Robert Boschgmbh

Claude Wessel

Hans Gerber

Ivan Hidveghy

Eberhard Vogel

Marian St/u/ Rmer

G/u/ Nter Schaal

A portable electric device in which a surveying arrangement is incorporated for permitting a reading of the corresponding operating condition. The surveying arrangement consists of a visual reading instrument which is arranged on the casing so as to be within the range of vision and which is indicating respective characteristic data of the corresponding operating condition.

Indicating arrangement for portable electric devices

Speed regulation, either closed loop or open loop, in a hand-held electric tool such as a drill, a miller, a saw or, in particular, combination tools for home use, is carried out by use of a microcomputer. Then-present operating conditions such as the speed of the drill bit, the direction of rotation of the bit, the presently engaged gear, etc. are indicated by a display which has a plurality of fields which are selectively lit. Alternatively, the display can include a seven-segment indicator for displaying the speed. Overload indication is also furnished, as is an automatic shutoff when the motor current exceeds its nominal value. The display, overload indication and shutoff, etc. are all computer-controlled.

Growing community of inventors

Brugg, Switzerland

Claude Wessel