Anti-roll system with tilt limitation

• US 5,174,603 A
• Filed: 12/18/1991
• Issued: 12/29/1992
• Est. Priority Date: 08/23/1989
• Status: Expired due to Fees

• Current Assignee: TLC Suspension
• Original Assignee: Tilt Limitation Control
• Inventors: Lund, Mark A.
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US07/809,395
• Time in Patent Office: 377 Days
• Field of Search: 280/772, 280/112.2, 280/689, 280/707, 280/DIG. 1, 180/41
• US Class Current: 188/266.2
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 21/06 fluid
• CPC Class Codes: B60G 2202/24 Fluid damper
• CPC Class Codes: B60G 2204/80 Interactive suspensions; arrangement affecting more than one suspension unit
• CPC Class Codes: B60G 2400/25 Stroke; Height; Displacement
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/40 Steering conditions
• CPC Class Codes: B62D 9/02 combined with means for inwardly inclining vehicle body on bends
• CPC Class Codes: F16F 9/49 Stops limiting fluid passage, e.g. hydraulic stops or elastomeric elements inside the cylinder which contribute to changes in fluid damping fluid-actuated displacement devices with means for accelerating or decelerating the stroke F15B15/22
• CPC Class Codes: F16F 9/512 Means responsive to load action, i.e. static load on the damper or dynamic fluid pressure changes in the damper, e.g. due to changes in velocity F16F9/504, F16F9/516 take precedence; non-automatic damper adjustment from a distance using servo control, the servo pressure being created by the flow of damping fluid F16F9/465; self-pumping fluid springs in vehicle suspensions B60G17/044

Abstract

An anti-roll system for turn compensation in a vehicle generates a differential hydraulic signal in which a pressurizing potential corresponds to a first curve direction and a complementary return hydraulic potential. The system includes a pair of rear wheel cylinder and piston assemblies and a pair of front wheel cylinder and piston assemblies. A hydraulic circuit is connected to conduct the pressurizing potential to move the pistons in a first rear wheel cylinder and piston assembly and a first front wheel cylinder and piston assembly, while conducting the return signal to move the pistons in second front wheel cylinder and piston assembly and a second rear wheel cylinder and piston assembly. A hydraulic conductor directly connects corresponding ends of the rear wheel cylinder and piston assemblies to provide a hydraulic conduction between those assemblies in response to conduction of the differential hydraulic signal. A tilt limitation feature is provided in the front wheel cylinder and piston assemblies and is connected to the hydraulic circuit for limiting the maximum displacement of the pistons in the rear and front wheel cylinder and piston assemblies. In a vehicle, the system reacts to a turn by causing the front and rear wheel cylinder and piston assemblies to tilt the vehicle in a direction to counteract the vehicle rolling force caused by the turn. The tilt-limitation element operates to limit the amount of tilt produced by the system of the invention to counteract vehicle roll force.

Claims

1. A cylinder and piston assembly, comprising:

a cylinder having an upper end, a lower end, and upper and lower ports, each of the ports opening into an interior of the cylinder;

a piston slideably contained within said cylinder interior for reciprocal, hydraulically-actuated movement between said ports;

a floating piston assembly disposed between said piston and said cylinder upper end, said floating piston assembly being mounted for reciprocal movement in said cylinder.

2. The cylinder and piston assembly of claim 1 wherein said piston and said floating piston assembly are mounted on a common piston rod.

3. The cylinder and piston assembly of claim 2 wherein said floating piston assembly includes means for resiliently biasing said floating piston assembly away from said piston.

4. The cylinder and piston assembly of claim 3 wherein said floating piston assembly includes a through-bore and a resilient seal covering said through-bore.

5. The cylinder and piston assembly of claim 4 wherein said floating piston assembly includes a resilient stop between said floating piston assembly and the upper end of said cylinder.

6. The cylinder and piston assembly of claim 5 wherein said resilient seal provides a means for permitting only uni-directional fluid flow through said through-bore.

7. The cylinder and piston assembly of claim 1 wherein said floating piston assembly includes a bi-directional fluid path.

