SELF-CLOSING DEVICE FOR SLIDING DOOR

PROBLEM TO BE SOLVED: To immediately and surely remove slack, when the slack is caused in a wire, in a self-closing device for sliding door. SOLUTION: The self-closing device for sliding door A comprises a weight unit W formed by incorporating, to a spring case 25, a rotatable wire reel 30 for winding a wire 19, a spiral spring 25 which regularly rotationally energizes the reel in the winding direction of the wire, and a rotary damper 45 which reduces the rotating speed of the wire reel, when self-closing a sliding door D, to give a braking force to the sliding door. The sliding door includes a guide hole 60 for guiding the weight unit downward from an upper end surface 11 of the sliding door. The weight unit is set so that the gravity acting thereon is smaller than the rotational energizing force of the spiral spring, and the wire is unwound from the wire reel and stored within the guide hole in a suspended state to be movable upward and downward with a top end thereof being engagingly locked by a support body of the sliding. When the wire unwound from the wire reel loosens during closing, the weight unit moves down in the depth direction of the guide hole by the portion corresponding to the slack to remove the slack. COPYRIGHT: (C)2009,JPO&INPIT