Acoustic signal transmission between a tractor and trailer within the air brake system

• US 5,090,779 A
• Filed: 08/27/1990
• Issued: 02/25/1992
• Est. Priority Date: 08/27/1990
• Status: Expired due to Term

• Current Assignee: ArvinMeritor Technology LLC (Meritor, Inc. (Nevada))
• Original Assignee: Rockwell International Corporation
• Inventors: Kramer, Dennis A.
• Primary Examiner(s): Oberleitner, Robert J.
• Assistant Examiner(s): Muratori, Alfred
• Application Number:
  US07/573,938
• Time in Patent Office: 547 Days
• Field of Search: 188/1.11, 303/7, 303/20, 303/86, 303/91, 303/92, 381/154
• US Class Current: 303/7
• CPC Class Codes: B60T 17/22 Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: B60T 8/90 using a simulated speed signal to test speed responsive control means
• CPC Class Codes: H04B 11/00 Transmission systems employing sonic, ultrasonic or infrasonic waves

Abstract

A technique for acoustically communicating through existing air brake lines between a tractor and a trailer. The diagnostic status of the trailer antilock system is communicated via acoustic signals from the trailer antilock system through the air brake lines of the trailer and into the tractor air brake line. A piezo crystal located in the tractor air brake line converts the acoustic signal into an electrical signal which may be used to illuminate a lamp providing a display on the tractor dashboard.

Claims

1. An apparatus for communicating trailer antilock system diagnostic status to a tractor operator through an existing air brake line comprising:

means for generating and transmitting an acoustic signal in said air brake line in a trailer in response to a predefined diagnostic status of said antilock system;

means for receiving said acoustic signal disposed on said air brake line on a tractor; and

means for displaying receipt of said signal in direct view of said tractor operator.

2. An apparatus in claim 1 wherein said means for generating comprises a frequency source and a piezo crystal.

3. An apparatus as in claim 1 wherein said means for receiving comprises a piezo crystal.

4. An apparatus as in claim 1 wherein said means for displaying receipt of said signal comprises a light displayed on a dashboard of said tractor.

5. An antilock brake system for a tractor-trailer comprising:

a microprocessor for controlling an antilock function of a trailer;

a relay valve for modulating trailer brake force in response to control by said microprocessor;

a diagnostic means for producing a signal in response to verification of preselected performance parameters of said microprocessor;

means for generating an acoustic signal in an air brake line in said trailer in response to lack of verification of preselected performance parameters;

means for receiving said acoustic signal in said air brake line on a tractor; and

means for displaying receipt of said acoustic signal in direct view of a vehicle operator.

6. An apparatus as in claim 5 wherein said means for generating comprises a frequency source and a piezo crystal.

7. An apparatus as in claim 5 wherein said means for receiving comprises a piezo crystal.

8. An apparatus as in claim 5 wherein said means for displaying receipt of said signal comprises a light displayed on a dashboard in said tractor.

9. An apparatus for communicating a trailer antilock system status to a tractor through existing air brake lines comprising:

a voltage to frequency convertor for providing a frequency signal in response to a preselected trailer antilock system status;

a first piezo crystal disposed in an air brake line of a trailer and connected to a frequency convertor;

a second piezo crystal disposed in said air brake line on

said tractor;

a frequency to voltage convertor connected to said second piezo crystal; and

a warning indicator connected to said frequency to voltage convertor and positioned to provide notification of trailer antilock system status to an operator of said tractor.

10. An apparatus as in claim 9 wherein said warning indicator is a light which is latched on upon receiving an initial signal to provide a continuous uninterrupted display.

11. A method of continuously providing trailer antilock system diagnostic status to a tractor operator operating a tractor-trailer combination comprising the steps of:

receiving a first signal from a trailer antilock system in response to said antilock system providing indication of a predefined diagnostic status;

generating an acoustic signal in response to receipt of said first signal;

transmitting said acoustic signal through air lines of said tractor-trailer;

receiving said acoustic signal at a tractor;

converting said acoustic signal to a voltage signal; and

displaying said voltage signal to provide notification of trailer antilock system status to said tractor operator.