Patent · US Expired

Modulated transmission with modulator-load-piston loading at linear rate after full reset

US4387731A · kind A · utility

5Cited by
19References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 29, 1981
Grant dateJun 14, 1983
Priority date
Expiry dateOct 29, 2001

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/8158
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A multi-functioning hydraulic transmission control circuit in which a shifting power is provided by hydraulic pressure. The multi-functions including full resetting of the parts at the beginning of each shift, also including, according to some variations hereof as disclosed, a constant rate of rise irrespective of cylinder leakage make-up through the fill orifice and irrespective of graduality of the pressure rise desired, and additionally including a lesser and a least gradual pressure rise afforded during respective second and third speed upshifts, are all accomplished by and among a pair of direction-selector and orificed-speed-selector valve spools connected to the transmission clutch cylinders to direct valve fluid output thereto selectively, and also 1st, dump valve 2d, simulated clutch piston, 3d, load piston, 4th, modulator valve, and 5th, interacting spring parts collectively providing said directed valve fluid output, all in a valve bore common thereto, and arranged therein with the dump valve part confronted at one side by the simulated clutch piston part so as to define mutually therewith a differential pressure chamber in the bore, and confronted at the other side by f…

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