Abstract: A polygonal device for teaching students who prefer kinesthetic learning methods is presented in which the polygonal device can represent two-dimensional polygons of varying shapes and sizes. One or more of the sides, or legs, of the polygonal device are extendable, and the angles of the polygonal device may be manipulated to a desired angle. The devices presented include, but are not limited to, triangles, quadrilaterals, parallelograms, rectangles, squares, trapezoids, and kites. In each of these devices, the legs of the device are non-detachable, i.e. the device does not come apart during normal manipulation and operation.

Abstract: A polygonal device for teaching students who prefer kinesthetic learning methods is presented in which the polygonal device can represent two-dimensional polygons of varying shapes and sizes. One or more of the sides, or legs, of the polygonal device are extendable, and the angles of the polygonal device may be manipulated to a desired angle. The devices presented include, but are not limited to, triangles, quadrilaterals, parallelograms, rectangles, squares, trapezoids, and kites. In each of these devices, the legs of the device are non-detachable, i.e. the device does not come apart during normal manipulation and operation.

Abstract: A disc brake caliper assembly has a housing with a bore. A piston in the bore is movable between applied, retracted and knock-back positions. The piston is activatable by hydraulic pressure to move from the retracted position to the applied position; and a retracting seal is effective in the absence of the hydraulic pressure to move the piston from the applied position to the retracted position. A linkage adjacent the piston carries a stop; and an actuator is responsive to an end of brake activation signal to cause the linkage to engage the stop with the piston when the piston is retracted from its applied position to its retracted position so as to prevent the piston from moving from the retracted position to the knock-back position. The actuator is preferably a comparatively weak electric motor that stalls as the stop engages the piston; and the stall is sensed to end motor activation. The end of brake activation signal is preferably provided by a brake position or pressure sensor.

Abstract: A disc brake caliper assembly is provided that includes a housing having a bore. A piston is arranged within the bore and is movable between normal retracted and knock-back positions. A linkage is adjacent to the piston and is movable between first and second positions with a clearance between the piston and the linkage in the first position. The clearance undesirably permits the piston to move to the knock-back position during severe operating conditions. An actuator, which also may be used as part an electric parking brake, moves the linkage from the first position to the second position to eliminate the clearance when the linkage is moved from the first position to the second position where the linkage abuts the piston. The linkage is connected to the caliper housing by a support. The linkage prevents the piston from moving from the normal retracted position to the knock-back position.

Abstract: A disc brake caliper assembly has a housing with a bore. A piston in the bore is movable between applied, retracted and knock-back positions. The piston is activatable by hydraulic pressure to move from the retracted position to the applied position; and a retracting seal is effective in the absence of the hydraulic pressure to move the piston from the applied position to the retracted position. A linkage adjacent the piston carries a stop; and an actuator is responsive to an end of brake activation signal to cause the linkage to engage the stop with the piston when the piston is retracted from its applied position to its retracted position so as to prevent the piston from moving from the retracted position to the knock-back position. The actuator is preferably a comparatively weak electric motor that stalls as the stop engages the piston; and the stall is sensed to end motor activation. The end of brake activation signal is preferably provided by a brake position or pressure sensor.

Abstract: A brake by wire system provides the capability of both travel and force sensors on a brake apply input member such as a brake pedal and also provides redundancy in sensors by providing the signal from a sensor responsive to travel or position of the brake pedal to a first controller and the signal from a sensor responsive to force applied to the brake pedal to a second controller. The first and second controllers are connected by a bi-directional communication link whereby each controller may communicate its received one of the sensor signals to the other controller. In at least one of the controllers, linearized versions of the signals are combined for the generation of first and second brake apply command signals for communication to brake apply units. If either controller does not receive one of the sensor signals from the other, it nevertheless generates its brake apply command signal on the basis of the sensor signal provided directly to it from the sensor.

