Linear interlocking key or spline

Claim 1

A LINEAR KEY OR SPLINE, AT LEAST TWO PARTS OR MEMBERS SPANNING RADIALLY ADJOINING SEGMENTS OF SAID KEY, TENONS AND MORTISES AND FLANKS COMMON THERETO EXTENDING LENGTHWISE ON SAID KEY, SAID FLANKS HAVING DIRECTIONS IMPARTING A REENTRANT SHAPE TO SAID TENONS AT AND NEXT TO THE KEY PERIPHERY, SAID MORTISES HAVING A MAXIMAL DEPTH SUBSTANTIALLY ONE HALF OF THEIR MAXIMAL WIDTH BETWEEN SAID FLANKS, SAID KEY HAVING A CONSTANT CROSS-SECTION AND SAID MORTISE DEPTH-TO-WIDTH RELATIONSHIP THROUGH THE EFFECTIVE LENGTH THEREOF, EACH OF SAID PARTS BEING IN A LENGTHWISE SLIDABLE CONTACT WITH SAID FLANKS ASTRIDE AT LEAST ONE TENON AND BEING CENTERED AND ANGULARLY ENGAGED THEREAT FOR SUBJECTING SAID KEY TO FORCES AT AND NEXT TO THE PERIPHERY THEREOF, AND BEING OUT OF CONTACT AT SAID MORTISES.