| 摘要 |
The bollard (1) is retracted below the level of the surrounding surface (12) when not in use, inside a housing (2) with an inner sleeve (3) and a cartridge (4) containing its drive mechanism. The drive is in the form of a piston (5) connected to a pneumatic bellows which is inflated by air fed through a tube (6) to deploy the bollard, and released to retract it. The housing is covered by a cap with an aperture for the bollard to pass through, and the gap between the housing and sleeve contains cables (31) and pneumatic tubes for the drive. The sleeve also contains a sensor (13) which is linked to an indicator showing whether the bollard is retracted or deployed. |
