ALEXANDRIA, Va., Oct. 21 -- United States Patent no. 12,766,584, issued on Oct. 20.
"Diameter-expanding tool head and diameter-expanding method thereof" was invented by Cheng-Chia Peng (Taichung City, Taiwan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A diameter-expanding tool head and a diameter-expanding method thereof, the tool head comprises an expanding section forming convex portions and concave portions disposed at intervals on an outer peripheral surface, any one of the concave portions is formed between any two of the convex portions, each of the convex portions has a convex peak, the convex peak is a part farthest from an axis, each distance is equal, the convex peaks are connected to form a dia...