Patent ID: 8413768

Claim:
An anti-lock brake structure adapted to be disposed on a wheel rim of a vehicle, the anti-lock brake structure comprising: a brake base having a curved guiding portion longitudinally formed on a lateral side of the brake base; a slidable holder movably receiving the brake base, the slidable holder having a curved guiding groove defined therein, the curved guiding groove corresponding to the curved guiding portion of the brake base for receiving the brake base; two anti-lock inclined surfaces positioned between the curved guiding portion of the brake base and the curved guiding groove of the slidable holder, each anti-lock surface having a shallow section and a deeper section located adjacent to the shallow section, the shallow section gradually sloping toward the deeper section along a rotating direction of the wheel rim; two wheel sets disposed between the curved guiding portion of the brake base and the curved guiding groove of the slidable holder, the two wheel sets respectively and movably abutting against the two anti-lock inclined surfaces, wherein when the slidable holder moves relative to the brake base, each wheel rolls and reciprocates between the shallow section and the deeper section; a seat member connected to the slidable holder and having a receiving space defined therein; a positioning sleeve connected the seat member with the slidable holder, the positioning sleeve having a positioning hole defined therein, an assisting sleeve coaxially and movably received in the positioning hole, the assisting sleeve having a plurality of apertures defined in an outer periphery thereof, an assisting member disposed in each aperture, a positioning shaft coaxially and slidably received in the assisting sleeve, wherein when the positioning sleeve moves relative to the positioning shaft, the positioning shaft simultaneously drives the assisting members to roll and the assisting sleeve is driven to move by the assisting members; an elastic member compressibly received in the receiving space of the seat member to adapt to provide a biasing force on the slidable holder; and a brake shoe connected to the slidable holder for adapting to pressing against the wheel rim of the vehicle.