ALEXANDRIA, Va., June 19 -- United States Patent no. 12,330,915, issued on June 17, was assigned to INVENTIO AG (Hergiswil, Switzerland).
"Elevator system having a circuit with a switch monitored by means of an AC voltage signal" was invented by Astrid Sonnenmoser (Hochdorf, Switzerland), Ivo Lustenberger (Buttisholz, Switzerland), Kurt Heinz (Buchs, Switzerland) and Thomas Hartmann (Kleinwangen, Switzerland).
According to the abstract* released by the U.S. Patent & Trademark Office: "An elevator system controller controls a drive and optionally further elevator components. The controller includes a circuit having a switch to be monitored, the switch having an input and an output, a signal transmitter unit applying an AC voltage input sig...