Abstract: The purpose of the invention is to enable a crawler tractor to brake and stop certainly without applying a load to an engine and a driving mechanism, and without complicated operation. An operation link links a conic linkage (53) which links a steering wheel (7) with a main speed change lever (55) of the crawler tractor, and with an operation mechanism of a brake pedal (54). A neutral return mechanism for the operation link is provided. The operation link neutral return mechanism comprises a hook-like cam lever (61). When the brake pedal is depressed, the main speed change lever is moved to its neutral position before braking force occurs, and then, the brake is actuated. Accordingly, engine brake is used effectively, and the brake can be miniaturized.

Abstract: A tractor having right and left traveling crawlers (9) installed thereon, comprising a hydraulic transmission swing mechanism (45), a forced-diff (41) for driving a crawler driving sprocket (4), and an engine (10), a hydraulic transmission straight-ahead driving mechanism (25), and a transmission case (12) disposed from the front side to the rear side of a machine body in that order, wherein an allowance for heat radiation is provided to a space under a machine floor for storing the hydraulic transmission straight-ahead driving mechanism (25) to eliminate the problem of the machine floor becoming too high, and the forced-diff (41) is driven by the hydraulic transmission swing mechanism (45) with a simple structure.

Abstract: The purpose of the invention is to enable a crawler tractor to brake and stop certainly without applying a load to an engine and a driving mechanism, and without complicated operation. An operation link links a conic linkage (53) which links a steering wheel (7) with a main speed change lever (55) of the crawler tractor, and with an operation mechanism of a brake pedal (54). A neutral return mechanism for the operation link is provided. The operation link neutral return mechanism comprises a hook-like cam lever (61). When the brake pedal is depressed, the main speed change lever is moved to its neutral position before braking force occurs, and then, the brake is actuated. Accordingly, engine brake is used effectively, and the brake can be miniaturized.

Abstract: A tractor having right and left traveling crawlers (9) installed thereon, comprising a hydraulic transmission swing mechanism (45), a forced-diff (41) for driving a crawler driving sprocket (4), and an engine (10), a hydraulic transmission straight-ahead driving mechanism (25), and a transmission case (12) disposed from the front side to the rear side of a machine body in that order, wherein an allowance for heat radiation is provided to a space under a machine floor for storing the hydraulic transmission straight-ahead driving mechanism (25) to eliminate the problem of the machine floor becoming too high, and the forced-diff (41) is driven by the hydraulic transmission swing mechanism (45) with a simple structure.