FRONT WHEEL SPEED-INCREASING MECHANISM FOR FOUR-WHEEL-DRIVE TRACTOR

摘要

PURPOSE:To improve the response characteristic of switching a speed increase, by connecting a handle to a speed increase switching arm through a pitman arm, transmission link and a bell crank mechanism, in the case of a tractor increasing speed of the front wheel being associated with a steering handle. CONSTITUTION:When a steering handle 6 is controlled, a tractor, longitudinally turning a pitman arm 7 through a steering box 39 while turning a steering bell crank 8 through a drag rod 35, drives a front wheel to be steered. The tractor connects an adjusting link 40 to the pitman arm 7 further mounts a turnbuckle mechanism, which adjusts switching to speed increase driving and to normal driving in accordance with a steered angle of the handle 6, interposing in the adjusting link 40. A press moving link 42 is connected to the adjusting link 40 through a bell crank 41 as well as a speed increase switching arm. In this way, a front wheel speed increasing mechanism improves its response while enabling fine adjustment to be performed.