ALEXANDRIA, Va., Sept. 10 -- United States Patent no. 12,411,155, issued on Sept. 9, was assigned to YOKOWO Co. LTD. (Tokyo).
"Plunger and contact probe" was invented by Kenichi Sato (Tomioka, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A plunger includes a conductive base layer, and a platinum group layer which is provided on the outside of the base layer and which contains a platinum group element as a main component. The plunger has the base layer as its base material, and has the platinum group layer on the outside of the base layer at the tip part to come into contact with an inspection object. A contact probe includes the plunger, and a spring which abuts on the plunger at an end part."
The p...