DR. THOMAS L. ATKINS, MD
Psychiatric in Ann Arbor, MI

6398321, Jun 4, 2002

Aug 14, 2000

09/471726

Thomas M. Atkins - Ann Arbor MI

Kelsey-Hayes Company - Livonia MI

B60T 866

303158

Reapply pulses for increasing the brake fluid pressure applied to controlled wheel brakes in an anti-lock brake system are generated as a function of vehicle speed. A reapply pulse is generated when the vehicle speed decreases by a predetermined amount.

6443539, Sep 3, 2002

Jun 30, 2000

09/608195

Thomas M. Atkins - Ann Arbor MI

Kelsey-Hayes Company - Livonia MI

B60T 866

303166, 303164, 30312206

The duration and average deceleration of a vehicle wheel are measured during a wheel speed departure and compared to duration and deceleration thresholds to determined if a wheel sneakdown condition exists for the wheel.

4790607, Dec 13, 1988

Jun 15, 1987

7/063361

Thomas M. Atkins - Ann Arbor MI

Kelsey Hayes Company - Romulus MI

B60T 866

303109

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. If, after the isolation valve has been closed, the difference between the actual rear wheel speed and a calculated theoretical speed ramp valve exceeds a predetermined slip threshold, the dump valve is selectively opened to reduce pressure to the rear brakes and correct the wheel slip condition.

4673226, Jun 16, 1987

Feb 19, 1985

6/702765

Peter Every - Livonia MI
Thomas M. Atkins - Ann Arbor MI
Roger L. Miller - Ann Arbor MI
Leonard T. Tribe - Seal Beach CA

Kelsey-Hayes Company - Romulus MI

B60T 866

303109

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. After the isolation valve has been closed and the slip condition is corrected, the computer control module can detect when the vehicle travels from a low friction surface such as wet asphalt to a high friction surface such as a dry concrete, because the braked wheels of the vehicle which are not controlled by the skid control system will cause an increase in deceleration of the vehicle. Under these conditions, pressure to the controlled wheel brakes can generally be increased without causing a lock-up condition.

4886322, Dec 12, 1989

Dec 13, 1988

7/283360

Thomas M. Atkins - Ann Arbor MI

Kelsey Hayes Company - Romulus MI

B60T 866

303109

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 braking of the vehicle, functions to control the application of hydraulic pressure to the rear brakes via the isolation and dump valves in order to correct wheel speed departures and prevent lock-up of the brakes. The computer control is adapted to detect a low to high mu road surface change which occurs during a wheel speed departure, and thereafter applies additional pressure to the rear brakes by selectively opening the isolation valve. Further, the control is adapted to detect when one of the rear wheels remains locked after anti-lock measures have been taken.

4865399, Sep 12, 1989

Dec 13, 1988

7/283689

Thomas M. Atkins - Ann Arbor MI
Brian C. Tuck - Ann Arbor MI
Edward N. Fuller - Manchester MI
Peter Every - Livonia MI

Kelsey Hayes Company - Romulus MI

B60T 840, B60T 850

303116

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. The control cyclically moves the valve between the first and second positions during a predetermined time period to alternately increase and decrease pressure to the wheel brake.

6193327, Feb 27, 2001

Dec 23, 1999

9/471725

Thomas M. Atkins - Ann Arbor MI

Kelsey-Hayes Company - Livonia MI

B60T 834

3031131

The speed of a controlled wheel in a rear wheel anti-lock brake system is monitored during a spin-and-brake condition. Acceleration of the rear wheel following a string of dump pulses is an indication that the spin-and brake condition ended before the vehicle brakes were applied. A lack of acceleration of the rear wheel following a string of dump pulses is an indication that the spin-and-brake condition is present.

3981543, Sep 21, 1976

Apr 7, 1975

5/565556

Thomas M. Atkins - Ann Arbor MI

Kelsey-Hayes Company - Romulus MI

B60T 802

303 21AF

A hydraulically operated automotive skid control system. The system includes a regulator that regulates pump pressure that operates on the modulator in response to variations in braking system pressure. A combined bypass and isolation valve is incorporated for providing a direct source of actuating fluid in the event of failure of the pump to maintain adequate pressure.

3963276, Jun 15, 1976

Aug 24, 1973

5/391463

Thomas M. Atkins - Ann Arbor MI

Kelsey-Hayes Company - Romulus MI

B60T 802

303 21AF

A vehicular skid control system for relieving the brake pressure when an incipient skid condition is sensed. The system includes a combined check and bleed valve between the master cylinder and rear wheel brakes, a modulator assembly actuable by a ancillary source of fluid pressure, a fal safe bypass valve for communicating unmodulated master cylinder pressure directly to the rear brakes upon failure of the ancillary pressure source, and a regulator provided in the circuit connecting the source of ancillary fluid with the expansion chamber for maintaining at least a predetermind pressure in the circuit. Certain of the elements of the system may be automatically cycled each time the vehicle engine is started and stopped.