Safety device for sliding door

A safety device for a sliding door capable of making to-and-fro movements for covering and uncovering an opening, the device comprising a guide frame and a feed plate to be separately attached to the opening side and the sliding door side so as to be opposed to each other, wherein

• the guide frame includes
• a guide main body formed to have a C-shaped cross section having an upper wall part connecting and fixing paired front and rear side wall plate parts and upper end sides of the paired front and rear side wall plate parts and being provided with a guide passage where the feed plate passes between the paired side wall plate parts,
• a restriction groove provided to each of the paired front and rear side wall plate parts and having a slow movement groove provided to extend in a left-right direction along a direction of movement of the sliding door and a lock groove consecutively connected to the slow movement groove and having a stopper part, and
• a disk roller having a disk part and a shaft part longitudinally penetrating through a center of the disk part to be integrated with the disk part, with the shaft part being movably engaged inside the restriction grooves in a left-right direction and the disk part being placed to protrude inside the guide passage, and
• the feed plate includes
• a contact face which, when colliding with the disk part with a predetermined strength or more, moves the shaft part from inside of the slow movement groove to the stopper part of the lock groove to lock movement of the disk roller in the left-right direction and inhibit the feed plate from moving together with the sliding door to a closing side.