Patent · US Expired

Process for the gear change of automatic or synchronized mechanic transmission of motor vehicles

US4930374A · kind A · utility

18Cited by
11References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 3, 1988
Grant dateJun 5, 1990
Priority date
Expiry dateOct 3, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T74/1926
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A process for effecting controlled gear change in a vehicle having a transmission capable of automated shifting. A control circuit is provided with memory functions storing values of torque available from the vehicle engine at various operative r.p.m. values and at various throttle positions. When the vehicle is in operation, throttle position is compared to the torque/throttle position memory to derive a signal representing available torque for the throttle position. Likewise, engine r.p.m. is compared to the related memory function to derive a signal representing the torque available at such r.p.m. These two available torque values are compared to derive a signal representing relative load on the engine. A further memory function stores predetermined comparative values of load level and r.p.m. at which shifting of the transmission should occur. When load level is below a predetermined value, and simultaneously the r.p.m. is above a predetermined value, an upshift of the transmission is called for. Downshifting of the transmission is called for whenever either the load value exceeds a predetermined comparative value or the r.p.m. value drops below a predetermined comparative value…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.