ALEXANDRIA, Va., Sept. 10 -- United States Patent no. 12,408,586, issued on Sept. 9, was assigned to MAKITA Corp. (Anjo, Japan).
"Electric work machine" was invented by Masayuki Okamura (Anjo, Japan) and Kazuya Okuma (Anjo, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "An electric work machine includes a first and second motors; a first and second switches disposed on corresponding current conduction path from a direct-current power source to each motor; a first and second carrier frequency setting devices; and a controller. The first and second carrier frequency setting devices respectively set a first and second carrier frequencies of a time when PWM controlling an electric power supply to the first...