Downshifting work vehicle using differential lock switch

摘要

The differential lock switch for a work vehicle is used to trigger a control system for downshifting the vehicle from second to first. The control system comprises five relays. The first three relays detect if the vehicle is in second; if the vehicle is going forward; and if the differential lock switch is actuated. The fourth relay is used to latch the signal from the third relay so that the differential lock switch can be released and the vehicle will remain in first. The fifth relay receives signals from the first four relays and manipulates the correct solenoid valves for downshifting the vehicle.