Abstract: A vehicle braking system such as an anti-lock brake system and/or a traction control utilizes a separate solenoid-actuated, two position, three-way valve in each controlled channel of the brake system for controlling the application of pressure to the respective wheel brake circuit. The valve includes a first port connected to the controlled wheel brake(s), a second port connected to an outlet of a hydraulic pump, and a third port connected to the inlet of the hydraulic pump. The valve is only moveable between a first position wherein the outlet of the pump is connected to the wheel brake to increase pressure to the wheel brake, and a second position wherein the wheel brake is connected to the inlet of the pump to decrease pressure to the wheel brake. An electronic control is provided for operating the valve to control the application of pressure to the selected wheel brakes.

Abstract: A control valve for an anti-lock brake system includes a one-piece valve body having an inlet opening in one end and an outlet opening in an opposite end. The valve body is provided with four other openings extending into the body and defining separate associated chambers for respectively receiving an isolation valve assembly, a pressure differential switch assembly, a dump valve assembly and an accumulator assembly. The inlet, outlet, and the four internal chambers are connected by appropriate internal passageways. The control valve is used to selectively hold, dump, or reapply brake fluid pressure to selected wheel brakes to prevent lock-up of the associated wheels.

Abstract: The present invention concerns a vehicle anti-lock brake control system which does not require the use of an auxiliary hydraulic pump and, in the preferred embodiment, is adapted to control only the rear brakes of a four-wheel vehicle. The control system includes a normally open solenoid actuated isolation valve connected between the master cylinder and the rear wheel brakes, and a normally closed solenoid actuated dump valve connected between the rear wheel brakes and a fluid accumulator. A computer control is connected to monitor the rear wheel speed and deceleration and, during breaking of the vehicle, functions to control the application of hydraulic pressure to the rear brakes via the isolation and dump valves in order to prevent lock-up of the brakes. In the event excessive rear wheel deceleration is detected during a vehicle stop, the computer control closes the isolation valve to hold pressure to the rear brakes at a relatively constant level.

Abstract: The present invention relates to a self-contained electric brake controller for energizing electrically operated brakes in a towed vehicle in response to a demand by a driver in a towing vehicle. The controller includes a unique deceleration sensing unit for generating a signal proportional to the magnitude of deceleration of the towing vehicle. The deceleration sensing unit includes an outer housing adapted to be secured relative to the towing vehicle, and a pendulum mounted on an axis for pivotal movement relative to the housing. The pendulum is movable in one direction from a resting position to a predetermined extended position when the vehicle is subjected to a predetermined magnitude of deceleration. The pendulum includes a magnet spaced from the pivot axis of the pendulum.

Abstract: An electric brake control circuit is responsive to an activation signal and a vehicle deceleration signal for generating a brake control signal representing a predetermined amount of braking. A comparator compares the voltage level of the brake control signal with the voltage level of a sawtooth waveform to produce a pluse width modulated signal having a duty cycle corresponding to the predetermined amount of braking. This pulse width modulated signal is supplied to an output driver for generating a brake driving signal to energize the brakes. The activation signal is generated at the voltage level of the vehicle power supply when the driver actuates the vehicle stop light switch. The circuit is responsive to the activation signal for disabling the output driver when the voltage level of the activation signal is below a predetermined level. The circuit also senses the current load on the brake driving signal to protect the output driver in the event of a full or partial short circuit condition.

Abstract: A method and apparatus for verifying proper operation of a vehicle anti-lock braking system includes pressure measuring devices which are releasably attached to an exterior surface portion of the flexible wheel brake hoses. Each measuring device senses changes in the external diameter of the associated hose, which changes are representative of fluid pressure changes within the hose. The valving in the braking system is tested by applying fluid pressure to the system, operating the associated valves in a predetermined sequence, and monitoring the pressure changes in the associated wheel brake hoses to determine whether the valving is operating properly.

Abstract: In accordance with the present invention, a normally open isolation valve is connected between a master cylinder and the selected wheel brakes, and a normally closed dump valve is connected between the selected wheel brakes and a fluid accumulator. A computer control module is connected to operate the isolation valve and the dump valve. In operation, when a slip condition of the controlled wheels is detected, the computer control module closes the isolation valve to hold fluid pressure to the controlled brakes at a relatively constant level. If the deceleration of the controlled wheels exceeds a predetermined amount, the computer control module will selectively open the dump valve to enable fluid to flow into the accumulator, thereby reducing the deceleration of the associated wheels.

Abstract: The present invention concerns a control valve for use in a vehicle anit-lock braking systm adapted to control the application of pressurized brake fluid to at least one selected vehicle brake. The valve includes an outer housing having an inlet coupled to receive pressurized brake fluid from the vehicle master cylinder and an outlet coupled to supply pressurized brake fluid to the selected vehicle brakes. A passageway is formed in the housing for connecting the inlet to the outlet. A normally open isolation valve is located in the passageway and is utilized to control the flow of fluid through the passageway between the inlet and the outlet. When an incipient wheel lock condition is detected, the isolation valve can be closed to prevent a further increase in pressure to the controlled brakes and to hold the pressure supplied to the controlled brakes at a relatively constant level.

Abstract: The present invention relates to a solenoid having a pole and armature construction wherein, when a predetermined constant current is applied to the solenoid winding, the magnetic force attracting the armature toward the pole decreases as the armature is moved in one direction relative to the pole and, the distance the armature is moved is substantially proportional to the current applied to the winding. These operating characteristics are achieved by a solenoid having a field member provided with a pole portion on one end thereof, and having an armature connected to the opposite end for movement relative to the pole portion. The armature is provided with an edge portion which is spaced from the pole portion to define an air gap therebetween. The pole portion produces a magnetic field which exerts a magnetic force on the armature edge portion in one direction relative to the pole portion.

Abstract: The present invention relates to a position sensor which can be utilized as a height sensor in an automatic vehicle suspension system. The sensor comprises a telescoping assembly including an elongate shaft having one end which is axially slidable within an outer housing. The telescoping assembly is connected between sprung and unsprung vehicle frame members. The outer ends of the shaft and the housing are each provided with a unique bifurcated socket unit and an associated retaining clip for attachment to a ball element connection point on the associated vehicle frame member. A pair of magnets are carried by the shaft and are adapted to generate a first magnetic field having one polarity and extending axially along a first portion of the shaft and a second magnetic field having an opposite polarity and extending axially along a second portion of the shaft.

Abstract: The present invention relates to a lever assembly which is coupled by a cable to operate a remote mechanism, such as a vehicle parking brake. The lever assembly comprises a lever pivotally mounted to a support member. A locking pawl pivotally mounted to the lever is adapted to engage one of a plurality of ratchet teeth on the support member for maintaining the lever in a selected pivoted position relative to the support member. The one end of the cable is coupled to the handle such that pivoting of the lever results in movement of the cable and operation of the remote mechanism. In accordance with the present invention, an adjusting device is provided for maintaining the cable within a predetermined tension range when the lever is in the non-operating position.

Abstract: An electronic control for electrically operated brakes utilizing solid state electronic components to control the braking mechanism in a towed vehicle. A transducer develops a control signal corresponding to the braking effort desired, and may be actuated by the hydraulic brake system of the towing vehicle or, alternately, may be actuated from the brake foot pedal itself or from a manual control. Power is applied to the brakes as a pulsating voltage, the pulse width of which is varied in response to the control signal. The pulse width is decreased with increasing currents to limit the power in the circuit when a short occurs in the towed vehicle brake circuit. The electronic control also may be used in other applications.