connecting bolt nuts 11 on the connecting bolt threads 13 a of the corresponding connecting bolt shank 14 to a selected torque thus varying the clearance in the shoulder space 5 a as further illustrated in fig3 of the drawings the interior belleville springs 7 are fitted against each other in sets of two or more in selected assemblies at the respective cupped or concave faces to allow flexure and facilitate the desired spring tension in the segment connection the segment shoulder 5 on each of the drive segments 17 creates a stop surface for the lower spring washer 8 a that is seated against the connecting bolt head 13 in a spaced apart clearance from the bottom end of the segment base 18 of the adjacent drive segment 17 at the shoulder space 5 a the shoulder space 5 a allows variable tensioning of the belleville springs 7 by selectively tightening and loosening the connecting bolt nuts 11 to a desired torque and thus facilitates adjusting the degree of articulation or flexure of the drive segment receiving segment interconnection at the respective ends of the segment housings 2 accordingly referring again to fig1 and 3 of the drawings when a selected number of the segment housings 2 of the sectional drive and coupling system 1 are connected in a drive and coupling string 10 as illustrated in fig1 and 3 the entire sectional drive and coupling system 1 is able to flex and define a curvature such as that illustrated in fig1 because of the selected flexure provided in each of the joints.