| 摘要 |
<p>The pivoting barrier has a rail on anhoirzontal axis, swung up and down by an actuator. In the lengthwise direction of the rail (13) there are elastic components such as coil springs (16, 17) acting at points clear of the axis (14) so as to absorb the rail weight the whole time it is moving. There may be levers (1819) fixed to opposite ends of the axis, and to whose free ends the springs etc. are attached, the tractive force exerted by the latter being adjustable. One of the levers can be double armed, the end not attached to the spring being coupled by a rod to an eccentric lever on an electric motor in the column (10).</p> |
