Abstract:
A switching device including a movable contact member. The movable contact member produces an isolating distance and includes an integral semiconductor switching element.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a switching device having a movable contact member for producing an isolating distance, and having a switching element integrated in the contact member. 
     BACKGROUND INFORMATION 
     Switching devices having a movable contact member for producing an isolating distance, and having a switching element integrated in the contact member are known as fuse disconnecting switches. In these devices, the movable contact members contain fuses whose ends are provided with blade contacts, as is described in, for example, German Utility Model G 94 04 155.5. 
     It is also conventional for a load-current switch or circuit-breaker to be connected toward the input side in series with a switching unit, for example a soft starter for three-phase asynchronous motors. 
     For electronic branch switches, the use of semiconductor switching elements which, for example, contain silicon or, in a particularly advantageous way, silicon carbide as substrate is recommended. Despite the outstanding insulating properties of silicon carbide given appropriate driving into the locking state, a visible isolating distance is to be ensured for safety reasons in the case of interruption of the current flow. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to improve a switching device of the above-named type so that the advantageous properties of semiconductor switching elements are associated in a simple way with the requirement for a visible isolating distance. 
     The object is achieved according to the present invention by virtue of the fact that the switching element is a semiconductor switching element. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a switching device having semiconductor switching elements integrated in a movable contact member, in the closed state, 
     FIG. 2 shows a switching device having semiconductor switching elements integrated in a movable contact member, in the open state, and 
     FIG. 3 shows a switching device having semiconductor switching elements and, in series therewith, a switch which can be remotely actuated and has an interrupting element. 
    
    
     DETAILED DESCRIPTION 
     In accordance with FIG. 1, the switching device according to the present invention includes at least one semiconductor switching element  1  which is integrated into a movable contact member  2  serving to produce an isolating distance. In the case of the switching device in accordance with FIG. 1, two bidirectionally connected semiconductor switching elements  1 , whose substrate consists, for example, of silicon or silicon carbide, are a component of the movable contact member  2 . In this arrangement, the connections of the movable contact member  2  are advantageously constructed as blade contacts, as is known from fuse disconnecting switches. In this case, FIG. 1 shows the closed state of the switching device, whereas in FIG. 2 its open state is represented, in which an isolating distance  4  is visible after opening of the movable contact member  2 . The switching device can be of single-phase and/or multi-phase design. 
     A further embodiment of the switching device according to the present invention is represented in FIG. 3, and in this case the semiconductor switching elements  1  are arranged in a fixed fashion, and connected in series therewith is an isolator or switch  3  which can be remotely actuated and by means of which the requirement for a visible isolating distance can be fulfilled. 
     Remotely actuated switches and semiconductor switches can form a hardware unit in this case. The semiconductor switching elements can also be remotely actuated, for example by a motor. 
     In the case of the multi-phase design of the switching device having a semiconductor switching element  1  integrated in the contact member  2 , it disadvantageous to provide a common drive for the circuit.