Differential braking system for tractor trailer trucks

• US 3,894,773 A
• Filed: 09/21/1973
• Issued: 07/15/1975
• Est. Priority Date: 01/05/1972
• Status: Expired due to Term

• Current Assignee: Dixon Cleveland, Lewey O. Gilstrap Jr, Roger L. Barron
• Original Assignee: Dixon Cleveland, Lewey O. Gilstrap Jr, Roger L. Barron
• Inventors: Cleveland, Dixon, Barron, Roger L., Gilstrap, Lewey O. Jr.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Kunin, Stephen G.
• Application Number:
  US05/399,521
• Time in Patent Office: 662 Days
• Field of Search: 180/1,75,82R,103 188/3R,181C 280/400,446B 303/7,20,21 317/5 324/161 340/52R,53,62,263,282
• US Class Current: 303/123
• CPC Class Codes: B60T 2230/06 Tractor-trailer swaying
• CPC Class Codes: B60T 8/1708 for lorries or tractor-trailer combinations
• CPC Class Codes: B60T 8/246 Change of direction
• CPC Class Codes: B60T 8/248 Trailer sway, e.g. for preventing jackknifing

Abstract

The use of differential braking of tractor front wheels in such a way as to maintain negligible angular rates between the tractor and trailer while braking, so as to produce balanced braking forces and to prevent jackknifing.

Claims

1. A method of minimizing the angular rate between a tractor and a trailer, comprising the steps of:

1. measuring a function of the angle between the center lines of the tractor and trailer, 2. obtaining a time derivative of the function of the angle between the center lines of the tractor and trailer, 3. computing one of a differential wheel rotational rate and differential wheel slip command from the result of step (2), 4. measuring one of a function of the wheel rotational rate difference and a function of wheel slip difference between the tractor front wheels, 5. computing the error between commanded and measured values of at least one of said function of wheel rotational rate difference and said function of wheel slip difference, and 6. altering one of the rotational rate and the slip of at least one of said front wheels of the tractor in response to the results of step (5).

2. obtaining a time derivative of the function of the angle between the center lines of the tractor and trailer,

3. A method according to claim 2 wherein the computation of step (3) includes passing the result of step (2) through a high pass filter.

4. measuring one of a function of the wheel rotational rate difference and a function of wheel slip difference between the tractor front wheels,

5. A method according to claim 2 wherein step (6) includes controlling of a tractor braking system having independently variable braking-levels for the front wheels.

6. A method according to claim 1 wherein the computation of step (3) includes passing the result of step (2) through a high pass filter.

7. A method according to claim 6 wherein step (6) includes controlling of a tractor braking system having independently variable braking levels for the front wheels.

8. A method according to claim 1 wherein step (6) includes controlling of a tractor braking system having independently variable braking levels for the front wheels.