Abstract: A testing method includes the steps of: (1) providing a negative pressure generator; (2) generating a negative pressure in a fluid passageway and a chamber which are in fluid communication with a guiding section of a fluid reservoir wherein a second sensing element is affixed to a guiding section of the fluid reservoir; (3) transferring a fluid flow stream from the guiding section to the chamber via the fluid passageway and drawing a float having a first sensing element from an upper position to a lower position within the guiding section; (4) generating a signal via the first and second sensing elements as the float moves relative to the second sensing element within the guiding section; and (5) transmitting a signal to at least one of a control unit or a graphical user display.

Abstract: A fluid level detector assembly is used to determine the level of fluid in a tank. The assembly includes a float movably mounted within the tank which corresponds to the level of fluid within the tank. The fluid level detector assembly further includes a sensor assembly for detecting movement of the float, and a mechanism for causing movement of the float hydraulically.

Abstract: A brake system having a wheel brake and being operable under a non-failure normal braking mode and a manual push-through mode. The system includes a master cylinder operable by a brake pedal during the manual push-through mode to provide fluid flow at an output for actuating the wheel brake. A first source of pressurized fluid provides fluid pressure for actuating the wheel brake under the normal braking mode. A second source of pressurized fluid generates brake actuating pressure for actuating the wheel brake under the manual push-through mode.

Abstract: The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include an elastomeric tubular torque coupler connected to a ball screw/nut anti-rotation member; and a clamped connection at an inner race of a motor bearing for securing the rotor to the ball screw/nut component.

Abstract: An electrohydraulic vehicle braking system is provided, comprising an electrically controllable first hydraulic pressure generator and an electrically controllable second hydraulic pressure generator. The braking system further comprises a first valve device for each wheel brake, having at least one first valve, wherein in an electrically uncontrolled state the first valve device separates its associated wheel brake from an output of the first hydraulic pressure generator, and in an electrically controlled state connects it to the output of the first hydraulic pressure generator. In addition, a second valve device for each wheel brake is provided, having a second valve between an output of the second hydraulic pressure generator and its associated wheel brake, as well as a third valve between this wheel brake and a first hydraulic fluid reservoir. The first valve device and the second valve device are arranged in parallel to one another.

Abstract: The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include the plunger assembly engage at least one seal that defines a portion of a pressurized chamber. An end cap covers the projecting end of the cylinder and is secured to the housing to define a fluid passageway between the end of the cylinder and at least one fluid passageway provided in the housing block.

Abstract: A brake system has a wheel brake and is operable under a non-failure normal braking mode and a manual push-through mode. The system includes a master cylinder operable by a brake pedal during a manual push-through mode to provide fluid flow at an output for actuating the wheel brake. A first source of pressurized fluid provides fluid pressure for actuating the wheel brake under a normal braking mode. A secondary brake module includes a plunger assembly for generating brake actuating pressure for actuating the wheel brake under the manual push-through mode.

Abstract: A brake system having a wheel brake and being operable under a non-failure normal braking mode and a manual push-through mode. The system includes a master cylinder operable by a brake pedal during the manual push-through mode to provide fluid flow at an output for actuating the wheel brake. A first source of pressurized fluid provides fluid pressure for actuating the wheel brake under the normal braking mode. A second source of pressurized fluid generates brake actuating pressure for actuating the wheel brake under the manual push-through mode.

Abstract: The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include an elastomeric tubular torque coupler connected to a ball screw/nut anti-rotation member; and a clamped connection at an inner race of a motor bearing for securing the rotor to the ball screw/nut component.

Abstract: The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include a linear actuator rotationally supported on the housing by a bearing to actuate the plunger head connection to a ball screw.

Abstract: The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include, the cylinder projecting from one side of a housing with an end cap covering the projecting end of the cylinder and is secured to the housing block in a generally coaxial relationship with the cylinder. The cylinder and the end cap cooperate to define a fluid passageway between the end of the cylinder and at least one fluid passageway provided in the housing block. The plunger head may include a stop cushion assembly.

Abstract: A brake system includes first and second wheel brakes, a reservoir, and a brake pedal unit having a housing and a pair of output pistons slidably disposed in the housing. The output pistons generate brake actuating pressure during a manual push-through mode for actuating the first and second wheel brakes. The system further includes a plunger assembly having a housing having a motor driving an actuator, and a piston connected to the actuator. The piston pressurizes a chamber when the piston is moving in a first direction to provide fluid flow out of a first port and through a pair of parallel valves. The piston pressurizes a second chamber when the piston is moving in a second direction opposite the first direction to provide fluid flow out of a second port. The first and second ports are selectively in fluid communication with the wheel brakes.

Abstract: A master cylinder includes a housing and a first secondary piston disposed in the housing. The first secondary piston cooperates with the housing to define a first secondary chamber which changes volume as the first secondary piston moves in the housing. A second secondary piston is disposed in the housing and cooperates with the housing to define a second secondary chamber which changes volume as the second secondary piston moves in the housing. A stepped primary piston is disposed in the housing. The primary piston cooperates with the housing to define a primary chamber which changes volume as the primary piston moves in the housing. The primary piston defines an abutment surface which can be driven into abutment with the first secondary piston and the second secondary piston to move the first secondary piston and the second secondary piston. A primary piston spring maintains a restorative force on the primary piston when actuated.

