| 摘要 |
The gate (4), of e.g. light alloy construction, is driven across the gateway by rack-and-pinion gear operated by an electric motor (2) in the pillar base (1). Passage through the gateway, when open, is controlled by a lifting barrier (6), raised and lowered by another motor (5), through suitable gearing. The electricity supply to both motors is controlled by switchgear, relays, etc., in a control compartment (3), also within the pillar. Control may be conventionally electromechanical, or subjected to an automatic time-based programme.
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