| 摘要 |
<p>Assistance in erection, and facility in turning, are provided by a hingeing device at the bottom of a pref. transportable and telescopic mast, with a U-shaped holder (5) mounted on a spherical face (3) on a base plate (2). The centre hinge shell (6) on the holder has an elongated guide slit (8) for a screw (4). The length of this slit is double screw dia. on the shell's hinge surface. The line of the slit is parallel to that of the hinge bolt (10) providing swivelling mounting for the mast foot (a). This provides easy mounting and lowering for a mast bearing a light, radar screen, antenna or other appliance.</p> |
