Patent · US Expired

Shift control apparatus for automatic transmission

US5797821A · kind A · utility

11Cited by
5References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 4, 1996
Grant dateAug 25, 1998
Priority date
Expiry dateApr 4, 2016

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16H2061/0488
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

An automatic transmission includes a frictionally engaging element for establishing a predetermined speed range. This predetermined speed range may be a second or higher speed range, and it is set temporarily in N-D squat control and also used for establishing a reverse range. In this transmission, engagement-actuation control of the frictionally engaging element for establishing the predetermined speed range which is executed when a shift is made from a N range to a R range comprises a plurality of control stages. When a shift to the R range is made via the N range following a N-D shift, a shift control apparatus detects the engagement condition of the the frictionally engaging element for establishing the predetermined speed range, selects one of the control stages in correspondence with the engagement condition, and initiates the engagement-actuation control of the frictionally engaging element from the control stage selected, so as to execute an engagement control for establishing the reverse range. Thus, in-gear shifts are executed smoothly without any delay in a N-D-N-R range shift.

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