8. The cylinder and piston assembly of claim 1 wherein said floating piston assembly includes a uni-directional fluid path.

9. The cylinder and piston assembly of claim 1 wherein said floating piston assembly includes a bi-directional fluid path and a uni-directional fluid path.

10. The cylinder and piston assembly of claim 7 wherein said bi-directional fluid path includes an annular space between said floating piston assembly and an interior wall of said cylinder.

11. The cylinder and piston assembly of claim 8 wherein said uni-directional fluid path includes a pair of 90-degree through-ports in said floating piston assembly and a resilient ring seated over said through-ports.

12. The cylinder and piston assembly of claim 1 wherein said floating piston assembly includes a lower biasing system.

13. The cylinder and piston assembly of claim 1 wherein said floating piston assembly includes an upper biasing system.

14. The cylinder and piston assembly of claim 1 wherein said floating piston assembly includes a lower biasing system and an upper biasing system.

15. The cylinder and piston assembly of claim 12 wherein said lower biasing system includes a rubber spring disposed between said floating piston assembly and said piston.

16. The cylinder and piston assembly of claim 15 wherein said floating piston assembly includes an annular cup-shaped floating piston structure having a cylindrical cut-out center portion including a bottom surface which contacts an upper end of said rubber spring.

17. The cylinder and piston assembly of claim 16 wherein said floating piston structure includes a pair of 90-degree through-ports extending upwardly from said bottom surface and then outwardly to an annular surface portion of said floating piston structure.

18. The cylinder and piston assembly of claim 17 wherein said 90-degree through-ports extend to an annular groove formed in an upper annular portion of said floating piston structure, and wherein said floating piston assembly further includes a resilient ring covering said annular groove to form a uni-directional fluid path through said 90-degree through-ports.

19. The cylinder and piston assembly of claim 18 further including a resilient stop positioned between said upper annular portion of said floating piston structure and said upper end portion of said cylinder.

20. A cylinder and piston assembly, comprising:

a cylinder having an upper end, a lower end and upper and lower cylinder ports, each of the cylinder ports opening into an interior of the cylinder;

a piston slideably contained within said cylinder for a reciprocal, hydraulically-actuated movement within said cylinder between said cylinder ports;

a first piston port opening between each end of said piston, a first port cover attached to a first end of said piston and biased against said first end of said piston to cover one end of said first piston port;

a second piston port opening between each end of said piston, and a second port cover attached to a second end of said piston and biased against said second end of said piston to cover one end of said second port; and

a floating piston assembly disposed between said piston and said cylinder upper end, said floating piston assembly being mounted for reciprocal movement within said cylinder and being positionable with respect to said piston.

21. A cylinder and piston assembly, comprising:

a cylinder having an upper end and a lower end, an upper port and a lower port, each of the ports opening into an interior of the cylinder between said upper and lower ends thereof;

a piston slideably contained within said cylinder for reciprocal, hydraulically-actuated movement within said cylinder between said ports, said piston being mounted on a piston rod;

a floating piston assembly mounted on said piston rod between said piston and the upper end of said cylinder, said floating piston assembly being mounted for movement on said piston rod independently of said piston;

said floating piston assembly including an annular cup-shaped floating piston structure having upper and lower diametrically extending surfaces, a first annular surface extending between said upper and lower diametrically extending surfaces and a second annular surface extending between said lower diametrically extending surface and said piston;

said floating piston structure including a bi-directional fluid path formed by an annular space between said second annular surface and an interior surface of said cylinder;

said floating piston structure also including a uni-directional fluid path formed by a pair of 90-degree through-ports extending upwardly from said lower diametrically extending surface and thence radially outwardly to said first annular surface, said first annular surface further including an annular groove through which said 90-degree through-ports extend;

said floating piston assembly also including a ring seated in said annular groove, said seated ring being resilient in nature and configured for deflecting outwardly from said annular groove in response to fluid exiting through said annular groove and for seating inwardly toward said annular groove in response to a hydraulic material moving in an opposite direction; and

said floating piston assembly further including a resilient O-ring stop positioned on said upper diametrically extending surface and around said piston rod.