ALEXANDRIA, Va., Oct. 6 -- United States Patent no. 12,751,538, issued on Oct. 6, was assigned to Hilti AG (Schaan, Liechtenstein).
"Backpack device" was invented by Andreas Janecke (Landsberg am Lech, Germany) and Johannes Hammers (Vaduz, Liechtenstein).
According to the abstract* released by the U.S. Patent & Trademark Office: "A backpack device having a harness unit and a battery pack receptacle, fastened thereto, for receiving a battery pack for supplying a hand-held electrical device with energy, wherein the harness unit has a strap adjusting device via which a shoulder strap of the harness unit can be adjusted such that the battery pack receptacle can be moved from a back position into a waist position, wherein the shoulder strap re...