LIMIT SWITCH FOR OVERHEAD DOOR COLLISION DETECTION AND OVERHEAD DOOR USING THE SAME

摘要

The present invention relates to an overhead door that sounds an alarm to prevent a collision between the door and a vehicle when the door moves up or down, and controls the movement thereof. A limit switch for preventing the collision of the overhead door according to the present invention includes a driven shaft rotating in linking with a drive motor; a movable contact member which is coupled to the driven shaft and moves in the lateral direction of the driven shaft; a moving-up end switch that comes into contact with the movable contact member at the position of the driven shaft corresponding to a maximum moving-up point of a shutter; a moving-down end switch that comes into contact with the movable contact member at the position of the driven shaft corresponding to a maximum moving-down point of the shutter; and an alarm end switch that comes into contact with the movable contact member at the position of the driven shaft corresponding to an alarm end point of the shutter. The moving-down end switch and the alarm end switch are positioned in order so that the movable contact member is brought into contact with the alarm end switch and then moving-down limit switch when the shutter moves down. Therefore, since a warning light is turned on when the shutter is not fully opened, a driver or an assistant can recognize correct entrance time/exit time into/from a garage or warehouse even though the driver or the assistant does not visually check the open state of the shutter, thereby preventing a collision between the shutter and the vehicle.