ALEXANDRIA, Va., Sept. 15 -- United States Patent no. 12,735,962, issued on Sept. 15, 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: "Systems and apparatuses that include a dart and/or a clutch for a dart plunger. In an exemplary embodiment, the clutch consists of a one-piece unit having a length, an outside diameter, and an inside diameter where at least a portion of the inside diameter is sized to create a frictional interface with a dart. The clutch may also include a gap, a slot, and/or a spiral cut. The dart may include a shaft having opposite ends and a...