ALEXANDRIA, Va., June 6 -- United States Patent no. 12,281,532, issued on April 22.
"Predetermined load release device for a jar" was invented by Robert W. Evans (Montgomery, Texas).
According to the abstract* released by the U.S. Patent & Trademark Office: "A release device for a jarring tool includes a collet positioned between the mandrel of the jarring tool and a trigger sleeve. At least one end of the collet is in contact with a precompressed spring via a bushing. In order for the jarring tool to operate, a force greater than the precompressed force of the spring must be applied to the mandrel so that the collet can move in axial direction against the spring thereby releasing the mandrel."
The patent was filed on Oct. 31, 2023, unde...