Patent ID: 7370744

Claim:
A friction engagement device of an automatic transmission having a piston actuated by an oil pressure to press a friction disc with the piston, comprising: an oil pressure chamber formed to extend in an annular shape; and a plurality of oil paths each extending separately to supply oil to said oil pressure chamber; wherein each of said plurality of oil paths connects to said oil pressure chamber in a position different from each other in a circumferential direction of said oil pressure chamber, wherein said plurality of oil paths include a first oil path having a relatively short length and a second oil path having a relatively long length, said first oil path is formed to let oil flow therethrough with a relatively large resistance, and said second oil path is formed to let oil flow therethrough with a relatively small resistance, wherein said relatively large resistance and said relatively small resistance are selected such that different application timings of the oil pressure to said oil pressure chamber do not occur due to the differences in length of said relatively long length of the second oil path and said relatively short length of the first oil path.