Abstract: A pump assembly with a combination reciprocating high-pressure seal and fluid inlet check valve for use within brake systems. The pump assembly comprises a housing having a bore formed therethrough and a piston disposed within the bore for reciprocal movement therein. An annular seal is disposed around the piston for reciprocal movement thereon. The annular seal cooperates with the piston and/or the housing to form at least one longitudinally extending passageway. The passageway, the piston, the annular seal, and the housing cooperating to form a check valve assembly. The annular seal is moveable to a first position relative to the piston in which the check valve assembly is in a flow-through position to fill a pump chamber with fluid from an inlet chamber during a fluid inlet stroke. The annular seal is moveable to a second position relative to the piston in which the check valve assembly is closed.

Abstract: A hydraulic braking system including first and second braking circuits. The first and second braking circuits each include a wheel brake, a pressurized fluid source, and a hydraulic conduit connecting the wheel brake to the fluid source. Each of the hydraulic conduits includes a control valve that operates to selectively prevent fluid flow from the pressurized fluid source to the wheel brake. A connecting conduit connects the first and second braking circuits. A floating piston is disposed within the connecting conduit and is adapted to be displaced by the pressurized fluid provided by the pressurized fluid source in the first braking circuit when the control valve of the first braking circuit is closed. The displacement of the piston generates an additional volume of pressurized fluid in the hydraulic conduit of the second braking circuit that effectively augments the pressurized fluid provided by the second pressurized fluid source.

Abstract: A control valve for controlling fluid flow in a hydraulic control unit of a vehicular brake system includes a valve seat. A sleeve is mounted on the valve seat. An armature core is slidably received in the sleeve. The sleeve includes a first ferromagnetic portion adjacent the valve seat, a second ferromagnetic portion, and an annular region defining an area of increased magnetic reluctance. A part of the first portion of the sleeve defines a radial magnetic pole for the generally radial flow of magnetic flux from the armature to the sleeve. A portion of the valve seat adjacent the armature defines an axial magnetic pole for the generally axial flow of magnetic flux from the armature to the valve seat. Together, the generally radial flow of flux and the generally axial flow of flux generate a force urging the armature from an open position toward a closed position when the coil is energized.

Abstract: A control valve for controlling fluid flow in a hydraulic control unit of a vehicular brake system includes a valve seat. A sleeve is mounted on the valve seat. An armature core is slidably received in the sleeve. The sleeve includes a first ferromagnetic portion adjacent the valve seat, a second ferromagnetic portion, and an annular region defining an area of increased magnetic reluctance. A part of the first portion of the sleeve defines a radial magnetic pole for the generally radial flow of magnetic flux from the armature to the sleeve. A portion of the valve seat adjacent the armature defines an axial magnetic pole for the generally axial flow of magnetic flux from the armature to the valve seat. Together, the generally radial flow of flux and the generally axial flow of flux generate a force urging the armature from an open position toward a closed position when the coil is energized.

Abstract: An electro-hydraulic control unit includes a valve body having a recess formed in a surface thereof and a circumferential wall which extends around the recess. The wall includes at least one widened portion. An electronic control Unit is mounted over the recess. The electronic control unit carries a circuit substrate which extends over the widened portion of the valve body wall such that widened portion of the valve body wall forms a heat for an electronic component carried by the circuit substrate. Additionally, components mounted on upon the circuit substrate, including a motor connector extending into the recess. A pump motor is mounted upon the valve body surface opposite from the electronic control unit. An electrical connector extends from the motor through a bore formed in the valve body and connects to the motor connector mounted upon the circuit substrate.

Abstract: An electronically controlled vehicular hydraulic brake system provides anti-lock braking, traction control, and vehicle stability control. The system includes a hydraulic control unit (HCU) containing control valves and other components in fluid communication with wheel brakes. Low temperatures cause the viscosity of hydraulic fluid to increase. Performance of the braking system can be improved at low temperatures according to methods of this invention. A first preferred method of improving braking performance is to increase the brake fluid temperature inside the HCU. Several examples of methods to increase fluid temperature inside the HCU are presented. A second preferred method of improving braking performance is to preload the wheel brakes with a pressure that does not adversely affect normal driving. Several examples of methods to preload the wheel brakes are presented.

Abstract: A vehicle brake system including a wheel brake and a master cylinder operable to provide pressurized fluid to the wheel brake. The master cylinder includes a housing having a bore formed therein, and further including a piston slidably disposed in the bore. The brake system further includes a fluid reservoir in selective fluid communication with the bore of the master cylinder. The brake system also includes an isolation valve movable between an open position, wherein fluid is permitted to flow between the master cylinder and the wheel brake, and a closed position, wherein fluid is restricted from flowing between the master cylinder and the wheel brake. The brake system further includes a dump valve movable between a closed position, wherein fluid is prevented from flowing between the wheel brake and the reservoir, and an open position, wherein fluid is permitted to flow between the wheel brake and the reservoir.

Abstract: A fabricated master cylinder having a reservoir part and in interlocked cylinder part defining a cylinder bore and which a slidable piston is supported. The reservoir part that extends into the cylinder bore defines a shoulder that cooperates with a recuperation valve for forming an actuating stop for holding the makeup fluid recuperation valve in an opened position when the piston is at its at rest position.