Transmission clutches with fully-resetting modulator-load-piston
US4216851A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 24, 1978 |
| Grant date | Aug 12, 1980 |
| Priority date | — |
| Expiry date | Mar 24, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16D2048/0221
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A multi-functioning hydraulic transmission control circuit including interacting valve mechanism parts which, in response to a shift being called for in a clutch-cylinder-controlled multi-speed transmission, inaugurate a fill pressure flow to the clutch cylinders concerned, prior to the subsequent fluid pressure rise effected therein; thereafter, upon completion of the fill, the parts modulate pressure rise of the hydraulic clutch fluid from and at approximately actual clutch fill pressure up to, and remaining at, the final pressure of engagement. These functions including full resetting of the parts at the beginning of each shift, and 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 d…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.