STEER CONTROL FOR A TRACK-LAYING VEHICLE

• US 3,727,710 A
• Filed: 05/13/1971
• Issued: 04/17/1973
• Est. Priority Date: 05/13/1971
• Status: Expired due to Term

• Current Assignee: Jerry R. Marlow, Kenneth A. Dornfeld, Robert K. Sanders
• Original Assignee: Jerry R. Marlow, Kenneth A. Dornfeld, Robert K. Sanders
• Inventors: Sanders, Robert K., Marlow, Jerry R., Dornfeld, Kenneth A.
• Primary Examiner(s): Betts, Kenneth H.
• Assistant Examiner(s): Paperner, Leslie J.
• Application Number:
  US05/142,880
• Time in Patent Office: 705 Days
• Field of Search: 180/1R,6.2,6.5,6.7
• US Class Current: 180/6.7
• CPC Class Codes: B62D 11/08 using brakes or clutches as main steering-effecting means

Abstract

An electronic control circuit combined with an electro-hydraulic transducer regulates right and left steering clutches in a crossdrive transmission for a track-laying vehicle to effect steering by driving. The control inputs are steer lever position and track speeds so that a closed loop control is provided for controlling track speed differential as a function of actual relative track speeds.

Claims

1. A closed loop steer control for a track laying vehicle for controlling track speed differential as a function of relative track speeds comprising a pair of variable torque capacity torque transmitting devices each actuable for effecting steering by positively controlling track speed differential, steer selector means for selecting the desired degree and direction of steering, means for sensing the track speeds, and means responsive to the sensing means and the steer selecting means for simultaneously regulating the torque capacity of the devices as a function of the track speeds for establishing a track speed differential consistent with the desired degree and direction of steering.

2. A closed loop steer control for a track laying vehicle for controlling track speed differential as a function of relative track speeds comprising a pair of pressure responsive torque transmitting devices having torque capacities varying with pressure, and simultaneously actuable for effecting steering by positively controlling track speed differential, manually Operated steer selecting means for selecting the desired degree and direction of steering, means for sensing the track speeds, and pressure controlling means responsive to the sensing means and the steer selecting means for simultaneously regulating the pressures on the devices as a function of the track speeds for establishing a track speed differential consistent with the desired degree and direction of steering.

3. A closed loop steer control for a track laying vehicle for controlling track speed differential as a function of relative track speeds comprising a pair of variable torque capacity torque transmitting devices each actuable for effecting steering by positively controlling track speed differential, means associated with each device responsive to an electrical control signal for varying the torque capacity of each device, manually controlled electrical selector means for selecting the desired degree and direction of steering, electrical means for sensing the track speeds, and an electronic controller responsive to the sensing means and the steer selecting means for producing the electrical control signal and applying the signal to the signal responsive means to actuate their respective devices and for simultaneously regulating the torque capacity of the devices as a function of the track speeds for establishing a track speed differential consistent with the desired degree and direction of steering.

4. A closed loop steer control for a track laying vehicle for controlling track speed differential as a function of relative track speeds comprising a pair of variable torque capacity torque transmitting devices each actuable for effecting a track speed differential, pressure responsive means associated with each device regulated by an electrical control signal for varying the torque capacity of each device, manually controlled electrical selector means for selecting the desired degree and direction of steering, electrical means for sensing the track speeds, and an electronic controller responsive to the sensing means and the steer selecting means for producing the electrical control signal and applying the signal to one of the pressure responsive means to actuate its respective device for primarily regulating the pressure on said respective device as a function of the track speeds for establishing a track speed differential consistent with the desired degree and direction of steering, and including means for applying a signal to the other of the pressure responsive means for regulating the other of the devices at a low pressure to hold it in readiness for actuation for a reversal of track speed differential.

5. A closed loop steer control for a track laying vehicle for controlling track speed differential as a function of relative track speeds comprising a pair of selectively engageable variable torque capacity torque transmitting devices, pressure responsive means for simultaneously regulating the devices for effecting steering in one direction, electronic control means regulating the pressure responsive means for establishing a track speed differential according to a desired vehicle turning rate, the control means including manually controlled electrical selector means for selecting the direction of steering and the desired turning rate, electrical means for sensing the track speeds, means effective during an initial steering phase for effecting pressures on the regulated devices for causing a track speed differential, and means for modulating the pressure on each device according to the difference between the desired turning rate and the actual turning rate to regulate the track speed differential to that required to achieve the desired turning rate.