ALEXANDRIA, Va., Nov. 6 -- United States Patent no. 12,460,385, issued on Nov. 4, was assigned to Hitachi Construction Machinery Co. Ltd. (Tokyo).
"Power transmission device for vehicle" was invented by Makoto Nakagaki (Tsuchiura, Japan) and Takuma Koinuma (Tsuchiura, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A first variable relief valve (51A) allows the flow of a hydraulic oil from a first main line (37A) to a second main line (37B) to be in a blocking state in a case the pressure of the first main line (37A) is a first pressure or less and to be in a communicating state in a case the pressure of the first main line (37A) exceeds the first pressure. A second variable relief valve (51B) allows th...