The invention relates to an interlocking system for the drive of a medium voltage switchgear, according to the preamble of claim 1 .

State of the art

In the state of the art, it is known to have one or two preselecting levers for opening the actuation of a so called two-position- or three-position-switch.

The main function is, that the actuation openings are accessible in the right positions only. Another function of the interlocking's in a two-position- or three- position-switch is, that a flap, which opens the operation openings for a lever can be closed in end positions only.

To operate a two-position- or three-position-switch manually, end blocks are necessary to define the correct positions. For this functions separate solutions with standard mechanic elements are available. In it's combination the two- position- or three-position-switch can be equipped with the necessary features.

The problem is, the existing solutions are a combination of several mechanical elements, which are connected with lever bolts etc. Object of the invention

It is an object of the invention, to ensure, that final end positions are reached surely, before other positions can be initiated, and that this will be realized by a compact construction.

Description of the invention

The invention consists of an operation mechanism which combines the function of the flap interlocking's and the end block for manual operation of a three- position-switch.

So the characterizing features of claim 1 are, that operation mechanism for the switching in normal operation case, that means except of an emergency operation, is directly coupled to the opening or shuting function of a flap on an operation opening for the manual lever drive in such, that the concerning opening for a further switching operation is given free only after reaching a switching end position.

An advantageous embodiment is, that flap interlockings are coupled with an end block for manual operation of a three-position-switch.

Furthermore advantageous and more detailed function is, that in case or a safe operation, if the motor stops in an intermediate position due to leak of secondary voltage or another failure, an emergency operation is given by delockinq means for the flap, such, that the flap can be opened but not closed again, before the drive has been moved in one of the defined end positions.

Constructurally advantageous is, that that the interlocking means combines three functions in one component, in such, that the access to the manual operation shafts is only free in its end positions and/or if the system stops in intermediate position.

So, the mechanic block of the interlocking is integrated and the flap can be closed in in reached end position only.

A further advantageous embodiment is, that the interlocking system is perfomed as an one-part-construction only for a two-position- or three-position-switch.

A further advantageous embodiment is, that in case of the use of the

interlocking system in motor driven mode, the driving element is not blocked and can move in all directions, the system is initiated to stop, if an electronic control system recognize, that the requested position is reached.

An advantageous embodiment is, that in case of manual operation the driving element is automatically blocked in movement in one direction and in the second direction it is free, and the system is blocked mechanically by the aforesaid blocking elements in end the positions.

Referring to that, if the switch is in middle position, the switch can be operated with both levers to one or the other direction, disconnector or earther.

In a further advantageous embodiment it is said, that if the switch is driven by motor drive mode, it stops in intermediate position, an interlocking element is provided, to realize that the actuation lever can be plugged in and the drive can be driven manually in its defined end position.

In an advantageous embodiment, the interlocking element is realized as a hinge solution, interacting with a movable nut, corresponding to the driven element.

An embodiment of the invention is shown in the figures 1 to 5. Above mentioned functionality is shown in figure 1 .

So concluding that, an additionally feature to the invention is, like shown in figure 2, that if the motor stops in an intermediate position due to leak of secondary voltage or another failure, an emergency operation is given and the flap 1 can be opened but not closed again before the drive has been moved in one of the defined end positions.

As follows, a design and operating description is shown in figure 1 . The main element is interlocking 4.

The advantage of the new design, like shown in figure 1 is, that the interlocking 4combines three functions in one component. The access to the manual operation shafts is only free in its end positions and/or if the system stops in intermediate position. The mechanic block is integrated and the flap 1 can be closed in its end position only. These features are provided by one part only for a two-position- or three-position-switch.

In motor mode the driven element 5 is not blocked and can move in all directions. The system stops, if the electronic control system recognize, that the requested position is reached.

At manual operation the driven element 5 is automatically blocked in movement in one direction and in the second it is free. The system is blocked mechanically in end positions.

If the system is in middle position, the system can be operated with both levers to one or the other direction, disconnector or earther.

If the system driven by motor drive mode stops in intermediate position, the interlocking element 6 be realize in such, that the actuation lever can be plugged in and the drive can be driven manually in its defined end position. The beam of the interlocking element 6 don't allow to close the interlocking flap unless the system reach its end position.

The beam/interlocking element 6 can be realized for example as a hinge solution, like shown in figure 3, interacting with the movable nut 7, which corresponds to the driven element.

Figure 4 shows the interlocking 4 for the driven element 5, with its detailed structure and which is implemented into the drive system, shown in figure 5.

Figure 5 shows the driven element 5, with the interlocking, shown in figure 4, implemented into the drive system. A front plate of the switch is provided with two openings which are closed by the prediscribed flap, which is embellished as an in two directions pivotable double flap.

So the locking system, like already shown in figure 4, is implemented axially into the final driving axis of the drive system in figure 5.

The conditions for blocking are shown in the figures 1 to 3.

Like it can be seen, the implemented functionality results in a compact construction of the drive system, with the aforesaid functionality.

List of reference signs

1 flap

2 opening for manual drive shaft 3 opening for manual drive shaft

4 interlocking

5 driven element