-along cam  105 , the design of the outer contour  106  of the securing disk  10  must be embodied such that the recess surface  117  of the recess  115  of the pressure application section  112  can move across the outer contour  106 . 
     A fixation of the lever arm  11  in the locking position can be reached as in EP0615090, for example, wherein securing pins comprising corresponding tension elements, which are supported in a resilient manner, can be inserted into the lever arms  11 . These securing pins can be inserted into recesses on the second connection part, which are provided for this purpose, and can be secured at that location, whereby an unintentional opening of the lever arms  11  is made impossible. 
     Lever arm couplings according to the state of the art, which do not comprise the securing disk  10  described herein, encompass a sudden and uncontrollable movement of the lever arm from the locking position to the release position when the first hose pipe  2  encompasses an excess pressure. The lever arm coupling  1  illustrated herein, which encompasses a secured pressure release or pressure maintaining position between a locking position and a release position, prevents a sudden unintentional pressure release or ventilation. 
       FIG. 3  illustrates the secured pressure release or pressure maintaining position of the lever arm  11  or of the first connection part  4 , respectively, within the receptacle housing  50  of the second connection part  5 . By the interaction of the detention cam  104  with the front side  43  of the insertion section  40 , the securing disk  10  is oriented by means of a pivot movement relative to the pivot bolt  51  such that the defining cam  102  strikes the pressure release stop  54 , wherein the force P presses the outer contour  106  against the recess surface  117  and the securing disk  10  is thus fixed so as to engage with the peripheral groove  42  in a wedged manner. 
     When pressure is applied to the first hose line  2  or a non-illustrated second hose line, the first connection part  4  is pressed out of the receptacle housing  50  linearly by means of the excess pressure. 
     Due to the interaction of the detention cam  104  with the front side  43 , the securing disk  10  is pivoted minimally in counter-clockwise direction and is pressed linearly against the recess surface  117  by means of the force P. 
     Tests have shown that a pressure release or ventilation does not necessarily take place in response to the transition into the pressure release position, because the flexible sealing ring  502  still remains in a sealing contact with the first connection part  4 . The sealing rings  502  are made from synthetic materials and are embodied in a flexible manner, wherein the sealing rings  502  must be resistant against chemicals, depending on the field of application of the lever arm coupling  1 , and must withstand the maximally occurring pressures. 
     To ensure a pressure release or ventilation of the lever arm coupling  1  in response to the transition into the secured pressure release position, at least one pressure release hole  56  and/or at least one pressure release pocket  57  can be optionally installed in the housing wall  501 , as is illustrated in  FIGS. 7   a  and  7   b.    
     The pressure release hole  56  can be arranged in the area of the sealing ring  502  so as to permeate the housing wall  501 . In the figures, an exemplary pressure release hole  56  is arranged so as to radially point to the ring-shaped housing wall  501 . A different orientation of the pressure release hole  56 , for example approximately parallel to the longitudinal axis of the receptacle housing  50 , is possible, wherein the sealing ring  502  closes the pressure release hole  56  so as to form a seal in response to the connection of the first connection part  4  to the second connection part  5 . 
     The pressure release pocket  57  can be introduced into the edge of the housing wall  501  in any orientation, wherein the sealing ring  502  allows for a liquid and gas-tight connection in response to the connection of the first connection part to the second connection part  4 ,  5 . The pressure release pocket  57  recessed in the housing wall  501  can be recessed directly in response to the production of the receptacle housing  50  or can be milled out, for example, in a retroactive processing of the receptacle housing  50  in the edge area of the interior of the receptacle housing  50 . 
     When the lever arm coupling  1  is brought into the secured pressure release position, the sealing ring  502  can be moved and can tilt in the direction of the first connection part  4 , wherein liquid or gas can escape from the first hose line  2  after passing through the pressure release hole  56  and/or the milled pressure release pocket  57 . In the case of the pressure release hole  56 , gas or liquid can escape from the pressure release hole out of the receptacle housing  50  towards the outside, whereby the pressure release or ventilation is guaranteed. In the case of the pressure release pocket  57 , which is milled into the housing wall  501 , gas or liquid can escape out of the second connection part  5  at the housing wall  501  within the receptacle housing  50  past the first connection part  4 . 
     Test series have shown that the recess  115  is to preferably encompass a recess surface  117 , which runs beveled relative to the elongated hole  101 . The recess surface  117  should not be oriented parallel to the longitudinal axis C-C suggested in  FIG. 6   a . An advantageous jamming of the securing disk  10  can thus be reached in the recess  115  and the outer contour  106  can still move across the recess surface  117  and a release of the securing disk  10  is possible as soon as the flat area  107  is guided past the recess surface  117 . 
     A further embodiment of a securing disk  10 ′, which prevents a sudden movement of the lever arm from the locking position to the release position in response to an excess pressure in the first hose line  2 , is illustrated in  FIG. 8 . 
     In addition to the features described above, the securing disk  10 ′ encompasses a plane surface  109  and a projection  108 , which abuts on the outer contour  106  and the plane surface  109 . The recess surface  117  of the recess  115  of the lever arm  11  moves across the outer contour  106  of the securing disk  10 ′, as was already explained above. After the release position of the lever arm  11 , the edge of the recess surface  117  touches the projection  108 , whereby the movement across the plane surface  109  and thus the outer contour  106  is slowed down. An unintentional and sudden opening of the lever arm coupling is thus made impossible, because the force P presses the securing disk  10 ′ and thus the plane surface  109  and the abutting projection  108  against the recess surface  117  of the lever arm and thus wedges it in response to a pressurized lever arm coupling. After an automatic or manual pressure release has been carried out, the movement of the lever arm  11  comprising the securing disk  10 ′ can take place into the decoupling position. 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               1  lever arm coupling 
               2  first hose part 
               4  first connection part 
               40  insertion section (tapered) 
               41  rear side 
               42  peripheral groove (ring-shaped) 
               43  front side 
               5  second connection part 
               50  receptacle housing 
               500  receptacle space 
               501  housing wall (ring-shaped) 
               502  sealing ring 
               51  pivot bolt 
               52  radial opening 
               53  release stop 
               54  pressure release stop 
               55  locking stop 
               56  pressure release hole 
               57  pressure release pocket 
               10  securing disk 
               101  elongated hole 
               102  defining cam 
               103  release surface 
               104  detention cam 
               105  carry-along cam 
               106  outer contour 
               107  flat area 
               108  projection 
               109  plane surface 
               11  lever arm 
               111  cylindrical hole 
               112  pressure application section 
               114  pressure surface 
               115  recess 
               116  release point 
               117  recess surface 
             A second direction/counter-clockwise direction 
             B first direction/clockwise direction 
             P force
A lever arm coupling for detachably connecting hose lines has a first connection part and a second connection part, the coupling operable by way of at least one lever arm. The lever arm comprises a pressure application section that is mounted pivotably about a pivot bolt that defines a pivot axis, the pressure application section reaching through a radial opening into a receptacle space of a receptacle housing. A securing disk is pivotably disposed on the pivot bolt parallel to the pressure application section. The securing disk is mounted pivotably between stops at the second connection part and can be carried along with the lever arm, wherein a pivoting of the securing disk can be executed in such a way that a secured pressure release position of the lever arm coupling is attained.