Patent ID: 6959791

Claim:
A motor-driven disk brake having a caliper, said caliper containing: a piston for pressing a brake pad; a rotary actuator; and a rotary-to-rectilinear motion converting mechanism for transmitting rotation of said rotary actuator to said piston after converting it into a rectilinear motion; wherein said piston is driven in response to rotation of said rotary actuator to press said brake pad against a disk rotor, thereby generating braking force; said motor-driven disk brake further having a pad wear compensating mechanism for advancing said piston relative to a rectilinearly moving member in said rotary-to-rectilinear motion converting mechanism in accordance with wear of said brake pad, said pad wear compensating mechanism having a rotatable limiter engaged with a rotating member in said rotary-to-rectilinear motion converting mechanism with an amount of play in a direction of rotation such that the play provides a predetermined clearance between said piston and said pad after said pad wear compensating mechanism has achieved its wear compensation effect; wherein a resilient member is provided between the rotating member in said rotary-to-rectilinear motion converting mechanism and the limiter in said pad wear compensating mechanism, said resilient member being adapted to generate a set load greater than a non-loaded-state rotational resistance of said rotating member and to store a torque in accordance with relative rotation within the range permitted by said play between said rotating member and said limiter during braking.