Brake operating mechanism

Claim 1

A PRESSURE GENERATING MECHANISM FOR MOTOR VEHICLE BRAKES COMPRISING A MASTER CYLINDER, A PRIMARY PLUNGER PROJECTING INTO ONE END OF SAID MASTER CYLINDER, A SECONDARY PLUNGER IN SAID MASTER CYLINDER BETWEEN SAID PRIMARY PLUNGER AND THE OTHER END OF SAID MASTER CYLINDER, SAID PLUNGERS FORMING THEREBETWEEN A PRIMARY CHAMBER CONNECTED TO ONE SET OF WHEEL CYLINDERS, SAID SECONDARY PLUNGER FORMING WITH SAID OTHER END OF SAID MASTER CYLINDER A SECONDARY CHAMBER CONNECTED TO THE OTHER VEHICLE WHEEL CYLINDERS, A FLUID PRESSURE MOTOR FOR ACTUATING SAID PRIMARY PLUNGER AND HAVING A VALVE MECHANISM FOR CONTROLLING THE CONNECTION OF SAID MOTOR TO A PRESSURE SOURCE TO OPERATE IT, SAID VALVE MECHANISM INCLUDING A MANUALLY OPERABLE MEMBER, REACTION MEANS FOR TRANSMITTING PRESSURES FROM SAID PRIMARY CHAMBER TO SAID MANUALLY OPERABLE MEMBER, SAID PRIMARY PLUNGER BEING MOVABLE TO ENGAGE AND OPERATE SAID SECONDARY PLUNGER UPON A FAILURE IN PRESSURE IN SAID PRIMARY CHAMBER, AND MEANS OPERATIVE UPON A FAILURE OF PRESSURE IN SAID PRIMARY CHAMBER FOR TRANSMITTING PRESSURE FROM SAID SECONDARY CHAMBER TO SAID REACTION MEANS TO OPPOSE MOVEMENT OF SAID MANUALLY OPERABLE MEMBER.