Automatic transmission
US4916977A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1987 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Aug 6, 2007 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H37/042
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Automatic transmission including a main-transmission-mechanism consisting of two planetary gear units (three speed or four speed transmission mechanism for example) and a sub-transmission-mechanism consisting of one planetary gear unit (underdrive mechanism, for example). One speed and two speed for the whole transmission are obtained, with a low speed stage of the main-transmission-mechanism lower than two speed, by shifting the main-transmission-mechanism to one and two speed, respectively, while the sub-transmission-mechanism is kept at low speed (underdrive). And three speed for the whole transmission is obtained by shifting the sub-transmission-mechanism to high speed (direct coupling) while the main-transmission-mechanism is left at the two speed state. Further, four speed or five speed for the whole is obtained by shifting the main-transmission-mechanism to three speed or, if it is of four speed type, to four speed, respectively, while the sub-transmission-mechanism is kept at the high speed state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.