摘要 |
A cylinder (10) and piston (14) device has a piston (14) with a circumferential fluid seal mounting band (17) near one of its ends, a step (19) defining a piston end portion (20) of smaller diameter than the band (17), and a snap-ring groove (21) in the end portion (20) near the step (19). A stressed fluid seal (22) which is mounted on the band (17) has an unstressed diameter (across 25) less than that of the band (17) but greater than that of the piston end portion (20); and a retaining ring (27) for the fluid seal (22) is held adjacent the step (19) by a snap-ring (28) in the groove (21). |