Anti-roll system with tilt limitations

• US 5,087,073 A
• Filed: 06/06/1991
• Issued: 02/11/1992
• Est. Priority Date: 08/23/1989
• Status: Expired due to Fees

• Current Assignee: TLC Suspension
• Original Assignee: Mark A. Lund
• Inventors: Lund, Mark A.
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US07/711,644
• Time in Patent Office: 250 Days
• Field of Search: 280/772, 280/112.2, 280/689, 280/707
• 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 displacemnt of the pistons in the rear and front wheel cyilnder 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 with upper and lower ports, each of the ports opening into the interior of the cylinder;

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

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

a floating piston assembly sealing said cylinder beneath said lower port, said floating piston assembly being contained in the interior of said cylinder and attached to said cylinder for reciprocal movement therein.

2. The shock absorbing cylinder of claim 1 wherein said floating piston assembly is resiliently biased against reicprocal movement in said cylinder.

3. The shock absorbing cylinder of claim 2 wherein said floating piston assembly is resiliently baised to a greater degree against movement of said piston means away from said lower port than against movement of said piston means toward said lowr port.

4. The shock absorbing cylinder of claim 1 wherein the said floating piston assembly includes:

a substantially cylindrical piece with an annular indentation for providing a liquid seal between the floating piston and the interior of the cylinder;

a through-bore extending diametrically through said cylinder; and

a flexible bushing disposed in the diametric bore flexibly seating the floating piston assembly in the cylinder.

5. The shock absorbing cylinder of claim 4 wherein said floating piston assembly is reciprocally mounted in said cylinder by a fastener extending diametrically through said cylinder and said through-bore.

6. The shock absorbing cylinder of claim 5 wherein said flexible bushing includes a first bushing extending in said through-bore on a first side of said fastener and a second bushing extending in said through-bore on a second side of said fastener, said second flexible bushing being thicker than said first flexible bushing.

7. The shock absorbing cylinder of claim 6 wherein said first flexible bushing is formed from a rubber cylinder and said second flexible bushing is formed from two rubber cylinders.

8. The shock absorbing cylinder of claim 1 further including a second floating piston disposed in said cylinder between said piston means and said upper cylinder port, said second floating piston being slideably mounted for reciprocal movement within said cylinder on a piston rod extending axially in said cylinder, and resiliently biased away from said piston means.

9. The shock absorbing cylinder of claim 8 wherein the second floating piston includes lateral through-ports and a resilient seal covering said through-ports.

10. The shock absorbing cylinder of claim 9 wherein the second floating piston includes a resilient stop between said second floating piston and an end of said cylinder.

11. The shock absorbing cylinder of claim 10 wherein said resilient seal permits only uni-directional fluid flow through said through-bore.

12. The shock absorbing cylinder of claim 1 wherein said piston means port covers are rigid disks and are resiliently biased against the ends of said piston means by resilient biasing elements.

13. The shock absorbing cylinder of claim 12 wherein the resilient biasing force on the port cover at said first end of said piston means is greater than the biasing means on the port cover of said second end of said piston means.

14. The shock absorbing cylinder of claim 1 further including:

a second cylinder mounted to said first cylinder below said lower port and having an interior extending to the interior of said first cylinder.

15. The shock absorbing cylinder of claim 1 wherein said floating piston includes a piston head surface facing toward said lower port and an interior containing an accumulator material, said interior extending from an open end of said floating piston in communication with the interior of said cylinder.

16. The shock absorbing cylinder of claim 15 wherien said floating piston is resiliently biased away from said cylinder.

17. The shock absorbing cylinder of claim 16 wherein said floating piston includes a resilient stop between said floating piston and a lower end of said cylinder.

18. A cylinder assembly comprising:

a cylinder having a fluid containable interior defined by a first end, a second end and a generally cylindrcal wall extending between said first and second cylinder ends;

damping means slideably contained within said cylinder for reciprocal movement within said cylinder between said first and second cylinder ends; and

at least one of said cylinder ends being slideably mounted within said cylinder for reciprocal movement within said cylinder relative to the other cylinder end.

19. The cylinder assembly of claim 18 wherein said slideable cylinder end includes damping means.

20. The cylinder assembly of claim 18 wherein said slideably cylinder end includes a floating piston assembly having means for resiliently biasing said piston assembly against reciprocal movement within said cylinder.

21. An actuator system, comprising:

a cylinder having a fluid containable interior defined by a first end seal, a second end seal and a generally cylindrical wall extending between said first and second cylinder ends;

a primary damper slideably contained within said cylinder for reciprocal movement within said cylinder between said second cylinder end seals; and

a secondary damper providing one of said end seals, said secondary damper providing fluid damping relative to said primary damper.