Electronic trailer brake controller

• US 6,039,410 A
• Filed: 01/09/1998
• Issued: 03/21/2000
• Est. Priority Date: 01/10/1997
• Status: Expired due to Term

• Current Assignee: Hayes Brake Controller Co. LLC (Syncro Corp.)
• Original Assignee: Hayes Lemmerz International Incorporated (Iochpe-Maxion SA)
• Inventors: McGrath, Michael C., Hedding, Michael A., Robertson, Charles L.
• Primary Examiner(s): Dickson, Paul N.
• Assistant Examiner(s): WOLLER, JEFFREY ALAN
• Application Number:
  US09/004,984
• Time in Patent Office: 802 Days
• Field of Search: 303/3, 303/7, 303/15, 303/20, 303/122.04, 303/122.05, 303/124, 303/138, 188/1.11 R, 188/1.11 E, 188/3 R
• US Class Current: 303/7
• CPC Class Codes: B60T 7/20 specially for trailers, e.g. in case of uncoupling of or overrunning by trailer inertia-actuated overrun brakes B60T13/08

Abstract

An electronic controller for actuating electric wheel brakes on a towed vehicle which includes a device for sensing the electric current flowing to the towed vehicle wheel brakes. The device is operative to interrupt the flow of electric current if the current flow becomes excessive. The controller also retains gain settings if the supply of power to the controller is interrupted and has a visual display for indicating results of self-diagnostic testing.

Claims

1. A trailer brake controller comprising:

a brake control signal generator for generating a brake control signal;

a microprocessor connected to said brake control signal generator and responsive to said brake control signal to generate an output brake actuation signal which is related to said brake control signal by a brake controller gain;

a memory connected to said microprocessor;

said memory storing a plurality of predetermined brake controller gains; and

a gain control for producing a gain control signal, said gain control connected to said microprocessor, said gain control operable by a vehicle operator to select a gain control signal, said gain control maintaining said selected gain control signal once said gain control is set by said operator, said microprocessor being responsive to said gain control signal to select one of said predetermined gains from said memory for said brake controller gain.

2. A trailer brake controller comprising:

a brake control signal generator for generating a brake control signal;

a microprocessor connected to said brake control signal generator and responsive to said brake control signal to generate an output brake actuation signal which is related to said brake control signal by a controller gain;

a memory connected to said microprocessor;

said memory storing a plurality of predetermined gains; and

a gain control for producing a gain control signal, said gain control connected to said microprocessor, said gain control including a potentiometer having a variable resistance and said gain control signal being a voltage appearing across a portion of said potentiometer, said potentiometer being adjustable by a vehicle operator to vary said gain control, said gain control maintaining said gain control signal once set by said operator, said microprocessor being responsive to said gain control signal to select one of said predetermined gains from said memory for said controller gain.

3. A trailer brake controller comprising:

a brake control signal generator for generating a brake control signal;

a microprocessor connected to said brake control signal generator and responsive to said brake control signal to generate an output brake actuation signal which is related to said brake control signal; and

a visual display connected to said microprocessor, said microprocessor operative to visually display indicators upon said visual display related to the trailer brake controller operation.

4. A trailer brake controller according to claim 3 wherein said displayed indicators are diagnostic in nature.

5. A trailer brake controller according to claim 4 wherein said displayed indicators include warning devices which are indicative of a malfunctioning component in the brake controller.

6. A trailer brake controller comprising:

a brake control signal generator for generating a brake control signal said brake control signal generator being adapted to be mounted in a towing vehicle;

a microprocessor connected to said brake control signal generator and responsive to said brake control signal to generate an output brake actuation signal which is related to said brake control signal;

a sensor for detecting deceleration of said towing vehicle, said sensor connected to said brake control signal generator and operable to generate a null signal when said towing vehicle is at rest;

an adjustable null offset signal generator connected to said brake control signal generator for generating a null offset signal, said null offset signal generator maintaining said null offset signal at a value corresponding to a setting of said null offset signal generator to cancel said sensor null signal, said microprocessor including a brake signal generator calibration subroutine for displaying calibration data upon said visual display for adjustment of said null offset signal generator when said microprocessor is connected to a selection device for actuating said brake signal generator calibration subroutine; and

a visual display connected to said microprocessor, said microprocessor operative to visually display indicators related to controller operation.

7. A trailer brake controller according to claim 6 wherein said adjustable null offset generator includes a potentiometer having a variable resistance and said null offset signal is a voltage appearing across a portion of said potentiometer, said potentiometer being adjustable to vary said null offset signal.

