Differential lock control system for agricultural vehicles

In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting rotary motion from the engine to the driven wheels and permitting relative velocity between the driven wheels, a differential locking mechanism engageable to limit the relative velocity between the driven wheels in response to control signals and a brake coupled to each driven wheel, a control system comprising:

• a brake detecting circuit coupled to the brakes and configured to generate a braking signal upon application of a brake;
• and
• a control circuit coupled to the brake detecting circuit and to the differential locking mechanism and configured to generate control signals and to apply the control signals to the differential locking mechanism to selectively engage, disengage and re-engage the mechanism in response to the braking signal.

In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting rotary motion from the engine to the driven wheels and permitting relative velocity between the driven wheels, a differential locking mechanism for limiting the relative velocity between the driven wheels in response to control signals and an implement positioning system for raising and lowering an implement coupled to the vehicle, a control system comprising:

• an implement position detecting circuit coupled to the implement positioning system and configured to generate an implement position signal representative of the implement position;
• and
• a control circuit coupled to the implement position detecting circuit and to the differential locking mechanism and configured to generate control signals and to apply the control signals to the differential locking mechanism to engage the differential locking mechanism when the implement is in a first position and to disengage the mechanism when the implement is in a second position.

In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting rotary motion from the engine to the driven wheels and permitting relative velocity between the driven wheels, a differential locking mechanism for limiting the relative velocity between the driven wheels in response to control signals, a control system comprising:

• a ground speed sensor configured to detect a parameter proportional to the ground speed of the vehicle and to generate speed signals representative thereof;
• and
• a control circuit coupled to the ground speed sensor and to the differential locking mechanism and configured to generate control signals and to apply the control signals to the differential locking mechanism to engage the differential locking mechanism when the vehicle ground speed falls below a predetermined speed, to disengage the mechanism when the vehicle ground speed exceeds the predetermined speed and to re-engage the mechanism when the vehicle ground speed again falls below the predetermined speed.