Patent ID: 9568026
Date: 2017-02-14
CPC Classifications: B60T,F15B

Claim:
1. An electric motor-driven booster comprising an input member movable to advance and retract in response to an operation of a brake pedal; a boosting member provided to be movable relative to the input member, the input member being abuttable against the boosting member when the input member advances; an electric motor-driven actuator adapted to drive the boosting member, an operation of the electric motor-driven actuator being controlled based on movement of the input member so as to adjust relative positions of the input member and the boosting member to generate a brake hydraulic pressure in a master cylinder with a desired boost ratio; a spring device disposed between the boosting member and the input member and configured to bias the input member against the booster relatively in a rearward direction; a movable spring retainer that is disposed closer to the brake pedal than the spring device and is configured to abut against the input member when the input member advances to near where an output of the electric motor-driven actuator reaches a predetermined maximum output; and a reaction force spring configured to bias the input member through the movable spring retainer toward the brake pedal with the input member and the movable spring retainer contacting each other.