All-electric A.C. tractor

Patent 4196785 Issued on April 8, 1980. Estimated Expiration Date:

September 11, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3481417

3577050

3584276

3690395

3713504

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3860081

3870935

Inventor

Downing, Jr., James H.

Application

No. 05/941358 filed on 09/11/1978

US Classes:

180/6.28, Electrical180/65.4, Generating means is driven by a prime mover318/52, Slipping and/or racing control for electric motors318/68, Relative motor speed control318/721, Responsive to rotor shaft position or speed318/807, Frequency control414/526, Screw type903/905, Combustion engine (EPO/JPO)903/916, With plurality of drive axles (EPO/JPO)903/925, Series (EPO/JPO)903/942Control of motor or generator (EPO/JPO)

Examiners

Primary: Peters, Joseph F. Jr.
Assistant: McGiehan, Donn

Attorney, Agent or Firm

Sughrue, Rothwell, Mion, Zinn and Macpeak

International Classes

B60L 11/08 (20060101)
B60L 15/20 (20060101)
B60K 6/00 (20060101)
B60L 11/02 (20060101)
B60K 6/04 (20060101)
B62D 49/00 (20060101)
B62D 49/06 (20060101)

Abstract

An electronic differential speed control circuit for driving the inboard and outboard A.C. wheel motors at different relative speeds depending upon the steering angle during a turn. An electrical circuit for sensing the torque of the tractor's wheel motors to maintain a constant implement draft. A hollow tubular axle pivots around the tractor's longitudinal material-transferring tunnel to conserve space and permit mounting of the wheel motors within the axle. The tunnel has two material-transferring compartments or passageways, and has vertically movable extensions on either end to facilitate coupling to accessories. An electrical power outlet is provided for energizing non-motor driven accessories.

Other References

"An A-C Individual Wheel Drive System for Land Vehicles", by Walter Slabiak, U.S. Army Tank-Automotive Center, pp. 664-671, Document 660,134 (undated)
"Precise Control of a 30 Squirrel-Cage Induction Motor Using a Practical Cycloconverter", Slabiak and Lawson, IEEE Trans. on Industry & Genl. Aplications, vol. 2, No. 4, Jul.-Aug. 1923
"Optimal Control System Performance for an A-C Electric Drive", Lawson et al, Power Equipment Div. Lear Siegler, Inc. Document 660,135 (undated)
"Le Tourneau Letro-Stacker", Product Circular, dated Sep. 1969