Row crop harvester guidance system control circuit

• US 4,505,094 A
• Filed: 09/06/1983
• Issued: 03/19/1985
• Est. Priority Date: 09/06/1983
• Status: Expired due to Fees

• Current Assignee: Deere & Company Moline IL A Corporation of
• Original Assignee: Deere & Company
• Inventors: Demorest, Donald W.
• Primary Examiner(s): Mancene, Gene
• Assistant Examiner(s): Tarnoff, David L.
• Application Number:
  US06/529,429
• Time in Patent Office: 560 Days
• Field of Search: 56/10.2, 56/14.9, 56/15.1, 56/15.2, 56/15.3, 56/15.4, 56/15.5, 56/DIG. 15, 180/79.1, 180/131, 180/132, 104/244.1, 280/776
• US Class Current: 56/10.20F
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: A01D 41/1278 for automatic steering
• CPC Class Codes: Y10S 56/15 Condition responsive

Abstract

A row crop harvester guidance system control circuit comprises a control valve for actuating a hydraulic cylinder connected to the tongue of a pull type harvester responsive either to first and second row crop sensing units mounted on opposite sides of a crop receiving passageway of the harvester or to a manual override switch. The row crop sensing units operate respectively a pair of sensor switches connected in circuit with the control valve. To prevent simultaneous generation of signals by both of the sensor switches, a pair of relays are connected in circuit with the sensor switches and the control valve. The manual override switch is connected in circuit with the relays and generates a control signal for operation of the hydraulic cylinder. The control signal has priority over any contradictory signal generated automatically by either of the sensor switches.

Claims

1. In a guidance system for a towed row crop harvester, said harvester comprising a crop receiving passageway, a base unit and a tongue pivotally mounted to said base unit, said system comprising:

a hydraulic cylinder connected between said tongue and chassis;

a valve for actuating said cylinder to pivot said tongue and base unit relative to each other and having a valve actuating solenoid;

first and second sensing units mounted on opposite sides respectively of said passageway;

first and second sensor switches actuable respectively by said first and second sensing units;

the improvement comprising;

a first relay including a first normally closed relay switch and a first relay coil, said first relay switch connected in circuit between said solenoid and said first sensor switch;

a second relay including a second normally closed relay switch and a second relay coil, said second relay switch connected in circuit between said solenoid and said second sensor switch;

said first sensor switch in circuit with the second relay coil to energize said coil and open said second relay switch when said first sensor switch is closed;

said second sensor switch in circuit with the first relay coil to energize said first relay coil and open said first relay switch when said second sensor switch is closed; and

a manually actuable switch selectively connectible in circuit with said solenoid and said first relay coil so as to energize said solenoid and said first relay coil and with said solenoid and second relay coil so as to energize said solenoid and second relay coil.

2. The system of claim 1:

further comprising first and second diodes respectively connected in parallel with said solenoid;

wherein said first diode is connected in circuit between said manual switch and said second relay coil; and

wherein said second diode is connected between said manual switch and said first relay coil.