Electric caliper brake

An electric caliper brake which comprises a carrier having a pair of pad plates movably with respect to a disk, and a caliper housing slidably installed on the carrier and having a cylinder in which a piston is movably provided by braking oil pressure , the electric caliper brake comprising:

• a spindle member which penetrates a rear portion of the cylinder and rotates by receiving a rotational force from an actuator;
• a power converting unit including a nut member, wherein the nut member is screwed with the spindle member and disposed in the piston so as to move forward and backward in accordance with the rotation of the spindle member to press the piston;
• a filling member coupled to the nut member in the piston;
• an anti-rotation surface on at least one plane on an outer circumferential surface of the filling member so that the filling member is coupled to the piston in a limited rotation state;
• a stopper projection protruding from one surface of the spindle member in a circumferential direction toward the nut member;
• a stepped portion disposed on the nut member and engaged with the stopper projection when the stopper projection rotates;
• and
• a backup protrusion disposed on the filling member and engaged with the stopper projection when the stopper projection rotates,
• wherein the stepped portion and the backup protrusion facing the stopper projection are disposed at different angles.