Tricycle with driven rear wheel - has steerable front wheels on parallelogram linkages permitting steering and inclination from vertical

摘要

The triangle has two front wheels (13) with narrow track width carried on steering arms (12), as well as a driven rear wheel. The upper and lower ends of the arms are coupled by ball-joints (10, 11) to transverse rods (8, 9) whose centres are pivoted (6, 7) to the main frame (1) and to a central rod (3) parallel to the arms respectively, to form a double parallelogram linkage. The pivots only allow rotation about axes parallel to the longitudinal tricycle axis (x-x), whilst the four ball joints allow rotation about axes parallel to this axis and about the arm centre lines to permit steering motion.