| 摘要 |
<p>The master cylinder comprises a body 13 and a piston 11 having a piston head sealed with the body by a primary seal and movable in the body to pressure a high pressure chamber 25 for actuating a hydraulic device such as a vehicle clutch. The piston also has a tail portion 21 sealed with the body by a secondary seal 22. An annular low pressure chamber 49 is defined by the body and the piston between the primary and secondary seals, the body having a main feed port (18) opening into the low pressure chamber 49 for connection to a hydraulic fluid reservoir 27. The low pressure chamber 49 is divided into two portions 34, 35 by an auxiliary seal 16 which sealingly engages the body and the piston. The main feed port 18 lies between the primary seal 23 and the auxiliary seal. An auxiliary feed port 19 is provided in the body and opens into the portion 35 of the low pressure chamber 49 to connect said portion 13 to the reservoir.</p> |
