Patent ID: 6971485

Claim:
In a disc brake having a support member secured to a vehicle, said support member having first and second guides to align a caliper over a rotor associated with a wheel of a vehicle, said caliper having an actuation section connected by a bridge to an arm, said actuation section having a bore therein for retaining a piston to define an actuation chamber, a first friction member connected to said piston and a second friction member connected to said arm, said actuation chamber on being presented pressurized fluid from a source acting on said piston and actuation section to develop a dynamic clamping force for moving said first and second friction members into engagement with said rotor to effect a brake application, and said piston being prevented from rotating with respect to said second friction member by means of anti-rotation members engaged with said piston, a locking mechanism characterized by having a first threaded member integrally attached to said piston, a second threaded member able to rotate in said bore and having a plurality of teeth located at a closed end of said bore, and means for moving a third member into engagement with said teeth on second threaded member to affect a parking brake application by preventing rotation of said second threaded member and thereby holding said friction members in engagement with said rotor, said second threaded member being retained in the closed end of said bore by a retaining ring located in a groove in said bore and holding a preloaded wave washer against a bearing thrust washer to hold a first thrust bearing against a first face of said second threaded member adjacent to said piston, and a second thrust bearing engaging a second face of said second threaded member located adjacent the closed end of said bore, said second threaded member rotating as said piston moves said friction members into engagement with said rotor.