Abstract:
A drive for a switching device having a contact system with a fixed contact and a moving contact, includes a force initiation element for initiating a drive force, an actuator for actuating the moving contact to close or open the contact system and a transmission disposed between the force initiation element and the actuator. The transmission allows both transferring the contact system from the closed to the open state and transferring the contact system from the open to the closed state to be triggered by a drive force in the same direction, making the drive cost-effective and compact.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a drive for a switching device, which has a contact system made up of a fixed contact and a moving contact, having a force initiation element for initiating a drive force and an actuator for actuating the moving contact to close or open the contact system as well as transmission means disposed between the force initiation element and the actuator. 
     Such a drive is known from the generally accepted prior art and has as its force initiation element for example a spring storage system and as its actuator a drive rod coupled to the moving contact, a mechanical rocker system with a rotatably supported rocker being provided as the transmission means, the rocker transmitting the drive force of the force initiation element to the drive rod to open or close the contact system of the switching device. 
     BRIEF SUMMARY OF THE INVENTION 
     It is the object of the present invention to develop a drive of the type mentioned in the introduction, which is economical and compact in structure. 
     According to the invention this is achieved with a drive of the type mentioned in the introduction in that the transmission means are configured in such a manner that both the transferring of the contact system from the closed to the open state and the transferring of the contact system from the open to the closed state can be triggered by a drive force in the same direction. 
     Such a drive is both economical and compact because with transmission means configured in this manner, with which the transferring of the compact system from the closed state to the open state and the transferring of the contact system from the open to the closed state can be triggered by a drive force in the same direction, complex mechanisms for reversing movement can simply be avoided. 
     In one advantageous embodiment of the invention the transmission means have a rotatable rod which has a staged profile on its end facing the actuator for transmitting force to the actuator. Such a staged profile on a rotatable rod for transmitting force to the actuator to actuate the moving contact of the switching device is particularly advantageous because by initiating the drive force of the force initiation element and executing a rotation of the rotatable rod, the actuator can be transferred both by the staged profile from a lower first level of the staged profile with the contact system of the switching device open along an incline by way of a latching stage to an upper second level of the staged profile with the contact system of the switching device closed, and can also be transferred from the upper second level and closed contact system by way of a latching stage to the lower first level of the staged profile to open the contact system with the initiated drive force in the same direction. 
     The force initiation element here can be configured in different ways. It is particularly preferable for a solenoid drive coupled to a deactivation spring to be provided as the force initiation element, said solenoid drive being provided to initiate a drive force in the transmission means in just one direction, with the force of the solenoid drive bringing about the transferring of the staged profile of the rotatable rod from its lower to its upper level to activate or close the contact system of the switching device and during deactivation the force in the same direction of the solenoid drive causing the staged profile to be transferred from the upper to the lower level in conjunction with the deactivation spring. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAAL VIEWS OF THE DRAWING 
       The invention is described in more detail below based on the drawing and an exemplary embodiment with reference to the accompanying figures, in which: 
         FIG. 1  shows an exemplary embodiment of an inventive drive with a switching device in a first position; 
         FIG. 2  shows the exemplary embodiment of the inventive drive from  FIG. 1  with a switching device in a second position; 
         FIG. 3  shows an exemplary embodiment of a staged profile; and 
         FIG. 4  shows a further exemplary embodiment of a staged profile of the inventive drive. 
     
    
    
     DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a drive  1  for a switching device  2 , for example in the form of a vacuum switching tube, having a contact system  3  made up of a fixed contact  4  and a moving contact  5 . The fixed contact  4  is connected in an electrically conducting manner by way of a fixed contact connector pin  6  to a first connector  7  of the switching device  2 , the moving contact  5  is connected in an electrically conducting manner by way of a moving contact connector pin  8  to a second connector  9  of the switching device  2 , with an electrically conducting flexible segment  10  being provided between the moving contact connector pin  8  and the second connector  9 , so that movement of the moving contact connector pin  8  is permitted while maintaining the electrical connection to the second connector  9 .  FIG. 1  shows the contact system  3  in its opened state, in other words there is no conducting connection between the fixed contact  4  and the moving contact  5 . 
     The drive  1  comprises a force initiation element  11  and an actuator  12 , as well as transmission means  13  disposed therebetween. The force initiation element  11  serves to initiate a drive force to close or open the contact system  3  of the switching device  2  and in the exemplary embodiment has an electromagnet  14  with a coil  15 , said coil  15  being connected by way of connectors  16  and  17  to a voltage source (not shown in the figure) to energize the coil  15 . An armature  18  of the electromagnet  14  here is configured in such a manner that when the coil  15  is energized, the armature  18  is subject to a drive force upward in the direction of the arrow in  FIG. 1 . The force induction element  11  also comprises a deactivation spring  19 , which is fastened to a first bearing  20 , for example a housing segment of the switching device  2 , and is fastened at its second end to a counter bearing  21  fastened to the armature  18 , the deactivation spring  19  being shown in its relaxed state in  FIG. 1 . The transmission means  13  comprise a rod  22 , which is supported in such a manner that it can be rotated in relation to the armature  18 , said rod  22  having a staged profile  23  on its end facing the actuator  12 , which is described in more detail with reference to  FIGS. 3 and 4 . 
     The actuator  12  comprises an actuation rod  24 , which is configured by the staged profile  23  of the rotatably supported rod  22 , also a contact pressure spring  25  for applying a contact pressure force when the contact system  3  of the switching device  2  is in the closed state, as well as an isolating segment  26  for the electrical isolation of drive  1  in relation to switching device  2  and a coupling segment  27  for the mechanical coupling of the actuator  12  to the moving contact connector pin  8 . 
     To transfer the contact system  3  of the switching device  2  from the opened state illustrated in  FIG. 1 , a drive force is now initiated by the force initiation element  11 , in that the energization of the coil  15  and the generation of a corresponding magnetic field cause the armature  18  of the electromagnet  14  to be subject to a force upward in the direction of the arrow, as a result of which the rotatably supported rod  22  is caused to rotate in the direction of the rotary arrow, with the staged profile  23  of the rotatably supported rod  22  transferring the actuation rod  24  from the lower level  28  to the upper level  29 , thereby tensioning the contact pressure spring  25  and causing the moving contact connector pin  8  to be subject to an upward movement in the exemplary embodiment, so that the contact system  3  made up of the fixed contact  4  and moving contact  5  is transferred to the closed state, as illustrated in  FIG. 2 , in which the actuation rod  24  is in the upper level  29  of the staged profile  23  of the rotatably supported rod  22  and the contact pressure spring  25  is tensioned. The deactivation spring  19  is tensioned at the same time in this process. 
     To reverse this process, starting from the state in  FIG. 2  the coil  15  is once again energized to initiate a force in the armature  18  of the electromagnet  14  upward in the direction of the arrow, so that rotation of the rotatable rod  22  in the direction of the rotary arrow lifts the actuation rod  24  from the latch in the upper level  29  and further rotation of the rotatable rod  22  causes it to move back into the lower level  28  of the staged profile  23 , the energy from the deactivation spring  19  that is tensioned in  FIG. 2  being expended, causing the opening of the contact system  3  made up of the moving contact  5  and fixed contact  4  of the switching device  2 . 
     In other words it is possible with the drive  1  to trigger both the transferring of the contact system  3  from the open to the closed state and also the transferring of the contact system  3  from the closed to the open state by a drive force of the electromagnet  14  that is always in the same direction, in the exemplary embodiment upward. 
       FIG. 3  shows a detailed diagram of the staged profile  23  of the rotatable rod  22  from  FIGS. 1 and 2  as an opened out lateral surface of the rotatable rod  22  with the lower level  28  and the upper level  29 , the transition between lower and upper level being configured as an incline, as well as latching stages  30  and  31  that can be identified in  FIG. 3  and allow the latching of the switching device  2  when the contact system  3  is in the closed state. 
       FIG. 4  shows a further opened out lateral surface of the rotatable rod  22  in a further exemplary embodiment, with an intermediate level  32  being provided in addition to the lower level  28  and the upper level  29 , both the intermediate level  32  and the upper level  29  having corresponding latching stages and the transitions being embodied as inclines, so that a three position switch can be also be realized with the staged profile in  FIG. 4 , for example to realize the functions of closed contact system, opened contact system and isolating position with a large gap between fixed contact and moving contact of the switching device. 
     LIST OF REFERENCE CHARACTERS 
     
         
           1  Drive 
           2  Switching device 
           3  Contact system 
           4  Fixed contact 
           5  Moving contact 
           6  Fixed contact connector pin 
           7  First connector 
           8  Moving contact connector pin 
           9  Second connector 
           10  Flexible segment 
           11  Force initiation element 
           12  Actuator 
           13  Transmission means 
           14  Electromagnet 
           15  Coil 
           16 ,  17  Connectors 
           18  Armature 
           19  Deactivation spring 
           20  First bearing 
           21  Counter bearing 
           22  Rotatably supported rod 
           23  Staged profile 
           24  Actuation rod 
           25  Contact pressure spring 
           26  Isolating segment 
           27  Coupling segment 
           28  Lower level 
           29  Upper level 
           30  Latching stage 
           31  Latching stage 
           32  Intermediate level