| 摘要 |
PURPOSE:To perform smooth control of elevation through simple control, by a method wherein an input shaft is axially movable, a male screw part is formed on an outer peripheral surface, a gear is engaged, and a one-way rotary member, a brake device, and a release member are provided. CONSTITUTION:When an input shaft 3 is pushed to the case 1 side through operation of a control handle 6, a male screw part 7 on the input shaft 3 is threadedly joined with a femal screw part 14 of a pinion 11 to wind up a door body. A one-way clutch 25, mounted to a brake drum 26, prevents rotation in a wind-down direction of the door body to prevent drop of the door body. A control lever 78 is depressed, and the brake force of a block brake 28, adapted to brake rotation of the brake drum, is reduced to cause the door body to drop under gravity. This enables simple and smooth control of elevation of a gate door through shift control effected by pushing and pulling the input shaft, and permits reliable prevention of drop of the water gate door. |
