| 摘要 |
A tractor drawn implement having a blade engageable with the ground and adjustable as to its depth of engagement whereby depth is increased over high spots and depth is decreased over low spots to transfer soil from high spots to low spots as the implement traverses the ground. A gauge frame trails a main frame carrying the blade and is coupled to a gauge beam whose elevation with respect to the main frame is altered as a function of the elevation of the gauge frame relative to the main frame and/or blade. The gauge beam is coupled to the gauge frame so that the articulation between the gauge frame and main frame provided for convenience in manipulating the implement and the freedom of transverse motion between frames is enabled without displacing the gauge beam from an operative relationship with control elements adjustably mounted on the main frame. Electro-hydraulic controls are illustrated. Solenoid operated hydraulic valves control the admission of fluid to a drive cylinder for pivoting ground engaging wheels on the main frame to raise and lower the frame and blade relativeto the underlying ground surface. Gauge beam supported limit switches control the valve solenoids and are actuated by cams supported on the main frame. A movable base for the cams has a motor driven positioner to raise or lower it and change the operative positions for the switches. The cams can be moved relative to the base for further adjustment of the actuating positions and dead zone range of relative motion.
|
