ALEXANDRIA, Va., Sept. 23 -- United States Patent no. 12,421,959, issued on Sept. 23.
"Pad plunger" was invented by James Allen Jefferies (Granbury, Texas).
According to the abstract* released by the U.S. Patent & Trademark Office: "A pad plunger for lifting fluids in a well with a central mandrel attached to a top cap, a bottom cap, at least one capture ring, at least one canted coil spring, and at least one set of pads. The central mandrel is also comprised of at least one set of spring grooves, at least one pad groove disposed between the spring grooves, a central support ring, at least one outer support ring on the end of the central mandrel, and at least one series of outer threads beyond the outer support ring."
The patent was file...