Hilti Aktiengesellschaft

Lutz Troeder

Helmut Burger

Franz Hoyss

Peter Hellmann

Claus Osselmann

Georg Brami

Ernst-Rudolf L&uuml;bkert

A process and a circuit ( ) for regulating the speed of an electric motor ( ) having a high speed (N ) to at least one additional lower speed (N , N , N ), whereby, in a first prioritized step, depending on a preselected speed (N , N ), the regulation of the speed to a lower effective motor voltage (Ueff) has an upper limit, and in a second step, depending on the torque (M) needed for the regulation to this preselected speed (N , N ), the effective motor voltage (Ueff) is regulated within the limited range.

Circuit and process for regulating the speed of universal electric motors

The hand-held drilling and/or screwing implement has a housing with a handle, an electrical driving motor, a carbon brush holder ring and a switching body, which interacts rotationally locked with the carbon brush holder ring. At the carbon brush holder ring, two carbon brush holders are disposed opposite to one another and the switching body has an actuating element, which is disposed on the side opposite to the handle. With the help of an axial positive connection, the carbon brush holder ring can be fastened to the stator, so that it can be inserted together with the stator as a unit in the housing.

Drilling implement

In a stator for an electromotor, field coils associated with a packet of laminations are spaced apart by filler pieces. The combination of the field coils and filler pieces form an annular arrangement. Each filler piece extends between the adjacent ends of two field coils. The filler pieces are slotted in the radial direction to provide a certain adjustability in the circumferential direction of the annular arrangement where the dimension between the adjacent ends of the field coils is subject to variation.

Growing community of inventors

Türkenfeld, Germany

Lutz Troeder