Patent ID: 6991075

Claim:
A disc brake assembly, comprising: a hub rotatable about an axis; at least a pair of brake discs supported on said hub for rotation therewith and for axial sliding movement relative to said hub along said axis and having opposite sides presenting braking surfaces; a non-rotatable support structure; a plurality of friction elements supported by said non-rotatable support structure for relative axial movement into and out of frictional braking engagement with said braking surfaces; a piston moveable from an unactuated position to an actuated position to effect said sliding movement of said plurality of friction elements and said brake discs; a primary electric actuator mounted on said non-rotatable support structure adjacent at least one of said plurality of friction elements and operative in response to a primary signal to move said piston to an actuated position and to slide said plurality of friction elements and said brake discs into said frictional braking engagement with one another, and a secondary actuator coupled operatively to said piston and operative in response to a secondary signal to move said piston to said actuated position independent of said primary signal and actuation of said primary electric actuator, wherein said secondary actuator includes a drive mechanism moveable between engaged and disengaged positions into and out of operative engagement with said piston, and wherein said drive mechanism includes a toothed rack.