Abstract: A vehicle braking system includes a slip control system operable in an electronic stability control (ESC) mode to automatically and selectively apply the brakes in an attempt to stabilize the vehicle when an instability condition has been sensed. The slip control system is further operable in an adaptive cruise control (ACC) mode to automatically apply the brakes to slow the vehicle in response to a control signal. The slip control system includes a variable speed motor drive piston pump for supplying pressurized fluid pressure to the brakes through a valve arrangement. In the ESC mode, the pump motor operates in an ESC speed range, and in the ACC mode, the pump motor operates in an ACC speed range lower than the ESC speed range. The slip control system further includes an attenuator connected to a pump outlet for dampening pump output pressure pulses prior to application to the brakes. The attenuator includes an elastomeric member located in an attenuator chamber of a housing.

Abstract: A vehicle brake system includes a brake pedal unit coupled to a vehicle brake pedal. The system includes an input piston connected to operate a pedal simulator during a normal braking mode, and coupled to actuate a pair of output pistons during a manual push through mode. The output pistons are operable to generate brake actuating pressure at first and second outputs of the brake pedal unit. A hydraulic pressure source supplies fluid at a controlled boost pressure. A hydraulic control unit is adapted to be hydraulically connected to the brake pedal unit and the hydraulic pressure source. The hydraulic control unit includes a slip control valve arrangement, and a switching base brake valve arrangement for switching the brake system between the normal braking mode wherein boost pressure from the pressure source is supplied to first and second vehicle brakes, and the manual push through mode wherein brake actuating pressure from the brake pedal unit is supplied to the first and second vehicle brakes.

Abstract: A vehicle braking system includes a slip control system operable in an electronic stability control (ESC) mode to automatically and selectively apply the brakes in an attempt to stabilize the vehicle when an instability condition has been sensed. The slip control system is further operable in an adaptive cruise control (ACC) mode to automatically apply the brakes to slow the vehicle in response to a control signal. The slip control system includes a variable speed motor drive piston pump for supplying pressurized fluid pressure to the brakes through a valve arrangement. In the ESC mode, the pump motor operates in an ESC speed range, and in the ACC mode, the pump motor operates in an ACC speed range lower than the ESC speed range. The slip control system further includes an attenuator connected to a pump outlet for dampening pump output pressure pulses prior to application to the brakes. The attenuator includes an elastomeric member located in an attenuator chamber of a housing.

Abstract: A vehicle brake system includes a brake pedal unit coupled to a vehicle brake pedal. The system includes an input piston connected to operate a pedal simulator during a normal braking mode, and coupled to actuate a pair of output pistons during a manual push through mode. The output pistons are operable to generate brake actuating pressure at first and second outputs of the brake pedal unit. A hydraulic pressure source supplies fluid at a controlled boost pressure. A hydraulic control unit is adapted to be hydraulically connected to the brake pedal unit and the hydraulic pressure source. The hydraulic control unit includes a slip control valve arrangement, and a switching base brake valve arrangement for switching the brake system between the normal braking mode wherein boost pressure from the pressure source is supplied to first and second vehicle brakes, and the manual push through mode wherein brake actuating pressure from the brake pedal unit is supplied to the first and second vehicle brakes.

Abstract: A system is disclosed for controlling the roll of a motor vehicle. The system comprises a selective lock connected between an unsprung portion of the vehicle and a sprung portion of the vehicle.

Abstract: A master cylinder includes a housing and a first secondary piston disposed in the housing. The first secondary piston cooperates with the housing to define a first secondary chamber which changes volume as the first secondary piston moves in the housing. A second secondary piston is disposed in the housing and cooperates with the housing to define a second secondary chamber which changes volume as the second secondary piston moves in the housing. A stepped primary piston is disposed in the housing. The primary piston cooperates with the housing to define a primary chamber which changes volume as the primary piston moves in the housing. The primary piston defines an abutment surface which can be driven into abutment with the first secondary piston and the second secondary piston to move the first secondary piston and the second secondary piston. A primary piston spring maintains a restorative force on the primary piston when actuated.

Abstract: A brake module provides a first circuit, a second circuit, and a third circuit of pressurized brake fluid. A first set and second set of brake actuators are operated by the application of pressurized brake fluid. A first and second fluid separator unit are integrated between the first and second circuit, and the first and third circuit, respectively, for substantially preventing any intermixing of pressurized brake fluid between the first, second, and third circuits. The first and second fluid separator units include a moveable pressure boundary which enables the second circuit and third circuit of pressurized brake fluid to selectively act upon the first set and second set of brake actuators in response to the first circuit of pressurized brake fluid acting upon the first and second fluid separator units. At least one proportional valve selectively controls the pressurized brake fluid of the first circuit for acting on the first and the second fluid separator units.