Abstract: An improvement in furrow followers of a type adapted for connection to an automatic steering mechanism for causing a vehicle to selectively follow a furrow is disclosed. The improvement provides a first and a second probe unit which are adapted to lie in a field furrow. The first probe unit is pivotally connected to a horizontal displacement arm. The second probe unit is pivotally connected to the first probe unit and is disposed in spaced trail position behind the first probe unit. A spacing bend is also provided in the second probe unit.

Abstract: A clutch mechanism for use in an automatic steering system is disclosed. The clutch mechanism allows an operator to manually override the automatic steering mechanism by use of the conventional steering gear. It also prevents damage to the automatic steering mechanism, which might be produced by large displacements in a steering gear feedback mechanism. Both angular and linear displacement dissipation devices are described.

Abstract: An automatic steering mechanism is provided for causing a large farm tractor or other prime mover to selectively follow a predetermined path such as a furrow previously formed in a field. It is contemplated that the prime mover is provided with a steering gear and a fluid power circuit for operating that steering gear. The automatic steering mechanism includes path sensing means such as a furrow follower mounted for deployment in a lowered position in the field furrow. A first linking assembly connects this furrow follower to a fluid power guidance valve functionally disposed in the fluid power circuit. Here, this first linking assembly interconnects the furrow follower and a valve spool. A second linking assembly interconnects the prime mover steering gear and a floating valve body. As these linking assemblies move the valve spool and valve body relative to one another, fluid flow is caused in the fluid power circuit to cause steering action.