Abstract: Improved control for a hydraulic system useful in automotive braking applications, particularly in dry interface automotive braking applications, includes the use of a valve for holding pressure in a hydraulic system constant while relieving the pressure load on the pressure source. Preferably, the valve is a normally-open solenoid valve that is closed and opened in response to a desired pressure being sensed at a pressure actuated mechanism, such as a brake caliper. The use of the improved control for a hydraulic system improves brake response times during ABS applications, and increases the energy efficiency and life expectancy of the pressure providing motor.

Abstract: A brake by wire system provides the capability of both travel and force sensors on a brake apply input member such as a brake pedal and also provides redundancy in sensors by providing the signal from a sensor responsive to travel or position of the brake pedal to a first controller and the signal from a sensor responsive to force applied to the brake pedal to a second controller. The first and second controllers are connected by a bi-directional communication link whereby each controller may communicate its received one of the sensor signals to the other controller. In at least one of the controllers, linearized versions of the signals are combined for the generation of first and second brake apply command signals for communication to brake apply units. If either controller does not receive one of the sensor signals from the other, it nevertheless generates its brake apply command signal on the basis of the sensor signal provided directly to it from the sensor.

Abstract: An electro-hydraulic actuator for a motor vehicle brake-by-wire brake system including a housing, a piston bore in the housing, a T-shaped piston in the piston bore, and an electric motor connected to the piston through a speed reducer. The T-shaped piston includes a disc-shaped head in the piston bore and a tubular stem perpendicular slidable in and out of the piston bore through a sealed guide in the bottom of the piston bore. The top side of the piston head opposite the stem constitutes a large effective area of the piston for rapidly expelling a relatively large volume of fluid from the piston bore in a low pressure interval of operation the actuator. When the fluid pressure in the piston bore exceeds a transition pressure, a transition valve opens a bypass passage to the piston bore behind the piston head so that the same fluid pressure reacts against the bottom side of the piston head around the stem.

Abstract: A brake pedal for a motor vehicle brake-by-wire brake system including a pedal lever resiliently flexible in beam bending, a foot pad on the pedal lever, and a mounting for the pedal lever on a body of the motor vehicle which constitutes the pedal lever a variable stiffness cantilever spring. The mounting for the pedal lever includes a socket for an inboard end of the pedal lever, a stationary reaction surface on the body of the motor vehicle, and a pedal lever reaction surface on the pedal lever which faces and diverges from the stationary reaction surface in a release position of the pedal lever. The stationary reaction surface and the pedal lever reaction surface become progressively engaged concurrent with resilient flexure of the pedal lever in cantilever spring bending to vary the stiffness of the cantilever spring.

Abstract: A brake apply system includes a pressure charging module having a bore carrying a pumping piston that has a base piston surface and an augmentation piston surface. The pressure charging piston separates the bore into an input chamber adjacent the base piston surface and an output chamber adjacent the augmentation piston surface. A suspension damper is hydraulically connected to the input chamber of the pressure charging module, preferably through a continuously open fluid communication circuit. A wheel brake is hydraulically connected to the accumulator output chamber through a selectively open fluid communication circuit.

Abstract: A brake apply system includes a modulator that has a first bore carrying a power driven dual-effect piston. The piston has a base piston surface and an augmentation piston surface. A wheel brake is hydraulically connected to the modulator through an open fluid communication route that is provided between the wheel brake and the base piston surface. A selectively open fluid communication route is provided between the wheel brake and the augmentation piston surface with a check valve mechanism positioned in the selectively open fluid communication route. An augmentation chamber is defined adjacent the augmentation surface of the dual-effect piston. The modulator includes a second bore carrying a valve mechanism that provides an open flow path between the augmentation chamber and a reservoir when pressure at the wheel brake is relatively high and that significantly restricts the flow path when the wheel brake pressure is relatively low.