8. A trailer brake controller according to claim 7 wherein said selection device is a removable jumper connected between a calibration pin on said microprocessor and ground, said brake signal generator calibration subroutine being actuated when said jumper is in place.

9. A trailer brake controller according to claim 7 wherein said selection device is a switch having an open position and a closed position, said switch connected between a calibration pin on said microprocessor and ground, said brake signal generator calibration subroutine being actuated when said switch is in said closed position.

10. A trailer brake controller for supplying electrical current to a trailer wheel brake, the controller comprising:

a brake control signal generator for generating a brake control signal;

a control device connected to said brake control signal generator and responsive to said brake control signal to generate an output brake actuation signal which is related to said brake control signal; and

an output current limiter connected to said control device and adapted to monitor the magnitude of the current being supplied by the controller to the trailer wheel brake, said limiter including a hall effect device for sensing the strength of the magnetic field generated by the current and being operative to cause the control device to interrupt the current when the magnetic field strength exceeds a predetermined value.

11. A trailer brake controller according to claim 10 wherein said output current limiter further includes a metal hoop which includes a circular portion, said circular portion encircling a wire which conducts electric current to the trailer wheel brake, said hoop further having first and second ends extending from said circular portion, said hall effect device being slidably disposed between said first and second ends of said hoop.

12. A trailer brake controller according to claim 11 wherein said hoop is carried by a housing, said housing having a channel formed therein, said channel receiving said first and second ends of said hoop and said hall effect device, said housing being movable relative to said hall effect device such that said first and second ends of said hoop can be moved relative to said hall effect device to calibrate said output current limiter.

13. A trailer brake controller according to claim 12 is wherein said hoop is formed from a flat strip of metal and further wherein said first end of said hoop is flat and said second end of said hoop is L-shaped.

14. A trailer brake controller according to claim 13 wherein said L-shaped end of said second end of said loop is tapered to concentrate said magnetic field.

15. A trailer brake controller according to claim 14 wherein said control device includes a microprocessor.

16. A trailer brake controller according to claim 14 wherein said control device includes an analog brake controller circuit.

17. A trailer brake controller according to claim 14 wherein said control device includes a brake actuator.

18. A trailer brake controller according to claim 12 wherein said hoop is formed from a length of wire.

19. A trailer brake controller comprising:

a first manual brake control signal generator for generating a first manual brake control signal;

a second manual brake control signal generator for generating a second manual brake control signal;

a microprocessor connected to said first and second manual brake control signal generators and responsive to one of said first or second manual brake control signals to generate an output brake actuation signal which is related to said one of said first or second manual brake control signals, said microprocessor operative to monitor said first and second manual brake control signal generators for a malfunction; and

a warning device connected to said microprocessor, said microprocessor operative to actuate said warning device upon detection of a malfunction of one of said first or second manual brake control signal generators to indicate which manual brake signal generator has malfunctioned.

20. A trailer brake controller according to claim 19 wherein said microprocessor includes a first manual brake signal input port and a second manual brake signal input port and further wherein said first manual brake control signal generator is connected to said first manual brake signal input port and second manual brake control signal input port is connected to said second manual brake signal input port.

21. A trailer brake controller according to claim 20 wherein said warning device includes a visual display.

22. A trailer brake controller comprising:

a brake control signal generator for generating a brake control signal;

a microprocessor connected to said brake control signal generator and responsive to said brake control signal to generate an output brake actuation signal at an output terminal which is related to said brake control signal;

a brake switching circuit adapted to be connected between a power supply and a set of trailer brakes, said brake switching circuit having a control input terminal connected to said microprocessor output terminal, said brake switching circuit responsive to said output brake actuation signal to supply an electric current from said power supply to said trailer brakes which is a function of said brake actuation signal; and

a monitoring circuit connected to said brake switching circuit and to an error pin on said microprocessor, said monitoring circuit operative upon a malfunction of said brake switching circuit to generate a malfunction signal and apply said malfunction signal to said error pin.

23. A trailer brake controller according to claim 22 further including a warning device, said microprocessor being responsive to said malfunction signal to actuate said warning device.

24. A trailer brake controller according to claim 23 wherein said warning device includes a visual display.

25. A controller for trailer brakes having return springs for releasing the brakes, the controller comprising:

a brake control signal generator for generating a brake control signal;

a microprocessor connected to said brake control signal generator and responsive to said brake control signal to generate an output brake actuation signal which is related to said brake control, said microprocessor continuously generating a predetermined minimum signal sufficient to overcome tension in the brake return springs.