Tractor-trailer brake control system

• US 4,804,237 A
• Filed: 08/17/1987
• Issued: 02/14/1989
• Est. Priority Date: 04/27/1987
• Status: Expired due to Term

• Current Assignee: Mid-America Commercialization Corporation
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Sullivan, Mark W., Gee, Thomas A.
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): Newholm, Timothy
• Application Number:
  US07/086,334
• Time in Patent Office: 547 Days
• Field of Search: 280/DIG. 14, 280/432, 280/433, 188/3 R, 188/112, 188/195, 188/181 A, 303/6 M, 303/7, 303/14-17, 303/20, 303/22 A, 303/22 R, 303/93, 303/97, 303/100, 303/106, 303/9.76, 303/9.69, 303/22.1
• US Class Current: 303/7
• CPC Class Codes: B60T 13/66 Electrical control in fluid-pressure brake systems
• 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
• CPC Class Codes: B60T 8/1708 for lorries or tractor-trailer combinations
• CPC Class Codes: B60T 8/248 Trailer sway, e.g. for preventing jackknifing
• CPC Class Codes: B60T 8/268 using the valves of an ABS, ASR or ESP system
• CPC Class Codes: B62D 53/0807 adjustable coupling saddles mounted on sub-frames; Mounting plates therefor
• CPC Class Codes: F16D 2066/001 Temperature
• CPC Class Codes: F16D 2066/005 Force, torque, stress or strain

Abstract

A tractor (28) semi-trailer (30) brake system control for distributing brake effort to obtain inter-tractor-trailer balanced and proportional braking, depending upon the magnitude of operator demand for braking effort, is provided. The control utilizes sensors (80, 170, 172) provided solely on the tractor.

Claims

1. A control system for a tractor-trailer brake system on a tractor-trailer vehicle having an independently controllable tractor sub-vehicle brake system, a fifth wheel connection on the tractor for engaging a king pin carried by a trailer sub-vehicle and means for controlling an independently controllable trailer sub-vehicle brake system, said control system characterized by:

first sensing means mounted on said tractor for providing input signals indicative of the value of the horizontal force and of the value of the vertical force at the fifth wheel/king pin connection,

second sensing means mounted on said tractor for providing an input signal indicative of the acceleration of the vehicle;

third sensing means mounted on said tractor for providing an input signal indicative of the level of braking effort demand by the operator; and

a control unit having means for receiving said input signals and for processing said signals in accordance with predetermined logic rules to issue command output signals and actuators responsive to said command output signals for modulating a controlled parameter at each sub-vehicle brake system related to the brake force at the sub-vehicle brake system;

said logic rules comprising;

rules by which the trailer mass is estimated on the basis of sensed values of horizontal force at the fifth wheel/king pin connection during nonbraking vehicle acceleration;

rules by which an input signal indicative of application force applied to each trailer brake is sensed and and compared to predetermined brake performance reference parameters to estimate an average characteristic for the trailer brakes on a trailer;

rules by which said demand input signal is compared to a first reference value and if said demand signal is less than said first reference signal, said trailer brakes and said tractor brakes are caused to be applied such that the average value at the trailer brakes of a selected parameter indicative of brake wear is related to the average value of said parameter at the tractor brakes in a predetermined manner.