Patent GB-1268181-A (GB)
Title: An automatically controlled agricultural machine
Inventor: RICHARDSON BERNARD
IPC: A01B69/04
Filed: 1968-03-20
Abstract: 1,268,181. Automatic agricultural machine. B. RICHARDSON. 13 March, 1969 [20 March, 1968; 4 Dec., 1968], Nos. 13489/68 and 57622/68. Heading B7H.  A machine for carrying out agricultural field operations works automatically when set up for operation, is reversible and self-propelled, and has mechanism at each end for mounting an implement, e.g. plough 30, power steering mechanism under the control of a guiding sensor 50, and reversing and sidetracking mechanism under the control of a reversing sensor or sensors, e.g. wheel 46B and probe 68, responsive to means indicating the end of a line of work whereby the machine may be reversed at the end of a line of work and moved to a new line of work. Fig. 2 shows only one such arrangement at one end for the sake of simplicity. A sensor comprises feelers 52 which are arranged across a furrow 17, each sensor is connected to an hydraulic valve (54), Fig. 4 (not shown). In operation, if the machine veers to one side such that feeler 52C enters furrow 17, the sensor operators its valve which is connected to a steering ram which controls a variable displacement pump 16 which supplies fluid to a main wheel motor. Change of fluid flow to the motor will make the machine veer to the left until feeler 52C contacts the soil. Feelers A, B and C are connected to pump 16, feelers D, E and F are connected to a pump 18 which drives a motor on the other side of the machine. A reversing sensor, wheel 46B, is connected to an arm 48 whereby when the machine reaches the end of a field vertical movement of the arm, through meeting a bank or ditch, operates a valve or switch 66 which initiates the reversing procedure. Rotation of the wheel 46B keeps a valve or switch 64 open or closed whereby if the wheel stops, except during the reversing procedure, the engine 14 of the machine is stopped. A probe 68 on contacting a fence or hedge will also start the reversing procedure. Other ways of initiating the reversing procedure could be: a photo-electric cell operated by light reflected from a special fence; a signal from a wire laid in the soil; from a layer of magnetic powder inserted into the soil and identified by a sensing head on the machine. More delicate sensing devices could be used. The reversing procedure can take three forms which may be controlled by a logical sequence of valves or by a timer: if the sensor is wider than the implement a straight reversal is carried out; if the sensor is narrower than the implement the machine is slewed one way, reversed, and then slewed back to travel parallel to the original line of travel; or if the sensor is narrower than the implement and the machine has jacking apparatus then this is used to move the machine at right angles to the direction of travel. The jacking apparatus comprises a plate 38, one at each end of the machine (only one being shown), connected to rams 36A-36C and having a sidetracking ram 42. The machine can have a side mounted spring loaded device on the side nearer the work to be done, which, on contact with anything will operate to switch off the engine. Thus a part could be erected in a field where the work will end. Fail safe devices may be incorporated to stop the machine, for example, due to excessive wheelspin, excessive angle of heel or chains.