Abstract: A brake system includes a pedal feel emulator and a master cylinder with a damping mechanism having a damping piston. When the emulator piston is moved from the at-rest position, fluid is displaced from the emulator through a compensation port and through a flow restrictive orifice in the damping piston to the reservoir. Flow rate of the fluid is dependent on the apply rate of the brake pedal. When the brake pedal is applied relatively slowly, sufficient flow volume will occur through the flow restrictive orifice and the damping piston will remain unmoved. As apply rates increase, a sufficient pressure differential will eventually be established across the damping piston to cause it to move. Damping piston movement compensates for rapid fluid displacement out of the variable chamber and enables a desirable pedal feel characteristic where pedal force increases relatively slowly as pedal velocity increases relatively rapidly.

Abstract: A power booster is operable at relatively low apply rates and at relatively high apply rates and includes an input assembly that has a movable input rod and a primary reaction piston having a first reaction area. An output support body is responsive to movement of the input rod, with a resilient reaction disc engaging the output support body. A secondary reaction body has a second reaction area and is engageable with the reaction disc and transfers loads between the reaction disc and the input assembly at relatively low apply rates. The amount of the load transferred is a function of both the first reaction area and the second reaction area at the relatively low apply rates resulting in a first reaction ratio. The primary reaction piston is engageable with the reaction disc and transfers loads between the output support body and the input assembly during relatively high apply rates.

Abstract: A pressurized brake bleed system includes a rigid container, a flexible container containing brake fluid disposed within the rigid container, a hose having one end connected to the flexible container and another end for connection to a fluid reservoir of a brake system and a structure to apply a force to pressurize the flexible container to bleed the brake fluid from the flexible container through the hose to the fluid reservoir.

Abstract: An electro-hydraulic brake apply system includes an emulator that effects pedal feel simulation by allowing compliance at a selective variable rate. This provides a vehicle driver with the preferred pedal travel and feedback characteristics of a conventional master cylinder/power booster apply system. As a secondary function, the emulator is utilized to latch the modulator. This locks the modulator apply piston in place when electrical power is removed from the drive motor. Further, the emulator operates to hydraulically isolate the master cylinder from the wheel brakes during normal system operation.

Abstract: A chassis system control method comprising the steps of measuring rotational speed of a plurality of vehicle wheels; estimating, responsive to each wheel rotational velocity, a relative velocity between the wheel and a corresponding corner of a vehicle body; determining a chassis system control command responsive to the estimations; and applying the chassis system control command to control the chassis system responsive to the estimations, wherein need for body to wheel relative position and/or relative velocity sensors is eliminated.

Abstract: A vehicle braking system that primarily operates as a pure brake-by-wire system, with optional hydraulic actuation. The system includes a set of four electrically actuated drum brakes. At least two of the wheel brakes include hydraulic actuators that operate to apply the wheel brakes independent of electric control. Each of the wheel brakes is normally operated in response to a control signal generated by the vehicle's brake processor. As such, a primary brake-by-wire system is provided at all four vehicle wheels. The rear brakes are proportioned to the front brakes electrically, according to design criteria.

Abstract: A master cylinder and emulator includes a primary piston and a secondary piston which are movable to provide fluid pressure to effect wheel braking in a vehicle. In addition, the master cylinder includes an emulator assembly which supplies conventional pedal feel and travel characteristics when the primary and secondary pistons are substantially immovable due to isolation of the master cylinder from the wheel brakes. The emulator assembly includes a piston that is movable against a selected amount of fluid pressure and spring force while the primary piston remains stationary. The fluid force is supplied by controlling the flow of fluid from behind the piston through a flow restrictive orifice to a conventional fluid reservoir on the master cylinder assembly. The master cylinder and emulator assembly is operable to provide brake actuation assist to an electric or electro-hydraulically controlled braking system.

Abstract: A rotary actuated braking system includes a motor driven shaft that operates two pairs of piston pumps and an allocation valve which, in combination with a single solenoid valve, effects ABS operation of the braking system. A combination of pressure operated control valves and pressure operated release valves for each control wheel brake respond to operation of the rotary actuator and solenoid valve to effect ABS pressure release and reapply from the corresponding wheel brake. A power boosted master cylinder provides base brake operation independent of the rotary actuator effected ABS operation.