Patent ID: 7779970

Claim:
A brake assembly for braking a wheel of a bicycle, the bicycle including a frame body, the wheel having a magnetically attractive wheel rim which surrounds a wheel axis in an axial direction and which has left and right rim sides, said brake assembly comprising: left and right brake arms respectively including left and right pivot ends adapted to be pivotally mounted on the frame body about left and right pivot axes, respectively, which are transverse to the axial direction, and left and right mount segments which respectively extend from said left and right pivot ends in an upright direction and outboard of the wheel rim such that, by virtue of a braking action, said left and right mount segments are moved from a normal position, where said left and right mount segments are remote from the wheel rim, to a mechanically braking position, where said left and right mount segments are close to the wheel rim; left and right holders respectively mounted to said left and right mount segments, and extending respectively along left and right lengthwise lines to terminate at left and right anchored ends, respectively, said left and right anchored ends being elongated in a direction transverse to the upright and axial directions, and respectively forming left and right anchored regions that are disposed to be respectively spaced apart from the left and right rim sides in the axial direction; left and right pad units which are respectively mounted on said left and right anchored regions, and which respectively have left and right friction surfaces that are disposed to be respectively spaced apart from the left and right rim sides when said left and right mount segments are in the normal position, and that are brought to frictionally engage the left and right rim sides, respectively, thereby effecting a braking action on the wheel rim when said left and right mount segments are in the mechanically braking position; and left and right magnetically attracting units respectively mounted on said left and right anchored regions, confronting each other in the axial direction for establishing a magnetic field, and disposed to be respectively spaced apart from the left and right rim sides in the normal position such that strength of the established magnetic field is insufficient to generate a dragging force on running of the wheel rim, and such that, in the course of the braking action, the strength of the established magnetic field is gradually increased to be of a magnitude sufficient to generate a dragging force to decelerate the running speed of the wheel rim until the mechanically braking position is reached.