Drive unit for a wiper system of motor vehicles

A drive unit comprising:

• a crank arm formed of malleable material defining a through bore and generally parallel front and back surfaces;
• and
• an elongate element having an intermediate portion extending through said bore and
• said elongated element further having a radially extending arresting flange formed thereon, axially abutting said back surface;
• said elongate element also having a pair of ends each adjacent a respective one of said front and back surfaces of said crank arm, a ball shaped linking element formed on each end of said elongate element having a radially opening circumferential groove formed therein of a half circular cross sectional shape, said groove disposed within said bore and axially spaced from said front surface,
• said elongated element formed with first and second annular areas on either side of said circumferential groove, said annular areas each fit into said bore;
• and
• wherein crank arm material at said front surface of said crank arm is displaced so as to define an annular recess substantially concentric to said bore and radially spaced outwardly thereof, and material of said crank arm around said bore radially displaced to bulge radially into said half circle cross section of said circumferential groove, thereby forming a holding element axially affixing said crank arm to said elongate element.