| 摘要 |
A seal for use between the piston (6) and cylinder of a hydraulic brake master cylinder comprises: an inner annular portion (2) which is located in a groove (5) in the piston (6); a web portion (4) which extends radially outwardly and axially forwardly from the inner annular portion (2); and an outer annular portion (3) which extends radially outwardly and axially forwardly from the web portion (4). The outer annular portion (3) seals against the cylinder wall during forward (arrow X) strokes of the piston. During return strokes the seal flexes about an approximate centre of flexure (14) and because the whole of the outer annular portion (3) trails behind the centre of flexure in the direction of the return stroke, the whole of the outer annular portion moves away from the cylinder wall to permit fluid recuperation.
|
