Patent ID: 6957534

Claim:
A master cylinder for a hydraulic disc brake comprising: a housing defining a cylinder, the cylinder having a first and second end along its axis; a piston received in the cylinder, the piston having a radial seal between the piston and cylinder; a lever pivotably associated with the housing for pivoting between a rest position and an actuated position relative to the housing; a push rod operatively associated with the piston and the lever to move the piston axially within the cylinder as the lever is actuated between the rest and actuated position; a threaded engagement between a first end of the push rod and the lever, the threaded engagement being configured to cause movement of the rest position of the lever relative to the housing when a rotating force is applied to the push rod causing axial rotation of the push rod; a first set of protrusions operatively associated with the push rod to rotate axially with the push rod; a second set of protrusions nesting with the first set of protrusions, the second set of protrusions being fixed against rotation relative to the push rod when the rotating force is applied to the push rod; and biasing means operatively associated with at least one of the first and second sets of protrusions to bias the protrusions into nesting engagement with the other inhibiting relative axial rotation therebetween.