Marquardt Gmbh

Jens Mueller

Alois Schaeffeler

August Geiger

An electric switch (1), in particular for electric hand tools having an electric motor operated by means of direct current. The switch (1) possesses a contact system (9) consisting of a fixed contact (10) and of a switching contact (11), an actuating member (3) for triggering a switching operation between an 'off' and an 'on' position of the contact system (9) acting on the switching contact (11). The contact system (9) is assigned means (18), consisting of a shield (19), for extinguishing an arc generated between the fixed contact (10) and the switching contact (11) during the switching operation. The shield (19) can be moved together with the switching contact (11) in a coupled manner, during the operation to switch the switching contact (11) from the 'on' to the 'off' position the shield (19) being moved into the region located between the fixed and switching contacts (10, 11). Conversely, during the operation to switch the switching contact (11) from the 'off' to the 'on' position, the shield (19) is moved out of the region located between the fixed and switching contacts (10, 11), so that the switching contact (11) can be laid onto the fixed contact (10).

Electric switch

The invention relates to an electric switch (1), especially for use for an electric hand tool having an electric motor, such as a battery-operated electric tool having a direct-current motor. The switch (1) possesses a housing (2) for receiving a contact system, a movable actuating member which acts on at least one switch contact of the contact system, and control electronics (26) located in the housing (2) as well as an associated power semiconductor (28) for varying the rotational speed of the electric motor. The power semiconductor (28) is connected via a current-bearing and heat-conducting carrier part (31) to the contact system located in the housing (2) and, further, is heat-conductively connected to a cooling body (34) located on the outside of the housing (2). The carrier part (31) extends through a wall perforation (33) of the housing (2) at least as far as the cooling body (34). To simplify assembly, the cooling body (34) is held directly on the carrier part (31) non-positively and/or positively without additional fastening means.

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Tuttlingen, Germany

Jens Mueller