Abstract: The reliability of a pressure sensor is improved either by utilization of redundant components. A pair of pressure sensors are mounted upon a single pressure sensor diaphragm. Each of the pressure sensors is connected to one of a pair of signal conditioning circuits. The gain of one of the signal conditioning circuits is a fraction of the gain of the other signal conditioning circuit. The outputs of each of the signal conditioning circuits are compared to a corresponding threshold. If both of the output signals exceed the corresponding threshold, it is determined that a malfunction of the pressure sensor has occured.

Abstract: This invention relates to a vehicle drum brake assembly adapted to selectively frictionally engage a brake drum. The drum brake assembly includes a backing plate supported relative to a vehicle component and having at least three openings formed therethrough, at least one brake shoe supported on the backing plate for selective movement into frictional engagement with the brake drum, and a brake mechanism for selectively moving the brake shoe into frictional engagement with the brake drum. The drum brake assembly includes a pair of fasteners extending through two of the three openings provided in the backing plate to secure the backing plate to a fixed, non-rotatable component of the vehicle.

Abstract: A balanced resonant micro electromechanical system angular rate sensor includes a feedback control loop that generates a null signal to rebalance the sense element to cancel any a Coriolis force induced displacement of the proof mass. The null signal is proportional to the Coriolis force and is used as the sensor output signal. A test signal is injected into the null signal feedback control loop. The resulting sensor output signal is a function of the test signal. If there is no change in the output signal following the injection of the test signal or if the output signal resulting from the test signal exceeds a predetermined threshold, the sensor is defective. Because the test signal is used to cancel the proof mass displacement, the test verifies operation of the sensor element.

Abstract: The present invention determines a longitudinal wheel speed of an individual wheel from an angular rate signal from a wheel rotation sensor. Vehicle suspension information or operating characteristics are input to a suspension system mathematical model to determine instantaneous rolling radius, taking into account changes in tire rolling radius resulting from vertical motion of the road surface. Improved accuracy of wheel speed permits less severe filtering of wheel speeds in detecting wheel slip and/or modified speed and acceleration thresholds in slip control.

Abstract: A piston pump comprises cylinder attached within a cavity of a pump housing. An outlet check valve seat is defined about an outlet of the cylinder. A piston is slidably received in a bore of the cylinder and has a first passageway formed therein. A cylinder head encloses the outlet of the cylinder and defines a second passageway therein. The first passageway has an inlet in fluid communication with the cavity of the pump housing, and an outlet in fluid communication with a pumping chamber defined in the pump housing. A first spring retains the piston to the cylinder. A first check valve member is a ball retained near a valve seat formed in the first passageway of the piston by a disk spring, and allows fluid to flow only from the inlet to the outlet of the piston.

Abstract: The present invention provides a proportional microvalve having a first, second and third layer, and having high aspect ratio geometries. The first layer defines a cavity with inlet and outlet ports. The second layer, doped to have a low resistivity and bonded between the first and third layers, defines a cavity having a flow area to permit fluid flow between the inlet and outlet ports. The second layer further defines an actuatable displaceable member, and one or more thermal actuators for actuating the displaceable member to a position between and including an open and a closed position to permit or occlude fluid flow. The third layer provides one wall of the cavity and provides electrical contacts for electrically heating the thermally expandable actuators. The thermal actuators and the displaceable member have high aspect ratios and are formed by deep reactive ion etching such that they are displaceable in the plane of the second layer while being very stiff out of the plane.

Abstract: A microvalve device for controlling fluid flow in a fluid circuit. The microvalve device comprises a body having a cavity formed therein. An electronically controlled automatic transmission, comprising of an input shaft; an output shaft; a plurality of gears providing driving connection between the input shaft and the output shaft; one of a hydraulically operated brake band and a hydraulically operated clutch which is operable to effect a change in the gear reduction provided by the gears between the input shaft and the output shaft; a source of pressurized hydraulic fluid; and a microvalve device selectively operable to control passage of pressurized hydraulic fluid from the source to the one of a hydraulically operated brake band and a hydraulically operated clutch to operate the one of a hydraulically operated brake band and a hydraulically operated clutch.

