Patent ID: 6918157

Claim:
A rail structure for doors, comprising: a track rail body ( 3 ) which supports door wheels ( 4 ) which are attached to a door ( 6 ) such that the door wheels ( 4 ) freely run on the track rail body ( 3 ); a load support member ( 2 ) extending alone the track rail body ( 3 ) and supporting the track rail body ( 3 ) from the bottom thereof; a convexo-concave fitting part ( 8 ) which is formed on a bottom surface of the track rail body ( 3 ) and an upper surface of the load support member ( 2 ), the convexo-concave fitting part ( 8 ) fitting in the state of convexo-concave fitting; and a cushion member ( 7 ) for absorbing vibration from the track rail body ( 3 ), the cushion member ( 7 ) being disposed between the track rail body ( 3 ) and the load support member ( 2 ), wherein the track rail body ( 3 ) is attached to the load support member ( 2 ) detachably, the convexo-concave fitting part ( 8 ) includes a convex part ( 3 a ) and a concave part ( 2 a ) such that the convex part ( 3 a ) which extends along the continuing direction of the track rail body ( 3 ) is formed on either side between the bottom surface of the track rail body ( 3 ) and the upper surface of the load support member ( 2 ), and in such a way that the concave part ( 2 a ) which is groove-shaped and extends along the continuing direction of the track rail body ( 3 ) is formed on the other side between the bottom surface of the track rail body ( 3 ) and the upper surface of the load support member ( 2 ), an interface of surfaces which face each other in addition to the convexo-concave fitting part ( 8 ) is formed on the bottom surface of the track rail body ( 3 ) and on the upper surface of the load support member ( 2 ), the cushion member ( 7 ) is put in the convexo-concave fitting part ( 8 ) and the interface of surfaces between the track rail body ( 3 ) and the load support member ( 2 ), a width dimension B of a middle part of a depth direction of the groove of the concave part ( 2 a ) is larger than a width dimension A of margin of the groove, a side face of the groove is in the form of circular section in the state of concave shape, the convex part ( 3 a ) is in the sectional shape corresponding to the concave part ( 2 a ), a width dimension C of the middle part of a height direction of the convex part ( 3 a ) is larger than a width dimension D of a neck part, the side face of the convex part ( 3 a ) is in the form of circular section in the state of convex shape, the width dimension C is smaller than the width dimension A, a thickness dimension E of the cushion member ( 7 ) is larger than half a difference between the width dimension A and the width dimension C, and the cushion member ( 7 ) is board-shaped, elastically deformable material.