US Patent 10329810 Check link apparatus

A cheek link apparatus includes an arm in which a stopper portion is formed by covering a stopper core portion with a resin material and a holding member which defines a full open position of a door by being brought into abutment with the stopper portion. The stopper core portion has curved surfaces on end faces which face an abutment surface of the holding member at least when the abutment surface of the holding member is brought into abutment with the stopper portion. The stopper core position is positioned such that extensions extending in a direction in which a load is applied to the stopper core portion by the holding member pass the curved surfaces.