Patent ID: 6705435
Filing Date: 2004-03-16
Classification: F16D

Abstract:
A disc brake, particularly for a heavy road vehicle, having a caliper arranged in the vicinity of at least one brake disc mounted on a wheel axle of the vehicle, comprising: a thrust rod for transforming a rotational ingoing movement from a drive means into a linear outgoing movement for transmission to a disc brake pad, intended for braking engagement with the at least one brake disc, the thrust rod having a non-rotatable member, a rotatable nut member in thread engagement with the non-rotatable member, a thrust rod gear for receiving the ingoing rotational movement, and a biased roller and ramp arrangement operationally interposed between the nut member and the thrust rod gear for rotating the nut member on the non-rotatable member at a low counterforce in the non-rotatable member during an earlier stage of brake application where contact between the disc brake pad and the brake disc has not been established, and for axially transferring the nut member with the non-rotatable member at a high counterforce in the non-rotatable member during a later stage of brake application after contact between the disc brake pad and the brake disc has been established, wherein the non-rotatable member is a spindle, on which the nut member is arranged, wherein the thrust rod gear is rotatably arranged on the nut member and rollers with axes radial to the spindle are arranged between radial parallel ramp surfaces, having a pitch or inclination and being arranged on the thrust rod gear and the nut member, respectively, wherein the roller and ramp arrangement is spring biased, wherein the thrust rod gear and the nut member are biased against each other by means of a compression spring, and characterized by means for transmitting the force of the compression spring to the nut only in the rotational direction of the latter for a return stroke of the disc brake.