Patent ID: 7909415

Claim:
A locking master cylinder assembly for supplying pressurized hydraulic fluid through a brake line to operate a vehicle brake, the locking master cylinder assembly comprising: a) a housing having a reservoir for containing the hydraulic fluid, a first internal bore in fluid communication with said reservoir, a second internal bore, a passage for providing fluid communication between said first internal bore and said second internal bore and an outlet port in fluid communication with said second internal bore and with the brake line; b) a first reciprocating piston movable within said first internal bore, wherein said first reciprocating piston is for pressurizing the hydraulic fluid to engage the vehicle brake in response to input from a vehicle operator; c) a lid disposed on said housing; d) a second reciprocating piston movable within said second internal bore; and e) a locking lever pivotally coupled to said lid, said locking lever comprising a rounded camming surface portion in abutting contact with said second reciprocating piston for actuating said second reciprocating piston; wherein said locking lever is moveable between a first position, wherein the hydraulic fluid can flow freely between the first internal bore and the brake line for engaging and disengaging the vehicle brake and a second position, wherein the hydraulic fluid is prevented from returning to the first internal bore for maintaining the vehicle brake in an engaged state; said locking lever further comprising a projecting tab for retaining said locking lever in said second position and a flattened surface portion adjoining said rounded camming surface portion, said flattened surface portion in abutting contact with said second reciprocating piston when said locking lever is in said second position.