| 摘要 |
<p>1409485 Crop harvester DEERE & CO 23 March 1973 [23 March 1972] 14178/73 Heading A1F A crop harvester having a vertically movable crop-gathering unit and an automatic height control system has laterally spaced individual ground followers 50 electrically connected through a logical circuit to a solenoid valve 116 which has raise, hold, or lower modes for the supply of fluid to cylinders 26 to control the movement of the crop gathering unit. Ground followers 50 are welded to sleeves 58 having magnets 66 on pedestals 68 which can actuate reed switches 70 (70a-70e Fig. 6) according to whether the ground follower is in the upper, one of the intermediate or lower position. For transporting the machine, the operator closes the main switch 90 and selects switch 136 to connect lead 134 to lead 140 thus bringing limit switch 142 into circuit. With switch 90 closed current from battery 76 flows through the transistorised circuit to solenoid 112 which moves valve 116 to a raise mode. Cylinders 26 extend until the limit switch 142 is opened by the abutment member 184 which deactivates solenoid 112 so that valve 116 returns to a hold mode. With the crop gathering unit in the transport position ground followers 50 are in their lowermost position so that magnets 66 are below all the reed switches 70 and the latter are all open. For field operation of the machine switch 136 is moved to the Fig. 6 position. Current then flows through the transistorised circuit to solenoid 114 which moves valve 116 to a lower mode so that the crop gathering unit begins to lower. With the 2 pole height selector switch 8 set as in Fig. 6, when one of the ground followers 50 engages the ground and pivots upwards the respective reed switch 70a is activated by the magnet 66 and the solenoid 114 is deactivated and valve 116 returns to the hold mode. With the machine transversing a field and switch 78 set as in Fig. 6 of all the ground followers cause their respective magnets 66 to drop below the reed switches 70 a solenoid 114 is activated through the logical circuit and the crop gathering unit is lowered. If one or more of the ground followers closes its respective reed switch 70b solenoid 112 is activated through the logical circuit and the crop gathering unit rises. The working height can be varied by moving the 2 pole switch 78 to an alternative position.</p> |
