Automatic winch level adjustment system on combine harvester - has IR transmitters and receivers at two levels providing signals from crop height

摘要

A winch has a mechanism for automatically adjusting the height in a combine harvester etc. It relieves driver of the harvesting machine from having to operate the winch when the crop is of uneven height. The winch is fitted with two infrared transmitters on one side. The receivers are fitted on the other side with microswitches. A pulse from the transmitters controls the corresponding microswitch. The pulse is produced by the infrared beam being interrupted by the height of the crop. It interrupts the power supply to the receiver concerned so that the microswitch in question switches the coil off. The spring-loaded bridging contact switches the hydraulic control instrument to stop and the winch remains in the same position.