ALEXANDRIA, Va., June 16 -- United States Patent no. 12,305,737, issued on May 20, was assigned to NSK LTD. (Tokyo).
"Ball screw" was invented by Takayuki Yabe (Kanagawa, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A nut of a ball screw is formed with, in a notch portion, an elongated hole that penetrates in a radial direction, and whose longitudinal direction is formed along a lead angle and parts of both longitudinal side surfaces parallel to each other guide balls. A circulation part includes: a first circulation component that is disposed in the notch portion so as to abut against a bottom wall surface of the notch portion and has a tongue portion accommodated in the elongated hole; a second cir...