Synchromesh transmission suited for use as automotive automatic transmission

A transmission comprising:

• an input shaft operatively connected with a source of rotational energy;
• a first intermediate shaft arranged to be coaxial with said input shaft;
• a first clutch for selectively providing a drive connection between said input shaft and said first intermediate shaft;
• a second intermediate shaft arranged to be coaxial with said input shaft;
• a second clutch for selectively providing a drive connection between said input shaft and said second intermediate shaft;
• a countershaft arranged to be parallel with said input shaft;
• a first group of intermeshing input and output gears arranged between said first intermediate shaft and said countershaft to provide a first predetermined speed change ratio;
• a second group of intermeshing input and output gears arranged between said second intermediate shaft and said countershaft to provide a second predetermined speed change ratio;
• output means for connection with said countershaft to transmit power from the countershaft to an external drive means;
• a primary means which comprises a first input gear rotatably disposed about said first intermediate shaft, a first synchronizer-clutch arranged between said first input gear and said first intermediate intermediate shaft to selectively connect and disconnect said first input gear and said first intermediate shaft and a first output gear secured to said countershaft and constantly meshed with said first input gear to rotate therewith;
• a secondary means which comprises a second input gear rotatably disposed about said second intermediate shaft, a second synchronizer-clutch arranged between said second input gear and said intermediate shaft to selectively connect and disconnect said second input gear and said second intermediate shaft and a second output gear secured to said countershaft and constantly meshed with said second input gear to rotate therewith,
• wherein said primary and secondary means are constructed to individually provide between said input shaft and said countershaft a common speed change ratio.