The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 22, 2014
Filed:
Oct. 31, 2008
Ulrich Single, Penang, MY;
Michael Habele, Waldenbuch, DE;
Ulrich Single, Penang, MY;
Michael Habele, Waldenbuch, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
The invention relates to a device () for taking a safety precaution in an electrical tool, said electrical tool comprising an electric motor (EM) with at least one field winding and an armature winding. The device () comprises the following features: a sensor unit () which is designed to generate a sensor signal () in accordance with a motor current () passing through the electric motor (EM), an armature voltage () via the armature winding, a voltage () via the field winding and/or a commutation frequency () in the armature winding; a unit () detecting a change of the sensor signal, which is designed to detect a temporal change of the sensor signal () and emit a corresponding modification signal () on the basis of the detected change; and a safety device () which is designed to take a safety precaution () in the electrical tool when a value of the modification signal () is exceeded or not met in relation to a threshold value.