BRAKING SYSTEM

• US 20080001470A1
• Filed: 07/18/2006
• Published: 01/03/2008
• Est. Priority Date: 06/01/2006
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Craig, William, Fitzgibbons, Patrick
• Granted Patent: US 7,367,633 B2
• Time in Patent Office: Days
• US Class Current: 303/3
• CPC Class Codes: B60T 13/588 both fluid and mechanical assistance or drive
• CPC Class Codes: B60T 17/18 Safety devices; Monitoring
• CPC Class Codes: F16D 2121/24 using motors
• CPC Class Codes: F16D 2127/06 Locking mechanisms, e.g. acting on actuators, on release mechanisms or on force transmission mechanisms
• CPC Class Codes: F16D 2129/12 Electrostrictive or magnetostrictive elements, e.g. piezoelectric
• CPC Class Codes: F16D 65/18 adapted for drawing members together , e.g. for disc brakes

Abstract

Disclosed is a redundant braking system for a vehicle. A controller may monitor a status of a hydraulic braking system, and during vehicle travel, automatically switch to a modulated electric braking system which is separate from the hydraulic braking system when the hydraulic braking system fails. The modulated electric braking system may utilize a brake acting on a drive shaft of the vehicle, and an operator-actuated switch may set a mode of the modulated electric braking system to a non-modulated parking brake mode.

Claims

1. A system for braking a truck, the system comprising:

a foot brake pedal configured to receive a continuously variable force applied to the foot brake pedal;

a transducer operatively coupled to the foot brake pedal and configured to convert the continuously variable force to an electronic signal of a magnitude proportional to the continuously variable force;

a brake force apparatus located on an input side of a torque transfer unit and configured to apply brake force to a drive shaft of the truck, the brake force apparatus including a disc brake attached directly to the drive shaft;

a control unit configured to control the brake force apparatus to apply continuously variable modulated brake force to the drive shaft of the truck via the disc brake in an amount proportional to the continuously variable force applied to the foot brake pedal;

means for transmitting the electronic signal from the transducer to the control unit; and

a finger-actuated button accessible to a driver of the truck, the button configured to set a mode of the system to a non-modulated parking brake mode in which the control unit causes the brake force apparatus to apply and maintain a ratcheted force to the drive shaft of the truck, the ratcheted force being maintained at a constant level even if the truck is powered off.

2. A system for braking a vehicle, the system comprising:

an operator-actuated switch for selecting a silent mode of operation;

a foot brake pedal configured to receive a continuously variable force applied to the foot brake pedal; and

a modulated brake force apparatus configured to act directly on a drive shaft of the vehicle and provide continuously variable braking force to the drive shaft in response to the continuously variable force applied to the foot brake pedal and in response to activation of the operator-actuated switch for selecting a silent mode of operation.

3. The system of claim 2, wherein the modulated brake force apparatus is located on an input side of a torque transfer unit.

4. The system of claim 2, further including an operator-actuated switch for setting a mode of the system to a non-modulated parking brake mode, and further comprising a parking brake apparatus configured to act on the drive shaft in the non-modulated parking brake mode.

5. The system of claim 4, wherein the parking brake apparatus is configured to apply a constant force to the drive shaft once the operator-activated switch is actuated.

6. The system of claim 5, wherein said parking brake apparatus comprises a ratcheting mechanism.

7. The system for modulated braking of claim 2, wherein the modulated brake force apparatus includes a brake selected from a drum brake and a disc brake attached directly to the drive shaft.

8. The system for modulated braking of claim 2, further comprising slip differentials.

9. The system for modulated braking of claim 2, further comprising locking differentials.

17. The system of claim 2 wherein the modulated brake force apparatus is a disc brake attached directly to the drive shaft of the vehicle.

18. The system of claim 17 further comprising a hydraulic system configured to convert the continuously variable force applied to the brake pedal to a continuously variable force applied to the disc brake attached directly to the drive shaft of the vehicle.

19. The system of claim 17 further comprising an electronic system configured to convert the continuously variable force applied to the brake pedal to a continuously variable force applied to the disc brake attached directly to the drive shaft of the vehicle.

20. The system of claim 4 wherein the operator-activated switch comprises a finger-actuated button in electronic communication with the parking brake apparatus via an electronic controller.

10. A method of braking a vehicle, the method comprising:

receiving a continuously variable force applied to a brake pedal;

converting the continuously variable force applied to the brake pedal to a different type of force; and

providing the different type of force to a brake apparatus acting directly on a drive shaft of the vehicle,

wherein the brake apparatus is located on an input side of a torque transfer unit, the method further includes actuating an operator-actuated switch for setting a mode of the system to a non-modulated parking brake mode, and in said parking brake mode a ratcheting mechanism of said brake apparatus maintains a constant braking force applied to the drive shaft when the vehicle is powered off.

15. The method of claim 10, wherein the brake apparatus includes a brake selected from a drum brake and a disc brake attached directly to the drive shaft.

16. The method of claim 15 wherein the continuously variable force applied to the brake pedal is converted to the different type of force via a hydraulic system connecting the brake pedal to the brake apparatus acting directly on the drive shaft of the vehicle.

11-14. -14. (canceled)