TRAILER SWAY CONTROL SYSTEM

• US 3,819,234 A
• Filed: 03/06/1972
• Issued: 06/25/1974
• Est. Priority Date: 03/06/1972
• Status: Expired due to Term

• Current Assignee: Roger E. Doerfler, William J. Couchois
• Original Assignee: Roger E. Doerfler, William J. Couchois
• Inventors: Doerfler, Roger E., Couchois, William J.
• Primary Examiner(s): Buchler, Milton
• Assistant Examiner(s): Kunin, Stephen G.
• Application Number:
  US05/231,976
• Time in Patent Office: 841 Days
• Field of Search: 180/103-104 200/61.46,8R,8A 303/7,20
• US Class Current: 303/20
• 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 8/248 Trailer sway, e.g. for preventing jackknifing

Abstract

A system for detecting the occurrence of an incipient, excessive sway condition of a trailer and for automatically applying the trailer brakes to inhibit and/or correct the sway condition.

Claims

1. In a wheeled vehicle adapted to be towed by a towing vehicle and having a brake system actuable for braking at least one wheel of the vehicle, the invention comprising:

angular acceleration sensor means for sensing the actual magnitude of angular acceleration of the towed vehicle, brake operating means operatively connected with said angular acceleration sensing means and responsive to angular acceleration of a preselected magnitude for actuating the brake for at least the one wheel of the vehicle.

2. The invention of claim 1 with said angular acceleration sensing means comprising housing means adapted to be secured to the towed vehicle, rotor means comprising a disk supported for rotation relative to said housing means, fluid means comprising a fluid located in said housing for coupling said disk and said fluid whereby the relative rotation of said disk and said housing means provides an indication of the angular acceleration of the towed vehicle, and with said brake operating means responsive to the relative rotation between said disk and said housing means for actuating the brake.

3. The invention of claim 2 with said disk comprising coupling means coupling said disk to said liquid.

4. The invention of claim 3 with said coupling means comprising a plurality of ribs fixed to said disk.

5. The invention of claim 2 further comprising resilient means connected to said housing means and said rotor means for opposing rotation of said disk relative to said housing means.

6. The invention of claim 2 with said disk being substantially immersed in said liquid and with said liquid and with said disk having generally the same specific gravity.

7. The invention of claim 6 with said liquid having a low freezing point such that it will not freeze at atmospheric temperatures.

8. The invention of claim 6 with said resilient means comprising a spring engaging said disk with a minimum contact area whereby frictional losses are minimized.

9. The invention of claim 2 with said brake operating means responsive to said disk attaining a first preselected positional relationship relative to said housing for actuating the brake and responsive to a second preselected positional relationship for deactuating the brake.

10. The invention of claim 9 with said brake operating means comprising time delay means for delaying deactuating of the brake for a preselected time duration after attainment of said second preselected positional relationship.

11. The invention of claim 9 with said first preselected positional relationship being an amount of relative rotation greater than around 3.5*.

12. The invention of claim 9 with said first preselected positional relationship being attained in response to angular acceleration of the towing vehicle of around 1.4 rad/sec.2.

13. The invention of claim 12 with Said first preselected positional relationship being an amount of relative rotation greater than around 3.5*.

14. The invention of claim 1 with said angular acceleration sensing means comprising an enclosed housing, a disk located within said housing and supported therein for rotation relative to said housing, a liquid substantially filling said housing and substantially surrounding said disk, means coupling said disk and said liquid whereby pivoting of the towing vehicle results in relative rotation between said disk and said housing means for providing an indication of the angular acceleration of the towed vehicle, said brake operating means responsive to the relative rotation between said disk and said housing means for actuating the brake.

15. The invention of claim 14 with said liquid and said disk having generally the same specific gravity.

16. The invention of claim 15 with said liquid having a low freezing point such that it will not freeze at atmospheric temperatures.

17. The invention of claim 14 further comprising resilient means for resiliently resisting relative rotation of said disk.

18. The invention of claim 17 with said resilient means comprising a spring engaging said disk with a minimum contact area whereby frictional losses are minimized.

19. The invention of claim 1 with said preselected magnitude of angular acceleration being around 1.4 rad/sec.2.

20. The invention of claim 1 with said brake operating means actuating the brake to a magnitude less than that magnitude which would provide locked wheel.

21. The invention of claim 1 with the brake being an electrically actuated brake and with said brake operating means actuating that brake by providing a preselected magnitude of current with said preselected magnitude of current being less than that which would result in a locked wheel condition.

22. In a wheeled vehicle adapted to be towed by a towing vehicle and having a brake system electrically actuable for braking at least one wheel of the vehicle, the invention comprising:

an enclosed housing, a disk located within said housing and supported thereon for rotation relative to said housing a liquid substantially filling said housing and substantially surrounding said disk, means coupling said disk and said liquid whereby pivoting of the towing vehicle results in relative rotation between said disk and said housing means, resilient means connected to said housing for opposing rotation of said disk relative to said housing means whereby the magnitude of relative rotation will be a function of the magnitude of the angular acceleration of the towing vehicle, circuit means for providing an electrical output signal to actuate the brake for at least the one wheel, said circuit means comprising sensing means for sensing the relative positional relationship between said disk and said housing and for providing an indicating signal in response to said disk and said housing attaining a preselected positional relationship indicative of an incipient excessive sway condition of the towing vehicle, said circuit means comprising output circuit means for providing said output signal in response to said indicating signal.

23. The apparatus of claim 22 with said actuating signal having a magnitude less than that magnitude which would lock the brakes of the at least one wheel.

24. The apparatus of claim 23 with said coupling means comprising a plurality of ribs on said disk.

25. The apparatus of claim 22 with said resilient means comprising a spring member supported in cantilever fashion on said housing, said spring member having a first convexly, arcuate portion, said disk having a second convexly arcuate portion in confrontation with said first arcuate portion, said first and second arcuate portion engageable with each other to provide a minimum contact area whereby friction therebetween is minimized.

26. The apparatus of claim 25 with said coupling means comprising a plurality of ribs on said disks, said resilient mEans comprising a triangularly shaped wire member open at its apex and straddling one of said ribs with the base of said wire member supported on said housing and with said wire member having two legs like said spring member on opposite sides of said one of said ribs.

27. The apparatus of claim 22 with said sensing means comprising a light emitting diode and a photoresponsive member located on opposite sides of said disk, said disk having windows in between said diode and photoresponsive member whereby relative rotation of said disk can be detected.

28. The apparatus of claim 26 with said housing having transparent window portions located in line with said windows and with said diode and said photoresponisve member located externally of said housing on opposite sides of said window portions.

29. The apparatus of claim 28 with said disk being opaque at least in the location of said windows and with said liquid being effectively transparent.

30. The apparatus of claim 22 with said output circuit means comprising time delay means for providing a preselected time delay in response to said disk and said housing moving out of said preselected positional relationship indicative of correction of said incipient sway condition.

31. The apparatus of claim 22 with said time delay being .25 and .50 second.