| 摘要 |
In a power-assisted chain drive actuator for opening and closing gating fixtures, a drive chain has successive links formed of pairs of plates being parallel and swivel connected to each other by crosswise studs having an increased middle diameter holding the plates apart; the chain is also provided with members for limiting the relative angular displacement of adjacent links in the chain; between the middle increased diameters there engage the teeth of a drive sprocket; the limiting members prevent the chain from becoming deflected in the direction of its remote side from the drive sprocket past a position of substantially straight alignment of the links and take up the bending couples on the chain on application of a push force to a fixture leaf. |