Abstract: A pressure sensor is mounted integrally in a hydraulic valve body. The sensor has a base which extends into a bore formed in the valve body. The valve body bore is in communication with a pressurized hydraulic fluid. A first circumferential groove formed in the sensor base carries an O-ring which forms a seal between the sensor and the wall of the valve body bore. A second circumferential groove formed in the sensor base carries a spring ring which extends into a corresponding groove formed in the wall of the valve body groove. The spring ring cooperates with the sensor base and valve body bore grooves to retain the sensor in the valve body bore.

Abstract: This invention relates to a drum-in-hat disc brake assembly. According to one embodiment of the invention, only four fasteners extend through the associated apertures of the backing plate, the drum-in-hat adapter, the axle flange and the caliper bracket for securing the caliper bracket, drum-in-hat adapter and the backing plate to the axle flange. Two of the four fasteners extend through the two apertures of the caliper bracket and at least partially into two of the four apertures of the axle flange to thereby secure the caliper bracket to the axle flange. The other two of the four fasteners extend through the two smaller apertures of the backing plate and the drum-in-hat adapter and at least partially into the remaining two apertures of the axle flange to thereby secure the backing plate and the drum-in-hat adapter to the axle flange.

Abstract: This invention relates to a disc brake assembly having a slide pin bushing protection shield attached thereto using the existing slide pin. The disc brake assembly includes an anchor plate secured to a stationary component of the vehicle and a caliper secured to the anchor plate for sliding movement therewith by a pair of slide pin bushing assemblies. Each of the slide pin bushing assemblies includes a slide pin, a sleeve, and a flexible bushing. The slide pin bushing protection shield includes at least a first side, a second side, a third side and a pair of mounting tabs. Once the slide pin bushing protection shield it is attached to the brake assembly, the shield effectively surrounds a substantial portion of the exposed portions of the flexible bushing to protect the same from possible damage due to rocks, dirt, and other road debris.

Abstract: This invention relates to an improved pad retraction spring (30) adapted for use in a disc brake assembly. The disc brake assembly includes an anchor bracket (12) adapted to be secured to a vehicle component, a brake caliper (108) adapted to be secured to the anchor bracket, a pair of brake shoes (18, 20) carried by the disc brake assembly and adapted to be disposed on opposite axial sides of an associated brake rotor (106), and an actuation device for selectively moving the brake shoes into frictional engagement with the rotor. The anchor bracket includes a pair of outwardly extending arms (14, 16) and at least one of the arms has an opening (60) formed therethrough. The pad retraction spring is carried by the disc brake assembly and is operative to move the brake shoes from engagement with the rotor when the brake shoes are in a non-braking position. The pad retraction spring includes a central mounting portion (32) and a pair of outermost spring arms (38, 38′).

Abstract: The invention relates to a composite brake caliper and method for producing the same. The method for producing the composite brake caliper comprises the steps of: (a) providing a molding apparatus having at least a pair of mold sections, at least one of the pair of mold sections including at least one projection extending from a surface thereof; (b) providing at least one reinforced preform formed from at least a first material, the preform having at least one opening formed at least partially therein; (d) positioning the preform in the molding apparatus with the projection of the mold section extending into the opening of the preform so as to orient the preform in a predetermined position within the molding apparatus; and (e) casting a caliper body formed from a second material in situ therewith to produce the composite brake caliper.

Abstract: An inertial sensor includes a plurality of sense elements disposed upon a silicon wafer. Each of the sense elements senses a different inertia range. The sense elements are electrically connected to a common signal conditioning circuit that generates an output signal for each of the sense elements. The signal conditioning circuit has an output that is electrically connected to at least one control system and provides output signals in different ranges to the control system.

