Patent ID: 7328777

Claim:
A disc brake system driven by a rack, comprising: a caliper body; an activating brake shoe linearly and slidably installed in said caliper body; a motor installed in said caliper body; a driving gear installed at a rotational shaft of said motor; a rack meshing with said driving gear and linearly moving in a perpendicular direction to a brake disc; and self boosting means disposed between said rack and activating brake shoe for transmitting force of said rack to said activating brake shoe, wherein said self boosting means compresses said activating brake shoe toward said brake disc by force provided from said rack and brake disc, wherein said self boosting means includes: an oblique shoe surface that is formed at said activating brake shoe to face said rack and make an inclination against a flat surface of said brake disc; and a pressure plate having at both sides thereof an input surface, which contacts perpendicularly to a moving direction of said rack, and an output surface that is parallel to said oblique shoe surface; wherein said output surface of said pressure plate is further formed with a contact protrusion that faces and contacts said oblique shoe surface.