Abstract: A shifting mechanism for the hydrostatic transmission of an earth moving machine comprising a shift lever manually operable by the machine operator to effect the speed and direction of movement of the vehicle. The shift lever is coupled to a hydraulically-actuated friction stop mechanism for maintaining the shift lever in a predetermined position by means of a fluid coupling which may be readily disconnected by the vehicle operator to adjust the positioning of the shift lever free from any frictional forces holding the shift lever in the prior position. A release system is provided wherein upon application of the vehicle brakes, the frictional force holding the shift lever in the predetermined position is released and the shift lever automatically returned to a neutral or idle position thereby disengaging the vehicle transmission.

Abstract: An hydraulic steering device for a crawler-mounted vehicle, in which a couple of pressure-regulating steering valves controls the rotation direction and speed of two respective rolling trains of the vehicle, is described. Each of the valves is provided with an end chamber having a piston sliding therein in response to a control pressure depending on the pilot pressure regulated by the other steering valve, and each piston is designed to shift respective shouldering means for respective contrast springs of respective shuttles provided on the valves in such a manner that both the rolling trains are stopped whenever both of the valves are activated simultaneously.