Master cylinder assembly

A master cylinder assembly for use with a control pedal of a motor vehicle, said assembly comprising:

• a cylinder housing defining a bore having a central axis;
• a piston mounted for reciprocal movement in said bore along said axis;
• an externally threaded tubular member mounted for reciprocal movement on said axis and adapted to pushingly engage an end face of said piston;
• a push rod adapted to be connected at one end thereof to the motor vehicle control pedal and extending through said tubular member for pushing engagement at its other end with said end face of said piston;
• a nut threadably passing said tubular member;
• and
• power means operative when actuated to rotate said nut and thereby move said tubular member along said axis.

A clutch actuator for use with a motor vehicle of the type including a manual gear box, a shift lever member for shifting the gears of the gear box, a clutch, and a clutch pedal member, said actuator including:

• a master cylinder assembly including a cylinder defining a bore open at its rear end and closed at its front end, a piston mounted for reciprocal movement in said bore and including a rear end and a front end coacting with said closed front end of said bore to define a pressure chamber therebetween, a discharge port proximate said closed end of said bore and communicating with said pressure chamber, and a push rod extending into said bore for direct pushing engagement at one end thereof with said rear end of said piston and adapted to be connected at its other end to the clutch pedal so that depression of the clutch pedal moves said piston in said bore to discharge pressure fluid from said pressure chamber through said discharge port;
• a slave cylinder adapted to be mounted proximate the clutch and including an inlet port receiving the pressure fluid from said pressure chamber;
• power means operative in response to movement of said clutch pedal member to apply a force to said rear end of said piston independently of any force applied thereto by said push rod;
• said power means comprising an electric motor and drive means drivingly interconnecting said electric motor in said piston;
• a nut driven by said electric motor;
• and
• a hollow screw driven by said nut, pushingly engaging an annular outer surface on said rear end of said piston, and centrally passing said push rod to allow said push rod to pushingly engage a central surface on said rear end of said piston.

A clutch actuator for use with a motor vehicle of the type including a manual gear box, a shift lever member for shifting the gears of the gear box, a clutch, and a clutch pedal member, said actuator including:

• a master cylinder assembly including a cylinder defining a bore open at its rear end and closed at its front end, a piston mounted for reciprocal movement in said bore and including a rear end and a front end coacting with said closed front end of said bore to define a pressure chamber therebetween, a discharge port proximate said closed end of said bore and communicating with said pressure chamber, and a push rod extending into said bore for direct pushing engagement at one end thereof with said rear end of said piston and adapted to be connected at its other end to the clutch pedal so that depression of the clutch pedal moves said piston in said bore to discharge pressure fluid from said pressure chamber through said discharge port;
• a slave cylinder adapted to be mounted proximate the clutch and including an inlet port receiving the pressure fluid from said pressure chamber;
• and
• power means operative in response to movement of said shift lever member to apply force to said rear end of said piston independent of any force applied thereto by said push rod.

A brake actuator for use with a motor vehicle of the type including a braking system including a brake pedal for operator actuation, said actuator including:

• a master cylinder assembly including a cylinder defining a bore open at its rear end and closed at its front end, a piston mounted for reciprocal movement in said bore and including a rear end and a front end coacting with said closed front end of said bore to define a pressure chamber therebetween, a discharge port proximate said closed end of said bore and communicating with said pressure chamber, and a push rod extending into said bore for direct pushing engagement at one end thereof with said rear end of said piston and adapted to be connected at its other end to the clutch pedal so that depression of the clutch pedal moves said piston in said bore to discharge pressure fluid from said pressure chamber through said discharge port;
• a slave cylinder adapted to be mounted proximate the braking assembly located at a wheel of the vehicle and including an inlet port receiving the pressure fluid from said pressure chamber;
• and
• power means operative in response to depression of said brake pedal to apply a force to said rear end of said piston independently of any force applied thereto by said push rod;
• said power means comprising an electric motor and drive means interconnecting said electric motor and said piston;
• said drive means comprising a nut driven by said electric motor and a hollow screw driven by said nut, pushingly engaging an annular outer surface on said rear end of said piston, and centrally passing said push rod to allow said push rod to pushingly engage the central surface on said rear end of said piston.