Abstract: A microvalve device includes a first plate, a second plate and a third plate. The second plate is connected between the first plate and the third plate. The second plate contains a stationary element and a moveable plate valve slider element. The slider element variably restricts the flow of a fluid through the microvalve device. The second plate defines a first supply port, an output conduit, and a return port. In a pressure increase position, the slider element allows the fluid to flow from the first supply port to the output conduit. In a pressure hold position, the slider element isolates the output conduit from both the first supply port and the return port. The pressure decrease position allows fluid to flow from the output conduit to the return port. Pressure from the output conduit acts against a first axial end face of the slider element.

Abstract: A method of boundary self-adaptation for proportional poppet valve pressure control comprises implementing an estimator to estimate a boundary deviation of the valve. Then, a pressure command signal is detected. Next, a pressure command derivative over time is obtained. Then, determining which closing boundary should be updated is decided based on the sign of the pressure command derivative. Next, a pressure error is obtained by subtracting an actual wheel brake pressure from its pressure command. Then a modified pressure error is calculated. Next, a pressure command signal is evaluated to determine whether a braking maneuver is gentle. Next, the modified pressure error is implemented in the estimation. Finally, a boundary table is updated using the resultant boundary deviation estimate.

Abstract: This invention relates to a brake shoe mounting system for a vehicle brake assembly. The vehicle brake assembly brake shoe mounting system includes a brake mounting member and a pair of brake shoes slidably supported relative to the brake mounting member. The brake member is adapted to be secured to a fixed, non-rotatable component of the vehicle and includes an abutment having a pair of opposed slots formed therein. Each brake shoe includes a first end, an opposite second end, a web portion, a rim portion secured to an outer surface of the web portion, a friction pad secured to an outer surface of the rim portion, and only two shoe slides provided on at least one side of the rim portion. One of the two shoe slides is provided near the first end of the brake shoe and the other of the two shoe slides is provided generally intermediate the first and second ends of the brake shoe. In accordance with this invention, the second end of the brake shoe defines a shoe abutment end.

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 armature core has a passage extending between first and second planar end surfaces of the armature core. An armature body is formed from a moldable material onto the armature core. The armature body has a central section received in the passage of the armature core, a first end section extending from the first end surface of the armature core, and a second end section extending from the second end surface of the armature core. This control valve is particularly adapted to be mounted in a bore of a housing of a hydraulic control unit of an electronically controlled vehicular brake system.

Abstract: A microvalve device for controlling fluid flow in a fluid circuit. The microvalve device comprises a body having a cavity formed therein. A pilot valve supported by the body is movably disposed in the cavity for opening and closing pilot ports formed in the body. A pilot operated microvalve is positioned by the pressure of the fluid controlled by the pilot valve.

Abstract: A hydraulic control unit (HCU) for a vehicle brake system having an HCU body and an accumulator mounted in the HCU body. A grommet is provided for mounting the HCU body to a vehicle body and resiliently separating the HCU body from the vehicle body. The grommet defines a vent path for the accumulator and includes a hollow generally cylindrical shaft. The shaft has a closed end and an open end, and the closed end has an opening therethrough. An enlarged annular head is formed on the open end of the shaft and has an inner surface defining an axial bore therethrough. The axial bore is in fluid communication with the hollow shaft, the annular head further has a crown cut geometry providing radially extending grooves within an axial face of the annular head, the radially extending grooves being in fluid communication with the axial bore of the annular head.

Abstract: A shield and seal assembly adapted for use in a wheel end assembly of a vehicle includes a generally non-flexible shield and a generally flexible seal integrally molded in situ with the shield. The shield includes a first leg, a second leg, a third leg, a fourth leg, and a fifth leg. The first leg extends in a generally radially outwardly extending direction, the second leg extends in a generally radial direction, the third leg extends in a generally axial direction, the fourth leg extends in a generally axial direction, and the fifth leg extends in a generally radial direction. The seal includes a first end portion, a second end portion, and an intermediate body connecting the first end portion and the second end portion together. The first end portion defines a grease lip of the seal, and the second end portion defines a first dust lip of the seal.