| 摘要 |
A master cylinder (10) includes a housing (24) defining a bore (26) therein and a fluid reservoir (38) communicating with the bore via a passage (30). A stepped piston (94) is reciprocably received in the bore and cooperates with the housing to define a pair of variable-volume pressure chambers (108, 110). An annular valve apparatus (106) circumscribes the stepped piston within the housing bore and sealingly cooperates with the stepped piston and housing to bound the pair of variable-volume pressure chambers. The valve apparatus is pressure responsive to control fluid communication between the pair of pressure chambers and through the passage. |
