GB607293A - Improved device for coupling together tractors and trailers - Google Patents

Abstract

607,293. Articulated vehicles; couplings. BLANCHARD, P. F. E. July 10, 1945, No. 17571. [Classes 79 (iii) and 79 (v)] A coupling device for a tractor and trailer comprises a system of two crossed bars pivotally secured to the frames of the tractor and trailer by cardan joints so that when turning, the fixed front axle of the towed vehicle automatically follows the turn and the extension of its axis meets the extension of the rear axle at the turning centre, the trailer rear wheels being steered positively by the connecting cross-bars. Fig. 1 shows a tractor 1 with a front axle 2 steered in a known manner and a fixed rear axle 7. Coupled to the tractor is a trailer 3 with a fixed front axle 6 and steerable rear wheels. Coupling is effected by means of two crossed bars 4 and 5, Fig. 2, the extremities a, b, c and d of which have cardan joints. In rounding a bend the front axle 6 of the trailer steers automatically by virtue of the relative movement of the two vehicles, whereas the steerable rear wheels mounted on king pins 9 and 10 and joined by track rod 11 are steered positively by a rod 12 whose one end is coupled to a steering arm 13 for the rear wheels and whose other end is coupled to another steering arm 14 rigid with the bar 4 at d. The rod 12 may be duplicated on the other side. The ends a, b, c and d are secured in cardon joints 22, 23 Fig. 3, secured respectively to gussets 18 and 19 which are in turn fixed on a horizontal bar 17 attached to the tractor or trailer.