Kelsey-hayes Company

John S Frait

Michael D Warner

David T Ayers, Jr

Leonard T Tribe

Clark E Lowman

George W Morris, Iii

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. A detector such as a Hall Effect device is carried by the housing and is responsive to the magnetic field produced by the pendulum magnet for generating a position signal representing the predetermined extended position of the pendulum. This position signal corresponds to the predetermined magnitude of deceleration of the vehicle. The deceleration sensing unit includes a second magnet carried by the housing and spaced from the pendulum for producing a magnetic field which, as the pendulum swings to its extended position, opposes the magnetic field of the pendulum magnet to produce a restoring force to resist further forward movement of the pendulum. The deceleration sensing unit also includes a damping element constructed of a ferromagnetic material spaced from the pendulum magnet for damping undesirable movement of the pendulum. Also, the circuit responsive to the deceleration signal includes several unique features.

Deceleration sensor for an electric brake controller

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. As the sensed current load progressively exceeds a predetermined level, the circuit progressively increases the average voltage level of the sawtooth waveform, thus causing the comparator to reduce the duty cycle of the pulse width modulated signal.

Electric brake controller

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. A pair of axially spaced apart Hall effect switches are carried by the housing and are responsive to the first and second magnetic fields along the shaft for generating logic signals representing the relative position between the movable vehicle frame members. A separate concentrator element is positioned adjacent each of the Hall effect switches for increasing the intensity of the magnetic field in the region of respective switch. Also disclosed is a simplified method for installing the position sensor on the vehicle.

Position sensor

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.

Electric controller having output power limiting circuit

A failsafe system for a skid control system for a multi-axle wheeled vehicle. The skid control system has a plurality of skid control modules, each of which is operatively associated with one of the axles of the vehicle and the skid control modules are operatively coupled by wiring on the vehicle. Each skid control module comprises a skid control circuit for skid controlling the wheels of the associated axle, which circuit is supplied from an electrical power source such as the vehicle battery, either regulated or unregulated. A failsafe circuit is provided in each skid control module and the failsafe circuits of the several modules are connected in cascade fashion to form a chain. An input signal is supplied to the input of the first of the cascaded failsafe circuits and can propagate through the chain of failsafe circuits to the output of the last failsafe circuit only if wiring connecting the modules is proper, the failsafe circuits themselves are operating properly, and electrical power is supplied to each module. A warning occurs when the signal fails to propagate through all the failsafe circuits, and this indicates loss of power or a fault in the modules or the wiring connecting the modules.

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Ann Arbor, MI, United States of America

John S Frait