Patent ID: 7506733

Claim:
A Ball-In-Ramp brake caliper type parking brake for a vehicle, comprising: a parking unit that generates an operation force to uniformly pull a parking cable by an equalizer when a parking lever is operated; a caliper housing that includes an inner liquid pressure chamber filled with brake oil generating liquid pressure, and pads provided to cover both surfaces of a disk plate provided in a wheel; a cartridge assembly that protrudes to the outside of the caliper housing so as to be connected to a parking operation force input unit connected to the parking cable, is provided in the liquid pressure chamber, and includes ball movement grooves having variable paths so that an axial force is gradually increased as movement trajectories of balls are gradually decreased in a radial direction so as to be shortened with respect to an axis, when the cartridge assembly is rotated, balls moving from central portions of the movement trajectories to end portions of the movement trajectories; and a pad wear compensator that is assembled to the cartridge assembly in the liquid pressure chamber of the caliper housing, and presses the pads against both surfaces of the disk plate when the cartridge assembly moves in an axial direction, wherein the cartridge assembly includes: an input ramp that is rotated by the parking operation force input unit of which one end is connected to the parking cable outside the caliper housing; an output ramp that is provided at a side opposite to the input ramp, and generates an axial force pushing the pads toward the disk plate when the input ramp is rotated; and a ball case housing that is provided in the ball movement grooves having the variable paths formed on the input and output ramps, and gradually increases the axial force of the output ramp as balls having movement trajectories along the ball movement grooves move from the central portions to the ends portions during the rotation of the input ramp, wherein the ball case housing is composed of a ring-shaped ball restricting plate that has a hole at the center thereof, ball movement holes are partially opened at the circumferences thereof and formed on the ball restricting plate at constant intervals, and each of the balls is fitted into the ball movement hole so as to move in the radial direction; and each of the ball movement holes has a length larger than a diameter of the ball so that the ball linearly moves in the radial direction, and has a ball restricting entrance, which has a diameter smaller than the diameter of the ball, at the end thereof so as to prevent the ball from being separated from the ball movement hole.