ALEXANDRIA, Va., March 24 -- United States Patent no. 12,584,378, issued on March 24, was assigned to EPIC LIFT SYSTEMS (Houston).
"Dart and clutch assembly" was invented by Robert G. Roycroft (Houston) and Shannon Freeman (Tomball, Texas).
According to the abstract* released by the U.S. Patent & Trademark Office: "Described herein are embodiments of systems and apparatuses that include a dart and/or a clutch for a dart plunger. In an exemplary embodiment, the dart plunger includes a dart adapted to move between a first position and a second position and also between a maximum closed position and a minimum closed position. Varying diameters of the dart enable the clutch to variably retard movement of the dart between its first, second, ma...