Control system for maintaining traction in a rolling stock
CA 1252182 A · Owner: Hitachi Ltd. · Inventors: Kimura, Akira; Hirotsu, Tetsuji; Narita, Hiroshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract:, An improved control system ensures more effective utilization of the frictional force between the wheels of rolling stock and the rails. From a peripheral velocity vM of a driving wheel and a vehicle velocity v the rate of change, .DELTA.vs/.DELTA.t of the relative velocity vs with respect to time is obtained. The rate of change .DELTA.f/.DELTA.t of the traction force f produced in the driving wheel at that time is obtained from a detected armature current of a motor driving the driving wheel. The driving torque produced by the motor is so controlled as to decrease when the polarities of the rate of change of the relative velocity and that of the traction force are different from …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted April 4, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 4, 2006.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.