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:
Aug. 01, 2017
Filed:
Jun. 19, 2015
Black & Decker Inc., Newark, DE (US);
John C. Vanko, Timonium, MD (US);
Larrry T. Albert, Abingdon, MD (US);
Michael K. Forster, White Hall, MD (US);
Bhanuprasad V. Gorti, Perry Hall, MD (US);
Jason K. Leh, Rosedale, MD (US);
Garrett P. McCormick, Manchester, MD (US);
Samuel G. Woods, Bel Air, MD (US);
David R. Beers, Dallastown, PA (US);
Black & Decker Inc., New Britain, CT (US);
Abstract
A protective redundancy circuit is provided for a power tool having an electric motor. The protective redundant subsystem is comprised of: a motor switch coupled in series with the motor; a motor control module that controls the switching operation of the motor switch; and a protective control module that monitors switching operation of the motor switch and disables the power tool when the switching operation of the motor switch fails. In the context of an AC powered tool, the switching operation of the motor switch is correlated to and synchronized to the waveform of the AC input signal. During each cycle or half cycle, the motor control module introduces a delay period before closing the motor switch and the protective control module determines the operational status of the motor switch by measuring the voltage across the motor switch during the delay period.