| 摘要 |
A gate structure has a gate 14, hinged about a horizontal axis 15, within a gateway 10 (Fig. 2) and the gate is positively and controllably moved between closed and open positions by links 16 connected to each side of the gate, which links are driven by endless chains 17 and are provided with rollers 18 cooperating with tracks 19 to ensure smooth rectilinear movement of the links. The endless chains 17 are driven by a motor 20 through line shafting 21 and gearing 22. <IMAGE> |
